A parastomal hernia is a common complication following ostomy surgery. It involves the protrusion of abdominal contents, typically a section of the intestine or fatty tissue, through the weakened abdominal wall surrounding the surgically created stoma. The stoma is an opening made to allow waste to pass outside the body, but the incision creates a weak point in the muscle layers. Because of this inherent weakness, parastomal hernias are frequent, affecting 30% to over 70% of ostomy patients within a few years of the initial operation. While some hernias cause only minor issues, others lead to significant discomfort and management challenges.
Mechanism of Formation and Contributing Factors
The formation of a parastomal hernia starts with the surgical creation of the stoma, which requires making a hole through the abdominal muscle and fascia layers. This opening creates a defect in the abdominal wall’s integrity, which is constantly subjected to pressure from within the abdomen. Chronic intra-abdominal pressure eventually pushes tissue through this opening, resulting in the characteristic bulge. The size of the surgical opening is a factor, as an aperture larger than three centimeters increases the risk of hernia formation.
Patient-Related Risk Factors
Patient factors increase the likelihood of hernia formation. Advanced age is a risk factor, as muscle strength naturally diminishes over time. Obesity, defined as a BMI over 25 kg/m², significantly elevates intra-abdominal pressure. Conditions causing chronic straining, such as Chronic Obstructive Pulmonary Disease (COPD) or a persistent cough, also contribute by repeatedly increasing pressure on the weakened stoma site.
Surgical Risk Factors
Surgical technique also influences the risk. The type of ostomy performed matters, with end colostomies generally carrying a higher risk compared to ileostomies. If the stoma does not pass directly through the central rectus abdominis muscle, the abdominal wall may be less stable. Poor wound healing due to smoking, poor nutrition, or infection at the surgical site can compromise the strength of the tissue surrounding the stoma.
Identifying the Physical Signs
The most noticeable sign of a parastomal hernia is a visible bulge or swelling that develops around or beneath the stoma. This protrusion often becomes more pronounced when standing, coughing, or straining, as these actions temporarily increase abdominal pressure. The stoma itself may appear to change size or shape. Many people also experience discomfort, often described as an ache or a dragging sensation around the stoma site, particularly during physical activity.
A significant consequence of the hernia is difficulty with ostomy appliance management. The altered contour of the abdomen makes it challenging to achieve a secure seal for the pouch. This often leads to frequent leaks, skin irritation, and the need for specialized equipment.
Emergency Complications
It is important to recognize signs that indicate a potentially dangerous complication, such as incarceration or strangulation. Incarceration occurs when the protruding bowel tissue becomes trapped and cannot be gently pushed back into the abdomen. Strangulation is a medical emergency where the blood supply to the trapped tissue is cut off, causing tissue death. Symptoms requiring immediate medical attention include sudden, severe pain, fever, redness in the area, nausea, vomiting, or difficulty passing stool or gas.
Options for Treatment
Treatment depends heavily on the hernia’s size and whether it is causing symptoms or complications. For small, asymptomatic hernias, or for patients with significant health issues, a conservative, non-surgical approach is often recommended. This strategy focuses on supporting the abdominal wall and managing symptoms.
Conservative management frequently involves the use of specialized support garments, such as abdominal binders or hernia support belts. These compression garments provide external support to the area, which helps alleviate discomfort and improves the security of the ostomy appliance. Finding a modified pouching system with an ostomy nurse can also resolve issues like leakage and skin irritation caused by the uneven abdominal surface.
If the hernia is symptomatic, causing chronic pain, persistent appliance leakage, or presenting an acute complication, surgical repair becomes necessary. Surgical options include simply sewing the muscle closed, relocating the stoma to a new site, or using surgical mesh to reinforce the weakened area. Mesh repair is the most common and effective technique, as it significantly lowers the recurrence rate associated with simple tissue repair. Surgeons must carefully select the appropriate technique and material for each patient.
Lifestyle Management and Prevention
Patients can take several proactive steps to minimize the risk of developing a parastomal hernia or prevent its recurrence after repair. Maintaining a healthy weight is important, as excess abdominal weight increases the internal pressure that stresses the stoma site.
Strengthening the core muscles helps stabilize the abdomen, but this must be done carefully to avoid strain. Specific exercises, such as gentle pelvic tilts, are recommended to build muscle strength without increasing intra-abdominal pressure too quickly. Patients should adopt proper lifting mechanics, avoiding heavy lifting or strenuous activities that require bearing down, especially in the first few months after surgery.
Consistent use of a supportive garment, such as a binder or support belt, provides external reinforcement to the stoma area, particularly during physical activity or lifting tasks. Quitting smoking is also a beneficial step, as it improves tissue healing and eliminates the chronic coughing that places forceful strain on the abdominal muscles.