Objective: To investigate the clinical value of transanal endoscopic microsurgery (TEM) for rectal intraepithelial neoplasia (IN) and early rectal carcinoma.
Methods: Fifteen patients with rectal tumor were selected to undergo local excision by TEM. The pre-operative diagnosis by biopsy and endoanal ultrasonography (EUS): rectal low-grade IN in 8 cases, high-grade IN in 4 and early rectal carcinoma in 3. The average distance of tumors from the anal verge was 7.2(4-15) cm. The average tumor size was 1.8(1-4) cm. The average proportion of the circumference of bowel lumen involved was 20%(10%-40%).
Results: All the 15 rectal tumors were achieved complete excision (submucosal excision in 5, full-thickness excision in 10), and all the resection margins were clear. The average operating time was 57 (40-90) min. The average blood loss was 35 (10-60) ml. The average post-operative stay was 4.5 (2-9) d. The post-operative pathological diagnosis: rectal low-grade IN in 5 cases, high-grade IN in 6, early submucous invasive carcinoma (pT(1)) in 2, advanced carcinoma (pT(2)) in 2. The diagnostic accuracy of EUS in assessing invasive depth of rectal tumor was 86.7% (13/15). The average follow-up period of 15 patients was 6 (2-10) months. There was no local recurrence occurred.
Conclusion: TEM is an ideal minimally invasive procedure for the treatment of rectal IN and early rectal carcinoma, with excellent exposure and accurate excision, providing a high-quality tumor specimen for pathological staging. Pre-operative EUS is very important in selecting patients suitable for resection by TEM.