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：主动脉瓣/人工瓣膜心内膜炎（aortic/prosthetic valve endocarditis）患者属于高危患者人群，对所有相关医学学科均构成临床挑战，且可通过多种外科技术实施治疗。
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®）行全根部置换术治疗根部心内膜炎的临床疗效，并与其他组织瓣膜治疗方案进行对比。本研究采用倾向得分匹配（propensity score matching）结合近邻法（nearest neighbor method）进行病例配对，并根据分析需求开展各项检验。
结果：最终美敦力Freestyle®组（FS组）的54例患者与接受其他组织瓣膜治疗的54例复杂性根部心内膜炎患者（组织瓣膜组）完成配对。FS组住院死亡率为9/54（16.7%），组织瓣膜组为14/54（25.6%）（P=0.24）。针对早期临床结局的Cox回归（Cox regression）分析显示，冠心病（P=0.004，比值比（odds ratio）=2.3）等因素可影响早期死亡率。两组复发性感染发生率均较低（FS组与组织瓣膜组均为1.8%）；在总计367患者年的随访周期中（中位随访时间2.7年），无再手术生存率达97.2%。
结论：无支架异种瓣膜移植物（stentless xenograft）是治疗瓣膜/根部/人工瓣膜心内膜炎的可行方案，其复发性感染率较低。该生物瓣根部的结构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。通过清除血流中的感染组织对心内膜炎患者进行治疗，或可改善菌血症及复发性感染的相关预后。此外，若未来出现瓣膜退变，使用无支架生物瓣根部可提供多样化的治疗选择。