Pain Outcomes Following Endoscopic Microvascular Decompression for Trigeminal Neuralgia Based on Vascular Compression Type

Abstract

Background: Arterial compression of the trigeminal nerve at the root entry zone has been the long-attributed cause of compressive trigeminal neuralgia despite numerous studies reporting distal and/or venous compression. The impact of compression type on patient outcomes has not been fully elucidated. Objective: We categorized vascular compression based on vessel and location of compression to correlate pain outcomes based on compression type. Methods: A retrospective video review of 217 patients undergoing endoscopic microvascular decompression for trigeminal neuralgia categorizing vascular compression into 5 distinct types, proximal arterial compression (VC1), proximal venous compression (VC2), distal arterial compression (VC3), distal venous compression (VC4), and no vascular compression (VC5). Vascular compression type was correlated with post-operative pain outcomes at one month (n=179) and last follow up (mean= 42.9 months, n=134). Results: At one month and longest followup, respectively, pain was rated as “much improved” or “very much improved” in 89% & 69% of patients with VC1, 86.6% & 62.5% of patients with VC2, 100% & 87.5% of patients with VC3 83% & 62.5% of patients with VC4 and 100 &100% of patients with VC5. Multivariate analysis demonstrated VC4 as a significant negative of predictor pain outcomes at one month, but not longest followup, and advanced age as a significant positive predictor. Conclusions: The degree of clinical improvement in all types of vascular compression was excellent but at longest follow up vascular compression type was not a significant predictor out outcome. However distal venous compression was significantly associated with worse outcomes at one month.