A parastomal hernia is a common complication following ostomy surgery, which creates an opening (stoma) on the abdomen to divert waste. A hernia occurs when an internal organ or fatty tissue pushes through a weakness in the surrounding muscle or tissue wall. Estimates suggest that up to 78% of ostomy patients may develop a parastomal hernia, often within the first two years after surgery. The surgical creation of the stoma introduces a permanent area of weakness in the supportive abdominal muscle layers.
Defining Parastomal Hernias
A parastomal hernia is the protrusion of abdominal contents, such as a loop of the small intestine, colon, or fatty tissue, through the abdominal wall defect created for the stoma. This protrusion occurs immediately adjacent to the stoma site. The abdominal wall is composed of layers of muscle and fascia that normally contain the internal organs.
To create a stoma, a surgeon must make an opening through the abdominal muscles, particularly the rectus abdominis. This necessary opening creates a discontinuity in the fascia and muscle layers, leading to a vulnerable site. Internal pressure within the abdomen then acts on this weakened area, causing the contents to bulge out next to the stoma. The hernia sac can contain the loop of bowel forming the stoma, or a separate loop of intestine or omentum that has pushed through the fascial opening.
Factors Contributing to Development
The development of a parastomal hernia is influenced by patient-specific and surgical factors. Any condition that increases pressure inside the abdomen places greater stress on the weakened stoma site. Advanced age contributes because muscle strength and connective tissue integrity naturally diminish over time, offering less support.
Obesity, particularly a high waist circumference, raises the risk significantly, as excess abdominal fat increases intra-abdominal pressure. Chronic conditions that lead to persistent straining, such as chronic coughing or constipation, also place strain on the abdominal wall. Poor nutritional status, diabetes, and the use of corticosteroids impair the body’s ability to heal and maintain strong tissues, increasing the risk of hernia formation.
Surgical technique plays a substantial role in the likelihood of development. A large fascial opening increases the risk, with an aperture size greater than three centimeters being a significant predictor of hernia formation. If the stoma is not placed correctly to pass directly through the rectus abdominis muscle, which provides natural support, the area is more prone to herniation. Emergency ostomy surgery, which may not allow for optimal preoperative planning, is another factor associated with increased risk.
Recognizing the Signs
The most common sign of a parastomal hernia is a visible bulge or swelling that develops around or underneath the stoma. This bulge may be small and only noticeable when coughing or straining, or it can be large and constant, increasing in size over time. Patients often report a sensation of heaviness, dragging, or pressure in the area, though the hernia itself is not always painful.
Functional issues related to the ostomy appliance are a frequent presentation. The changing abdominal contour caused by the bulge makes it difficult to achieve a secure seal for the stoma bag, leading to frequent leakage and skin irritation. A poorly fitting appliance can result in peristomal skin breakdown and odor. During a physical examination, a doctor can often diagnose the hernia by palpating the area while the patient is standing or coughing. Imaging tests like a CT scan or ultrasound may be used to confirm the diagnosis, classify the hernia, and check for potential complications like bowel obstruction.
Management and Treatment Options
Treatment for a parastomal hernia depends on the severity of symptoms and the presence of complications. Small hernias causing minimal discomfort are managed conservatively without surgery. Non-surgical management focuses on reducing abdominal pressure and providing external support.
Wearing a specialized hernia support belt or abdominal binder helps contain the bulge, provide comfort, and improve the seal of the ostomy appliance. Lifestyle modifications are recommended, including weight management to reduce intra-abdominal pressure and avoiding heavy lifting or strenuous activities that cause straining. A stoma care nurse can assist with adjusting the pouching system to accommodate the new abdominal contour, often resolving issues like leakage and skin irritation.
Surgical repair is reserved for hernias causing chronic pain, persistent appliance issues, or those presenting with serious complications. Indications for elective surgery include bowel obstruction, or when the hernia becomes incarcerated or strangulated. Strangulation is a life-threatening emergency requiring immediate intervention. The high recurrence rate influences the choice of surgical technique.
The three primary surgical approaches are local tissue repair, stoma relocation, and mesh repair. Simple primary repair, which involves sewing the fascial defect closed, has a very high recurrence rate and is largely avoided in elective settings. Stoma relocation involves closing the existing stoma and creating a new one elsewhere, but a new hernia can form at the new site. The most common and effective technique for repair is the use of surgical mesh to reinforce the abdominal wall defect.
Mesh repair, often performed laparoscopically using techniques like the modified Sugarbaker method, involves placing a mesh to cover the defect. This significantly lowers the risk of recurrence. The Sugarbaker technique lateralizes the bowel so it exits through a tunnel created by the mesh, providing a strong barrier against re-herniation. Surgeons may use synthetic or biological mesh, depending on the patient’s overall health and the complexity of the hernia.