Agwu Nnaoma, Chau Daryl, Kelley Gregory S, Burney Tanya, Perminov Ekaterina, Alcantara Christopher, Recto Michael R, Kheradvar Arash
Department of Biomedical Engineering University of California Irvine CA USA.
Children's Hospital of Orange County Orange CA USA.
J Am Heart Assoc. 2025 Jul;14(13):e041932. doi: 10.1161/JAHA.125.041932. Epub 2025 Jun 18.
Congenital heart defects affect approximately 1% of births in the United States and Europe, with >1 million children in the United States living with congenital heart defects. Many experience abnormalities in the right ventricular outflow tract, often necessitating surgical intervention early in life. However, the initial repairs typically are temporary solutions as many patients will eventually need pulmonary valve replacement to address pulmonary valve regurgitation and prevent right ventricle failure. Addressing progressive pulmonary valve regurgitation, ideally in patients weighing 8 to 10 kg, is critical to prevent right ventricle dysfunction. Transcatheter pulmonary valve replacement currently treats patients weighing at least 20 kg. Unfortunately, smaller children must wait for valve replacement and risk right ventricular dilation.
To address this challenge, we have developed the IRIS Valve, a growth-accommodating transcatheter pulmonary heart valve inspired by origami targeting implantation in at least 8 kg children. The valve stent underwent finite element analysis with validation by fracture testing. Using a 12-Fr transcatheter system, the IRIS valve was implanted into 8 to 17 kg Yucatan mini pigs for 6 months.
Benchtop fracture testing and finite element analysis confirmed the stent's ability to be crimped to a 3-mm diameter for loading into a 12-Fr transcatheter system and expanded to 20 mm without fracture. Animal studies successfully demonstrated excellent integration within the pulmonary valve annulus, intact valve integrity, and favorable tissue response.
The IRIS Valve offers a promising solution for earlier treatment of heart valve disease in pediatric patients with congenital heart defects, potentially improving outcomes in this vulnerable population.
在美国和欧洲，先天性心脏缺陷影响约1%的新生儿，美国有超过100万儿童患有先天性心脏缺陷。许多患者存在右心室流出道异常，常常需要在生命早期进行手术干预。然而，最初的修复通常只是临时解决方案，因为许多患者最终需要进行肺动脉瓣置换，以解决肺动脉瓣反流并预防右心室衰竭。在体重8至10千克的患者中解决进行性肺动脉瓣反流对于预防右心室功能障碍至关重要。目前，经导管肺动脉瓣置换术用于治疗体重至少20千克的患者。不幸的是，年龄较小的儿童必须等待瓣膜置换，面临右心室扩张的风险。
为应对这一挑战，我们研发了IRIS瓣膜，这是一种受折纸启发的可生长适应的经导管肺动脉心脏瓣膜，目标是植入至少8千克的儿童体内。对瓣膜支架进行了有限元分析，并通过断裂测试进行验证。使用12F经导管系统，将IRIS瓣膜植入8至17千克的尤卡坦小型猪体内6个月。
台架断裂测试和有限元分析证实，该支架能够被压接到3毫米直径以便装入12F经导管系统，并能扩张至20毫米而不发生断裂。动物研究成功证明了其在肺动脉瓣环内的良好整合、完整的瓣膜完整性以及良好的组织反应。
IRIS瓣膜为先天性心脏缺陷的儿科患者早期治疗心脏瓣膜疾病提供了一种有前景的解决方案，可能改善这一脆弱人群的治疗结果。
