Natural History of Hernias
Any ventral hernia can cause significant pain and discomfort. In general, abdominal wall hernias can appear as a lump or bulge in the area of the defect which protrudes intermittently (reducible) or permanently (incarcerated). The content of the hernia may be only fat or, more seriously, bowel can get trapped in the hernia defect. In cases of larger hernia defects, other abdominal organs may also become trapped and/or threatened. If the latter occurs, a bowel obstruction may result and, in severe cases, loss of bowel viability may occur which can cause a severe infection in the body. Part of the bowel itself may die and resection (partial removal) of a portion of the intestine may be necessary. Hernias do not close by themselves nor do they simply “go away.” The natural history of a hernia is that the defect will become larger over time. This can be exacerbated by routine activities that increase the pressure within the abdomen such as lifting, straining, urinating, and defecating. Commonly, hernia defects will also enlarge during pregnancy and should be repaired once child bearing is complete.
Abdominal wall hernias are defects (holes) in a portion of the abdominal wall that result from a congenital or acquired weakness. Congenital hernias generally occur at developmental weak spots of the abdominal wall such as the groin (where the spermatic cord traverses the abdominal wall) or the umbilicus (where the umbilical cord provided nutritional support in utero). The most common type of acquired abdominal wall hernia is what is known as an incisional hernia. An incisional hernia is a hernia that develops through an old surgical incision. The soft tissues within surgical incisions, even when healed optimally, never regain 100% of their original strength. However, if a patient has a condition that prevents the normal healing pathway, then the strength layers of the abdominal wall will not heal completely and a hernia defect can result.
There are certain conditions that are known to contribute to the development of hernias. These include:
- Smoking (and other tobacco use)
- Chronic Constipation or other Excessive Straining
- Inherited Connective Tissue Disorders (such as Ehlers-Danlos Syndrome)
- Heavy Lifting
Pictured below is an example of a ventral incisional hernia through the patient’s previous midline incision. This particular patient was a heavy smoker who underwent emergency abdominal surgery through a midline incision. Although she recovered well from the operation, the deepest layer of connective tissue (known as fascia) did not heal completely. Subsequently, the patient developed an incisional ventral hernia several months after her primary operation.