Ординатура / Хирургия / Библиотека им академика М.И. Перельмана / Книга_3820_Библиотеки_им_академика_М_И_Перельмана

Another interesting population are patients with degenerated xenografts. While this problem is less frequent with the current generation of biologic valves, the trend for implantation in younger patient groups will generate an increasing patient cohort requiring a second operation. Redo AVR can be performed with excellent results, but alternative techniques may further decrease the risks associated with redo aortic valve surgery. Especially after root replacement, redo AVR can be challenging. A few studies demonstrated that for both mitral and aortic valve xenografts TAVR can be performed suc­cessfully. The so-called valve-in-valve concept makes useof the stent of the implanted xenograft that serves as a marker during implantation of the transcatheter valve [69–71]. This concept has also already been applied in an experimental setting as valve-in-a-ring for late mitral valve replacement after late failure of mitral valve repair [71]. Another promising approach is the transcatheter placement of autologous tissue engineered valved stents. A proof of concept has recently been demonstrated. This approach may have impor­tant implications for the correction of congenital cardiac malformations [72].