[Whole-range encirclement method versus conventional method for microvascular decompression for treatment of hemifacial spasm].

OBJECTIVE

To compare the efficacy and micromanipulation techniques of microvascular decompression with whole-range encirclement method and the conventional method in 65 cases of hemifacial spasm.

METHODS

The data of 65 surgically managed cases of hemifacial spasm were retrospectively analyzed for intraoperative findings, surgical techniques, and the patients' outcomes. Microvascular decompression with the conventional approach was performed in 30 patients (group A), and whole-range encircling method was used in the other 35 patients (group B). The patients were also divided into group C (below 40 years, n=27) and group D (above 40 years, n=38) according to the onset age of the symptom.

RESULTS

In these patients, 4 patterns of facial nerve compression were identified: simple contact, contact and indentation, adhesion and encasement, and unidentified offending vessels. The offending vessels included the arteries, veins, and vascular loops. In most patients in group C, the arachnoid membrane around the facial nerve thickened and encircled the offending ve;ssel; in group D, the characteristic changes of the vasculature occurred in the offending artery, resulting in its displacement. In groups A and B, the overall efficacy rate was 80% and 97.1%, with recurrence rates of 13.3% and 2.9%, respectively. The major permanent complications in group A included hearing impairment (10.0%) and ataxia (6.7%), whose incidences in group B were 2.9% and 2.9%, respectively.

CONCLUSION

Microvascular decompression with whole-range encircling method is a safe approach associated with high cure rate, in which careful avoidance of injuries to the cranial nerves and the penetrating vessels from the root entry/exit zone and the pons ensure good outcome and minimize the likeliness of recurrence and complications.