Hernia
What is a Hernia?
A hernia is defined as the protrusion of an organ from it’s original cavity to another body cavity. Commonly, this is the protrusion of fat or bowel from the abdominal cavity to the subcutaneous tissue secondary to a weakness in the abdominal wall musculatures.
Intra-abdominal (inside the abdomen) pressure pushes the peritoneum (lining of abdominal cavity) through the weakness and forms a bulge under the skin. This is called a “hernia sac” and may start small which is obvious when standing/straining (such as sneezing or coughing) but disappears when lying down.
Hernias are often detected as an incidental finding and asymptomatic. However, hernias typically increase in size and become larger due to abdominal pressure pushing the intra-abdominal content (fat, bowel) into the hernia. The hernia can get stuck (incarcerated) or ischemic (strangulate) which requires immediate specialist input. Due to these reasons, most hernias require surgical intervention to prevent potential complications and relieve symptoms.
Causes of Hernia
In many patients, there is no obvious cause for the development of a hernia. There are natural spots of potential weakness in the abdominal wall/musculature and hernias can develop due to strain on the abdominal wall. Hernia can develop at any age and affects both genders. However, hernias do occur more commonly in men and in the older age group.
There are certain risk factors for the development of a hernia:
Increased abdominal pressure
- Abdominal straining particularly heavy activity/lifting
- Chronic cough
- Obesity
- Physical exertion
- Peritoneal dialysis
- Ascites (accumulation of abdominal fluid)
Impaired abdominal muscle strength and healing
- Smoking
- Poor nutrition
Signs & Symptoms of Hernia
Most hernias present as a swelling that do not require any immediate medical attention and is more obvious when standing, straining or during physical exertion. However, a hernia can cause discomfort or pain depending on the size of the hernia.
The three key aspects of hernia assessment are:
- Is it reducible (does it go back into the abdominal cavity)? An irreducible hernia is termed “incarcerated”.
- Is the hernia tender?
- Do the patient have symptoms of bowel obstruction?
If a hernia is associated with these symptoms, please seek immediate surgical input:
- Severe pain
- Hernia is irreducible and tender
- Nausea and/or vomiting
- Absence of flatus or bowel motion (obstipation)
The presence of pain implies there is inflammation associated with the hernia and the hernia is typically firm/irreducible. The next important assessment is of the content of the hernia. If the hernia is associated with obstipation, this implies there is bowel stuck in the hernia. This is a surgical emergency and may require emergency surgery.
Diagnosis
Diagnosing a hernia is usually a clinical judgement. The doctor should be able to see and/or palpate a swelling. In certain cases, imaging (such as an Ultrasound or CT, Computerized Tomography) may be required to define the anatomy of the hernia.
Type of Hernia
There are different types of hernias and are classified by their location. The majority of abdominal wall hernias are in the groin and inguinal hernia is the most common groin hernia.
Inguinal hernia
This is a groin hernia with protrusion of intra-abdominal contents through the inguinal canal. Inguinal hernias present as a groin swelling that disappears on lying down and are more prominent on standing or straining. Most inguinal hernias are asymptomatic and rarely cause pain. Most inguinal hernias are on one side only but some patients can develop an inguinal hernia on the opposite side. Inguinal hernias are more common in males as there is a natural weakness in the deep inguinal ring where the spermatic cord enter/exit the inguinal canal.
There are two types of inguinal hernia based on the relationship of the hernia to the inferior epigastric vessels:
Direct
Located medial to the vessels and the hernia comes out through a weakness in the posterior wall of the inguinal canal.
Indirect
Located lateral to the vessels and the hernia comes out through the deep inguinal ring. This is thought to be secondary to failure of closure of the embryonic processus vaginalis.
Femoral Hernia
This is a rare form of groin hernia and are more common in females. The hernia protrude medial to the femoral vessels and nerve, through the femoral canal. As the femoral canal is narrow, femoral hernia have a high risk of strangulation and surgery is recommended for all femoral hernia due to this increased risk.
Umbilical & Paraumbilical Hernia
Umbilical hernia is located in the umbilicus (“Bellybutton” hernia) and may be present at birth. The abdominal wall defect in the majority of cases will close spontaneously. If the umbilical hernia is present beyond five years old, they are unlikely to resolve and may require intervention. However, it is reasonable to monitor an umbilical hernia in a child as strangulation is uncommon.
“Paraumbilical” hernia are hernias that occur around the umbilicus. They present as a swelling in the umbilicus (“outie”) and do not resolve by itself. Surgery is recommended and imaging are generally not necessary prior to surgery.
Ventral Hernia
Most ventral hernia present with a small swelling and can be anywhere between the xiphoid process (lower end of sternum/breastbone) and the umbilicus. This type of hernia are also referred to as an “epigastric” hernia and is due to a weakness in the midline of the abdominal wall. If they are symptomatic, surgery is recommended. In certain cases, imaging may be required to define the anatomy of the hernia.
Incisional Hernia
This is a hernia from incomplete healing of a post-surgical abdominal wound and present as a swelling at or near the surgical incision.
There are various factors linked with an increased risk of developing an incisional hernia:
- Obesity
- Multiple abdominal operations (reduced strength of the abdominal wall musculature with each subsequent surgery)
- Poor nutrition and smoking
- Increased abdominal pressure post-operatively such as coughing or heavy lifting
- Post-operative wound infection
Imaging may be recommended to assess the size and location of the hernia as there may be more than one incisional hernia present. If they are asymptomatic, non-operative management is a reasonable approach. However, surgery is recommended for symptomatic incisional hernias and the extent of surgery is dependant on the complexity of the incisional hernia.
Spigelian Hernia
Spigelian hernia protrudes through the junction between linea semilunaris (lateral edge of rectus muscle) and the arcuate line (free inferior margin of the posterior rectus sheath). This hernia occurs in the lower half of the abdominal wall and generally have a small defect with a high risk of strangulation. Imaging is recommended to confirm the diagnosis.
Treatment Options
The treatment depends on the type and extent of the hernia. This will be discussed with you at your consultation with Dr. Michael Chu.
Potential Complications from Hernia
If a hernia is irreducible, this can lead to complications such as:
Strangulation
Pressure at the abdominal wall defect on the hernia content may compromise the blood supply to the content of the hernia. This may lead to ischemia and subsequently gangrene. This requires urgent surgery to reduce and repair the hernia.
Obstruction
If the hernia contains bowel and is irreducible, this leads to bowel obstruction. Patients present with crampy abdominal pain, vomiting and obstipation. This is life-threatening and is an emergency requiring immediate surgical repair.