• Clinical science

Femoral hernia

Abstract

A femoral hernia is an uncommon type of inguinal hernia, in which intra-abdominal contents (e.g., intraperitoneal fat, mesentery, bowels) herniate into the femoral canal through the femoral ring. Risk factors for femoral hernias include old age, female gender, obesity, and previous hernia repair. Patients present with a globular swelling inferior to the inguinal ligament and medial to the femoral vein that worsens with coughing or straining. The diagnosis is primarily clinical with ultrasonography being indicated if the diagnosis is inconclusive. Although femoral hernias are uncommon, they are associated with a high risk of incarceration and strangulation and should, therefore, be surgically treated as early as possible. The preferred treatment for non-complicated femoral hernias is mesh hernioplasty, while repair without a mesh is used for complicated femoral hernias.

Epidemiology

  • Uncommon hernia (∼ 5% of all hernias)[1]
  • Sex: > (3:1)
  • Peak incidence: 40–70 years[2]

Epidemiological data refers to the US, unless otherwise specified.

Etiology

  • Advancing age and female gender (see “Epidemiology” above)
  • Increased intra-abdominal pressure
  • Multiparity
  • Sudden weight loss
  • Previous abdominal surgeries (especially those involving the inguinal region)

In contrast to indirect inguinal hernias, which may occur congenitally, femoral hernias are almost always acquired.


References:[3]

Pathophysiology

  • Boundaries of the femoral canal
    • Anterior: inguinal ligament (Poupart's ligament)
    • Posterior: pubic ramus and pectineal ligament
    • Medial: lacunar ligament (Gimbernat ligament)
    • Lateral: femoral vein
  • Typical femoral hernia: (common): protrusion of intraperitoneal contents along with the transverse abdominal fascia through the femoral ring into the femoral canal
  • Atypical femoral hernias (rare)
    • Beclard's hernia: herniation through the saphenous opening and cribriform fascia into the superficial fascia of the thigh
    • Callisen's hernia (Cloquet's hernia): herniation into the thigh, behind the femoral vessels, and through the aponeurosis of the pectineus muscle
    • Narath's hernia (Teale's hernia, prevascular hernia): a hidden herniation in front of the femoral vessels
    • Serafine's hernia (retrovascular hernia): herniation into the thigh behind the femoral vessels
    • De Laugier hernia (Velpeau's hernia, lacunar ligament femoral hernia): herniation into the thigh through a congenital weakness in the lacunar ligament (Gimbernat ligament)
    • Hesselbach's diverticular hernia: secondary herniation lateral to the femoral vessels through the saphenous opening and cribriform fascia
    • Cooper's bisaccular hernia: secondary herniation through the femoral sheath
    • Cooper's femorogenital hernia: secondary herniation into the scrotum or labia majora due to a weakness of the inguinal skin fold

To remember the femoral triangle contents, think NAVEL: (from lateral to medial) femoral Nerve, Artery, Vein, Empty space (femoral canal → femoral hernia), Lymphatics


References:[4][2]

Clinical features

  • Non-complicated femoral hernia
    • A globular, subcutaneous swelling in the groin
      • Localization: inferior to the inguinal ligament, lateral to the pubic tubercle, and medial to the femoral vein
        • Unilateral in 80% of cases; bilateral in 20%
        • Rarely, the swelling may appear in atypical locations (see “Pathophysiology” above)
      • Swelling enlarges with coughing (palpable cough impulse) or a Valsalva maneuver
      • Occasionally, the swelling is reducible. After reduction, the following tests can be performed:
        • Finger invagination test: the inguinal canal is empty
        • Zieman's test: the expansile cough impulse is felt by the ring finger
        • Ring occlusion test: no swelling is seen on coughing
    • Possibly, non-specific, dragging pain
  • Complicated femoral hernia: see “Complications” below


References:[2][5]

Diagnostics

  • A femoral hernia is primarily a clinical diagnosis.
  • Groin ultrasound is used when the diagnosis is inconclusive (see “Differential diagnosis” below).
  • Abdominal CT is indicated if incarceration or strangulation are suspected (see “Complications” below)

Femoral hernias can be difficult to palpate in obese patients. US is indicated if an FH is suspected in this patient group!

References:[6]

Differential diagnoses

The differential diagnoses listed here are not exhaustive.

Treatment

  • Non-complicated femoral hernia: laparoscopic or open early elective surgical repair with mesh hernioplasty (tension-free repair)
  • Complicated femoral hernia: (see “Complications” below): open herniorrhaphy (non-mesh repair) using a McVay procedure

All femoral hernias should be surgically repaired because of the high risk of complications.

References:[7][8][9][10]

Complications

Reduction of a strangulated hernia should not be attempted because generalized peritonitis would occur following reduction of strangulated bowel loops!

Although femoral hernias account for only about 5% of all hernias, they account for about 40% of all complicated hernias! Approx. 25% of femoral hernias will become incarcerated and/or obstructed, and the cumulative 3-month and 2-year incidence of strangulation is about 10 times higher in femoral hernias than other inguinal hernias.

A femoral hernia should be considered among 40–70-year-old women presenting with signs of mechanical bowel obstruction!

References:[6][9][11][12]

We list the most important complications. The selection is not exhaustive.