| ObjectiveCongenital heart diseases ( CHD) are the most common pediatric heart diseases. It's estimated that 150,000 children with this kind of disease were born in China per year. Among them about 21.4% are atrial septal defec (ASD) patients, Of which secundum atrial septal defect are occupyiny majority. In the past, surgical repair was the on-ly method to solve the problem. Since King did animal experiment on closure of ASD successfully and proceed clinical utilization fruitfully in 1974, there have emerged several kinds of closure devices in western countries. But these devices have not been widely used in china be-cause of the expensive price. Our experiment was to utilize a new do-mestic TiNi memory alloy closure device in a canine model, evaluate the closure effect and the reaction of histology of the closure device, make a primary feasibility study of it and direct further clinical experi-ment.Materials and Methods Materials1. Animals: six canines, weight 20 Kg.2. Closure Device; domestic TiNi memory alloy closure device.3. Apparatus and Medicine: (l)ECG, BP monitor.(2) respirator.( 3 ) Antibiotic: Penicillin.(4) Anticoagulant; heparin calcium.( 5 ) Platelet inhibitor: Aspirin.(6)Anesthetic, Calmative: Ketamine, Diazepam.(7)Plasma substitute and Operating rescue medicines. MethodsThe Atrial Septal Defect ( ASD) models were established by ASD stoma and closed by a new domestic TiNi memory alloy closure de-vice. Pathologic study was performed at four hours, fifteen days, one month, two months, three months after device implantation to observe closure effect and the heart were removed for autopsy and light micro-scope, electron microscope examination.ResultsThe ASD models were successfully established in five dogs. The procedures were technically successful in five dogs. The device were covered by a smooth and glistening organization which was conformed to be fibrous neoendothelium by light microscope and electron micro-scope.DiscussionThe Atrial Septal Defect ( ASD) is one kind of most common Congenital heart diseases ( CHD) . Among them secundum atrial sep-tal defect are occupyiny majority. Surgical repair was the only method to solve the problem at before. Since King did animal experiment on closure of ASD successfully and proceed clinical utilization fruitfully in 1974, there have emerged several kinds of closure devices in westerncountries, such as Double -Disk Occluder(Rashkind) , Buttoned Oc-cluder( Sideris) , Cardio - Seal Occluder and Amplatzer Occluder. These devices have some clinical effects though they have many limita-tions as well. Furthermore, these devices have not been widely used in china because of the expensive price. Based on these reasons, we designed a new domestic TiNi memory alloy closure device. And we make a primary feasibility study of it and direct further clinical experi-ment through animal experiment (canine).Domestic TiNi memory alloy closure device is consisted of two self - expandable round disks made of TiNi memory alloy wire mesh structure filled with Dacron fabric that are linked together by a short connecting waist. Nitinol wire( Ni 50% and Ti 50% ) s diameter is 0. 15mm. Weaving single ?thread double ?disks closure device, for-matting in 550 Tl by 30 min, pickling, polishing, sanitizing after cool-ing. Feasible bio - consistency, fluid interdictability and good retriev-ability make this device a realistic bio - metal - material, which been widely used in interventional device. Its principle is to block blood stream by Dacron fabric while using Nitinol wire as framework. Blood cell will have physiochemical reaction with the wire as time goes by. At last, it will block the abnormal blood stream eventually. So it has more realistic effect.The ASD models were successfully established in five dogs and the closure procedures had been technically successfully. The devices were covered by a smooth and glistening organization which was con-formed to be fibrous neoendothelium by light microscope and t... |
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