Abdominal incisional hernias are common after operations requiring a large incision. These can be at the umbilicus, above the umbilicus (epigastric) or along the full length of the incision (massive ventral hernia) (figure 1).
In severe cases, portions of organs may move through the hole in the muscle.
How do they form?
During surgery an incision is made in the muscles that make up the abdomen. For some reason, that muscle doesn't heal, so a gap opens up as the muscles tighten and release during activities. Instead of a flat, strong piece of muscle, you have a piece of muscle that has a small gap in it. After a while, the tissues underneath realize there is an escape route through the muscle, and they start to poke through the opening, where they can be felt under the skin.
Who is at risk for an incisional hernia?
Incisional hernias are more common in obese and pregnant patients. Previous multiple abdominal surgeries may increase the risk of an incisional hernia.
Significant weight after an abdominal surgery is a risk factor as is, pregnancy or participation in activities that increase abdominal pressure like heavy lifting.
The incision is weakest, and most prone to a hernia, during the first 6-12 weeks after surgery while it is still healing. While incisional hernias can develop or enlarge months or years after surgery, they are most likely to occur in the first 6-12 weeks following surgery.
Diagnosing an incisional hernia
Incisional hernias may seem to appear and disappear, which is referred to as a "reducible" hernia.
The hernia may not be noticeable unless the patient is involved in an activity that increases abdominal pressure, such as coughing, sneezing, pushing to have a bowel movement, or lifting a heavy object.
CT scan or ultrasound is sometimes necessary to determine the extent of the hernia as well as its contents. Sometimes these imaging modalities also determine synchronous hernias nearby.
Incisional hernia treatment
An incisional hernia may not be symptomatic and small enough that surgical repair is an option. If the hernia is large, causes pain or is steadily growing, surgery may be recommended. Another option is a truss, a garment that is similar to a weight belt or girdle, that applies constant pressure to the hernia.
When is incisional hernia surgery necessary?
An Incisional hernia may require surgery if it is painful, enlarges over time, is cosmetically unappealing, or irreducible. In many cases surgery can be performed laparoscopically with small key-hole incisions.