Background Hyperperfusion syndrome after carotid interventions has a low incidence but it can lead to morbidity and mortality.

Objective To evaluate the usefulness of quantitative DSA for predicting hyperperfusion phenomenon (HPP) after carotid artery stenting and angioplasty.

Methods Thirty-three consecutive patients with carotid stenosis treated with carotid artery stenting or angioplasty between February 2014 and August 2016 were included. Color-coded digital subtraction angiograms showing the time to maximum contrast intensity of each image pixel were obtained from conventional DSA before and after procedures. The cerebral circulation time (CCT) was defined as the difference in the relative time to maximum intensity between arterial and venous regions of interest set on the angiograms. HPP was diagnosed straight after the procedure with qualitative ¹²³I-IMP single-photon emission CT (SPECT). Cut-off points for detecting HPP for preprocedural CCT and periprocedural change of CCT were assessed by receiver operating characteristic analysis using ¹²³I-IMP SPECT as reference standard.

Results ¹²³I-IMP SPECT showed HPP in 4 of 33 patients. In these 4 patients, preprocedural prolongation of CCT (13.0±6.1 vs 7.2±1.3 s; p<0.001) was seen compared with patients without HPP as well as larger periprocedural changes of CCT (5.9±5.7 vs 0.5±1.3 s; p<0.001). The optimal cut-off points of preprocedural CCT and change of CCT for predicting HPP were 8.0 s (100% sensitivity, 69% specificity) and 3.2 s (75% sensitivity, 100% specificity), respectively.

Conclusions Preprocedural prolongation and greater periprocedural change of CCT are associated with the occurrence of HPP. Periprocedural evaluation of CCT may be useful for predicting HPP.