Thrombosis and thromboembolism - part 10 docx

Table 4 Factors to Consider in the Decision to Proceed with Surgical PulmonaryEmbolectomyContraindications to thrombolysisPossible indications Embolus in the central pul- Active internal

patients (Fig 3b) and only 20% could be attributed to the history of pulmonaryembolism—two following perioperative neurological injury, two from recurrentpulmonary embolism, and one from anticoagulation-related hemorrhage Fourdeaths from unknown causes may have been related to pulmonary embolism.The majority of deaths, however, were from unrelated causes, mostly cancer(36%) and trauma (16%).

Four studies report actuarial survival data (65,66,71,85) These survivalcurves all show a steep initial decline reflecting the 20 to 40% operative mortalityand a very flat portion thereafter reflecting the excellent mid- and long-term sur-vival in operative survivors (Fig 4) Medium-term (4–5 year) survival was 65

to 80% (65,66,71,85) and long-term (8–10 year) survival was 62 to 71% (65,66).Even patients who had suffered preoperative cardiac arrest and survived to dis-charge had excellent long-term survival (66)

2 Recurrent Pulmonary Embolism

Clinically significant recurrent pulmonary embolism appears to be rare Two tients, noted above, died from recurrent embolism There was only one additionalreport of a nonfatal embolism (71) Although these retrospective studies mightunderestimate the incidence, they are consistent with the relatively low rate ofrecurrent thromboembolism in patients treated medically after pulmonary embo-lism (86) In addition, most, but not all, centers routinely performed inferior vena

pa-Figure 4 Actuarial survival after pulmonary embolectomy with and without monary resuscitation (CPR) (From Ref 66.)

cardiopul-caval interruption to protect against recurrent embolism The three patients whodid suffer recurrent embolism had not undergone inferior vena caval interruptioneither as a matter of policy (75) or for technical reasons (71).

3 Functional Status

Six studies document New York Heart Association functional class in 176 tal survivors at a mean follow-up of 71 months (65,66,71,73,83,85) Nearly all(98%) were in Class I or II (Fig 5) One nonrandomized study from the mid-1980s compared late functional status among patients treated with heparin, strep-tokinase, or embolectomy (85) Although the surgical patients were more ill atpresentation, their late functional status was better with 45% in Class I compared

hospi-to 17% of medical patients No surgical patient was in Class III or IV compared

to 10% of medical patients

A recent study sought to correlate late functional status with objective nostic studies in 19 of 21 survivors of embolectomy at a mean follow-up of 8.4years (83) All patients underwent physical examination, ventilation-perfusionscintigraphy, echocardiography, and pulmonary function testing Class III pa-tients also underwent right heart catheterization and pulmonary arteriography.Using an explicit set of criteria, three-fourths of patients had at least one minorabnormality and one-fourth had a major abnormality The presence of minor ormajor abnormalities correlated well with the patient’s functional status, with ma-jor abnormalities occurring in only 12% of Class I or II patients but all ClassIII patients Eighty percent of patients with no abnormalities were in Class I

diag-Figure 5 Late functional status after pulmonary embolectomy in those major surgicalseries listed in Table 2 that report New York Heart Association (NYHA) functional class

Table 3 Late Mortality Among Survivors of

Number of late deaths 25 deaths

Overall late mortality rate 8%

Linearized late mortality rate 1.4% per year

unre-Another study found a similar incidence of minor abnormalities in 10 of

12 survivors of embolectomy (84) that the authors attributed to incomplete lectomy, intraoperative trauma with thrombosis, or small recurrent emboli Twopatients, both with a preoperative history of prior embolism, had major residualperfusion defects and pulmonary hypertension They conclude that patients withunderlying, chronic pulmonary thromboembolic disease have significantly worselong-term outcome

embo-III PREOPERATIVE EVALUATION

A Surgical Indications and Timing

1 Overall Strategy

There is no consensus on the indications for surgery in acute pulmonary embolism(Table 4) The decision is fairly straightforward at either extreme A stable patientwith multiple peripheral perfusion defects is clearly not a surgical candidate Onthe other hand, a patient in refractory cardiogenic shock with a documented sad-dle embolus, and a contraindication to thrombolysis, is certainly best served byemergency embolectomy Most patients, however, fall between these two ex-tremes and require careful individualized assessment to determine the optimalmanagement The indications for surgery should be part of a multidisciplinary

strategy that seeks to minimize overall morbidity and mortality using all available

modalities Embolectomy should be considered one tool which, if applied beforesevere hemodynamic compromise, can provide excellent short- and long-termresults A strategy that positions it as a treatment of last resort, to be avoided

Table 4 Factors to Consider in the Decision to Proceed with Surgical PulmonaryEmbolectomy

Contraindications to thrombolysisPossible indications

Embolus in the central pul- Active internal bleeding Age over 75

bi-Refractory cardiogenic Neurosurgical procedure Pregnancy or early

monthsRight atrial or ventricular Severe uncontrolled hyper- Recent trauma, including

?Severe right heart dysfun- Known bleeding diathesis Recent GI bleeding or

than 10 days)

?Elevated cardiac troponin Known allergy to thrombo- Known coagulation

de-lytic agents fects, including

anticoag-ulant therapy and nificant liver

sig-dysfunction

?Moderate hemodynamic High likelihood of leftcompromise or right heart thrombus (e.g., mi-heart dysfunction with tral stenosis with atrial

thrombolysis

unless other options have failed or are unavailable, is doomed, in my opinion,

to provide suboptimal results

2 Location of Pulmonary Emboli

The classic anatomical criteria for embolectomy have been over 50% obstruction

of the pulmonary vascular tree by pulmonary angiography The location of theemboli, however, may be as important as the degree of obstruction The idealpatient has large emboli in the central pulmonary arteries (at times accompanied

by right atrial thrombus) that can be completely removed in a few pieces resulting

in normalization of the pulmonary artery pressures and restoration of right heart

function A patient who has showered multiple emboli may also demonstratevascular obstruction approaching 50% but is not as good a surgical candidate.Complete embolectomy may not be possible in these patients without traumaticmaneuvers such as massaging the lungs, blind passage of instruments into theperiphery, or retrograde perfusion of the lungs through the pulmonary veins.

3 Hemodynamic Status

As we have seen from the results of the major surgical series, a specific center’sresults will primarily depend on its hemodynamic threshold for intervening surgi-

cally If surgery is limited to those patients in extremis, one can expect mortality

rates over 50% If surgery is applied more liberally with every effort to intervene

before the onset of shock or cardiac arrest, one can expect mortality rates as low

as 10%, comparable to patients undergoing thrombolysis (87) This dichotomy

is understandable given that the leading causes of operative death—right heartfailure, neurological injury, and multisystem organ failure—are a result of thepatient’s preoperative hemodynamic condition and not to the procedure itself.Pulmonary embolectomy, if applied with attention to minimizing pulmonary ar-tery trauma, is a relatively simple procedure that should carry little inherent risk

of death Cardiopulmonary bypass times should be short; cardioplegic arrestshould be unnecessary; and bleeding complications should be minimal.That some patients will always present with sudden cardiovascular collapsemay make it impossible to lower the overall mortality rate to less than 5 to 10%

unless patients in extremis are simply not offered surgery However, as

Trende-lenburg observed nearly a century ago, most patients have between 15 min andseveral hours before severe hemodynamic compromise ensues Utilizing this timeperiod effectively is the most critical challenge, with high stakes on both sides.Delaying surgery for a trial of medical therapy may avoid a major operation butmay risk converting a stable patient with an operative mortality of 5 to 10% toone in severe cardiogenic shock or cardiac arrest with a mortality of 40 to 60%.Sasahara’s classic hemodynamic criteria for embolectomy include refrac-tory cardiogenic shock (systolic pressure less than 90 mmHg) and oliguria (less

than 20 mL/h) despite maximal medical therapy or when thrombolytic therapy

is contraindicated (88) These stringent criteria, however, may withhold a tially life-saving procedure until irreversible cardiac and end-organ injury hasoccurred In my opinion, all patients with a hemodynamically significant centralembolus should be considered for surgery If the patient stabilizes with volumeand low-dose inotropic support, then thrombolytic therapy may be appropriate,but the surgical team must be kept on alert and notified early if the patient deterio-rates Invasive monitoring of cardiac output may permit intervention before end-organ injury The use of high-dose pressors during thrombolytic therapy to avoidsurgery at all costs is inappropriate

poten-4 Right Ventricular Function

Goldhaber (2) and others (89) have clearly demonstrated that right ventricularhypokinesis without systemic hypotension is a strong, independent risk factor forearly mortality and that this finding can be used to triage patients to more aggres-sive treatment In a large registry report, the 14-day mortality among the 40%

of patients with right ventricular hypokinesis was double that in those withoutthis finding (2) This risk stratification has typically been applied in selectingpatients for thrombolysis but may also be used in recommending embolectomy

in those patients with contraindications to thrombolysis, even if they are namically stable Evidence of severe right ventricular dysfunction might justifyproceeding with embolectomy even if thrombolytic therapy is not contraindi-cated

hemody-5 Right Atrial or Ventricular Thrombus

Mobile thrombus or ‘‘in-transit’’ emboli within the right atrium or right ventriclemay occur in up to 10 to 15% of patients with pulmonary embolism (90,91).Even modest-sized thrombi can be fatal if they embolize in a patient with moder-ate degrees of vascular obstruction and right heart dysfunction Because they areassociated with a high (⬎40%) mortality rate, their presence is generally consid-ered a strong indication for aggressive intervention Although thrombolysis hasbeen advocated for this condition (90,92,93), embolectomy may be the most ap-propriate treatment These thrombi can embolize at any time (94) and thromboly-sis may require several hours to achieve its maximal effect and might actuallypromote embolization In my opinion, the presence of mobile thrombi in the rightheart in a patient with documented central pulmonary emboli is a strong indica-tion for emergency surgery

6 Cardiac Enzymes

A recent report demonstrated that an elevated cardiac troponin T was present in32% of patients with pulmonary embolism, correlated well with the severity ofpresentation, and was a strong predictor of in-hospital mortality—44% vs 3%(95) On multivariate analysis, it was the only remaining independent predictor

of death (adjusted odds ratio 15.2) Although these results need confirmation,cardiac troponins may supplement echocardiography in triaging patients to ag-gressive treatment

7 Contraindications to Thrombolytic Therapy

Thrombolytic therapy has been shown to accelerate the resolution of emboli, thenormalization of pulmonary artery pressures and right heart function, and lowermortality in selected patients (96–98) The risk of intracranial hemorrhage is 1

to 3% and the risk of other major hemorrhage is 10 to 20% Some patients,however, have significantly higher risks of complications and thrombolytic ther-apy is contraindicated in them (Table 4) Patients with central pulmonary emboliwho have contraindications to thrombolytic therapy should be considered forsurgical embolectomy.

B Diagnostic Studies

1 Overall Strategy

A streamlined diagnostic approach, focusing on documenting central emboli asrapidly as possible, is critical to achieving good results in patients being consid-ered for embolectomy Once this has been done, the patient should be transported

to the operating room immediately even if relatively stable Echocardiography,

pulmonary angiography, and CT scanning all play important roles, but the cific tests performed depend on the patient’s clinical presentation, location, andwhat is available Although many patients will have undergone ventilation-perfu-sion scintigraphy at some point, this study is not particularly helpful in this set-ting Large perfusion defects may suggest central emboli but their actual locationcannot reliably be determined without a chest CT scan, pulmonary angiogram,

spe-or echocardiogram that shows thrombus in the main pulmonary arteries

2 Chest CT Scanning

Contrast-enhanced spiral chest CT has become increasingly popular in evaluatingpulmonary embolism (99,100) Its accuracy has been well documented in recentyears and is comparable to other noninvasive tests It may, in fact, be the idealstudy in Emergency Department patients with suspected major pulmonary embo-lism Although spiral CT is usually necessary to document peripheral emboli,large central emboli are usually well visualized with a standard chest CT scan

CT scanning is usually readily available, often in the Emergency Departmentitself, and can be performed in 10 to 15 min If central emboli are visualized inthe main or proximal branch pulmonary arteries, and if the patient is a candidatefor surgical embolectomy by clinical criteria, no further confirmatory testing isnecessary, and the patient can be immediately transported to the operating room

3 Echocardiography

Echocardiography, transthoracic and transesophageal, is also playing an ing role in the diagnosis and risk stratification of patients with pulmonary embo-lism (6,7,99,101,102) Although the pulmonary arteries themselves are often notwell visualized, echocardiography provides important prognostic information tohelp determine whether aggressive treatment should be considered Right heart

increas-function can be assessed, pulmonary artery pressures can be estimated, and bile thromboemboli in the right atrium or ventricle can be visualized Right ven-tricular hypokinesis is a strong predictor of poor outcome and may justifyaggressive treatment—thrombolysis or surgery—even if the patient is hemo-dynamically stable.

mo-Echocardiography may also be helpful as an initial study in a patient withsome hemodynamic compromise in whom the diagnosis of pulmonary embolism

is being considered If the echocardiogram is suggestive but not definitive, aconfirmatory CT scan or, more likely, pulmonary angiogram would be indicated

A tenuous patient, with clear-cut echocardiographic findings of a major nary embolism, who is considered a candidate for surgical embolectomy, could

pulmo-be taken to the operating room without further testing Intraoperative geal or surface echocardiography could then confirm the presence of central em-boli Intraoperative TEE is also the only available test in the occasional patientwho suffers a major pulmonary embolism on the operating room table duringanother operation Evidence of a major embolism by TEE may justify immediatesternotomy and embolectomy

transesopha-4 Pulmonary Angiography

Although pulmonary angiography remains the gold standard for diagnosing monary embolism, its role in evaluating patients for embolectomy should be lim-ited With spiral CT and echocardiography, most embolectomy patients will notneed preoperative angiography Clinically stable patients, with intermediate- tohigh-probability ventilation-perfusion scans, may undergo confirmatory angiog-raphy where unsuspected, massive central pulmonary embolism requiring surgery

pul-is dpul-iscovered Other patients, with echocardiographic findings suggestive of alarge embolism, might need angiography to define the anatomical distribution ofemboli and to determine whether surgical embolectomy is appropriate

IV INTRA- AND POSTOPERATIVE MANAGEMENT

A Basic Principles

Patients selected for embolectomy should be immediately transported to the erating room even if they ‘‘appear’’ relatively stable In our hospital, patients godirectly from the radiology suite or ward to the operating room without stopping

op-in the op-intensive care unit for ‘‘stabilization.’’ Resuscitation can be performed en route and in the operating room Patients from outside hospitals are transferred

directly to the operating room by helicopter In the operating room, teamwork

is critical and only essential preoperative maneuvers are performed so the patientcan be placed on cardiopulmonary bypass without delay

vascula-Although an arterial monitoring line and large-bore venous access are essary prior to induction, central venous access can be deferred until after thepatient is on bypass A pulmonary artery catheter is critical for weaning frombypass and postoperative management but the dilated right heart can make ad-vancing the catheter difficult and time-consuming The introducer sheath can be

nec-inserted and the catheter advanced with the surgeon’s guidance after

embolec-tomy and prior to weaning from bypass

lar volumes to help determine whether to treat the patient with volume, inotropicagents, pulmonary vasodilators, or systemic vasoconstrictors.

D Surgical Technique

1 Incision and Cardiopulmonary Bypass

Embolectomy is performed through a full median sternotomy that provides goodexposure of the pulmonary arteries, vena cavae, and right heart chambers Afterpericardiotomy and full heparinization, the patient is cannulated for cardiopulmo-nary bypass Arterial cannulation is usually performed in the distal ascendingaorta The most common technique for venous cannulation is to place separatecannulae in the superior and inferior vena cavae with tourniquets to prevent airfrom entering the venous line when the pulmonary artery or right heart is opened.The availability of intraoperative TEE has allowed us to simplify our venouscannulation technique We explore the right atrium and ventricle only if the TEE(or surface echo) demonstrates mobile thromboemboli In addition, we routinelyemploy vacuum-assisted venous drainage that is not affected by moderateamounts of air in the venous line This allows us to rapidly cannulate the rightatrium through the appendage using a standard two-stage venous cannula Thistechnique works even in situations where right heart exploration is necessary.With vacuum-assisted venous drainage, the right atrium can be explored withoutseparately controlling the vena cavae

Although some authors report using aortic cross-clamping and cardioplegic

or fibrillatory arrest, this is, in my opinion, never necessary and always potentiallydetrimental Pulmonary embolectomy and right heart exploration can easily beperformed with the heart beating under normothermic conditions Some degree

of right heart stunning is almost always present and aortic cross-clamping andcardiac arrest add an additional ischemic insult that risks further stunning andright heart dysfunction Performing the operation on the unloaded, well-perfusedbeating heart not only avoids any further ischemic insult but also provides timefor the heart to recover and regenerate its depleted energy stores

2 Exploration of the Right Atrium and Ventricle

If echocardiography demonstrates mobile thromboemboli in the right atrium orright ventricle, exploration of these chambers is mandatory and should be per-formed prior to embolectomy Cannulating the right atrium and inferior venacava in patients with right atrial thrombus must be performed with caution toprevent dislodging the thrombus or aspirating it into the venous line In thesesituations we cannulate the right atrium while visualizing it and the thrombus byTEE The cannula is advanced just far enough to achieve adequate venous drain-

age to initiate bypass The right atrium is then opened and explored with thevenous cannula on vacuum suction The right ventricle is inspected through thetricuspid valve and later through the pulmonary valve The venous cannula isrepositioned after confirming that the right heart is completely free of clot byTEE.

3 Pulmonary Arteriotomy and Embolectomy

Once cardiopulmonary bypass has been established, the actual embolectomy gins with an incision over the main pulmonary artery Some surgeons use a longi-tudinal incision starting just below the pulmonary valve, but we find that a verylow transverse incision provides better visualization and can be extended ontothe branch pulmonary arteries if necessary The proximal portion of the clot isusually immediately apparent, especially if a saddle embolus is present The clot

be-is then gently extracted in a hand-over-hand fashion using simple gallbladderstone forceps If this is done carefully, the clot can usually be removed en bloc,emerging as a cast of the femoral vein Once the large central clots have beenremoved, the entire pulmonary vascular tree is inspected With good head-mounted lighting and firm anterior retraction of the aorta, all segmental pulmo-nary artery branches, except, occasionally, the individual basal segments, can be

cleared of emboli under direct vision using the stone forceps or a small

suction-tipped catheter

Many other techniques for clot extraction have been utilized and advocated

in the literature I believe that these techniques are not only unnecessary butexcessively traumatic and potentially dangerous The pulmonary arteries are veryfragile and trauma to these vessels from overaggressive or blind instrumentationcan lead to pulmonary hemorrhage, which is usually fatal If patients for embolec-tomy are carefully selected to include only those with large central emboli, then

simple extraction of all visible central and distal clots will result in nearly

com-plete normalization of pulmonary artery pressures Leaving small, peripheralemboli behind is preferable to performing dangerous blind maneuvers to achieve

a perfectly complete embolectomy The pulmonary vasculature is known to sess a great capacity for fibrinolysis and may clear these peripheral emboli overtime

pos-Among these adjunctive techniques, blind Fogarty balloon catheter lectomy is particularly worthy of criticism Even if this technique did not riskpulmonary artery perforation and fatal pulmonary hemorrhage, it is unlikely to

embo-be particularly effective The likelihood of advancing the catheter into each mental branch, without visual guidance, is very low Several Japanese centershave advocated using fiberoptic angioscopy to help visualize and extract smallperipheral emboli Although theoretically attractive, this technique can be time-

seg-consuming and requires additional equipment that might not be available duringthe off-hours Again, the benefit of extracting a few more peripheral emboli isunlikely to be worth the effort Massaging the lungs to dislodge peripheral emboli

is also potentially traumatic and may promote postoperative pulmonary edema.Without active retrograde blood flow, it seems unlikely that a significant amount

of dislodged clot would find its way back to the central pulmonary arteries grade perfusion of the lungs through the pulmonary veins, although theoreti-cally attractive, requires aortic cross-clamping, cardioplegic arrest, opening ofthe left atrium, and deairing the left heart The cumulative risk of these maneuversdoes not justify the theoretical benefit of extracting a few more peripheral emboli

Retro-4 Weaning from Cardiopulmonary Bypass

The primary issue in weaning patients from cardiopulmonary bypass after lectomy is right ventricular function Although most patients will demonstrateimmediate, often dramatic, improvements, some residual dysfunction or stunning

embo-is common Accurate right atrial and pulmonary artery pressures are critical andTEE is helpful Volume loading to a right atrial pressure of 15 to 25 cm ofwater and inotropic agents may be necessary If the pulmonary artery pressurehas normalized, we prefer dopamine, dobutamine, or low-dose epinephrine Thechronotropic effects of these agents may be beneficial in the stroke-volume-lim-ited, stunned right ventricle Persistent elevation of pulmonary artery pressuresmust be investigated and treated expeditiously Inadequate ventilation or oxygen-ation is sometimes the culprit and normal arterial blood gases should be docu-mented before weaning begins The heparin antagonist, protamine, is a knownpulmonary vasoconstrictor and should be administered cautiously The possibility

of residual or recurrent emboli should be considered and, if echocardiography

is suggestive, the pulmonary arteries should be reexplored Phosphodiesteraseinhibitors such as milrinone may be the ideal inotropic class of agents in thissetting but systemic vasodilatory effects may need to be counteracted with otheragents Inhaled nitric oxide or intravenous prostacyclin can be life-saving in se-vere cases

E Inferior Vena Caval Filters

The role of inferior vena caval (IVC) filters in pulmonary embolectomy is versial About two-thirds of the reports advocate IVC interruption to avoid theuncommon, but often fatal, complication of early recurrent embolization Thealternative, early anticoagulation with heparin, does not completely eliminate therisk and may increase postoperative bleeding complications, particularly in pa-tients with contraindications to thrombolytic therapy The immediate postopera-tive period, before heparin can be safely initiated, may also be the period of

contro-greatest risk for reembolization For these reasons, and from a personal ence with a fatal recurrent embolus, I believe most patients should undergo place-ment of an IVC filter The low, but finite, incidence of filter complications (IVCthrombosis with recurrent embolization, migration, and chronic venous stasis)must, however, be considered, especially in younger patients in whom their cu-mulative incidence can be significant over a lifetime.

experi-We usually place the filter in the operating room just prior to sternal closure

It is advanced through the right atrial appendage venous pursestring into the frarenal vena cava, guided by a portable ‘‘C-arm’’ fluoroscope Occasionally, astable patient who is already in the angiography suite for a pulmonary angiogramwill undergo preoperative filter placement if the procedure can be completedwith minimal delay Some centers transfer the fresh postoperative patient to theangiography suite on the way to the intensive care unit but this seems morecomplicated and potentially dangerous

in-F Postoperative Management

Right ventricular function may take several days to normalize, and aggressivesupport may be necessary during this period Right atrial and pulmonary arterypressure, cardiac output, and mixed venous oxygen saturation should be carefullymonitored Strict attention to adequate ventilation and oxygenation is critical toavoid even transient pulmonary vasoconstriction Inotropic agents should beweaned slowly If a prolonged wean is anticipated, adding milrinone can permitcatecholamines to be withdrawn If an IVC filter has been placed, postoperativeheparin can be delayed for 24 to 48 h and started gently, without a bolus, tomaintain a partial thromboplastin time of 50 to 60 s Warfarin can be initiated,with a target International Normalized Ratio (INR) or 2.0 to 2.5, once the patient

is able to take oral medications Long-term anticoagulation is usually continuedfor at least 6 months A baseline echocardiogram and quantitative ventilation-perfusion scan are performed prior to discharge and repeated at 6 months todocument resolution of any residual small perfusion defects and normalization

of right heart function

V RECENT BRIGHAM AND WOMEN’S HOSPITAL

EXPERIENCE

In the fall of 1999 we embarked on a multidisciplinary program at Brigham andWomen’s Hospital in Boston to improve our results with acute pulmonary embo-lectomy The team consisted of a single cardiologist and surgeon in close collabo-ration with interventional cardiology and radiology Our goal was to identify

candidates for surgical embolectomy soon after presentation by emphasizingrapid diagnosis and triage Our indications for embolectomy are similar to thosedescribed above and include all patients with large central pulmonary emboliwho have contraindications to thrombolysis, are in severe cardiogenic shock, orhave mobile right heart thromboemboli Once the patient has been selected forembolectomy, the team is committed to immediately transporting the patient tothe operating room.

Over an 8-month period, between October 1999 and May 2000, 12 tive patients (67% male; mean age 60.5 years) with acute major, central pulmo-nary embolism underwent surgical pulmonary embolectomy One patient hadundergone pulmonary thromboendarterectomy 2 months earlier and presentedwith recurrent embolization from inferior venal caval thrombosis above his filter

consecu-In another patient, the source of emboli was tumor thrombus extending into therenal vein and inferior vena cava from a large, previously undiagnosed left renalcell carcinoma A perfusion scan (5/12), spiral CT (6/12), pulmonary angiogram(2/12), and/or echocardiogram (4/10) confirmed the diagnosis One patient wasintubated on high-dose inotropic support Most of the remaining patients had had

a period of hypotension or syncope but responded well to volume or low-doseinotropic support Despite the fact that one-half of the patients were transferredfrom outside hospitals, the mean time from diagnosis to arrival in the operatingroom was 1.6 h

Four of the ‘‘hemodynamically stable’’ patients suffered a cardiac arrest

in the operating room requiring emergent institution of cardiopulmonary bypass.Normothermic cardiopulmonary bypass without aortic cross-clamping was insti-tuted Transesophageal echocardiography was performed in all patients and fourpatients with right atrial or inferior vena caval thromboemboli underwent rightatriotomy and clot extraction Pulmonary clot extraction was performed underdirect vision without any adjunctive maneuvers such as Fogarty balloon embolec-tomy The patient with renal cell carcinoma underwent nephrectomy with en blocinferior vena caval thrombectomy during a brief period of hypothermic circula-tory arrest prior to pulmonary embolectomy An IVC filter was placed before(3/12), during (5/12), or after surgery (2/12) in most patients

All patients were successfully weaned from cardiopulmonary bypass andleft the operating room in stable condition One patient, a 49-year-old morbidlyobese gentleman, who did not have an inferior vena caval filter, sustained multiplerecurrent emboli on the first postoperative day He ultimately succumbed to com-plications of heparin-induced thrombocytopenia despite repeat embolectomy,placement, and successful removal of a right ventricular assist device The opera-tive mortality was therefore 8.3% The patient with the recurrent embolizationafter thromboendarterectomy was discharged from the hospital after a prolonged

hospital course but died 2 months postoperatively of sepsis from C difficile

coli-tis The remaining 10 patients were discharged from the hospital are doing well

at home at a mean follow-up of 5 months

VI SUMMARY

Surgical pulmonary embolectomy has a definite role to play in the management

of selected patients with acute, major pulmonary embolism Rapid noninvasivediagnostic modalities allow proper patient selection based on anatomical location

of the emboli, right ventricular function, and contraindications to thrombolysis.Operative results are a direct reflection of the preoperative hemodynamic status,the degree of underlying cardiopulmonary disease, and attention to minimizingsurgical trauma and protecting the right heart An operative mortality of 10% orless and excellent long-term outcomes can be expected if the procedure is per-formed, prior to cardiovascular collapse, as part of a multidisciplinary strategythat emphasizes careful patient selection, rapid diagnosis, triage, and transport

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