[Microsurgical treatment of trigeminal neuralgia. Results and prognostic factors of microsurgical vascular decompression].

The authors have reviewed 100 cases of trigeminal neuralgia operated upon at the cerebello-pontine angle using microsurgical techniques, i.e. 20% of their total series of 513 patients with tic douloureux, 413 of them having been submitted to percutaneous R.F.--thermocoagulation. In 10 of the above 100 patients, a tumour or an angioma have been found and with its removal a total relief of pain has been obtained. In all but three of the other 90 patients, a neurovascular conflict has been revealed. In 17 of them a selective section of the trigeminal root had to be performed, as its cross-compression could not be eliminated. A total cure was achieved in all but three cases in which the result was only partial. In 70 patients a microvascular decompression (MVD) was performed and in 68 of them a follow-up of 1 to 5 years has been analyzed. In 82.4% the results were excellent. Further 7.3% thought to be benefited by the operation; although they still had some pain, they were well controlled by medical treatment. In 10.3% an unsatisfactory improvement, failure or recurrence were noted. Then a critical study of the whole material has been made in search for the causes of unsatisfactory results and for the possibilities of making the efficacity of MVD ascertained in a higher percentage of patients. The results of this study lead to definite conclusions, a part of which is quoted below: Some of clinical findings showed to be of paramount importance for the prognosis. The most evident has been a highly significant difference in the percentage of a total cure in patients with attacks of tic douloureux only (94.5%) and in those with the same type of attacks, but associated with permanent pain (58.3%). The analysis of the operative findings and of the details of the surgical procedure indicated to a necessity of restitution of the normal shape and course of the trigeminal root from the petrous ridge up to the entry-zone and of an adequate root protection (for instance with Dacron), after the Vth nerve had been detached from the conflicting vessel. A correlation of the above findings with the angiographic ones has been made. A measurable method has been used to make available data which could be informative as to the presence of a conflict, as well as to its anatomical cause. But this still needs a further critical elaboration.