Hemodynamic assessment of intracranial atherosclerotic stenosis using angiographic images: correlation with in-stent restenosis

BACKGROUND AND PURPOSE: Cerebral hemodynamics hold profound clinical significance in the comprehensive management of intracranial atherosclerotic stenosis (ICAS). We have developed Angio-FF—a novel non-invasive fractional flow (FF) calculation technique derived from cerebral angiography, for evaluating hemodynamics in patients with ICAS. This study aims to evaluate the clinical applicability of Angio-FF in reflecting cerebral hemodynamics by assessing its correlation with in-stent restenosis (ISR) in ICAS patients.

MATERIALS AND METHODS: A total of 54 patients with severe ICAS who had undergone cerebral angiography were recruited in the study between January 2019 and September 2022. For each patient, both preoperative and immediate postoperative Angio-FF values were collected and compared. During the 6-month follow-up, 9 patients were confirmed to have developed ISR. Receiver-operating characteristic curve (ROC) analysis was performed to evaluate the predictive efficacy of immediate postoperative Angio-FF value in differentiating between ISR and non-ISR.

RESULTS: No statistically significant disparities were detected in pre-operative morphological and hemodynamic between ISR and non-ISR groups. However, the immediately postoperative degree of stenosis (DS)% was significantly different between the ISR and non-ISR groups [26 (22-33) vs. 10 (0-20), P<0.001]. The postoperative Angio-FF value in the ISR group was markedly lower than that in the non-ISR group [0.84 (0.81-0.90) vs. 0.94 (0.87-0.97), P=0.007]. ROC analysis was performed to assess the predictive value of postoperative Angio-FF for ISR (AUC=0.785, 95%CI 0.647 to 0.923), with a cut-off value of 0.845.

CONCLUSIONS: This study reveals that immediately postoperative Angio-FF is an effective predictor of ISR, providing valuable intraoperative information for assessing the effectiveness of stenting in patients with ICAS.

ABBREVIATIONS: DS = degree of stenosis; EVT = endovascular treatment; FF = fractional flow; ICAS = intracranial atherosclerotic stenosis; ISR = in-stent restenosis; PTAS = percutaneous transluminal angioplasty and stenting; TIMI = Thrombolysis in Myocardial Infarction.