To the Editors:

We read with interest the article by Liang, who reported technical feasibility of laparoscopic lateral pelvic lymph node dissection (LPLND) for lower rectal cancer after concurrent chemoradiation, citing data from our institution.1,2 Although the data as well as the attached video were excellent, one important aspect that deserves further comment is discussion regarding combined resection of the iliac vessels.

There are three important lateral pelvic regions highly involved by metastasis of lower rectal cancer: the obturator region, the internal iliac artery region, and the internal pudendal artery region.3 In particular, the internal pudendal artery region, which is the periphery of the internal iliac artery, is the most frequent site for metastasis that accounts for 56% of lateral pelvic metastasis.3 Consequently, as Liang discussed, combined resection of the iliac vessels is required to obtain sufficient surgical margin when nodal involvement exists grossly in this region.2,3 However, Liang concluded that combined resection of the iliac vessels was currently too difficult to perform laparoscopically.

We have recently reported 14 cases that underwent laparoscopic LPLND for lower rectal cancer after concurrent chemoradiation.4 Notably, 11 of the cases underwent combined resection of the iliac vessels in order to perform complete dissection of the internal pudendal artery region. All procedures were successfully performed without conversion to open surgery, and median blood loss and operation time were 25 ml and 413 minutes, respectively. Importantly, median number of retrieved lymph nodes was 23, which was much higher than Liang’s data. Consistent with Liang’s data, postoperative recovery was excellent with median flatus passage of one day. Autonomic nerve was carefully preserved in all cases, and consequently, there was no urinary dysfunction. According to these data, we would conclude that combined resection of the iliac vessels can be safely performed through laparoscopic approach.

Liang’s excellent data, as well as our data, clearly indicate that the laparoscopic approach brings much better short-term outcomes than the traditional open approach for LPLND. In the light of finding that LPLND for lower rectal cancer achieves 45–75% five-year-survival even in the presence of lateral pelvic metastasis, laparoscopic LPLND would be the next promising challenge that could not only provide survival benefit but also minimize bleeding and postoperative complications with enhanced visualization.2,3,5 With acceptance on this point, further recruitment of the patients is justified, and long-term follow-up is needed to clarify the oncological outcomes of this procedure.