Plate 204

Ventral hernias in the anterior abdominal wall include both spontaneous (e.g., umbilical, epigastric, and spigelian) and, most commonly, incisional hernias after an abdominal operation. Small ventral hernias less than 2½ cm in diameter are often successfully closed with primary tissue repairs. However, larger ones have a recurrence rate of up to 30 or 40 percent when a tissue repair alone is performed. It is estimated that 2 to 10 percent of all abdominal operations result in an incisional hernia. This explains the predominance of such hernias. Fortunately, the use of mesh has revolutionized the repair of abdominal wall hernias. Anterior placement of polypropylene mesh as an onlay to the primary repair is helpful and a retrorectus muscle placement is even better. However, the development of dual-sided mesh has allowed for an improved placement of mesh behind the abdominal wall and the hernial defect. These meshes present an intraperitoneal nonadherent surface (expanded polytetrafluoroethylene, or PTFE) to the bowel and an open polypropylene mesh grid or screen for adherence and incorporation into the peritoneum and posterior abdominal wall fascia. The dual-sided meshes can be placed laparoscopically for almost any ventral hernia, but extremely large hernias with loss of abdominal domain or those associated with extensive, dense intra-abdominal adhesions (e.g., peritoneal dialysis, prior peritonitis) are relative contraindications. The meshes are very expensive; however, operating room time and hospital length of stay are shortened. The laparoscopic incisions cause less pain and there is a faster return to normal activities or work. Finally, laparoscopic repair enables the detection and repair of multiple defects—a common finding in midline incisional hernias.

The patient must be free of infections, especially in the skin. Respiratory function should be optimized with cessation of smoking and appropriate pulmonary function evaluation. If bowel is contained with the hernia, endoscopic visualization, contrast studies, or imaging may be performed and the patient may be given a bowel preparation with a liquid diet and cathartics for 1 or 2 days prior to surgery. The major factors in the occurrence of this hernia, as well as the preceding operative note, should be reviewed.

General anesthesia with an endotracheal tube is required.

The patient is placed in a supine position with a pillow placed to produce mild flexion of the hips and knees. This helps to relax the abdominal wall. For ventral hernias that are not midline, the patient may be positioned with pillows for some lateral elevation of the chest, flank, and hips.

The patient is given perioperative antibiotics. An orogastric tube is passed for gastric decompression. A Foley catheter is placed and pneumatic sequential stockings are applied. The skin is prepared in the routine manner.

The 10-mm videoscope port (0) and the 5-mm operating ports (X) are a function of the position of the hernial defect and the preference of the surgeon (Figure 1A). The general principle is that of triangulation. The ports should be about a hand's breadth or more apart from each other and the two operating ports should be placed as widely apart as possible. Typical hernias and the placement of ports are shown (Figure 1B to E). One of the operating ports should be 10 mm in size if a 5-mm videoscope is not available.

The videoscope port is placed first, using the open Hasson technique (Plate 91). After the abdomen is entered safely and the Hasson port secured with the lateral stay sutures, the intraperitoneal space is inflated with carbon dioxide. The surgeon sets the gas flow rate and the maximum pressure (≤15 mmHg). The rising intra-abdominal pressure and total volume of gas infused is observed as the abdomen and hernia distend. The videoscope is white-balanced and focused. The optical end, usually a flat or zero-degree angle, is coated with antifog solution and the scope is advanced down the port into the abdomen under direct vision. All four quadrants of the abdomen are explored visually. The hernia and its contents are evaluated and additional unrecognized incisional hernial defects may be found, especially in long midline incisions. Omental and other adhesions to the abdominal and anterior abdominal wall about the hernial defect are visualized. A zone of about 4 to 6 cm must be made clear about the rim of the hernial defect for the wide attachment of the mesh beyond the borders of the actual defect.

Placement of the operating ports begins with the infiltration of the skin with a long-acting local anesthetic. The local needle may be passed perpendicularly full-thickness through the abdominal wall and its entry site verified with the videoscope. The skin is incised and the subcutaneous tissues are dilated with a small hemostat. The abdominal wall is transilluminated with the videoscope to show any regional vessels within the abdominal musculature. The 5-mm operating ports are placed, with visualization of their clean entry into the intraperitoneal space.

In the typical ventral or incisional hernia, the omentum will have formed some adhesions to the sac of the hernia. The omentum is grasped near the abdominal wall with the forceps or the dissecting instrument and gentle traction is applied. Using laparoscopic scissors, the surgeon sharply incises the junction of the omentum with the peritoneum of the abdominal wall (Figure 2). After each cut, a sweeping motion in the same area will open up the next zone for cutting. Minimal bleeding occurs. Electrocautery or other heat-generating coagulating systems should be used sparingly and only with full visualization so as to minimize the chance of thermal injury to the bowel. Extensive dense adhesions, inability to reduce the hernial contents from the sac, or an enterotomy that is not easily repaired all require conversion to an open laparotomy and repair. After the abdominal wall adhesions are taken down, the omentum is removed from the hernial sac, which is left intact. A useful maneuver is the inversion of the hernial sac using several fingers externally (Figure 3). This allows the sharp cutting to continue with the best visualization of the junction of the omentum with the peritoneal sac. Again, gentle traction is applied to the omentum while the surgeon spreads, cuts, and sweeps. Throughout this dissection, the surgeon must be vigilant for the appearance of a loop of bowel hidden within these adhesions. Small and large bowel may also be cautiously cut away from the abdominal wall and hernia sac, but less sweeping and traction is applied lest an enterostomy occur. The appearance of bile or succus demands a search for the source, which may be repaired laparoscopically or after conversion to and open laparotomy. Some surgeons regard this complication as a contraindication to the placement of mesh, which is porous and may harbor a chronic infection, requiring eventual removal of the mesh.

After careful inspection of the omentum and other adhesions that have been removed from the abdominal wall, the surgeon makes a visual measurement about the perimeter of the defect to be certain there is an adequately clear zone for attachment of the mesh and its sutures. In general, 4 to 6 cm is sufficient. An important next step is to lower the intra-abdominal CO2 gas pressure to about 6 or 8 mmHg, which minimizes the stretching of the abdominal wall and hernia. If measurements of the defect are made with the abdomen fully inflated at 15 mmHg, the mesh will be too large. It will become very wrinkled and loose when the CO2 is removed at the end of the operation. The size of the defect is measured. Some surgeons use an internal measurement based upon a 2-cm spread, tip to tip, of the opened dissecting instrument. Most perform an external measurement and marking maneuver (Figure 4). A long needle is passed perpendicularly at the edge of the fascial defect in each of the four quadrants. The entrance site at the internal edge of the hernial defect is verified with the videoscope and the external sites are marked with indelible ink. The pattern of the defect is outlined so as to determine the size and shape of the mesh. A 3- to 4-cm margin is drawn out from this defect. This is marked and measured for choosing the mesh's size and shape (Figure 4). The dual-sided mesh is prepared with placement of four sutures, one in each quadrant (Figure 5). The sutures are nonabsorbable 00 in size and may be placed with parallel with or perpendicular to the edge of the mesh. A useful maneuver is to use a pair of parallel sutures in one axis (12 and 6 o'clock) and perpendicular sutures in the other axis (3 and 9 o'clock). In this manner, the axis for internal attachment is identified when the mesh is not round in shape. Each suture is tied in its midpoint and the long tails are left intact. The mesh is rolled snugly with the expanded PTFE surface on the inside and the polypropylene mesh on the outside, so as not to create tension that may peel the two layers apart (Figure 6).

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