Microvascular decompression of the trigeminal nerve: experience of five years

Shulyov Yu.A., Gordienko K.S., Rudenko V.V., Bikmullin V.N., Vorobyov A.V., Rychkov V.V., Krutikov B.S.

(Đity Multi-Field Hospital N 2, Medical Academy of Postgraduate Education, Saint Petersburg, Russia)

The rate of trigeminal neuralgia (TN) is equal to 1 case per 25 000 men. An average age of the diseased and patients subject to surgical treatment is 55 and 63 years respectively.

Theories of TN development are contradictory. The most logic theory, explaining a mechanism of TN development and confirmed by efficacy of microvascular decompression of the trigeminal nerve (MVD), is a conflict between a vessel and the nerve trunk.

We stick to the opinion, that MVD is a principal pathogenetic method of TN treatment. It allows to do away with the main cause of classic TN and to get stable recovery. Thanks to the method, worked out by Janetta P. and representatives of his scientific school (Janetta P. et al., 1998), who have an experience of more than 2000 operations, performed during 20 years, MVD has become a generally accepted and reproducible operation in treatment of this severe pathology.

Success of surgical treatment is strongly dependent on careful selection of patients and strict observance of surgical technologies.

The goal of Investigation

  1. To estimate possibility of wide use of MVD in Russia.
  2. To confirm better efficacy of treatment in decompression of the most proximal segment of the trigeminal nerve.
  3. To work out a system of methods for effective and safe introduction of MVD in Russia.

Materials and Method

We performed 55 operations for TN, caused by a neurovascular conflict (49 cases) and tumor of a temporal bone pyramid (diagnosis was verified before operation). Duration of the disease varied from 1 up to 30 years. Preoperative diagnosis included a clinical examination with use of standardized questionnaires (Facial Pain Survey 2000, McGill Questionnaire) and scales (Visual Analogue Scale, Verbal Scale), methods of neurovisualization (CT, MRI, Transcranial Doppler, cerebral angiography).Clinical criteria of selection were short-lasting, paroxysmal, cutting and severe pain in projection of zones of innervation of the trigeminal nerve branches, presence of trigger zones, a positive effect of carbamazepine at an early stage of the disease. A retrosigmoid approach and an operating microscope (Carl Zeiss Opmi CS) were used during the operation. A patient was in a lateral position. Success of surgical treatment was dependent on the following:

  1. Careful preoperative planning, based on correct positioning of a patient with taking into account a skull form and its structure, a neck length.
  2. Rigid three-point fixation of a patient's head (we used Mayfield's clip).
  3. Use of an operating microscope.
  4. High technology of microsurgical intervention (retraction-free surgery).
  5. Use of modern nerve protectors (Teflon implants).
  6. Intraoperative monitoring.

Results

Excellent (complete regress of symptoms) and good (periodic minor pain, which did not demand taking drugs) results were watched in 50 (91%) and 3 (5.4%) patients respectively. Reoperation (decompression of the trigeminal nerve trunk) in 2 (3.6%) cases was conditioned by recurrence of pain syndrome. Results of reoperation were considered to be good. Complications were watched in 2 patients (otoliquorrhea through cells of the mastoid process; reoperation consisted in cell tamponade).

Conclusion