The potential causes of abnormal hemodynamical changes after stenting in selected patients with symptomatic middle cerebral artery stenosis

Objective To analyze the potential causes of abnormal hemodynamic changes after stenting in se- lected patients with symptomatic middle cerebral artery(MCA)stenosis.Methods Patients with symptomatic MCA stenosis underwent MCA stenting if they had recurred symptoms of cerebral ischemia while receiving an- tiplatelet therapy.Transcranial Doppler(TCD)examination was performed before and 3 days after stenting.The causes of abnormal hemodynamics were analyzed by TCD spectra,clinical symptoms and neuroimaging.Results Among the 29 patients(31 stenotic MCA),TCD spectra in 27 MCA restored to nearly normal level after stenting. The stenosis-like spectra at stenotic segment appeared in four patients(four MCA)within 3 days after stenting and 2 patients occurred intracranial hemorrhagic changes on CT scans.The potential causes were hyperperfusion syn- drome with 3 patients,and another severe stenosis was found at down branch of MCA in 1 patient.Conclusion The potential causes may be hyperperfusion syndrome or phenomenon and stenosis of other branch of MCA in pa- tients with stenosis removing on angiography but stenosis-like spectra on TCD after stenting.