What is a hernia?
A hernia is the protrusion of organs, such as intestines, through a weakened section of the abdominal wall. If left untreated, the split in the muscle widens and greater amounts of tissue or organs are pushed through the opening, forming a sac. This visible lump or bulge is one of the key characteristics of a hernia.
The weakened abdominal wall can be present at birth or may develop later in life. The most common site is the groin, but hernias can also form in other areas, such as the navel. If the lump can be gently pushed back through the abdominal wall, it is known as a reducible hernia. If the lump resists manual pressure, it is a non-reducible hernia, which can mean serious complications. Both forms of hernia require surgical repair. 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, 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.
What are the different types of hernia?
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 – occurring in the groin. This is the most common form, accounting for more than nine out of 10 hernias. A loop of intestine pushes against the small ring of muscle in the groin, eventually splitting the muscle fibres apart. Inguinal hernias affect more men than women and are particularly common in middle age.
- Femoral – occurring high on the thigh, where the leg joins the body. Similar to the events that cause an inguinal hernia, intestines force their way through the weak muscle ring at the femoral canal until they protrude. This herniated section of bowel is at risk of strangulation, which is a serious complication requiring urgent medical attention. Femoral hernias are more common in women.
- Umbilical or Ventral – a portion of the gut pushes through a muscular weakness near the navel, or belly button. This type of hernia is more common in newborns. Overweight women, or those who have had several pregnancies, are also at increased risk.
- Incisional – after abdominal surgery, the site of repair will always be structurally weaker. Sometimes, the intestines can push through the closed incision, causing a hernia.
- Strangulated Hernia – If the hernia resists manual pressure and can’t be popped back through the abdominal wall, it is known as a non-reducible hernia. This means that the intestinal loop is held tight by the muscular ring, which can lead to further swelling of the loop and eventual strangulation of the entrapped bowel. The femoral hernia is the most susceptible to this complication.
Symptoms of a strangulated hernia include nausea, vomiting and severe pain. Prompt medical attention and surgery is vital. Untreated, a strangulated hernia can lead to gangrene of the trapped bowel.
Surgical Procedures for Hernias
- Both reducible and non-reducible hernias need to be surgically repaired. The various procedures used depend on the location of the hernia, but may include opening the abdomen and using stitches and synthetic meshes to close and reinforce the weakened section of muscle.
- Inguinal, femoral and ventral hernias can often be repaired using laparoscopic surgery. A slender instrument known as a laparoscope is inserted and the hernia repaired from the inside. This eliminates the need for large abdominal incisions with fewer complications and quicker recovery.
- Large or complex incisional hernias may require a number of specialised techniques to close a difficult defect particularly if there have been multiple attempts to repair them previously. Often this requires an open cut combined with muscle relaxing incisions in the flank (known as a component separation) to fashion the repair.
Other factors that may have been contributing to the hernia, such as obesity and flabby muscle tone, also need to be addressed. However, the hernia returns in around one out of 10 cases, requiring subsequent surgery.