About Parastomal Hernia
A parastomal hernia means a hernia that occurs adjacent to or around an existing stoma. The latter is in the form of either a colostomy or an ileostomy both of which are formed for numerous reasons. In the process of forming a stoma a defect is made in the muscle of the abdominal wall allowing the bowel to be brought through to the surface. Normally this defect is just large enough to accommodate the stoma itself but with time and with some wear and tear the defect can widen. This then allows another loop of bowel from the abdominal cavity to protrude through the defect in the muscle of the abdominal wall but obviously not through the skin.
The typical symptoms of a parastomal hernia are swelling and discomfort around the region of the stoma. The swelling makes it difficult for the stoma appliance to sit snuggly around the stoma itself. Occasionally it can produce sufficient pressure on the stoma such that the latter is prevented from functioning normally. Very occasionally as with other types of hernia the contents of the hernia sac in particular a loop of bowel can become irreducible and strangulate.
The decision to repair a parastomal hernia is very much related to the degree of inconvenience and the symptoms that are caused. Small parastomal hernias are often managed conservatively. That said most parastomal hernias will increase in size over time and a strong case can be made for repairing a parastomal hernia whilst it is relatively small.
The options with regard to the repair of a parastomal hernia rests between repairing the defect with a piece of plastic mesh which can be placed on the outside of the muscle layer or the inside (using a laparoscopic technique). But the technical challenge is to close off the defect sufficient to prevent any further herniation of abdominal content but not to constrict the stoma in any way. Parastomal herniae can be quite large and under these circumstances the alternative is to resite the stoma usually on the other side of the abdomen. This in itself is a major undertaking and usually involves opening up the abdomen (a laparotomy). The operation is therefore usually as big as the operation that necessitated the stoma in the first place. Having resited the stoma it is then a relatively straight forward process of closing the original stoma and hernia defect, once again usually using mesh.
The main problem with parastomal hernia repairs, particularly if you’re using mesh, is avoiding the risk of infection. The operation site is by definition site contaminated with bacteria as a result of the bowel being intimately related with the hernia. If bacteria are introduced into a foreign body such as mesh it then becomes extremely difficult to eliminate them. The incidence of infection post operatively as a consequence with parastomal hernias is relatively high. And this in itself can result in a further recurrence and it may necessitate the removal of the mesh and patients are as a consequence back to square one.