Multichannel near-infrared spectroscopy as a tool for assisting intra-arterial fasudil therapy for diffuse vasospasm after subarachnoid hemorrhage

Abstract

Background: Diffuse cerebral vasospasm following aneurysmal subarachnoid hemorrhage (SAH) refractory to medical management can be treated with intra-arterial administration of vasodilators, but valid bedside monitoring for the diagnosis and therapeutic assessment is poorly available. We demonstrate the successful application of regional cerebral oxygen saturation (rSO(2)) monitoring with multichannel near-infrared spectroscopy (NIRS) in assisting intra-arterial infusions of fasudil hydrochloride to a patient suffering from post-SAH vasospasm in the distal vascular territories.

Case description: A 63-year-old man presented with SAH and intracerebral hematoma due to ruptured right middle cerebral artery aneurysm developed aphasia and right-sided weakness on day 9 after SAH onset. Delayed cerebral ischemia attributable to diffuse vasospasm in the distal territories of the left anterior and middle cerebral arteries was suspected. Since the symptoms persisted despite maximal hyperdynamic therapy with dobutamine, intra-arterial fasudil treatment in the setting of rSO(2) monitoring including the spasm-affected vascular territory with four-channel flexible NIRS sensors was subsequently performed. Decreased and fluctuating rSO(2) in angiographically documented vasospastic territories increased immediately after intra-arterial fasudil infusion in accordance with relief of vasospasm that correlated with neurological improvement. The procedure was repeated on day 11 since the effect was transient and neurological deterioration and reduction of rSO(2) recurred. The deficits resolved accompanied by uptake and maintenance of rSO (2) following the intra-arterial fasudil, resulting in favorable functional outcome.

Conclusion: Continuous rSO(2) monitoring with multichannel NIRS is a feasible strategy to assist intraarterial fasudil therapy for detecting and treating the focal ischemic area exposed to diffuse vasospasm.

Keywords: Fasudil hydrochloride; intra-arterial infusion; near-infrared spectroscopy; subarachnoid hemorrhage; vasospasm.

Figure 1

(a) CT scans showing SAH combined with a massive right temporal intracerebral hematoma. (b) Preoperative 3-dimensional CT angiography showing bilateral MCA aneurysms. Ruptured aneurysm on the right side (arrow) was successfully clipped (inset). Clinical deterioration attributable to vasospasm was suspected based on findings of no apparent ischemic lesion on diffusion-weighted MR images (c) and relatively decreased rCBF in the left ACA and MCA territories on Tc-99 m HMPAO SPECT (d)

Figure 2

(a) Left internal carotid artery angiogram demonstrates diffuse angiographic vasospasm. (b) Intra-arterial fasudil infusion from the top of internal carotid artery (arrow) and subsequent selective infusion from distal portion of M1 (c, arrow), resulting in significant reversal of vasospasm (d). Low and fluctuating rSO₂ detected in the left ACA territory (E, Ch-1) increased immediately after each fasudil infusion, while rSO₂ in the MCA territory (F, Ch-3) gradually elevated following infusion from the distal M1 segment. Each yellow bar represents intra-arterial fasudil infusion

Figure 3

Diffusion-weighted MR images (a) and SPECT (b) showing new small infarctions and decreased rCBF in the left ACA--MCA territory. (c) DSA showing moderate vasospasm of distal A1 and diffuse vasospasm in the distal ACA and MCA branches. (d) Intra-arterial fasudil infusions resulted in an improvement of the distal vasospasm and cerebral circulation time (inset). Low and fluctuating rSO₂ detected in the left ACA--MCA territories increased immediately after each infusion and recovered close to the contralateral recordings (e, Ch-1). Each yellow bar represents intra-arterial fasudil infusion

Figure 4

(a) Follow-up MR angiography on day 14 showing improvement of vasospasm. (b) Diffusion-weighted MR images demonstrated no additional ischemic findings after repeated endovascular therapy. (c) Tc-99 m HMPAO SPECT confirmed normalized rCBF distribution in the left hemisphere. (d) CT scan at 2 months after SAH showing no apparent ischemia in the left hemisphere