Stentless Root Replacement versus Tissue Valves in Infective Endocarditis - A Propensity-Score Matched Study

Abstract Introduction: People with aortic/prosthetic valve endocarditis are a high-risk cohort of patients who present a challenge for all medically involved disciplines and who can be treated by various surgical techniques. Methods: We analyzed the results of treatment of root endocarditis with Medtronic Freestyle® in full-root technique over 19 years (1999-2018) and compared them against treatment with other tissue valves. Comparison was made with propensity score matching, using the nearest neighbor method. Various tests were performed as suited for adequate analyses. Results: Fifty-four patients in the Medtronic Freestyle group (FS group) were matched against 54 complex root endocarditis patients treated with other tissue valves (Tissue group). Hospital mortality was 9/54 (16.7%) in the FS group vs. 14/54 (25.6%) in the Tissue group (P=0.24). Cox regression performed for early results demonstrated coronary heart disease (P=0.004, odds ratio 2.3), among others, influencing early mortality. Recurrent infection was low (1.8% for FS and Tissue patients) and freedom from reoperation was 97.2% at a total of 367 patient-years of follow-up (median of 2.7 years). Conclusion: The stentless xenograft is a viable alternative for treatment of valve/root/prosthetic endocarditis, demonstrating a low rate of reinfection. The design of the bioroot allows for complex reconstructive procedures at the outflow tract and the annular level with at an acceptable operative risk. Endocarditis patients can be treated excluding infective tissue from the bloodstream, possibly with benefits, concerning bacteremia and recurrent infection. Furthermore, the use of the stentless bioroot offers varying treatment options in case of future valve degeneration.

摘要
引言：主动脉瓣/人工瓣膜心内膜炎患者属于高危患者群体，对所有涉医学科均构成诊疗挑战，此类患者可通过多种外科技术开展治疗。
方法：本研究分析了1999年至2018年共19年间，采用美敦力Freestyle®（Medtronic Freestyle®）全根技术治疗根部心内膜炎的疗效，并与其他生物瓣膜治疗方案进行对比。对比采用倾向得分匹配法，以近邻法完成匹配，并开展适配的各类分析以确保分析严谨充分。
结果：本研究共匹配得到美敦力Freestyle组（FS组）患者54例，以及采用其他生物瓣膜治疗的复杂根部心内膜炎患者54例（生物瓣膜组）。FS组院内死亡率为9/54（16.7%），生物瓣膜组为14/54（25.6%）（P=0.24）。针对早期结局的Cox回归分析显示，除其他因素外，冠心病（P=0.004，优势比2.3）对早期死亡率存在显著影响。两组患者的复发感染率均较低（FS组与生物瓣膜组均为1.8%），在总计367患者-年的随访（中位随访时长2.7年）中，免于再次手术率为97.2%。
结论：无支架异种移植物可作为瓣膜/根部/人工瓣膜心内膜炎的可行治疗方案，其再感染率较低。该生物根部的设计可在流出道及瓣环水平开展复杂重建手术，且手术风险可接受。心内膜炎患者可通过切除血流中受感染组织进行治疗，这或可改善菌血症及复发感染的预后。此外，若未来出现瓣膜退变，使用无支架生物根部可为后续治疗提供多样化选择。