Long-term outcome of endoscope-assisted microvascular decompression in trigeminal neuralgia.

Objective: The therapy of choice for classical trigeminal neuralgia (TN) is usually microvascular decompression (MVD). Although in most surgical procedures the view with the operating microscope is sufficient to inspect the entire course of the trigeminal nerve from the brainstem to Meckel's cave, anatomical abnormalities may hinder the view. In these conditions, visualization with an endoscope with an angulated view provides additional exposure and may identify a compression that was hidden on microscopic view. The authors report their experience with this endoscope-assisted microvascular decompression (EA-MVD) technique and provide long-term results.

Methods: Between 2000 and 2020, 182 patients with classic TN and radiologically and intraoperatively confirmed neurovascular conflict (NVC) underwent endoscope-assisted surgery. Follow-up was conducted via our outpatient clinic or by telephone interview. EA-MVD included endoscopic inspection and dissection, as well as bimanual dissection under the microscope. The influence of several factors on postoperative outcome was statistically analyzed.

Results: In total, 168 (92%) of the authors' patients showed complete pain relief immediately postoperatively, 12 only partial relief, and 2 reported no improvement at all (1 with venous compression). Seventeen patients were unavailable for follow-up. The mean (range) follow-up duration was 62 (3-240) months. On last follow-up, 143 patients (78.6%) had a very good outcome (Barrow Neurological Institute [BNI] score I/II), 34 (18.7%) reported a moderate outcome (BNI score III), and 5 patients' outcomes (2.8%) were classified as failures (BNI score IV/V). Twenty-five patients (13.7%) had recurrence of pain. The average pain-free interval until recurrence was 25 months. The use of the endoscope was classified as very beneficial in 29 operations (15.9%). Major complications occurred in 4 patients (2.2%). Only the number of affected trigeminal branches showed a significant impact on outcome, with a single affected branch associated with better outcome. Duration of symptoms, sex, affected side, type of compression, and number of NVCs showed no correlation with outcome.

Conclusions: The authors results confirmed that EA-MVD is a safe technique with a high success rate. The value of the endoscope is especially apparent in patients with a prominent suprameatal tubercle that obscures the straight view to Meckel's cave with the operating microscope.