Opioid Free Ureteroscopy: What is the True Failure Rate?

Objective: To determine the true failure rate of opioid free ureteroscopy (OF-URS) and rates of new-persistent opioid use utilizing a national prescription drug monitoring program. Material and Methods: We identified 239 patients utilizing our retrospective stone database who underwent OF-URS from Februrary 2018-March 2020. In Feb 2018, we initiated a OF-URS pathway (diclofenac, tamsulosin, acetaminophen, pyridium and oxybutynin). Patients who had a contraindication to NSAIDs were excluded from primary analyses. A prescription drug monitoring program was then utilized to determine the number of patients who failed OF-URS (defined as receipt of an opioid within 31 days of surgery) as well as rates of new-persistent opioid use (defined as receipt of opioid 91-180 days after surgery). All statistical analyses were performed using SAS 9.4. Tests were 2-sided and statistical significance was set at P<0.05. Results: We found a OF-URS failure rate of 16.6% and 14.0% in the total and opioid naïve cohorts, respectively. Rates of new-persistent opioid use were 0.9% and 1.2%, respectively (lower than published expected rate of ~6% after URS with postoperative opioids). 91% of patients obtained opioid from alternative sources. Uni/multivariate analyses were performed for both cohorts. In the total cohort, benzodiazepine users had a lower risk of OF-URS failure on multivariate analysis. No variables were associated with OF-URS failure in the opioid naïve cohort. Conclusion: The true failure rate of OF-URS is higher than previously thought at 16.6% and 14.0%. However, efforts to reduce opioid prescriptions with OF-URS pathways have successfully reduced new-persistent opioid use.