Ventral Hernia – Laparoscopic Repair

Laparoscopic Operative Method

Some of the principles of retrorectus prosthetic reinforcement have been adapted for laparoscopic ventral hernia repair. Instead of applying the mesh in a preperitoneal position, an intraperitoneal underlay with wide coverage of the hernia defect is performed. The mesh is secured in position with transfascial sutures and metallic staples or tacks. This technique also takes advantage of Pascal's principle of hydrostatics to provide a secure hernia repair; however, it typically does not include closure of the fascial defect and reconstruction of the abdominal wall. Based on these limitations, laparoscopic ventral hernia repair might not be the ideal approach for larger, complex defects.

Laparoscopic ventral hernia repair is usually performed with a 30- or 45-degree angled laparoscope. A minimal number of laparoscopic bowel graspers, dissectors, scissors, and blunt graspers are also necessary. Currently, 5-mm fixation devices (spiral titanium or absorbable tacks) are commonly used. A suture-passing device (W. L. Gore and Associates, Flagstaff, Ariz) is used for full-thickness trans­abdominal wall sutures. This approach requires the placement of an intraperitoneal prosthetic to be in contact with the viscera. Numerous prosthetic meshes have been designed to be placed in the intraperitoneal position and take advantage of anti-adhesive barriers on one side of the mesh.

The first step of a laparoscopic ventral hernia repair requires the establishment of a pneumoperitoneum. This can be done safely using either an open abdominal access technique, Veress needle, or optical viewing trocar. A window of access between the costal margin and the iliac crest on one side or the other is usually present and occurs even in a multiply operated abdomen. After inserting the first trocar, the abdominal cavity is viewed, and under direct visualization, additional trocars are placed as far laterally as possible. Usually, three trocars are placed on the operative side for an inline view and a two-handed technique for dissection and mesh deployment and fixation. An additional trocar or two on the contralateral side is occasionally required.

The most difficult and time-consuming portion of the procedure is adhesiolysis. Rare but serious complications from this procedure are related to bowel injury; therefore, meticulous dissection technique must be used. Sharp dissection should be performed as much as possible to avoid thermal spread from electrothermal (cautery) and ultrasonic energy. Small bowel injuries during adhesiolysis can be catastrophic, especially if they are missed. Enterotomy has been reported in an average of 1.7% to 3.3% of patients in recent series of laparoscopic ventral hernia repair. If an enterotomy occurs, the mortality rate is reported to be 1.7% if it is recognized and repaired. However, if the enterotomy is missed, the mortality rate increases to 7.7%. Management of a recognized intraoperative enterotomy varies according to the type and extent of the injured intestine and the type of mesh available. Small lacerations in the small intestine or bladder without significant contamination may not be an absolute contraindication to mesh placement either laparoscopically or by open means. In the event of fecal spillage, the bowel should be repaired and the adhesiolysis completed. A delayed hernia repair is generally warranted if a prosthetic is required. The patient is usually placed on a regimen of antibiotics and returned to the operating room in 3 or 4 days for definitive repair if there are no signs of infection, or the procedure may be aborted altogether. Other options include primary repair of the hernia defect with the anticipated higher recurrence rate, or repair with a biologic mesh (although the long-term durability of these repairs remains to be evaluated). Placement of synthetic mesh in the presence of significant contamination is contraindicated.

The hernia defect must be measured to correctly size the mesh prosthesis. This may be accomplished either externally or internally. If the hernia margins are measured externally, the abdomen should be desufflated to more accurately delineate the actual size of the hernia; if not, a thick abdominal wall or large hernia can result in overestimation of the mesh needed to fix the hernia. Measuring the hernia internally is performed with a disposable plastic ruler that is brought through a trocar into the abdomen. The length and width of the hernia defect are determined inside the abdominal cavity utilizing spinal needles as a guide. In this manner, the size of the hernia can be very accurately measured. Whether obtained inside or outside the abdomen, these measurements are used to choose an appropriately sized prosthetic mesh that will overlap all margins of the defect by at least 4 cm.

Four nonabsorbable size 0 monofilament or ePTFE sutures (approximately 30 cm in length) are placed at the midpoint of each side ( Figure 7-1-1 ). Exit sites for the sutures are predetermined on the abdominal wall and are marked 4 cm or more beyond the margin of the hernia. The mesh is rolled like a scroll from the superior and inferior ends, and is compressed and pulled (or pushed) into the peritoneal cavity through a 10-mm port site. The mesh is unfurled within the abdomen. The sutures are individually pulled through the abdominal wall with a suture passer at the previously marked positions. The individual strands of each suture are brought out through separate fascial punctures but through the same skin incisions so that full-thickness abdominal wall “bites” are taken to secure the mesh in position ( Figure 7-1-2 ). The initial marked sites may need to be modified further radially to allow for taut placement of the mesh. It is important that the mesh be taut when the abdomen is insufflated to avoid mesh buckling and excessive bulging. The sutures are individually tied with the knots left buried in subcutaneous tissue. The perimeter of the mesh is then secured with spiral tacks or staples placed 1 cm or so apart. The tacks are positioned close to the mesh edge to prevent infolding of the mesh and exposure of the rough, woven side to bowel (see Figure 7-1-2 ). The ideal number of sutures remains controversial. For small hernias or Swiss cheese-type defects, four sutures are likely sufficient. For larger central defects in obese patients, more sutures are typically advisable. Additional full-thickness, nonabsorbable sutures are placed in the mesh every 4 to 7 cm circumferentially with the suture passer if necessary. The tacks ensure that bowel will not herniate between the sutures. They do add some security to the repair but do not provide enough strength to serve as the only points of fixation. Recognizing this, several absorbable fixation devices are currently available. Little data exist showing a reduction in pain or change in recurrence rates associated with these absorbable fixation devices. Drains are traditionally not used for laparoscopic repairs.

As more emphasis is placed on recreating a functional abdominal wall, surgeons have investigated ways to reapproximate the rectus muscles in the midline via a minimally invasive approach. Although there is little more than case reports describing this technique, it involves placing interrupted figure-of-eight sutures with a suture passer through the displaced rectus. After placing enough sutures for the size of the defect (usually three to four), they are brought together under tension and tied bringing the defect back together in the midline. The defect is then reinforced with an intraperitoneal piece of mesh similar to standard laparoscopic ventral hernia repair. Typically, this mesh is sized as if the defect were left open. Undersizing the mesh might result in early reherniation if the defect is closed under excessive tension. Other authors have incorporated an endoscopic component separation to reduce tension on the midline closure for larger defects. To date, only small series have evaluated this method in terms of hernia recurrence, but it brings together the principles of minimally invasive hernia repair and recreating a functional abdominal wall.