Ⅰ型血泵左心辅助循环动物实验研究

为了对Ⅰ型血泵进行深入研究以便在此基础上进行改进，我们选择９只心脏正常犬进行左心辅助动物实验，以验证该泵的血液动力学输出性能、对心脏的辅助功能及对血液的破坏程度。在动物实验中，血泵放入胸腔内，进口通过静脉插管经左心房耳插入左心房，出口经过动脉插管插入升主动脉。输液、测试、辅助管路接通后，控制血泵的辅助流量为心输出量的２５～３０％左右。结果显示：１．辅助流量在５００～６００ｍｌ／ｍｉｎ时，主动脉收缩压可达１３０ｍｍＨｇ，证明Ⅰ型血泵输出性能满足辅助时生理血液动力学要求。２．辅助后，主动脉舒张压和心脏总输出量均升高，提示此血泵对冠状动脉血流量的增加及心脏泵血具有辅助功能。３．辅助４小时后，血浆中游离血红蛋白含量由２．４ｍｇ／ｄｌ升高到３．１ｍｇ／ｄｌ，纤维蛋白未发生明显变化，说明此血泵对血液有较轻的破坏     

CH-VAD左心辅助装置动物体内实验研究

验证磁悬浮左心辅助装置(CH-VAD)动物体内植入后的安全性及可靠性。选择健康雄性绵羊6只,经麻醉诱导、呼吸插管后开胸,在心脏不停跳的情况下开通由左心尖到辅助装置,再到降主动脉的辅助循环通路。术后常规予以密切监护及抗凝治疗,持续监测装置运行状况,实验动物在术前及术后分别进行细胞学及血液生化指标检测。实验观察结束后,动物予以安乐死,进行尸检及组织病理检查。6例实验动物中:2例因室颤或窒息死亡,1例因肺部感染于20 d终止观察,2例观察至实验结束(60 d)后取材进行病理检查,1例60 d后继续观察并因肺部感染于135 d终止实验。对成功植入的实验动物进行有效观察,装置悬浮状态良好,运转正常;CH-VAD植入后,细胞学及血液生化检查均在正常范围内。尸解及组织病理检查发现:2例存活 20和135 d的动物,出现肺炎和肾脏多发性梗死;2例存活 60 d的动物,出现肾脏单发小梗死,其余脏器未见明显异常。该实验为CH-VAD临床前评价及临床操作提供理论及技术支持,并证明其具有相对稳定的工作性能;提出建立左心辅助装置临床前评价标准的思路和想法,为后期装置的植入及临床操作提供研究的方向。     

ChinaHeart左心辅助装置的动物在体存活实验

验证磁悬浮离心式左心辅助装置—ChinaHeart VAD的在体血液相容性和可靠性,评估其对实验动物主要终末器官的影响。通过6例健康绵羊的在体存活实验进行评估。在心脏不停跳的情况下,装置入口插入左心尖,出口与降主动脉吻合。术前和术后做血常规、生化及血凝检查,术后连续监测动物存活及辅助装置运行状况。择期动物安乐死后,进行终末主要脏器的宏观和病理学检查。4只羊术后3～28 h内因麻醉或手术意外死亡;2只羊成功复苏并分别辅助20 d和38 d后施行安乐死。对于成功存活的2例实验动物,术后护理期间血常规、生化和血凝检查结果均在正常范围内,辅助装置无机械故障发生。尸检时1只羊(存活20 d)血泵泵体内发现一肉眼可见小块血栓沉积,其余无血栓形成;组织病理检查发现2只羊左肺贴近辅助装置部位均可见有小叶性肺炎,其余终末脏器无明显病变发生。ChinaHeart VAD在体辅助期间血液相容性能良好,对各主要终末脏器无显著影响,具有较好的可靠性;动物存活实验中麻醉呼吸管理和手术操作也至关重要。     

植入式左心辅助装置

到九十年代以后，非植入式左心辅助装置已逐渐发展成为植入式，且气能驱动已由电能驱动所代替。本文简介了左心辅助装置的发展状况，主要介绍了植入式左心辅助装置的结构及特点、材料及其处理、植入方式和目前存在的问题。     

小儿左心辅助心电触发方式下辅助延迟时间的探讨

心电是触发左心辅助同步控制的一个重要的信号源 ,而辅助延迟时间是辅助循环中的一个重要环节。适当的延迟既可以使左心辅助装置 (L VAD)有充分的收缩时间 ,又可以避免 L VAD与心脏在收缩期的冲突 ;如果延迟时间不适当、尤其是在左心房引流不充分时 ,L VAD与心脏的冲突在短时间内就可造成急性左心衰、肺水肿。本文旨在寻找一个经验公式以有效地指导 L VAD延迟时间。目的 :以 R- Ao代表心电 QRS波峰点与主动脉瓣关闭结束的间隔时间 ,以 RR代表 RR间期 ,找出 RR与 R- Ao的相关方程 :R- Ao=A× (RR) n+B。通过加权平均法计算RR的平均值 ,再求出 R- Ao预期值 ,对 R- Ao做安全较正后 ,以此做为辅助的延迟时间。方法 :选择 5～ 14岁行升主动脉导管的小儿患者 ,经筛选 ,测量 45 7例心导管记录图中心电部分的 RR间期以及与此心电对应的主动脉压力波形 ,测量主动脉下降波切迹与 QRS波起始点间的间隔 ,以 R- Ao为因变量 ,以 (RR) n为自变量 ,绘散点图 ,找出相关模型 ,并求出相关方程。结论 :当心率小于 12 0次 / min时 ,相关系数为 0 .733,回归系数为 - 0 .182 ,P值为 2 .2 94E-78;截距为 1.0 70 ,P值为 4.83E- 10 9,相关方程为 :R- Ao=(- 0 .182 ) RR1 /3 +1.0 70。     

气动隔膜型左心辅助泵的研制

较详细地介绍了气动隔膜型左心辅助泵（罗叶泵）Ⅱ型的制作方法及体外和体内测试结果。结果显示Ⅱ型罗叶泵性能可靠，耐疲劳及血液相容性良好，符合临床应用要求。     

轴流泵在左心辅助装置中的应用

轴流泵在左心辅助装置中的应用北京心肺血管医疗研究中心─安贞医院蔺嫦燕左心辅助循环是通过一种辅助泵的装置，将左心的血液引流到泵内再注入主动脉系统，从而减轻左心室负担。采用这种血泵进行辅助循环时，通过左心室顺应性的改变和射血阻抗的降低，能明显改善左心室的...     

植入式左心辅助装置

到九十年代以后，非植入式左心辅助装置已逐渐发展成为植入式，且气能驱动已由电能驱动所代替。本文简介了左心辅助装置的发展状况，主要介绍了植入式左心辅助装置的结构及特点、材料及其处理、植入方式和目前存在的问题。     

20mL小儿罗叶泵的动物存活实验

目的 采用自行研制的20 mL小儿罗叶泵行动物存活实验,明确其对血细胞和重要器官的影响,探讨临床应用的可行性.方法 健康山羊6只,体重（18±3.3）kg.经左侧第5肋间进胸,以左室心尖及降主动脉的插管方式建立左心辅助循环.止血关胸,清醒后拔除气管插管,动物置于专用饲养笼内.辅助期间持续静脉给予肝素抗凝,维持激活全血凝固时间（activated clotting time,ACT）在180～250 s.经颈动、静脉置管监测中心静脉压和血压.在辅助前,辅助后1 h、3h、6 h、10 h、16 h、24 h及存活期间每24 h监测血浆游离血红蛋白,在辅助前及存活期间每24 h检测血常规、肝肾功能、凝血指标.实验结束时取动物心、肝、肾、肺观察病理变化.结果 开胸后插管时发生顽固性室颤死亡1只,其余5只成功进行存活实验,平均存活时间（79.8±60）h.其中因栓塞死亡1只,胸腔出血、肺部感染死亡1只,肝素连接管脱落出血致失血性休克1只,反复气胸、ACT过高致脏器出血1只.1只山羊在存活至预定的7 d时,再次麻醉插管,开胸撤离辅助装置,关胸后顺利拔除气管插管,动物存活.辅助过程中肝素抗凝剂量25～35u/（kg＊h）,所维持的ACT具足够的抗凝效果.中心静脉压、平均动脉压、肝肾功能在辅助前后无明显变化.血浆游离血红蛋白由辅助前的（2.227±1.321）mg/dL升高到辅助72h的（8.873±2.510）mg/dL,二者相比有统计学差异,但在正常生理值范围内.除第1例因抗凝不足产生肾栓塞外,其余4例心、肝、肾、肺的病理检查均无栓塞.结论 20mL小儿罗叶泵血液相容性好,对肝肾功能无不良影响,具备用于临床的条件.     

新型左心辅助装置动力性主动脉瓣的探索性研究

提出左心机械辅助的一种新设想－动力性主动脉瓣,在主动脉瓣的位置设置一可主动旋转的螺旋桨式机械性瓣叶。瓣叶由置于升主动脉腔内的支架笼中心的一对轴承支承。     

基于集中参数模型的左心室辅助装置血流动力学仿真

目的新一代植入式心室辅助装置(ventricular assist device,VAD)采用旋转式血泵(rotary blood pumps)技术,目前已成为治疗严重心力衰竭的重要手段,因而研究VAD与人体间的生理相互作用机制有着重要的意义。本研究通过在Matlab Simulink环境中建立人体心血管循环系统的集中参数数学模型,模拟左心衰患者在植入左心室辅助装置(left ventricular assist device,LVAD)后,循环系统的血流动力学特性。方法通过弹性腔和电路原理建立集中参数模型,主要包括心脏、肺循环、体循环、冠状动脉循环。调整模型的输入值使得模型的仿真结果符合设定的目标值。结果仿真结果证实LVAD可以使心衰患者的总心排量恢复正常,同时对于心脏有明显的除负荷效果、增加冠脉血流量并降低肺动脉楔压,因此可以缓解心衰末期患者重要器官供血不足、心肌缺氧以及肺水肿等并发症。同时通过改变左心室辅助装置的转速,末期左心衰患者可以恢复一定的运动能力。结论 CAMSIM集中参数模型符合人体血液循环特点。模型仿真结果证实了LVAD对心衰的辅助作用。     

人工心脏电动叶轮血泵动物试验及临床试用

研制的叶轮血泵在动物小公牛身上做左心室辅助存活试验，其中三头牛存活约２个月，血液生化检测表明，动物血液成分及器官功能均未有显著改变。     

HCV false positive immunoassays in patients with LVAD: A potential trap!

BackgroundLeft ventricular assist devices (LVAD) are a therapeutic choice for patients with advanced heart failure prior cardiac transplantation. Patients with a LVAD implant are frequently monitored for hepatitis C virus (HCV) as a positive result may be an exclusion criterion for transplantation.ObjectivesTo determine the rate of false positive results with immunoassays for HCV antibodies in a LVAD population.Study designBetween June 2011 and January 2015, HCV antibody testing using a chemiluminescent immunoassay (CLIA) (Liaison, Diasorin) was performed for 32 patients prior and post LVAD implantation. A HCV reactive result by CLIA was repeated and further tested by an enzyme linked fluorescent assay (ELFA) (VIDAS, bioMérieux). For patients with a positive HCV CLIA and ELFA test, immunoblot and HCV RNA detection were performed.ResultsPrior to LVAD implantation, all patients showed a negative HCV serology. After LVAD implantation, 19 patients (59%) had positive results for HCV antibody using CLIA and ELFA technologies. The HCV immunoblot was negative for 17 patients and indeterminate for two patients. For 15 patients, HCV RNA detection was performed and was undetectable. Actually, no HCV infections were observed among those who were tested for HCV RNA.ConclusionsHCV serological tests routinely used in our laboratories are not reliable in patients with cardiac devices. A positive CLIA and/or ELFA reaction in patients with a LVAD should be confirmed by HCV immunoblot and by HCV RNA PCR detection in order to rule out a HCV infection.     

Development of Terumo implantable left ventricular assist system (T-ILVAS) with a magnetically suspended centrifugal pump

The research group of Terumo, NTN, and the Setsunan University have been developing an implantable left ventricular assist system (T-ILVAS) featuring a centrifugal blood pump with a magnetically suspended impeller (MSCP). The present study describes recent progress in the development of the T-ILVAS, focusing on ex vivo and in vivo evaluations of the prototype MSCP. The MSCP is composed of four parts: a magnetic bearing, an impeller, a housing, and a DC burshless motor. The impeller is suspended by a magnetic bearing, thus providing contact-free rotation of the impeller inside the pump. The prototype MSCP was placed paracorporeally in three sheep and implanted intrathoracically in two sheep to evaluate its long-term durability and nonthrombogenicity. One sheep implanted ex vivo with the paracorporeal MSCP (Model I) survived for 864 days without any mechanical failure or thromboembolic complications, and with negligible hemolysis. The implantable Model II pump was evaluated ex vivo in two sheep and intrathoracically implanted in one sheep. These experiments were terminated 70, 79, and 17 days after implantation due to mechanical failure caused by blood leakage through the intrahousing connector of the Model II pump. However, there was no intradevice thrombus formation in any of the retrieved pumps. The dual connector system was then introduced to the Model II pump (the modified Model II), and the pump was intrathoracically implanted in a sheep. The sheep survived for more than 14 months without major complications, and the study is being continued. The preliminary chronic animal experiments demonstrated improved durability and nonthrombogenicity of the MSCP, with a low hemolysis rate for up to 864 days. Thus, the MSCP has significant potential for longterm application as an implantable circulatory assist system. Further developments toward a totally implantable system, including an implantable controller and a transcutaneous energy/information transfer system, are under way.     

CH-VAD动物实验抗凝管理研究

VAD绵羊模型常用来验证装置血液相容性、生物安全性和工作可靠性以及对动物生理状态的影响,且需要有效、安全的抗凝管理方案,以降低血栓和出血风险.研究拟讨论绵羊植入CH-VAD后应用肝素和华法林钠的抗凝效果,为后期动物长期存活实验和临床应用提供抗凝数据.选择健康绵羊6只,构建动物左心室→心室辅助装置→降主动脉血流旁路,建立CH-VAD动物模型.术中一次性静脉注射肝素250 U/kg.术后前4d连续静脉滴注肝素50 U/kg·h,使活化全血凝固时间(ACT)和活化部分凝血酶时间(aPTT)1.5～2.0倍于基值.术后第3d开始口服华法林钠,并调整用量使国际标准化比值(INR)在1.2～2.0目标范围内.动物存活期间密切观察有无出血并发症.实验终止后,观察血泵内部、人工血管、吻合口等血液流道内有无血栓.宏观检查主要脏器是否充血、梗死,取典型部分做HE染色,观察组织病理学变化.6例绵羊整个实验过程无严重出血并发症.绵羊模型术中ACT值为(326±33)s.术后前4 d ACT基本保持在(157 ±28)s,在基值的1.5-2.0倍内,aPTT上升缓慢,第4d刚达到目标范围下限.除Sheep4血泵转子背部有小块纤维组织外,其他血泵泵体、出入口、人工血管、吻合口内均无血栓和纤维组织.病理学检查显示在此抗凝方案下绵羊终末期器官基本没有血栓、坏死和微栓子存在.CH-VAD绵羊模型中,植入后初期连续静脉滴注肝素保持ACT 1.5～2.0倍于基值、后期口服华法林钠使INR值在1.2～2.0范围内能够很好的控制血栓和出血并发症,可以作为CH-VAD后期动物实验抗凝方案参考.     

Animal models of pulmonary hypertension due to left heart disease

Pulmonary hypertension due to left heart disease (PH‐LHD) is regarded as the most prevalent form of pulmonary hypertension (PH). Indeed, PH is an independent risk factor and predicts adverse prognosis for patients with left heart disease (LHD). Clinically, there are no drugs or treatments that directly address PH‐LHD, and treatment of LHD alone will not also ameliorate PH. To target the underlying physiopathological alterations of PH‐LHD and to develop novel therapeutic approaches for this population, animal models that simulate the pathophysiology of PH‐LHD are required. There are several available models for PH‐LHD that have been successfully employed in rodents or large animals by artificially provoking an elevated pressure load on the left heart, which by transduction elicits an escalated pressure in pulmonary artery. In addition, metabolic derangement combined with aortic banding or vascular endothelial growth factor receptor antagonist is also currently applied to reproduce the phenotype of PH‐LHD. As of today, none of the animal models exactly recapitulates the condition of patients with PH‐LHD. Nevertheless, the selection of an appropriate animal model is essential in basic and translational studies of PH‐LHD. Therefore, this review will summarize the characteristics of each PH‐LHD animal model and discuss the advantages and limitations of the different models.     

Surgical Treatment for Severe Heart Failure: Recent Progress in Treatment Strategy and its Present Status in Japan

Chronic intractable heart failure that is unresponsive to maximum medical therapy can have a wide variety of causes; these include advanced valvular diseases and severe myocardial ischemia, ischemic cardiomyopathy (ICM) in heart failure following extensive myocardial infarction, chronic heart failure due to dilated cardiomyopathy (DCM) in which the myocardium itself is progressively damaged or the acute aggravation of the latter. Heart transplantation has long been considered the only useful treatment for patients with heart failure due to ICM- and DCM-induced severe left ventricular hypofunction. However, because of the extremely limited number of heart transplant donors, other surgical treatments have also been attempted. In this communication, we provide an overview of the current situation with regard to left ventriculoplasty and heart transplantations, as well as of the treatment of severe heart failure using ventricular assist devices, which have recently shown remarkable progress.