Hernias in the groin may be either inguinal or, less commonly, femoral in origin.
The anatomy of the femoral canal is that the anterior border is the inguinal ligament, the posterior border is the pectineal ligament, the medial border is the lacunar ligament and the lateral border is the femoral vein.
In 2011/12 there were 3,790 primary femoral hernia repairs in NHS hospitals in England, based on hospital episode statistics. This compares with a respective figure of 69,313 for primary inguinal hernia repair. The majority of femoral hernia repairs (more than two thirds) are undertaken as emergency repairs.
Femoral hernias account for only around 5% of all abdominal hernias:
- Femoral hernias are more common in women than in men.
- The incidence is highest in middle-aged and elderly women, especially if parous.
- They are rare in children and account for about 1% of groin hernias. Sex incidence is equal. Diagnosis is often difficult.
- In elderly women the incidence of femoral hernia approaches that of inguinal hernia.
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- Presentation is as a lump in the groin, lateral and inferior to the pubic tubercle but a large hernia may bulge over the inguinal ligament and make differential diagnosis difficult.
- The hernia often appears or swells on coughing or straining and reduces in size or disappears when relaxed or supine.
- There may be a cough impulse.
- It may be possible to reduce the hernia.
- There may be associated lower abdominal pain if incarceration occurs.
- According to findings, the hernia may be classified as reducible, irreducible, obstructed or strangulated.
- Diagnosis is largely clinical, but is often missed due to lack of examination of the groin as part of abdominal assessment.
- Imaging techniques are helpful, with ultrasound scanning as first-line followed by CT scanning and MRI scanning.
The differentiation between inguinal and femoral hernia is not easy and doctors often get it wrong. Surgeons, including those in training, tend to be better than GPs but they too are far from perfect and so alternative criteria have been suggested:
- Traditionally it is taught that an inguinal hernia will lie above and medially to the pubic tubercle whereas a femoral hernia lies laterally and below.
- This is not strictly true, as the internal ring is always lateral to the femoral canal and a small indirect inguinal hernia will therefore be lateral to the pubic tubercle.
- Also, a direct hernia will be lateral to or above the pubic tubercle.
- A better test might be to place the finger over the femoral canal for reducible hernias and then ask the patient to cough. This landmark is easily felt either by following the adductor longus tendon to below the inguinal ligament and then placing one's fingers anteriorly and laterally to the tendon or, alternatively, palpating the femoral artery and placing one's hand approximately a finger's breadth medially to it.
- When the patient coughs, a femoral hernia should remain reduced while an inguinal hernia will reappear as an obvious swelling.
Other causes of lumps in the groin include:
- A lymph node in the groin, as with a lymphoma, chancroid or lymphogranuloma venereum.
- Ectopic testis.
- Psoas abscess.
- Psoas bursa.
The main concern with a hernia is strangulation.
- The risk of strangulation in a femoral hernia is 2% at 3 months and 45% at 21 months. This is very much greater than for an inguinal hernia.
- Only 50% of patients are aware of the hernia before strangulation.
- Around 60% of patients present in the emergency situation.
- If strangulation occurs, the lump will become red and tender as well as tense and irreducible.
- Other features include colicky abdominal pain, distension and vomiting, indicating a surgical emergency.
- Fluid and electrolyte imbalance must be corrected, followed swiftly by repair of the hernia.
- Failure to make a correct diagnosis is common.
- It is associated with a greater risk of needing bowel resection and a higher mortality.
In view of the high risk of strangulation, all femoral hernias should be repaired as an elective procedure, but as soon as possible. There is no place for a truss for a femoral hernia.
- There are three surgical approaches that can be used to access the femoral sac, each named eponymously. There is a low approach (called Lockwood's), a trans-inguinal approach (called Lotheissen's) and a high approach (called McEvedy's).
- Each technique has the principle of dissection of the sac with reduction of its contents, followed by ligation of the sac and closure between the inguinal and pectineal ligaments.
- The procedure can be open or performed laparoscopically.
- The abdominal wall can be reinforced with either stitches or use of a mesh, the latter being more common. A Cochrane review has reported that open mesh repair is associated with a reduced risk of recurrence.
- In those who are unfit for general anaesthesia, local anaesthetic may be used.
After hernia repair there is always a risk of recurrence but a mesh plug technique can reduce this.
A survey from Sweden examined the incidence of postoperative intestinal obstruction and found it low at 1.02 per 1,000. The risk was higher with a transabdominal laparoscopic approach than with a totally extraperitoneal laparoscopic hernioplasty but other factors, such as previous abdominal surgery, were more important.
The mortality for elective hernia repair, both inguinal and femoral is:
- 0.1% below the age of 60.
- 0.2% between 60 and 69.
- 1.6% between 70 and 79.
- 3.3% over the age of 80.
The risk for emergency repair of a strangulated hernia is 10 times higher and many patients are aged 80 years or over. The overall operative mortality for strangulated hernia is 10%:
- High age and the need to resect necrotic bowel increase the risk.
- The death rate from surgery for strangulated hernias has changed little over a 50-year period.
- Hence, femoral hernia must be repaired if at all possible, even in the elderly.
Further reading & references
- Nicks BA et al; Hernias, Medscape, Jun 2012
- Hospital Episode Statistics, Admitted Patient Care - England, 2011-12; The NHS Information Centre
- Sucandy I, Kolff JW; Incarcerated femoral hernia in men: incidence, diagnosis, and surgical management. N Am J Med Sci. 2012 Nov;4(11):617-8. doi: 10.4103/1947-2714.103343.
- Groin Hernias; Surgical Tutor
- Radcliffe G, Stringer MD; Reappraisal of femoral hernia in children. Br J Surg. 1997 Jan;84(1):58-60.
- Whalen HR, Kidd GA, O'Dwyer PJ; Femoral hernias. BMJ. 2011 Dec 8;343:d7668. doi: 10.1136/bmj.d7668.
- Hair A, Patterson C, O'Dwyer PJ; Diagnosis of a femoral hernia in the elective setting; J.R.Coll.Surg.Edinb., 46, February 2001, 117-18
- Gallegos NC, Dawson J, Jarvis M, et al; Risk of strangulation in groin hernias. Br J Surg. 1991 Oct;78(10):1171-3.
- Corder AP; The diagnosis of femoral hernia. Postgrad Med J. 1992 Jan;68(795):26-8.
- Scott NW, McCormack K, Graham P, et al; Open mesh versus non-mesh for repair of femoral and inguinal hernia. Cochrane Database Syst Rev. 2002;(4):CD002197.
- Dunn J, Day CJR; Local Anaesthesia for Inguinal and Femoral Hernia Repair; Practical procedures. Issue 4 (1994) Article 6
- Hachisuka T; Femoral hernia repair. Surg Clin North Am. 2003 Oct;83(5):1189-205.
- Bringman S, Blomqvist P; Intestinal obstruction after inguinal and femoral hernia repair: a study of 33,275 operations during 1992-2000 in Sweden. Hernia. 2005 May;9(2):178-83. Epub 2004 Nov 26.
|Original Author: Dr Hayley Willacy||Current Version: Dr Gurvinder Rull||Peer Reviewer: Dr Adrian Bonsall|
|Last Checked: 14/01/2013||Document ID: 2144 Version: 22||© EMIS|
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