Cerebral Revascularization After the Carotid Occlusion Surgery Study

What Candidates Remain, and Can We Do Better?

Timothy G. White, MD; Hussam Abou-Al-Shaar, MD; Jung Park, MD, PhD; Jeffrey Katz, MD; David J. Langer, MD; Amir R. Dehdashti, MD


Neurosurg Focus. 2019;46(2) 

In This Article

Illustrative Cases

Case 1

A 58-year-old man with a history of stroke, TIA, hypertension, hyperlipidemia, and atrial fibrillation who was on coumadin and DAPT presented to the hospital with left facial droop, hand weakness, and numbness. MRI revealed right MCA territory acute infarcts and angiography demonstrated right ICA occlusion with no filling of the right ICA (Figure 1A and B). QMRA NOVA demonstrated right ICA occlusion with a small amount of collateral flow from the right posterior communicating artery, and follow-up SPECT with Diamox challenge revealed right-sided hypoperfusion with decreased CVR (Figure 1C). Given the imaging evidence of right-sided hypoperfusion as well as recurrent strokes on DAPT, a right-sided STA-MCA flow augmentation revascularization was offered and, after a discussion of the risks and benefits, the patient chose to undergo the procedure. Postoperatively the patient experienced no complications, with postoperative imaging showing a patent bypass graft (Figure 1D). One year after the initial bypass the patient had no further evidence of stroke.

Figure 1.

Case 1. A: MRI, diffusion-weighted imaging (DWI). B: Conventional angiography demonstrating occlusion of the right ICA. C: QMRA NOVA demonstrating right ICA occlusion with a small amount of collateral flow from the right posterior communicating artery. Numbers represent the volumetric flow rate (ml/min). D:Postoperative CTA showing patent bypass. BA = basilar artery; LACA = left ACA; LCCA = left common carotid artery; LICA = left ICA; LPCA = left posterior cerebral artery; LVA = left vertebral artery; RACA = right ACA; RCCA = right common carotid artery; RPCA = right posterior cerebral artery; RPCOM = right posterior communicating artery; RVA = right vertebral artery.

Case 2

A 60-year-old woman presented with aphasia and right-sided weakness. MRI revealed left-sided basal ganglia and watershed zone infarcts as well as prior watershed ischemic changes (Figure 2A). CTA and conventional angiography showed 95% left MCA stenosis, so the patient was placed on an aspirin and Plavix regimen. However, 1 week later she presented back to the hospital with worsening right-sided weakness and recurrence of aphasia after initial improvement from prior admission. Follow-up MRI showed new strokes (Figure 2B and C). QMRA NOVA showed low flow in the left anterior cerebral artery (ACA) and left MCA, and SPECT with Diamox showed significant left-sided hypoperfusion with diminished CVR (Figure 2D). Due to recurrence of stroke and hemodynamic compromise the patient underwent left-sided STA-MCA bypass. Postoperatively the patient experienced no complications and the graft was patent immediately and 1 year postoperatively based on QMRA NOVA (Figure 2E). At 5 years postbypass the patient had not experienced another stroke.

Figure 2.

Case 2. A: Initial MRI, DWI. B: Follow-up MRI, DWI sequence showing progression of stroke. C: Digital subtraction angiography showing severe MCA stenosis. D: Initial QMRA NOVA showing low flow in the left MCA. E: Postbypass QMRA NOVA showing patent bypass with significant flow.