An anatomically compatible, wearless, reliable, and nonthrombogenic centrifugal blood pump

Effective anticoagulation regimens are needed to reduce risks of thrombosis and bleeding in animal models of ventricular assist device to verify its hemocompatibility, biologic safety and reliability. This study is to develop a validated anticoagulation procedure for a sheep model to test the newly developed CH-VAD. CH-VAD models were established in six healthy sheep by constructing blood bypass of left ventricle → ventricular assist device → descending aorta. Heparin infusion was used during operation and in the prior 4 days to maintain activated clotting time 1.5-2.0 times the baseline. From the third day, proper dosage of warfarin was used orally to maintain international normalized ratio values within the range of 1.2-2.0. After termination, we examined whether there was thrombosis in the blood pump, grafts, and anastomotic stoma. Macroscopic and histopathologic examinations were performed in major organs to check for congestion and infarction. Bleeding complications were not found in any animals throughout the experiments. Activated clotting time values were 326 ± 33 s intraoperatively and 157 ± 28 s in the prior 4 days postoperatively. Activated partial thromboplastin time values increased slowly and reached the lower limit of the target range on the fourth day. Only in one of six cases was thrombus or fibrosis tissue found in the blood flow channel of the pump. Pathologic analysis showed no thrombosis, necrosis and microembolus in end-stage organs. Under the anticoagulation regimens, coagulation system could be well controlled to avoid thrombosis and bleeding complications in sheep models for CH-VAD.

Section: Discussionmentioning

confidence: 99%

Preclinical Study of Anticoagulation Regimens in Sheep After Implantation of CH‐VAD Blood Pump

Liu

et al. 2016

“…Earlier studies with this device were also performed in sheep model without anticoagulation. A combined duration of 341 implant dates was achieved without signs of thrombosis at the time of autopsy (67).…”

Section: Effect Of Device Typementioning

confidence: 99%

In Vivo Preclinical Anticoagulation Regimens After Implantation of Ventricular Assist Devices

Saeed¹,

Fukamachi²

2009

Ventricular assist devices (VADs) have demonstrated successfully their ability to treat failing circulation of patients with end-stage heart failure. Among the main obstacles with these VADs is thromboembolic events that increase device-related morbidity and mortality. Prior to the clinical application of any newly developed VAD, the feasibility of the device is tested on animal models. Animal species have different hemostatic properties than human patients, and this factor creates a margin of error when comparing the occurrence of VAD-induced thrombosis in an animal versus a human. This detailed literature review provides a thorough documentation of various preclinical anticoagulation protocols used to date, including their outcomes and recommendations for future anticoagulation management strategies. In summary, the outcomes favor a sheep or pig model over other animal models, and discourage the application of a single anticoagulative agent to improve outcomes with any of the currently available devices.

“…Several are under development. The Heart Mate III is a centrifugal pump powered by magnetic levitation without bearings, as is the Medquest magnetically suspended rotor (MedQuest, Salt Lake City, UT, U.S.A.), or the CorAide developed at the Cleveland Clinic, or the Kriton Medical blood pump (Kriton Medical, Sacramento, CA, U.S.A.), advocated as being less thrombogenic (21). Long-term animal studies have been successful with similar design and the Terumo pump (22).…”

Section: Is This Technology Safe and Reliable?mentioning

confidence: 99%

Rotary Blood Pumps for Cardiac Assistance: A “Must”?

Mesana

2004

Ventricular Assist Devices (VADs) were developed following the observation that most end-stage heart failure patients only required left heart support for survival. The trend toward left VAD implantation instead of a TAH has actually contributed to the development of nonpulsatile rotational devices. This article intends to evaluate the current and future technology of continuous flow pumps. Various issues pertaining to the long-term effects of continuous blood flow, biocompatibility of axial flow pumps, and the safety and reliability of such devices need to be addressed. Some of the advantages of rotary blood pumps include their small size, ease of implantation, and encouraging low infection rates. Certain issues such as automatic flow control, device components durability, and hemocompatibility remain unresolved. The quest for an ideal device combining optimal efficiency, ease of anatomical fit, and perfect bioacceptance, continues. Rotary blood pumps are not yet a "must."