Related Experiment Video
Updated: Jan 26, 2026

Single-Port Robotic-assisted Transaxillary Breast-conserving Surgery: A Prospective, Single-arm, Non-randomized Phase IIa Clinical Trial
Published on: August 19, 2025
The Impact of Alvimopan on Return of Bowel Function After Major Spine Surgery - A Prospective, Randomized,
Lauren K Dunn1, Robert H Thiele1,2, Michelle C Lin1
1Department of Anesthesiology, University of Virginia, Charlottesville, Virginia.
Background:
Pain management following major spine surgery requires high doses of opioids and is associated with a risk of opioid-induced constipation. Peripheral mu-receptor antagonists decrease the gastrointestinal complications of perioperative systemic opioid administration without antagonizing the analgesic benefits of these drugs.
Objective:
To investigate the impact of alvimopan in opioid-naive patients undergoing major spine surgery.
Methods:
Patients undergoing >3 levels of thoracic and/or lumbar spine surgery were enrolled in this prospective, randomized, double-blind study to receive either alvimopan or placebo prior to and following surgery. Opioid consumption; pain scores; and time of first oral intake, flatus, and bowel movement were recorded.
Results:
A total of 24 patients were assigned to the active group and 25 were assigned to the placebo group. There was no significant difference in demographics between the groups. Postoperatively, the alvimopan group reported earlier time to first solid intake [median (range): alvimopan: 15 h (3-25) vs placebo: 17 h (3-46), P < .001], passing of flatus [median (range): alvimopan: 22 h (7-63) vs placebo: 28 h (10-58), P < .001], and first bowel movement [median (range): alvimopan: 50 h (22-80) vs placebo: 64 h (40-114), P < .001]. The alvimopan group had higher pain scores (maximum, minimum, and median); however, there was no significant difference between the groups with postoperative opioid use.
Conclusion:
This study shows that the perioperative use of alvimopan significantly reduced the time to return of bowel function with no increase in postoperative opioid use despite a slight increase in pain scores.
Related Concept Videos
Blind Procedures
Major Hormones and Their Functions
Oxytocin, produced in the hypothalamus and released by the pituitary gland, plays a role in social bonding, childbirth, and...
Blinding
Bioequivalence Experimental Study Designs: Completely Randomized and Randomized Block Designs
Venous Return
What is Venous Return?
Venous return refers to the rate at which blood flows back to the heart from the body's peripheral veins. It's an integral part of the circulatory system...
Major Organs of the Digestive System
Gastrointestinal tract:

