Department of Cardiac, Thoracic and Vascular Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
Department of Cardiac, Thoracic and Vascular Surgery, Yong Loo Lin School of Medicine, National University of Singapore, Singapore.
J Surg Res. 2019 Feb;234:249-261. doi: 10.1016/j.jss.2018.09.019. Epub 2018 Oct 12.
Experimental surgical procedures for atrioventricular valves present promising translational capabilities, and preclinical studies are necessary to assess their applicability and to train young enthusiastic heart teams. Here, we present a synopsis of experimental surgical procedures on porcine models for mitral valvular (MV) and tricuspid valvular (TV) interventions; mitral valve-in-valve implantation (MViV), transapical cardioscopic (TAC) MV replacement (MVR), TAC-MV annuloplasty, and tricuspid valve-in-a-ring (TViR) procedures.
Twenty-five (n = 25) female Yorkshire pigs of 55-65 kg is the total number used in the four approaches; seven animals underwent MViV, six TAC-MVR, six TAC-MV annuloplasty, and six TViR, respectively. All were subjected to a first conventional valvular surgery (bioprosthetic valve replacement and/or prosthetic ring repair). Then, after 4 wk, a less-invasive second surgery was performed using the transcatheter approaches under investigation. Except for the TAC-MVR and annuloplasty procedures, all animals were followed up for additional 4 wk.
(1) MViV (n = 7): Standard MVR was successfully performed in all animals. Transvalvular pressure gradients and flow velocities were (P 3.77 ± 0.8 mmHg; P 2.1 ± 0.6 mmHg, V 97 ± 13 cm/s; V 68 ± 21 cm/s). Effective MViV followed (P 16.7 ± 1.8 mmHg; P 6.2 ± 1.2 mmHg, V 216 ± 32 cm/s; V 110 ± 24 cm/s). (2) TAC-MVR (n = 6): The overall bypass time was 177.2 ± 44.2 min. Transprosthetic P was 4.6 ± 2.4 mmHg; no paravalvular leaks in all animals. (3) TAC-MV annuloplasty (n = 6): The implantation time was 47 ± 6 min. MV was competent, left ventricular ejection fraction (LV-EF%) was 63 ± 4%. (4) TViR (n = 6): Conventional TV ring repair was performed in all animals (P 2.42 ± 0.7 mmHg; P 1.3 ± 0.6 mmHg, V 82 ± 10.4 cm/s; V 65.4 ± 21 cm/s). All TViRs were implanted efficiently (P 4.7 ± 1.6 mmHg; P 2.7 ± 0.8 mmHg, V 105 ± 31 cm/s; V 81 ± 16 cm/s). A mild paravalvular leak was observed in one animal (16%).
All studied experimental valvular interventions are feasible, within the context of well-trained cardiac surgery specialists, and all possibilities should be considered when treating a patient to determine which one suits best his individual challenges and scope.
房室瓣的实验性外科手术具有很有前景的转化能力，有必要进行临床前研究来评估其适用性，并培训年轻热情的心脏团队。在这里，我们总结了在猪模型上进行二尖瓣（MV）和三尖瓣（TV）介入的实验性外科手术；二尖瓣瓣中瓣植入术（MViV）、经心尖心腔镜（TAC）二尖瓣置换术（MVR）、TAC-MV 瓣环成形术和三尖瓣环中瓣术（TViR）。
共使用 25 只（n=25）55-65 公斤的雌性约克夏猪进行这四种方法；7 只动物接受了 MViV，6 只动物接受了 TAC-MVR，6 只动物接受了 TAC-MV 瓣环成形术，6 只动物接受了 TViR。所有动物均首先进行常规瓣膜手术（生物瓣置换和/或瓣环修复）。然后，在 4 周后，使用正在研究的经导管方法进行微创二次手术。除了 TAC-MVR 和瓣环成形术，所有动物均再随访 4 周。
（1）MViV（n=7）：所有动物均成功完成标准 MVR。跨瓣压差和流速分别为（P 3.77±0.8mmHg；P 2.1±0.6mmHg，V 97±13cm/s；V 68±21cm/s）。随后进行了有效的 MViV（P 16.7±1.8mmHg；P 6.2±1.2mmHg，V 216±32cm/s；V 110±24cm/s）。（2）TAC-MVR（n=6）：总的旁路时间为 177.2±44.2 分钟。经瓣口压力为 4.6±2.4mmHg；所有动物均无瓣周漏。（3）TAC-MV 瓣环成形术（n=6）：植入时间为 47±6 分钟。MV 功能良好，左心室射血分数（LV-EF%）为 63±4%。（4）TViR（n=6）：所有动物均进行了常规的 TV 环修复（P 2.42±0.7mmHg；P 1.3±0.6mmHg，V 82±10.4cm/s；V 65.4±21cm/s）。所有 TViR 均有效植入（P 4.7±1.6mmHg；P 2.7±0.8mmHg，V 105±31cm/s；V 81±16cm/s）。一只动物（16%）观察到轻度瓣周漏。
所有研究的实验性瓣膜介入术在训练有素的心脏外科专家的情况下是可行的，在治疗患者时应考虑所有可能性，以确定哪种方法最适合他的个体挑战和范围。
