Abstract：
Pulmonary valve (PV) monocusp reconstruction in transannular patch (TAP) right ventricular outflow tract (RVOT) repair for Tetralogy of Fallot has variable clinical outcomes across different surgical approaches. The study purpose was to systematically evaluate how monocusp leaflet design parameters affect valve function in-vitro.
A 3D-printed, disease-specific RVOT model was tested under three infant physiological conditions. Monocusps were sewn into models with the native main pulmonary artery (MPA) forming backwalls that constituted 40% and 50% of the reconstructed circumference for z-score zero PV annulus and MPA diameters (native PV z-score - 3.52 and - 2.99 for BSA 0.32m2). Various leaflet free edge lengths (FEL) (relative to backwall), positions (relative to PV STJ), and scallop depths were investigated across both models. Pressure gradient, regurgitation, and coaptation were analyzed with descriptive statistics and regression models.
Increasing FEL beyond 100% of the MPA backwall decreased gradient but mildly increased regurgitation to a peak of 25%. Positioning the free edge 2 mm past the STJ mildly increased gradient for each FEL without significantly changing regurgitation compared to STJ placement. Scalloping leaflets trivially affected performance. Pre-folding leaflets improved mobility and slightly reduced gradient.
Balancing gradient, regurgitation, and oversizing for growth, a set of leaflet designs have been selected for pre-clinical evaluation. Designs with leaflet widths 140-160% in the 40% backwall model (110-120% in the 50% backwall), positioned at or 2 mm past the STJ, demonstrated the best results. The next stage of ex-vivo testing will additionally consider native RVOT distensibility, native leaflet interactions, and TAP characteristics.
A 3D-printed, disease-specific RVOT model was tested under three infant physiological conditions. Monocusps were sewn into models with the native main pulmonary artery (MPA) forming backwalls that constituted 40% and 50% of the reconstructed circumference for z-score zero PV annulus and MPA diameters (native PV z-score - 3.52 and - 2.99 for BSA 0.32m2). Various leaflet free edge lengths (FEL) (relative to backwall), positions (relative to PV STJ), and scallop depths were investigated across both models. Pressure gradient, regurgitation, and coaptation were analyzed with descriptive statistics and regression models.
Increasing FEL beyond 100% of the MPA backwall decreased gradient but mildly increased regurgitation to a peak of 25%. Positioning the free edge 2 mm past the STJ mildly increased gradient for each FEL without significantly changing regurgitation compared to STJ placement. Scalloping leaflets trivially affected performance. Pre-folding leaflets improved mobility and slightly reduced gradient.
Balancing gradient, regurgitation, and oversizing for growth, a set of leaflet designs have been selected for pre-clinical evaluation. Designs with leaflet widths 140-160% in the 40% backwall model (110-120% in the 50% backwall), positioned at or 2 mm past the STJ, demonstrated the best results. The next stage of ex-vivo testing will additionally consider native RVOT distensibility, native leaflet interactions, and TAP characteristics.
摘要：
目的：跨环形补片（TAP）右室流出道（RVOT）修复法洛四联症的肺动脉瓣（PV）单峰重建在不同的手术方法中具有不同的临床结果。研究目的是系统地评估单核小叶设计参数如何影响体外瓣膜功能。
方法：3D打印，在三种婴儿生理条件下测试了疾病特异性RVOT模型。将单孔针缝到模型中，天然主肺动脉（MPA）形成后壁，占z评分为零的PV环和MPA直径的重建周长的40％和50％（天然PVz评分-3.52和-2.99对于BSA0.32m2）。各种小叶自由边缘长度（FEL）（相对于后壁），位置（相对于PVSTJ），和扇贝深度在两个模型中进行了研究。压力梯度,返流,采用描述性统计和回归模型进行分析。
结果：增加FEL超过MPA后壁的100％降低了梯度，但轻度增加了反流，达到25％的峰值。与STJ放置相比，每个FEL的自由边缘超过STJ2mm，梯度略有增加，而反流没有显着变化。扇贝小叶会影响性能。预折叠小叶改善了移动性并略微降低了梯度。
结论：平衡梯度，返流,为了增长而扩大规模，一组传单设计已被选择用于临床前评估。40％后壁模型中的小叶宽度为140-160％的设计（50％后壁中的110-120％），位于或超过STJ2毫米，展示了最好的结果。离体测试的下一阶段将另外考虑天然RVOT扩张性，天然小叶相互作用，和TAP特征。
方法：3D打印，在三种婴儿生理条件下测试了疾病特异性RVOT模型。将单孔针缝到模型中，天然主肺动脉（MPA）形成后壁，占z评分为零的PV环和MPA直径的重建周长的40％和50％（天然PVz评分-3.52和-2.99对于BSA0.32m2）。各种小叶自由边缘长度（FEL）（相对于后壁），位置（相对于PVSTJ），和扇贝深度在两个模型中进行了研究。压力梯度,返流,采用描述性统计和回归模型进行分析。
结果：增加FEL超过MPA后壁的100％降低了梯度，但轻度增加了反流，达到25％的峰值。与STJ放置相比，每个FEL的自由边缘超过STJ2mm，梯度略有增加，而反流没有显着变化。扇贝小叶会影响性能。预折叠小叶改善了移动性并略微降低了梯度。
结论：平衡梯度，返流,为了增长而扩大规模，一组传单设计已被选择用于临床前评估。40％后壁模型中的小叶宽度为140-160％的设计（50％后壁中的110-120％），位于或超过STJ2毫米，展示了最好的结果。离体测试的下一阶段将另外考虑天然RVOT扩张性，天然小叶相互作用，和TAP特征。
