Inguinal Hernia

An inguinal hernia, also known as a groin hernia, is a medical condition where contents of the abdominal cavity protrude through the inguinal canal. This condition primarily affects males due to the anatomical differences in the inguinal canal but can also occur in females.

Signs and Symptoms

Inguinal hernias usually present as bulges in the groin area, which become more prominent when coughing, straining, or standing up and typically disappear when lying down. Mild discomfort can develop over time.

Frontal view of an inguinal hernia (right).

As the hernia progresses, abdominal contents such as the intestines can descend into the hernia, risking intestinal obstruction. Significant pain at the hernia site suggests complications like incarceration (the hernia cannot be reduced back into the abdomen) or strangulation (the hernia becomes deprived of blood supply), which can result in gut ischaemia and potentially fatal consequences.

Another frontal view of such a hernia, this time without pubic hair.

Pathophysiology

In males, indirect hernias follow the route of the descending testes from the abdomen into the scrotum during development. The larger size of the inguinal canal might be one reason why men are 25 times more likely to have an inguinal hernia than women. Inguinal hernias mostly contain the omentum or part of the small intestines. Occasionally, uncommon contents like the appendix, urinary bladder, or ovaries may be involved.

Illustration of an inguinal hernia.

Diagnosis

Diagnosis is primarily based on medical history and physical examination. When necessary, medical imaging such as ultrasonography, CT, or MRI can be used to confirm the diagnosis or rule out other conditions.

An incarcerated inguinal hernia as seen on cross-sectional CT scan.

Two types of inguinal hernia exist: direct and indirect. Direct inguinal hernias occur through a weak spot in the fascia of the posterior wall of the inguinal canal and are medial to the inferior epigastric vessels. Indirect inguinal hernias protrude through the deep inguinal ring and are lateral to the inferior epigastric vessels.

Direct Inguinal Hernia

Direct inguinal hernias are more common in middle-aged and elderly men. They protrude through a weakened area in the transversalis fascia near the medial inguinal fossa within Hesselbach's triangle.

Indirect Inguinal Hernia

Indirect inguinal hernias occur due to the failure of embryonic closure of the deep inguinal ring and can happen at any age. They are the most common type of groin hernia in both males and females.

Ultrasound image of inguinal hernia. Moving intestines in inguinal canal with respiration.

Management

Conservative

Conservative management includes the use of a hernia truss to contain a reducible inguinal hernia within the abdomen. However, this method is controversial due to a lack of evidence on its effectiveness and potential complications such as hernia strangulation.

Surgical

Surgical correction, or hernia repair, is recommended for symptomatic hernias. Surgery can be performed openly or laparoscopically, with mesh often being used to reduce the recurrence rate.

Surgical incision in the groin after inguinal hernia operation.

For children, surgery is always recommended. Emergency surgery is required for incarcerated or strangulated hernias.

Frank Lamb, affected by a major inguinal hernia since the age of 9, underwent successful surgery in 1867.

Epidemiology

Inguinal hernias are significantly more common in men, with an incidence eight times higher than in women. Direct inguinal hernias are less common, accounting for about 25-30% of cases, primarily affecting men over 40 years of age.

Self-assessment MCQs (single best answer)

What primarily causes the bulge seen in an inguinal hernia?

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Which anatomical structure is larger in males and contributes to a higher incidence of inguinal hernias?

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What complication involves the hernia becoming deprived of blood supply, potentially leading to gut ischaemia?

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Which type of inguinal hernia occurs through a weak spot in the fascia of the posterior wall of the inguinal canal?

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Which diagnostic method is primarily used for diagnosing an inguinal hernia?

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What type of medical imaging can be used to confirm the diagnosis of an inguinal hernia?

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Direct inguinal hernias are more common in which population group?

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What is the primary content found in most inguinal hernias?

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Which surgical approach is NOT commonly used for hernia repair?

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What is the recommended treatment for children with inguinal hernias?

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