Inguinal hernia

Inguinal hernias are protrusions of abdominal cavity contents through an area of the abdominal wall, commonly referred to as the groin, and known in anatomic language as the inguinal area or the myopectineal orifice. They are very common and their repair is one of the most frequently performed surgical operations. They usually arise as a consequence of the descent of the testis from the abdomen into the scrotum during early fetal life, and are therefore far more commonly seen in men than women. They present as painless bulges in the groin area that can become more prominent when coughing, straining, or standing up. The bulge commonly disappears on lying down. The presence of pain, or the inability to "reduce" the bulge back into the abdomen, usually indicates the onset of complications.

As the hernia progresses, contents of the abdominal cavity, such as the intestine, can descend into the hernia and run the risk of being strangulated within the hernia, causing an intestinal obstruction. If the blood supply of the portion of the intestine that is caught in the hernia is compromised, gut ischemia and gangrene can result, with serious consequences. The time of occurrence of complications is not predictable; some hernias can remain static for years, others can progress rapidly from the time of onset. Therefore, provided there are no serious co-existing medical problems, patients are advised to get the hernia repaired surgically at the earliest convenience after a diagnosis is made. Emergency surgery for complications such as obstruction and strangulation carry much higher risk than planned, "elective" procedures.

Despite the profusion of medical technology that is now available, the diagnosis of inguinal hernia rests on the history given by the patient and the physician's findings on examination of the groin. No tests are needed to confirm the problem.

Surgical correction of inguinal hernia is a simple operation that is now done in most places as an ambulatory or "day surgery" procedure. A workable technique of repairing hernia was first described by Bassini in the 1800s; the Bassini technique was a "tension" repair, one in which the edges of the defect are simply sewn back together without any reinforcement or prosthesis. Although tension repairs are no longer the standard of care due to their high recurrence rates, long recovery period and severe post-operative pain, a few tension repairs are still in use today; these include the Shouldice and the Cooper's/McVay repair.

Almost all repairs done today are open "tension-free" repairs that involve the placement of a synthetic mesh to strengthen the inguinal region; some popular techniques include the Lichtenstein repair (flat mesh patch placed on top of the defect), Plug and Patch (mesh plug placed in the defect and covered by a Lichtenstein-type patch), Kugel (mesh device placed behind the defect), and Prolene Hernia System (2-layer mesh device placed over and behind the defect). The meshes used are typically made from polypropyleneor polyester, although some companies market Teflonmeshes and partially absorbable meshes. The operation is typically performed under local anesthesia, and patients go home within a few hours of surgery, often requiring no medication beyond over-the-counter pain relievers such as aspirinor acetaminophen. Patients are encouraged to walk and move around immediately post-operatively, and can usually resume all their normal activities within a week or two of operation. Recurrence rates are very low - one percent or less compared with over 10% for a tension repair.

In recent years, much like in all other areas of surgery, laparoscopicrepair of inguinal hernia has emerged as an option. "Lap" repairs are also tension-free, although the mesh is placed within the preperitoneal space behind the defect as opposed to in or over it. As the evidence exists today, it has no proven superiority to the open method other than a slightly lower post-operative pain score. Unlike the open method, laparoscopic surgery requires general anesthesia. It is usually more expensive and consumes more OR time than open repair, carries a higher risk of complications, and most of all, has equivalent or higher rates of recurrence compared to the open tension-free repairs.

There are two types of inguinal hernia, direct and indirect. Femoral hernias, while they occur within the myopectineal orifice, are usually classed as separate from the "inguinal" hernias.

Indirect inguinal hernia

An indirect inguinal hernia protrudes through the inguinal ring and is ultimately the result of the failure of embryonic closure of the internal inguinal ring after passage through it of the testicleand the trailing supply of blood vessels and nerves which make up the spermatic cord. The internal ring, which is the beginning of the inguinal canal, was initially formed by the processus vaginalis, a fold of peritoneum which breaches the abdominal wall to make way for the descending testicle. In normal development, this processus is obliterated once the testicle is completely descended. When it remains open, a situation known as patent processus vaginalis, the stage is set for an indirect hernia.

An indirect hernia occurs when intra-abdominal contents, commonly including preperitoneal fatty tissues and intestines, traverse the ring to enter the inguinal canal. As time passes, the hernia contents may enlarge, extend the length of the canal, and even exit the canal through the external inguinal ring into the scrotum. During surgical repair, or herniorraphy, a surgeon recognizes the "indirect" hernia by noting that the hernia sac begins lateral to the inferior epigastric vessels, indicating that it arose at the top of the inguinal canal. Conversely, the "direct" inguinal hernia enters through a weak point in the fascia of the abdominal wall, and its sac is noted to be medial to these vessels.

Direct inguinal hernias

A direct inguinal hernia protrudes through a weakened area in the transversalis fascia within an anatomic region known as the medial or Hesselbach's triangle, an area defined by the edge of the rectus abdominis muscle, the inguinal ligamentand the inferior epigastric artery. While these hernias do not involve the inguinal canal directly, they do compromise the structures of the inguinal region. When a patient suffers a simultaneous direct and indirect hernia on the same side, the result is called a "pantaloon" hernia, and the defects can be repaired separately or together.

Theories of hernia formation

It was previously thought that hernias arose as the result of abnormal stress on the abdominal wall; this theory persists in the belief that hernias are caused by coughing too much or lifting heavy objects. Most researchers still point to a patent processus vaginalis or a failure of the abdominal wall "shutter" (an involuntary movement of the abdominal muscles that closes off the inguinal canal during increased intra-abdominal pressure) as the root cause of indirect hernias. Current research indicates that patients with direct inguinal hernias are heavily predisposed to herniate elsewhere, and that both direct and indirect hernias tend to run in families. As a result of these and other findings, a few researchers now believe that all direct hernias and many indirect hernias are a symptom of a congenital deficiency of collagen, the major structural fiber in connective tissue. Lack of collagen, according to this theory, results in weakened, attenuated connective tissue that cannot withstand the stresses of normal activity, and hence a hernia forms at the area of greatest weakness.de:Leistenbruch fr:Hernie inguinale it:Ernia inguinale nl:Liesbreuk

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It uses material from the http://en.wikipedia.org/wiki/Inguinal+hernia Wikipedia article Inguinal hernia.