The study of dry biological valve crosslinked with a combination of carbodiimide and polyphenol

The glutaraldehyde crosslinked pericardium has been used in bioprosthetic valves for about 50 years.However,problems such as glutaraldehyde residue and calcification still exist in current commercial products.Non-glutar aldehyde crosslinked dry valve is an important strategy to solve those problems.In this study,a non-glutaraldehyde crosslinked dry biological valve material was obtained by the combined crosslinking of carbodimide(EDC)and polyphenol.The results showed that the comprehensive properties of EDC and curcumin crosslinked pericardium were superior to glutaraldehyde crosslinked pericardium,including unfolding property,anti-calcification,cytotoxicity,anticoagulant properties,mechanical properties,enzyme degradation resistance and thermal shrinkage temperature.EDC and curcumin crosslinked dry pericardium could flatten after being folded at 40℃ for 3 days while glutaraldehyde crosslinked pericardium could not.The calcification of pericardium treated with EDC and curcumin was 1.21±0.36 mg/g in rats after 60 days'subdermal implantation,much lower than that of glutaraldehyde treated control group(22.06±3.17 mg/g).

Relationship between heart rate and failure of biological valve： slowing the heart rate could delay the failure of biological valve？

For the patients with a relatively slow heart rate, the frequency of opening and closing of biological valves and the number ot impact ot mecnamcai stress upon biological valves were relatively less, so the mechanical wear was reduced. The question is whether this can slow the failure and calcification of the biological valve. A retrospective analysis replacement （MVR） cases was carried out. of 92 biological mitral valve during the period of 1996-2003

Prosthetic heart valves for transcatheter aortic valve replacement

Transcatheter aortic valve replacement (TAVR) has the advantages of less trauma and faster postoperative recovery, which has brought the possibility to the elderly patient with valvular heart disease and is gradually replacing surgical aortic valve replacement (SAVR). The interventional valve used in TAVR needs to be compressed and transported through the catheter to the lesion site, and can still recover its original shape, structure and performance. This process requires that the material should be flexible, and the rigid mechanical valves in SAVR are not suitable. Recently, decellularized biological valves have been widely used in clinical practice, but their poor durability causes a limitation for long-term implantation. Therefore, the anti-calcification modification of biological valves and the design of new polymeric valves with good biostability have gained considerable attention. This review summarizes the calcification mechanism of biological valves and the research progress in anti-calcification modification strategies. Besides, the development of new polymeric valves is included, with special attention to representative cases, such as polysiloxane, polytetrafluor- ethylene, poly(styrene-block-isobutylene-block-styrene), and polyurethane- based materials. Finally, the challenges and future perspectives of artificial heart valve materials are discussed.

Median mitral valve technique in the second trimester with zero contrast intraoperative nursing

Summarized a case of intraoperative nursing experience in a second-trimester patient with mitral bioprosthetic valve destruction undergoing median mitral valve technique with zero contrast agent.In this case,a patient with 18 weeks of intrauterine pregnancy after artificial insemination,who had a sudden palpitation,was sent to the hospital in an emergency and diagnosed with severe intravalvular regurgitation and severe pulmonary hypertension after mitral artificial biological valve replacement.A treatment plan was developed after the systematic and comprehensive evaluation of the condition of the patient under a multi-disciplinary combination.Intraoperative nursing cooperation,patient condition monitoring,fetal X-ray protection,prevention of massive bleeding,sudden arrhythmia,and other emergency rescue cooperation were implemented in the processing of surgery,and no intraoperative nursing complications occurred.The patient recovered and was discharged from the hospital.The pregnancy was terminated by cesarean section after full term and the newborn survived with no deformity.