Prediction of hyperperfusion after carotid artery stenting based on preoperative estimation of the cerebral blood flow (according to the Kuroda grading system) by single photon emission computed tomography

Abstract

This study was conducted to investigate whether preoperative estimation of the cerebral blood flow (CBF) by single photon emission computed tomography (SPECT) can allow identification of patients at risk for hyperperfusion (HP) after carotid artery stenting (CAS). In 40 patients scheduled to undergo CAS, the CBF and cerebral vascular reserve (CVR) were measured prior to the intervention by resting and acetazolamide loading SPECT. The SPECT findings were classified into 4 types: Type 1, normal CBF in the resting state (CBFrest) and normal CVR; Type 2, normal CBFrest and reduced CVR; Type 3, reduced CBFrest and reduced CVR; and Type 4, reduced CBFrest and normal CVR. Four patients presented with HP after CAS. Patients with high proportions of Type 2 and Type 3 had high risk of HP after CAS. (ROC analysis: AUC=0.94, cutoff value of 75.8% had PPV of 75.0%, NPV of 97.2% and odds ratio of 105.0). The proportions of Type 2 and Type 3 in preoperative SPECT may identify patients at risk for the development of HP.