Anatomo-pathological analysis after CoreValve Revalving system implantation

Aims: Significant technological improvements have made percutaneous aortic valve replacement (PAVR) simpler and safer, but the behaviour of the implanted valve over time remains unknown. We report the anatomo-pathological analysis of patients who died at different time intervals post PAVR with the Core Valve Revalving System. Methods and results: In our early experience, 21 patients underwent Core Valve implantation between 12/2005 and 02/2007. Among the 11 deaths at one year follow-up, four patients had an autopsy with macro and microscopic analysis. The device was divided in three parts during pathological assessment: the lower portion (area 1), the leaflets (area 2) and the upper part (area 3). The Core Valves were implanted for 3, 13, 104 and 350 days. Gross examination showed neointimal tissue covering most of the frame struts in contact with the aortic wall, but areas of high velocity blood flow were bare. Histopathology examination demonstrated fibrin deposition and inflammatory response early after valve implantation, followed by neointimal coverage with progressive regression of the inflammatory response over time. Conclusions: While waiting for results of longer term PAVR echocardiographic follow-up, the anatomic assessment is encouraging with neointimal coverage of the native valve site and no excessive pannus formation occurring over the valve leaflets.