Development of a Small Implantable Right Ventricular Assist Device (original) (raw)
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Initial In Vivo Evaluation of the DexAide Right Ventricular Assist Device
ASAIO Journal, 2005
Objectives: Despite the increasing use of left ventricular assist devices for patients with end-stage congestive heart failure, no implantable, centrifugal right ventricular assist devices (RVADs) are available for those patients with significant right ventricular failure. The DexAide RVAD was developed to provide an implantable RVAD option to surgeons. The aim of this study was to evaluate pump performance in an acute in vivo model.
IN VIVO EVALUATION OF THE CorAide RIGHT VENTRICULAR ASSIST DEVICE (RVAD)
ASAIO Journal, 2005
The conventional pneumatic drivers for ventricular assist device(VAD) have been relatively large in size and heavy in weight. Recently, portable size drivers are developed and applied in clinical area to give the patients extended scope of activity and convenience of daily life. Additionally, they contributed out of hospital home discharge of pneumatic VAD patients in the clinical aspect. There is still possibility of reducing the size and weight of the pneumatic driver for wearable size. In this paper, simple driving mechanism is suggested for electropneumatic biventricular assist device actuator with smaller size and reduced weight. Our electropneumatic actuator is composed of brushless DC motor, ball screw, two push plates and bellows as major part. The push plates modulate the volume of the bellows. This bellows volume change generates the pressure of the pneumatic circuit for blood pumping. The bellows is manufactured by dipping process with durable polyurethane. The bellows mechanism enabled smaller driver size of 20x30x8cm 3 and reduced weight of 4.0kg including the actuator, controller and battery. To restore the gas leakage, gas compensating system is included, and the short range wireless monitoring is possible with bluetooth module. This wireless monitor/controlling function will improve the mobility of the patients. From the in vitro experiment result, this driver can support 6.5L/min at 100 bpm. And the in vivo animal study showed good performance as biventricular assist device.
Development of DexAide Right Ventricular Assist Device: Update II
Asaio Journal, 2008
The DexAide right ventricular assist device (RVAD) is a magnetically and hydrodynamically levitated implantable centrifugal pump. Recent progress includes (1) redesign of the inflow/outflow conduits, which yielded two successful 3-month experiments, (2) development of alternative journal bearing materials, and (3) completion of an 18-month duration of in vitro endurance testing. Verification testing of the RVAD electronics has been completed, and a prototype biventricular assist device (BVAD) system has been tested. Acute DexAide/CorAide BVAD implantations via median sternotomy in two calves documented BVAD control algorithms and anatomical fit. A drug-induced calf chronic heart failure model, currently under development in our laboratory, resulted in a successful BVAD implantation in a calf with heart failure. Our future plans are to complete in vitro and in vivo validation of alternative bearing materials, perform preclinical DexAide in vivo and in vitro reliability studies, and obtain FDA approval for an Investigational Device Exemption to conduct a clinical pilot study. Two successful 3-month in vivo experiments and an 18-month in vitro endurance test were completed. Following final bearing material selection, the DexAide design will be "frozen" so that preclinical systems can be manufactured. BVAD experiments using a chronic heart failure model are in progress.
The Annals of Thoracic Surgery, 2012
Although the need for right ventricular assist device (RVAD) support for right ventricular failure after the implantation of a continuous-flow left ventricular assist device has decreased, right ventricular failure still occurs in as many as 44% of patients after continuous-flow left ventricular assist device insertion. Cleveland Clinic's DexAide continuous-flow RVAD was implanted in 34 calves during the course of its development. This review discusses lessons learned in the design and development of an implantable continuous-flow RVAD that are drawn from the results of these in vivo studies, our clinical experience with RVAD support, and a review of previously published reports on clinical RVAD use.
Human Clinical Fitting Study of the DexAide Right Ventricular Assist Device
Artificial Organs, 2009
The DexAide right ventricular assist device (RVAD) has been developed as an implantable RVAD.The purpose of this study was to determine the final design and optimal anatomical placement of the DexAide RVAD when implanted simultaneously with either of two commercially available left ventricular assist devices (LVADs) in patients. A mock-up DexAide RVAD was used to assess configuration with each of two types of commercially available LVADs at the time of LVAD implantation in three human clinical cases. The pump body of the DexAide RVAD was placed either in the preperitoneal space or in the right thoracic cavity. The DexAide RVAD placed into the right thoracic cavity is suitable for use with the Novacor or HeartMate II LVADs. The results of this study will guide the finalization of the inflow cannula and optimal placement of the DexAide RVAD for human clinical trials.
Development of the DexAide Right Ventricular Assist Device Inflow Cannula
Asaio Journal, 2008
The DexAide right ventricular assist device (RVAD) is a magnetically and hydrodynamically levitated implantable centrifugal pump. Recent progress includes (1) redesign of the inflow/outflow conduits, which yielded two successful 3-month experiments, (2) development of alternative journal bearing materials, and (3) completion of an 18-month duration of in vitro endurance testing. Verification testing of the RVAD electronics has been completed, and a prototype biventricular assist device (BVAD) system has been tested. Acute DexAide/CorAide BVAD implantations via median sternotomy in two calves documented BVAD control algorithms and anatomical fit. A drug-induced calf chronic heart failure model, currently under development in our laboratory, resulted in a successful BVAD implantation in a calf with heart failure. Our future plans are to complete in vitro and in vivo validation of alternative bearing materials, perform preclinical DexAide in vivo and in vitro reliability studies, and obtain FDA approval for an Investigational Device Exemption to conduct a clinical pilot study. Two successful 3-month in vivo experiments and an 18-month in vitro endurance test were completed. Following final bearing material selection, the DexAide design will be "frozen" so that preclinical systems can be manufactured. BVAD experiments using a chronic heart failure model are in progress.
Current Trends in Implantable Left Ventricular Assist Devices
Cardiology Research and Practice, 2011
The shortage of appropriate donor organs and the expanding pool of patients waiting for heart transplantation have led to growing interest in alternative strategies, particularly in mechanical circulatory support. Improved results and the increased applicability and durability with left ventricular assist devices (LVADs) have enhanced this treatment option available for end-stage heart failure patients. Moreover, outcome with newer pumps have evolved to destination therapy for such patients. Currently, results using nonpulsatile continuous flow pumps document the evolution in outcomes following destination therapy achieved subsequent to the landmark Randomized Evaluation of Mechanical Assistance for the Treatment of Congestive Heart Failure Trial (REMATCH), as well as the outcome of pulsatile designed second-generation LVADs. This review describes the currently available types of LVADs, their clinical use and outcomes, and focuses on the patient selection process.
JTCVS Open, 2020
Background: The Advanced ventricular assist device (Advanced VAD) is designed as a universal pump intended to prevent backflow in the event of pump stoppage, to maintain physiological pulse pressure, and to be used as both a left and right VAD. The purpose of this study was to evaluate the performance of the Advanced VAD as both a left and right VAD in an acute in vivo study in calves. Methods: The Advanced VAD was implanted through a median sternotomy in 5 healthy calves (weight, 71.4-91.2 kg) as a left VAD (n ¼ 3) or a right VAD (n ¼ 2). After implantation, hemodynamic parameters, including general performance and pump stoppage, were evaluated. Results: The Advanced VAD was successfully implanted as a left and right VAD without cardiopulmonary bypass. The speed range of the Advanced VAD was 2500 to 3500 rpm as a left VAD and 2000 to 2500 rpm as a right VAD. Up to 4.3 L/min was achieved for both left and right VAD configurations. To demonstrate the automatic shut-off feature, the pump was stopped without clamping the outflow graft. The outflow graft was then clamped, which produced no significant changes in the arterial pressure waveform. The pulse pressures under the left VAD
European journal of cardio-thoracic surgery : official journal of the European Association for Cardio-thoracic Surgery, 2014
The implantable continuous-flow left ventricular assist devices (LVADs) HeartMate II (HM II) and HeartWare HVAD (HW) underwent design modifications. The impact of these changes on life-threatening pump malfunctions was evaluated. We retrospectively analysed pump malfunctions due to thrombosis or cable damage in patients supported with primarily implanted HM II (n = 191) and HW (n = 347), separated into patients supported with the old and new pump designs. In 2010, the cable strain relief of the HM II device was improved (132 patients with old and 79 with new) and sealed grafts were introduced (68 patients with sealed inflow connector and outflow graft and 125 without). In 2011, titanium sintering of the inflow cannula of HW pumps was introduced (137 patients with a non-sintered and 210 with a sintered inflow cannula). The median support time was 1.12 (0-6.1) years for all HM II and 0.59 (0-4.2) years for all HW patients. The cumulative rate of events per patient-year (EPPY) was 0.11...