Impact of transversus abdominis plane block on length of stay and postoperative opioid use in anterior lumbar interbody fusions.

Background: Anterior lumbar interbody fusion (ALIF) is an increasingly common surgical procedure for a variety of spinal pathologies. As both opioid use and healthcare costs remain major national healthcare crises, it is crucial to understand methods of effective pain management in spine surgery, including regional anesthesia. While transversus abdominis plane (TAP) blocks are also commonly performed for anterior spinal surgery, literature evaluating outcomes after TAP blocks for ALIF patients is sparse. This retrospective cohort study aims to determine the effect of TAP blocks on perioperative opioid use and hospital length of stay.

Methods: Retrospective chart review was performed for patients 18 years or older undergoing 1- or 2-level ALIF with or without posterior percutaneous instrumented fusion. Baseline demographics, surgical details, length of stay (LOS), and data on inpatient opioid use (converted to morphine milliequivalents, MME) was collected. Total MME and MME stratified by postoperative day (POD) was collected. Bivariable and multivariable regression models were used to analyze the relationship of TAP blocks with LOS and narcotic use postoperatively.

Results: About 295 patients were included, with 102 (34.6%) undergoing TAP block and 193 (65.4%) patients without TAP block. There were no significant differences in baseline patient characteristics. Use of a TAP block had no statistically significant effect on LOS, and bivariable analysis revealed no effect when groups were analyzed by sex, age, BMI, preoperative opioid use, or number of levels fused. TAP block patients received significantly more MME on POD 0 and on combined POD 1 and 2 than those without a TAP block. Bivariable analysis did not reveal any subgroup who benefitted from a TAP block.

Conclusions: With the largest patient cohort reported to date, we found no statistically significant improvements in length of stay or short-term postoperative opioid usage when patients received TAP blocks for anterior lumbar interbody fusion.