Analgesic efficacy of preemptive local wound infiltration plus laparoscopic-assisted transversus abdominis plane block versus wound infiltration in patients undergoing laparoscopic colorectal resection: study protocol for a randomized, multicenter, single-blind, noninferiority trial

BACKGROUND: Transversus abdominis plane (TAP) block and wound infiltration (WI) are common locoregional anesthesia techniques for pain management in patients undergoing colorectal laparoscopic surgery. Comparative data between these two practices are conflicting, and a clear benefit of TAP block over WI is still debated. The main purpose of this study is to determine the efficacy in pain control of WI compared with WI plus laparoscopic TAP block (L-TAP) in cases of laparoscopic colorectal resection. Secondary aims are to evaluate other short-term results directly related to pain management: the need for rescue analgesic drugs, the incidence of postoperative nausea and vomiting, the resumption of gut functions, and the length of hospital stay. METHODS/DESIGN: This is a prospective, randomized, controlled, two-arm, multicenter, single-blind study evaluating the efficacy of postoperative analgesic management of WI versus WI plus L-TAP in the context of laparoscopic colorectal surgery. Randomization is at the patient level, and participants are randomized 1:1 to receive either WI alone or WI plus L-TAP. Those eligible for inclusion were patients undergoing laparoscopic resection for colorectal tumor or diverticular disease at the Division of General and Hepatobiliary Surgery, Verona University, Verona, Italy, and at the Colorectal Cancer Center, Kyungpook National University, Daegu, Korea. Fifty-four patients are needed in each group to evidence a difference greater than 1 of 10 according to the numeric rating scale for pain assessment to establish that this difference would matter in practice. DISCUSSION: The demonstration of a noninferiority of WI compared with WI plus L-TAP block would call into question TAP block usefulness in the setting of laparoscopic colorectal surgery. TRIAL REGISTRATION: ClinicalTrials.gov, NCT03376048. Prospectively registered on 15 December 2017. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (10.1186/s13063-019-3509-y) contains supplementary material, which is available to authorized users.