A hernia is the protrusion of internal fat or section of bowel through a weakened section of the abdominal wall. If left untreated, the split in the muscle widens and more of the bowel is pushed into the opening. A sac forms and a visible lump or bulge is either seen or felt on examination. This swelling is one of the key characteristics of a hernia.
The abdominal wall can have an inherent structural weakness from birth or a weakness may develop later in life. The most common site of herniation is the groin, but hernias can also form in other areas, such as the umbilicus (belly button) or develop due to an acquired structural weakness after an abdominal operation. If the hernia disappears when the patient lies down or the swelling can be gently pushed back through the abdominal wall, it is known as a reducible hernia. A hernia is said to be irreducible when the herniated sac cannot be returned manually to the abdominal cavity. This situation can have serious consequences and lead to obstruction and/or strangulation of the hernia contents.
Surgical repair is the only effective treatment for hernias. Approximately 40,000 Australians have their hernias surgically repaired every year, making this one of the most common operations.
Symptoms of a hernia
The symptoms of a hernia can vary depending on the location and severity, but may include:
- A visible lump or a swollen area.
- A heavy or uncomfortable feeling in the gut, particularly when bending over.
- Pain or aching at the site, particularly on exertion (such as lifting or carrying heavy objects).
- Digestive upsets, such as constipation.
- The lump disappears when the person is lying down.
- The lump enlarges upon coughing, straining or standing up.
Different types of hernias
The abdominal wall isn’t a solid sheet of muscle; it is made up of different layers. Certain areas are structurally weaker than others and therefore more likely to develop hernias. The different types of hernia include:
Inguinal – This is the most common form of hernia and accounts for 80% of hernia presentations. A loop of bowel presses against a weakness in the muscle wall in the groin eventually expanding the potential weakness in the muscle layer. The nearby internal tissues can then bulge into the opening. This is the most common form of hernia. This type of hernia is more common in men than women and more likely to occur in middle age but can present at any time.
Umbilical – This type of hernia usually occurs when internal fat pushes through a muscular weakness near the umbilicus or belly button. Although umbilical hernias are more common in newborns, women who have had several pregnancies or those who are obese are also at significant risk.
Incisional – This type of hernia develops in the scar of an abdominal surgical incision due to the muscles of the abdomen being compromised by the surgery. A section of bowel or other internal structures press against the weakened scar, separating the muscle fibres, and pushing through the incision, forming a hernia.
Femoral – This type of hernia is less common than the others and occurs high on the leg where the thigh joins the body. Its causes are similar to inguinal hernia where a loop of bowel forces its way through the weak muscle ring of the femoral canal until it protrudes and forms a swelling. This herniated section of bowel is at a high risk of strangulation. Femoral hernias are more common in women.
Obstruction and Strangulation
An obstructed hernia is one, which is irreducible but has no disruption to the blood supply. The loop of bowel becomes trapped and held tight by the surrounding muscles. Unless relieved this leads to further swelling and inflammation of the entrapped tissues.
A hernia is clinically assessed as "strangulated", when the blood supply of the herniated tissues is seriously impaired rendering gangrene of the affected loop of bowel imminent.
Symptoms of a strangulated hernia include nausea, vomiting and severe pain and tenderness at the site of the hernia.
Femoral and some incisional hernias are the most susceptible to this complication.
* This is a serious complication and requires urgent medical attention.
* Untreated, a strangulated hernia can lead to gangrene and death of the affected section of bowel.
Surgical procedures for a hernia
Surgery is the only effective treatment for all types of hernias. Irreducible hernias will need earlier intervention and management.
The various procedures used depend on the location of the hernia, but may include opening the abdomen and using stitches and nylon meshes to close and reinforce the weakened section of muscle. Without the use of mesh the risk of recurrence is high. Mesh is therefore the standard surgical option.
The procedure requires admission to hospital and a minimum stay of one night is usual.
Hernia repair is usually performed under general anaesthesia, however, in some cases inguinal and femoral hernias may be repaired under local anaesthetic.
Post- operative Complications
- Pain in the immediate post-operative period in all cases. Analagesics, prescribed by your surgeon, will be required for pain relief.
- Localised bruising and wound haematoma.
- Possible minor nerve injury in groin hernias.
- Infection – superficial or more significantly but less common, infection of the mesh.
- Recurrence will depend on the type of hernia and is much more common in the obese patient.
- Chronic post-op pain is uncommon and usually minor.
- Clear post-operative instructions may include a written sheet on leaving the hospital.
- A post-operative follow up at 2 weeks. If an appointment is not made at the time of discharge from hospital you will need to ring your surgeon’s rooms.
- Dressings are generally waterproof allowing you to shower but not to bath or swim. These will be left intact until you see the surgeon. If you have concerns regarding the dressings ring the surgeon’s rooms.
It is important that you take analgesics as advised in the early days to allow for a comfortable resumption of the basic activities of daily life.
- This should be discussed with your surgeon but is not advised for the first week post-op but may be resumed when you no longer need analgesics.
- Physical activity can be progressively expanded according to comfort. Graduated heavier activity may be slowly resumed depending on your progress as gauged by your post-operative review.
Specific questions relating to post-operative activity will need to be discussed at the hospital prior to discharge or with your surgeon before surgery.