About Ventral or Incisional Hernia
A ventral hernia is the name given to a hernia associated with the anterior abdominal wall, so strictly speaking this should include umbilical and some of the more unusual herniae such as a spigelian hernia. However it is generally synonymous with incisional hernia, which is a weakness of the muscles of the anterior abdominal wall arising from a previous incision. The incision may have been carried out for a variety of reasons in order to gain access to the abdominal cavity. It is usually off the midline and transverse. Equally it can be low down towards the bikini line as in a pfannenstiel incision which is done for operations such as caesarean section and hysterectomy. The hernia may extend for the whole length of the original incision or sometimes just part of it.
The muscle of the abdominal wall is inherently weakened when it is incised but is usually closed comprehensively at the time of surgery. A significant pre-disposing factor to the development of weakness of the muscle and thus a hernia, is infection in the wound just after surgery. This is more likely to occur with certain types of operations such as bowel operations but nevertheless it should only be in the region of 2-3% of cases. The hernia develops over time – generally over a period of several months post operatively.
The symptoms very much depend upon the site and size of the hernia but the usual symptoms are discomfort and swelling, once again exacerbated by exertion and released upon reclining. Due to adhesions the contents of the incisional hernia tend to be incarcerated (irreducible). As with any other type of hernia there is always a risk of strangulation. This is where a segment of bowel becomes stuck in the hernia and cuts off its own blood supply. This is very much related to the size of the neck of the hernia with a small neck being much more predisposed to strangulation.
Incisional hernias are repaired usually because they are unsightly but also because of discomfort. The approach is either by an open technique (through the original incision) or using the laparoscopic approach (keyhole surgery). The choice very much depends on the size of the hernia, with small hernias lending themselves to relatively straight forward repair laparoscopically. Mesh is almost always used routinely to reinforce the repair. This is usually polypropylene which is totally inert and stays in place forever.