A parastomal hernia is a common complication following ostomy surgery, which creates an artificial opening, or stoma, on the abdomen to divert waste. The stoma can be an ileostomy, colostomy, or urostomy. This hernia occurs when tissue, typically a portion of the intestine or fatty tissue, pushes through the weakened abdominal wall near the stoma. The condition is prevalent, with estimates suggesting that up to 78% of people with a stoma may develop one over time.
Understanding the Condition
The abdominal wall supports the internal organs. Creating a stoma requires an intentional opening through the layers of muscle and fascia. This opening, known as the fascial defect, is a necessary weak point allowing the intestine to reach the skin’s surface. A parastomal hernia develops when abdominal contents protrude through this defect, expanding the space around the stoma.
The condition is characterized by a visible bulge near the stoma site. A parastomal hernia is anatomically distinct from an incisional hernia, as it specifically involves the tract created for the stoma. This allows a portion of the bowel or omentum to push outward. The abdominal contents, surrounded by a hernia sac, bulge out under the skin adjacent to the opening, often surrounding or pushing against the stoma itself.
Why Parastomal Hernias Develop
The primary cause of a parastomal hernia is the necessary weakening of the abdominal wall muscles when the stoma is created. The intestine must pass through the abdominal muscles, and the resulting fascial defect makes the area susceptible to protrusion. Anything that significantly increases pressure within the abdominal cavity can push internal contents through this weak point, leading to hernia formation.
Patient-related factors increase intra-abdominal pressure, including obesity, chronic coughing, heavy lifting, or chronic constipation. Advanced age is also a factor, as abdominal muscle strength naturally diminishes. Furthermore, conditions like malnutrition, diabetes, and the use of corticosteroids can impair wound healing and weaken connective tissues, making a hernia more likely.
Surgical factors also contribute to the risk. If the initial size of the fascial defect is too large, it offers less resistance to internal pressure. Stoma creation performed during emergency surgery, rather than a planned elective procedure, is associated with a higher risk. The specific technique used to route the stoma, such as whether it passes through the rectus abdominis muscle, can also influence hernia formation.
Recognizing the Indicators
The most common indicator of a parastomal hernia is a visible bulge or swelling around or underneath the stoma. This protrusion may be small initially and gradually increase in size. The bulge often becomes more noticeable when a person stands up, coughs, or exerts themselves, and it may flatten or reduce when lying down.
Secondary signs relate to the impact of the bulge on the stoma and surrounding area. Patients may experience discomfort, pressure, or localized pain. Difficulty applying or keeping the ostomy appliance securely in place is a significant indicator, often leading to frequent leakage and skin irritation. Changes in stoma function, such as alternating constipation and diarrhea, or symptoms like nausea and vomiting, can signal a severe complication like bowel obstruction.
Management and Treatment Options
Managing a parastomal hernia involves a spectrum of approaches, from conservative methods to complex surgical interventions. Most parastomal hernias are not immediately life-threatening and can be effectively managed without surgery. The decision to pursue surgical repair depends on the severity of symptoms, the impact on quality of life, and the presence of complications.
Conservative Management
Conservative management focuses on alleviating symptoms and preventing the hernia from worsening. Lifestyle modifications include weight management and avoiding activities that generate excessive intra-abdominal pressure, such as heavy lifting. Smoking cessation is also recommended, as chronic coughing increases strain.
Wearing specialized abdominal support garments or hernia belts can help contain the bulge and provide external compression. These systems improve comfort and help secure the ostomy appliance, reducing leakage and skin issues. While these non-operative strategies effectively manage symptoms, they do not address the underlying anatomical defect and cannot cure the hernia.
Surgical Repair
Surgical intervention is reserved for hernias causing severe pain, repeated obstruction, or those large enough to prevent proper function of the ostomy appliance. Repair techniques are categorized into local tissue repair and mesh reinforcement. Mesh reinforcement is the preferred strategy due to significantly lower recurrence rates. Simple local tissue repair, or primary closure, involves sewing the edges of the fascial defect together. However, this technique alone has a very high recurrence rate, sometimes reaching 76%.
Mesh reinforcement is the standard approach for repair, as the prosthetic material strengthens the abdominal wall. Mesh can be placed in various configurations:
- An onlay (on top of the fascia)
- A sublay (under the muscle layers)
- Using specific techniques like the Sugarbaker or keyhole approach
The Sugarbaker technique involves routing the intestine against the abdominal wall and covering it with a large piece of mesh, demonstrating lower recurrence rates compared to the keyhole technique.
Another option is to relocate the stoma to a new, healthy site on the abdominal wall, potentially combined with mesh repair at both the new stoma and the original hernia site. Stoma relocation is a complex operation with the risk of a new hernia forming at the new site. Despite surgical advancements, repair remains challenging. Overall recurrence rates range widely (13.5% to over 35%) depending on the technique and follow-up time, with a complication rate of about 26%.