外分支支架和内分支支架治疗B型主动脉夹层的近期结果及计算流体力学分析

Outer branched and inner branched endografts in treatment of Stanford type B aortic dissection:short-term results and computational fluid dynamics analysis

目的:评估外分支支架和内分支支架胸主动脉腔内修复术(thoracic endovascular aortic repair, TEVAR)治疗Stanford B型主动脉夹层(Stanford type B aortic dissection, TBAD)的近期结果,并通过计算流体力学(computational fluid dynamics, CFD)分析两种支架对主动脉夹层血流状态的影响。方法:收集2018年5月至2021年12月天津医科大学总医院血管外科采用外分支支架和内分支支架治疗TBAD病人的临床资料,回顾性分析两组近期治疗结果。基于两组的CT血管造影,各选取1例典型病例构建个性化的三维模型,进行流体力学数值模拟计算。对比分析手术前、后流场速度分布、壁面压力和壁面切应力(wall shear stress, WSS)参数。结果:共纳入55例TBAD病人,其中外分支支架组49例,内分支支架组6例。两组基线资料差异无统计学意义。两组手术成功率均100%。外分支支架组41例(83.7%)和内分支支架组6例(100%)单纯重建左锁骨下动脉(left subclavical artery, LSA)。外分支支架组5例重建左颈总动脉(left common carotid artery, LCCA)联合颈锁动脉搭桥,2例重建LCCA联合LSA栓塞,1例重建LCCA联合LSA开窗。外分支支架组失访4例。两组围术期及随访期主动脉相关死亡率(P=1.000)、分支支架通畅率(P=1.000)及免于靶血管二次干预率(P=0.298)差异均无统计学意义。两组支架植入术后均显著改善夹层病变内流场紊乱,恢复正常主动脉血流形态,降低局部异常增高的WSS。内分支支架对主动脉弓部及分支血流状态的干扰较外分支明显。结论:外分支支架和内分支支架TEVAR重建LSA,治疗TBAD均有较好近期效果。外分支支架相比内分支支架解剖契合度较高,可较大程度恢复主动脉弓部正常血流状态。

Objective To evaluate the short-term outcomes of thoracic endovascular aortic repair(TEVAR) with outer branched and inner branched endografts in the treatment of Stanford type B aortic dissection(TBAD),and to analyze the effects of endografts on blood flow status of aortic dissection by computational fluid dynamics(CFD).Methods The clinical data of TBAD patients treated with outer branched endograft technology in outer branched endograft group and inner branched endograft technology in inner branched endograft group in Department of Vascular Surgery Tianjin Medical University General Hospital from May 2018 to December 2021 were collected,and the short-term results of two groups were analyzed retrospectively.Based on CT angiography images of patients in two groups,one typical case in each group was selected to construct personalized 3D model and CFD numerical simulation was performed.The parameters including flow field velocity distribution,wall pressure and wall shear stress(WSS) before and after surgery were compared and analyzed.Results A total of 55 cases with TBAD were enrolled,consisting of 49 cased in outer branched endograft group and 6 cases in inner branched endograft group.There was no statistical difference in baseline data between two groups,and surgical success rate were both 100%.Reconstruction of left subclavical artery(LSA) simple was 41(83.7%) cases in outer branched endograft group and all 6 cases in inner branched endograft group.In outer branched endograft group there were 5 cases with reconstruction of left common carotid artery(LCCA) combined with bridging carotic clavical artery,2 cases with reconstruction of LCCA combined with LSA embolism,and 1 case with reconstruction of LCCA combined with LSA window.Four cases were lost during follow-up in outer branched endograft group.There were no significant differences in the aorta-related mortality rate(P=1.000),branch patency rate(P=1.000) and avoidance of secondary intervention of target vessels between the two groups during the perioperative period and follow-up period(P=0.298).After endograft implantation of two groups the flow field disturbance in dissection lesions improved significantly,aortic blood flow pattern restored normal,and local abnormally increased WSS decreased.However,the interference of inner branch on aortic arch and blood flow of branch was more obvious than that of outer branch.Conclusions Both outer branched endograft and inner branched endograft TEVAR for reconstruction of LSA had good short-term results in the treatment of TBAD.Compared with inner branched endograft,outer branched endograft has a higher anatomical fit and can restore the normal blood flow to a greater extent for aortic arch.