Pediatric Transapical Double Lumen Cannula with Integrated Compliance Chambers Doubles Flow of Paracorporeal Pulsatile VAD

患有严重心力衰竭的儿童患者需要使用心脏辅助装置(VAD)。《幻影》 柏林心脏EXCOR仍然是FDA批准的唯一用于儿科患者的VAD。该隔膜位移 泵体积小/重量轻，便于移动。然而，EXCOR在不同的时间抽出和泵血 搏动性血流中断的时间，其引流和输液插管只有一半的时间起作用 (50%效率)。Excor还会产生较高的峰值血流率，这可能会导致血液损伤。一个 旁心脏持续流动(PediMag/CentriMag)VAD也已与柏林心脏插管一起用于 儿童较小，但其笨重的马达阻碍了行走。儿科准心脏VAD需要两个 分离的拔管和输液插管及其安装需要侵入性的胸骨正中切开术， 这使后来的心脏移植或修复手术变得复杂。我们的最终目标是开发一种最低限度的 用于儿科患者的侵入性、高效的准心脏搏动性横隔膜置换VAD系统。 使能技术是带有集成顺应室的经根尖双腔导管(DLC) 其特点是：1)单根经心尖部插管，小创左胸切开；2)两个完整的 顺应室：a)持续抽血/输血以提高效率以获得更高的血流量 心率；b)调整连续的血流波动，以获得所需的搏动性；c)降低峰值血流速度，以缓解 D)降低输液管腔峰值压力，降低泵后负荷，提高泵输出量； E)允许平稳地退出到输液过渡，以实现高频泵送。初步的台架测试 采用EXCOR的集成顺应室原型的经根尖DLC显示双泵流 随着峰值泵流量的降低。第一阶段SBIR的目标：我们将重新设计一个最佳的经根尖DLC 最低限度的合规性试验室，并在羔羊身上进行性能测试。具体目标1：设计、 制造和台架测试具有集成顺应室的高效率、跨根尖的DLC。 经根尖DLC顺应室将集成到引流和输液出口中。24Fr DLC主体将采用一体式增强聚亚安酯。超弹性硅胶顺应室将 要非常小，要有50%的冲程。最终的原型将在EXCOR模拟循环中进行为期一周的测试 含37%甘油的性能/可靠性/耐用性。具体目标2：测试新的24Fr经根尖 8只羔羊EXCOR VAD电路中有顺应室的DLC(n=8)。这些羊肉(10-15公斤)研究 将研究经根尖部署的易用性、6小时体内性能/可靠性和初始生物相容性。 原型设计/制造/台架测试将在W-Z Biotech进行，动物研究将在 肯塔基大学。完成后，商业化的跨根尖DLC与集成的顺应性 Chambers将提供一种侵入性较小的准心脏搏动性VAD，其效率将提高一倍。这项技术可以 也可用于成人，并可能显著影响心源性休克/过渡到心脏移植治疗。

Pediatric patients with severe heart failure require a ventricular assist device (VAD). The paracorporeal Berlin Heart EXCOR is still the only FDA-approved VAD for pediatric patients. This diaphragm displacement pump is small/light weight to facilitate ambulation. However, EXCOR withdraws and pumps blood at different times for interrupted pulsatile blood flow, with its drainage and infusion cannulas functioning only half the time (50% efficiency). EXCOR also generates a high peak blood flow rate, which may cause blood damage. A paracorporeal continuous flow (PediMag/CentriMag) VAD has also been used with Berlin Heart cannulas in smaller children, but its bulky/heavy motor hinders ambulation. Pediatric paracorporeal VADs require two separate cannulas for withdrawal and infusion and their installation requires an invasive median sternotomy, which complicates later surgery for heart transplant or repair. Our ultimate goal is to develop a minimally invasive, high efficiency paracorporeal pulsatile diaphragm displacement VAD system for pediatric patents. The enabling technology is a transapical double lumen cannula (DLC) with integrated compliance chambers that features: 1) Single transapical cannulation via less invasive, small left thoracotomy; 2) Two integrated compliance chambers that: a) Continuously withdraw/infuse blood to increase efficiency for higher blood flow rates; b) Adjust continuous flow fluctuation for desired pulsatility; c) Reduce peak blood flow rate to mitigate blood trauma; d) Reduce infusion lumen peak pressure, decreasing pump afterload to enhance pump output; e) Allow smooth withdrawal to infusion transition for high frequency pumping. Bench testing of an initial transapical DLC with integrated compliance chambers prototype with EXCOR showed double pumping flow with decreased peak pump flow. The Phase I SBIR objective: We will redesign a transapical DLC with optimal minimal compliance chambers and conduct performance testing in lambs. Specific Aim 1: To design, fabricate, and bench test the high efficiency, transapical DLC with integrated compliance chambers. The transapical DLC compliance chambers will be integrated into the drainage and infusion outlets. The 24 Fr main DLC body will be one-piece reinforced polyurethane. The super-elastic silicone compliance chambers will be very small with 50% stroke volume. The final prototype will be tested for 1 week in an EXCOR mock loop with 37% glycerin for performance/reliability/durability. Specific Aim 2: To test the new 24 Fr transapical DLC with compliance chambers in an EXCOR VAD circuit in lambs (n=8). These lamb (10-15 kg) studies will investigate ease of transapical deployment, 6 hr in vivo performance/reliability, and initial biocompatibility. Prototype design/fabrication/bench testing will be done at W-Z Biotech, and the animal studies will be done at the University of Kentucky. Upon completion, the commercialized transapical DLC with integrated compliance chambers will provide a less invasive paracorporeal pulsatile VAD with doubled efficiency. This technology can also be used in adults and may significantly impact cardiogenic shock/bridge to heart transplant management.