Perioperative Subcutaneous Methylnaltrexone Does Not Enhance Gastrointestinal Recovery after Posterior Short-Segment Spinal Arthrodesis Surgery: A Randomized Controlled Trial.

Abstract

BACKGROUND CONTEXT\nPostoperative ileus is a major barrier to gastrointestinal recovery following surgery. Opioid analgesics likely play an important causative role, particularly in spinal or orthopedic surgeries not involving bowel manipulation. Methylnaltrexone, a peripherally-acting µ-opioid receptor antagonist, is a potential prophylactic treatment.\n\n\nPURPOSE\nTo assess the influence of perioperative subcutaneous methylnaltrexone administration on gastrointestinal recovery following short-segment lumbar arthrodesis surgeries.\n\n\nDESIGN\nThis is a randomized, double-blind, controlled trial.\n\n\nPATIENT SAMPLE\nEligible patients undergoing posterior short-segment lumbar arthrodesis surgeries at a single institution between February 2019 and April 2021 were enrolled in this study.\n\n\nOUTCOME MEASURES\nThe primary outcome measure was time-to-first bowel movement. Secondary outcome measures included time-to-discharge/discharge eligibility. Exploratory outcome measures included daily postoperative opioid consumption and pain scores.\n\n\nMETHODS\nIn this study, eligible patients were enrolled to receive either methylnaltrexone or placebo perioperatively. Time-to-bowel movement, time-to-discharge/discharge eligibility, intra- and postoperative analgesic administration, and pain scores were recorded and compared.\n\n\nRESULTS\n82 patients in total were enrolled; 41 to the methylnaltrexone and 41 to the placebo group. Both groups were similar in their baseline characteristics. There was no difference in median (range) time-to-bowel movement between the two groups [61.8 hours (35.7-93.6) versus 50.7 hours (17.8-110.8), p\u202f=\u202f0.391]. There was also no difference in time-to-discharge/discharge eligibility [105.0 hours (81.0-201.3) versus 90.7 (77.5-184.5), p\u202f=\u202f0.784]. Finally, there were no differences in either postoperative opioid consumption or numeric rating scores for back, leg, or abdominal pain on postoperative days 0-4 (p > 0.05).\n\n\nCONCLUSIONS\nMethylnaltrexone did not accelerate gastrointestinal recovery and did not affect opioid consumption or pain scores following short-segment spinal surgery as compared to placebo. Additional studies will be needed to identify effective opioid receptor antagonist dosing regimens for patients undergoing either short- or long-segment spinal arthrodesis procedures.