CHAPTER 5 Ventral Herniorrhaphy
BACKGROUND
A variety of abdominal wall hernias (ventral hernias) are commonly treated by the general surgeon (Fig. 5-1). Umbilical hernias are common in young children; most close by 2 years of age, and repair is rarely considered before 5 years of age. Umbilical hernias in adults are most commonly acquired and typically develop in patients with elevated intra-abdominal pressure (e.g., from obesity, pregnancy, or ascites). Epigastric hernias are found in the midline, superior to the umbilicus, and are often small and multiple. Pain may result from incarceration of properitoneal fat. Spigelian hernias result from herniation at the lateral border of the rectus sheath (linea semilunaris). A bulge is rarely apparent because these hernias usually dissect behind the external oblique aponeurosis. Incisional hernias are a common complication of abdominal surgery, occurring after up to 10% of abdominal wall closures. Technical error (e.g., excessive tension on the abdominal closure and inadequate approximation of the fascial edges) is the major etiology. Factors that result in increased intra-abdominal pressure (e.g., obesity, pregnancy, and ascites) and compromise wound healing (e.g., malnutrition and immunosuppression) may be contributory.
INDICATIONS FOR VENTRAL HERNIA REPAIR
I. Reducible Hernias: Ventral hernias are associated with a small risk of incarceration (i.e., entrapment of the contents of a hernia within the fascial defect). Generally, small hernias are more likely to become incarcerated than are larger hernias. In patients without significant comorbidity, ventral hernias may be repaired electively to minimize this risk, to alleviate associated symptoms (e.g., discomfort), or to improve cosmesis. A role for observation of asymptomatic and minimally symptomatic hernias has emerged in patients with significant comorbidity and those willing to accept the small risk of incarceration.
II. Incarceration: Incarceration of bowel within a hernia may result in intestinal obstruction or compromise of the blood supply to the hernia contents (i.e., strangulation). Acute incarceration generally mandates urgent surgical intervention. In the absence of associated symptoms, chronically incarcerated ventral hernias may be managed expectantly.
PREOPERATIVE EVALUATION
I. History: Symptoms suggesting incarceration or intestinal obstruction (e.g., abdominal pain, nausea, vomiting, and constipation) and factors that may contribute to abdominal wall herniation (e.g., chronic cough, constipation, or previous abdominal surgery) should be elicited.
II. Physical Examination: The goals of the physical examination are: (1) to determine the size of the hernia defect, (2) to distinguish a true hernia from a diastasis, and (3) to distinguish a reducible hernia from an incarcerated hernia. In the patient with an acutely incarcerated hernia, signs consistent with strangulation should be elicited (e.g., focal abdominal tenderness or peritonitis).
III. Imaging: In the setting of an incarcerated ventral hernia, plain abdominal radiographs may show dilated bowel or air–fluid levels consistent with intestinal obstruction. Ventral hernias are often better assessed with a CT scan, which may help to characterize the contents of the hernia (e.g., bowel vs. fat), localize and delineate the degree of bowel obstruction in the setting of incarceration, or identify signs consistent with strangulation (e.g., bowel wall edema).
COMPONENTS OF THE PROCEDURE AND APPLIED ANATOMY
Ventral hernias may be repaired using a variety of approaches. Factors that influence the choice of approach include the size of the defect, the integrity of the abdominal wall fascia surrounding the hernia, and surgeon preference (Fig. 5-2).
Preoperative Considerations
I. Prophylactic antibiotics are indicated before elective repairs with mesh. The chosen antibiotic should have efficacy against skin flora (i.e., gram-positive organisms) and should be administered within 1 hour prior to incision.
Operative Repair
I. Types of Mesh: Most current approaches to ventral hernia repair involve placement of a mesh prosthesis. A variety of mesh types are available; each has distinct advantages and disadvantages.
A. Permanent synthetic: Polypropylene (Prolene), high-density polyethylene (Marlex), and coated PTFE (Gore-tex) are commonly used permanent synthetic mesh products. They are designed to serve as permanent structural components of the hernia repair and are incorporated into scar tissue over time. Because of associated risks of intra-abdominal adhesion and fistula formation, placement of uncoated mesh adjacent to the bowel should be avoided. The use of permanent mesh is contraindicated for the repair of acutely incarcerated or strangulated hernias because bacteria translocation resulting from bowel stasis, distention, and ischemia can lead to mesh infection. Similarly, infected mesh should not be replaced with a new permanent mesh prosthesis during reoperative hernia operations.
B. Bioprosthetic: Bioprosthetic mesh made out of materials such as collagen, porcine gut submucosa, or cadaveric dermis is increasingly being used. Bioprosthetics are more resistant to infection and are sometimes used despite contamination.
C. Nonpermanent synthetic: Nonpermanent synthetic mesh products, such as polyglactin (Vicryl), are sometimes used to reinforce hernia repairs in the setting of contamination. Alternatively, such products may be used as a temporary barrier against evisceration when the fascia cannot be approximated or when a wound is contaminated.
II. Open Primary Repair: Primary repair involves closure of the fascial defect without prosthetic mesh. This approach is generally reserved for cases in which the fascial defect is small (e.g., epigastric and umbilical hernias).
A. An incision is made to allow for complete exposure of the defect. Umbilical hernia repairs are often performed through a curvilinear horizontal or midline vertical incision. Epigastric hernias are usually repaired through a vertical midline incision.
III. Open Repair with Mesh Implant: In cases in which there is a large fascial defect, most surgeons elect to bolster the repair with mesh. Mesh may be secured anterior to the fascia (onlay), posterior to the fascia (inlay), or posterior to the rectus muscle within the rectus sheath (retrorectus). The retrorectus repair avoids potential pitfalls associated with onlay (e.g., mesh infection) and inlay (e.g., adhesion formation and fistula), but requires more extensive dissection and is generally more time consuming.
A. Onlay mesh repair
3. Several heavy nonabsorbable “U” stitches are placed through the mesh, into the fascia, and back through the mesh circumferentially around the defect. The sutures are left untied.
B. Inlay mesh repair
3. Several nonabsorbable sutures are used to affix the mesh to the posterior surface of the fascia. Sutures are thrown through the fascia and then through the mesh and are brought back out through the fascia circumferentially around the fascial defect. The sutures are left untied. If possible, peritoneum is preserved to prevent subsequent adhesion formation between bowel and mesh.
C. Retrorectus repair (Fig. 5-3)
3. The rectus sheath on each side of the fascial defect is divided. This incision is extended vertically along the length of the rectus sheath. The rectus muscle is dissected off of the posterior sheath bilaterally.
D. Laparoscopic ventral hernia repair
1. Port placement is highly variable. Initially, port placement may be in the subxiphoid midline or along either costal margin at the anterior axillary line, where there are least likely to be adhesions to bowel. The port must be placed far enough from the fascial defect to allow for adequate visualization of the hernia on insertion of the laparoscope. Because most patients have had previous surgery, an “open” technique for port insertion is generally preferred. Additional ports are placed as needed.
2. Adhesions to the anterior abdominal wall are lysed using a combination of sharp and blunt dissection.
4. The mesh prosthesis is cut to size outside of the abdomen. The piece of mesh should be large enough to allow for 5-cm margins of overlap with the fascia in all directions. Four sutures are placed equidistant from each other around the perimeter of the mesh and are left untied. The mesh is marked for orientation, rolled into a cylinder, and inserted through the largest port. The mesh is unrolled in the abdomen and oriented for fixation.
5. Small incisions are made in four quadrants 5 cm beyond the perimeter of the hernia defect, corresponding to the sutures placed through the mesh. A suture-passing instrument is inserted through the fascia underlying each incision at two points several millimeters apart. With each pass, one end of the suture is retrieved and brought out through the corresponding incision. The two tails of each suture are then tied to fix the mesh behind the fascial defect. A tacker is used to fix the mesh to the anterior abdominal wall at multiple points between the sutures.
6. All ports are removed, the fascia at the camera port site is closed, and the skin incisions are closed.
COMPLICATIONS
I. Seromas are common after repairs of larger hernias involving the creation of subcutaneous flaps; drain placement is indicated in such cases. Seroma formation often complicates laparoscopic repairs as well. Reabsorbtion occurs over time, and intervention is usually unnecessary.
II. Surgical site infections are of particular concern after mesh hernia repairs and sometimes mandate reoperation and mesh removal.
III. Recurrence may result from technical error (e.g., excessive tension on the repair or inadequate mesh coverage). Factors that increase intra-abdominal pressure (e.g., obesity and ascites) or compromise wound healing (e.g., immunosuppression and malnutrition) may predispose to recurrence.
IV. The repair of very large ventral hernias, in which a significant portion of the abdominal contents is contained within the hernia sac (i.e., loss of domain), is associated with a unique set of complications. Replacement of the hernia contents within the abdominal cavity may result in greatly elevated intra-abdominal pressures. Abdominal compartment syndrome, characterized by cardiovascular compromise secondary to decreased venous return, elevated peak airway pressures, and end-organ hypoperfusion (e.g., renal failure and visceral ischemia), may ensue. Reoperation and release of the abdominal closure is required if abdominal compartment syndrome is suspected.
Berry MF, Paisley S, Low DW, Rosato EF. Repair of large complex recurrent incisional hernias with retromuscular mesh and panniculectomy. Am J Surg. 2007;194:199-204.
Malangoni MA, Gagliardi RJ. Hernias. In: Townsend CM, Beauchamp RD, Evers BM, Mattox KL, editors. Sabiston Textbook of Surgery: The Biological Basis of Modern Surgical Practice. 17th ed. Philadelphia: Saunders; 2004:1199-1218.
