What is an inguinal hernia?
Inguinal hernias are those which are seen in the groin region and account for about 75% of all hernias. With an inguinal hernia, the contents of the abdominal cavity protrude through the inguinal canal. It is more prevalent in men. Inguinal hernias are either of a direct type or indirect type but the distinction is not critical as both are managed with similar surgical procedures.
Read more about the part, types, causes and risk factors of a hernia under What is a Hernia.
Indirect Inguinal Hernia
The indirect inguinal hernia is the most common of all type of inguinal hernias. Indirect inguinal hernias are more common in males and more frequently seen on the right side. It is common in children and young adults and may be due to congenital causes. The hernial sac is believed to be the remains of an outpouching of part of peritoneum in fetal life (the processus vaginalis) that is responsible for the formation of inguinal canal.
The hernial sac of an indirect inguinal hernia passes from the deep (internal) inguinal ring towards the external (superficial) inguinal ring through the inguinal canal. The sac then extends into the scrotum in men or labia major in women. The neck of the hernial sac in indirect inguinal hernia will be at the deep inguinal ring, at the outer (lateral) side of the inferior epigastric blood vessels. The body of the hernial sac will be in the inguinal canal, extending into the scrotum or labia. Excluding a few large direct hernias, most hernias reaching scrotum are indirect inguinal hernias.
Picture from Wikimedia Commons
Direct Inguinal Hernia
Direct inguinal hernia accounts for about 25% of inguinal hernias. Direct hernias are rare in women. The hernial sac of a direct inguinal hernia passes directly through the wall of inguinal canal along the inner (medial) side of the deep inguinal ring and inferior epigastric vessels. The direct inguinal hernia usually appears like a generalized bulge and the hernial sac has a wide neck. Most direct inguinal hernias are seen in old men with weak abdominal muscles and are often found on both sides.
A co-existing direct and indirect inguinal hernia is called a pantaloon-type hernia. They two hernias bulge through the either sides of the inferior epigastric blood vessels appearing like a pantaloon.
Sliding Inguinal Hernia
A sliding hernia is one in which a portion of the wall of the hernia comprises of an internal organ. Sliding inguinal hernias commonly involve the colon or urinary bladder. Most sliding inguinal hernias are indirect inguinal hernias, but occasionally direct sliding hernias can also develop. Failure to identify the visceral part of the sliding hernia correctly can result in the injury of the bladder or bowel during surgery.