Objective To compare simulated training of "45° tilting insertion" and the "dynamic scan" needling under B ultrasound.Methods Fifty volunteer residents and visiting physicians worked in the anesthesiology department in Peking Union Medical College Hospital were recruited to attend the simulated needling training.The insertion time,insertion attempts until success,numbers of success while advancing the needle and numbers of needle tip visible upon success were re corded.The degree of difficulty and safety of the techniques,the confidence of performing the techniques,the clinical usefulness of the techniques and the training effect were evaluated among the volunteers.Results There were no differences in the insertion time,numbers of successful insertion while advancing the needle and numbers of needle tip visible upon success between the two techniques.Compared with "45° tilting insertion" technique,"dynamic scan" resulted in less needle redirection times and a higher first-attempt successful rate,and got higher scores in terms of difficulty and safety (P＜0.05 or P＜0.01).The confidence scores of performing the two technique were similar.20 (40％) volunteers chose to use "dynamic scan",8 (16％) chose to use "45° tilting insertion" and 22 (440％) chose to use both technique in their clinical work.100％ of them considered the training was greatly helpful or helpful.Conclusion The technique of "dynamic scan" produced a higher first-attempt successful rate and was easier and safer than "45° angle insertion".The combination of the two techniques might be a new technique that is worth trying.

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