Sessile adenomas are predominantly localized in the rectum and lower sigma. Surgical removal is indicated but often implies an invasive surgical procedure. Using conventional transanal surgical techniques, only the lower rectum can be reached and there are high rates of recurrence. The new technique combines an endoscopic view of the rectum under gas insufflation via a stereoscopic telescope with conventional surgical preparation and suturing. Adenomas can be excised using the mucosectomy technique or full-thickness-excision, whereas carcinomas should be excised using full-thickness excision with a sufficient border of healthy mucosa. In carcinomas of the sacral cavity, we remove the retrorectal fat up to the fascia of Waldeyer, including the regional lymph nodes. Transanal endoscopic microsurgery is the most economical and tissue-saving surgical technique for the removal of rectal adenomas and early rectal carcinomas.

Using the "transanal endoscopic microsurgery" technique, 140 patients were treated at the Department of Surgery in Cologne and Mainz. Of the patients with adenomas, 68.2% had typical symptoms preoperatively. The postoperative hospital attendance was 8.7 days, with an average resection size of 14.4 cm2. The postoperative complication rate was 5%, and there were no deaths related to the technique. In a prospective controlled trial, 2.2% of the patients with adenomas treated endoscopically in Mainz showed recidivation, requiring reoperation. The follow-up rate was 100%. In 30 cases, microscopic examination revealed carcinoma. Radical reoperation in 8 pT1 tumours showed neither remaining tumour nor lymph node metastases. Twelve patients with pT1 carcinoma treated by local surgery alone were recurrence-free with an average follow-up period of 12.3 months. So far, there have been no late results.