Inguinal Hernia

Introduction

When a bulge occurs in the groin area present between the thigh and the lower abdominal area, it is known as an inguinal hernia. When the lower abdominal muscles become weak, it can result in an inguinal hernia. Intestines are protected in the lower abdomen by three layers. The first layer is the peritoneum which is thin. The second layer is composed of abdominal muscles and the third outermost layer is the skin. When the peritoneum and the intestines push through the abdominal muscle layer and form a bulge under the skin, an inguinal hernia develops (1).

The formation of this hernia can be dangerous due to its tendency to keep getting bigger. Because of this, intestines can get confined inside this bulge losing their supply of blood. Such a condition is called a strangulated inguinal hernia and this problem can only be corrected with the help of surgery. Inguinal hernias may form either on one side of the body or on both sides. The presence of inguinal hernia is found to be more in males than females. Inguinal hernias can be direct and indirect. The indirect inguinal hernia is the type abundantly found and developing at any age with a frequency more in males. The prevalence is more in infants. The direct inguinal hernia is more common in adults and can develop over time due to the weakening of the abdominal muscles.

Pathology

An inguinal hernia develops when the intestine, the bladder, or omentum come through into the inguinal canal. The viscera of the abdomen descend from the abdomen through the inguinal ring in indirect inguinal hernia and follow the round ligament in women or spermatic cord in men. The descended viscera then appear at the external ring and spread further down in the inguinal canal reaching the labia or scrotum. While in a direct inguinal hernia, the viscera do not enter the inguinal canal by way of the internal ring. Instead, the abdominal viscera makes its way through the dorsal inguinal wall, sticking out directly by way of the transverse fascia of the canal. This area is known as Hesselbach’s triangle and exists at the external ring (3).

Features

Usually, there is a swelling in the groin region. When the patient strains or stands, a lump appears over the herniated region and the lump is absent when the patient acquires the supine position. Other associated symptoms include vomiting, nausea, constipation, discomfort, or pain in the abdominal region indicating obstruction or strangulation (5).

Diagnosis

By and large, the diagnosis of inguinal hernias are mainly on the basis of physical examination and thorough history. When more information is required, help can be taken from radiologic investigations. Radiologic modalities such as computed tomography (CT), ultrasonography (US), and magnetic resonance imaging (MRI) can be used. CT scan is mainly used in patients showing symptoms of strangulation or obstruction or in the case when a certain diagnosis cannot be reached. MRI scanning is rarely used (4).

Treatment

The ultimate treatment of inguinal hernia is through surgical repair. It is a general rule to repair all the symptomatic inguinal hernias when possible. Surgical repair of inguinal hernia can be performed in two ways. An open surgery in which a cut is made through which the lump is pushed into the abdominal cavity. A laparoscopic or keyhole surgery which is a less invasive technique involves making several small cuts through which a laparoscope is inserted. A laparoscope is a thin tube containing a camera at its tip. The instruments are used to carefully repair hernia while the camera gives magnified images to the doctor (6).

Sources

1. NHS. Hernia [Internet]. nhs.uk. 2017 [cited 2022 Jul 15]. Available from: https://www.nhs.uk/conditions/hernia/
2. John Hopkins Medicine. Inguinal Hernia [Internet]. 2021 [cited 2022 Jul 15]. Available from: https://www.hopkinsmedicine.org/health/conditions-and-diseases/hernias/inguinal-hernia
3. Inguinal Hernia – Atlas of pathophysiology, 2 Edition [Internet]. [cited 2022 Jul 15]. Available from: https://doctorlib.info/physiology/pathophysiology/81.html
4. Hammoud M, Gerken J. Inguinal Hernia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Jul 15]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK513332/
5. Morrison Z, Kashyap S, Nirujogi VL. Adult Inguinal Hernia. In: StatPearls [Internet]. Treasure Island (FL): StatPearls Publishing; 2022 [cited 2022 Jul 15]. Available from: http://www.ncbi.nlm.nih.gov/books/NBK537241/
6. NHS. Inguinal hernia repair [Internet]. nhs.uk. 2017 [cited 2022 Jul 15]. Available from: https://www.nhs.uk/conditions/inguinal-hernia-repair/