The Experimental Research Of Percutaneous Transmuyocardial Laser Revascularization Treating Animal Model Of Ischemic Myocardium

Title:The experimental research of percutaneous transmyocardial laser revascularization treating animal model of ischemic myocardium Objective: TMR has been used clinically to treating patients with end-stage coronary heart disease that is not amenable to PTCA or CABG for several years.Because of the diffuse nature of their disease,these patients experienced severe angina refractory to medical management. Although there are more reports of angina relief and quality of life enhancement,the invasive TMR by a thoracoscopic technique has a high mortality and morbility rate during periprocedural. In recent three years PMR has been reported to have similarly symptomatic improvement excluding the above complications.One side a ramdomized multicenter clinical trial were proceeding to verifying its validity and safety,on the other side whether PMR has the protective effects of ischemic myocardium and what its undisputed mechanism is are still unknown. The purpose of our research is to roughly probe into the problem by the treatment of PMR to ischemic myocardial animal model. Methods:Ischemic myocardial animal model. 22 hybridia heathy caines hearts were exposured through a thoracotomy in meso-position and the anterior descending branch being 2?cm apart from its inflow aditus were dissociated and ligated until its blood flow didn?t change. At the same time its homologus collateral coronary arteries were also ligated. Standard being selected of the research is as follows:(iDthe degree of LAD stenosis showed by CAG is about 90%;@i)the imagines of blood perfusion and metabolism of ischemic myocardium showed by SPECT and PET are not matching. I. Experimental research of PMR treating ischemic myocardium. 22 caines conforming to the research situations were divided into two groups:treatment group(n4 7) and control group(n5). The former was observed in four time points such as 24?hour. l week . 1 month and 3拁? month after procedural,while the latter in three time points such as I ~ week I month and 3?month. The ischemic myocardium were irradiated by Ho:YAG laser from MLAS-l system made in Cardial Genesis Corporation of Us. 2. The procedure of PMR. A 9F sheath was positioned in one femoral artery and a 9F guiding catheter carrying 6F laser catheter was advanced across the aortic valve and positioned in the left ventricle.A 6O0left anterior oblique and a 300 right anterior oblique ventriculogram were recorded.The laser catheter was advanced to the wall of the left ventricle and deflected to position it against the wall to be lased.The laser was set to deliver 2W through the 1-mm optical fiber in a series of 2? sequential pulses. Average 18 ?2 laser channels were made per caine heart.A Electrocardiograph was recorded and movement of the catheter was monitored within the procedure .The position and serial number of laser channels were marked on screen to avoid repeat irradiation in the same place and assure the equality of channels.Control group were only observed. 3. Observation items. (DSingle photon emission computed tomography:32 imagines were collected by injecting mTcsestmibi 15 5mCi into vessel in 24?hour 1 week 1 month. 3st month after the PMR technique. The blood perfusion and metabolism of lased myocardium were evaluated by the method of 4? mark in 8 myocardium section. ?Ultrasound cardiography:the myocardial stru...