What is parastomal hernia

Parastomal hernia is the protrusion of content (Intestine, Omentum, Fat) of the abdominal cavity through a defect ( weakness) in the abdominal wall adjacent to a Stoma. The defect usually creates at the time of the initial surgery for the creation of the stoma. This is contributed by weak abdominal wall muscles. This manifests as a palpable defect or as a lump that increases in size during coughing or straining.

Incidence of parastomal hernia

Parastomal hernias are extremely common. Even with the perfect surgical technique, patients can develop parastomal hernias without any warning. Scientific studies have shown an incidence rate of up to 48% of all patients having stomas.

What contributes to parastomal hernias

• Type of stoma
  Patients with Colostomies have a higher chance of getting parastomal hernias compared to ileostomies. And end stomas get more hernias compared to loop stomas. End colostomies have the highest risk for parastomal hernias, and Loop ileostomies have the lowest risk.
  
• Surgical technique
  Trephine Stomas and stomas created laparoscopically have a lower risk for parastomal hernias.
  
• Advanced aged
  Elderly patients have a higher risk compared to young, fit individuals
  
• Other Risk factors
  Technical failure, obesity, malnutrition, post-operative wound infections, emphysema, cancer, smoking, constipation

Complications of parastomal hernia

Most Parastomal hernias remain asymptomatic. However, researches have shown complication rates varying from 11-70 percent’s.commen complications includes
Bowel obstruction (blockage of the small or large bowel)
Incarceration (Content which is comping out through the hernia defect remain outside due to adhesions.
Prolapse – sometimes, hernia leads to stoma prolapse
Pain and discomfort
Appliance leakage – this one of the commonest problems caused by parastomal hernias. Due to the bulge of the hernia, patients cannot fix the stoma bag properly, leading to leakage.

Types of Parastomal hernias

Different classification systems exist for parastomal hernias. Devlin Classified them into four groups.
Type 1 – Interstitial hernia
Type 2- Subcutaneous hernia
Type 3 – Intrastomal Hernia
Type 4 – peristomal hernia

Treatment of Parastomal hernia

If asymptomatic, parastomal hernias can be managed conservatively. Symptomatic parastomal hernias warrant active treatment.

The treatment method depends on whether it is a permanent stoma or not. Temporarily stoma, which has already served its function, can be reversed with hernia repair, which gives a permanent solution.

Permanent stomas are treated with Either stoma repair or stoma relocation. But stoma relocation gives a less satisfactory result as it can complicate the situation by further weakening the abdominal muscles.

Surgical techniques for Parastomal hernia repair.

These may be repaired by open surgical method or laparoscopically. One of the following surgical techniques can be used.

• Sugar baker

• Keyhole

• Sandwich mesh
• Fascial repair.

How to prevent Parastomal hernia

Usage of prophylactic mesh has been shown to reduce parastomal hernia formation.