Endoscope-assisted microsurgery for microvascular compression syndromes.
OBJECTIVE: To discuss the results of endoscope-assisted surgery in microvascular decompression (MVD) of Cranial Nerves (CNs) V, VII, and VIII. METHODS: Neuroendoscopy was used as an adjunct to the surgical microscope in the MVD of the trigeminal (17 patients), facial (10 patients), and vestibulocochlear (1 patient) nerves in a series of 28 consecutive patients. After a standard microsurgical approach to CNs V, VII, and VIII, the endoscope was used to inspect all aspects of neural anatomy, to assess vascular compression, and to check the results of the decompression. Endoscope use was graded in four categories: Grade I, used but no definite role; Grade II, visualization assisted; Grade III, procedure assisted; and Grade IV, primary role. The usefulness of the endoscope was evaluated in each case. RESULTS: The endoscope was useful in visualizing the anatomy in all cases. It was especially useful in establishing trigeminal vein compression of CN V in Meckel's cave; observing multiple sources of vascular compression; ensuring adequate decompression after cauterization of vein, insertion of the Teflon felt, or a pexy procedure; and permitting observation of the compression of CN VII at the root exit zone by small arteries and veins. In six patients with trigeminal neuralgia, the trigeminal vein was cauterized and divided by using endoscopic vision only because the venous compression was not completely visualized with the microscope. During a follow-up period of 6 to 52 months (mean, 29 mo; median, 40 mo), all patients were asymptomatic and receiving no medication. CONCLUSION: The endoscope is a useful adjunct to MVD in the treatment of trigeminal neuralgia, hemifacial spasm, and disabling positional vertigo or tinnitus.