Objective: Removing rectal adenomas not only relieves symptoms, but also eradicates the incidence of carcinoma. There are many techniques for local removal of rectal polyps. Transanal endoscopic microsurgery (TEM) is the most recent. The purpose of this study is to present our long-term results using TEM for rectal adenomas, paying special attention to the risk factors of harboring a malignancy.
Methods: Data from all patients undergoing TEM from December 1995 to December 2005 were collected prospectively. The selection criteria were benign sessile adenomas below the peritoneal reflection. In the study period, 173 patients were operated on for an apparently benign rectal adenoma. The mean distance of lower tumor was 7.6 cm (range, 1-18 cm), and the mean distance to upper edge was 11 cm (2-20 cm). Full-thickness local excision was performed in all procedures. Patients were followed for a minimum of 1 year.
Results: According to the histologic findings, 14% of the specimens were invasive carcinomas. No statistical differences were found when comparing the histologic findings by tumor size, distance to the anal verge, or location.In 10 (5.8%) cases, the dissection was considered uncompleted because of a normal mucosa margin smaller than 1 mm. The mean hospital stay was 4 days (2-30 days). The morbidity rate was 14.5%. There was 1 postoperative death (0.6%). There were 9 (5.4%) histologically proven recurrences. Four of the patients with recurrence had uncompleted microscopic circumferential resection (P = 0.001). At a mean follow-up of 35 months (range, 12-82 months), all carcinoma patients were alive with no evidence of disease.
Conclusions: In conclusion, a significant number of adenomas that we assumed preoperatively to be benign were already carcinomas and we were unable to find any reliable predictor to identify them. TEM full-thickness excision provided a low rate of postoperative morbidity and potentially avoided a significant number of major abdominal operations and local recurrences.