Two-team lateral lymph node dissection assisted by the transanal approach for locally advanced lower rectal cancer: comparison with the conventional transabdominal approach

Background An optimal surgical approach to lateral lymph node dissection (LLND) remains controversial. With the recent popularity of transanal total mesorectal excision, a two-team procedure combining the transabdominal and transanal approaches was established as a novel approach to LLND. This study aimed to clarify the safety and feasibility of two-team LLND (2team-LLND) and compare its short-term outcomes with those of conventional transabdominal LLND (Conv-LLND). Methods Between April 2013 and March 2020, 463 patients diagnosed with primary locally advanced rectal cancer underwent a transanal total mesorectal excision; among them, 93 patients who underwent bilateral prophylactic LLND were included in this single-center, retrospective study. Among these patients, 50 and 43 patients underwent Conv-LLND (the Conv-LLND group) and 2team-LLND (the 2team-LLND group), respectively. The short-term outcomes, including the operation time, blood loss volume, number of complications, and number of harvested lymph nodes, were compared between the two groups. Results The intraoperative and postoperative complications in the 2team-LLND group were equivalent to those in the Conv-LLND group; furthermore, the incidence of postoperative urinary retention in the 2team-LLND group was acceptably low (9%). Compared with the Conv-LLND group, the 2team-LLND group had a significantly shorter operation time ( P = 0.003 ), lower median blood loss ( P = 0.02 ), and higher number of harvested lateral lymph nodes ( P = 0.0005 ). Conclusion The intraoperative and postoperative complications of 2team-LLND were comparable with those of Conv-LLND. Thus, 2team-LLND was safe and feasible for advanced lower rectal cancer. Moreover, it was superior to Conv-LLND in terms of the operation time, blood loss volume, and number of harvested lateral lymph nodes. Therefore, it can be a promising LLND approach.