DISCUSS THE EPIDEMIOLOGY OF INGUINAL HERNIA
An inguinal hernia is a protrusion of abdominal-cavity contents through the inguinal canal. Symptoms are present in about 66% of affected people. This may include pain or discomfort especially with coughing, exercise, or bowel movements. Often it gets worse throughout the day and improves when lying down. A bulging area may occur that becomes larger when bearing down. Inguinal hernias occur more often on the right than left side. The main concern is strangulation, where the blood supply to part of the bowel is blocked. This usually produces severe pain and tenderness of the area.
Risk factors for the development of a hernia include: smoking, chronic obstructive pulmonary disease, obesity, pregnancy, peritoneal dialysis, collagen vascular disease, and previous open appendectomy, among others. Hernias are partly genetic and occur more often in certain families. It is unclear if inguinal hernias are associated with heavy lifting. Hernias can often be diagnosed based on signs and symptoms. Occasionally medical imaging is used to confirm the diagnosis or rule out other possible causes.
Groin hernias that do not cause symptoms in males do not need to be repaired. Repair, however, is generally recommended in females due to the higher rate of femoral hernias which have more complications. If strangulation occurs immediate surgery is required. Repair may be done by open surgery or by laparoscopic surgery. Open surgery has the benefit of possibly being done under local anesthesia rather than general anesthesia. Laparoscopic surgery generally has less pain following the procedure.
EPIDEMIOLOGY OF INGUINAL HERNIA IN NIGERIA
The incidence of inguinal hernia in Nigeria is not new. About 27% of males and 3% of females develop a groin hernia at some time in their life. Groin hernias occur most often before the age of one and after the age of fifty. Inguinal, femoral and abdominal hernias resulted in 51,000 deaths in 2013 and 55,000 in 1990.
An inguinal hernia occurs when tissue pushes through a weak spot in your groin muscle. This causes a bulge in the groin or scrotum. The bulge may hurt or burn.
Most inguinal hernias happen because an opening in the muscle wall does not close as it should before birth. That leaves a weak area in the belly muscle. Pressure on that area can cause tissue to push through and bulge out. A hernia can occur soon after birth or much later in life. You are more likely to get a hernia if you are overweight or you do a lot of lifting, coughing, or straining. Hernias are more common in men. A woman may get a hernia while she is pregnant because of the pressure on her belly wall.
The main symptom of an inguinal hernia is a bulge in the groin or scrotum. It often feels like a round lump. The bulge may form over a period of weeks or months. Or it may appear all of a sudden after you have been lifting heavy weights, coughing, bending, straining, or laughing. The hernia may be painful, but some hernias cause a bulge without pain.
A hernia also may cause swelling and a feeling of heaviness, tugging, or burning in the area of the hernia. These symptoms may get better when you lie down.
Sudden pain, nausea, and vomiting are signs that a part of your intestine may have become trapped in the hernia. Call your doctor if you have a hernia and have these symptoms.
Signs and symptoms
Frontal view of an inguinal hernia (right).
Hernias present as bulges in the groin area that can become more prominent when coughing, straining, or standing up. They are rarely painful, and the bulge commonly disappears on lying down. The inability to “reduce”, or place the bulge back into the abdomen usually means the hernia is ‘incarcerated’ which requires emergency surgery.
Significant pain is suggestive of strangulated bowel (an incarcerated indirect inguinal hernia).
As the hernia progresses, contents of the abdominal cavity, such as the intestines, liver, can descend into the hernia and run the risk of being pinched within the hernia, causing an intestinal obstruction. If the blood supply of the portion of the intestine caught in the hernia is compromised, the hernia is deemed “strangulated” and gut ischemia and gangrene can result, with potentially fatal consequences. The timing of complications is not predictable. Emergency surgery for incarceration and strangulation carry much higher risk than planned, “elective” procedures. However, the risk of incarceration is low, evaluated at 0.2% per year. On the other hand, surgical intervention has a significant risk of causing inguinodynia, and this is why minimally symptomatic patients are advised to watchful waiting.
An incarcerated inguinal hernia as seen on cross sectional CT scan
A frontal view of an incarcerated inguinal hernia (on the patient’s left side) with dilated loops of bowel above.
There are two types of inguinal hernia, direct and indirect, which are defined by their relationship to the inferior epigastric vessels. Direct inguinal hernias occur medial to the inferior epigastric vessels when abdominal contents herniate through a weak spot in the fascia of the posterior wall of the inguinal canal, which is formed by the transversalis fascia. Indirect inguinal hernias occur when abdominal contents protrude through the deep inguinal ring, lateral to the inferior epigastric vessels; this may be caused by failure of embryonic closure of the processus vaginalis.
In the case of the female, the opening of the superficial inguinal ring is smaller than that of the male. As a result, the possibility for hernias through the inguinal canal in males is much greater because they have a larger opening and therefore a much weaker wall through which the intestines may protrude.
In men, indirect hernias follow the same route as the descending testes, which migrate from the abdomen into the scrotum during the development of the urinary and reproductive organs. The larger size of their inguinal canal, which transmitted the testicle and accommodates the structures of the spermatic cord, might be one reason why men are 25 times more likely to have an inguinal hernia than women. Although several mechanisms such as strength of the posterior wall of the inguinal canal and shutter mechanisms compensating for raised intra-abdominal pressure prevent hernia formation in normal individuals, the exact importance of each factor is still under debate. The physiological school of thought thinks that the risk of hernia is due to a physiological difference between patients who suffer hernia and those who do not, namely the presence of aponeurotic extensions from the transversus abdominis aponeurotic arch
Worldwide, inguinal hernia remains a common problem presenting to surgeons. At many hospitals in developing countries, the waiting period for admission is often long owing to long list of patients, limited bed spaces and inadequate qualified manpower. Day-case surgery for inguinal hernia is therefore the panacea to these many challenges.
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