Kaplan Aaron V, Devellian Carol, Kim Jamie H, Rotschafer Jessica, Levine Andy, Sommer Robert J, Gray William A
Heart & Vascular Center, Dartmouth Hitchcock Medical Center, Lebanon, New Hampshire.
Conformal Medical, Inc, Nashua, New Hampshire.
J Soc Cardiovasc Angiogr Interv. 2022 Dec 1;2(2):100555. doi: 10.1016/j.jscai.2022.100555. eCollection 2023 Mar-Apr.
The Conformal Left Atrial Appendage System (CLAAS) is a transcatheter implant designed to occlude the left atrial appendage to prevent stroke in patients with nonvalvular atrial fibrillation. The implant incorporates a novel polyurethane polycarbonate-urea foam matrix to enhance device performance. The objective of this study was to characterize the thrombogenicity, sealing, implant integrity, local tissue response, and systemic toxicity of the implant in a healthy canine model.
Devices were evaluated in a chronic canine model using echocardiographic and fluoroscopic guidance (n = 8). Postprocedural echocardiographic evaluation was performed at case completion and at 2, 45, 90, and 150 days. Animals were sacrificed at 90 (n = 4) and 150 (n = 4) days. Necropsy included gross, x-ray, and histologic examination.
CLAAS implants were implanted in all animals successfully on the basis of fluoroscopic, intracardiac echo, and transthoracic echo criteria. Although 2 animals were noted to have leaks (1 at implantation and 1 at day 90 post procedure before sacrifice), both were of <5 mm. All left atrial appendages were completely sealed on gross examination. No device-related thrombus, pericardial effusion, or evidence of distal organ emboli was observed. All implants maintained their structural integrity and were well integrated within the tissue. There was no histologic evidence of toxicity noted in the downstream organs or tissues.
The CLAAS implant can be deployed providing a good seal for up to 150 days without signs of local or systemic toxicity in a canine model.
适形左心耳系统（CLAAS）是一种经导管植入装置，旨在封堵左心耳，以预防非瓣膜性心房颤动患者发生中风。该植入装置采用了一种新型聚氨酯聚碳酸酯 - 脲泡沫基质，以提高装置性能。本研究的目的是在健康犬模型中表征该植入装置的血栓形成性、密封性、植入完整性、局部组织反应和全身毒性。
在慢性犬模型中使用超声心动图和荧光透视引导对装置进行评估（n = 8）。在病例完成时以及术后2、45、90和150天进行术后超声心动图评估。在90天（n = 4）和150天（n = 4）时对动物实施安乐死。尸检包括大体检查、X线检查和组织学检查。
根据荧光透视、心内超声和经胸超声标准，所有动物均成功植入CLAAS植入装置。尽管注意到2只动物存在渗漏（1只在植入时，1只在术后90天处死前），但两者渗漏均<5 mm。所有左心耳在大体检查时均完全密封。未观察到与装置相关的血栓、心包积液或远端器官栓塞的证据。所有植入装置均保持其结构完整性，并在组织内良好整合。在下游器官或组织中未发现组织学毒性证据。
在犬模型中，CLAAS植入装置可成功植入，提供良好的密封长达150天，且无局部或全身毒性迹象。
