Current status of autonomic nerve-preserving surgery for mid and lower rectal cancers: Japanese experience with lateral node dissection.

Surgical practices for treatment of rectal cancer in Japan have changed from extended dissection along perivascular or parietal plane to pelvic autonomic nerve-preserving procedures without compromising radicality of surgical resection. Previous surgical results suggested the significant advantages of extended surgery in survival and local recurrence rate of Dukes B and C patients. More than 15 percent of patients with cancer in the lower rectum have extramesorectal spread to lateral pelvic nodes that can be removed by lateral dissection for local control and cure. Initially the total nerve-preserving procedure has been introduced for a complete preservation of para-aortic and intrapelvic nervous system in patients with early-stage cancer not requiring para-aortic and lateral lymph-node dissection. However, the concept of aggressive surgery for advanced rectal cancer has led to various types of pelvic autonomic nerve-preserving procedures, in which extended lymph-node dissection plus nerve-preserving technique with resection of one or more autonomic nervous segments has been performed. During two decades, total pelvic autonomic nerve-preserving procedure with lateral lymph-node dissection has been used increasingly for Dukes C lesion without increased local recurrence. The overall status of pelvic autonomic nerve-preserving procedures according to clinical experiences in Japan is reviewed in the context of cadaveric anatomic findings, Japanese vs. Western techniques and concepts, and our own clinical data.