A hernia is a defect in the abdominal wall allowing intra-abdominal contents to protrude outside the abdominal cavity. Most abdominal wall hernias occur at the groin and umbilicus. Incarceration is defined as the inability to reduce the protruding tissue to its normal position. Strangulation occurs when the blood supply of the hernia’s contents is obstructed and tissue necrosis ensues. An incisional hernia may manifest clinically as a mass or palpable defect adjacent to a surgical incision and can be reproduced by having the patient perform the Valsalva maneuver. Peristomal hernias are a type of incisional hernia where the abdominal wall opening is too large, allowing intra-abdominal contents to accumulate outside the abdominal cavity. Obesity and wound infection, which interfere with wound healing, predispose to the formation of incisional hernias. The defect of an indirect inguinal hernia is the internal (abdominal) inguinal ring and may be manifest in either sex by a bulge over the midpoint of the inguinal ligament that increases in size with Valsalva maneuver. A fingertip placed into the external ring through the inguinal canal may palpate the defect. A direct hernia may be manifested by a bulge midway adjacent to the pubic tubercle and may be felt by the pad of the finger placed in the inguinal canal. The defect is in the posterior wall of the inguinal canal. Direct inguinal hernias are usually painless and occur in males. Femoral canal hernias are more common in women and are prone to both strangulation and incarceration.
Hernia Types. Drawings of the different hernia types using the landmarks of the inguinal ligament and pubic tubercle.
Incisional Hernia. An asymptomatic incisional hernia in an obese male that developed after coronary artery bypass graft. The CT in Fig. 7.52B demonstrates a loop of bowel protruding through the abdominal wall defect. (Photo contributor: Lawrence B. Stack, MD.)
Incisional Hernia CT Scan.
Indirect Inguinal Hernia. A left indirect inguinal hernia in a female patient. (Photo contributor: Lawrence B. Stack, MD.)
Direct Inguinal Hernia. A direct inguinal hernia. Note the bulge adjacent to the left pubic tubercle. (Photo contributor: Lawrence B. Stack, MD.)
Nausea and vomiting may be present if incarceration with bowel obstruction occurs. Strangulation can lead to fever, peritonitis, and sepsis.
Peristomal Hernia with Abscess. Peristomal pain, induration, and fever prompted a CT, which reveals a peristomal hernia and cutaneous abscess. (Photo contributor: ...