To discuss the microsurgical treatment, outcomes and complications of trigeminal neuralgia (TN) caused by non-arterial compression factors.

A total of 251 patients with complete clinical data of TN undergoing microsurgical treatment at Department of Neurosurgery, China-Japan Friendship Hospital from May 2006 and December 2016 by the same surgeon were retrospectively enrolled into this study. Among them, 36 (14.3%) patients were caused by non-arterial compression factors. Of the 36 patients, 19 (52.8%) were caused by single offending venous compression, of which 12 cases underwent microvascular decompression (MVD), 7 cases over 60 years old underwent selective partial rhizotomy (PR) after MVD; 17 (47.2%) cases had no offending vessels, of which 12 cases underwent radical release of trigeminal nerve root, and the trigeminal nerve root was completely dissected from the brain stem to the Meckel's cave, and 5 cases over 60 years old underwent additional PR. Evaluation of efficacy was based on the Brisman criteria.

Among 19 patients with single venous compression, 11 cases of 12 patients showed immediate effect post MVD, and 1 case did not; all the 7 patients with unsatisfactory decompression undergoing PR showed immediate effect after operation. Among 17 patients without definite offending vessels, 11 cases of 12 patients with completely trigeminal nerve release demonstrated immediate effect after operation, 1 case did not; and 5 cases with additional PR showed immediate effect after operation. The total effective rate was 94.4% (34/36) immediately after operation. Postoperative neurological complications occurred in 3 (8.3%) cases including 1 case of tinnitus, 1 case of diplopia and 1 case of masticatory weakness. Thirty-six patients were followed up from 14 to 142 months, and the average follow-up time was 67.0±9.2 months. The total effective rate was 88.9% (32/36) and the recurrence rate was 5.9% (2/34). The patients with no relief or recurrence obtained improvement after radiofrequency and gamma knife therapy. Three patients with neurological complications recovered after conservative treatment during the follow-up period.

MVD could be performed in patients with single venous compression after complete dissociation of the offending vein. Adhesion around the trigeminal nerve sensory root should be fully released in patients without offending vessels compression. PR of the trigeminal nerve sensory root should be performed in patients over 60 years old. After the treatment of TN with non-arterial compression, the outcome was satisfactory, and there was no increase in operative complications.

Trigeminal neuralgia; Microsurgery; Treatment outcome; Non-arterial compression; Offending vessels