Two-Team Lateral Pelvic Lymph Node Dissection Assisted By the Transanal Approach

Although lateral pelvic lymph node dissection is considered as a treatment option for advanced rectal cancer, it is technically demanding. Recently, the transanal approach for total mesorectal excision has become increasingly used. In this Technical Note, we describe lateral pelvic lymph node dissection using a 2-team method that was assisted by the transanal approach.

First, the lateral pelvic area was entered from the anal side by dissection between the S4 sacral splanchnic nerve and levator ani muscle. Then, the fatty tissues including the obturator compartment and the distal part of the internal iliac compartment were separated from the inferior and superior vesical vessels and the bladder wall. Next, the fatty tissues were separated from the lateral pelvic wall. The obturator nerve was isolated and preserved, whereas the obturator vessels were resected at their peripheral end. Then, the fatty tissues were dissected from the bottom plane. Finally, the fatty tissues were dissected from the ventral bladder wall and were completely isolated from the obturator nerve in cooperation with the transabdominal team.

The 2-team method shortened the operative time dramatically and decreased mental and physical burden on the operators during lateral dissection. Assistance with the transanal approach helped with a secure and effective dissection, especially of the most distal parts, such as around the internal pudendal and inferior vesical arteries, because substantial skill is required for the transabdominal approach alone.

This procedure is useful for the safe and effective performance of lateral pelvic lymph node dissection for patients with rectal cancer.