Sideris, Rashkind occluders and spring coils have been used to seal ventricular septal defects in the past, but due to the high incidence of complications, inconvenient operation, inability to recycle at will, and narrow indications, they have not been successfully used. be promoted clinically.
In the late 1990s, AGA Pharmaceutical Co., Ltd. developed a new type of Amplatzer ventricular septal defect occluder, and successively applied for a series of U.S. patents, the most typical of which is the "prefabricated catheter-guided occlusion device" ” (US5846261), and applied for a world patent (WO9912478) through PCT. This patent application has been published in many countries. The Amplatzer ventricular septal occluder is a double-disc occluder: it consists of three parts: a self-expanding double disc and a "waist" that connects the double discs. The "waist" is short cylindrical. Both the double discs and the "waist" are made of a dense network structure made of nickel-titanium memory alloy, and the double discs are filled with polymers; the diameter of the "waist" determines the size of the VSD that can be blocked, and is divided into categories based on the diameter of the "waist" There are various models ranging from 4 to 16mm, and the double disc is 2 to 3mm larger than the diameter of the "waist". The delivery system consists of a delivery stylet, expansion tube, delivery sheath, loader, and push catheter.
In 2002, Hijazi et al. first successfully used the new Amplatzer occluder developed by AGA Pharmaceutical Co., Ltd. to treat membranous ventricular septal defect. In 2003, ThanopoulosBD et al. used this new AmplatzerVSD occluder to treat 22 cases of myoventricular septal defect and 13 cases of membranous ventricular septal defect. The success rates reached 95% and 92.3% respectively. One of the 13 cases of membranous ventricular septal defect occurred. Device embolization. In the same year, AroraR et al used different occluders to treat VSD patients, with Rashkind umbrella device (RUD) used in 29 cases, Amplatzer ventricular septal defect occluder used in 107 cases, and spring coils used in 1 case. The diameter of VSD is 3-12mm. The success rate of RUD is 86.2%, and the success rate of Amplatzer ventricular septal defect sealer is 97.1%. It has been clinically found that the Amplatzer ventricular septal defect occluder has a higher success rate than other devices.
Amplatzer occluder has the advantages of simple operation, wide adaptability and convenient recovery. It represents the highest level in this field and has received widespread attention.
The Amplatzer occluder is used to treat VSD, and the postoperative results are good. However, the occluder is expensive and has certain limitations in its widespread use in China. For this reason, the country is actively exploring the feasibility and therapeutic effect of domestic occluders in treating membranous ventricular septal defects.
Department of Cardiovascular Medicine, Xijing Hospital, Fourth Military Medical University, Zhang Yushun and others began to use domestic double-disc occluders to treat membranous ventricular septal defects in July 2002, and achieved satisfactory clinical results. Its indications are: VSD diameter 2 ~ 14mm, more than 2mm away from the aortic valve. Immediate postoperative left ventriculography in 20 cases showed slight to small shunting in 6 cases (30%), and complete occlusion in 14 cases (70%). For patients whose postoperative left ventriculography showed trace to small shunts, the left ventriculography was repeated after the occluder was released, and it was found that the trace shunts completely disappeared in 4 cases and the small shunts were significantly reduced in 2 cases. Color Doppler showed complete closure 24 hours after surgery. No residual shunt and occluder displacement was found 1 month after surgery.
The nickel-titanium alloy ventricular septal defect closure developed by Qin Yongwen and others from the Department of Cardiovascular Medicine, Changhai Hospital of the Second Military Medical University and the Shanghai Iron and Steel Research Institute is braided with nickel-titanium alloy wires and shaped into a double disk after heat treatment. shape. The central part is cylindrical, 7mm long, and the diameter of the discs at both ends is 4mm larger than the central part. The diameter of the nickel-titanium alloy wire is 0.10mm, the nickel content is 55.6%, titanium 44.4%, and the phase transition temperature is 35~40°C. There are 3 layers of polyester sheets sewn in the middle of the occluder, and 316L stainless steel ring envelopes at both ends. The front end is a blind end, and the rear end has a nut, which can be screwed with the screw of the connecting rod. There are a variety of specifications (4 ~ 12mm) available. The occluder can be retracted into the 7F sheath and can be pushed and pulled back and forth in the sheath. Once in place, release the occluder by rotating the push rod. According to a Liberation Daily report on September 10, 2003, the Cardiology Department of Changhai Hospital of the Second Military Medical University successfully treated more than 130 patients with ventricular septal defects using this self-developed nickel-titanium alloy ventricular septal occluder.
The Department of Cardiology of the Sixth People's Hospital Affiliated to Shanghai Jiao Tong University has also successfully repaired perimembranous ventricular septal defects using a domestic double-disc imitation Amplatzer ventricular septal defect occluder (Shanghai Memory New Materials Co., Ltd.).