Classification
There are two types of inguinal hernia, direct and indirect, which are defined by their relationship to the inferior epigastric vessels. Direct inguinal hernias occur medial to the inferior epigastric vessels when abdominal contents herniate through a weak spot in the fascia of the posterior wall of the inguinal canal, which is formed by the transversalis fascia. Indirect inguinal hernias occur when abdominal contents protrude through the deep inguinal ring, lateral to the inferior epigastric vessels; this may be caused by failure of embryonic closure of the processus vaginalis.
In the case of the female, the opening of the superficial inguinal ring is smaller than that of the male. As a result, the possibility for hernias through the inguinal canal in males is much greater because they have a larger opening and therefore a much weaker wall through which the intestines may protrude.
| Type | Description | Relationship to inferior epigastric vessels | Covered by internal spermatic fascia? | Usual onset |
| indirect inguinal hernia | protrudes through the inguinal ring and is ultimately the result of the failure of embryonic closure of the internal inguinal ring after the testicle passes through it | Lateral | Yes | Congenital |
| direct inguinal hernia | enters through a weak point in the fascia of the abdominal wall (Hesselbach triangle) | Medial | No | Adult |
Inguinal hernias, in turn, belong to groin hernias, which also includes femoral hernias. A femoral hernia is not via the inguinal canal, but via the femoral canal, which normally allows passage of the common femoral artery and vein from the pelvis to the leg.
In Amyand's hernia, the content of the hernial sac is the vermiform appendix.
In Littre's hernia, the content of the hernial sac contains a Meckel's Diverticulum.
Clinical classification of hernia is also important according to which hernia is classified into
Reducible hernia: is one which can be pushed back into the abdomen by putting manual pressure to it.
Irreducible hernia: is one which cannot be pushed back into the abdomen by applying manual pressure.
Irreducible hernias are further classified into
Obstructed hernia-is one in which the lumen of the herniated part of intestine is obstructed but the blood supply to the hernial sac is intact.
Incarcerated hernia-is one in which adhesions develop between the wall of hernial sac and the wall of intestine.
Strangulated hernia- is one in which the blood supply of the sac is cut off, thus, leading to ischemia. the lumen of the intestine may be patent or not.
Read more about this topic: Inguinal Hernia