Quantitative evaluation of blood flow in each cerebral branch associated with zone 1-2 thoracic endovascular aortic repair

Abstract

Objectives: Optimal methods to quantitatively evaluate the blood flow in each cerebral artery after zone 1 2 thoracic endovascular aortic repair (TEVAR) remain unknown. Our objective was to evaluate the differences between preoperative and postoperative cerebral artery blood flows after zone 1 2 debranching TEVAR (dTEVAR). Between January 2016 and August 2018, a prospective analysis of the blood flow in both the internal carotid artery and the vertebral artery in 16 patients before and after zone 1 2 dTEVAR was conducted. Zone 1 dTEVAR with right axillary artery left common carotid artery left axillary artery (RAxA-LCCA-LAxA) bypass was performed on 7 patients. Zone 2 dTEVAR was performed on 9 patients: 4 underwent RAxA-LAxA bypass and 5 underwent LCCA-LAxA bypass. Quantitative magnetic resonance angiography was performed before and after zone 1 2 dTEVAR. Total intracranial blood flow was preserved postoperatively [The median (interquartile range) preoperatively vs postoperatively: 621 (549 686) vs 638 (539 703) ml/min, not significant]. The anterior [469 (400 504) vs 475 (404 510) ml/min, not significant] and posterior cerebral blood flows [157 (121 199) vs 163 (123 210) ml/min, not significant] were also maintained postoperatively. In the 3 debranching procedures, the postoperative anterior and posterior cerebral blood flows were maintained at rates similar to preoperative rates, with the proportion of anterior and posterior cerebral circulations reaching almost 75% and 25%, respectively. No significant differences between preoperative and postoperative distributions of internal carotid artery blood flows were observed. Regarding vertebral artery blood flows, the distribution of blood flow through the left vertebral artery was significantly lower postoperatively than preoperatively; however, the postoperative right vertebral artery blood flow distribution significantly increased compared with the preoperative flow. In zone 1 2 dTEVAR, total intracranial blood flow was preserved postoperatively, and the postoperative anterior and posterior cerebral circulations were maintained at rates similar to their preoperative rates..