Between 87,000 and 135,000 intestinal stomas (ileostomy and colostomy) are created each year. Approximately half of these will be permanent stomas. 30-50% (20-35000) will then develop parastomal hernias which may require surgical
Parastomal Hernia Risks Factors
- Intra-abdominal pressure factors
Wound healing factors
- Genetics (collagen deficiency)
- Site outside of rectus sheath
- Stoma defect created too large
Symptoms of parastomal hernia
- Protrusion of stoma beyond abdominal wall
- Prolapse of stoma
- Enlargement of stoma
- Appliance leakage / poor fit
- Incarceration or strangulation
Stoma closure is the best option, but when it is not feasible, other approaches need to be considered. Primary suture repair has an unacceptably high recurrence rate. Stoma re-siting often results in 3 hernias with a hernia at the previous stoma site, one at the midline incision and one at the new stoma site. Mesh repair is now frequently been utilized.
Onlay mesh repair
This approach often allows for easy hernia reduction, but may be associated with difficult adhesiolysis and results in a large peri-wound cavity. Wound complications are a concern and post operative stoma care can be difficult for the patient. A midline approach to an onlay repair may be difficult in the obese patient and there may be devascularization due to creation of large tissue flaps.
This approach has been shown to have unacceptably high recurrence rates in the midline hernia literature and is unlikely to have better outcomes in this atypical ventral hernia.
This approach uses Laplace’s law and has been adopted in midline ventral hernia repair. Alterations have to be made to the basic technique to accomodate the stoma.
An underlay mesh is placed with the stoma exiting at the lateral border of the mesh. Overlap is achieved with the mesh lying on the distal few centimeters of the stoma.
A keyhole is made in the mesh and the stoma is brought through. The slit is dealt with in various ways including with usage of second piece of mesh in the double keyhole technique.
Standard technique for a laparoscopic incisional hernia repair is used with access away from incisions and the stoma, complete adhesiolysis, and sizing of the mesh to allow adequate overlap to healthy tissue. Mesh is prepared for either an underlay (“laparoscopic sugarbaker”) or keyhole placement. Transfacial sutures should be considered along side the stoma.
Case series with varying lenghts of followup demonstrate a 4-16% recurrence rate for the laparoscopic underlay vs 27-37% recurrence for the keyhole technique.
Parastomal Hernia Prevention
A number of case series have demonstrated that the use of polypropylene mesh at the time of stoma creation is associated with low hernia rates and low infection rates. Early results from a randomized study of the use of biologic mesh at the time of ileal conduit formation has shown a hernia rate of 6% in the mesh group and 30% in the non mesh group.
Parastomal hernias are common complications with various techniques available for repair. Hernia prevention with prophylactic mesh placement at the time of stoma creation may be the continued focus of future research.
Kristi Harold, M.D. Parastomal Hernia Repair – Best Techniques. Challenging Hernias Post-Graduate Course. April 15, 2010.