自膨胀瓣膜植入深度的解剖学影响因素及临床结局分析:一项回顾性队列研究

Anatomic influencing factors on implantation depth of self-expandable valve and its short-term clinical outcome: a retrospective cohort study of 54 cases

目的探讨经导管主动脉瓣置换术(transcatheter aortic valve replacement,TAVR)中自膨胀瓣膜植入深度的解剖形态影响因素,并分析瓣膜植入深度对短期临床预后的影响。方法回顾性分析2017年10月至2020年5月在本院行TAVR术的主动脉瓣重度狭窄患者病历资料。测算主动脉根部解剖径线及其与植入瓣膜支架尺寸的比例,并测定瓣膜植入深度。比较瓣膜植入过深组[植入深度超过最高四分位数(>14.8 mm)]与瓣膜位置合适组(植入深度≤14.8 mm)的解剖结构差异,分析瓣膜植入深度对血流动力学、传导阻滞等临床预后的影响。结果 54例主动脉瓣重度狭窄患者被纳入分析,其中二叶瓣21例,三叶瓣33例,瓣膜植入深度0~21 mm,中位数为11.6 mm。二叶瓣人群中植入过深组的窦管结合部平均直径大于位置合适组[(36.06±2.29) mm vs(29.69±2.55) mm,P=0.001];在三叶瓣人群中植入过深组的29号瓣膜的植入比例更高(100.0%vs 26.9%,P=0.025),流出道长径与植入瓣膜底径的比值更小(0.99±0.03 vs 1.12±0.15,P=0.021)。位置合适组和植入过深组的术后死亡率相当(4.88%vs 15.38%,P=0.242),但植入过深组转外科开胸手术的比例有高于位置合适组的趋势(15.4%vs 0%,P=0.055)。术后1周,两组的主动脉瓣跨瓣压差、峰值流速、起搏器植入率、主动脉瓣周中度以上反流、新发完全性左束支传导阻滞发生率差异无统计学意义(P>0.05)。术后1个月植入过深组新发完全性左束支传导阻滞(50.0%vs 13.3%,P=0.044)及主动脉瓣周中度以上反流(33.3%vs 0%,P=0.009)的发生率均高于位置合适组。植入过深组的早期安全性低于位置合适组(69.2%vs 95.1%,P=0.025)。结论主动脉根部解剖结构及其与植入瓣膜的尺寸比例对自膨胀瓣膜的植入深度有一定影响,窦管结合部直径较大的二叶瓣患者或植入大号瓣膜的三叶瓣患者中容易植入过深。瓣膜植入过深会增加术后1个月新发完全性左束支传导阻滞及瓣周反流的风险,并影响早期安全性。

Objective To investigate the anatomic factors influencing the implantation depth(ID) of self-expandable valve during transcatheter aortic valve replacement(TAVR) surgery, and to analyze the impact of ID on the short-term clinical prognosis. Methods Clinical data of 54 patients with severe aortic stenosis who underwent TAVR in our hospital from October 2017 to May 2020 were collected and retrospectively analyzed. The anatomic diameter of aortic root and its ratio to the implanted valve size was measured and calculated, and the depth of the valve implanted was also measured. The patients were assigned into either over-implanted group(>14.8 mm, the highest quartile of ID) or well-implanted group(≤14.8 mm) based on the ID of their valve. The differentiation of anatomical structures was compared between the 2 groups. Additionally, the impacts of ID on the clinical outcomes such as hemodynamics and conduction block were analyzed. Results There were 21 cases of bicuspid aortic valve(BAV) and 33 cases of tricuspid aortic valve(TAV), and the ID of valve was 0~21 mm, with a median of 11.6 mm. Among the BAV patients, the average diameter of sinotubular junction(STJ) was significantly larger in the over-implanted group than the well-implanted group(36.06±2.29 vs 29.69±2.55 mm, P=0.001). As for the TAV patients, the over-implanted group had a higher proportion of large prosthesis implantation(100.0% vs 26.9%, P=0.025), and a smaller ratio of the length of the left ventricular output tract to the bottom diameter of the valve(0.99±0.03 vs 1.12±0.15, P=0.021) when compared with the well-implanted group. Postoperative mortality was comparable between the 2 groups(4.88% vs 15.38%, P=0.242). However, the incidence of being converted to open surgery was higher in the over-implanted group than the other group(15.4% vs 0%, P=0.055). In 1 week after TAVR, there were no statistical differences in the mean aortic valve gradient, maximum velocity, permanent pacemaker implantation rate, moderate or severe paravalvular leakage, or new-onset left bundle branch block(LBBB) between the 2 groups(P>0.05), whereas the incidence of new-onset LBBB(50.0% vs 13.3%, P=0.044) and paravalvular leakage(33.3% vs 0%, P=0.009) were higher in the over-implanted group on the 30 th day. The early safety was inferior in the over-implanted group(69.2% vs 95.1%, P=0.025). Conclusion The anatomical structure of the aortic root and its ratio to the size of the implanted valve have a certain effect on the implantation depth of self-expandable prosthesis. The BAVs patients with greater STJ as well as those TAVs patients treated with larger size valve may be both correlated with increased risks of deep implantation. Over implantation of the valve may increase the risk of new-onset LBBB and moderate or severe paravalvular leakage in 1 month after operation, and thus compromise the early safety.