ROCSS is a randomised controlled trial of the placement of a biological mesh at the site of stoma closure. Our hypothesis is that reinforcing the stoma closure site with a collagen mesh (Strattice®) is superior to the standard technique in preventing herniation at 2 years.

Closure of complex and contaminated abdominal wounds is challenging and carries risks, including wound dehiscence and incisional hernias. Use of biological meshes in these situations may provide a safe method of reducing these complications, especially long-term incisional hernias. ROCSS will use stoma site closure as a model for biological mesh placement during any difficult contaminated abdominal wall closures.

Hernia at the site of stoma closure occurs in up to 30% of patients and is associated with adverse effects on quality of life. In up to 10% of cases, patients are submitted to complex re-operation which carries significant morbidity. Not all patients will report symptoms or undergo repair, as they do not wish to have a further major operation. Incisional hernias at the site of stomas closure form an important and well defined subgroup. If there is a measurable benefit from mesh insertion, elective use of a collagen mesh would warrant consideration in the closure of other difficult, contaminated abdominal wounds. This study will also provide useful information on the value of using a CT scan as an early diagnostic tool of herniation, which could then be used in future abdominal wall studies as a surrogate endpoint for clinical hernia.

ROCSS aims to assess whether a biological mesh (collagen tissue matrix) reduces the incidence of clinically detectable stoma closure site hernias at two years compared to standard closure techniques. The primary outcome is Occurrence of clinically detectable hernias at two years post randomisation. Other outcomes include surgical re-intervention rate, surgical complications at 30 days post-operation and 1 year post-randomisation, quality of life and post-operative pain, cost-benefit analysis and radiological hernia rate at one year post-randomisation (an exploratory analysis will compare radiological hernia rate at 1 year with clinical hernia rate at 2 years to assess the value of using a CT scan as an early diagnostic tool of incisional hernias).

Randomisation is 1:1 between Strattice® mesh vs. standard closure. The sample size for the trial is 560 (80% power, 10% dropout/crossover, 40% proportional reduction - 25% to 15%) and recruitment will be over 2 years from at least 30 centres. ROCSS will be a double blind (observer blind) randomised controlled trial with a CT scan at one year and clinical follow up at 2 years. Cost benefit analysis and quality of life analysis will be performed at 2 years. The sample size will be reviewed prior to reaching target and may be increased 790 (90% power, 20% dropout/crossover, 40% proportional reduction - 25% to 15%).

Inclusion Criteria:

• Require an elective closure of an ileostomy or a colostomy.
• Able and willing to provide written informed consent.
• Aged 18 years or over.

Exclusion Criteria:

• Taking part in another clinical study which is related to the surgical procedure.
• Allergic to any porcine or collagen products.
• History of familial adenomatous polyposis, due to increased risk of desmoid tumours.
• The surgeon determines that a mesh repair will definitely be required e.g. due to large parastomal hernia.
• Unable or unwilling to provide written informed consent.