Polyp Surveillance – Experience of a Single Gastrointestinal Endoscopy Unit

Background: International guidelines have recommended increasing the intervals for surveillance colonoscopy in patients with a history of colorectal polyps. The American Gastroenterological Association guidelines published in February 2003 suggest 5 yearly colonoscopy for patients with small tubular adenomas.

Aim: To assess the polyp yield from surveillance colonoscopy in a cohort of patients with a history of colorectal polyps.

Methods: From the endoscopy database we identified all patients with a history of colorectal polyps who underwent surveillance colonoscopy over a 30-month period (January 2001– September 2003), Surveillance was performed at intervals ranging from 6 months to 3 years reflecting clinical practice. Patients with subsequent polyps were identified and polyps were classified according to histology.

Results: In total 412 patients underwent surveillance colonoscopy during this period. Polyps were detected in 229/ 412 (56%) patients.

Histology was adenomatous in 126 patients (55%) with foci of invasive adenocarcinoma in 2 patients(%).

Hyperplastic polyps were found in 76 patients (33%).

Other benign pathology was documented in 28 patients (12%).

Conclusions: The polyp recurrence rate at surveillance was higher than anticipated. This may reflect an initial high miss-rate at the index colonoscopy, or may imply a significant cohort of higher-risk individuals. Malignancy was seen in two large polyps and both of these patients underwent curative colonic resection.

These results would appear to be at variance with international experience.