[Interposition and transposition techniques of vascular decompression for hemifacial spasm].

Objective: To analyze the vessels compressing facial nerve root exit zone and efficacy of interposition and transposition techniques of vascular decompression for hemifacial spasm.
Material and Methods: Vascular compression was evaluated in 110 patients. Implant interposition between vessels and nerve was performed in 52 cases, transposition of arteries without contact between implants and nerve - in 58 patients.
Results: Compressing vessels were anterior (44), posterior (61) inferior cerebellar, vertebral (28) arteries and veins (4). Multiple compressing vessels were found in 27 cases. Premeatal meningioma and jugular schwannoma were accompanied by vascular compression in 2 cases. Immediate regression of symptoms was observed in 104 patients, partial regression - in 6 patients. Transient facial paresis (4) and impaired hearing (5) were noted after implant interposition. Redo vascular decompression was performed in one case.
Conclusion: The most common compressing vessels were cerebellar arteries, vertebral artery and veins. Transposition of arteries is highly effective technique with low incidence of VII-VII nerve dysfunction but relatively slow regression of symptoms.