Utility of Continuous Paravertebral Block After Retroperitoneal Abdominal Aortic Aneurysm Repair

Abstract

Open abdominal aortic aneurysm (AAA) repairs can be associated with significant pain and morbidity. Previous studies have demonstrated utility of adjunctive epidural analgesia (EA) in addition to general anesthesia (GA) to reduce pain and blunt the maladaptive surgical stress response. However, EA may be complicated by epidural hematomas and severe hypotension. Recently, we started using continuous paravertebral block (PVB) for perioperative analgesia after retroperitoneal AAA repair. PVB has some distinct advantages over EA such as unilateral localization, reduced risk of hypotension, and minimal risk of epidural hematoma in the setting of systemic heparinization. This study aimed to examine the utility of PVB by comparing total opioid consumption in the postoperative period among patients who received GA+PVB and those who received GA alone. This retrospective matched cohort study included 62 patients who underwent elective retroperitoneal AAA repair between January 2019 and August 2022. Thirty-one subjects managed with GA+PVB were compared with 31 control subjects treated with GA alone, matched on following criteria: age, sex, and cross-clamp location. Outcome measures included total opioid analgesics administered during their inhospital postoperative course, time to extubation, time to return to baseline activity, time to normal bowel function, and length of stay. Opioid doses were converted to morphine milligram equivalents (MMEs). The GA+PVB group required significantly less opioid analgesics (81±53 MME) than the GA group (171±121 MME) (P<0.001). Compared to GA alone, GA+PVB was superior in every clinical metric examined: time to extubation (3 vs. 1hr, P<0.001), recovery of bowel function (3 vs. 2days, P=0.002), recovery of baseline physical activity (4 vs. 2days, P=0.019), and length of stay (5 vs. 3days, P<0.001). Continuous paravertebral block provides better pain management with significantly decreased opioid requirements in the postoperative period compared to GA-alone for patients undergoing elective retroperitoneal AAA repair.