浸冷式心脏外科冷刀的研制及应用实验

Development and Experiment Studies of Aprecooled Cardiosurgical Cryoknife

为适应心律失常外科治疗的需要，作者设计了浸冷式心脏外科冷刀，并对其进行了物理性能检测、动物实验及临床电生理实验等。冷刀刀身用以贮冷，贮冷能力与其材料及物理性能有关。实验冷刀置于猪右心室，刀身温度可在－５０℃以下保持５分钟以上，对厚４（３）ｍｍ的离（在）体心肌冷冻温度可保持在－２０℃以下１分钟以上。心耳冷冻后３０分钟见心肌细胞和间质水肿。实验证实该冷刀具有阻断心肌电传导作用，可作为心律失常外科的治疗手段之一。

For the requirement of cardiac arrhythmia surgery,theautbors designed a new type of precooled cardiosurgical cryoknife(PCSC ).Its basic structure is presented and its physical nature was examinied.In vitro and in vivo experiments ation morphologic changes of tissues and clinical electro physiology studies were carried out.The onyoknife is composed of head,body,handle and a covering net protectim.The body of PCSC served as cold storage with a that is closely related to the quality and physical property of the body.When PCSC was put on the epicardium of right ventricle,PCSC’s body could maintain a temperature below-50℃ for 5 minutes. The experiments of freezing myocardium demonstrated that the myocardical temperature of various parts 4 mm in thickness in vitro and 3 mm in vivo with cardiopulmonary bypass could lower down to below-20℃for longer than l minute.Thirty minutes of application of PCSC at the right atrial appendage,pathologic sections of aight atiial tissue atthe site of application showed adema of the myocytes and interstitia.The studies demonstrated that electrical conductivity of myocardium could be restrained by freezing with PCSC and it could be used as one of methods of surgical treatments of cardiac arrhythmia.