A hernia is a weakness or hole in the abdominal muscle wall through which abdominal contents protrude causing a bulge. The protruding contents push out a pouch of the abdominal lining or peritoneum through the weakness forming the “sac of the hernia”.
Why do they occur?
There are sites of potential weakness in the abdominal wall. The areas in which hernias most commonly develop are the umbilicus, the groin and where there has been an abdominal incision.
There is frequently an opening in the muscle layer at the umbilicus that may have been present since birth. It may enlarge due to anything that causes raised abdominal pressure, such as muscular strain or pregnancy. A hernia may then appear.
In male patients, blood vessels running through the groin muscles to the testicle create a weak area where an indirect inguinal hernia may develop. Strain or muscle deterioration can enlarge this weak spot and force through it, abdominal contents resulting in the development of a hernia. Inguinal hernias may occur in women, although less commonly, and follow the round ligament of the uterus.
Other causes include incisions from old operations which may weaken the abdominal wall, if they do not heal properly after surgery or are weakened by infection. Muscle wall deterioration with age, inactivity or strain which may allow the muscle wall to tear or bulge, resulting in the development of various forms of hernias.
Why should it be repaired?
Why choose laparoscopic repair?
I believe that laparoscopic repair is less painful than conventional repair, both in the short and long term. It allows for shorter hospitalisation and the patients are able to resume normal activities at an earlier stage, than with traditional repairs. Dr Ritchie has only seen one recurrence in an inguinal laparoscopic repair in over 3500 cases, whereas traditional methods carry a 5% recurrence rate. The only disadvantages are that the procedure requires a general anaesthetic and that there are more equipment expenses namely; the laparoscopic ports, the mesh and the hernia tacker, that is used to fix the mesh in place. As mentioned however, hospital stays and convalescent times tend to be shorter than with open repairs.
How is it performed?
This description refers to extra-peritoneal laparoscopic repair for an inguinal or femoral hernia. Under a general anaesthetic, three small incisions are made in the abdominal wall. The largest of these is a vertical incision about 2cm just below the umbilicus. A small transverse incision in the superficial sheath of the rectus abdominis muscle, the only cutting of muscle in this procedure, is made and a balloon dilating device is passed downwards to the pubic bone between the abdominal muscles and the lining of the abdomen, the peritoneum. The balloon is blown up separating the peritoneum from the muscle layer. This separates easily with little bleeding. The balloon is withdrawn after deflation and replaced by a tube-like structure called a laparoscopic port. The space is inflated with CO2 and a telescope inserted into the space. The abdominal cavity is not entered during this procedure, therefore greatly reducing the likelihood of damage to the abdominal organs or production of adhesions. Two further 0.5 cm incisions are made between umbilicus and pubic bone on the opposite side of the abdominal wall to the hernia to puncture into the space two fine 0.5 cm diameter ports to accommodate operating instruments. The peritoneum is then gently pushed away from the muscle layer until a sizeable space is created and the muscle defect is revealed. The sac of the hernia is pulled back into this space. Other structures that are revealed include the back of the pubic bone and the blood vessels running to the leg and, in a male patient, those running to the testicle and the abdominal wall. Once the muscle layer is cleared a piece of flexible polypropylene mesh measuring 12 X 15cm approximately, is then slid down the large port and manoeuvred so as to cover the hole in the muscle and also all other potential areas where hernias can occur in this area. The mesh is held in place with approximately 8-10 tiny absorbable tacking devices. The space is filled with local anaesthetic and the ports withdrawn.
The positive pressure in the abdominal cavity pushes the peritoneum onto the mesh trapping it like the meat in a sandwich. Any increase in the abdominal pressure, as in straining, simply pushes the mesh firmly against the abdominal wall. Straining therefore, does not have the effect of pulling apart the repair as it does in sutured repairs. This contributes enormously to the strength and durability of the repair. As the repair is tension free, it is less painful than sutured techniques. Skin wounds are closed with dissolving sutures.