The effect of leptomeningealanastomoseson hemodynamic changes of extracranial internal carotid artery in middle cerebral artery severe stenosis and occlusion disease

Objective To investigate the influence of anterior cerebral artery (ACA) leptomeningealanastomoseson the hemodynamic changes of extracranial internal carotid artery (ICA) in patients with severe stenosis and chronic occlusion of middle cerebral artery (MCA) disease. Methods One hundred and eighty six cases with severe stenosis and chronic occlusion of MCA diagnosed by transcranial color-coded sonography (TCCS) and confirmed by digital subtraction angiography (DSA) were consecutively enrolled during January 2015 to December 2015. All cases were divided into two groups, including 88 cases of severe stenosis and 98 cases with chronic occlusion. According to DSA results, there were 72 cases with leptomeningeal anastomoses (LMA) and 114 cases without LMA. Transcranial Doppler (TCD) and TCCS were performed to measure and record the peak systolic velocity (PSV), end diastolic velocity (EDV), and resistance index (RI) of bilateral ACA, color Doppler ultrasound was used to measure and record PSV, EDV and RI of bilateral ICA. The ipsilateral and contralateralhemodynamic parameters of ICA and ACA were compared betweenthe two groups by means of independent-samples t test and paired-samples t test. The difference ofhemodynamic parameters between patients with LMA and without LMA were also compared. Linear regression was used to analyze the relevance between ipsilateral ICA and ACA parameters. Results (1) The PSV and EDV of ipsilateral ICA in MCA chronic occlusion group were significantly lower than those in MCA severe stenosis group [(71.27±17.84) cm/s vs (78.07±14.69) cm/s, (27.00±8.38) cm/s vs (32.01±7.83) cm/s, 0.625±0.056 vs 0.591±0.057; t=2.820, 4.243, 4.099, all P 0.05). (2) In two groups, the PSV and EDV of ipsilateral ICA with LMA were significantly higher than those without LMA, while the RI was lower [PSV: (164.19±22.64) cm/s vs (97.56±19.17) cm/s, (168.95±28.03) cm/s vs (96.72±21.57) cm/s; EDV: (75.68±12.53) cm/s vs (42.65±10.03) cm/s, (79.93±13.73) cm/s vs (42.30±11.95) cm/s; RI: 0.540±0.036 vs 0.564±0.043, 0.526±0.037 vs 0.566±0.051; t=14.604, 14.416, 13.492, 14.444, 2.727, 4.250, all P 0.05). (3) In MCA with severestenosis group, the parameters of ipsilateral ICA between with and without LMA groupswere not significantly different (P>0.05). In MCA with chronicocclusion group, the PSV and EDV of ipsilateral ICA without LMA were significantly lower than those with LMA, and RI was higher [(65.93±13.34) cm/s vs (78.68±20.64) cm/s, (23.98±6.30) cm/s vs (31.20±9.08) cm/s, 0.638±0.055 vs 0.605±0.053; t=3.713, 4.647, 2.925, all P 0.05). In MCA with chronicocclusion group, PSV, EDV of ipsilateral ACA had positive linear correlation with PSV of ipsilateral ICA (r=0.350, 0.367, P<0.01), and had negative linear correlation with RI of ipsilateral ICA (r=-0.550, -0.531, P<0.01). Conclusions In MCA with severestenosis and chronicocclusinpatients, TCD or TCCS can be used for detecting increased velocity of ACA with LMA. The hemodynamic parameters of ipsilateral ICA could beinfluenced by LMA withdecreased velocity and increased PI when MCA was occluded, but could not be influenced by LMA when MCA was severe stenosis. Key words: Middle cerebral artery; Ultrasonography, Doppler, color; Carotid artery, internal; Hemodynamic