Use of Aortic Valvo-Pumps Placed in Valve Annulus for Long-Term Left Ventricular Assist

Qian, Kunxi; Wang, Dongfang; Topaz, Stephen R.; Ru, W M; Zeng, Peng; Huang, Yuan; Wang, Hao; Wang, Fang-Qung; Feng, Zi-Gang; Zwischenberger, Joseph B.

doi:10.1097/01.mat.0000185914.88497.9e

Cited by 9 publications

(8 citation statements)

References 12 publications

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“…These have been attributed to continuous aortic valve closure during cf-LVAD support. Moreover, the lack of pulsatility and the absence of aortic valve movement with cf-LVAD support have also been linked to the increased incidence of gastrointestinal bleeding in these patients (4,5). Therefore, some centers have strived to achieve intermittent aortic valve opening in their LVAD patients (6).…”

Section: Pump Speed Waveform Analysis To Detect Aortic Valve Opening mentioning

confidence: 99%

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Initial Acute Animal Experiment Using a New Miniature Axial Flow Pump in Series With the Natural Heart

et al. 2015

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We have advocated an axial flow blood pump called "valvo pump" that is implanted at the aortic valve position, and we have developed axial flow blood pumps to realize the concept of the valvo pump. The latest model of the axial flow blood pump mainly consists of a stator, a directly driven impeller, and a hydrodynamic bearing. The axial flow blood pump has a diameter of 33 mm and length of 74 mm, and the length of anatomical occupation is 33 mm. The axial flow blood pump is anastomosed to the aorta with polytetrafluoroethylene (PTFE) cuffs worn on the inflow and outflow ports. Dp-Q curves of the axial flow blood pump are flatter than those of ordinary axial flow pumps, and pump outflow of 5 L/min was obtained against a pressure difference of 50 mm Hg at a rotational speed of 9000 rpm in vitro. The axial flow blood pump was installed in a goat by anastomosing with the thoracic descending aorta using PTFE cuffs, and it was rotated at a rotational speed of 8000 rpm. Unlike in case of the ventricular assistance in parallel with the natural heart, pulsatilities of aortic pressure and aortic flow were preserved even when the pump was on, and mean aortic flow was increased by 1.5 L/min with increase in mean aortic pressure of 30 mm Hg. In conclusion, circulatory assistance in series with the natural heart using the axial flow blood pump was able to improve hemodynamic pulsatility, and it would contribute to improvement of end-organ circulation. .

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Section: Pump Speed Waveform Analysis To Detect Aortic Valve Opening mentioning

confidence: 99%

“…Qian et al. have also developed a third‐generation axial flow pump that can be implanted at the aortic valve position . Our latest axial flow blood pump, the third‐generation blood pump, consists of a direct‐drive impeller, a hybrid bearing including a passive magnetic bearing and a hydrodynamic bearing .…”

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confidence: 99%

Initial Acute Animal Experiment Using a New Miniature Axial Flow Pump in Series With the Natural Heart

et al. 2015

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“…Therefore, these three pumps may meet the hemodynamic requirements of patients with body weights of 40–60 kg, 60–80 kg, and 80–100 kg, respectively. The devices occupy no additional anatomical space and deliver the blood directly from the ventricle to the aorta, thus producing less physiological disturbance to the natural circulation (25,26). In 2005, the first in vivo trial of this device demonstrated that the 25‐mm aortic valvo‐pump can be sewn onto the aortic valve annulus of an 80‐kg pig without injury to adjacent tissues and organs (27).…”

Section: Rotary Pumpsmentioning

confidence: 99%

Development of Mechanical Circulatory Support Devices in China

Wang¹,

Zhang²,

Ding³

2009

Artificial Organs

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Myocardial dysfunction leading to low cardiac output syndrome is a common clinical pathophysiological state. Currently, the use of mechanical circulatory support (MCS) is an essential aspect of the treatment of patients with cardiac failure. Several groups in China are engaged in the design and development of MCS devices. These devices can be classified as pulsatile, rotary, and total artificial heart (TAH). There are two types of pulsatile pump, which are driven by air (pneumatic). One of these pumps, the Luo-Ye pump, has been used clinically for short-term support since 1998. The other is a push-plate left ventricular device, which has a variable rate mode. Various rotary devices are classified into axial and centrifugal pumps, depending on the impeller geometry. Most rotary pumps are based on the maglev principle, and some types have been used clinically. Others are still being studied in the laboratory or in animal experiments. Furthermore, certain types of total implantable pump, such as the UJS-III axial pump and the UJS-IV aortic valvo-pump, have been developed. Only one type of TAH has been developed in China. The main constituents of this artificial heart are two axial pumps, two reservoir tanks mimicking the right and left atria, flow meters, two pressure gauges, and a resistance adaptor. Although the development of mechanical assist devices in China is still in a nascent stage, a number of different types of MCS devices are currently being studied.

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“…For long-term left ventricular assist, aortic valvo-pumps were developed [1][2][3][4]8], which deliver the blood directly from ventricle to aorta without connecting tubes and bypass circle, thus have less dangers of thrombus formation outside the pump. In the inside of the pump, regurgitation can wash out the blood contacting surfaces in the gap between the rotor and the stator and can prevent the formation of micro-thrombus thereafter.…”

Section: Introductionmentioning

confidence: 99%

Study on regurgitation of a bearing-less mini axial aortic valvo-pump with closed impeller

Qian¹

2009

Health

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The back-flow of an aortic valvo-pump will re-duce the pumping flow rate but can wash out the gap between the rotor and the stator, and thus can improve the antithrombogenicity of the de-vice. To investigate the regurgitation of a 23mm OD aortic valvo-pump, its closed impeller was replaced by a cylinder and hereby the valvo- pump had lost its pumping function. The pres-sure head crossing the aortic valvo-pump was maintained by a locally made pulsatile centrifugal pump, beating rhythmically from 30 to 120mmHg. The back flow from outlet to inlet of valvo-pump via the above-mentioned gap was measured. Results demonstrated that this gap and the pressure head had remarkable effect on back- flow; a larger gap and/or a larger pressure head would lead to a larger back-flow. By 0,20mm gap and 100mmHg pressure head, the valvo-pump had ca. 0,8 l/min back-flow. Instantaneous meas-urement indicated that the back-flow had a pul-satile form with high rate during diastole while low rate during systole of the natural heart imi-tated by pulsatile centrifugal pump. The pump rotated at 12500rpm, 15000rpm and 17500rpm respectively, but it was found the rotating speed had no affection on back-flow. This investigation provides a basis for pump design seeking for both increase of the flow rate and improvement of the compatibility; the former is particularly important for a mini axial pump and the latter is extremely difficult for closed impeller

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Use of Aortic Valvo-Pumps Placed in Valve Annulus for Long-Term Left Ventricular Assist

Cited by 9 publications

References 12 publications

Initial Acute Animal Experiment Using a New Miniature Axial Flow Pump in Series With the Natural Heart

Initial Acute Animal Experiment Using a New Miniature Axial Flow Pump in Series With the Natural Heart

Development of Mechanical Circulatory Support Devices in China

Study on regurgitation of a bearing-less mini axial aortic valvo-pump with closed impeller

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