Abstract No. 219 Rethinking median arcuate ligament syndrome: the role of celiac plexus block for diagnosis

Abstract

To evaluate celiac plexus block (CPB) as a preoperative diagnostic tool for median arcuate ligament syndrome (MALS) A retrospective cohort study of 96 clinically diagnosed MALS patients that underwent 103 CT-guided percutaneous CPB at a single hospital between January 1, 2017, and April 3, 2020. Clinical, imaging, and procedural reports were reviewed. A CPB database was established. Numeric rating scale-11 was used to self-report pain scores. Primary outcomes were technical success, pain score, nausea, and vomiting. A total of 96 patients (75 female) with a mean age of 26.7 years. Computed tomography (CT) imaging was available for review in 81 of 96 patients. CT findings of MALS including low-lying median arcuate ligament, celiac artery stenosis, inferiorly displaced celiac trunk, or celiac trunk hook-shaped configuration was present in 22/81 patients. There were no differences in post-CPB pain relief between patients with normal anatomy findings versus MALS anatomy (P = .7447).Technical success was achieved in 102 of 103 cases. Postprandial pain score decreased from 6.3 to 0.9 points (P< .0001). Postprandial nausea decreased from 37.9% to 11.6% (P< .0001). Postprandial vomiting decreased from 15.5% to 4.9% (P = .0194). No major adverse events and one moderate adverse event were reported. Subsequently, 45.8% of patients elected to undergo MALS surgery: exploratory laparotomy with median arcuate ligament resection and celiac ganglionectomy. Patients electing for MALS surgery had significantly higher pre-CPB pain scores (7.0 versus 5.6 points, P = .023) and lower post-CPB pain scores (0.4 versus 1.3 points, P = .043) when compared to patients that did not pursue surgery. MALS is not an arteriopathy, but rather an autonomic neuropathy responsive to local anesthetic block. In our series of 103 CPB, we reported pain relief in 83.5%, regardless of CT findings of arterial involvement. The degree of response to CPB correlates with the decision to undergo MALS surgery. CPB is safe and central to the preoperative diagnosis of MALS.