gms | German Medical Science

Objective: To evaluate the value of endoscope assistance in microvascular decompression for hemifacial spasm.

Method: 116 patients (73 female, 43 male, mean age 56 years) suffering from hemifacial spasm underwent an endoscope-assisted microvascular decompression via a lower retrosigmoid approach. The spasm was left in 77 patients and right in 39 patients.

Results: The use of the endoscope was safe. There was no endoscope- related nerve or vessel injury and morbidity respectively. In 36 patients, the compression site could not be visualized with the microscope because the AEP were affected while retracting the cerebellum. In contrast, all vascular compression sites were identified without any retraction with the 30° or 45° endoscope. In 111 patients, we found a typical arterial compression of the root exit zone of the facial nerve. The offending vessel was AICA (28), PICA (38), VA (3) and combined compression by VA/PICA (17), VA/AICA (16), PICA/AICA (6) und VA/PICA/AICA (3). In one patient, we found a vein, and in 4 patient a venous/arterial sandwich compression (2 AICA/vein and 2 PICA/vein). In 79 patients, we have a mean follow-up time of 12 months. Almost half of the patients (36) was spasm-free immediately after surgery. In 66 patients (83.5 %), the spasm disappeared. In 9 patients, the spasm improved by 50 %. In 4 patients, there was no improvement. In all of these patients, we found anatomic anomalies. After 18 months (56 patients), the success rate improved to 87.5 %. There was no mortality. In 28 patients (24 %), neurological deficits occurred after surgery, but these were permanent only in 5 patients (4 %) (2 anacusis, 2 hypacusis, 1 dizziness).

Conclusions: The endoscope-assisted microsurgical technique to decompress the facial nerve is a safe technique. The use of endoscopes improves the visualization of the nerve in its entire course through the subarachnoid space without any retraction. Especially in far dorsomedially located compression sites, the endoscope was invaluable to inspect the compression site. Obviously, the rate of hearing loss can be reduced with the endoscope-assisted technique.