Purpose Deep neuromuscular blockade (NMB) can improve surgical conditions and possibly pain after lowrisk laparoscopic surgery. We hypothesized that targeting a deep level of NMB by a continuous compared with an on-demand infusion of rocuronium could improve surgical conditions in patients undergoing thoraco-laparoscopic esophagectomy. Methods In this single-centre, randomized-controlled, double-blind trial, patients received either a continuous infusion of rocuronium 0.6 mgÁkg-1 Áhr-1 (intervention) or NaCl 0.9% (control). Both surgeon and anesthesiologist were blinded to group assignment and the train-of-four measurements. Open-label rocuronium was given if requested (i.e., on-demand) by the surgeon. At the end of surgery, sugammadex was given if necessary to reverse the NMB. The primary outcome was the quality of surgical conditions during the abdominal phase of the operation as measured by the surgical rating scale (SRS). Secondary outcomes included the thoracic SRS, number of on-demand boluses, intraoperative surgical events, pain scores (up to 12 hr postoperatively), and duration of surgery. Results The median [interquartile range] abdominal SRS was not different between the intervention (4 [4-5]) and control (4 [4-5]) groups (median difference, 0; 95% confidence interval, 0 to 0; P = 0.45). The thoracic SRS was 4 [4-4] in both groups (P = 0.23). The median number of rocuronium bolus requests was higher in the control group compared with the intervention group (3 [3-6] vs 1 [0-2], respectively; P \ 0.01). There were no between-group Electronic supplementary material The online version of this article (