Hernia is a protrusion and abnormal relocation of an organ in the abdominal cavity through the wall of the cavity that normally contains it. The most common hernias develop in the weak areas in the abdominal wall, such as the inguen (groin), navel, along the middle abdominal line or surgery scars. Symptoms of hernia may vary from small protrusion up to disfiguring, permanent swelling causing discomfort or pain. The most serious risk associated with hernia is incarceration, i.e. lodging of the intestines in the hernial sac. The results may be fatal within just a couple of hours. The incarcerated intestine with strangulated vascular pedicle may cause gangrene, and the infected contents may penetrate the abdominal cavity through the necrotised wall causing peritonitis. The most common is inguinal hernia, which occurs in 10% of men and less commonly in women.

Methods of treatment

The conventional surgical methods consist in stitching the walls of the abdomen, which usually requires placing the stitches under tension. The human body, however, does not tolerate excessively strenuous tissue approximation, therefore the stitches placed under tension often result in tissue distortion causing a new defect. Another complication was pain, resulting from the compression of stitches on nerves. Until recently, a significant failure rate of surgical treatment has been observed. The failure usually included relapse, i.e. recurrence of hernia in the operated area. In some studies, recurrent hernia was observed in up to 20% of patients undergoing conventional surgery. An alternative to "tension" repairs has been long sought, by attempting to fill or strengthen the hernia with a patch. In the 1980s, a method of repairing the hernia using patches was established. Attempts of repairing the hernia by closing the edges under tension were abandoned. Instead, a patch was placed under or over the hernia. Many varieties of this operation were described. Those which have become popular worldwide meet the criteria of tension-free repair methods. The most significant advantages include slight post-operative pain, short recovery period, short absence from work and low recurrence rate. Hernia may also be repaired using laparoscopic methods; however, with regard to inguinal hernia the superiority of laparoscopy over open surgery has not been demonstrated. Analgesia during surgery may include local, lumbar or general anaesthesia. Usually the first two methods are used.