Radiological incidence of parastomal herniation in cancer patients with permanent colostomy: what is the ideal size of the surgical aperture?

Abstract

Background: Parastomal herniation frequently complicates stoma formation. Aperture size has been shown to be an independent predictor of hernia development but there is a paucity of data regarding the ideal stoma diameter. The aim of this study was to establish the radiological incidence of herniation in patients with a permanent colostomy and correlate it with the size of the abdominal wall defect in order to identify an aperture diameter associated with a reduced herniation risk.

Methods: All patients who underwent permanent colostomy formation for colorectal cancer over a five-year period in a single institution were recruited to the study. Patient demographics, operative details and stoma-related symptoms were recorded. Post-operative CT scans were reviewed for evidence of parastomal herniation. The diameter of the abdominal wall defect was measured radiologically.

Results: 43 patients (mean age 69 years) were included in the analysis. Radiologically, 25/43 (58%) had evidence of a parastomal hernia. The median aperture diameter was 35 mm (range 25-58 mm) in patients with a parastomal hernia and 22 mm (range 10-36 mm) in patients without herniation (p < 0.0001). There were no cases of herniation with an abdominal wall defect size <25 mm. The median follow up was 26.0 months (range 6-55) in patients with herniation as opposed to 16.0 months (range 7-36) in patients without herniation (p = 0.11).

Conclusion: The majority of patients with a permanent colostomy develop a parastomal hernia within the first two post-operative years. Parastomal herniation appears unlikely to develop with an abdominal wall defect diameter ≤25 mm provided this does not enlarge with time. Surgical techniques that utilise stapling devices to form a 'custom-made' and rigid trephine might reduce the herniation risk.