# Severe Mitral Stenosis and Regurgitation Due to Bioprosthetic Valve Failure with Massive Pannus

## TL;DR

A 76-year-old woman with a failed bioprosthetic mitral valve and severe pannus overgrowth required open surgery due to the infeasibility of less invasive treatments.

## Contribution

Demonstrates the limitations of transcatheter valve-in-valve in cases of extreme pannus overgrowth and highlights the need for open surgery.

## Key findings

- Pannus overgrowth reduced the valvular opening to a pinhole, making transcatheter treatment infeasible.
- Open surgical replacement was necessary due to the extent of bioprosthesis deformation and pannus coverage.
- Macroscopic and microscopic examination revealed accordion-like leaflet deformation on the ventricular side.

## Abstract

Bioprosthetic valve failure after mitral valve replacement is a well-recognized phenomenon, with pannus overgrowth being one notable cause. The standard treatments include redo surgical mitral valve replacement and the less invasive transcatheter treatment, mitral valve-in-valve. However, the feasibility and safety of performing mitral valve-in-valve when pannus overgrowth has reduced the valvular opening to a mere pinhole remains uncertain.

A 76-year-old woman, who had previously undergone mitral valve replacement, was admitted for congestive heart failure. Severe mitral stenosis and severe mitral regurgitation were diagnosed using transthoracic echocardiography. During redo mitral valve replacement, we observed that the prosthetic valve leaflets on the left atrial side were almost entirely covered with pannus tissue, leaving only a central pinhole for blood flow. Macroscopic and microscopic examination of the bioprosthesis revealed accordion-like leaflet deformation on the ventricular side.

Although the transcatheter valve-in-valve procedure is recognized as a less invasive treatment option for degenerated biological valves, in certain cases such as ours, open surgery becomes imperative as the most appropriate treatment.