A hernia is the medical term given to any condition where body tissues or organs (viscera) protrude out of the compartment of the body in which they normally reside. The most common use of this term refers to such protrusions arising from the abdominal cavity. The abdomen, which houses most of the gastro-intestinal tract and digestive organs (the bowels), is a roughly hexagonal box whose walls are composed of muscular sheets. Hernias tend to occur through weaknesses in this muscular wall. These areas of weakness may have been present from birth (congenital), and hernias develop as a result of severe straining, or automatically as the muscles get weaker with aging. Alternatively, hernia can occur after abdominal surgery which itself weakens the walls.

The most common complaint relating to hernia is the presence of a lump on the abdominal wall. Typically this appears on standing or straining (coughing, sneezing, lifting, etc), and can decrease in size or even disappear on lying flat, and can usually be gently pushed back into the abdomen. They can become quite uncomfortable and even painful to touch. It therefore becomes very difficult to perform normal physical activities, either for work or recreation in the presence of a hernia. If a hernia comes out in this way, but then gets stuck, it is referred to as an irreducible, or incarcerated hernia. There is a risk that a hernia, once incarcerated may cause its contents to compromise their blood supply. This becomes a potentially serious, life-threatening emergency known as a strangulated hernia, as the bowel contained within the hernia starts to die and disintegrate releasing toxins and bowel contamination. Strangulated hernias require emergency surgery. The risk of an incarcerated hernia becoming strangulated depends not so much on the size of the hernia itself, but the size of the abdominal wall weakness (defect) it arises from (the neck). The more narrow the neck, the greater the risk of strangulation. This is one reason why it is recommended that all hernia are repaired surgically if possible before this situation arises.

Specific names are given to the different kinds of common hernia seen, based on their anatomical location.

• Inguinal Hernia . This is the most common kind of hernia. The inguinal canal is the refers to a precise anatomical configuration of abdominal wall muscles around the groins and this area lies just above the skin creases between the top of the front of the thighs and the abdomen on each side. In men, the spermatic duct (vas deferens) as well as the blood vessels supplying the testicles pass through defects in the muscle layers of this region (the canal) to reach the scrotum (the testicle itself passes this way during embryonic development). This area therefore is one of potential, congenital weakness, and this form of hernia is much more common in men than women. Inguinal hernia can still occur in women, but the canal itself does not contain any major structures (only a fibrous, embryological remnant). Inguinal hernia are sometimes classified as direct or indirect depending on what part of they inguinal canal they arise from. There is a higher risk of incarceration and strangulation if the hernia is indirect. Both indirect and direct hernia can occur together. Inguinal can occur on the right or left sides individually (unilateral), but quite often, hernia are present on both sides (bilateral) though one side may be more painful than the other.
• Femoral Hernia . This name is given to the kind of hernia that arises also in the groin, but just below the skin creases. Again, this kind of hernia occurs across a congenital weakness, the femoral canal, which is a passageway through the pelvic bones at the lower end of the abdomen allowing the large blood vessels and nerves through to the lower limbs. The defect is triangular shaped, and at the most medial (inner) border is a space through which hernia occur. This kind of hernia is more common in women because of the shape of the pelvis. Because of the very small neck of this hernia, the risk of strangulation is much higher than other types of hernia.
• Umbilical and Paraumbilical Hernia . These refer to hernias that occur in and around the belly button, the location of where blood vessels entered the foetus during pregnancy. They tend to be quite painful, and have a moderate risk of incarceration.
• Epigastric (Ventral Hernia) These are usually small hernias that occur along the front middle of the abdomen, where the sheets of muscle from the left and right abdominal wall join together.
• Incisional Hernia. This is a special kind of hernia that occurs following a surgical procedure. Although after an operation, care is usually taken to repair the abdominal wall with strong stitches, this can breakdown after a period, and cause a defect and hernia. The most common types of operations that can cause incisional hernia are gynaecological operations, appendicectomy, and other major operations that used large (open, non-keyhole) incisions.
• Recurrent Hernia . Is the name given to any kind of hernia that has re-appeared, despite having been previously repaired surgically. Reasons for why this may have happened are discussed on the Hernia Surgery page.
• Hiatal (Hiatus) Hernia. Is an internal hernia which is described in detail with Reflux Disease.

The only definitive treatment for hernia is surgical repair. There has been a considerable change in the kind of hernia surgery available over the last two decades. Traditional techniques of hernia relied on using various configurations of stitches to repair the defects in the abdominal wall. The problem of these repairs was that the abdominal wall muscles themselves were to weak to hold the stitches, which simply tore through soon after the repair, causing a recurrent hernia.

In the early 1990’s, the concept of a tension-free repair gained acceptance, and variations on this principle are now virtually universal to all kinds of hernia repair. Instead of forcing the muscle together with heavy stitches, a prosthetic mesh (usually made of prolene and other synthetic materials) is placed over the defect and gently sutured or secured in place. The mesh acts as a frame for the ingrowth of cells called fibroblasts that lay down tough connective tissue. In this way, the defect is repaired without tension, and the abdominal wall permanently strengthened using the bodies’ own tissues, This kind of mesh repair seems to have a much lower recurrence rate that traditional suturing methods. In the last few years, it has become possible to repair hernia using keyhole surgery to place the mesh in position, but through much smaller incisions which also avoid the dissection and disruption of the normal abdominal wall muscles in order to reach the defect, yet maintain the principle of a tension free repair.

Laparoscopic Hernia Repair