Does microsurgical vascular decompression for trigeminal neuralgia work through a neo-compressive mechanism? Anatomical-surgical evidence for a decompressive effect.

The positive effect of Microsurgical Vascular Decompression (MVD) on idiopathic trigeminal neuralgia still remains controversial between a decompressive mechanism and a "neo-compressive" one. This paper is a summary of a comparative study of the results on pain obtained with two technical modifications of the MVD procedure. The first consisted of interposition of a foreign material between the nerve and the transposed artery after dissection of the trigeminal nerve, whilst in the second the offending vessel(s) was dislodged without using any material touching the nerve. The two series of 60 patients in each were similar concerning the clinical features. Evaluation of results on neuralgia - with one year follow-up-in both series, shows that the technique used in the second group was not followed by a higher rate of recurrence than the technique used in the first group. On the contrary; 4.5% in the 2nd group compared to 10% in the first. This indicates that MVD would not act as a result of "neo-compression" of the nerve, but rather through a real decompressive mechanism.