Overview of abdominal wall hernias in adults

Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Official reprint from UpToDateđ www.uptodate.com â2017 UpToDate, Inc and/or its affiliates All Rights Reserved Overview of abdominal wall hernias in adults Author: David C Brooks, MD Section Editor: Michael Rosen, MD Deputy Editor: Wenliang Chen, MD, PhD All topics are updated as new evidence becomes available and our peer review process is complete Literature review current through: Nov 2017 | This topic last updated: Jan 21, 2017 INTRODUCTION — A hernia is a protrusion, bulge, or projection of an organ or part of an organ through the body wall that normally contains it, such as the abdominal wall They are typically classified by etiology and location Most abdominal wall hernias should be repaired when identified; however, there are exceptions (eg, parastomal hernia) The nature of the repair depends upon the size of the hernia and the location on the abdominal wall in which it has occurred An overview of the classification, clinical features, and treatment options for most abdominal wall hernias will be reviewed here More in-depth information for incisional hernias, inguinal and femoral hernias, parastomal hernias, and hernias related to peritoneal dialysis are discussed separately ● (See "Management of ventral hernias".) ● (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults" and "Overview of treatment for inguinal and femoral hernia in adults".) ● (See "Parastomal hernia".) ● (See "Abdominal hernias in continuous peritoneal dialysis".) CLASSIFICATION — Abdominal wall hernias are broadly classified according to the region of the abdominal wall in which they occur (figure 1): ● Ventral hernia – Ventral hernias occur anteriorly and include epigastric, umbilical, spigelian, parastomal, and most incisional hernias ● Groin hernia – The groin is the region at the lower margin of the abdomen where the thigh meets the hip Groin hernias include inguinal and femoral hernias Groin hernias are subclassified according to anatomic factors (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults".) ● Pelvic hernia – Pelvic hernias can protrude through the pelvic foramina, as with sciatic and obturator hernias, or through the pelvic floor as perineal hernias https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM ● Flank hernia – Flank hernias protrude through weakened areas of back musculature and include the superior and inferior lumbar triangle hernias Abdominal wall hernias can also be classified by etiology ● Congenital hernia – The defect in the abdominal wall is present from birth ● Acquired hernia – The defect develops as the result of a weakening or disruption of the fibromuscular tissues of the abdominal wall due to connective tissue abnormalities, abdominal wall trauma, or possibly drug effects CLINICAL FEATURES History — The patient's history may identify risk factors associated with hernia formation These are reviewed separately for the more common types of hernias (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults", section on 'Risk factors' and "Management of ventral hernias" and "Parastomal hernia", section on 'Risk factors'.) The clinical presentation of abdominal wall hernias can vary depending upon location Small hernias can be asymptomatic or present with varying degrees of pain and discomfort as the hernia contents protrude through the abdominal wall defect Most often, the patient will complain of a bulge somewhere in the abdominal wall Coughing or straining may aggravate any pain or discomfort (figure 2) Large ventral hernias can cause excessive pressure leading to areas of ischemia and ulceration which can be seen on the skin (image 1) A Richter's type hernia is a particular type of abdominal wall hernia for which only part of the circumference of the bowel becomes incarcerated in the hernia defect (image 2) [1] A Richter's type hernia can form anywhere a defect is large enough for the bowel to enter, but small enough to prevent protrusion of an entire loop of bowel [1] The most common site is in the femoral canal, where it can be easily mistaken for an enlarged lymph node These hernias can also develop at laparoscopic port sites The diagnosis of a Richter's hernia can be difficult [2] Focal strangulation of a portion of the bowel (figure 3) can progress to ischemia and gangrene, with or without overt signs of intestinal obstruction Patients may present initially with only local inflammation at the site of the hernia Richter's type hernia can also present in a delayed fashion as an enterocutaneous fistula Although any abdominal wall hernia can present with complications due to incarceration of intestinal contents in the defect, abdominal wall hernias such as femoral, obturator and sciatic hernias frequently go unrecognized until they present as bowel obstruction (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults", section on 'Incarceration and strangulation' and "Epidemiology, clinical features, and diagnosis of mechanical small bowel obstruction in adults" and "Overview of mechanical colorectal obstruction".) Physical findings — The abdominal wall should be examined with the patient both standing and lying down On examination, the hernia may be easy to identify, and if palpable, the edges of the fascial defect can often be defined Supine examination will often allow the size of the hernia defect to be determined The entire abdominal wall, particularly along the length of any incisions, should be palpated carefully to identify all coexistent hernia sites DIAGNOSIS — Most ventral and groin hernias can be readily identified with a thorough abdominal and groin https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM examination, but there is a subset of patients with very small hernias that are hidden in the abdominal fat planes These are best characterized using imaging studies [3] ● Ultrasound – epigastric, spigelian, groin, incisional, lumbar, umbilical ● Computed tomography – lumbar, obturator, perineal, sciatic In the obese patient with a suspected incisional hernia that cannot be confirmed on examination, abdominal CT is the best imaging study to confirm a diagnosis of abdominal wall hernia and identify the contents contained within the hernia sac DIFFERENTIAL DIAGNOSIS — Although any intra-abdominal pathology that can cause abdominal pain and discomfort, most will be accompanied by elements of the history and other symptoms and signs The differential of acute abdominal pain and chronic abdominal wall pain is reviewed elsewhere (See "Causes of abdominal pain in adults" and "Anterior cutaneous nerve entrapment syndrome".) Abdominal wall masses that could mimic strangulated abdominal wall hernia include abdominal wall hematoma and abdominal wall tumors ● Abdominal wall hematoma generally occurs in the presence of antithrombotic therapy with or without instrumentation (eg, paracentesis) ● Desmoid tumors, which can arise from the abdominal muscular aponeurosis are characterized by slow growth and minimal pain, and are associated with a different risk profile Likewise, abdominal wall sarcomas can similarly present as an abdominal wall mass (See "Desmoid tumors: Epidemiology, risk factors, molecular pathogenesis, clinical presentation, diagnosis, and local therapy" and "Clinical presentation, histopathology, diagnostic evaluation, and staging of soft tissue sarcoma".) Diastasis recti is rarely confused for abdominal wall hernia The rectus muscles are normally fused at the midline with no more than to mm separating them Diastasis recti is an acquired condition in which the rectus muscles are separated by an abnormal distance along their length, but with no fascial defect A separation >2 mm is considered to be a diastasis recti (figure and figure 1) It is most commonly found in middle-aged and older men with central obesity, or small women who have carried a large fetus or twins to term [4] Incisional hernias are found in the presence of an obvious surgical incision Congenital or acquired midline hernias of the abdominal wall are confined to the umbilicus or the epigastrium Epigastric hernias are generally ≤2 cm in diameter SPECIFIC HERNIA SITES Epigastric hernia — Epigastric hernias are defects in the abdominal midline between the umbilicus and the xiphoid process (figure 1) The defects are often no more than cm in diameter (figure 5) [5] Epigastric hernias are likely the result of multiple factors, including congenitally weakened linea alba from a lack of decussating midline fibers, increases in intra-abdominal pressure, muscle weakness, or chronic abdominal wall strain The frequency of epigastric hernia is estimated to range from to percent in the general population and is more common in males (male:female = 3:1) It is most commonly diagnosed in middle age https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Epigastric hernia can be asymptomatic, but many times patients will note a small, slightly uncomfortable lump between the umbilicus and the xiphoid Up to 20 percent of epigastric hernias are multiple Bowel incarceration or strangulation is rare Epigastric hernias that involve a peritoneal sac usually contain only omentum, and only rarely small intestine Laparoscopically, these hernias can be difficult to identify due to the lack of peritoneal protrusion through the hernia defect Repair of the epigastric hernia is reserved for symptomatic patients, and most often can be performed as a daysurgery procedure under local anesthesia A small midline or transverse incision is made overlying the hernia The hernia contents are either reduced or resected, and the defect is closed with interrupted sutures Recurrence is uncommon Incisional hernia — Incisional hernias, by definition, develop at sites where an incision has been made for some prior abdominal procedure The epidemiology, risk factors, and management of incisional hernia are reviewed elsewhere (See "Management of ventral hernias".) It is estimated that an incisional hernia will develop in approximately 10 to 15 percent of abdominal incisions [6,7], and in up to 23 percent of patients who develop postoperative wound infection [8] Any condition that inhibits natural wound healing will make a patient susceptible to the development of an incisional hernia Such conditions include: infection, obesity, smoking, medications such as immunosuppressives, excessive wound tension, malnutrition, fractured sutures, poor technique, and connective tissue disorders [9] Emergency surgery increases the risk of incisional hernia formation Abdominal wound dehiscence, in particular, leads to incisional hernia Risk factors for the development of wound dehiscence include age >70 years, male gender, chronic pulmonary disease, ascites, jaundice, anemia, emergency surgery, coughing, type of surgery, and wound infection [10] (See "Complications of abdominal surgical incisions", section on 'Fascial dehiscence'.) Postoperative ventral hernias have been described following paramedian, subcostal, McBurney, Pfannenstiel, and flank incisions Laparoscopic port sites may also develop hernia defects in the abdominal wall fascia The highest incidence is seen with midline incision, the most common incision for many abdominal procedures [8] Upper abdominal incisions have a higher incidence of herniation than lower abdominal incisions A small, randomized trial comparing vertical and transverse incisions for abdominal aortic aneurysm repair found, at fouryear follow-up, that incisional hernia was significantly more likely to occur with vertical laparotomy [11] Incisional hernias typically develop in the early postoperative period, suggesting that local factors (infection, tension, technique) are responsible However, hernias can develop as late as 10 years after surgery; these may arise from previously undetected small hernias Incisional hernias can increase in size to enormous proportions; giant ventral hernias can contain a significant amount of small or large bowel At the extreme end of the spectrum is the giant incisional hernia that leads to loss of abdominal domain, which occurs when the intraabdominal contents can no longer lie within the abdominal cavity The patient with an incisional hernia complains of a bulge in the abdominal wall, originating deep to the skin scar This may cause a varying degree of discomfort, or may present as a cosmetic concern Symptoms are usually aggravated by coughing or straining, as the hernia contents protrude through the abdominal wall defect (figure 2) Presentation of the incisional hernia with incarceration causing bowel obstruction is not uncommon In large ventral hernias, the skin may present with ischemic or pressure necrosis leading to frank ulceration (image 1) https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM The hernia, on examination, is usually easy to identify, and the edges of the fascial defect can often be defined by palpation The entire abdominal wall, along the length of the incision, should be inspected and palpated carefully, as multiple hernias are often present in the setting of an incisional hernia These are frequently referred to as "swiss cheese hernias" because of their appearance In the obese patient with a suspected incisional hernia that cannot be confirmed on examination, computed tomography of the abdomen is the best test to visualize intra-abdominal contents within the hernia sac (See 'Diagnosis' above.) Most incisional hernias should be repaired Surgery should be considered when any of the following factors are present: ● Symptoms attributable to the hernia ● Potential for bowel incarceration ● Sufficient size to complicate dressing or activities of daily living Even the smallest incisional hernia has the potential for incarceration and, thus, repair should be considered Hernias that are less likely to incarcerate include upper abdominal hernias, hernias less than one cm in diameter, and hernias larger than to cm (where loops of bowel can move in and out of the hernia sac without restriction, and are therefore less likely to become incarcerated) Contraindications to elective surgery are only those conditions that preclude any elective surgical procedure in the unstable or high-risk patient due to comorbidities (See "Evaluation of cardiac risk prior to noncardiac surgery".) Inguinal and femoral hernia — Groin hernias, including inguinal and femoral hernias, are the most common abdominal wall hernias Issues related to these types of hernias are discussed in detail elsewhere (See "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults" and "Overview of treatment for inguinal and femoral hernia in adults".) Lumbar hernia — Although lying outside of the abdominal wall anatomically, lumbar hernias are typically classified as a type of abdominal wall hernia The lumbar region is defined superiorly by the 12th rib, medially by the erector spinae muscle, inferiorly by the crest of the iliac bone, and laterally by the internal oblique muscle [12] Lumbar hernias arise in one of two possible triangular defects in the lumbar region (figure 6): ● The superior lumbar triangle (Grynfeltt) (image 3) is an inverted triangle, its base is the twelfth rib, its posterior border is the erector spinae, and its anterior border is the posterior margin of the external oblique; its apex is at the iliac crest inferiorly ● The inferior triangle (Petit) is located between the external oblique, the latissimus dorsi, and the iliac crest caudally (image 4) Lumbar hernias can be congenital or spontaneous, but most lumbar hernias are related to prior surgery, most typically urologic surgery such as partial or complete nephrectomy (image 5) Denervation of the nerves from urologic surgical approaches can aggravate an inherent weakness in the lumbar area The apparent hernia can https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM be an area of diastasis, in which the muscular aponeurosis has been weakened Traumatic injuries can also exacerbate inherent weaknesses [13] The most common presentation of a lumbar hernia is a palpable posterolateral mass that increases in size with coughing and strenuous activity [14] The mass is usually reducible, and disappears when the patient assumes a decubitus position [13] Lumbar hernias can also present as vague back pain, bowel obstruction, urinary obstruction, pelvic mass, or, rarely, as a retroperitoneal or gluteal abscess Repairs can be performed laparoscopically or via an open approach Invariably, repair requires the use of mesh The mesh can be placed deep to the muscular wall if the procedure is performed anteriorly through an open approach or adjacent to the defect if the hernia is repaired laparoscopically This repair can lead to chronic postoperative pain related to the difficulty in fixing mesh to the costal margin Obturator hernia — Obturator hernias are a rare type of abdominal wall hernia in which the abdominal contents protrude through the obturator foramen Weakening of the obturator membrane may result in enlargement of the canal with a defect that is usually anterior and medial to the obturator neurovascular bundle [15] Factors that increase intra-abdominal pressure are implicated as risk factors They are more commonly right sided, but can be bilateral These are much more common in women, usually in the setting of profound weight loss [16] A pilot tag or properitoneal fat precedes the development of a hernia sac The hernia sac usually contains small bowel, but may contain large bowel, omentum, fallopian tube, or appendix In >90 percent of cases, the diagnosis is made intraoperatively during exploration for bowel obstruction [15] It can also present as obturator neuralgia (groin pain radiating medially to the knee) due to compression of the obturator nerve, palpable proximal thigh mass (between pectineus and adductor longus muscles), or ecchymosis of the thigh if bowel necrosis has occurred Obturator hernias may be initially confused as femoral hernias, but can also occur in conjunction with femoral hernia Nonstrangulated obturator hernias can be repaired using mesh via a posterior preperitoneal approach (open or laparoscopic), which provides direct access to the hernia Reduction of the hernia may require incision of the obturator membrane When strangulation is suspected, an abdominal approach is used Parastomal hernia — Patients with a stoma (ileostomy, colostomy) are at risk for hernia formation due to creation of a defect in the abdominal wall through which the bowel is brought when constructing the stoma (See "Parastomal hernia" and "Routine care of patients with an ileostomy or colostomy and management of ostomy complications" and "Overview of surgical ostomy for fecal diversion".) Perineal hernia — Perineal hernias are hernias that protrude through the pelvic floor Primary perineal hernias are rare and most occur following surgery Perineal hernia occurring after rectal resection is reviewed separately (See "Management of perineal complications following an abdominal perineal resection", section on 'Perineal hernia'.) Primary perineal hernias most commonly occur in older, multiparous women Clinically, they present as a unilateral bulge in the area of the labia, perineal regions, or gluteal regions They are classified as anterior or posterior based upon the position relative to the transverse perinei muscle [15] The hernia may be detected on bimanual rectal-vaginal examination and can be confirmed on ultrasound or pelvic computed tomography (CT) Sciatic hernia — Sciatic hernias pass through either the greater sciatic foramen above (suprapiriform hernia) or below (infrapiriform hernia) the pyriformis muscle, or through the lesser sciatic foramen (spinotuberous hernia) https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM (figure 7) These hernias are rare Conditions that may predispose to sciatic hernia include coexisting hernia, malignancy, pelvic abnormalities (eg, congenital, posttraumatic), and pelvic surgery [17] In one review, the contents of the hernia sac were (in order of frequency) ovary, ureter, small intestine, colon, neoplasm, omentum, or bladder [17] These unusual hernias may present as a buttock mass, with abdominal pain, or as sciatica Intestinal obstruction, urinary sepsis due to herniation of the ureter, and gluteal sepsis have also been reported A definitive diagnosis can be made with computed tomography or magnetic resonance imaging Repair consists of reduction of the hernia contents and closure of the defect with or without prosthetic material, and can be accomplished using an abdominal approach (typically laparoscopic) for strangulated hernias, a transgluteal approach (nonstrangulated), or a combined approach Spigelian hernia — A Spigelian hernia occurs along the semilunar line (figure 8), which is the caudal most extent of the posterior rectus sheath [18] This anatomic location is weak because of the absence of a posterior sheath behind the rectus muscle Spigelian hernia is well described, but relatively rare It is likely that these hernias will become more frequently diagnosed, as they are readily seen on computed tomography scans as well as laparoscopic views of the anterior abdominal wall As the hernia develops, preperitoneal fat emerges through the defect in the Spigelian fascia, bringing an extension of the peritoneum with it through the fascia The hernia is nevertheless covered by the intact external oblique aponeurosis For this reason, almost all Spigelian hernias are interparietal in nature, and only rarely will the hernia sac lie in the subcutaneous tissues anterior to the external oblique fascia The hernia cannot develop medially due to resistance from the intact rectus muscle and sheath Therefore, a large Spigelian hernia is most often found lateral and inferior to its defect in the space directly posterior to the external oblique muscle Accurate diagnosis of Spigelian hernias by physical examination is quite challenging The patient most often presents with a swelling in the mid to lower abdomen, just lateral to the rectus muscle The patient may complain of a sharp pain or tenderness at this site The hernia is usually reducible in the supine position The reducible mass may be palpable, even if it is below the external oblique musculature Up to 20 percent of Spigelian hernias will present incarcerated Ultrasound is the most reliable and easiest imaging modality to assist in the diagnostic workup [19] Even if the hernia is fully reduced during examination and no mass is palpable, ultrasound can show a break in the echogenic shadow of the semilunar line associated with the fascial defect Ultrasound can also identify the nonreduced hernia sac passing through the defect in the Spigelian fascia Computed tomography scanning of the abdomen will also confirm the presence of a Spigelian hernia [20] The anatomy of the Spigelian hernia should make it readily apparent on laparoscopic evaluation of the anterior abdominal wall (image and image 7) Given the frequency of bowel obstruction, repair is generally recommended once the hernia is diagnosed Surgery is usually performed under general anesthesia A transverse incision is made directly over the palpable mass or fascial defect A hernia in the subcutaneous space will be immediately obvious, whereas an interparietal hernia will require deeper dissection The external oblique muscle is split to identify the sac posterior to it The sac is isolated, opened, and the contents reduced The sac can be excised or inverted depending upon its size The defect is closed by suturing the medial and lateral edges of the internal oblique and transversus abdominis https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM aponeuroses, which approximates the internal oblique and transverses fascia laterally to the rectus sheath medially [21] Although the use of mesh plugs to close the hernia defect has been described, prosthetic mesh is not required for this repair Laparoscopic repair has also been performed successfully, following previously described techniques for incisional hernia [22] Recurrence is uncommon Umbilical hernia — Congenital umbilical hernias in children are discussed separately (See "Care of the umbilicus and management of umbilical disorders".) In adults, umbilical hernias are more often acquired and are associated with increased intra-abdominal pressure due to obesity, abdominal distension, ascites, and pregnancy They occur more commonly in females than in males with a to ratio In men, umbilical hernias most often present incarcerated, whereas females, particularly those close to their ideal body weight, are more likely to have an easily reducible mass Typically, omentum or preperitoneal fat is contained within the hernia sac Omental strangulation within a hernia can cause chronic abdominal wall pain On the other hand, if a knuckle of bowel becomes incarcerated (Richter's hernia), bowel obstruction or bowel ischemia can develop The diagnosis of umbilical hernia is usually made with palpation of a soft mass at the umbilicus, which may be asymmetric, located slightly above, slightly below, or to one side or another (picture 1) Tenderness can be elicited with pressure and palpation, but is often not present without provocation Certain umbilical hernias may be so small and asymptomatic that the patient is not even aware that a hernia is present These hernias not require repair and can be observed The treatment of symptomatic umbilical hernias is surgical, either as an open repair through a skin incision, typically for small hernias, or laparoscopically for large hernias For open repair, a vertical or curvilinear incision can be made overlying or adjacent the hernia sac, identifying the hernia sac and dissecting it to its fascial attachments Once the fascia has been cleared, the hernia sac can either be inverted or excised, and the fascia subsequently closed with a nonabsorbable suture (figure 9) If the defect is large, and the fascial edges cannot be approximated without tension, mesh should be used The mesh should be placed deep to the fascia (sublay technique) and sutured circumferentially to the surrounding umbilical fascia to prevent migration A variety of flat meshes and mesh plugs are available [23] An effort should be made to tack the skin of the umbilicus to the fascia to recreate a cosmetically appealing umbilicus INFORMATION FOR PATIENTS — UpToDate offers two types of patient education materials, "The Basics" and "Beyond the Basics." The Basics patient education pieces are written in plain language, at the 5th to 6th grade reading level, and they answer the four or five key questions a patient might have about a given condition These articles are best for patients who want a general overview and who prefer short, easy-to-read materials Beyond the Basics patient education pieces are longer, more sophisticated, and more detailed These articles are written at the 10th to 12th grade reading level and are best for patients who want in-depth information and are comfortable with some medical jargon Here are the patient education articles that are relevant to this topic We encourage you to print or e-mail these topics to your patients (You can also locate patient education articles on a variety of subjects by searching on "patient info" and the keyword(s) of interest.) ● Basics topic (see "Patient education: Abdominal wall hernias (The Basics)") https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM SUMMARY AND RECOMMENDATIONS ● A hernia is a protrusion, bulge, or projection of an organ or part of an organ through the body wall that normally contains it, such as the abdominal wall They are typically classified by region of the abdominal wall and etiology (See 'Classification' above.) ● Although abdominal wall hernias can go unnoticed, patients will usually complain of a bulge that may or may not be associated with other symptoms, most often localized pain However, abdominal wall hernia can present with complications related to incarceration and strangulation of contents in the hernia sac Large ventral hernias may present with skin ulceration due to pressure necrosis (See 'Clinical features' above.) ● The diagnosis of suspected abdominal wall hernia can usually be made with physical examination For patients in whom abdominal wall hernia is suspected but not apparent clinically, we suggest further imaging, the nature of which depends upon the location of the suspected hernia The differential diagnosis of abdominal wall hernia includes anything that may produce an abdominal wall mass such as abdominal wall hematoma or tumor, as well as other processes that produce abdominal pain and discomfort, or can lead to bowel obstruction (See 'Diagnosis' above and 'Differential diagnosis' above.) ● Specific hernia sites have characteristic features, which are summarized above, or in separate topic reviews: • Epigastric hernia (see 'Epigastric hernia' above) • Incisional hernia (see "Management of ventral hernias") • Inguinal and femoral hernia (see "Classification, clinical features, and diagnosis of inguinal and femoral hernias in adults") • Lumbar hernia (see 'Lumbar hernia' above) • Obturator hernia (see 'Obturator hernia' above) • Parastomal hernia (see "Parastomal hernia") • Perineal hernia (see 'Perineal hernia' above) • Sciatic hernia (see 'Sciatic hernia' above) • Spigelian hernia (see 'Spigelian hernia' above) • Umbilical hernia (see 'Umbilical hernia' above) Use of UpToDate is subject to the Subscription and License Agreement REFERENCES Steinke W, Zellweger R Richter's hernia and Sir Frederick Treves: an original clinical experience, review, https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM and historical overview Ann Surg 2000; 232:710 Kadirov S, Sayfan J, Friedman S, Orda R Richter's hernia a surgical pitfall J Am Coll Surg 1996; 182:60 Murphy KP, O'Connor OJ, Maher MM Adult abdominal hernias AJR Am J Roentgenol 2014; 202:W506 Ranney B Diastasis recti and umbilical hernia causes, recognition and repair S D J Med 1990; 43:5 Lang B, Lau H, Lee F Epigastric hernia and its etiology Hernia 2002; 6:148 Mudge M, Hughes LE Incisional hernia: a 10 year prospective study of incidence and attitudes Br J Surg 1985; 72:70 Kingsnorth A, LeBlanc K Hernias: inguinal and incisional Lancet 2003; 362:1561 Bucknall TE, Cox PJ, Ellis H Burst abdomen and incisional hernia: a prospective study of 1129 major laparotomies Br Med J (Clin Res Ed) 1982; 284:931 George CD, Ellis H The results of incisional hernia repair: a twelve year review Ann R Coll Surg Engl 1986; 68:185 10 van Ramshorst GH, Nieuwenhuizen J, Hop WC, et al Abdominal wound dehiscence in adults: development and validation of a risk model World J Surg 2010; 34:20 11 Fassiadis N, Roidl M, Hennig M, et al Randomized clinical trial of vertical or transverse laparotomy for abdominal aortic aneurysm repair Br J Surg 2005; 92:1208 12 Moreno-Egea A, Baena EG, Calle MC, et al Controversies in the current management of lumbar hernias Arch Surg 2007; 142:82 13 Orcutt TW Hernia of the superior lumbar triangle Ann Surg 1971; 173:294 14 Liang TJ, Tsai CY Images in clinical medicine Grynfeltt hernia N Engl J Med 2013; 369:e14 15 Salameh JR Primary and unusual abdominal wall hernias Surg Clin North Am 2008; 88:45 16 Stamatiou D, Skandalakis LJ, Zoras O, Mirilas P Obturator hernia revisited: surgical anatomy, embryology, diagnosis, and technique of repair Am Surg 2011; 77:1147 17 Losanoff JE, Basson MD, Gruber SA, Weaver DW Sciatic hernia: a comprehensive review of the world literature (1900-2008) Am J Surg 2010; 199:52 18 Skandalakis PN, Zoras O, Skandalakis JE, Mirilas P Spigelian hernia: surgical anatomy, embryology, and technique of repair Am Surg 2006; 72:42 19 Mufid MM, Abu-Yousef MM, Kakish ME, et al Spigelian hernia: diagnosis by high-resolution real-time sonography J Ultrasound Med 1997; 16:183 20 Shenouda NF, Hyams BB, Rosenbloom MB Evaluation of Spigelian hernia by CT J Comput Assist Tomogr 1990; 14:777 21 Larson DW, Farley DR Spigelian hernias: repair and outcome for 81 patients World J Surg 2002; 26:1277 22 Moreno-Egea A, Carrasco L, Girela E, et al Open vs laparoscopic repair of spigelian hernia: a prospective randomized trial Arch Surg 2002; 137:1266 23 Halm JA, Heisterkamp J, Veen HF, Weidema WF Long-term follow-up after umbilical hernia repair: are there risk factors for recurrence after simple and mesh repair Hernia 2005; 9:334 Topic 3688 Version 22.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 10 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Richters hernia on computed tomography The CT scan shows a Richter's hernia with a knuckle of part of the small bowel protruding into a hernia of the anterior abdominal wall CT: computed tomography Graphic 88742 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 15 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Richter's hernia Schematic diagram showing a Richter's hernia, in which the antimesenteric border, but not the whole wall, of the bowel is incarcerated Reproduced with permission from: Mulholland MW, Lillemoe KD Greenfield's Surgery: Scientific Principles And Practice, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 58994 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 16 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Diastasis recti Diastasis recti occurs when bowel protrudes through a separation between the two rectus abdominis muscles It appears as a midline ridge The bulge may appear only when client raises head or coughs The condition is of little significance Reproduced with permission from: Weber J, Kelley J Health Assessment in Nursing, Second Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 69049 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 17 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Epigastric hernia An epigastric hernia occurs when bowel protrudes through a weakness in the linea alba The small bulge appears midline between the xiphoid process and the umbilicus It may be discovered only on palpation Reproduced with permission from: Weber, J, Kelley, J Health Assessment in Nursing, Second Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 72710 Version 1.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 18 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Lumbar triangles The superior lumbar triangle (Grynfeltt) is an inverted triangle The base is the twelfth rib, the posterior border is the erector spinae, the anterior border is the posterior margin of the external oblique, and the apex is the iliac crest inferiorly The inferior triangle (Petit) is located between the external oblique, the latissimus dorsi, and the iliac crest Graphic 81616 Version 3.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 19 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Lumbar hernia through the superior triangle Note the multiple bony anomalies Reproduced with permission from: Eisenberg, RL Clinical Imaging: An Atlas of Differential Diagnosis, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 65959 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 20 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Lumbar hernia through the inferior triangle Reproduced with permission from: Eisenberg, RL Clinical Imaging: An Atlas of Differential Diagnosis, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 71107 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 21 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM CT lumbar hernia Computed tomogram of a left-sided lumbar hernia following nephrectomy for renal cell cancer CT: computed tomography Reproduced with permission from: Mulholland, MW, Lillemoe, KD Greenfield's Surgery: Scientific Principles And Practice, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 76449 Version 5.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 22 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Gluteal and sciatic hernias Sciatic hernias are rare The hernia can pass through the greater sciatic foramen above (1) or below (2) the pyriformis muscle or through the lesser sciatic foramen medial to the sciatic nerve Reproduced with permission from: Mulholland MW, Lillemoe KD Greenfield's Surgery: Scientific Principles And Practice, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 53186 Version 3.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 23 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Spigelian hernia Spigelian hernia A) Usual site of occurrence B) Transverse section of abdominal wall showing site of defect Reproduced with permission from: Mulholland, MW, Lillemoe, KD Greenfield's Surgery: Scientific Principles And Practice, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 55169 Version 1.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 24 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Spigelian hernia Small bowel is trapped in the hernia sac (arrow), which arises along the left semilunar line Reproduced with permission from: Eisenberg, RL Clinical Imaging: An Atlas of Differential Diagnosis, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 68967 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 25 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Spigelian hernia Herniation of fat through a defect in the aponeurosis between the left rectus abdominis (arrow) and the aponeurosis of the left transversus abdominis and internal oblique muscles The lateral margin of the hernia sac is the external oblique muscle and fascia (arrowhead) Reproduced with permission from: Eisenberg, RL Clinical Imaging: An Atlas of Differential Diagnosis, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2003 Copyright © 2003 Lippincott Williams & Wilkins Graphic 63214 Version 3.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 26 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Umbilical hernia Reproduced with permission from: Berg, D, Worzala, K Atlas of Adult Physical Diagnosis Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 72970 Version 2.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 27 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Umbilical hernia repair Repair of an umbilical hernia A) Diagram of longitudinal section through the hernia B) Subumbilical "smile" incision The hernial sac is excised C) Waistcoat type of closure Reproduced with permission from: Mulholland, MW, Lillemoe, KD Greenfield's Surgery: Scientific Principles And Practice, Fourth Edition Philadelphia: Lippincott Williams & Wilkins, 2006 Copyright © 2006 Lippincott Williams & Wilkins Graphic 53945 Version 1.0 https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 28 of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17, 9)25 AM Contributor Disclosures David C Brooks, MD Nothing to disclose Michael Rosen, MD Grant/Research/Clinical Trial Support: WL Gore; Miromatrix [Mesh (Mesh)] Speaker's Bureau: WL Gore; Bard [Mesh (Mesh)] Consultant/Advisory Boards: Artiste Medical [Mesh (Mesh)] Employment: Medical Director of AHSQC (Americas Hernia Society Quality Collaborative) Wenliang Chen, MD, PhD Nothing to disclose Contributor disclosures are reviewed for conflicts of interest by the editorial group When found, these are addressed by vetting through a multi-level review process, and through requirements for references to be provided to support the content Appropriately referenced content is required of all authors and must conform to UpToDate standards of evidence Conflict of interest policy https://www.uptodate.com/contents/overview-of-abdominal-wall-herni…search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page 29 of 29 ... strangulated abdominal wall hernia include abdominal wall hematoma and abdominal wall tumors ● Abdominal wall hematoma generally occurs in the presence of antithrombotic therapy with or without instrumentation... factors, including congenitally weakened linea alba from a lack of decussating midline fibers, increases in intra -abdominal pressure, muscle weakness, or chronic abdominal wall strain The frequency of. .. https://www.uptodate.com/contents /overview- of- abdominal- wall- herni…?search=inguinal%20hernia&source=search_result&selectedTitle=9~100 Page of 29 Overview of abdominal wall hernias in adults - UpToDate 12/26/17,