Diagnosis of cerebral vasospasm and risk of delayed cerebral ischemia related to aneurysmal subarachnoid haemorrhage: an overview of available tools.

In the first weeks following aneurysmal subarachnoid haemorrhage, cerebrovascular alterations may impact the outcome significantly. Diagnosis of cerebral vasospasm and detection of alterations at risk of delayed cerebral ischemia are key targets to be monitored in the post-acute phase. Available tools include clinical monitoring, as well as studies that can detect possible arterial narrowing, alterations of perfusion, metabolism and neurophysiology. Each technique is able to investigate possible vascular impairment and has different advantages and limits. All available techniques have been described. Among these, the most practical have been selected and compared for their peculiar characteristics. Based on this analysis, a flowchart to monitor these patients is finally proposed.

The Eligible study: ultrasound assessment in acute ischemic stroke within 3 hours.

AIMS OF THE STUDY: to identify with echo color Doppler ultrasound of the supra-aortic vessels and transcranial color-coded duplex sonography (TCCD) various patterns of vessel occlusion within 3 h from stroke onset, to compare each group defined at the admission with clinical findings and outcome, and to study the recanalization process, independent of therapy. METHODS: We enrolled 89 consecutive patients (mean age 68.9 years). Ultrasound evaluation was done within 3 h from stroke onset, and was repeated at 3-6 and 24-36 h, at day 5, and at 3 months. At admission, patients were divided into the following groups: internal carotid artery occlusions and stenoses (<50%, 50-69%, > or =70%, near occlusion), middle cerebral artery stenoses and occlusions, tandem occlusions and T occlusions. Vascular recanalization in each group was evaluated. Subgroups were compared for NIH Stroke Scale (NIHSS) and the outcome measures mortality, Barthel index (BI) and modified Rankin scale (mRS). Favorable outcome was defined as mRS < or =2 and BI > or =90. RESULTS: Each subgroup differed significantly for baseline NIHSS (p < 0.0001), 3-month mortality (p = 0.0235), BI at day 5 (p = 0.0458) and mRS at 3 months (p = 0.0028), even after adjustment for treatment. T and tandem occlusions were the subgroups with the highest NIHSS scores and the poorest outcomes, and the same subgroups had the worst recanalization rates. CONCLUSIONS: TCCD in the acute setting of stroke patients allows identification of the presence and site of clots, prediction of outcome and study of the dynamic process of vessel recanalization, in both the acute phase and follow-up.

Transcranial Doppler monitoring during stenting of the carotid bifurcation: evaluation of two different distal protection devices in preventing embolization.

PURPOSE: To compare the efficacy of 2 emboli protection devices in preventing embolization during carotid artery stenting (CAS). METHODS: The GuardWire distal occlusion system (n=19) and the distal FilterWire EX (n=12) were compared in 31 consecutive patients (24 men; mean age 71+/-10 years) monitored with transcranial Doppler for microembolic signals before, during, and after CAS. The choice of the protection device was based on availability and on the patency of the contralateral carotid artery. RESULTS: The baseline characteristics were similar in the patients treated under protection from either device. Placement and retrieval of the protection device, stenting, and postdilation were technically successful in all patients. Two patients suffered a transient ischemic attack shortly after the procedure; no other adverse cardiovascular events occurred at 30 days. Compared to the GuardWire, the use of the FilterWire was associated with more microembolic signals during stent deployment (77.4+/-33.5 versus 1.07+/-1.94, p<0.0001), postdilation (63.9+/-21.0 versus 2.06+/-2.58, p<0.0001), and retrieval of the protection device (21.4+/-15.4 versus 10.9+/-8.3, p=0.051). Consequently, the total amount of microembolic signals during the procedure was higher when the filter device was employed (183.0+/-42.1 versus 31.7+/-12.0, p<0.0001). CONCLUSION: The distal occlusion device appears to be more effective than the filter in reducing distal embolization detected by transcranial Doppler monitoring.