Preoperative three-dimensional multifusion imaging aiding successful microvascular decompression of a cerebellopontine angle lipoma: associated hemifacial spasm. Illustrative case

BACKGROUND: Cerebellopontine angle (CPA) lipoma–associated hemifacial spasm (HFS) is rare. As the removal of CPA lipomas has a high risk of worsening the neurological symptoms, surgical exploration is warranted only in selected patients. Preoperative identification of the lipoma affected site of the facial nerve, and offending artery are crucial for patient selection and successful microvascular decompression (MVD). OBSERVATIONS: Presurgical simulation using three-dimensional (3D) multifusion imaging showed a tiny CPA lipoma wedged between the facial and auditory nerves, as well as an affected facial nerve by the anterior inferior cerebellar artery (AICA) at the cisternal segment. Although a recurrent perforating artery from the AICA anchored the AICA to the lipoma, successful MVD was achieved without lipoma removal. LESSONS: The presurgical simulation using 3D multifusion imaging could identify the CPA lipoma, affected site of the facial nerve, and offending artery. It was helpful for patient selection and successful MVD.