Microvascular Decompression of Facial Nerve and Pexy of the Left Vertebral Artery for Left Hemifacial Spasm: 3-Dimensional Operative Video.

Abstract

A 73-yr-old man presented with intractable left hemifacial spasm of 4 yr duration. Brain magnetic resonance imaging showed significant compression of left facial nerve by the left vertebral artery (VA) and anterior inferior cerebellar artery (AICA).The patient underwent a left retrosigmoid craniotomy and a microvascular decompression of the cranial nerve (CN) VII. Intraoperatively, we found that the distal AICA had a protracted subarcuate extradural course.1 This was relieved by intra/extradural dissection. The left VA and the AICA loop were compressing the root exit zone of CN VII. The VA was mobilized, and pexy into the petrosal dura was done with 8-0 nylon sutures (Ethilon Nylon Suture, Ethicon Inc, a subsidiary of Johnson & Johnson, Somerville, New Jersey). Once this was done, the lateral spread disappeared.2 The AICA loop was decompressed with 2 pieces of Teflon felt (Bard PTFE felt, Bard peripheral Vascular Inc, a subsidiary of CR Bard Inc, Temp, Arizona). After this, wave V of the brainstem auditory evoked potential (BAEP) disappeared completely, with no recovery despite the application of the nicardipine on the internal auditory artery (IAA). The IAA appeared to be stretched by the microvascular decompression. Arachnoidal dissection was done to release the CN VIII and an additional felt piece was placed to elevate the AICA loop; the BAEP recovered completely. The patient had a complete disappearance of the hemifacial spasm postoperatively, and hearing was unchanged.This 3-D video shows the technical nuances of performing a vertebropexy, release of the AICA from its extradural subarcuate course, and the surgical maneuvers in the event of an unexpected change in neuromonitoring response. The suture technique of vertebropexy is preferred to a loop technique, to avoid kinking of the VA.3Informed consent was obtained from the patient prior to the surgery that included videotaping of the procedure and its distribution for educational purposes. All relevant patient identifiers have also been removed from the video and accompanying radiology slides.