Hernias > Femoral Hernias

Femoral hernias are not very common, nonetheless are very important to diagnose because they have a high risk of developing complications such as bowel obstruction or strangulation.

Femoral hernias are found just below inguinal hernias. They can be misdiagnosed or missed on examination because they are found in an area where there are many other structures such as lymph glands.

The hernia develops and passes through a narrow passage or canal termed the femoral canal. This canal joins the pelvis to the groin. It is a quite short, tight canal and it is the tightness, which causes the high rates of complications.

Femoral hernias are relatively more common in women.

They appear as a swelling or lump together with pain. The swelling may come and go (reducible) but are usually not able to be reduced (irreducible).

As the hernia enlarges, it may be pushed upwards and this can make it difficult to tell the difference between inguinal hernia and a femoral hernia. Both hernias can be found together occasionally. Surgery is usually recommended for femoral hernia because of the higher risk of complications.

In the non-emergency case it is usually a simple operation requiring only a small cut just below the groin.

The procedure can be carried out using local anaesthetic under light sedation. The hernia is reduced or removed and then the defect closed with suturing or a mesh plug fixed into position.

Some surgeons use a higher approach through the groin or an even higher approach through the muscles of the abdominal wall.

These higher approaches may be used more frequently when the hernia has developed complications such as obstruction or strangulation.

The hernia may also be repaired using "keyhole" surgery – laparoscopic surgery.

Question and answer:

Can a femoral hernia be confused with other conditions?

Yes - can be confused with an inguinal hernia. Can be found together with an inguinal hernia also. In addition, other conditions, which occur in the same area, are:

- Large dilated varicose vein termed a saphena varix

- Lymph nodes – can enlarge in the groin signifying serious conditions such as a lymphoma or a tumour.

The most common cause of enlargement of glands in the groin is termed “reactive”. That means a reaction to an infection or inflammation from a condition such as an infected toenail. The source of infection is not always obvious.

Other conditions, which may occur in this region, are infected cysts, or an abscess.

All these conditions can usually be differentiated from each other by the history and the examination. But often tests are required. Simple tests for differentiation are an ultrasound, which will certainly differentiate between a hernia and a lymph node. The ultrasound can even help diagnose which condition is affecting the lymph node.

Where lymph nodes are enlarged and are a cause of concern, a needle can be placed into the node under ultrasound control and tissue taken out for histological examination or culture if an infection is suspected. Two types of needles can be used in – the very fine needle called needle aspiration cytology or thicker, true cut biopsy needles where a larger specimen is obtained and a more detailed analysis available.

As with any investigation, 100% reliability cannot be guaranteed. Thus, enlarged lymph nodes are sometimes removed surgically.

Clinical Example

This series of photos is interesting in that the patient presented six years following a right inguinal hernia repair with a painful swelling and felt that his hernia had come back. However an ultrasound was carried out which suggested that he had a femoral hernia and not a recurrence. Clinical examination verified the femoral hernia.

Hernias can be difficult to diagnose clinically because they are often present in overweight patients and can be difficult to find. In this case the lump was readily palpable.

The next question is usually, is it an inguinal or femoral hernia? In this case it was felt to be a femoral hernia because these present usually below and lateral to the pubic tubercle. However confusion can arise because femoral hernias ride up over the abdominal wall as they expand due to the covering of the deep fascia (scarpas) and thus can appear to be higher. Thus during the examination one should attempt to move it down as well.

The femoral hernia can be reducible or irreducible.

In this case it was an irreducible painful femoral hernia.

It is important in considering the diagnosis and operation to consider the anatomical landmarks.

In this case the femoral hernia presents through the femoral ring, which is medially bounded by the lacuna ligament and laterally by the femoral vein. Anteriorly is the inguinal ligament and posteriorly the pubic bone.

In all cases of abdominal pain the groin should be examined to exclude inguinale and femoral hernias. The femoral canal should be examined to ensure there is no femoral hernia because of the higher risk of strangulation.

Surgery can be performed with a variety of approaches. In this series one sees the low approach directly over the femoral canal.

The patient is examined standing. A bulge in the right groin can be seen and the scar of the inguinal hernia repair is seen.	CLINICAL TIPS: All patients with a hernia should be examined standing up then lying down. Both sides must be examined. All possible hernia sites should be examined The patient is asked to cough with their head turned away from the examiner and any cough impulse is noted. Then the hernia or swelling is palpated to confirm whether it is a hernia. Reduction is attempted by gentle pressure. In overweight patients the hernia may be difficult to see or even palpate. Both the external ring and the femoral canal can be examined withg the tip of the fingers and the patient coughing. Sometimes an squelch can be felt.
Lateral View	CLINICAL TIPS: A differential diagnosis should be considered. FEMORAL HERNIAS Inguinal hernia Lymph nodes Lipomata Abscess
Close up of the scar	CLINICAL TIPS: Femoral and inguinal hernias can occasionally occur together therefore must examine both sites, the inguinal canal and the femoral canal.
Patient in theatre recumbent and the surface markings shown. Transverse upper line is the previous incision. Triangle is the external ring. The swelling is outlined and the vertical lines are the femoral nerve, artery and vein. Note that the swelling overlies the vein.	CLINICAL TIPS: Note: The large femoral hernia expands and actually appears to be anterior to the femoral vein as well. This is important when making a surgical incision. Differential diagnosis of a strangulated femeral hernia is an abscess in the groin.
The hernia is exposed	SURGICAL TIPS: The femoral hernia looks just like a lump of fat. To expose the hernia the deep fascia of the thigh is divided. There may be venous tributaries of the long sapnenous vein or branches of the femoral artery such as the superficial epigastric. Lymph nodes may also be encountered.
	Hernia Exposed
Narrow neck demonstrated. Sac has been dissected free.	SURGICAL TIPS: Femoral hernias are very commonly irreducable and may easily strangulate. To reduce the hernia the surrounding fat is excised so that the sac can be gently manipulated back in.
Sac being demonstrated. Fat being dissected free. Sac is transfixed and excised or even maybe just reduced. Fat is excised.	SURGICAL TIPS: Femoral hernias are very commonly irreducable and may easily strangulate. To reduce the hernia the fat is removed and the sac is narrowed down. The contents must be reduced. The sac is then opened and by this stage the henria can be readily reduced. The sac is then transfixed and excised.
Mesh plug placed into femoral canal.	SURGICAL TIPS: Previously, femoral hernias were repaired by suturing. However, this causes tension with a higher rate of reccurence. There was also the risk of narrowing or injuring the femoral vein. Now a popular technique described by Lichtenstein is to insert a rolled up mesh like a cigarette. Commonly polypropylene. This avoids tension and is readily fixed into position with a low recurrence rate.
	Mesh plug fixed into positon

Conclusion

Thus, femoral hernias are not common compared to inguinal hernias. They occur relatively more frequently in females. Because of the narrow rigid walls of the femoral ring they are commonly irreducable and may readily strangulate. Thus, they should be repaired in most cases to avoid the risk of strnagulation and emergency surgery. They are sometimes confused with inguinal hernias and other lumps which may occur in the femoral triangle.