Femoral hernias

What are femoral hernias?

Hernias in the groin are either inguinal or, less commonly, femoral in origin.

Inguinal hernia

The femoral canal has the inguinal ligament as its anterior border, the pectineal ligament as its posterior border, the lacunar ligament as its medial border, and the femoral vein as its lateral border.

Epidemiology¹

Femoral hernias account for only around 3% of all groin hernias. The lifetime incidence of a groin hernia is 27% to 43% in men and 3% to 6% in women.

Femoral hernias are more common in women than in men, though inguinal hernias remain the most common groin hernias in women.

The prevalence of femoral hernias increases with age, as does the risk of complications.

10% of women with a femoral hernia and 50% of men with a femoral hernia will have a co-existing inguinal hernia.

Femoral hernia symptoms (presentation)

• Presentation is as a lump in the groin, lateral and inferior to the pubic tubercle. A large hernia may bulge over the inguinal ligament.

• The femoral hernia often bulges more on coughing or straining, and reduces in size or disappears when relaxed or supine.

• Femoral hernias are more common on the right (due to a developmental delay in closure of the processus vaginalis).

• There may be a cough impulse.

• Femoral hernias are more likely to strangulate than inguinal hernias.

Investigation

• Diagnosis is largely clinical but ultrasound confirmation is often required before making a referral.

• Imaging techniques are helpful. Ultrasound scanning is most commonly used but CT scans can be helpful in patients with incarceration or strangulation.¹

Differential diagnosis

Other causes of lumps in the groin include:

• Inguinal hernia.

• Hydrocele (when differentiating from an inguinoscrotal hernia, note that it is possible to get above a hydrocele on examination).

• Spermatic cord hydrocele.

• Enlarged lymph node.

• Psoas abscess or bursa.

• Saphena varix.

• Varicocele.

• Haematoma.

Femoral hernia complications

Femoral hernias are at a 12 times higher risk of strangulation than inguinal hernias.

The risk of strangulation in a femoral hernia is 22% at 3 months and 45% at 21 months.

Femoral hernias may not be noticed by the patient prior to strangulation, especially in those who have obesity.

One study reported that 45.9% of patients required femoral hernia repair as an emergency.²

If strangulation occurs, the lump may become red and tender as well as tense and irreducible. Other features include colicky abdominal pain, distension and vomiting, indicating bowel obstruction.

Femoral hernia treatment and management³

In view of the higher risk of strangulation, it is recommended that femoral hernias should be repaired; referral should be made for elective repair as soon as the diagnosis is made.⁴ In many parts of the UK, there is a hernia pathway which includes all femoral hernias (confirmed by ultrasound scan) but only includes other hernias that are symptomatic.

Femoral hernias may be repaired using a standard inguinal approach, an open preperitoneal approach, or a minimally invasive (laparoscopic or robotic-assisted laparoscopic) approach.¹⁵Laparoscopy does not appear to lead to more complications,⁶⁷ but there is no consensus on the best approach, particularly as these often present in an acute situation and are therefore dealt with by junior surgeons.⁸

Emergency femoral hernia repair (for a strangulated hernia) is associated with a significantly higher risk of complications, including bowel resection, and a higher mortality than elective repairs.²

Prognosis

The mortality for elective hernia repair is low, regardless of age. However, after emergency surgery, mortality is increased seven-fold.⁹

Studies report that the overall operative mortality rate for strangulated hernias ranges from 1.4-13.4% but there is limited recent data.

Recurrence rates for femoral hernias are between 1 and 10%. They are more common in smokers and people with obesity, increased intra-abdominal pressure, coexisting infection, collagen tissue disorders, diabetes, and poor nutritional state.¹

Chronic pain has been reported in up to 15% of people after femoral hernia repair.¹