What is an inguinal and femoral hernia?

A hernia is the protrusion of tissue through an opening in the surrounding wall of the cavity that normally contains it. Because of this weak spot of the wall, an organ or a part of an organ squeezes through and reaches another region of the body. If this region is the groin, the area between the abdomen and the upper thigh on either side of the body, we call the hernia inguinal (inner groin) or femoral (outer groin).

In case of an inguinal hernia, the protrusion of abdominal-cavity contents occurs through the inguinal canal, a condition very common in men. Femoral hernias develop underneath the inguinal canal into the upper thigh, through a naturally occurring weakness called the femoral canal. They occur more frequently in women.

There are two types of inguinal hernias, indirect and direct. Indirect inguinal hernias protrude through the deep inguinal ring (the natural entrance to the inguinal canal) and are often the result of the failure of embryonic closure / narrowing of this entrance after the testicle passes through it. Direct inguinal hernias develop through a weak spot of the back (posterior) wall of the inguinal canal, the transversalis fascia.

Inguinal canal

The inguinal canal is an approximately 4 cm long natural passage among the muscle layers of the abdominal wall in the groin, the area between the abdomen and the upper thigh. It connects the abdominal cavity with the scrotum (the protuberance that contains the testicles in men) or the labia majora (in women). During development the testicles descend through the inguinal canal on each side into the scrotum.

The inguinal canal contains various anatomical structures: blood vessels, lymphatics, nerves, ductus deferens etc., forming the spermatic cord in men. In women the inguinal canal contains the round ligament of the uterus, instead of the spermatic cord.

Femoral canal

The femoral canal is an approximately 2 cm long conical shaped area underneath the inguinal canal in the outer groin. It's located next (medial) to the major blood vessels of the leg, the femoral vein and the femoral artery. It usually contains lymphatic vessels and a lymph node embedded in connective tissue.

Inguinal hernia repair: a very common procedure with controversial management

Inguinal hernia repair is one of the most commonly performed surgical procedure in the world, as inguinal hernias occur in about 15% of the population. Despite the fact, that inguinal hernia repair is an essential part of a general surgeon's repertoire of operations, the definitive operative management still remains controversial. Numerous different surgical techniques have been developed over the years, some are today very popular, while others are considered obsolete.

Tension-free mesh repair is today gold standard in adult inguinal hernia repair

Multiple studies have confirmed that surgical techniques using tension-free mesh repair have significant advantages over techniques using stitching under tension, such as Bassini and Shouldice suture repairs. So, the question about the best way to close and reinforce an inguinal hernia defect seems to have been resolved and most surgeons, including us, prefer to perform a tension-free mesh repair to our adult patients.

Method description
The Lichtenstein technique is an open, tension-free inlay mesh repair for indirect and direct inguinal hernias.

Under general, regional, or local anesthesia a single 5-7 cm long skin incision is made above the hernia in the groin. After dissection, inversion or removal of hernia sac, a synthetic mesh implant is placed among the muscle layers, that form the inguinal canal, on top of the abdominal wall defect to fix it as a patch.

A reliable method
Lichtenstein belongs nowadays to the standard procedures, that most surgeons learn during their surgical training and perform later on their patients. Soon after this technique was introduced, it became very popular and practically replaced older procedures, that use sutures under tension to fix the hernia defect, as the hernia recurrence rate was significantly lower and the patient comfort after surgery significantly higher. We have been performing Lichtenstein for many years and we can confirm, that it is a reliable technique with good clinical results.

Downsides
However, as mentioned above, Lichtenstein is an inlay technique: the mesh is placed and fixed among the muscles of the abdominal wall, that form the inguinal canal. Unfortunately, there are some nerves in exactly the same area, where the mesh is usually placed. As a result, an annoying, long-lasting pain can rarely occur after Lichtenstein repair, because of a chronic irritation of those nerves. Moreover, the mesh inside the inguinal canal provides no protection for future femoral hernias, that can occur underneath the canal (and the mesh) into the outer groin / thigh.

Two different laparoscopic procedures for inguinal hernia repair haven been established: TAPP and TEP.

FAQ: I heard that keyhole surgery is usually better than open surgery. What about inguinal hernia repair?

TAPP
The TAPP (TransAbdominal PrePeritoneal) approach allows the inguinal hernia repair through the abdominal cavity (transabdominal). Under general anesthesia the abdomen is inflated with CO2 gas and a camera (laparoscope) is inserted through an incision in or just below the navel. The necessary special instruments to repair the hernia are inserted through other small incisions in the lower abdomen. The peritoneum, the membrane that forms the lining of the abdominal cavity, is then opened so that the surgeon can repair the hernia. After placing the mesh implant above it (preperitoneal), the peritoneum is closed again.

TEP
The TEP (Totally ExtraPeritoneal) approach allows the inguinal hernia repair without accessing the abdominal cavity (extraperitoneal). Through an incision just below the navel under general anesthesia, the surgeon reaches the preperitoneal space (the space between the peritoneum and the muscles of the abdominal wall), inflates it with CO2 gas and inserts a camera (laparoscope). The necessary instruments are also inserted to the inflated preperitoneal space, through smaller incisions in the lower abdomen. This way, the surgeon can repair the hernia and place the mesh implant above the peritoneum (preperitoneal), without entering the abdominal cavity.

Advantages of laparoscopic hernia repair
We always felt, that the placement of a mesh below the muscle layers (sublay or preperitoneal) provides the best bio-mechanics for a hernia repair. This fact has already been proven for other types of hernias by clinical trials. Therefore, we were delighted as laparoscopic approaches to hernia repair were developed and implemented. The do namely just that: they allow the preperitoneal (sublay) placement of the mesh implant, which results in an increased stability of the hernia repair during physical load. Patients are able to return to their full activities much more quickly than they would after open Lichtenstein repair. As the mesh is placed preperitoneal and the area, where the inguinal nerves run, is avoided, the risk of chronic pain may decrease. Moreover, the laparoscopic inguinal hernia repair is at the same time suitable for femoral hernias, that develop underneath the inguinal ligament into the outer groin / thigh. Furthermore, the TEP and TAPP procedures seem to be better for repairing a recurrent inguinal hernia after open surgery and they are preferred for bilateral (two-sided) inguinal hernias, as the repair of both sides can be performed at once.

Those are the main advantages of the laparoscopic inguinal hernia repair techniques over the open Lichtenstein procedure. Other well known benefits of the laparoscopy over open surgery are in case of inguinal hernia repair, unlike other surgical procedures, not as significant: the pain and discomfort after surgery may be in case of laparoscopic inguinal hernia repair slightly less; it may also be more appealing for cosmetic reasons but also the incision made during open Lichtenstein mesh repair is small anyway and it heals well without a particularly visible scar in most cases.

Disadvantages of laparoscopic hernia repair
Laparoscopic inguinal hernia repair techniques, especially the TEP procedure, are technically demanding for the surgeon and require high experience and expertise. The duration of the operation is always longer compared with open inguinal hernia repair.

In fact, the advantages mentioned above only apply, if a well-trained laparoscopic surgeon performs the operation in a surgical department, specialized in laparoscopic hernia repair. Otherwise, the results can be much worse and the consequences serious: increased risk of major organ damage or bleeding, much higher risk of an early recurrence of the hernia, prolonged operation times under general anesthesia etc.

We have been performing TEP for years and we can confirm, that the learning curve for a surgeon is several hundred procedures indeed.

Another disadvantage of laparoscopic inguinal hernia repair, is the fact that the procedure is only possible under general anesthesia. On the other hand, open inguinal hernia repair can be performed under general, regional or local anesthesia. Although general anesthesia is nowadays very safe, it still carries risks on its own.

Latest development
Several years ago, we too joined forces with many other surgeons around the world, in order to improve the inguinal and femoral hernia repair, by combining the advantages of the open and the laparoscopic procedures available and leaving out their downsides. The result was the development of safe and simple (to learn and apply) tension-free surgical techniques, which allow the placement of a mesh into the preperitoneal space behind the transversalis fascia (sublay), just like the laparoscopic methods, but not necessarily in general anesthesia.

Although there are some variations of the open preperitoneal inguinal hernia repair available (Kugel, ONSTEP, transinguinal etc.), the basic principles and advantages remain the same. As they become more popular, the open preperitoneal techniques are rapidly replacing the widespread conventional open and laparoscopic procedures.

Method description
A single small skin incision is made at the groin / lower abdomen. Using minimal tissue preparation, the inguinal (or femoral) hernia is inverted or removed. The surgeon then enters the preperitoneal space (the space between the membrane that forms the lining of the abdominal cavity and the muscles of the abdominal wall) and places a special designed mesh implant inside that space. As the total surface area / size of the mesh covering the hernia defect is much greater than the size of the incision, the mesh is first folded and then expanded inside the preperitoneal space. The special design of the mesh allows this expansion.