Outcomes of novel transanal operation for selected tumors in the rectum

Transanal endoscopic microsurgery facilitates access to proximal tumors in the rectum, but there is limited possibility for tumors above the peritoneal reflection because of high cost, training, and long operative time. The objectives of this study are to delineate the results achieved by novel transanal local excision (minimally invasive transanal surgery [MITAS]) with the use of a new anal retractor, stapler device, and several modified surgical techniques for selected rectal tumors.

Ninety-one patients with 93 tumors undergoing MITAS between 1993 and 2000 were retrospectively reviewed for prospectively collected data with a minimum 2 years followup and without adjuvant radiation or chemotherapy.

MITAS was accomplished in a median of 20 minutes with negligible blood loss, no mortality, and low morbidity for tumors locating 9 cm (range 5 to 20 cm) from the anal verge and measuring 25 mm (range 8 to 83 mm) of maximum diameter. No recurrent disease was observed in patients with 32 adenomas, 37 Tis, 5 low-risk pT1, and 14 high-risk pT1 carcinomas. Eight underwent additional operation, two patients with high-risk pT1 tumors who refused additional operations had recurrent disease, and the sole patient with surgical margin positive underwent a reexcision with MITAS for recurrence without further disease during a median of 63 months followup.

MITAS is a feasible transanal local excision procedure that allows access to proximal rectal tumors and "total excisional biopsy" with short operative time, negligible blood loss, and low morbidity for carefully selected adenomas and early carcinomas.