A hernia of the abdominal wall is a protrusion of the abdominal contents through an acquired or congenital area of weakness or defect in the wall. Many hernias are asymptomatic, but some become incarcerated or strangulated, causing pain and requiring immediate surgery. Diagnosis is clinical. Treatment is surgical repair.
(See also Acute Abdominal Pain.)
Abdominal hernias are extremely common. For example, approximately 600,000 ventral hernia repair operations are performed each year in the United States (1).
General reference
1. Schlosser KA, Renshaw SM, Tamer RM, Strassels SA, Poulose BK. Ventral hernia repair: an increasing burden affecting abdominal core health. Hernia. 2023;27(2):415-421. doi:10.1007/s10029-022-02707-6
Classification of Abdominal Hernias
Approximately 75% of all abdominal wall hernias are inguinal (1). Incisional (ventral) and umbilical hernias comprise another 10 to 15%. Femoral and unusual hernias account for the remaining 10 to 15%.
Strangulated hernias are ischemic because of physical constriction of their blood supply. Strangulation can result in bowel infarction, perforation, and peritonitis.
Abdominal wall hernias
Abdominal wall hernias include
Inguinal hernias
Incisional (ventral) hernias
Umbilical hernias
Femoral hernias
Epigastric hernias
Spigelian hernias
Inguinal hernias occur above the inguinal ligament. Indirect inguinal hernias traverse the internal inguinal ring into the inguinal canal, and direct inguinal hernias extend directly forward and do not pass through the inguinal canal. (See also Inguinal hernia in neonates.)
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
Incisional hernias occur through an incision from previous abdominal surgery.
DR P. MARAZZI/SCIENCE PHOTO LIBRARY
Umbilical hernias (protrusions through the umbilical ring) are mostly congenital, but some are acquired in adulthood secondary to obesity, ascites, pregnancy, or chronic peritoneal dialysis.
Femoral hernias occur below the inguinal ligament and go into the femoral canal.
Epigastric hernias occur through the linea alba.
Spigelian hernias occur through defects in the transversus abdominis muscle lateral to the rectus sheath, usually below the level of the umbilicus.
Sports hernias
A sports hernia is not a true hernia because there is no abdominal wall defect through which abdominal contents protrude. Instead, the disorder involves a tear of one or more muscles, tendons, or ligaments in the lower abdomen or groin, particularly where they attach to the pubic bone. It is more appropriately termed athletic pubalgia.
Reference
1. Dabbas N, Adams K, Pearson K, Royle G. Frequency of abdominal wall hernias: is classical teaching out of date?. JRSM Short Rep. 2011;2(1):5. Published 2011 Jan 19. doi:10.1258/shorts.2010.010071
Symptoms and Signs of Abdominal Wall Hernias
Most patients have only a visible bulge, which may cause vague discomfort or be asymptomatic. They can often reduce the hernia by pushing it back through the abdominal wall defect.
A strangulated hernia causes steady, gradually increasing pain, typically with nausea and vomiting. The hernia itself is tender, and the overlying skin may be erythematous; peritonitis may develop depending on location, with diffuse tenderness, guarding, and rebound.
Diagnosis of Abdominal Wall Hernias
Clinical evaluation
The diagnosis of an abdominal hernia is clinical. Because the hernia may be apparent only when abdominal pressure is increased, the patient should be examined in a standing position. If no hernia is palpable, the patient should cough or perform a Valsalva maneuver as the examiner palpates the abdominal wall. Examination is focused on the umbilicus, the inguinal area (with a finger in the inguinal canal in males), the femoral triangle, and any incisions that are present.
Most hernias, even large ones, can be manually reduced with persistent gentle pressure; placing the patient in the Trendelenburg position may help. An incarcerated hernia cannot be reduced and can be the cause of a bowel obstruction.
Inguinal masses that resemble hernias may be the result of adenopathy (infectious or malignant), an ectopic testis, or lipoma. These masses are solid and are not reducible. A scrotal mass may be a varicocele, hydrocele, or testicular tumor.
Ultrasound may be done if physical examination is equivocal.
Treatment of Abdominal Wall Hernias
Surgical repair
Groin hernias typically should be repaired electively because of the risk of strangulation, which results in higher morbidity (and possible mortality in older patients).
Asymptomatic inguinal hernias in men can be observed; if symptoms develop, they can be repaired electively. Repair may be through a standard incision or a laparoscope
An incarcerated or strangulated hernia of any kind requires urgent surgical repair.
Prognosis for Abdominal Wall Hernias
Congenital umbilical hernias rarely strangulate and are not treated; most resolve spontaneously within several years. Very large defects may be repaired electively after age 2 years.
Umbilical hernias in adults cause cosmetic concerns and can be electively repaired; strangulation and incarceration are unusual but can happen and usually contain omentum rather than intestine.
