Venous compression as a cause of trigeminal neuralgia.

Aim: The study objective was to verify venous compression as a cause of trigeminal neuralgia (TN) and to define the optimal surgical tactics for TN patients.

Material And Methods: Four hundred twenty one patients were operated on for TN at the Neurosurgical Department of the City Hospital №2 from 1998 to 2015. Veins in the trigeminal nerve root entry zone, as a significant compression factor, were identified in 40 patients (9.5%). Intraoperative data, questionnaires, and self-assessment inventories were analyzed. Treatment outcomes were assessed using the Barrow Neurological Institute (BNI) scale.

Results: Patients with venous compression were divided into two groups. Eleven (27.5%) patients in the first group had isolated venous compression. The feature of microvascular decompression (MVD) in these patients was identification of all veins, vein mobilization, and, if possible, vein coagulation and resection. Resection of the vein along its course is a basic procedure to avoid recurrent neuralgia. The second group included 29 (72.5%) patients with a combination of venous and arterial compression. In these patients, a vein acted as an "assisting" compression factor: the vein changed the course of a compressing artery or nerve and exerted an additional compression effect on the nerve. The surgical tactics involved exploration of the trigeminal nerve root entry zone, arterial loop mobilization, and placement of a Teflon protector; venous vessels were coagulated and resected. The MVD efficacy was as follows: in group 1, 10 patients had a BNI score I-III, and 1 patient had a BNI score IV; in group II, 25 patients had a BNI score I-III, and 4 patients had a BNI score IV.

Conclusion: Venous compression can play both independent and assisting roles in the TN genesis. When exploring the trigeminal nerve, examination of the proximal trigeminal nerve is of particular importance, with paying attention to veins that may be a compression factor. In the case of isolated venous compression, the MVD surgical technique has some peculiarities, in particular coagulation and resection of veins compressing the trigeminal nerve root entry zone.