Surgical Concept and Long-Term Outcomes of Various Case-by-Case Decompressive Techniques for Trigeminal Neuralgia Caused by the Trigeminocerebellar Artery

BACKGROUND AND OBJECTIVES: Trigeminocerebellar artery (TCA) is known as a causable artery of trigeminal neuralgia (TN) because this anomalous artery has unfavorable anatomic features to perform the microvascular decompression. We aimed to clarify the long-term outcomes of TN caused by TCA and demonstrate surgical concepts with various techniques for its treatment. METHODS: Patients who underwent surgeries for TN by TCA were retrospectively reviewed with intraoperative findings, surgical techniques, and long-term outcomes were investigated. RESULTS: Surgical treatments of TN were performed on 146 patients, and 13 patients (9%) had symptoms owing to TCA. Patients in TCA group (average age: 59.1 years; sex [male:female = 3:10]; affected side [right:left = 10:3], affected area [V2: 8; V3: 1; V1 + 2: 3; and V2 + 3: 1]) had TCAs with the following anatomic characteristics: penetration of the trigeminal nerve (8 patients; 62%) and presence of several perforators (all patients) (median: 3 branches). Various surgical techniques (transposition: 5 patients [38.5%]; arterial reshaping: 1 patient [12.5%]; arterial reshaping + interposition: 2 patients [25.0%]; and partial sensory rhizotomy + transposition: 5 patients [62.5%]) were applied as required. Although 1 patient required postoperative oral medication, the other 12 patients (92%) experienced complete symptom resolution immediately after the surgery, and no recurrence was observed during the median follow-up period of 72 months. CONCLUSION: This study among 146 patients with TN observed 13 patients (9%) caused by TCA and confirmed the favorable long-term outcomes in 12 patients (92%) with complete resolution of symptom without recurrence. As TCA has disadvantageous anatomic structures to be separated from trigeminal nerve, to treat TN caused by TCA, contemporary standard techniques are insufficient at times and various case-by-case surgical techniques must be required.