1300 HERNIA (1300 437 642)
Why do they occur?
Basically the abdominal wall has been modified at particular sites to developmental requirements. Hernias almost exclusively occur at these well recognised sites of weakness.
All hernias occur at the site of a structural weakness in the abdominal wall - that is where the 3-layer muscle structure of the abdominal wall has been modified developmentally and anatomically. In the case of the umbilical region and epigastrium where the muscle and fascia have fused into one layer, in the midline of the abdomen wall. As shown in A & B - representing midline hernias such as an epigastric hernia or umbilical hernia.
The commonest site for hernias is the groin. In the groin there are 2 types of hernias - inguinal and femoral. The femoral is lower and relatively rare. It occurs relatively more frequently in females.
The INGUINAL hernia, which is by far the most common, occurs at any age. The descent of the testes and its cord through the muscle wall of the groin into the scrotum at birth has left a potential weakness, through which the hernia descends. Any activity which then constantly or suddenly increases intra abdominal pressure or weakens the muscle may cause a hernia eg, cough, constipation, bladder obstruction or heavy lifting. Ageing weakens the muscles. Obesity increases both the intra abdominal pressure and reduces the muscle strength.
There are 2 types of inguinal hernias
Generally the indirect hernia is more dangerous, it is protruding through a narrow neck of muscle, which can trap the contents as opposed to, a direct hernia in which is just an enlarging bulge.
This is the reason why direct hernias can be left longer without surgery.
However, it is not always clinically possible to distinguish between direct and indirect hernias.
The thin inner lining of the abdominal wall (the peritoneum) protrudes through a defect or weakens in the muscle and expands like a balloon. The abdominal contents move in and out of the sac.
TYPES OF HERNIAS
- in the groin
Hernias are described as:
a) REDUCIBLE: That is those that are not present all of the time and often disappear temporarily when you lie down or can be manipulated back into the abdomen.
b) IRREDUCIBLE HERNIA
The bowel can be blocked causing abdominal
pain and vomiting.
The contents may be nipped off suddenly at the narrow neck of the sac.