Vascular Malformations and Fistulas — WACS Viva & Clinical Scenarios (Cerebrovascular Disorders)

Exam-style vascular malformations and fistulas viva scenarios with examiner probes and model answers for Neurosurgery candidates.

Scenarios covered

• SCENARIO 1: A 28-year-old female presents with sudden severe headache, focal motor seizures, and right hemiparesis. Non-contrast cranial CT demonstrates a 3.5 cm lobar hematoma in the left precentral gyrus. Diagnostic four-vessel digital subtraction angiography confirms a pial arteriovenous malformation measuring 2.8 cm with feeding branches from the middle cerebral artery and drainage exclusively through the superior sagittal sinus. State the Spetzler-Martin and supplementary grading scores, assess the annual hemorrhage risk, and formulate a multimodal management strategy.
• SCENARIO 2: A 42-year-old man presents with progressive medically refractory focal epilepsy. Brain MRI shows a 1.5 cm well-circumscribed lesion in the right frontal lobe displaying reticulated mixed core signal intensity with a hypointense hemosiderin rim on T2- and susceptibility-weighted imaging, adjacent to a transmedullary collection of dilated veins forming a classic caput medusae pattern. Discuss the diagnostic findings, genetic considerations, and precise surgical indications and contraindications.
• SCENARIO 3: A 56-year-old woman presents with progressive pulsatile tinnitus, proptosis, conjunctival chemosis, and an audible left orbital bruit. Cranial catheter angiography demonstrates a high-grade dural arteriovenous fistula involving the left transverse-sigmoid junction with retrograde leptomeningeal venous drainage and venous ectasia, alongside an indirect carotid-cavernous fistula. Compare the Borden and Cognard classification schemes, quantify the risk of intracranial hemorrhage, and detail the endovascular and surgical options.
• SCENARIO 4: Following successful microsurgical resection of a high-flow, 5 cm frontoparietal arteriovenous malformation, a 34-year-old patient develops acute postoperative brain swelling and diffuse parenchymal hemorrhage in the adjacent brain parenchyma without an identifiable vascular source. Differentiate the pathophysiology of normal perfusion pressure breakthrough from occlusive hyperemia and outline the immediate neurointensive care management.
• SCENARIO 5: Outline the step-by-step microsurgical principles for resecting a ruptured Spetzler-Martin Grade II cerebellar arteriovenous malformation, detailing craniotomy selection, intraoperative neurovascular dissection sequence, handling of arterial feeders versus the primary draining vein, and post-resection confirmation of complete obliteration.