Quantitative Analysis of Haemodynamic Influences on Cerebral Circulation in Hybrid Thoracic Endovascular Aortic Repair: A Prospective Study.

Abstract

This study aimed to use quantitative magnetic resonance angiography (qMRA) to investigate the haemodynamic influences on cerebral circulation after hybrid thoracic endovascular aortic repair (TEVAR). Between January 2016 and October 2019, zone 1 and 2 TEVAR with supra-arch extra-anatomical rerouting procedures were performed in 24 patients (mean age 72.9 ± 11.7 years) and hybrid total arch replacement (TAR) was performed in eight patients (mean age 72.0 ± 8.5 years), all of whom underwent qMRA before and after the procedure. Degenerative and dissected aneurysms were observed in 23 and nine cases, respectively. Blood flow in the internal carotid artery (ICA) and vertebral artery (VA) was measured using qMRA. The anterior and posterior cerebral circulation flows were defined as the sum of the bilateral ICA and VA flows, respectively. Total intracranial blood flow (TICF) was defined as the sum of anterior and posterior cerebral circulation flows. The pre- and post-operative values of these parameters were compared for each procedure. Zone 1 and 2 TEVAR caused no significant post-operative differences in TICF or anterior and posterior cerebral circulation. The right VA flow increased significantly after zone 1 and 2 TEVAR (median [interquartile range] 68.0 mL/min [36.8, 95.5] vs. 110.5 mL/min [76.0, 159.5] mL/min; p < .001), whereas the left VA flow decreased significantly (median [interquartile range] 92.0 mL/min [60.3, 107.0] vs. 39.0 mL/min [19.3, 81.0]; p < .001). The post-operative ICA flow was maintained at the pre-operative level after all procedures. The hybrid TAR group showed no significant post-operative differences in TICF or anterior and posterior cerebral circulation. The post-operative distribution of each branch flow was also not significantly different from the pre-operative distribution. Although VA flow showed a disproportionate distribution in the posterior circulation after zone 1 and 2 TEVAR, TICF remained comparable with the pre-operative level after both zone 1 and 2 TEVAR and TAR.