An umbilical hernia is usually a congenital defect, although a variation may follow surgery such as the placement of an incision or laparoscopic port in this region. The increased susceptibility to strangulation of an umbilical hernia in an adult necessitates repair as the patient's condition permits.
Repair of an umbilical hernia in the very young child is rarely indicated, since 80 percent of these fascial defects will close by the age of 2 years. In addition, the incidence of incarceration and strangulation within an umbilical hernia in this age group is extremely low. However, if supportive measures such as the “keystone” type of strapping during infancy have failed and the fascial ring is sufficiently large to admit the index finger, the hernia should be repaired before school age.
This defect is usually seen in either children or obese adults, and the preoperative preparation depends entirely upon the patient's general condition and age. Obese patients are placed on a reducing diet. A general medical assessment is indicated. The patient may be placed on a low-residue diet for a day or two and the bowels emptied with a mild purgative. Repair is delayed in the presence of acute respiratory infection, chronic cough, or infection about the navel. Special attention is given to cleaning of the navel.
Spinal anesthesia may be preferred in large hernias because of the excellent relaxation it provides; however, inhalation anesthesia can be used if not contraindicated. Inhalation anesthesia is the method of choice for children.
The patient is placed in a comfortable supine position.
The skin is prepared in the usual manner after the umbilicus has been carefully cleaned. This may require cotton applicators saturated with antiseptic to reach any deep crevices.
A curved incision placed superiorly or inferiorly about the umbilicus is most commonly used (Figure 1). A vertical incision that curves around the umbilicus may be necessary for very large hernias. The umbilicus proper should be retained in the skin flap. The incision is made to the hernia sac. The sac is easily mobilized except for its attachment to the back of the umbilical skin. This is dissected carefully so as not to create a buttonhole that may put the repair at risk for infection. The neck of the herniated sac is then dissected from adjacent tissues by a combination of blunt and sharp dissection, which is carried down to the level of the linea alba and anterior sheaths of the rectus muscle.
Most commonly, omentum is contained within the sac, but small and large bowel may also be present. Frequently the omentum will have formed adhesions to various areas of the sac, thus preventing reduction of the hernia. Sharp dissection is required to detach hernial contents from the sac as well as from the peritoneum around the neck of the sac as it joins the peritoneum. When there is a strong suspicion of gangrenous intestine within the sac, the abdominal cavity should be entered through an extended midline incision that enters either above or below the umbilicus. This incision is extended to the fascial defect and up the side of the sac so as to allow complete mobilization of the incarcerated bowel. The intestine is either reduced or resected as indicated. In the majority of cases, omentum is incarcerated within the sac.
In these patients, the sac may be opened (Figure 2). If the omentum cannot easily be freed and/or reduced, it is wise to resect it with sequential clamping and suture ligature placement. When the contents of the sac have been reduced and its neck has been well defined, a decision is made as to how to repair the fascial defect.
In general, when the defect is less than 2 cm in diameter, the peritoneum is closed and the excess sac excised. The perimeter of the fascial defect is cleaned of fat both anteriorly and posteriorly, and a primary repair is performed using interrupted 00 sutures that may be of a delayed absorbable or nonabsorbable nature (Figure 3). This primary repair is performed only for small defects of 2.5 cm or less.
If an intermediate-sized defect in the range of 2 to 4 cm is found, many surgeons prefer to repair it with the two layer “vest-over-trousers” (Mayo) technique (Figures 4, 5, and 6). The upper fascia is imbricated over the lower fascia with a row of interrupted 00 sutures. These begin and end high on the vest, while the trousers are secured in a horizontal manner at the belt line (Figure 4). When these sutures are secured, the free superior edge (vest) overhangs the inferior fascia (trousers) and a second layer of interrupted 00 sutures is used to secure the free edge (Figure 5A). The technique is illustrated schematically in the cross-sectional view illustrated in Figure 6.
Many surgeons believe that a medium to large defect should be repaired with mesh, as primary tissue repairs in large hernias have a significant recurrence rate. The preferred site for placement of the mesh is posterior to the defect and posterior rectus sheath. If the zone between the peritoneum and posterior rectus sheath can be freely dissected, some surgeons use a polypropylene mesh after first being certain that the omentum is directly behind this region when the umbilical hernia sac is closed. Alternatively, if this plane cannot be developed and the mesh must be placed in an intraperitoneal position, a dual-sided mesh is used wherein the smooth, nonadherent expanded polytetrafluoroethylene (PTFE) surface is posterior toward the omentum and bowel, while the polypropylene screen-like mesh is anterior against the peritoneum and posterior fascia (Figure 6A). The mesh should be sized to extend 3 to 5 cm beyond the anticipated edges of the closed defect. This mesh is secured with nonabsorbable 00 mattress sutures that are placed full-thickness through the linea alba at the 12 and 6 o'clock positions and through the rectus sheaths and muscle at the 3 and 9 o'clock positions. These sutures should secure only the polypropylene mesh and should not go full-thickness through the PTFE, as this may present a free intra-abdominal loop that may catch a loop of bowel. The anchoring sutures are tied and the defect is closed either vertically or transversely using interrupted 00 sutures.
After careful hemostasis is obtained, the apex of the subcutaneous tissue beneath the umbilicus is sutured down to the linea alba with 00 absorbable sutures. This produces the desirable ingoing bellybutton. Further absorbable sutures are used to obliterate the subcutaneous dead space. A triple-bite suture that secures Scarpa's fascia to the deep fascia and then the Scarpa's fascia on the other side of the incision minimizes the space for a potential accumulation of serum or a hematoma. When the hernia is quite large, a closed-system Silastic suction catheter may be placed through an adjacent stab wound.
Special attention is given to the avoidance of abdominal distention. An adhesive tape strip 3 in. wide is liberally applied across the abdomen, and the patient may use an abdominal binder for approximately 1 month. The patient is warned to avoid overly heavy lifting and straining.
A curved incision around the superior half of the umbilical depression is made and the hernia sac is freed down to the linea alba. This dissection extends laterally onto either rectus sheath. The hernia sac is dissected free from the back of the umbilical skin, using countertraction with skin hooks. The fascia is cleaned for a few centimeters in all directions. In most patients, the sac can be reduced without being opened. The edges of the fascial ring are grasped with Kocher clamps and the posterior aspect of the fascia is cleaned for 1 or 2 cm. As most of these fascial defects are small, a primary repair using 00 interrupted sutures can be performed in either a vertical or horizontal manner, depending upon the shape of the defect.
The skin margins are approximated with interrupted subcuticular 00000 absorbable suture. Skin strips are applied and the umbilicus is packed with a small wad of gauze. A dry sterile dressing is applied.
The routine postoperative care is performed. Most patients are able to tolerate fluid within a few hours and are discharged home within a day on a soft diet. The skin of the umbilicus should be observed for viability if an extensive dissection has been performed. In most patients, the curved periumbilical incision becomes minimally visible as the area heals.