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科患者需要心室辅助装置（VAD）。副作用 柏林心脏EXCOR仍然是FDA批准的唯一用于儿科患者的VAD。这种横膈膜移位 泵体积小/重量轻，便于维护。然而，EXCOR以不同的速度抽取和泵送血液， 间歇性搏动性血流的时间，其引流和输注插管仅一半时间起作用 (50%效率）。EXCOR还会产生高峰血液流速，可能导致血液损伤。一 旁路连续流（PediMag/CentriMag）VAD也已与柏林心脏插管一起使用， 小的孩子，但它庞大/沉重的马达阻碍了步行。儿科旁心室辅助装置需要两个 用于抽出和输注的单独的套管及其安装需要侵入性正中胸骨切开术， 这使得以后的心脏移植或修复手术变得复杂。我们的最终目标是发展一个最低限度的 用于儿科患者的有创、高效旁心搏动性膈肌位移VAD系统。 使能技术是一种带有集成顺应性腔的经心尖双腔插管（DLC） 其特点是：1）通过微创小左胸切口进行单次经心尖插管; 2）两个集成 顺应性腔室：a）连续抽取/输注血液，以提高效率，实现更高的血流量 B）调节连续血流波动以获得所需的脉动性; c）降低峰值血流速率以缓解 d）降低输注腔峰值压力，降低泵后负荷以提高泵输出; e）允许从抽液到输注的平稳过渡，以实现高频泵送。对一个初始的 带有EXCOR的集成顺应性腔室原型的经心尖DLC显示出双泵送流量 降低了峰值泵流量。I期SBIR目标：我们将重新设计经心尖DLC， 最小顺应性试验室，并在羔羊中进行性能测试。具体目标1：设计， 制造并台架测试具有集成顺应性腔室的高效经心尖DLC。 经心尖DLC顺应性腔室将集成到引流和输注出口中。24 Fr DLC主体将是一体式增强聚氨酯。超弹性硅胶顺应腔将 非常小，每搏输出量为50%。最终原型将在EXCOR模拟循环中进行为期1周的测试 添加37%甘油，确保性能/可靠性/耐用性。具体目标2：测试新型24 Fr经心尖 在羔羊EXCOR VAD回路中使用具有顺应性腔室的DLC（n=8）。这些羔羊（10-15公斤）的研究 将研究经心尖展开的难易程度、6小时体内性能/可靠性和初始生物相容性。 原型设计/制造/台架试验将在W-Z Biotech完成，动物研究将在 肯塔基州大学。完成后，具有集成顺应性的商业化经心尖DLC 腔室将提供具有双倍效率的侵入性较小的旁心搏动性VAD。这项技术可以 也可用于成人，并可能显著影响心源性休克/心脏移植管理的过渡。

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.