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Investigation of Usefulness of "Recovery-Directed Left Ventricular Assist Device" invented based on a new concept

基于新概念发明的“恢复导向左心室辅助装置”的实用性研究

基本信息

批准号：
13480299
负责人：
MIYAWAKI Fujio
金额：
$ 7.68万
依托单位：
Tokyo Denki University
依托单位国家：
日本
项目类别：
Grant-in-Aid for Scientific Research (B)
财政年份：
2001
资助国家：
日本
起止时间：
2001 至 2003
项目状态：
已结题

来源：
https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-13480299/
关键词：
Recovery-Directed Left Ventricular Assist Device valved apical conduit afterload-controlling chamber continuous-flow type blood pump apical valve size compliance afterload reduction restriction of ventricular relaxation and dilatation 重症左心

项目摘要

Recovery-Directed Left Ventricular Assist Device (RDLVAD) is a new type LVAD characterized by remarkable reduction in ventricular afterload during systole and no restriction of ventricular relaxation or dilatation during diastole, thereby promoting cardiac recovery. It consists of a valved apical conduit, a compliant afterload-controlling chamber (ACC), and a continuous-flow type blood pump. In both experiments using a mock circulation and isolated perfused rabbit hearts, we investigated sizes and properties of the main components that are appropriate for RDLVAD to achieve the above features.1.In the state of severe left heart failure represented in the mock circulation, the effect of each of 12 combinations made between 3 different apical valves and 4 different ACCs on the left ventricular pressure (LVP), the ACC pressure and the maximum cardiac output was studied. The apical valves, 9 and 13 mm in internal diameter, were too small to reduce the ventricular load. The 18-mm apical valve, whose opening area was 60% of that of the 23-mm aortic valve, and the ACC half as large as the stroke volume were smallest for constantly achieving significant reduction in ventricular afterload and sufficient blood supply ; the developed pressure as low as a mean systolic LVP of 27mmHg and a peak LVP of 47mmHg was capable of producing a maximum cardiac output (=maximum pump flow) of 5.8L/min even if the compliance of ACC was as low as 0.1-0.6mL/mmHg.2.We have warned that continuous-flow type LVADs increase the risk of impeding ventricular relaxation and filling as a pump flow rate rises. This phenomenon was shown both in the mock circulation and animal experiments. In some isolated hearts, heart rate also suddenly increased when the pump flow was raised. On the other hand, the RDLVAD did not restrict ventricular relaxation or filling.

恢复导向左心室辅助装置（RDLVAD）是一种新型的LVAD，其特点是收缩期心室后负荷显著降低，舒张期心室舒张或扩张不受限制，从而促进心脏恢复。它由一个带瓣心尖导管、一个顺应性后负荷控制室（ACC）和一个连续流动型血泵组成。在模拟循环和离体灌流兔心的实验中，我们研究了RDLVAD的主要组成部分的尺寸和性能，以实现上述功能：1.在模拟循环中，在严重左心衰的状态下，3种不同的心尖瓣和4种不同的ACC之间的12种组合对左心室压力（LVP）的影响，研究ACC压力和最大心输出量。心尖瓣内径分别为9 mm和13 mm，太小，无法降低心室负荷。18 mm心尖瓣开口面积为23 mm主动脉瓣开口面积的60%，ACC为每搏输出量的1/2，持续显著降低心室后负荷，维持充足的血供;当平均收缩期LVP为27 mmHg，峰值LVP为47 mmHg时，可产生最大心输出量即使ACC的顺应性低至0.1-0.6mL/mmHg，最大泵流量也为5.8L/min。2.我们已经警告过，随着泵流量的增加，连续流型LVAD会增加阻碍心室舒张和充盈的风险。这一现象在模拟循环和动物实验中都得到了证实。在一些离体心脏中，当泵流量增加时，心率也会突然增加。另一方面，RDLVAD不限制心室舒张或充盈。