Combination of transcranial Doppler and end-tidal carbon dioxide partial pressure in evaluating cerebrovascular reserve of patients with intracranial angiostegnosis

The study aims to apply the combination of transcranial Doppler (TCD) and end-tidal carbon dioxide partial pressure (ETCO2) for evaluating the cerebrovascular reserve (CVR) in the patients with intracranial angiostegnosis. 42 CVR patients, who were confirmed by TCD and (or) digital subtraction arteriography (DSA) as the unilateral or bilateral middle cerebral artery stenosis and (or) combined with other intracranial, exterior main artery stenosis, were collected. Another 30 cases were set as the control group. The included patients were monitored ETCO2 by TCD and QL software. The methods of inhaling the autologous CO2 gas, as well as the hyperventilation, were used to measure CVR by inducing the hypercapnia and hypocapnia, respectively. We found that the expansion reserve of the severer side in the multiple vascular stenosis group was significantly lower than the normal group (P<0.05). The overall CVR of the severer side in the multiple vascular stenosis group was significantly lower than the diseased side in the lateral artery stenosis group (P<0.05). The vascular lesion degrees were negatively correlated with the vasodilator reserve values and the overall reserve values of the severer side (P<0.05). The more severe the intracranial angiostegnosis, the worse CVR. In conclusion, the combination of TCD and ETCO2 could be effectively used in the evaluation and research of CVR.