Hernia
A hernia is the abnormal exit of tissue or an organ, such as the bowel, through the wall of the cavity in which it normally resides. The term is also used for the normal development of the intestinal tract, referring to the retraction of the intestine from the extra-embryonal navel coelom into the abdomen in the healthy embryo at about 7 weeks.
Various types of hernias can occur, most commonly involving the abdomen, and specifically the groin. Groin hernias are most commonly inguinal hernias but may also be femoral hernias. Other types of hernias include hiatus, incisional, and umbilical hernias. Symptoms are present in about 66% of people with groin hernias. This may include pain or discomfort in the lower abdomen, especially with coughing, exercise, or urinating or defecating. Often, it gets worse throughout the day and improves when lying down. A bulge may appear at the site of hernia, that becomes larger when bending down.
Groin hernias occur more often on the right than left side. The main concern is bowel strangulation, where the blood supply to part of the bowel is blocked. This usually produces severe pain and tenderness in the area. Hiatus, or hiatal hernias often result in heartburn but may also cause chest pain or pain while eating.
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. Predisposition to hernias is genetic and occur more often in certain families. Deleterious mutations causing predisposition to hernias seem to have dominant inheritance. It is unclear if groin 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. The diagnosis of hiatus hernias is often done by endoscopy.
Groin hernias that do not cause symptoms in males do not need immediate surgical repair, a practice referred to as "watchful waiting". However most men tend to eventually undergo groin hernia surgery due to the development of pain. For women, however, repair is generally recommended 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, laparoscopic surgery, or robotic-assisted 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. A hiatus hernia may be treated with lifestyle changes such as raising the head of the bed, weight loss and adjusting eating habits. The medications H2 blockers or proton pump inhibitors may help. If the symptoms do not improve with medications, a surgery known as laparoscopic Nissen fundoplication may be an option.
Globally in 2019, there were 32.53 million prevalent cases of inguinal, femoral, and abdominal hernias, with a 95% uncertainty interval ranging from 27.71 to 37.79 million. Additionally, there were 13.02 million incident cases, with an uncertainty interval of 10.68 to 15.49 million. These figures reflect a 36.00% increase in prevalent cases and a 63.67% increase in incident cases compared to the numbers reported in 1990. About 27% of males and 3% of females develop a groin hernia at some point in their lives. Inguinal, femoral and abdominal hernias were present in 18.5 million people and resulted in 59,800 deaths in 2015. Groin hernias occur most often before the age of 1 and after the age of 50. It is not known how commonly hiatus hernias occur, with estimates in North America varying from 10% to 80%. The first known description of a hernia dates back to at least 1550 BC, in the Ebers Papyrus from Egypt.
Pathogenesis
Most hernias happen when the muscles and tendons in the belly weaken or get damaged, which makes it hard for them to keep the insides in place and support the body properly. The belly and pelvis act like a container made of muscles, tendons and bones. When pressure builds up inside this container, the muscles push back to keep everything in place. If the pressure gets too high, it may cause the belly's wall to break, leading to a hernia. Once a hernia starts, it keeps enlarging, because the tension on the wall there increases.Epidemiology
About 27% of males and 3% of females develop a groin hernia at some time in their lives. In 2013 about 25 million people had a hernia. Inguinal, femoral and abdominal hernias resulted in 32,500 deaths globally in 2013 and 50,500 in 1990. Healthcare costs associated with abdominal wall hernias account for an annual expenditure of approximately 2.5 to 3 billion dollars.Signs and symptoms
Symptoms and signs vary depending on the type of hernia. By far the most common hernias develop in the abdomen when a weakness in the abdominal wall evolves into a localized hole, or "defect", through which adipose tissue, or abdominal organs covered with peritoneum, may protrude. Another common hernia involves the spinal discs and causes sciatica. A hiatus hernia occurs when the stomach protrudes into the mediastinum through the esophageal opening in the diaphragm.Hernias might manifest with pain in the area, a noticeable lump, or less specific symptoms caused by pressure on an organ stuck within the hernia, potentially leading to organ dysfunction. Typically, fatty tissue is the initial entrant into a hernia, but it might also involve an organ. Hernias are caused by a disruption or opening in the fascia, or fibrous tissue, which forms the abdominal wall. It is possible for the bulge associated with a hernia to come and go, but the defect in the tissue will persist.
Symptoms may or may not be present in some inguinal hernias. In the case of reducible hernias, a bulge in the groin or in another abdominal area can often be seen and felt. When standing, such a bulge becomes more obvious. Besides the bulge, other symptoms include pain in the groin that may also include a heavy or dragging sensation, and in men, there is sometimes pain and swelling in the scrotum around the testicular area.
Irreducible abdominal hernias or incarcerated hernias may be painful, but their most relevant symptom is that they cannot return to the abdominal cavity when pushed in. They may be chronic, although painless, and can lead to strangulation, obstruction, or both. Strangulated hernias are always painful and pain is followed by tenderness. Nausea, vomiting, or fever may occur in these cases due to bowel obstruction. Also, the hernia bulge, in this case, may turn red, purple or dark and pink.
In the diagnosis of abdominal hernias, imaging is the principal means of detecting internal diaphragmatic and other nonpalpable or unsuspected hernias. Multidetector CT can show with precision the anatomic site of the hernia sac, the contents of the sac, and any complications. MDCT also offers clear detail of the abdominal wall allowing wall hernias to be identified accurately.
Complications
Untreated hernia may be complicated by:- Inflammation
- Obstruction of any lumen, such as bowel obstruction in intestinal hernias
- Strangulation
- Hydrocele of the hernial sac
- Hemorrhage
- Autoimmune problems
- Irreducibility or incarceration, in which it cannot be reduced, or pushed back into place, at least not without very much external effort. In intestinal hernias, this also substantially increases the risk of bowel obstruction and strangulation.
Causes
Furthermore, conditions that increase the pressure of the abdominal cavity may also cause hernias or worsen the existing ones. Some examples would be: obesity, straining during a bowel movement or urination, chronic lung disease, and also, fluid in the abdominal cavity.
Also, if muscles are weakened due to poor nutrition, smoking, and overexertion, hernias are more likely to occur.
The physiological school of thought contends that in the case of inguinal hernia, the above-mentioned are only an anatomical symptom of the underlying physiological cause. They contend that the risk of hernia is due to a physiological difference between patients who have hernia and those who do not, namely the presence of aponeurotic extensions from the transversus abdominis aponeurotic arch. There isn't any proof that being physically active will cause a hernia to get stuck or make an existing hernia worse.
Abdominal wall hernia may occur due to trauma. If this type of hernia is due to blunt trauma it is an emergency condition and could be associated with various solid organs and hollow viscus injuries.
Diagnosis
Inguinal
By far, the most common hernias are inguinal hernias, which are further divided into the more common indirect inguinal hernia, in which the inguinal canal is entered via a congenital weakness at its entrance, and the direct inguinal hernia type, where the hernia contents push through a weak spot in the back wall of the inguinal canal. An indirect inguinal hernia and a direct inguinal hernia can be distinguished by their positioning in relation to the inferior epigastric vessels: an indirect hernia is situated laterally to these vessels, whereas a direct hernia is positioned medially to them. Inguinal hernias are the most common type of hernia in both men and women. In some selected cases, they may require surgery.There are special cases where a direct and indirect hernia appear together. A pantaloon hernia is a combined direct and indirect hernia when the hernial sac protrudes on either side of the inferior epigastric vessels.
Additionally, though very rare, two or more indirect hernias may appear together such as in a double indirect hernia.