Endoscopic posterior mesorectal resection after transanal local excision of T1 carcinomas of the lower third of the rectum

PURPOSE: The rectum-sparing transanal local excision is a well-established treatment of T1 carcinomas of the lower third of the rectum. A potentially increased locoregional recurrence rate by this procedure is tolerated because of the high morbidity and mortality risk of transabdominal rectal resection. Dorsoposterior extraperitoneal pelviscopy makes it possible to remove the relevant lymphatic drainage of the lower third of the rectum minimally invasively, in the sense of a rectum-sparing endoscopic posterior mesorectal resection. It has to be considered whether endoscopic posterior mesorectal resection in combination with transanal local excision allows for local radicality and an adequate tumor staging in T1 carcinomas of the lower third of the rectum, in terms of better-directed therapy planning compared with transanal local excision alone. METHODS: We operated on 11 consecutive patients with T1 carcinomas of the lower third of the rectum by transanal local excision in combination with endoscopic posterior mesorectal resection as a two-stage procedure in the period from 1998 to 2005. RESULTS: It was possible to perform a complete excision of the primary and to resect the posterior part of the mesorectum in all cases. Postoperative morbidity consisted of two transient neurologic complications and a pulmonary embolism. There was no mortality. Histologic analysis revealed a median of eight (range, 4-20) lymph nodes. Two patients diagnosed with lymph-node metastases received adjuvant radiochemotherapy. After a median follow-up of 48 (range, 4-60) months, there was noevidence for locoregional recurrence. In one patient liver metastasis was detected eight months postoperatively. CONCLUSIONS: Radical excision of the primary tumor and an adequate tumor staging in T1 carcinomas of the lower third of the rectum seems to be achievable by means of transanal local excision and endoscopic posterior mesorectal resection.