Functional and Hemodynamic Restoration After Microsurgical Resection of Compact High-Flow Temporo-Parieto-Occipital Arteriovenous Malformation

<b>Background/Objectives</b>: Arteriovenous malformations (AVMs) in the dominant temporo-parieto-occipital (TPO) junction of the brain are extremely rare and very difficult to remove surgically because this area includes multiple sensory and language networks. Due to the fact that many patients present with bleeding, surgeons have to find a delicate balance between removing all of the AVM tissue and preserving the functional areas of the brain where important functions occur. This study is reporting a case demonstrating how precise clinical-radiologic correlation, detailed anatomical knowledge, and deliberate microsurgical techniques can allow safe removal of the AVM and improve the patient's neurologic function without the need for additional intraoperative technology. <b>Case Presentation</b>: A 47-year-old right-handed male patient experienced persistent neurological deficits after experiencing a hemorrhage from an AVM in his dominant posterior hemisphere, which included mild language difficulties, right hemifacial-brachial spasticity, parietal sensory loss and a visual field defect of his right eye known as an inferior quadrantanopia localized to the TPO junction. Cerebral angiography identified a small, compact, high-flow AVM (40 × 30 mm) fed by distal branches of the middle cerebral artery (M4), posterior cerebral artery (P4), anterior cerebral artery (A4), as well as a small branch of the superior cerebellar artery (SCA). Blood drained into two veins of the Trolard and Labbé. The authors removed the AVM completely by circumferential dissection of the nidus along gliotic planes using a microscope. Feeders were then sequentially disconnected, and the venous outflow was preserved until the AVM could be removed en bloc. Post-operative angiograms demonstrated complete removal of the AVM with normalization of blood flow to the surrounding cortex. The patient's neurologic function improved over time and at three months post-operatively, he was functioning independently (modified Rankin Scale = 1; Barthel Index = 100) and there was no evidence of residual nidus or edema on imaging. <b>Conclusions</b>: High-flow AVMs in the dominant TPO junction can be completely removed using a disciplined microsurgical approach and a feeder first/vein last disconnection method based on anatomy. The patient's improvement in function represented reperfusion and reintegration of an injured but still functional network of the brain, reinforcing the idea that careful observation, a deep understanding of brain anatomy, and restrained surgical technique are critical to achieving long-term results in AVM surgery.