[Microanatomical study on the nutrient artery of facial nerve in cerebellopontine angle].

Objective: To explore the arterial origin of the facial nerve and the site of the arteries joining it in cerebellopontine angle (CPA), in order to provide anatomical data for clinical application.
Methods: The nutrient arteries were observed on 22 fresh adult head specimens fixed and perfused with formalin and gelatin under operation microscope.
Results: Of all the nutrient arteries of facial nerve motor root,31 were derived from the artery loops in CPA space (50.82%) and 17 from the branch of anterior inferior cerebellar artery (27.88%). Eight of them originated from the labyrinthine artery (13.1%), 3 from posterior inferior cerebellar artery (4.92%) and 2 from basilar artery (3.28%) respectively. Forty-seven nutrient arteries (77.05%) entered the proximal 1/3 segment of facial nerve motor root. Thirty-six nutrient arteries of nervus intermedius raised from the artery loops in CPA space (73.47%), 7 from the branch of anterior inferior cerebellar artery (14.29%) and 6 from labyrinthine artery (12.24%) respectively.
Conclusions: The observation of the arterial origin of the facial nerve and the site of the arteries joining it in cerebellopontine angle provided an anatomic basis for the etiology of hemifacial spasm and the microsurgical operation in CPA.