Femoral hernia is the protrusion or bulge below the inguinal ligament, through the femoral canal, in the upper thigh. The rigid anatomy of the femoral canal predisposes these hernias to incarceration or strangulation, thus more than 44% of the cases of femoral hernia present in an acute setting with incarceration. Certain connective tissue diseases predispose the patients to developing femoral hernia. Femoral hernia is classified based on its anatomical relations on presentation. Most cases of femoral hernia present in females and the most common cause is an enlarged femoral ring. The female to male ratio is approximately 5 to 1. Femoral hernia must be differentiated from other diseases that cause swelling in the groin area. The diagnostic study of choice for femoral hernia is ultrasound, however in emergent cases that are difficult to diagnose CT scan is used to confirm the diagnosis. Surgery is the mainstay of treatment for femoral hernia. Immediate surgical intervention is needed in cases of incarceration or strangulation.

Hernia means a protrusion, hernias have been present in humans since the beginning of time, and the first interventions can be dated as early as the fifteenth century in ancient Egypt. However interventions had always been reserved for very large protrusions or painful incarcerated hernias.

Femoral hernia may be occasionally classified into several subtypes based on anatomical relation.

A femoral hernia is the protrusion of the hernia sac through the femoral ring in to the femoral canal. The anatomy of the femoral canal is such that the neck is made up of rigid structures that predispose herniated bowel to strangulation and incarceration. The hernia sac contains small bowel which can predispose to intestinal obstruction. Some connective tissue diseases predispose the patient to developing femoral hernia. Malignancy is very rarely associated with femoral hernias, thus histopathological analysis is done routinely following a repair but shows incarcerated bowel on most occasions.

The most common cause of femoral hernia is an enlarged femoral ring. Less common causes of femoral hernia include increased intra-abdominal pressure and pregnancy.

Femoral hernia must be differentiated from other diseases that cause swelling in the groin area, such as inguinal hernia, femoral artery aneurysm, saphenous vein varicosity, lymphadenopathy and lipoma.

The prevalence of femoral hernia is estimated to be 2% – 8% of all groin hernias. The incidence of femoral hernia increases with age, individuals commonly affected are between 40 -70 years of age. Females are more commonly affected than males.

Common risk factors in the development of femoral hernia include female gender, increasing age and a history of recurrent hernias.

There is insufficient evidence to recommend routine screening for femoral hernia.

If left untreated, 44%-86% of patients with femoral hernia may progress to develop strangulation or incarceration.

Ultrasound is the diagnostic study of choice for diagnosing femoral hernia as it has low cost, widespread availability and low risk of radiation exposure. If it is an emergent case with signs of incarceration that is difficult to diagnose based on clinical examination, an abdominal CT scan must be performed to confirm the diagnosis.

The majority of patients with femoral hernia are asymptomatic. Most common symptom is swelling below the inguinal ligament. Emergent cases may present with signs of incarceration; abdominal pain, nausea, vomiting.

Patients with femoral hernia usually appear normal. Physical examination of patients with femoral hernia is usually remarkable for swelling or lump below the inguinal ligament. It is a difficult diagnosis and maybe impossible to differentiate from inguinal hernia. If incarceration is present, the swelling or lump maybe tender.

There are no diagnostic laboratory findings associated with femoral hernia.

There are no x-ray findings associated with femoral hernia. However, an x-ray KUB may be helpful in the diagnosis of complications of femoral hernia, which include incarceration.

Although the diagnostic study of choice for femoral hernia is ultrasound, abdominal CT scan may be helpful in the diagnosis of femoral hernia. Findings on CT scan suggestive of femoral hernia include bowel dilation, mesangial thickening and bowel strangulation. Due to the radiation exposure and high cost it is not used a s first line diagnostic tool. In emergent cases that are difficult to diagnose, abdominal CT scan can be used as a first line diagnostic tool.

The diagnostic study of choice for femoral hernia is ultrasonography, but abdominal MRI may be helpful in the diagnosis of femoral hernia. It provides the best anatomic detail, helps differentiate inguinal hernia from femoral hernia and has a sensitivity and specificity greater than 95%. Due to the high cost and lack of uniform availability it is not used as the diagnostic study of choice.

Ultrasound may be helpful in the diagnosis of femoral hernia. Findings on an ultrasound suggestive of femoral hernia include thickening and edema of the intestinal wall, slightly echogenic, long strip shaped omentum in the hernia sac.

The definitive therapy for femoral hernia is surgery. Medical therapy is given to patients in preparation for surgery and postoperatively to prevent complications. Patients with pre and post operative pain should be treated with NSAID as a baseline analgesia. Patients with strangulated femoral hernia should be given broad spectrum antibiotics that cover both aerobic and anaerobic gram negative organisms.

Surgery is the mainstay of treatment for femoral hernia. Immediate surgical intervention is indicated in cases of incarceration or strangulation. The two popular surgical techniques are McVay repair and Lichenstein mesh repair. There is increased morbidity and mortality with surgical intervention in cases of strangulation or incarceration but it is still indicated. McVay repair is recommended in cases of intestinal incarceration as there is increased risk of infection following mesh repair in such cases.

Effective measures for the primary prevention of femoral hernia include optimal weight management, avoidance of rapid weight loss, use of good body mechanics while lifting heavy objects.

Effective measures for the secondary prevention of femoral hernia include avoiding activities that increase intra-abdominal pressure, preventing constipation and usage of monofilament stainless steel wire for suturing after surgical repair.

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Hernia means a protrusion, hernias have been present in humans since the beginning of time, and the first interventions can be dated as early as the fifteenth century in ancient Egypt. However interventions had always been reserved for very large protrusions or painful incarcerated hernias.

There is a long history of the development of femoral hernia repair and the most notable transitions include:^[1]

• The femoral approach was favored in the 19th century by renowned surgeons Bassini, Marcy and Cushing. The recurrence rate was very high.
• The inguinal approach was then favored by a renowned surgeon named Chester McVay, though the recurrence rate still remained high, there were a number of complications and patients were unable to resume daily activities.
• The plug technique was first introduced by Irving Lichtenstein and it was improvised by Gilbert and Rutkow.
• Presently, the widely used method is the PerFix mesh plug technique, which has fewer complications, patients are discharged in one day, and resume daily activities soon after.

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Femoral hernia may be classified into several subtypes based on anatomical relation.

Femoral hernia may be occasionally classified into several subtypes based on anatomical relations:^{[1][2][3][4][5]}

Sub-classification	Location and relations
Cloquet’s hernia	Emerges through the pectineal fascia
Hesselbach’s (lateral) hernia	Lateral to the inferior epigastric and femoral vessels
Velpeau’s hernia	Prevascular-anterior to the femoral vessels
Serafini’s hernia	Retrovascular-posterior to the femoral vessels
De Garengeot hernia	Contains the appendix
Littre hernia	Contains a Meckel’s diverticulum
Laugier’s hernia	Develops through the lacunar ligament

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A femoral hernia is the protrusion of the hernia sac through the femoral ring into the femoral canal. The anatomy of the femoral canal is such that the neck is made up of rigid structures that predispose the herniated bowel to strangulation and/or incarceration. The hernia sac contains small bowel which can predispose to intestinal obstruction. Some connective tissue diseases predispose the patient to developing femoral hernia. Malignancy is very rarely associated with femoral hernias, thus, histopathological analysis is done routinely following a repair but shows incarcerated bowel on most occasions.

• Pelvicrural interval, an opening from the abdomen to the thigh, is divided into two spaces:^[2]
  • Lacuna musculosa (lateral space), as the name suggests the iliopsoas muscles pass through this space.
  • Lacuna vasculosa (medial space), as the name suggests, is the passage for the femoral vessels.
• In the pelvis, along the anterior surface of the iliopsoas muscles run the external iliac vessels.^[3]
• The external iliac vessels pass between the iliopubic tract and Cooper’s ligament, and then under the inguinal ligament to become the femoral vessels.^[3]
• As the external iliac vessels pass along the lacuna vasculosa, they are covered by the transversalis fascia forming the femoral sheath.^[3]
• The femoral sheath extends 4cm caudally to become the adventitia of the femoral vessels.^[3]
• The femoral sheath has a medial compartment that is known as the femoral canal.^[3]
• The femoral canal is less than 2 cm in diameter and it contains lymphatics and glands.^[3]
• The true opening of the femoral canal is a musculoaponeurotic ring that consists of:^[4]
  • Cooper’s ligament inferiorly
  • Femoral vein laterally
  • Iliopubic tract superiorly and medially
• The medial boundary of the femoral ring is made up of the lateral edge of the transversus abdominis muscle aponeurosis insertion with the transversalis fascia onto the pubis.^[4]
• The true inner ring of the femoral canal is bounded by:^[5]
  • The iliopubic tract anteriorly and medially
  • The Cooper’s ligament posteriorly
• The distal orifice (neck of the femoral canal) has a rigid boundary which is usually less than 1 cm in diameter and is surrounded by:^[6][7]
  • The lacunar ligament medially
  • The inguinal ligament anteriorly
  • Fascia of the pectineal muscle posteriorly
• The rigidity of the structures forming the boundary of the neck of femoral canal results in femoral hernias’ strangulation.

• A femoral hernia is the protrusion of the peritoneal sac through the femoral ring in to the femoral canal, posterior and inferior to the inguinal ligament, and it is medial to the femoral vessels.^[8]
• The hernia sac may contain preperitoneal fat, omentum or small bowel.^[8]
• Femoral hernias typically have a narrow neck, which predisposes them to incarceration and the need for emergent surgery.^[8]
• De Garengeot hernia is a type of femoral hernia that contains the appendix.^[9]
• Littre hernia is an uncommon type of femoral hernia that contains a Meckel’s diverticulum.^[9]

• First degree relatives of patients with inguinal hernia are more susceptible to developing femoral hernia.^[10][11]

• Ehlers-Danlos syndrome^[10][12][13]
• Appendicitis^{[9][14][15][16]}
• Meckel’s diverticulum^[17][9][18]
• Intestinal obstruction^[18]
• Intestinal volvulus^[18]
• Intussusception^[18]

• On gross pathology, incarcerated bowel is a characteristic finding of femoral hernia.^[19]

• It is recommended that femoral hernia specimens should be submitted for microscopic histopathological analysis, though it is very rare to find a malignant lesion in a femoral hernia sac.^[19]

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The most common cause of femoral hernia is an enlarged femoral ring. Less common causes of femoral hernia include increased intra-abdominal pressure and pregnancy.

• Life-threatening causes include conditions which may result in death or permanent disability within 24 hours, if left untreated. There are no life-threatening causes of femoral hernia, however complications resulting from untreated femoral hernia is common.

Femoral hernia may be caused by:^[1][2]

• An enlarged femoral ring
• A non-existent iliopubic tract or pectineal ligament
• A narrow posterior inguinal wall attachment on to the pectineal ligament

Less common causes of femoral hernia include:^[3]

• Increased intra-abdominal pressure
• Pregnancy

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Femoral hernia must be differentiated from other diseases that cause swelling in the groin area, such as inguinal hernia, femoral artery aneurysm, saphenous vein varicosity, lymphadenopathy and lipoma.

Femoral hernia must be differentiated from other diseases that cause swelling in the groin area. The differentials include the following:^{[1][2][3][4][5][6][7][8][9][10][11][12][13]}

Diseases	History and Symptoms					Physical Examination			Imaging
	Swelling	Pain	Nausea	Vomiting	Age/Gender	Location of swelling	Tenderness	Pulsatile mass	Ultrasonography
Femoral hernia	+	+/-	+/-	+/-	Female > 45yrs	Below the inguinal ligament	+/-†	–	Slightly echogenic, long strip shaped omentum in the hernia sac. In cases of incarceration, expansion of a fluid filled bowel, intestinal fluid reflux and thickening and edema of intestinal wall.
Inguinal hernia	+	+	+/-	+/-	Male > 40yrs	Above the inguinal ligament	+/-†	–	Abnormal ballooning of the anteroposterior diameter of the inguinal canal
Femoral artery aneurysm	+	–	–	–	Male > 60 yrs	Usually below the inguinal ligament	–	+	Duplex ultrasound used to differentiate between femoral artery aneurysm and femoral hernia
Saphenous vein varicosity	+	+/-	–	–	Female	Sephanofemoral junction (inferolateral to the pubic tubercle)	–	–	Duplex ultrasound determines the pattern of venous incompetence and reflux.
Lymphadenopathy	+	+/-	–	–	Male and female	Femoral canal (medial to femoral vessels)	–	–	Internal echo in cases of lymphadenopathy
Lipoma	+	+/-	–	–	Male and female 40-60 yrs	Occurs any where throughout the body	+/-	–	Echogenic solid mass, often misinterpreted as a fat containing hernia.

†In cases of incarceration or strangulation, tenderness can be present.

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The prevalence of femoral hernia is estimated to be 2% – 8% (2000 per 100,000 cases to a high of 8000 per 100,000 cases) of all groin hernias. The incidence of femoral hernia increases with age, individuals commonly affected are between 40 -70 years of age. Females are more commonly affected than males.

• The prevalence of femoral hernia is estimated to be 2% – 8% (2000 per 100,000 cases to a high of 8000 per 100,000 cases) of all groin hernias.^[1][2]

• The incidence of femoral hernia increases with age; the peak age at diagnosis is 50 years.^[3]
• Femoral hernia commonly affects individuals between 40 – 70 years of age.^[3]

• Females are more commonly affected by femoral hernia than males. The female to male ratio is approximately 5 to 1.^[4][5][3]

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Common risk factors in the development of femoral hernia include female gender, increasing age and a history of recurrent hernias.

• Common risk factors in the development of femoral hernia include female gender, history of recurrent hernias, increasing age.^[1]

• Common risk factors in the development of femoral hernia include:^[1]
  • Female gender
  • Increasing age
  • History of recurrent hernias

• Less common risk factors in the development of femoral hernia include:^[2][3]
  • Smoking
  • Lower body mass index
  • Collagen vascular disease
  • Ehlers-Danlos syndrome

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There is insufficient evidence to recommend routine screening for femoral hernia.

There is insufficient evidence to recommend routine screening for femoral hernia.

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If left untreated, 44%-86% of patients with femoral hernia may progress to develop strangulation or incarceration.

• Femoral hernias may be small and asymptomatic during early course of the disease.
• Some individuals may have the hernia for decades without seeking medical care because of asymptomatic initial disease course.
• If left untreated, 44%-86% of patients with femoral hernia may progress to develop strangulation or incarceration.^[1][2]
• Strangulation or incarceration may lead to bowel necrosis, causing pain, erythema, nausea, vomiting and fever.

• Common complications of femoral hernia include:^[3][4][5][6]
  • Strangulation or incarceration
  • Bowel obstruction
  • Intestinal necrosis

• Prognosis is good, if surgery is performed in time (before the development of complications).^[1][5]
• The presence of bowel obstruction is associated with a particularly poor prognosis among patients with femoral hernia.^[1][5]

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