{Reference Type}: Case Reports {Title}: Intraoperative venous congestion and brainstem venous hemorrhagic infarction during retrosigmoid for acoustic neuroma. {Author}: Wu EM;Abdelsalam A;Morcos JJ; {Journal}: Clin Neurol Neurosurg {Volume}: 231 {Issue}: 0 {Year}: 2023 08 10 {Factor}: 1.885 {DOI}: 10.1016/j.clineuro.2023.107827 {Abstract}: Venous hemorrhagic infarction is rare but can occur during acoustic neuroma resection [1-5]. We present the case of a 27-year-old male with 1.5 years of progressive headaches, tinnitus, imbalance and hearing loss. Imaging revealed a left Koos 4 acoustic neuroma. The patient underwent a retrosigmoid approach for resection. During surgery, a vein of significant size within the capsule of the tumor was encountered and was necessary to take to proceed with resection. After coagulation of the vein, intraoperative venous congestion with cerebellar edema and hemorrhagic infarction ensued, requiring resection of a portion of the cerebellum. Given the hemorrhagic nature of the tumor, continuing tumor resection was necessary to prevent postoperative hemorrhage. This was carried out until hemostasis was achieved. 85 % resection was achieved, leaving a residual against the brainstem and cisternal course of the facial nerve. Postoperatively, the patient required 5 weeks hospitalization followed by 1 month of rehabilitation. At discharge to rehabilitation, patient had trach, PEG, left House-Brackmann 5 facial weakness, left sided deafness, and right upper extremity hemiparesis (1/5). At 7 months follow up, he continued to have left House-Brackmann 5 facial weakness and left sided deafness but trach and PEG had been removed and strength had improved to 5/5. We demonstrate in this video the unfortunate and rare occurrence of intraoperative venous hemorrhagic infarction during acoustic neuroma resection - particularly for large tumors in young patients - and discuss its etiology and surgical steps that are necessary to partially remedy its devastating impact on the patient. The patient consented to the procedure and participating in this surgical video.