Surgical excision of large rectal villous adenomas.

Large villous tumors occur most frequently in the rectosigmoid and have a significant incidence of harboring a malignancy. The presence or absence of malignancy may be determined only by complete excision. Presence of invasive carcinoma on pathologic examination requires surgical intervention appropriate for that diagnosis. Recurrence depends on the technique used for tumor removal. It is highest for fulguration and local excision and lowest for operations that excise all or part of the rectum. Because most recurrences can be managed with local measures and the risk of malignancy in recurrences is relatively low, the procedure with which the tumor can be completely excised with the least morbidity should be used. Local excision with or without mucosal closure should be used as first-line surgical therapy whenever possible. It should be possible to manage most tumors in the mid and low rectum with this technique. For larger tumors and those tumors more proximal, it may be necessary to use snare cautery in combination with local excision or fulguration. Alternately, for some proximal rectal lesions the two-scope technique mentioned earlier may allow local excision. For circumferential or near circumferential tumors in the low to mid rectum, circumferential mucosectomy should be used. It has been used successfully for tumors involving the entire rectum down to the dentate line. Although this technique has a low recurrence rate, the rate of incontinence associated with it precludes its use in smaller tumors that are amenable to local excision. Transanal endoscopic microsurgery described by Beuss et al can produce good results. The authors have no experience with this technique. However, because of its expense, the need for specialized training, and the infrequency with which other transanal techniques are insufficient, we fail to see a significant role for its use. If use of this technique becomes more widespread, additional data regarding its value will become available. Posterior approaches offer no advantage for removal of tumors that can be excised by transanal techniques. Most tumors that require partial or complete rectal excision should be amenable to anterior or low anterior resection. Low anterior resection is a less morbid procedure with which most surgeons have a fairly extensive experience. For extremely large tumors that extend to the dentate line, coloanal anastomosis is appropriate. The functional results are acceptable compared with the alternative of abdominoperineal resection. Abdominoperineal resection should be reserved for those patients with a diagnosis of invasive carcinoma in whom a lesser procedure would not constitute adequate treatment.