La disfunción protésica que puede ser causa de una situación urgente incluye: 1) dehiscencia protésica; 2) estenosis protésica que puede ser debida a trombosis protésica o a paño valvular (crecimiento de tejido fibroso desde el anillo de la prótesis a su orificio de entrada, también conocido como pannus)
https://secardiologia.es/images/publicaciones/libros/2009-se...

Bioprosthetic heart valves undergo tissue deteriorationcharacterized by tissue degeneration, calcifications, cusptears, and sometimes fibrous pannus. Pannus is composed offibroblasts and collagen fibers, which reflect tissue reaction atthe site of implantation.

However,most of the time, collagen extension remains limited near thering, and extensive pannus in-growth, especially in thebioprostheses mitral site, is an uncommon cause of valvefailure.

Pathology examination confirmed the extensive pannus ingrowth without thrombus or endocardial damage (Figure 3). Cultures were negative.

https://www.ahajournals.org/doi/pdf/10.1161/CIRCULATIONAHA.1...



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Note added at 29 mins (2020-04-30 12:00:04 GMT)
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From the same English ref, Figure 2:
"The fibrous pannus covers the ring and extends onto the prosthesis orifice" - which is very similar to the definition given in the Spanish ref above.