Background and aims: We evaluated the incidence of dysplasia in the mucosectomy area using resected specimens to determine preoperative risk factors for the occurrence of dysplasia in this area.
Patients and methods: We prospectively studied a consecutive series of 137 patients, each of whom underwent a restorative proctocolectomy with a mucosectomy and hand-sewn ileal J-pouch anal anastomosis between January 2003 and December 2004. Sections from the anal transitional zone mucosa were taken from the dentate line to 2.5 cm above the resected line and stained with hematoxylin and eosin then characterized as indefinite for dysplasia, low-grade dysplasia, and high-grade dysplasia based on the criteria of an international working group for rectal mucosal atypia.
Results: Dysplasia of the mucosectomy area was present in six (4.4%) of the patients, including one with low-grade and five with high-grade dysplasia. A multivariate analysis showed relations between age at time of surgery (>or=40 years) and duration of disease (>or=10 years) with a risk for development of mucosectomy area dysplasia.
Conclusion: The incidence of dysplasia of the mucosectomy area was 4.4%, and preoperative risk factors were shown to be duration of disease and age at time of surgery.