2 Clinical need and practice

2.1 An inguinal hernia is a protrusion of a sac of peritoneum (often containing intestine or other abdominal contents) through a weakness in the abdominal wall in the groin. It usually presents as a lump, with or without some discomfort that may limit daily activities and the ability to work. Around 98% of inguinal hernias are found in men because of the vulnerability of the male anatomy to the formation of hernias in this region. Inguinal hernias can occasionally be life-threatening if the bowel within the peritoneal sac strangulates and/or becomes obstructed.

2.2 In England, there were approximately 70,000 surgical repairs of inguinal hernia in 2001/02, affecting 0.14% of the population and utilising over 100,000 NHS bed-days of hospital resources. Of these procedures, 62,969 were for the repair of primary hernias and 4939 for the repair of recurrent hernias.

2.3 Surgical repair (herniorraphy) is undertaken in most individuals presenting with inguinal hernia in order to close the defect, alleviate symptoms of discomfort, prevent serious complications (that is, obstruction or strangulation of the bowel) and reduce the risk of recurrence.

2.4 Most hernia repairs are undertaken as elective procedures. However, 4.8% of primary repairs and 8.6% of recurrent hernias present as an emergency with a complication. Some individuals present with bilateral hernias, which may be repaired during the same operation or at a later date, and up to 30% of people with a primary unilateral hernia subsequently develop a hernia on the opposite side.

2.5 Traditional methods of open repair (for example, the Bassini method), which repair the hernia defect by suturing, have not changed significantly since their introduction in the late 19th century. Recently, the availability of prosthetic meshes has led to an increase in the number of 'tension-free' methods of reinforcing the inguinal region. Open mesh methods of repair are classified as open flat mesh (OFM; for example, the Lichtenstein method), open preperitoneal mesh (OPPM; for example, the Stoppa and Nyhus methods) and open plug and mesh repair (OPM; for example, the Rutkow method). Open methods of hernia repair are associated with postoperative pain and numbness because of the large inguinal incision. OFM repairs are thought to be the principal surgical method of hernia repair in the UK.