title: 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).
  
  
  CONCLUSIONS
  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.
authors.affiliation: Academic Surgical Unit, Barts' Health NHS Trust, Queen Mary University London, Whitechapel, London, UK. alex007@doctors.org.uk
authors.forename: Alexander
authors.initials: A
authors.lastname: Hotouras
authors.forename: Jamie
authors.initials: J
authors.lastname: Murphy
authors.forename: Niall
authors.initials: N
authors.lastname: Power
authors.forename: Norman S
authors.initials: NS
authors.lastname: Williams
authors.forename: Christopher L
authors.initials: CL
authors.lastname: Chan
mesh_terms: D000368:Aged; D000369:Aged, 80 and over; D003110:Colonic Neoplasms / Q000601:surgery*; D003125:Colostomy / Q000009:adverse effects* / Q000379:methods; D005260:Female; D046449:Hernia, Abdominal / Q000000981:diagnostic imaging* / Q000209:etiology*; D006801:Humans; D015994:Incidence; D008297:Male; D008875:Middle Aged; D011183:Postoperative Complications; D011859:Radiography; D012189:Retrospective Studies