Advanced therapy in thoracic surgery - part 4 pot

Surgical Management of Congenital Lesions of the Lung / 165 most likely to present in the perinatal period as a result of displacement of normal lung and impaired respiration If peripheral lesions cause airway obstruction, postobstructive infections or lobar hyperinflation may develop When airway blockage is more central, significant hyperinflation, mediastinal shift, and cardiopulmonary compromise may occur A more unusual presentation in which the cyst exists within the airway wall may present with signs and symptoms similar to an airway foreign body; if such a cyst is proximal and enlarges rapidly due to mucus production, inflammation, or hemorrhage, acute airway obstruction may occur This condition may be hard to diagnose with routine imaging studies as there is no predominant mass Bronchoscopy may be the only means for diagnosis and treatment of this situation For the majority of patients, however, symptoms are less severe and less acute; presentation is usually as an older infant or child with complaints of infection or dysphagia Symptoms of cough, wheezing, fever, or hemoptysis prompt chest roentgenogram, which may demonstrate an unusual opacity or lucency, postobstructive emphysematous changes, or air–fluid level within the cyst (Figure 13-3) A chest radiograph that suggests a mass should be followed by CT scan to verify and localize the mass, determine its resectability, and to eliminate any nonoperative diagnoses such as pneumonias, simple lung abscesses, and certain lymphangiectasis CT scan should demonstrate a cystic structure with a nonenhancing wall; it may have an air–fluid level (Figures 13-4 and 13-5) A finding of segmental emphysematous change may warrant bronchoscopy to rule out an airway foreign body (especially in the age group in which aspiration is common) or extrinsic airway compression It may be difficult to differentiate between bronchogenic cyst and pulmonary abscess, but an indolent clinical course coupled with persistent radiograph findings in the face of abatement of clinical symptoms suggests bronchogenic cyst over infectious etiologies Those with persistent evidence of systemic infection and pulmonary symptoms may have infection alone or in combination with underlying bronchogenic cysts and would likely benefit from resection with respect to either the infection or cyst Patients who present with dysphagia should undergo esophagogram, which will sometimes reveal evidence of FIGURE 13-3 Bronchogenic cyst: Plain radiograph demonstrating a large right-sided bronchogenic cyst FIGURE 13-4 Bronchogenic cyst: Computed tomography scan with cm right-sided nonenhancing mass representing a paratracheal bronchogenic cyst Surgical Management of Congenital Lesions of the Lung / 167 difficult to differentiate a bronchogenic cyst from other congenital cystic malformations These other diagnoses may have associated anomalies, which need to be investigated and addressed prior to cyst excision Cysts should be followed by ultrasound prenatally and if a large cyst causes in utero compromise from mediastinal displacement or hydrops, in utero decompression can be achieved via aspiration or thoracoamniotic shunt placement.7 These cysts not routinely expand rapidly in utero, so ultrasound monitoring does not have to be done as frequently as for lesions such as CCAM or pleural effusions There is some debate, but most pediatric surgeons believe for several reasons that asymptomatic children should undergo resection of their bronchogenic cyst in the absence of prohibitive medical comorbidities and risk factors that may rarely warrant observation Cysts increase in size over time due to mucous production and therefore will ultimately become symptomatic; resection before infectious complications develop is preferable, especially since this may decrease inflammation and make resection technically easier There is also a malignant potential Both rhabdomyosarcoma and adenocarcinoma have developed within bronchogenic cysts.8–10 Although malignancy is a rare occurrence, the natural history is difficult to evaluate as most lesions are resected in children A welldifferentiated papillary adenocarcinoma in a retroperitoneal bronchogenic cyst was found at laparotomy for abdominal pain in a 55-year-old woman.8 Therefore, in asymptomatic adults, because of the malignant potential and presence of the lesion since birth, bronchogenic cysts should be addressed at the time of their discovery The advent of sophisticated techniques provides an avenue for surveillance and in some situations may justify conservative treatment of adults with small, stable, asymptomatic cysts that are not prone to connection with the tracheobronchial tree.11 Cyst fluid and sometimes cyst wall can be sampled via percutaneous or transbronchial needle aspiration Recurrence after aspiration, malignant cells, cyst growth, symptoms, an air–fluid level, or an intraparenchymal lesion warrants complete surgical resection When evaluating the benefits of resection in adults, the patient’s projected longevity and comorbid medical issues should be assessed in conjunction with the proposed surgical procedure (less invasive bronchoscopy or thoracoscopy versus mediansternotomy or thoracotomy) and the probability of developing a malignancy vascular supply (Figure 13-6) Several theories exist regarding their development Sequestrations could result from traction applied to developing lung tissue by elongating systemic arterial channels, which would explain the ultimate anatomical relationship between the pulmonary tissue and systemic blood supply Sequestrations may also represent other congenital lung anomalies such as CCAMs or bronchogenic cysts that develop an aberrant blood supply Alternatively, sequestrations may develop from accessory lung buds, which have systemic blood supply separate from the normal pulmonary vasculature The arterial supply to the sequestration usually emanates from below the diaphragm and is almost always a branch from the abdominal aorta Sequestrations that develop before the completion of visceral pleura formation exist within normal lung parenchyma and are called intralobar; extralobar sequestrations develop after pleura formation of the normal lung and have their own pleura (Figure 13-7) Pulmonary sequestration accounts for about 30% of bronchopulmonary-foregut anomalies There is no strong gender preference, although some reports describe a male preference (1.5:1) No known causative genetic defect exists, although at least one report involves two male siblings with sequestrations.12 Associated congenital anomalies occur and with higher frequency in extralobar sequestration; as the bronchopulmonary tree and foregut are closely linked in development, many associated anomalies are other congenital lung bud or upper gastrointestinal defects Sequestration may be found in conjunction with bronchogenic cysts, esophageal cysts, CCAM, and tracheoesophageal fistulas Sequestrations are most often unilobar and involve the lower lobes but can involve an entire lung or rarely both lungs Classification into intralobar and extralobar subtypes is not only useful from a pathologic standpoint, but also has clinical application, as each variety has different Pulmonary Sequestration Pulmonary sequestrations were first described by Pryce in 1946 They are composed of nonfunctional embryonic lung with absent or abnormal communication to the tracheobronchial tree and a predominantly systemic FIGURE 13-6 Pulmonary sequestration: 50ϫ magnification; hematoxylin/eosin stain Surgical Management of Congenital Lesions of the Lung / 169 of sequestrations with gastrointestinal communication reported that 43% were evident by days of life, 30% within the first year, 17% by age 18 years, and 10% as adults.17 Most commonly, however, children present by age 10 years with chronic cough, recurrent pneumonia, or its complications Pulmonary abscess can cause erosion of vessels, and because of their systemic arterial pressure, hemoptysis or hemothorax can be massive; even fatal hemoptysis has been reported Sequestrations are discovered incidentally in about 15% of cases on imaging for unrelated issues or during surgery to correct other congenital defects such as diaphragmatic hernia.15 Diagnostic imaging should start with plain chest radiograph, which may demonstrate consolidation (since extralobar sequestrations are not connected to the tracheobronchial tree and are not aerated) or mass effect; sometimes there will be cysts or evidence of lung abscess (Figure 13-8) The diagnosis of sequestration can be confirmed by documenting the aberrant blood supply with ultrasound, MRI, or CT (Figures 13-9 and 13-10) It is important to image below the diaphragm since most arterial supply is from the abdominal aorta Invasive studies such as aortography are unnecessary; even MRI and CT are not routinely necessary if plain film and ultrasound provide enough evidence of a thoracic mass with infradiaphragmatic aortic blood supply Ultrasound is noninvasive and excellent for vascular evaluation; it also does not require the same duration and degree of stillness as magnetic resonance scanning In young children, advanced imaging may require general anesthesia as well as contrast material; therefore, more complex tests should be used only if additional information is needed FIGURE 13-8 Pulmonary sequestration: Plain radiograph with hyperlucent area demonstrating a right-sided pulmonary sequestration FIGURE 13-9 Pulmonary sequestration: A, Ultrasound identifying the aberrant systemic blood supply originating from the aorta and entering the mass B, Duplex demonstrates the arterial waveform in this vessel Surgical Management of Congenital Lesions of the Lung / 171 without esophageal atresia These usually have systemic arterial supply but may also have atretic pulmonary blood supply Venous drainage may be pulmonary, azygous, or portal These cases should undergo resection In the cases where lobar or segmental airways connect to the esophagus, the corresponding airway is absent in conjunction with the tracheobronchial tree.17 Type IV sequestrations (5%) are described as intralobar sequestrations in which part of the tracheobronchial tree connects to the esophagus These have systemic blood supply and they should be resected The outcome of children with pulmonary sequestration is excellent if it is isolated or if the prognosis for any associated congenital conditions is good The survival for surgical resection has reached almost 100%, even for pneumonectomy; the main complications are postoperative pulmonary infection or leak from gastrointestinal communication Improvements in imaging and understanding of the vascular abnormalities associated with sequestrations make exsanguination from an aberrant artery preventable Reflux is also reported to occur frequently in those who have had sequestrations with connection to the gastrointestinal tract at the gastroesophageal junction Complications occur infrequently and are treatable The major morbidity comes from pulmonary hypoplasia or associated congenital anomalies, especially cardiac defects or diaphragmatic hernia associated pulmonary hypoplasia A 75% mortality is reported in the 15% of sequestrations with associated conditions.20 Congenital Lobar Emphysema CLE refers to a hyperinflated segment of histologically normal lung It occurs rarely and is more common in male than female babies (3:1) In 20% of patients, associated cardiac, rib, and renal anomalies exist Most often, a single, upper lobe is affected, specifically the left upper lobe; multiple lobes can be involved and 20% are bilateral Lobar emphysema is caused by expiratory collapse of the airway and air trapping Air can also enter the parenchyma through pores of Kohn with adjacent lung and thereby keep an area hyperinflated even if the airway is obstructed on inspiration Constant hyperinflation leads to septal destruction and large emphysematous air sacs Physiologically, CLE causes symptoms by displacing normal lung, creating mediastinal shift, and decreasing venous return CLE can be due to not only intrinsic obstruction (foreign body, mucus, or endobronchial lesion) but also extrinsic causes of compression such as masses, enlarged cardiac chambers (15%), lymphadenopathy, or vascular rings, and these etiologies should be entertained during differential diagnosis espe- cially in a patient presenting after the newborn period Intrinsic causes, which are more likely to present in infancy, include hypoplasia (Figure 13-11) of airway cartilage (documented in about 35% but perhaps as prevalent as 70%), excess bronchial mucosa, mucous plugging, airway torsion, alveolar fibrosis, alveolar septal destruction, and polyalveolar lobes Polyalveolar lobes, which may account for up to 30% of congenital hyperinflation syndromes, demonstrate increased numbers of alveoli that accumulate air.21 In up to 50% of cases, the exact cause of hyperinflation is not identified The timing and acuity of presentation depends on the degree of hyperinflation, rate at which it develops, displacement of normal lung, and mediastinal shift Presentation can be dramatic, for example, with expiratory obstruction causing a sudden increase in hyperinflation with mediastinal shift and cardiopulmonary collapse This is most characteristic of CLE from airway hypoplasia with collapse or intrinsic airway obstruction as an etiology With parenchymal causes of emphysema such as septal destruction or polyalveolar lobes, hyperinflation is from gradual accumulation; therefore, sudden expansion due to expiratory insufficiency does not lead to sudden mediastinal shift phenomena If the area involved is large, infants may present in the perinatal period when their lungs become aerated and hyperinflation develops Respiratory distress can be severe if the hyperinflation is sudden, causing mediastinal shift, which exacerbates instability by diminishing the expansion of the contralateral lung and limiting venous return and cardiac output Infants usually present with respiratory distress or even cyanotic spells within to months of age Children who present in the newborn period are more likely to have symptoms that worsen quickly and FIGURE 13-11 Congenital lobar emphysema (CLE): Pathology specimen of airway from surgically resected CLE The airway is collapsed and cartilage, which should have a uniform circumferential distribution, has a sparse and irregular pattern 50ϫ magnification; hematoxylin/eosin stain 172 / Advanced Therapy in Thoracic Surgery require surgery early on Fifty percent of babies that undergo resection for CLE are diagnosed within several days of life; the other half may not present for months Less symptomatic infants and children have a more insidious presentation manifested by failure to thrive, mild tachypnea, unequal breath sounds, shifted position of maximal cardiac impulse, expiratory wheezing, hyperresonance, or tracheal deviation The presentation can take several months while the degree of collapse reaches a point at which air trapping occurs Crying spells can significantly exacerbate hyperinflation and mediastinal shift Prenatal diagnosis is rare because the lungs are not aerated; therefore, the diagnosis is usually made with plain chest film in the newborn period or upon presentation with clinical signs Chest radiograph will demonstrate a hyperlucent area, surrounding atelectasis, ipsilateral diaphragmatic flattening, and possibly mediastinal and tracheal deviation (Figure 13-12) The lobes are involved in the following distribution: left upper lobe 40%, right middle lobe 35%, right upper lobe 20%, and bilateral 1% 2 Differentiation via radiograph from primary cysts or tension pneumothorax may be difficult but one will see faint outlines of pulmonary vasculature FIGURE 13-12 Congenital lobar emphysema (CLE): Plain radiograph showing a left-sided CLE with hyperinflation, mediastinal shift, and displacement of the cardiac silhouette towards the right hemithorax Lung markings are present throughout the left hemithorax and no collapsed lung edge is evident which differentiates this from a tension pneumothorax within the affected CLE Additional imaging is usually unnecessary to diagnose CLE but may be helpful in finding the etiology or differentiating CLE from atypical appearing CCAM or pneumothorax if diagnosis is unclear on plain film Extrinsic causes of airway obstruction such as a thoracic mass or vascular ring should be investigated using MRI or CT, especially in older patients in whom these etiologies are more likely (Figure 13-13) Bronchoscopy should be performed if suspicion of a foreign body or endobronchial lesion is high Echocardiography to identify associated cardiac conditions and ultrasound to look for renal anomalies will be positive in 20% Although not routinely necessar y, a ventilation–perfusion scan, if performed, will show delayed uptake and washout of xenon and decreased blood flow in the emphysematous portion Pulmonary function tests (they would show slightly decreased flow) are not necessary for preoperative workup of isolated CLE since the remainder of the lung has normal function There is no associated lung hypoplasia because the hyperinflation develops after delivery and does not cause in utero compression of the developing lung Occasionally, on CT or ventilation–perfusion scan, additional areas of hyperinflation become evident; these, however, can be seen and addressed at the time of thoracotomy The treatment strategy for CLE is resection of the affected lobe (Figure 13-14) One must also eliminate any possible extrinsic or intrinsic cause for obstruction and hyperinflation that can masquerade as CLE; if this leads to resolution of air trapping, the diagnosis was not primar y CLE and lobar resection be avoided Occasionally, a mass or vascular ring causing compression will be apparent as the cause of bronchiolar collapse and can be removed In addition, rarely, things causing endobronchial obstruction may be amenable to endoscopic removal For this reason, bronchoscopy should be performed prior to resection to identify any potentially treatable lesions Since at least one-half the cases of CLE have no known etiology and many others have hypoplastic airway cartilage as a cause, sparing a lobe is rarely possible Complete resection of the lobe and any additional segments involved is curative and should be prompt Some feel that babies with mediastinal shift regardless of symptoms should be kept under medical observation until surgical correction If there is evidence of longstanding stable disease without symptoms (delayed referral perhaps), these children have low likelihood of sudden decompensation and can remain at home until surgery, which should occur within the next couple of weeks Symptoms, unpredictable course, or unpredictable compliance are indications for admission and surgery as soon as any necessary preoperative treatment is completed Evaluation for associated cardiac Surgical Management of Congenital Lesions of the Lung / 175 cells; occasional elements of skeletal muscle can be found suggesting a hamartomatous condition The most commonly used classification for CCAM divides the malformations into three types based on the cyst characteristics.24 Type I is macrocystic disease and represents 60 to 70% of CCAM; 50% of type I lesions occur on the left, 35% occur on the right, and between and 14% are bilateral.25,26 This type of CCAM is composed of single or multiple cysts (usually between one and four) that are more than cm The cyst walls may include smooth muscle cells and are lined with ciliated pseudostratified columnar epithelium Type II CCAM, which occurs 20% of the time, is commonly called mixed disease and contains adenomatoid material mixed with small and medium-sized cysts of about cm In this case, alveolar type tissue is found among the cysts that are lined with ciliated cuboidal or columnar epithelium Congenital anomalies (which occur in up to 70% of type II CCAM) and prematurity (up to 75%) 23 are almost exclusively associated with this type of CCAM, accounting for its poorest prognosis Type III disease occurs 10% of the time and is referred to as microcystic CCAM This subtype presents more often in boys Its appearance on ultrasound is echogenic due to solid components, and this firm mass tends to involve an entire lobe It is composed of mainly adenomatoid bronchioalveolar-like tissue with minimal amounts of small cysts but there is no normal lung Some authors classify CCAM into two types.27 The macrocystic type has single or multiple fluid filled cysts greater than mm, and the microcystic type has solid components in combination with cysts less that mm As with other chest occupying lesions that lead to compression or lung hypoplasia, the most common symptom is respiratory distress In situations where FIGURE 13-15 Congenital cystic adenomatoid malformation: Dysplastic overgrown bronchioles of congenital cystic adenomatoid malformation 12.5ϫ magnification; hematoxylin/eosin stain mediastinal displacement has occurred, decreased venous return can lead to cardiac collapse and further diminished function of the contralateral lung In utero, this mass effect leads to lung hypoplasia and to hydrops; compression of the esophagus can also lead to polyhydramnios The severity of symptoms depends on the degree of hypoplasia In the newborn period severe respiratory and cardiovascular symptoms develop from lung hypoplasia and mediastinal shift In older children, recurrent infection is the most common symptom With longstanding disease, bronchioalveolar cancer and rhabdosarcoma have been reported 28 Some infants with prenatal diagnosis are asymptomatic at delivery and may even have radiologic regression or disappearance of the mass Most have varying degrees of respiratory symptoms at birth Most diagnoses are made before age months, and 60% are made within the first month Onehalf of CCAMs will present in the newborn period either with symptoms or as a result of prenatal screening; also, type II CCAM babies will often present with prematurity The 50% of infants that present after the newborn period fare much better with their milder CCAMs These children may not have a lesion that causes respiratory distress at rest, but during times of stress, such as with upper respiratory infections, increased activity, or sometimes feeding, they will become symptomatic At these times they may present with tachypnea or wheezing, and on auscultation may have decreased breath sounds over the affected lobe Infection can also occur with cough and fever, and a pattern of recurrent infections usually leads to chest roentgenogram Failure to thrive is another presentation prompting a search for pulmonary afflictions Sometimes the diagnosis is made incidentally as patients undergo imaging for other reasons The chest radiograph may reveal the characteristic cystic mass or an infiltrate It may take recurrent infiltrates in the same lobe to trigger studies such as CT to diagnose an underlying CCAM CCAM is the most commonly diagnosed congenital lung anomaly because its cystic appearance makes it readily apparent on prenatal ultrasound Prenatal diagnosis is therefore common and CCAMs are detectable on ultrasound by 12 weeks’ gestation Ultrasound typically demonstrates a macrocystic, microcystic, or solid lesion and may show displacement of the heart or diaphragm Polyhydramnios is seen in 65% of cases and is ominous Hydrops and ascites can be seen in up to 45% The diagnosis in babies after delivery is usually discovered after the infant has plain chest film for respiratory distress or unequal breath sounds; up to 15% of babies are diagnosed after age months The chest radiograph will have a mass that may appear typically macrocystic or may appear solid in nature if there is microcystic disease 176 / Advanced Therapy in Thoracic Surgery (Figure 13-16) The appearance of CCAM on plain chest film may be deceptive; a frequent mimic of CCAM is congenital diaphragmatic hernia, which has a very different treatment algorithm Placement and visualization of a nasogastric tube in the chest differentiates the two thoracic anomalies Infants with prenatal diagnosis of CCAM should have confirmation of its persistence, as there are reports that some CCAMs seen on prenatal sonography are no longer apparent on postnatal imaging Examination with ultrasound or CT helps to assess the amount of involved lung and to differentiate CCAM from mediastinal and other primary lung lesions such as sequestration, bronchogenic cyst, diaphragmatic hernia, or lymphangiectasis In the newborn period, an ultrasound to confirm that the mass is a parenchymal CCAM may be the only necessary study (Figure 13-17) It will also indicate whether the lesion is microcystic or macrocystic (Figure 13-18) Although uncommon, vascular abnormalities can occur with cystic adenomatoid malformations and one should look for this on ultrasound As the age at presentation increases, chest CT becomes more important and effective at deciphering the growing differential of infectious etiologies, malignancies, and foreign bodies Many surgeons prefer CT imaging FIGURE 13-16 Congenital cystic adenomatoid malformation (CCAM): Plain radiograph demonstrating multiple cysts in a left-sided CCAM There is minimal mediastinal displacement Multiple cysts can appear similar to a congenital diaphragmatic hernia FIGURE 13-17 Congenital cystic adenomatoid malformation, multicystic: Ultrasound Bottom ridge represents the vertebral column The left side of the image is cephalad FIGURE 13-18 Congenital cystic adenomatoid malformation (CCAM): Ultrasound The vertebral column can be seen traversing the image and a large hypoechoic area represents the normal lung The two small hypoechoic areas are the CCAM, and the echodense area bordering the left side of the image is the liver Surgical Management of Congenital Lesions of the Lung / 177 because of the axial images and their own familiarity with interpreting this test (Figure 13-19) The treatment for CCAM even in asymptomatic patients is surgical resection before the development of infectious or malignant complications (Figures 13-20 and 13-21) Babies with prenatal diagnoses should be cared for at a tertiary medical center and followed with ultrasound every weeks to watch for the development of hydrops Hydrops is the most ominous sign of poor outcome, and affected infants have severe lung hypoplasia; in the past almost all babies with hydrops died (up to 70% in utero and 90% that were delivered) Hydrops also precipitates preeclampsia, and premature delivery further FIGURE 13-19 Congenital cystic adenomatoid malformation, leftsided: Computed tomography scan FIGURE 13-20 Congenital cystic adenomatoid malformation: Intraoperative photo FIGURE 13-21 Congenital cystic adenomatoid malformation: Specimen exacerbates the situation with lung disease of prematurity Fetal echocardiography should be performed to identify any concomitant cardiac defects and help provide a prognosis Today, parents have the following options: postnatal care, fetal intervention, or termination for moribund cases In considering fetal procedures and their risks, it is important to know that even in cases with hydrops, regression of the CCAM can occur in up to 15% of cases Also, with modern resuscitation, ventilatory techniques, prepartum steroids, and extra corporeal membrane oxygenation (ECMO), fetuses without hydrops or other lethal anomalies have almost 100% survival and fetal intervention cannot be routinely recommended For this reason, consideration of fetal intervention can effectively be restricted to those with early development of hydrops Even before the advent of open fetal surgery and fetoscopic techniques, fetal intervention has been available via cyst aspiration and thoracoamniotic shunting and these techniques have been reported as early as 1988.29 Cyst aspiration requires repeat drainage as the thoracic cavity rapidly fills with fluid to occupy the space created by the cyst aspiration27; this is therefore not a good long-term solution Thoracoamniotic shunting has been successful in a small number of hydropic patients with macrocystic disease who have a dominant cyst amenable to drainage; however, shunt dislodgement or occlusion can be problematic In a report of thoracoamniotic shunt use in six fetuses with hydrops and macroscopic disease with a predominant large cyst, five of six patients survived and the one death was due to premature rupture of membranes followed by precipitous delivery This underscores the point that even seemingly less invasive fetal procedures disturb the intrauterine environment and are not without significant risk of premature delivery 30 Fetal thoracotomy with surgical resection of the CCAM continues to evolve A review of 134 fetuses with CCAM over a 15-year period confirms the principle that fetal procedures be limited to those with hydrops Fourteen of the fetuses underwent 178 / Advanced Therapy in Thoracic Surgery elective abortion and the remaining 120 were analyzed One hundred and one fetuses were managed expectantly with delivery and any surgical intervention done postnatally; every hydropic fetus died or expired shortly after delivery, and all 76 nonhydrops babies survived, although required ECMO support This further verifies that nonhydrops fetuses have good prognosis, but hydrops is lethal without prenatal intervention In the same study, 19 fetuses underwent fetal procedures; fetuses were discussed above regarding thoracoamniotic shunting The remaining 13 fetuses underwent thoracotomy and lobectomy between gestational weeks 21 and 29 done through a hysterotomy Survival of the hydrops fetuses after open fetal surgery was 62% and hydrops resolved within weeks, mediastinal shift was gone after weeks, and there was evidence of substantial lung growth All of 13 deaths were attributable to inability to maintain the pregnancy either during the procedure or in the perioperative period.27 Preterm labor following fetal surgery and pulmonary hypoplasia continue to be responsible for the morbidity and mortality in this technique These data demonstrate that without hydrops the risk of fetal intervention outweighs the benefit and these infants should be treated after delivery with an attempt to carry the fetus to term Other authors have confirmed these data.30–33 In cases of the “mirror” syndrome of maternal hyperdynamic state or after placentomegaly develops, there were no survivors of fetal interventions due to inability to sustain the pregnancies Therefore, fetal intervention is not indicated and in these situations or in the face of concomitant lethal anomalies, some families have opted for termination If hydrops develops after 32 weeks or if the biophysical profile of an otherwise viable fetus deteriorates (greater than 24 weeks’ gestation without other lethal conditions) early delivery is indicated Early delivery occurs in up to 50% of CCAMs and is often the result of preterm labor that cannot be treated Steroids should be given to enhance lung maturity if the fetus is less than 32 weeks’ gestation The majority of these preterm infants will require immediate intubation and resuscitation Severely premature infants (less than 29 weeks) will have not only CCAM-related lung hypoplasia, but also lung disease of prematurity to add to their respiratory compromise, and a significant number of these infants will be dependent on such high ventilator settings to sustain marginal respiratory parameters that they will not tolerate thoracotomy If there is any indication that the CCAM and its mass effect on respiratory mechanics are the predominant cause of respiratory failure, resection should be undertaken immediately and the condition may improve; however, this is not always clear and if the pulmonary insufficiency is mostly related to lung hypoplasia or prematurity, resection will not bring swift improvement, and positioning or retraction necessary for surgery may be more than the baby can tolerate In addition, as with in utero CCAMs, these lesions may decrease in size after birth In very premature, low birth weight babies whose primary lung disease or pulmonary hypertension is the main cause of respiratory failure, resection should be postponed until the infant is fit for thoracotomy under general anesthesia from a respiratory standpoint In some premature infants clinical reasoning becomes somewhat circular, with resection precluded due to lung disease of prematurity and slow improvement in pulmonary status in part potentially due to the remaining mass There are some maneuvers to improve respiratory mechanics while waiting for surgery Placing the child with the symptomatic side down may decrease distension on the affected side by limiting aeration and jet or high-frequency ventilation minimizes hyperinflation and decreases traumatic high airway pressures in premature lungs Associated life-threatening conditions, especially cardiac conditions, must be addressed, and the congestive cardiac failure must be aggressively treated with inotropes and diuresis Unfortunately some babies have such significant hypoplasia that they not improve ECMO can be used to support infants with severe pulmonary hypoplasia, and surgical resection of the CCAM can even be performed while on ECMO The infants must weigh more than kg to utilize ECMO and must be fully heparinized Inability to wean from bypass by approximately weeks indicates pulmonary hypoplasia so severe that the infant is unsalvageable and bypass support is withdrawn Term or near-term infants with a prenatal diagnosis of CCAM should undergo chest radiograph because there may be regression or even disappearance of the mass If the mass is not evident on postnatal plain film, ultrasound or CT should be done; if there is still no evidence of a mass, patients are followed with serial ultrasound Evidence on future exams of a mass warrants excision Those with a clear lesion on imaging but mild or absent symptoms can undergo resection electively if no mediastinal shift develops over the first 48 hours Mediastinal shift, tachypnea, oxygen requirement, or ventilator dependence should prompt resection as soon as preoperative preparation can be completed and more urgently if symptoms dictate Cardiac lesions should be anticipated and sought with echocardiogram, especially with type II lesions, in which associated congenital anomalies are common Children and adults with asymptomatic or incidentally noted CCAM should undergo resection electively not only because there is documented risk of malignancy,28 but also because infectious complications that would likely develop can thereby be avoided Technically, resection of CCAM usually requires lobectomy, but in up Surgical Management of Congenital Lesions of the Lung / 179 to 15% pneumonectomy may be required This is more common in type III CCAM as the more diffuse and microscopic nature may make it difficult to separate from surrounding normal lung and because type III disease has a propensity to involve the entire lung Very rarely, segmental resection of the CCAM is possible along with its tributary tracheobronchial tree The airways and vessels follow a normal anatomic configuration, although there may be additional systemic arterial supply similar to that in sequestration Significant anesthetic difficulties regarding airway deviation or hyperinflation are rare and mild compared with CLE, but they must be anticipated Pulmonary hypoplasia and lung disease of prematurity are the most important factors in determining outcome There is a tremendous range in survival (11–95%)25 and fetal hydrops portends the poorest prognosis Uncomplicated macrocystic (type I) CCAM has survival rates of 70 to 95% Types II and III CCAMs have the poorest prognosis (< 50% survival23) due to frequent associated cardiac defects, severe lung hypoplasia, the incidence of prematurity in type II lesions, and the increased incidence of diffuse lung involvement in type III In addition, type II CCAM is more frequently associated with in utero hydrops and polyhydramnios, which both independently worsen prognosis Medical comorbidities not only contribute independent physiological complications but also increase anesthetic risk and sometimes postpone surgical resection Fetal hydrops is seen in up to 45% of fetuses with CCAM and is a grave prognostic sign; in 68% of these there will be fetal demise, and of the remaining 32% that are delivered, 89% succumb, making the outcome with hydrops almost universally fatal Polyhydramnios itself is associated with 50% mortality.25 Of all CCAMs diagnosed in the prenatal or newborn period, up to 60% will die because this includes the significant number of cases with fetal hydrops or polyhydramnios with in utero death and those with associated anomalies that die However, of the infants that survive to delivery, since the remaining group has very low incidence of hydrops and is comprised mainly of the favorable CCAM subtypes, survival of 80 to 100% has been reported 4,34 Infants without hydrops, associated severe prematurity, or associated anomalies have a survival of up to 90% Children who have delayed presentation with infection fare the best and have essentially 100% survival The advent of fetal surgery shows promise in improving the survival for cases of fetal hydrops in which demise was previously almost certain, and the survival for fetuses with hydrops may be as high as 74% with fetal intervention.27 Unfortunately, intraoperative contractions, maternal hyperdynamic state, and preterm delivery still lead to fetal demise up to 25% of the time.27 Cases without evidence of hydrops have a more favorable prognosis, and regression of the lesion occurs in up to 15%; all nonhydropic fetuses analyzed in the literature survived with postnatal treatment, and fetal surgery cannot be routinely recommended for these cases at this point The ability to predict more accurately which fetuses will have significant symptoms after birth and, more importantly, development of techniques to prevent surgically induced preterm delivery may expand the indications for this modality Pleural Effusion Fluid in the pleural space occurs in in 10,000 newborns and has a male predilection (2:1) There are no known associated teratogens but effusions have been associated with a variety of other anomalies and genetic syndromes including Down syndrome, Turner syndrome, Caffey hyperostosis, Opitz-Frias syndrome, congenital pulmonary lymphangiectasis, esophageal atresia, and extralobar sequestration.35,36 Congenital effusions may be primary (chyle) or secondary (nonimmune hydrops or hypoalbuminemia), and most are found on the right side although effusions can occasionally be bilateral Primary chylous effusions are of unclear etiology, although some derangement in either increased production or decreased absorption must be involved Reduced lymphatic drainage may come from inadequate communication between pulmonary lymphatic channels and their main thoracic drainage; this may be a result of congenital absence, birth injury, or obstructing mediastinal mass Lymphatic abnormalities are not usually found in other organs with the exception of rare associated lymphangiectasis Congenital effusions can become very large and cause ipsilateral lung hypoplasia due to in utero pulmonary displacement Situations in which the effusion causes mediastinal shift may lead to hydrops by impairing venous return and cardiac output Many infants will have prenatal diagnosis and will have respiratory distress at birth Most other infants present within the first several days of life with varying degrees of respiratory distress Infants with mild symptoms present with decreased breath sounds on the affected side, and plain chest film quickly identifies the effusion as an opacified hemithorax and caudad displacement of the ipsilateral diaphragm Primary pleural effusions may demonstrate downward displacement of the ipsilateral diaphragm but secondary effusions will not and this helps to distinguish between the two The appearance of the pleural fluid may by deceiving, as chylous effusions may appear clear if the patient has no enteral fat intake A cell count demonstrating more than 60% lymphocytes supports chylothorax; triglycerides are usually greater than 200 mg/dL, Thoracic Outlet Syndrome / 201 subperiosteal plane, no damage occurs to the first thoracic nerve root, which lies immediately under the rib Complete removal of the neck and head of the first rib is achieved by a long double-action pituitary rongeur The eighth cervical and first thoracic nerve roots can be visualized clearly at this point If a cervical rib is present, it is removed at this time and the seventh cervical nerve root can be observed Only the subcutaneous tissues and skin require closure, because no large muscles have been divided Intermittent firm traction is required for exposure, and no evidence of brachial plexus stretching or neuritis has been observed when this technique is used The patient is encouraged to use the arm normally and can be discharged from the hospital between and days after the surgical procedure.3 It is preferable to remove the entire first rib, including its head and neck, to avoid future irritation of the plexus, because a residual portion may cause recurrence of symptoms The periosteum should be fragmented and destroyed to prevent callus formation and “regeneration” of the rib Removal of incompletely resected or “regenerated” rib can best be accomplished through the posterior approach.18 For lysis of adhesions of the brachial plexus in symptomatic patients with decreased UNCV following previous complete resection of the first rib, the anterior supraclavicular approach is used Postoperative pain may become a significant issue in patients with a first rib resection To overcome this problem we have been using a C8-T1 paravertebral block placed by the anesthesiologist at the end of the procedure A comparative study demonstrated a significant decrease in postoperative pain scores when a patient received a paravertebral block versus no block.19 Recently, Wolf has described a total thorascopic approach for removal of the first rib in thoracic outlet syndrome.20 This may also reduce postoperative pain However, outcomes regarding complete removal or regeneration of the rib are yet to be determined Results The clinical results of first rib resections in properly selected patients are good in 85%, fair in 10%, and poor in 5% A good result is indicated by complete relief of symptoms, a fair result by improvement with some residual or recurrent mild symptoms, and a poor result by no change from the preoperative status Uniform improvement of symptoms is usually obtained in patients with primarily vascular compression In patients with predominantly nerve compression, however, two groups with different rates of improvement are observed The first group includes patients with the classic manifestations of ulnar neuralgia and elicitation of pulse diminution, in whom an average preoperative UNCV is reduced to 53 m/s Ninety-five percent of patients in this group are improved by first rib resection In the second group are patients with atypical pain distribution, who may or may not have shown pulse changes by compression tests, and in whom the average preoperative ulnar nerve conduction velocity was only reduced to 60 m/s Surgical intervention is carried out in such patients as a therapeutic trial after prolonged conservative therapy has failed Although, many patients in the second group improve, the fair and poor results all occur in these patients The UNCV and clinical status are highly correlated Patients with good postoperative results have a preoperative average UNCV of 51 m/s and show return to a normal average of 72 m/s after operation In those who have fair results, the preoperative UNCV averages 60 m/s and increases to an average of only 63 m/s after operation In the poor result group, no appreciable change occurs in the postoperative from the preoperative values; in fact, the average conduction time was only 58 m/s.11 No hospital mortality has been directly related to this procedure Postoperative morbidity after the transaxillary approach includes clinically inconsequential pneumothorax in 15%, hematoma in 1%, and infection in 1% Paget-Schroetter Syndrome “Effort” thrombosis of the axillary-subclavian vein— Paget-Schroetter syndrome—usually occurs as a result of unusual or excessive use of the arm in addition to the presence of one or more compressive elements in the thoracic outlet Sir James Paget in 1875 in London and von Schroetter in 1884 in Vienna described this syndrome of thrombosis of the axillary-subclavian vein, which bears their names.21,22 The word “effort” was added to thrombosis because of the frequent association with exertion producing either direct or indirect compression of the vein The thrombosis is caused by trauma or unusual occupations requiring repetitive muscular activity as has been observed in professional athletes, linotype operators, painters, and beauticians Cold and traumatic factors such as carrying skis over the shoulder tend to increase the proclivity for thrombosis Elements of increased thrombogenicity also increase the incidence of this problem and exacerbate its symptoms on a longterm basis For years, patients with effort thrombosis were treated with anticoagulants and conservative exercises; if recurrent symptoms developed when they returned to work, they were considered candidates for first rib resection 202 / Advanced Therapy in Thoracic Surgery Use of thrombolytic agents with early surgical decompression of the neurovascular compression has reduced morbidity, such as postphlebitic syndrome and the necessity for thrombectomy Evaluation of 512 patients with Paget-Schroetter syndrome (effort thrombosis of the axillary-subclavian vein) over 35 years emphasizes the necessity of (1) an accurate diagnosis, (2) expeditious thrombolytic therapy, and (3) prompt first rib resection • Group I (35 patients) was initially treated with anticoagulants only Twenty-one developed recurring symptoms after returning to work, requiring transaxillary resection of the first rib Thrombectomy was necessary in eight • Group II (36 patients) was treated with thrombolytic agents initially, followed promptly by first rib resection Thrombectomy was necessary in only four Thirty-one of these patients (95%) showed improvement and returned to work with no further complication • Group III (384 patients) was evaluated within the first weeks following thrombosis and had excellent results using the group II protocol No thrombectomy was required, and all veins were open at surgery or recanalized within months • Group IV (57 patients) was seen after weeks from venous occlusion Intravascular stents had been inserted in 22 patients (In only 50% of these was it possible to decrease the amount of clot with thrombolytic infusion, and all veins remained occluded.) After first rib resection, 32 patients recanalized spontaneously and became asymptotic Of the 25 patients with persistent occlusion, developed severe postphlebitic syndrome, had mild symptoms, required “Roto-Rooter” destruction of the clot with “relief ” of symptoms, and 12 developed adequate collateral circulation (Bypass grafts were performed in patients occluded before our evaluation.) No deaths were reported in this series.3,23,24 Adam and DeWeese reported long-term results in patients treated conservatively with elevation and Coumadin.25 They noted a 12% incidence of pulmonary embolism Development of occasional venous distention occurred in 18%, and late residual arm symptoms of swelling, pain, and superficial thrombophlebitis were noted in 68% of the patients—deep venous thrombosis with postphlebitic syndrome One patient had phlegmasia cerulea dolens These findings substantiate our observations in group I that a more aggressive operative approach after thrombolytic therapy is indicated, particularly for younger patients in precipitating occupations One advantage of urokinase over streptokinase is the direct action of urokinase on the thrombosis distal to the catheter, producing a local thrombolytic effect Streptokinase produces a systemic effect involving the alteration of serum plasminogen and increasing potential complications Heparin is given postoperatively until the catheter is removed A decrease in the need for thrombectomy after use of the thrombolytic agent followed by aggressive surgical intervention is another advantage, as some of the long-term disability is related to morbidity from thrombectomy as well as recurrent thrombosis The natural history of Paget-Schroetter syndrome suggests moderate morbidity with conservative treatment alone Bypass with vein or other conduits have limited application Causes other than thoracic outlet syndrome must be treated individually using the basic principles mentioned Intermittent obstruction of the subclavian vein can lead to thrombosis, and decompression should be used prophylactically Recurrent Thoracic Outlet Syndrome Removal of the first rib offers relief of symptoms in patients with thoracic outlet syndrome not improved by physiotherapy Ten percent of the surgically treated patients develop variable degrees of shoulder, arm, and hand pain and paresthesias that are usually mild and short-lasting and which usually respond well to a brief course of physiotherapy and muscle relaxants In 1.6% of patients, however, symptoms persist, become progressively more severe, and often involve a wider area of distribution because of entrapment of the intermediate trunk in addition to the lower trunk and C8 and T1 nerve roots Symptoms may recur from month to 10 years following initial rib resection In most instances, recurrence is within the first months Symptoms consist of aching or burning pain, often associated with paresthesia, involving the neck, shoulder, parascapular area, anterior chest wall, arm, and hand Vascular lesions are uncommon and consist of causalgia minor and infected false aneurysms There are two distinct groups of patients requiring reoperation Pseudorecurrence occurs in patients who never had relief of symptoms after the initial operation Cases can be separated etiologically as follows: cases in which (1) the second rib was mistakenly resected instead of the first; (2) the first rib was resected leaving a cervical rib; (3) a cervical rib was resected leaving an abnormal first rib; or (4) a second rib was resected leaving a rudimentary first rib The second group, in whom true recurrence takes place, includes those patients whose symptoms were relieved after the initial operation but who developed recurrence with a significant piece of Thoracic Outlet Syndrome / 203 the first rib remaining and those patients who had complete resection of the first rib but demonstrated excessive scar formation on the brachial plexus.18 Physiotherapy should be instituted in all patients with symptoms of neurovascular compression following first rib resection If symptoms persist and conduction velocity remains below normal, reoperation is indicated Reoperation for recurrent thoracic outlet syndrome is always performed through the posterior thoracoplasty approach to provide better exposure of the nerve roots and brachial plexus, thereby reducing the danger of injury to these structures as well as providing adequate exposure of the subclavian artery and vein It also provides a wider field for easy resection of any bony abnormalities or fibrous bands and allows extensive neurolysis of the nerve roots and brachial plexus, not always accessible through the limited exposure of the transaxillary approach The anterior or supraclavicular approach is inadequate for reoperation The basic elements of reoperation include (1) resection of persistent or recurrent bony remnants of either a cervical or the first rib, (2) neurolysis of the brachial plexus and nerve roots, and (3) dorsal sympathectomy Sympathectomy removes the T1, T2, and T3 thoracic ganglia The surgeon should avoid damaging the C8 ganglion—upper aspect of the stellate ganglion—which produces Horner syndrome This provides relief of major and minor causalgia and alleviates the paresthesias in the supraclavicular and infraclavicular areas The incidence of postsympathetic syndrome has been negligible in this group of patients The use of a nerve stimulator to differentiate scar from nerve root is cardinal to avoid damage in reoperation.18 The technique of the operation includes a high thoracoplasty incision, extending from cm above the angle of the scapula, halfway between the angle of the scapula and the spinous processes, and caudad cm from the angle of the scapula The trapezius and rhomboid muscles are divided the length of the incision The scapula is retracted from the chest wall by incising the latissimus dorsi over the fourth rib The posterior superior serratus muscle is divided and the sacrospinalis muscle is retracted medially The first rib remnant and cervical rib remnant, if present, are located and removed subperiosteally After the rib remnants have been resected, the regenerated periosteum is removed Most regenerated ribs occur from the end of an unresected segment of rib rather than from periosteum, although the latter is possible At the initial operation, therefore, it is important to remove the first rib totally to reduce the incidence of bony regeneration in all patients with primarily nerve compression and pain symptoms If excessive scar is present after removal of any bony rib remnant, it may be prudent to perform the sympathectomy initially This involves resection of a 1-inch segment of the second rib posteriorly to locate the sympathetic ganglion The first thoracic nerve may be easier to locate beneath rather than through the scar Neurolysis of the nerve root and brachial plexus is performed, using a nerve stimulator Neurolysis is carried down to but not into the nerve sheath It is extended peripherally over the brachial plexus as far as scar persists Excessive neurolysis is not indicated, and opening of the nerve sheath produces more scar than it relieves To minimize excessive scar, efforts in the initial operation for thoracic outlet should include complete removal of the first rib, avoidance of hematomas by adequate drainage either by a catheter or by opening the pleura, and avoidance of infection The subclavian artery and vein are released if symptoms mediate The scalenus medius muscle is debrided The dorsal sympathectomy is completed via extrapleural dissection Meticulous hemostasis is performed, and a large, round Jackson-Pratt catheter drain is placed in the area of the brachial plexus, although not touching it This drain is brought out through the subscapular space through a stab wound into the axilla Methylprednisolone acetate (Depo-Medrol) 80 mg is left in the area of the nerve plexus The patient is not given systemic steroids unless keloid formation has previously been manifested The wound is closed in layers with interrupted heavy polydiaxanone sutures to provide adequate strength The arm, kept in a sling, is to be used gently for the first months Range-of-motion exercises are prescribed to prevent shoulder limitation; however, overactivity is contraindicated to minimize excessive scar formation When the problem is vascular, involving false or mycotic aneurysms, special techniques for reoperation are used A bypass graft is interposed from the innominate or carotid artery proximally, through a separate tunnel distally, to the brachial artery Usually, the saphenous vein is used, although other conduits may be selected The arteries feeding and leaving the infected aneur ysm are ligated At a subsequent stage, the aneurysm is resected through a transaxillary approach with no fear of bleeding or ischemia of the arm Special instruments have been devised to provide adequate resection through the transaxillary or posterior route These include a modified strengthened pituitary rongeur and a modified Leksell double-action rongeur for first rib removal without danger to the nerve root The sympathectomy, which may be performed thorascopically in highly scarred patients, relieves chest wall pain that mimics angina pectoris, esophageal disease, or 204 / Advanced Therapy in Thoracic Surgery even a lung tumor by denervating the deep fibers that travel with the arteries and bone.26 Results of reoperation have been excellent if an accurate diagnosis was established and the proper procedure was executed Follow-up of over 400 patients has ranged from months to 15 years All patients improved initially after reoperation; in 79%, improvement was maintained for more than years Symptoms easily managed with physiotherapy developed in 14%; 7% required a second reoperation, in every instance because of rescarring No deaths occurred, and only one case of significant infection requiring drainage was recorded There have been isolated reports of using intra-arterial wall stents for recurrent thoracic outlet syndrome after surgical decompression Most of these patients have been anticoagulated However, long-term patency and symptomatology need to be evaluated before widespread use of wall stents.27 References Ranney D Thoracic outlet: an anatomical redefinition that makes clinical sense Clin Anat 1996;9:50–2 Urschel HC Jr The history of surgery for thoracic outlet syndrome Chest Surg Clin N Am 2000;1:183–8 Urschel HC Jr The transaxillary approach for treatment of thoracic outlet syndrome Chest Surg Clin N Am 1999;4:771–80 Urschel HC Jr, Razzuk MA, Hyland JW Thoracic outlet syndrome masquerading as coronary artery disease Ann Thorac Surg 1973;16:239–48 Urschel HC Jr, Razzuk MA, Wood RE, et al Objective diagnosis (ulnar nerve conduction velocity) and current therapy of thoracic outlet syndrome Ann Thorac Surg 1971;12:608–20 Caldwell JW, Crane CR, Krusen UL Nerve conduction studies in the diagnosis of the thoracic outlet syndrome South Med J 1971;64:310 Jebsen RH Motor conduction velocities in the median and ulnar nerves Arch Phys Med 1967;48:185 Rosati LM, Lord JW Neurovascular compression syndromes of the shoulder girdle Modern Surgical Monographs New York: Grune & Stratton; 1961 Adson AW Cervical ribs: symptoms, differential diagnosis for section of the scalenus anticus muscle J Int Coll Surg 1951;16:546 10 Jamieson WG, Chinnick B Thoracic outlet syndrome: fact or fancy? A review of 409 consecutive patients who under- went operation Can J Surg 1996;39:321 11 Urschel HC Jr, Razzuk MA Neurovascular compression in the thoracic outlet: changing management over 50 years Ann Surg 1998;228:609–17 12 Kuntz A Afferent innervation of peripheral blood vessels through sympathetic trunks South Med J 1951;44:673 13 Lang EK Roentgenographic diagnosis of the neurovascular compression syndromes Radiology 1962;79:58 14 Le Forestier N, Moulonguet A, Maisonobe T, et al True neurogenic thoracic outlet syndrome: electrophysiologic diagnosis in six cases Muscle Nerve 1998;21:1129 15 Roos DB, Owens JC Thoracic outlet syndrome Arch Surg 1966;93:71 16 Clagett OT Presidential address: research and prosearch J Thorac Cardiovasc Surg 1962;44:153 17 Falconer MA, Li FWP Resection of the first rib in costoclavicular compression of the brachial plexus Lancet 1961;1:59 18 Urschel HC Jr, Razzuk MA The failed operation for thoracic outlet syndrome: the difficulty of diagnosis and management Ann Thorac Surg 1986;42:523–8 19 Patel AN, Finlay KU, Urschel HC The effect of a perioperative paravertebral block on pain management after first rib resection 2002;15:374–5 20 Ohtusuka T, Wolf RK, Donsker SB Port-access first-rib resection Surg Endosc 1999;13:940 21 Paget J Clinical lectures and essays London: Longmans Green; 1875 22 Von Schroetter L Erkrankungen der fegasse In: Nathnogel Handbuch der Pathologie und Therapie Vienna: Holder; 1884 23 Angle N, Gelabert HA Safety and efficacy of early surgical decompression of the thoracic outlet for Paget-Schroetter syndrome Ann Vasc Surg 2001;15:37 24 Urschel HC, Razzuk MA Paget-Schroetter syndrome: what is the best management? Ann Thorac Surg 2000;69:1663–9 25 Adams JT, DeWeese JA Effort thrombosis of the axillary and subclavian veins J Trauma 1971;11:923 26 Urschel HC Jr Dorsal sympathectomy and management of thoracic outlet syndrome with VATS Ann Thorac Surg 1993;56:717 27 Cohen GS, Braunstein L Effort thrombosis: effective treatment with vascular stent after unrelieved venous stenosis following a surgical release procedure Cardiovasc Intervent Radiol 1996;19:37 CHAPTER 16 THE MANAGEMENT OF PLEURAL SPACE PROBLEMS ALEX G LITTLE, MD Anatomy tion of this magnitude, it is easy to understand how a seemingly minor perturbation in the system can result in the creation of a large pleural effusion Normally the pleural space contains less than mL of fluid Increases in this amount constitute a pleural effusion, which can be classified as an exudate or a transudate.1 A transudative effusion is the result of increased formation or decreased absorption of pleural fluid caused by changes in the Starling forces An exudative effusion results from inflammatory or malignant alterations or diseases of the pleura itself The effusion is considered to be exudative if analysis shows at least one of the following criteria: (1) pleural fluid protein divided by serum protein is greater than 0.5; (2) pleural fluid lactate dehydrogenase (LDH) divided by serum LDH is greater than 0.6; and (3) pleural fluid LDH is greater than two-thirds the upper limit of normal for the serum LDH Transudative effusions meet none of these criteria Depending on the size of an effusion and the status of the lungs, a range of symptoms may be seen If the effusion is small or the lungs can accommodate the effusion, the patient may be entirely asymptomatic When the effusion is larger or the lungs are unable to compensate, symptoms occur related to loss of lung volume and lung compression These include chest pain, cough, shortness of breath, and dyspnea on exertion Extreme cases can cause mediastinal shift leading to hemodynamic instability The pleura is a serous membrane The visceral pleura covers the lung parenchyma while the parietal pleura lines the inside of the thoracic cage, both the chest wall and the mediastinum Both pleural components are composed of a single layer of metabolically active mesothelial cells that can absorb or secrete fluid Pathophysiology Fluid movement, or flux, in or out of any anatomic space, including the pleural cavity, is determined by the relationship described by Starling between hydrostatic and oncotic pressures (the Starling forces) on each side of the membrane separating the space from the tissues, by the permeability of the membrane to fluid and macromolecules, and by the efficiency of lymphatic drainage of the space When equilibrium is reached, the amount of fluid in the anatomic space is constant Changes in any of these causes fluid movement in or out of the space to occur When considering the pleural cavity as an anatomic space, this means that potential causes of pleural effusion include (1) increased hydrostatic pressure from heart failure, (2) decreased intravascular oncotic pressure from hypoalbuminemia, (3) decreased intrapleural pressure from atelectasis of the lung, (4) inefficient pleural lymphatic drainage because of obstructing mediastinal tumor, and (5) increased capillary permeability from inflammation of or tumor implants on either the visceral or the parietal pleura Under normal circumstances, between one and two liters of pleura fluid flow daily from the parietal through the visceral or mediastinal pleura into mediastinal lymphatics and ultimately the systemic venous circulation With fluid production and absorp- Malignant Pleural Effusion Malignant pleural effusion complicates the care and worsens the quality of life of many cancer patients The most typical pathogenetic situation is involvement of parietal or visceral pleura with metastatic deposits These 205 206 / Advanced Therapy in Thoracic Surgery metastases leak fluid and blood from weakened capillaries, producing the frequently bloody pleural effusion In addition, both hypoalbuminemia, caused by cancer cachexia, and metastatic tumor blockage of mediastinal lymphatic pathways can contribute to or even independently cause a malignant pleural effusion Roughly 40% of clinically significant pleural effusions are caused by malignancy with the most common types being lung cancer, breast cancer, and lymphoma Obviously, there is a difference in tumor types between men and women Table 16-1, adapted from Johnson, gives a complete breakdown of the cancers most commonly associated with development of malignant effusions.2 This translates into approximately 100,000 new cases of malignant pleural effusion diagnosed each year in the United States The frequency with which this entity devastates the quality of the remaining short life of cancer patients mandates appropriate and aggressive management by thoracic oncologists TABLE 16-1 Etiology of Malignant Pleural Effusion Men Primary Tumor Women Incidence (%) Lung Lymphoma or leukemia Gastrointestinal tract Other 49.1 21.1 7.0 21.8 Primary Tumor Incidence (%) Breast Female genital tract Lung Lymphoma or leukemia Other 37.4 20.3 15.0 8.0 19.3 Adapted from Johnson ww.2 Diagnosis A malignant pleural effusion is an effusion associated with metastatic pleural nodules or bulky mediastinal disease in lymph nodes The former etiology is the most common, so the majority of patients have identifiable malignant cells in the fluid However, this is not always the case Therefore the effusion is considered malignant if it is associated with metastatic deposits either in the mediastinum or on a pleural surface, regardless of the presence or absence of malignant cells in the pleural fluid When a pleural effusion develops in the setting of a patient who already is known to have metastatic cancer, diagnosis is usually not a significant issue If the effusion is not causing symptoms, attention is directed toward therapy to address the systemic disease (ie, chemotherapy) When the effusion is causing the patient enough respiratory embarrassment to require specific local treatment, the diagnosis can be confirmed at the time therapy is begun A patient without a history of cancer who presents with a new pleural effusion, however, presents a diagnos- tic challenge The initial step in the investigation of this initially idiopathic effusion is to investigate potential causes of transudative effusions such as congestive heart failure and causes of exudative effusion such as infection Once these potential causes of idiopathic effusion have been thoroughly evaluated with the appropriate clinical investigations and eliminated as etiologic possibilities, the next step is either thoracentesis, with both chemical analysis and cytologic evaluation of the fluid, or closed pleural biopsy The majority of patients will eventually be proved to have malignant effusions One large study of 414 patients with idiopathic pleural effusion identified malignancy by one of these two methods in 281 (68%) cases.4 The cytologic examination of fluid obtained by thoracentesis was positive for cancer in 163 (58%) of the cancer patient population Closed pleural biopsy was positive in 121 (43%) of the patients but was diagnostic only 7% of the time when an earlier thoracentesis was nondiagnostic However, this means that 133 (32%) patients did not have a diagnosis established by either of these interventions Multiple other reports confirm that up to 27% of patients with effusions of unknown origin remain without a diagnosis after thoracentesis or pleural biopsy.2,3,5,6 Video-assisted thoracic surgery (VATS) is a safe and efficacious diagnostic option when these less invasive maneuvers have been unsuccessful General anesthesia and one-lung ventilation are required However, frequently only one access port is needed, so the procedure truly is minimally invasive With an operating telescope (Figure 16-1) fluid can be aspirated and biopsies taken through the operating port This translates into minimal postoperative patient discomfort; a chest tube can be placed through the same incision This intervention permits evacuation of all loculated fluid collections, FIGURE 16-1 The bottom instrument is a right-angled operating thoracoscope The camera is attached to the eyepiece and either a suction instrument (top) or biopsy forceps (middle) can be passed through the operating channel of the thoracoscope This instrument can be used to visually explore the pleural cavity, evacuate loculated fluid pockets, and biopsy pleural, pulmonary, and lymph node lesions through a single, small access incision The Management of Pleural Space Problems / 207 as well as visualization and biopsy of visceral and parietal pleural nodules that are not identifiable otherwise One of my patients is an illustrative example She had an idiopathic effusion; a computed axial tomography scan showed only the effusion At VATS exploration there were multiple small (less than mm) nodules studding the parietal pleura Biopsy showed these to be metastatic breast cancer 10 years following contralateral mastectomy In addition to pleural lesions such as in my patient, suspicious mediastinal and hilar lymph nodes can also be sampled for histologic examination and culture In multiple clinical reports VATS has been shown to have a sensitivity ranging between 80 to 100% for both benign and malignant disease.5–9 False-negative results are very uncommon, and specificity is generally reported as 100% In one experience with 161 patients with an idiopathic pleural effusion, 24 of 35 (69%) patients with two or more nondiagnostic thoracenteses were ultimately found by VATS to have either a primary or metastatic pleural malignancy.5 Of another 41 patients from the same study with nondiagnostic closed pleural biopsy, VATS successfully identified a malignant ideology in 27 patients (66%) In this particular investigation, the diagnostic sensitivity of thoracoscopy for malignancy was 95%, specificity was 100%, and the negative predictive value of VATS was 94% The sensitivity and specificity were both 100% for benign disease These results were obtained with minor complications, and the average hospital length of stay, which also included performance of and recovery from therapeutic maneuvers, was 10 days Only one procedure resulted in death As these experiences show, a VATS or thoracoscopic type of diagnostic intervention in cancer patients is generally both efficacious and well tolerated and associated with minimal morbidity However, both thoracentesis and closed pleural biopsy are less invasive, can be performed at the bedside, and result in a definitive diagnosis in approximately two-thirds of patients Therefore, despite reports suggesting the use of VATS as the initial diagnostic step, this approach should generally be reserved for patients in whom thoracentesis or closed biopsy are not diagnostic.9 therapeutic thoracentesis is appropriate If removal of a clinically significant quantity of pleural fluid produces no change in the patient’s respiratory symptoms, which might be due to lung disease such as emphysema or to primary or secondary lung malignancy, again no treatment is indicated Treatment The aggressiveness with which treatment should be pursued is dependent upon the extent to which a malignant pleural effusion produces respiratory symptoms and the patient’s performance status If the patient does not have respiratory compromise or is in the terminal phase of disease, no specific local treatment is necessarily indicated When the clinical picture is ambiguous and it is not clear whether the effusion or the underlying lung disease is responsible for the clinical picture, a single video-assisted thoracic surgery Some patients, up to 30% in some series, fail to respond to chemical pleurodesis with various sclerosants via a chest tube.3,5,10 The result is that the malignant effusion either persists or recurs This necessitates alternative therapy VATS exploration and drainage allows evacuation of loculated fluid collections that are not drainable by a routine chest tube This accomplishment is combined with intraoperative powdered talc insufflation, which ensures an even coverage of all pleural surfaces, thus thoracostomy and pleurodesis When respiratory symptoms are present or thoracentesis relieves respiratory embarrassment, suggesting that the patient’s quality of life can be improved by reexpansion of compressed lung, then treatment strategies are undertaken Placement of an intercostal chest tube and instituting tube thoracostomy drainage is the standard first step This is followed by instillation of a chemical sclerosant through the chest tube to produce pleural inflammation, which will result in fibrous adhesions between the visceral and parietal pleura, establish pleurodesis, and treat the effusion by eliminating the pleural space Although some physicians proceed quickly to pleurodesis after chest tube placement, I prefer to wait up to days for fluid drainage to decrease below 250 cc/d This may help to maximize contact between the visceral and parietal pleural surfaces by minimizing the tendency of accumulating fluid to keep them apart However, a lengthy delay is inappropriate; sclerosis should be attempted within days of chest tube placement regardless of the volume of drainage Various chemical agents have been used in the past as pleural sclerosant Presently, talcum powder, either two grams in the powder form or two to five grams mixed with saline to constitute a slurry, is the preferred agent for pleurodesis There is both experimental evidence10 and clinical experience11 that talc successfully promotes adhesion formation between the two pleural surfaces and results in clinical resolution in more than 90% of patients I prefer the powder form as it disperses quickly and completely throughout the pleural space following injection with a bulb syringe through the chest tube When it is installed in slurry form, the chest tube should be clamped for a brief period to allow the slurry to migrate within the pleural space 208 / Advanced Therapy in Thoracic Surgery promoting extensive adhesion formation and a successful pleurodesis With more experience this approach may become appropriate as a primary undertaking to simultaneously satisfy diagnostic and therapeutic goals At present, a VATS intervention should be withheld until at least one attempt has been made at pleurodesis via a chest tube However, this approach is effective.8,12,13 In one report of 34 patients, a VATS intervention with talc insufflation was successful in controlling the effusion in 32 of the patients.8 Another prospective investigation compared 85 patients treated with tube thoracostomy drainage and either bleomycin or tetracycline sclerosis with 39 patients treated with talc insufflation after VATS evacuation of all fluid.12 Analyzing patients who survived their malignant disease process, the VATS group had a 95% success rate at 90 days compared with a 70% success rate for the bleomycin-treated patients and a 47% success rate for the tetracycline group Although some of this difference may be due to the superior efficiency of talc compared with the other agents, these results certainly establish the high success rate that can be obtained with a VATS intervention, even in a significantly compromised patient population A VATS parietal pleurectomy is the most aggressive therapeutic option available Assuming that this approach has the same effectiveness as an open pleurectomy, this is the most definitive procedure available However, it is a more extensive surgical undertaking than talc poudrage and can be associated with some blood loss Given the efficacy of VATS fluid evacuation and talc poudrage in the context of the overall debility and limited life expectancy of this patient population, pleurectomy probably is appropriate for only occasional, carefully selected patients shunts and catheters Pleuroperitoneal and pleurovenous shunts represent alternative treatment options for select patients.15 These devices are rarely appropriate for initial therapy but are suited for patients when tube thoracostomy or VATS sclerosis either fails completely or achieves only partial success and there are persistent, loculated fluid collections These devices can be placed under local anesthesia and their effectiveness has been documented.15 However, it is necessary for either the patient or a family member to regularly compress the subcutaneous pump chamber to achieve fluid movement If this is not done, only minimal spontaneous fluid flow occurs In contrast to pressure-driven flow through a peritoneovenous shunt for ascites, the absence of an appropriate pressure gradient between the pleural cavity and either the peritoneal cavity or the venous system results in little or no fluid transfer on a spontaneous basis Alternatively, indwelling pleural catheter systems may be considered and used to withdraw aliquots of pleural fluid as necessary to relieve symptoms Their use requires the patient to tolerate an external device and results in loss of protein-rich fluid as the pleural contents are aspirated and discarded Nonetheless, their use has been shown to be associated with both decreased hospitalization time and less cost than chest tube placement and pleural sclerosis, and this is a legitimate alternative therapeutic option.16 Pleural Space Infections Definitions A parapneumonic effusion is any pleural effusion associated with bacterial pneumonia Parapneumonic effusions can be classified as simple effusions, complicated effusions, or empyemas Simple parapneumonic effusions are uninfected, free-flowing fluid collections; complicated parapneumonic effusions are early infected fluid collections, and thoracic empyemas are well-established collections of pus within the pleural cavity.17 Parapneumonic effusion develops in 36 to 57% of patients with pneumonia, although less than 5% of these progress to empyema Parapneumonic effusion (40 to 60%), prior thoracic surgery (15 to 30%), and thoracic trauma (10%) are responsible for most cases of empyema.18 The morbidity and mortality of patients with parapneumonic effusion is higher than in patients with pneumonia alone due in part to the need for management of the pleural effusion Prognosis is worse in the elderly, in patients with coexistent cardiac, pulmonary, or renal disease, and in patients with hospital-acquired or culture-positive empyema, especially those involving gram-negative bacteria or multiple pathogens Clinical Presentation Clinical manifestations vary depending upon the underlying pulmonary process, the responsible organism, the quantity of bacteria and fluid in the pleural space, the stage of the disease, and the host defense mechanisms The clinical presentation can range from an absence of symptoms to a severe febrile illness with toxemia and shock In general, it is difficult to distinguish patients with infected pleural effusions from those with sterile parapneumonic effusions on the basis of history and physical examination because of the underlying pulmonary infectious process Clinical manifestations include fever, dyspnea, chest pain, and cough with mucopurulent sputum Infected pleural effusions due to aerobic organisms usually manifest acutely, whereas in anaerobic pleuropulmonary infections the time course is usually more protracted Factors predisposing to aspira- The Management of Pleural Space Problems / 209 tion such as alcoholism, unconsciousness, and periodontal disease are common in patients with anaerobic infections Occasionally an empyema or a complicated effusion is manifested by failure of response or worsening of the clinical condition despite adequate antibiotic therapy for pneumonia A sudden expectoration of a large amount of purulent sputum or hemoptysis suggests the development of a bronchopleural fistula (BPF) Physical examination often reveals decreased breaths sounds, dull percussion, and restricted respiratory excursions Although rales from an associated pneumonia may be heard, the presence of a pleural friction rub is not distinctive With chronicity, an empyema can erode the chest wall and present as a spontaneously draining subcutaneous abscess known as empyema necessitatis Other manifestations of chronic empyema include chondritis and osteomyelitis of the ribs, pericarditis, mediastinal and vertebral abscesses, disseminated infection, and multiorgan failure Anemia and leukocytosis may be present but are nonspecific In stage 1, or the exudative stage, the pleural fluid is a thin exudate with a white blood count (WBC) less than 1,000 cells/mm3, LDH below 500–1,000 U/L, pH greater than 7.20, and a glucose level greater than 40 mg/dL This is also called a simple parapneumonic effusion Stage 2, or the fibrinopurulent or transitional stage, is characterized by infection of the pleural fluid The fluid is turbid and contains bacteria and cellular debris The pleural fluid glucose is usually less than 40 mg/dL, the LDH greater than 1,000 U/L, the WBC greater than 5,000/mm3, and the pH less than 7.20 Fibrin is deposited parallel to the pleural surfaces, and as the stage progresses, fibrinopurulent membranes partition the pleural space into two or more loculations As the fluid thickens, amorphous gelatinous masses adhere to the pleural surfaces compromising lung expansion This is also termed a complicated parapneumonic effusion If untreated, the fluid becomes frankly purulent, giving rise to a true empyema During this stage loculations prevent extension of the infectious process but make evacuation of the pleural cavity by nonsurgical means progressively difficult In stage 3, the chronic or organizing stage, fibroblasts migrate into the pleural cavity and produce an inelastic membrane called the pleural peel or cortex, entrapping the lung and rendering it essentially functionless Imaging plain roentgenograms The posterior-anterior and lateral chest radiographs are the best initial diagnostic modalities When the patient is upright, free pleural fluid first accumulates in the lowest part of the hemithorax, the posterior costophrenic angles Lateral decubitus views allow detection of 50 to 100 mL of fluid and the presence of loculation if the fluid fails to layer out along the dependent chest computed tomography Computed tomography (CT) is of great value in the overall evaluation of parapneumonic effusions and should be done early in the assessment of patients with complex parapneumonic effusion or empyema CT is helpful in (1) differentiating pleural fluid from peripheral parenchymal infiltrates or pleural thickening, (2) evaluating the parenchymal disease, (3) determining loculation, (4) characterizing the pleural surfaces, and (5) guiding and assessing therapy Management The therapeutic armamentarium for parapneumonic effusion or empyema includes antibiotic therapy, thoracentesis, tube thoracostomy, radiologic-guided percutaneous catheter drainage, intrapleural fibrinolytic agents, and a variety of surgical drainage procedures including VATS and open thoracotomy.18–23 Table 16-2 depicts an overview of the classification, diagnostic criteria, and treatment options of parapneumonic effusions The initial diagnostic challenge is to distinguish pleural effusions that will respond to antimicrobial therapy alone from collections that require tube thoracostomy or surgical drainage for their resolution Uncomplicated parapneumonic effusions usually require no specific therapy Treatment of the underlying pneumonia is the basis of therapy Thoracentesis or, rarely, thoracostomy tube drainage of the pleural fluid is appropriate for large fluid collections causing respiratory compromise by compression of the adjacent lung Once the diagnosis of a complicated parapneumonic effusion or empyema has been established, treatment follows the traditional guidelines for managing any abscess: (1) antibiotic therapy to control the underlying infection, (2) adequate drainage, and (3) obliteration of the dead space Infected pleural effusions should be approached and treated with the same urgency as an intra-abdominal abscess or as any other collection of pus in any body cavity antibiotics Early appropriate antimicrobial therapy for pneumonia minimizes the development of parapneumonic effusion and aborts the progression of uncomplicated effusion to complicated effusion or empyema Antimicrobial agents that are able to penetrate the pleural compartment in sufficient quantities to achieve and exceed the minimal inhibitory concentration include penicillins, cephalosporins, aztreonam, clindamycin, and ciprofloxacin The Management of Pleural Space Problems / 211 emphysema, chest wall hematoma, hemothorax, lung laceration, chylothorax, and injury to mediastinal structures, diaphragm, or intra-abdominal viscera intraplueral fibrinolytic agents Enzymatic debridement of the pleural space using fibrinolytic agents such as streptokinase (SK) or urokinase (UK) facilitates chest tube drainage of loculated or viscous early stage fibrinopurulent collections SK or UK is administered as a solution of 250,000 U in 100 mL of sterile normal saline via chest tubes or catheters The chest tubes are clamped, and patients are encouraged to change their positions at regular intervals to enhance distribution of the instilled agent After to hours, the chest tubes are unclamped and placed back on suction This procedure can be repeated daily until clinical FIGURE 16-2 A, This chest radiograph shows a right lower lobe pneumonia associated with a pleural effusion B, Chest computed axial tomography scan also shows the pneumonia and demonstrates that there is only one fluid collection; ie, there are no loculations Thoracentesis documented bacteria in this parapneumonic effusion, which resolved with appropriate antibiotic coverage and chest tube drainage 212 / Advanced Therapy in Thoracic Surgery improvement is achieved, radiographic resolution is obtained, or significant pleural fluid drainage ceases Success rates for fibrinolytic agents vary between 70 and 90% and are influenced by the appropriate selection of patients 24 A good outcome is usually obtained in complicated effusions and early empyemas Operative Management anesthetic management A double lumen endotracheal tube for contralateral lung ventilation is essential for access during a VATS procedure and helpful for open thoracotomy The double lumen tube also helps prevent contamination of the dependent lung Postoperative pain control is essential for unrestricted breathing and coughing, which are necessary to maintain adequate ventilation and clearance of pulmonary secretions Epidural analgesia is ideally suited for this purpose Early ambulation with portable suction devices, incentive spirometry, and chest physiotherapy should be instituted routinely All patients receive heparin subcutaneously or are fitted with sequential compression devices for prophylaxis against deep venous thrombosis video-assisted thoracic surgery VATS is gaining popularity in the management of patients with complex parapneumonic effusions or early empyema and is competitive with open thoracotomy Timely management and patient selection are critical for its success 21,22 VATS is particularly useful during the fibrinopurulent stage of empyema and in the presence of the radiology findings depicted in Figure 16-3, which shows a multilocular process that will not be sufficiently drained with tube thoracostomy alone At this stage, empyemolysis is achieved with complete breakdown of all loculations and drainage of the gelatinous exudate from the pleural cavity Early fibrin membranes or thin peels can usually be removed from the visceral pleura to allow lung reexpansion A unilocular space and full lung expansion must be achieved at the completion of the procedure Before closure, chest tubes are placed for postoperative drainage of the pleural space The tubes are removed when there are no remaining signs of infection and drainage is serous and less than 50–100 mL/d Once the empyema has progressed to the organized state, VATS is often unsuccessful due to the thicker and more adherent pleural peel entrapping the lung and an open procedure becomes mandatory In borderline cases, VATS can be used as an initial step Some of these early organizing empyemas can be dealt with by VATS, while in more advanced cases VATS can assist in identifying the most appropriate site for thoracotomy incision to approach the empyema thoracotomy Samson and Buford proposed early thoracotomy for evacuation of pleural space infections; however, this time-honored surgical technique is being supplanted by VATS for many patients Thoracotomy is usually performed during stage and the initial part of stage when the pleural surfaces are covered by amorphous gelatinous fluid collections but a true fibrous peel has not formed 20 Blunt finger dissection usually suffices to disrupt the fibrinous septations and allows access to all other areas of the pleural cavity Total elimination of fibrin membranes from the lung, diaphragm, and parietal pleura facilitates immediate and full lung reexpansion Thoracostomy tubes are placed anteriorly and posteriorly; additional chest tubes or Jackson-Pratt drains may be used to drain more inaccessible areas The earlier the drainage procedure is performed the better the outcome provided the underlying pulmonary process is adequately addressed and completely resolved with antibiotic therapy decortication A chronic empyema develops due to (1) delay in diagnosis, (2) inadequate drainage in the acute stage, (3) continuing reinfection from a BPF, (4) retained hemothorax, and (5) specific infections such as tuberculosis and fungal infections In this situation, a true decortication procedure is required for removal of the cortex of fibrous tissue entrapping and restricting the lung The major indications for decortication are the formation of a fibrous peel or cortex as a result of chronic empyema, a chronic organized hemothorax, and tuberculosis pleuritis with lung entrapment.23 The goals of therapy are to limit morbidity and mortality, shorten hospital stay, and return pulmonary function to baseline The principles for successful decortication include the following: (1) removal of the fibrin membranes overlying the visceral pleura to promote complete reexpansion of the collapsed lung, (2) adequate wide exposure, (3) development of a proper plane of cleavage between the peel and the visceral pleura, (4) removal of the firmly attached fibrous cortex by sharp dissection, (5) complete freeing of the lung to achieve circumferential mobilization and reexpansion, (6) closure of BPFs, (7) adequate hemostasis, and (8) wide drainage by placing two or more chest tubes or other drainage devices to assure complete evacuation and obliteration of any potential space.23 These principles are only achievable with an open thoracotomy I also find it helpful to continue ventilation 214 / Advanced Therapy in Thoracic Surgery References Light RW, MacGregor MI, Luchsinger PC, Ball WC Pleural effusions: the diagnostic separation of transudates and exudates Ann Intern Med 1972;77:507–13 Johnson WW The malignant pleural effusion: a review of cytopathologic diagnosis of 584 specimens from 472 consecutive patients Cancer 1985;56:905–10 Lynch TE Management of malignant pleural effusions Chest 1993;103:385–9 Prakash V Comparison of needle biopsy with cytologic analysis for evaluation of pleural effusions: analysis of 414 cases Mayo Clin Prac 1985;60:158–64 Harris RJ, Kavuru MS, Rice TW, et al The diagnostic and therapeutic utility of thoracoscopy Chest 1995;108:828–41 Harris RJ, Kavuru MS, Mehta AC, et al The impact of thoracoscopy on the management of pleural disease Chest 1995;107:845–52 Colt HG Thoracoscopy A prospective study of safety and outcome Chest 1995;108:324–9 Yim APC, Chun SS, Lee TW, et al Thoracoscopic management of malignant pleural effusions Chest 1996;109:1234–8 Marel M, Stastny B, Melinova L, et al Diagnosis of pleural effusions Chest 1995;107:1598–603 10 Bresticker MA, Oba J, LoCicero J, Greene R Optimal pleurodesis: a comparison study Ann Thorac Surg 1993;55:364–7 11 Webb WR, Ozmen V, Moulder PV, et al Iodized talc pleurodesis for the treatment of pleural effusions J Thorac Cardiovasc Surg 1992;103:881–6 12 Hartman DL, Gaither JM, Kesler KA, et al Comparison of insufflated talc under thoracoscopic guidance with standard tetracycline and bleomycin pleurodesis for control of malignant pleural effusions J Thorac Cardiovasc Surg 1993;105:743–8 13 Schulze M, Boehle AS, Kurdow R, et al Effective treatment of malignant pleural effusion by minimal invasive thoracic surgery Ann Thorac Surg 2001;71:1809–12 14 Waller DA, Morritt GN, Forty J Video-assisted thoracoscopic pleurectomy in the management of malignant pleural effusion Chest 1995;107:1454–6 15 Little AG, Kadowaki MH, Ferguson MK, et al Pleuroperitoneal shunting: alternative therapy for pleural effusions Ann Surg 1988;208:443–50 16 Putnam JB, Walsh GL, Swisher SG, et al Outpatient management of malignant pleural effusion by a chronic indwelling pleural catheter Ann Thorac Surg 2000;69:369–75 17 Light RW A new classification of parapneumonic effusions and empyema Chest 1995;108:299–301 18 Magovern CJ, Rusch VW Parapneumonic and posttraumatic pleural 14 space infections Chest Surg Clin N Am 1994;4:561–82 19 Light RW Management of parapneumonic effusions Chest 1991;100:892–3 20 LeMense GP, Strange C, Sahn SA Empyema thoracis therapeutic management and outcome Chest 1995;107:1532–7 21 Mackinlay TAA, Lyons GA, Chimondeguy DJ, et al VATS debridement versus thoracotomy in the treatment of loculated postpneumonia empyema Ann Thorac Surg 1996;61:1626–30 22 Landreneau RJ, Keenan RJ, Hazelrigg SR, et al Thoracoscopy for empyema and hemothorax Chest 1995;109:18–24 23 Martella AT, Santos GH Decortication for chronic postpneumonic empyema J Am Coll Surg 1995;180:573–6 24 Lee-Chiong TL, Matthay RA Current diagnostic and medical management of thoracic empyema Chest Surg Clin N Am 1996;6:419–37 CHAPTER 17 TECHNIQUES OF TRACHEAL RESECTION AND RECONSTRUCTION SIMON K ASHIKU, MD DOUGLAS J MATHISEN, MD A wide variety of conditions involve the trachea The most effective treatment for most of these abnormalities is tracheal resection Over the past 30 years, techniques have evolved that allow for singled-staged operations for lesions in the subglottis, trachea, or carina with excellent results Even long segments may be resected with the creation of a tension-free anastomoses utilizing “release” techniques This chapter focuses on the conditions amenable to tracheal resection followed by a more detailed discussion of the diagnostic and operative approaches to these problems The upper trachea is supplied principally by branches of the inferior thyroid artery and the lower trachea by branches of the bronchial arteries (Figure 17-1A and B) These vessels enter the trachea via very fine lateral pedicles that lack collateralization (Figure 17-2).5 To prevent devascularization of the suture line, the length of circumferentially dissected trachea must be limited to no more than cm proximal or distal to the transected airway Dissection along the pretracheal plane and the plane between the trachea and esophagus avoids the lateral vascular pedicles and can be safely performed to mobilize the trachea.6 The recurrent laryngeal nerves ascend in the tracheoesophageal grooves bilaterally and pass medial to the inferior cornua of the thyroid cartilage They enter the larynx at its junction with the cricoid posteriorly, adjacent to the cricoar ytenoid joints (Figure 17-3) Maintaining a plane of sharp dissection with scissors directly on the trachea is the best way to avoid injury to these nerves No attempt should be made to locate the recurrent laryngeal nerves in most cases Surgical Anatomy The adult trachea averages 11 cm in length from the lower border of the cricoid cartilage to the carinal spur There is an additional 1.5 to cm of subglottic intralaryngeal airway There are 18 to 22 cartilaginous rings, with approximately rings per centimeter The only complete cartilaginous ring in the normal airway is the cricoid cartilage, the remainder of the rings completing only an anterior arch The normal trachea will remain open even during extremes of coughing, in contrast to a malacic trachea which collapses with cough The blood supply and connective tissue attachments of the trachea specifically allow vertical movement of the trachea In a young person, hyperextension brings up to one-half of the trachea into the neck, and flexion devolves the trachea almost entirely into the mediastinum Therefore, neck flexion is a useful maneuver to relieve tension on tracheal anastomoses In elderly or kyphotic patients, the decreased extent of neck flexion limits the amount of trachea that can be safely resected without undue tension on the suture line.2–4 Conditions Treated by Tracheal Resection Surgically amenable tracheal lesions may arise from several different etiologies Those most common abnormalities treated with surgical resection are traumatic, neoplastic, and idiopathic Postintubation tracheal stenosis following prolonged intubation occurs principally at the level of the endotracheal tube or tracheostomy tube cuffs Stoma stenosis occurs with tracheostomies and is thought to be due to cicatricial healing of the anterior and lateral tracheal 215 218 / Advanced Therapy in Thoracic Surgery Clinical Presentation Despite the disparate etiologies of tracheal stenosis, all patients with compromise of their tracheal lumen present with similar signs and symptoms Progressive airway obstruction frequently begins with shortness of breath on exertion, then shortness of breath at rest, then wheezing or stridor Postintubation lesions generally present with these symptoms to weeks following extubation Tracheal malacia patients have a characteristic barking cough with an expiratory wheeze, while patients with pure stenosis tend to have stridor on inspiration Tracheal malignancies, in addition to bearing symptoms of airway obstruction, frequently present with cough and hemoptysis Extensive tumors may result in hoarseness or dysphagia Radiologic Assessment Once a tracheal lesion is suspected, the diagnosis is accomplished by simple radiologic studies.16,17 A standard posteroanterior chest radiograph, centered high on the trachea, will reveal most tracheal stenoses However, detailed information about the location of the lesion, its longitudinal extent, and the amount of normal trachea available for reconstruction is best demonstrated by logitudinal tomograms of the entire airway (Figure 17-7) This includes lateral projections of the extended neck to provide views of the larynx and upper trachea These can be supplemented by fluoroscopy to evaluate the functional state of the glottis and delineate areas of malacia FIGURE 17-5 Cuff level stenosis The stenosis here is circumferential and the remaining lumen round Reprinted with permission from Sabiston and Spencer Surgery of the chest 6th ed W.B Saunders p 413 FIGURE 17-6 An exophytic squamous cell carcinoma of the trachea Reprinted with permission from Sabiston and Spencer Surgery of the chest 6th ed W.B Saunders p 407 FIGURE 17-7 A, Plain pulmonary artery chest radiograph of cuff stenosis B, A typical tomographic view of the the same lesion Reprinted with permission from Sabiston Textbook of surgery 15th ed W.B Saunders p 1819 Techniques of Tracheal Resection and Reconstruction / 219 In general, the detailed longitudinal image provided by such conventional radiographs is of greater help to the surgeon than the cross-sectional images provided by computerized tomograms Virtually all the essential information is provided in a single view, giving the surgeon an accurate assessment of the lesions extent However, computed tomography (CT) is useful for evaluating tumors to identify extraluminal extension and enlarged mediastinal lymph nodes Recently, the use of high-speed helical CT scanners to acquire images combined with powerful three-dimensional imaging software has created impressive three-dimensional airway reconstructions It is not clear that any additional useful information is gained over that which can be obtained from the less expensive, linear tomograms It is important to stress that all of these studies must be performed without an indwelling tracheostomy tube In cases where a tracheostomy tube has been in place chronically and must be removed for the examinations, there must be a physician competent in tube replacement present in the event the airway is lost Bronchoscopy Expert bronchoscopic evaluation is essential to confirm diagnosis and plan operative strategy Interventional bronchoscopic techniques are usually required to clear the airway for complete preoperative evaluation, passage of endotracheal tube, and prevention of impending airway obstruction and to allow time for thorough preoperative evaluation and preperation The diagnosis of airway lesions is usually made on the basis of clinical history and radiographic appearence However, bronchoscopic evaluation is necessary to confirm the diagnosis either by the visual appearance in the case of benign strictures or with biopsies in the case of tumors Creating an operative strategy also requires a thorough evaluation of the lesion Careful bronchoscopic measurements determine the length of the lesion and the amount of normal trachea proximal and distal available for reconstruction Under the best of circumstances, up to 50% of the trachea can be resected and a primary anastomosis performed Mature surgical judgement is required to determine resectability since many factors such as age, body habitus, amount of cervical trachea and lesion location conspire to limit the amount of trachea that can be safely resected With benign strictures, special attention must be given to assessing the state of the mucosa When stents or T-tubes are in place, they must be removed and the mucosa assessed If extensive mucosal inflammation or ulceration exists, definitive repair should be delayed until mucosal healing occurs This may require a short period of decannulation or change to a smaller T-tube With idiopathic laryngotracheal stenosis, active inflammation extending into the subglottis demands temporizing dilatation and delay of operation while the inflammation subsides Parenthetically, patients taking systemic corticosteriods should be weaned from them and be off for at least a month before a definitive resection is attempted Familiarity with the techniques of interventional bronchoscopy are essential for the management of tracheal pathology The ability to safely dilate a benign stenosis or “core out” an obstructing tumor is required to evaluate the distal airway, allow safe passage of an endotracheal tube, temporarily reestablish a patent airway allowing delay in operation or to emergently manage an airway Dilating a narrow, fibrotic stricture, such as with postintubation stenosis, is challenging and can result in airway rupture, complete obstruction, or excessive destruction of tracheal mucosa In these situations, progressively larger Jackson dilators passed through the rigid bronchoscope can be used to effectively dilate the stenosis under direct vision An assortment of pediatric rigid bronchoscopes and adult rigid bronchoscopes can then be used with increasing sizes using a gentle corkscrew motion By gradually dilating these tight, rigid structures the risk of complications is minimized.18 Obtructing tracheal tumors are managed first by “core out” using the rigid bronchoscope, forceps, and suction.19 The relatively soft consistency and compressibilty of tumors allows a rigid bronchoscope to be passed beyond even near total obstructions After the distal airway is assessed, biosy forceps are used to partially debride the tumor to assess consistency and vascularity Using the tip of the bronchoscope in a corkscrew motion, most tumors can be easily cored out Forceps are then used to remove tumor fragments If bleeding ensues, the bronchoscope is advanced distal to the lesion and serves to tamponade the bleeding Direct application of epinephrine-soaked pledgets can stop persistant oozing Using the techniques discussed above virtually all lesions can be safely evaluated and managed 18 It is important, however, to stress a few key points Patients with critical airway stenosis should be endoscoped in the operating room where rigid bronchoscopy is available and ready for use Flexible bronchoscopes can precipitate airway obstruction in patients with critical airway stenosis (< mm) by inducing secretions, edema, and bleeding Without the ability to dilate and control the airway with rigid broncoscopy, death ensues rapidly Endoscopic removal of malignant or inflammatory lesions is only a temporary measure It is useful in allowing time for preoperative assessment and for the weaning of cortico- ... space-occupying fetal thoracic lesions is their impairment of the developing lung and their ability to impair cardiac performance through mediastinal shift 1 84 / Advanced Therapy in Thoracic Surgery. .. first innominate artery suspension for innominate artery compression syndrome Pulmonar y arter y sling was first described by Glaevecke and Doehle in 1897 based on a post-mortem finding in a 7-month-old... somatic pain being more common than visceral pain, the brain interprets activity arriving in a given pathway as a pain stimulus in a particular somatic area Two theories attempt to explain the mechanism