Examination of nodal metastases by a clearing method supports pelvic plexus preservation in rectal cancer surgery

PURPOSE: In rectal cancer surgery preservation of urinary and sexual functi on is attempted by means of operations preserving the autonomic nerves of t he pelvic plexus. Emergence of residual cancer because of a more shallow pl ane of dissection is a problem of concern with these methods, so we examine d indications for pelvic plexus preservation. METHODS: We studied 198 patie nts with rectal carcinoma who underwent abdominopelvic lymphadenectomy. Lym ph nodes along the superior hemorrhoidal artery and middle hemorrhoidal art ery medial to the pelvic plexus were defined as perirectal nodes, and nodes along the middle hemorrhoidal artery lateral to the pelvic plexus and alon g the internal iliac artery represented lateral intermediate nodes. Node me tastases were examined by the clearing method. RESULTS: Metastasis to perir ectal nodes occurred in 12.5 percent in patients with pT1 tumors, 28.3 perc ent-of those with pT2 tumors, and 50.0 percent of those with rectosigmoid j unctional cancer. Metastasis to lateral intermediate nodes was absent in pa tients with pT1 or pT2 tumors and was as low as 2.5 percent in patients wit h rectosigmoid junctional cancer. CONCLUSIONS: In patients with T1, T2, and rectosigmoid junctional cancer, perirectal, node dissection is necessary, but chances of residual cancer should remain minimal when the pelvic plexus is preserved.