Laparoscopic vs Open Surgery for Low Rectal Cancer—Reply

Abstract

COMMENT & RESPONSEIn Reply We appreciate the comments by Yuan et al regarding our recent Original Investigation. 1 During the surgical operation, we strictly followed the study design of at least 10 cm for proximal resection margin (PRM). The fact that one-fourth of patients in the laparoscopic group had a PRM of 9 cm or less most likely reflects the contraction of resected specimen from the time of resection to the time of measurement (typically at the end of surgery). A similar phenomenon (PRM at <10 cm in some patients) was also reported by the COREAN trial. 2 The shorter PRM in the laparoscopic group (12.4 cm vs 13.0 cm in the open group) has also been reported previously in the COLOR II trial (16.0 cm vs 19.0 cm). 3 We do not believe that the difference is clinically important despite the statistical difference but agree with Yuan et al that the likely effect on longterm oncologic outcomes is worthy of careful investigation.With regard to 9 or fewer dissected lymph nodes (LNs) in more than one-fourth of patients, 1 we generally agree with the speculation by Yuan et al. Indeed, subgroup analysis showed a higher number of dissected LNs in patients with stage I disease (15 and 14.5 in the laparoscopic and open groups, respectively) than in patients with stage II or III disease (12 in both groups). Such an unorthodox finding most likely reflects the use of preoperative chemoradiotherapy in patients with stage II or III disease. Indeed, greater than 95% of patients with stage II or III disease in the LASRE trial received preoperative chemoradiotherapy. With regard to learning curve of pathologists in recognizing LNs, we agree that it is possible, 4 but do not have evidence that either supports or argues against such a possibility.The indication of diverting ostomy in rectal cancer surgery is an ongoing issue of debate. We agree with Yuan et al that low anastomosis, malnutrition, male sex, neoadjuvant chemoradiotherapy, and intraoperative anastomotic failure are good candidates for diverting ostomy, 5 but the incidence of anastomotic leakage varies substantially across different studies, and certainly across surgeons with different levels of ex-pertise. At a pragmatic level, several well-established risk factors have been associated with anastomotic leakage, 6 though preoperative prediction of anastomotic failure could be difficult in clinical practice. Per comment by Yuan et al, we will review this issue in the forthcoming analysis of the oncologic outcomes of the LASRE trial.