Transanal endoscopic microsurgery.

Traditional methods of excising adenomas and selected carcinomas of the distal rectum provide adequate exposure and acceptable cure rates. Recurrence rates after locally excising adenomas, however, are 12% to 25%, possibly because the limited exposure has led to less than adequate resection margins. Whether or not TEM can yield lower recurrence rates remains to be seen, but this perhaps is not the main reason one should include TEM in his or her armamentarium. Rather, it is the improved exposure, the superior optics, and the opportunity to address lesions in the upper rectum that set TEM apart from conventional instrumentation. One should also keep in mind that these "inaccessible" lesions have been treated heretofore with either a transsacral or transabdominal approach, both of which are accompanied by a lengthy hospital stay and potential morbidity. When considering TEM excision of rectal cancers, proper patient selection cannot be overemphasized. Endorectal ultrasonography can help to determine depth of penetration preoperatively, and TEM can be used with curative intent for those lesions with minimal involvement of the rectal wall. TEM can also be used as a means to palliate the primary tumor of those patients with incurable, disseminated disease. Minimal-access surgery is here to stay. TEM may gain acceptance in this arena, marking a new technology for the treatment of a number of rectal conditions. The considerable skill necessary to perform this operation, combined with the relatively infrequent nature of the pathology addressed, however, will make TEM the domain of only a few surgeons.