Heart Valve Diseases ; therapy ; Heart Valve Prosthesis Implantation ; methods ; Humans

Aortic Valve Stenosis ; surgery ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; methods ; trends ; Humans

Age-related degenerative calcification is currently the most common cause of aortic stenosis (AS) in adults and the most frequent reason for aortic valve replacement in patients with AS. With the increased life expectancy, a large proportion of elderly patients with AS is undergoing cardiac surgery, although many are not offered conventional aortic valve replacement due to the risks involved. However, sutureless aortic valve replacement provides an alternative for this group of elderly patients. This case series reports the first experience in Asia of sutureless aortic valve implantation in seven patients at our institution.
Aortic Valve Stenosis ; epidemiology ; surgery ; Asia ; epidemiology ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; methods ; Humans

OBJECTIVETo evaluate the feasibility and short-term results of transcatheter aortic valve implantation (TAVI) using a new transcatheter valve.

METHODSTwenty healthy adult sheep received general anesthesia. Under the guidance of X-ray and transthoracic echocardiography (TTE), the new anti-calcification transcatheter valve was released from delivery system and implanted at the level of native aortic annulus via left common carotid artery. Position and function of the new anti-calcification transcatheter valve were evaluated by angiography and TTE immediately after intervention. Thirty day survival rate of animals was obtained.

RESULTSNew transcatheter valves were implanted in all sheep. Fifteen sheep (75%) survived up to 30 days and post-operative examination showed that the transcatheter valve was in optimal position without migration and mitral valve impingement. The native coronary artery was patent in these animals. There was a slight paravalvular leak in 5 sheep. Postoperative echocardiography showed reflux percentage was significantly increased (P < 0.05) compared pre-intervention. Effective orifice area, aortic systolic pressure, diastolic aortic pressure, mean aortic pressure, left ventricular systolic pressure, left ventricular end diastolic pressure and heart rate were similar between post and pre-intervention (all P < 0.05). Five sheep died after TAVI within 30 days, including one fatal ventricular fibrillation occurred immediately after releasing the transcatheter valve and another sheep died of acute myocardial infarction due to left main coronary artery occlusion evidenced by angiography. Two sheep died of severe mitral regurgitation at 8 and 12 hours post-operation and one died of infective endocarditis at 26 days after intervention.

CONCLUSIONOur favorable preliminary results showed that it was feasible to perform TAVI using the new transcatheter valve.

Animals ; Aortic Valve ; surgery ; Aortic Valve Stenosis ; surgery ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; methods ; Sheep ; Treatment Outcome

OBJECTIVEThe purpose of this study was to determine the feasibility of transcatheter pulmonary valve replacement in sheep up to 6 months post procedure.

METHODSFresh sheep pericardium treated with a 0.6% glutaraldehyde solution for 36 hours was sutured to a valvular ring and then fixed onto a newly designed nitinol self-expandable stent. Thoracotomy was performed in sheep (23.5 +/- 3.1) kg under general anesthesia and the device was delivered into the native pulmonary valve of the sheep via the anterior wall of right ventricle by catheter and fooled for 6 months.

RESULTSOne sheep died 4 months after the procedure due to in-stent thrombosis. Another 4 animals survived the 6-month observing period. Angiographic and hemodynamic measurements confirmed good positioning and function of the stents with a competent valve immediately post procedure and 6 months post the procedure in surviving animals.

CONCLUSIONImplantation of the nitinol self-expandable stent in the pulmonary valve position by a transcatheter approach is feasible and good function of transcatheter implanted memory nitinol valved stents was shown after 6 months of implantation in sheep.

Animals ; Disease Models, Animal ; Female ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; instrumentation ; methods ; Male ; Pulmonary Valve ; surgery ; Sheep ; Stents

Aortic Valve/surgery* ; Aortic Valve Stenosis/surgery* ; Cardiac Catheterization/methods* ; Heart Valve Prosthesis ; Heart Valve Prosthesis Implantation ; Humans ; Transcatheter Aortic Valve Replacement/methods* ; Treatment Outcome

Aged, 80 and over ; Heart Valve Prosthesis Implantation ; methods ; Humans ; Male ; Prosthesis Failure

OBJECTIVETo evaluate the feasibility and effectiveness of transcatheter transapical implantation of a new domestic balloon-expandable bioprosthetic aortic valve in goats.

METHODSWe developed a new tube-like balloon-expandable bioprosthetic aortic valve which was made from cobalt-chromium alloy and bovine pericardium. Briefly, fresh bovine pericardium was trimmed into artificial leaflets and sutured into the cobalt-chromium alloy stent by hand post cell extracting and anti-calcification treatments. A left anterolateral mini-thoracotomy was performed in the 5(th) intercostal space of 5 goats. After opening the pericardium, the apex of the left ventricle was punctured, a stiff guidewire was positioned across the aortic arch and anchored in the descending aorta. The delivery catheter (22 F) was then introduced through the stiff guidewire into the aorta arch under fluoroscopic guidance. After correct valve position was confirmed by digital subtraction angiography, the valved stent was implanted after rapid inflation of the balloon. The immediate results of implanted valved stents were evaluated with angiography and echocardiography.

RESULTSFour devices were successfully implanted into aortic valve position of goats and one goat died of severe aortic valve regurgitation because the valved stent was implanted below the normal position.Immediate observation after procedure in 4 goats by angiography and echocardiography showed that the valved stents were in the desired position after implantation. Mild paravalvular leakage were found in 3 out of the 4 survived goats and there were no moderate to severe aortic regurgitation in survived goats.

CONCLUSIONThe procedure of transcatheter transapic aortic valve implantation with our new-type domestic balloon-expandable valved stent and delivery system is feasible and effective.

Animals ; Aortic Valve ; Catheterization ; Cattle ; Female ; Goats ; Heart Valve Prosthesis Implantation ; instrumentation ; methods ; Male ; Stents

Aortic Valve ; surgery ; Cardiac Catheterization ; Heart Valve Prosthesis Implantation ; methods ; Humans

OBJECTIVEThe aim of this study was to identify the long-term character of the domestic bileaflet mechanical valve in the chronic implanted sheep model and to evaluate the potential value of the modal.

METHODSSix adult sheep underwent implanted mechanical bileaflet valve in pulmonary position under the cardio-pulmonary bypass with beating heart. The chronic implanted sheep model was built up and observed in the respects of a long-term survival, function of prosthesis and pathological specimen.

RESULTSSix adult sheep survived with good condition after operation. The average survival period of six sheep was (221 +/- 208) days. Two sheep were postoperatively sacrificed in 41 and 71 days, respectively. The necropsy revealed normal valve function without thrombosis, periprosthetic leakage and overgrowth of fibrous tissue. One sheep died from dysfunction of prosthetic valve at the postoperative 196 days. The reason was the prosthetic thrombosis with slight overgrowth of fibrous tissue in periprosthesis. The other two sheep died from severe anemia at the postoperative 196 days and 234 days, and the autopsy revealed no abnormal finding else. And one remained to survive with good condition up to now (over 617 days) and was checked by Doppler echocardiogram twice at the postoperative 438 days and 479 days, respectively. The results showed normal function of the bileaflet valve in pulmonary position.

CONCLUSIONThe long-term good effects would be achieved by using the implanted new domestic bileaflet valve in pulmonary position of sheep.

Animals ; Heart Valve Prosthesis Implantation ; methods ; Male ; Models, Animal ; Pulmonary Valve ; surgery ; Sheep