Standard operating procedure and surgical technique innovation in fully endoscopic microvascular decompression for trigeminal neuralgia: technical note on 189 patients.

BACKGROUND: Microvascular decompression (MVD) is a well-established and effective treatment for primary trigeminal neuralgia (TN). Endoscopy has been implemented to provide a comprehensive view of neurovascular conflict and minimizes the damages of brain retraction during MVD. OBJECTIVES: To preliminarily evaluate the surgical safety and efficacy of fully endoscopic microvascular decompression (EMVD) for primary TN with surgeon performing two-hand manipulation and assistant holding endoscope. METHODS: Retrospective clinical analysis of 189 patients with primary TN underwent EMVD between June 2019 and August 2022 was performed. By analyzing the intraoperative situation, the outcomes of postoperative symptoms and the main complications, we evaluated the reliability and effectivity of the operative technique in the treatment of primary TN. RESULTS: We summarized the standard operating procedure of EMVD for primary TN with surgeon performing two-hand manipulation and assistant holding endoscope. In addition, acicular bipolar electrocoagulation technique was developed to handle venous compression. During the follow-up period, good pain relief was achieved in 178 patients (94.2%) and recurrence of pain was observed in 4 patients (2.1%). Postoperative temporary complications included trigeminal dysesthesias (7 patients, 4.8%), cerebrospinal fluid leak (2 patients, 1.1%), hearing difficulty (3 patient, 1.6%), facial paresis (2 patients, 1.1%) and vertigo (5 patients, 2.7%). There were no cases of intracranial hemorrhage, cerebellar swelling and death. CONCLUSION: This EMVD technique is reliable and effective, and can be used as a routine surgical procedure for primary TN.

Fully Endoscopic Microvascular Decompression for Trigeminal Neuralgia Caused by Vertebrobasilar Artery: A Case Series Review: 2-Dimensional Operative Video.

BACKGROUND AND OBJECTIVE: Microvascular decompression (MVD) is the most definitive and preferred surgical treatment for trigeminal neuralgia (TN). Treatment of TN caused by the vertebrobasilar artery (VBA) has been reported to be challenging and less satisfactory in complications and recurrence. Endoscopy has been implemented to provide a comprehensive view of neurovascular conflicts and minimize brain tissue stretch injury while exploring the trigeminal nerve. However, there are few retrospective studies on the treatment of TN caused by VBA by fully endoscopic microvascular decompression (E-MVD). This article aimed to illustrate the safety and efficacy of E-MVD for TN caused by the VBA. METHODS: Clinical data for 26 patients with TN caused by the VBA who underwent E-MVD from 2019 to 2022 were retrospectively analyzed. The characteristics of vertebrobasilar-associated TN were summarized. The safety and efficacy of E-MVD for vertebrobasilar-associated TN were estimated based on the analysis of intraoperative manipulation, postoperative symptom relief, and complications. RESULTS: Intraoperatively, the vertebrobasilar artery was regarded as a direct offending vessel in all 26 patients with TN, the vertebral artery in 18 (69.23%) and the basilar artery in 10 (38.46%). In addition to the vertebrobasilar artery, other vessels involved included the superior cerebellar artery in 12 patients, anterior inferior cerebellar artery in 9, posterior inferior cerebellar artery in 1, and veins in 4. All patients underwent E-MVD, and TN was entirely resolved in 26 (100%) patients immediately postoperatively. During the follow-up period of 12-45 months, no recurrence or serious complications were found. There were no serious postoperative complications, such as cerebellar swelling, intracranial hemorrhage, or death. CONCLUSION: E-MVD for vertebrobasilar-associated TN is effective and safe.

Interaction between PD-L1 and soluble VEGFR1 in glioblastoma-educated macrophages.

PURPOSE: The combined application of immune checkpoint inhibitors (ICIs) and anti-angiogenesis therapy has shown synergistic effects on glioblastoma (GBM). As important resources of PD-L1 in the tumor microenvironment (TME), tumor-associated macrophages (TAMs) have significant impact of the efficiency of ICIs. However, the effects of anti-angiogenesis agents on immune checkpoints expression are not fully understood. METHOD: GBM-educated macrophages were generated from circulating monocytes of healthy controls and GBM patients under the education of GBM cell line. Surface expression of PD-L1 and VEGFR1 on GBM-educated macrophages was analyzed. VEGFR1 NAb and soluble VEGFR1 (sVEGFR1) were added and their effects on PD-L1 expression on TAMs was investigated. Serum soluble PD-L1 (sPD-L1) and sVEGFR1 levels in GBM patients were measured and their correlation was analyzed. RESULT: The expression intensity of PD-L1 on GBM-educated macrophages was higher and its up-regulation partially depends on VEGFR1 signaling pathway. GBM-educated macrophages secreted less levels of soluble VEGFR1 (sVEGFR1), and exogenous sVEGFR1 down-regulated PD-L1 expression intensity. PD-L1 blockade promoted the secretion of sVEGFR1. Finally, sVEGFR1 and sPD-L1 in serum of GBM patients were overexpressed, and a positive correlation was found. CONCLUSION: These findings reveal the interaction between PD-L1 and VEGFR1 signaling pathway in GBM-educated macrophages. VEGFR1 is involved with PD-L1 overexpression, which can be impeded by autocrine regulation of sVEGFR1. sVEGFR1 secretion by GBM-educated macrophages can be promoted by PD-L1 blockade. Taken together, these findings provide evidences for the combined application of ICIs and anti-angiogenesis therapies in the treatment of GBM.