Early structural valve deterioration of balloon expandable transcatheter aortic valve leaflets due to intrinsic and extrinsic nodular calcifications in a haemodialysis patient: a case report

Abstract

Background: Several reports have shown that transcatheter aortic valves are comparable in durability to surgical aortic valves. However, early structural valve deterioration (SVD) is rarely reported to occur, especially in haemodialysis patients.

Case summary: We present a case of rapidly progressive bioprosthetic aortic valve stenosis in a patient with end-stage renal disease secondary to diabetic nephropathy in an 83-year-old female admitted due to progressive dyspnoea and orthopnoea. A 23 mm sized SAPIEN3 bioprosthetic aortic valve showed normal function for the first year after transcatheter aortic valve implantation (TAVI), but then rapidly developed stenosis and required acute hospitalization for heart failure a year and a half after surgery. Emergent surgical aortic valve replacement with a 19 mm On-X valve (CryoLife, Kennesaw, GA, USA) was performed. Pathological examination of the explanted SAPIEN 3 valve demonstrated severely degenerated bioprosthetic pericardial leaflets with severe intrinsic and extrinsic nodular calcifications, which could limit the leaflet motion.

Discussion: There is a lack of reports on the long-term procedural outcomes of TAVI in haemodialysis patients. The development of SVD in patients undergoing dialysis is multifactorial and has yet to be fully elucidated. In the presented case, the removed TAVI valve had severe extrinsic calcified nodules alongside a fibrin thrombus. Considering these pathological findings, antithrombotic therapy to prevent fibrin thrombus from adhering to the TAVI valve may be important to avoid early SVD.

Keywords: Aortic valve stenosis; Case report; End-stage renal disease; Structural valve deterioration.

Figure 1

Contrast-enhanced computed tomography of the implanted TAVI valve (SAPIEN3) and representative histopathological images of the removed TAVI valve. Contrast-enhanced computed tomography showed severe calcification and thickening in all three prosthetic valve leaflets. (A) The removed TAVI valve showed adherence of nodular calcification in all tricuspids. (B and C) Gross images of explanted SAPIEN3 valve showing nodular calcification protruding to the aortic side of the leaflets. Low-power and high-power images of leaflet 1. (D and E) There is a severe leaflet extrinsic calcification containing calcific nodules and fibrin deposition. The surface of the leaflet is intact, and the border is easily recognized (red arrows). Low-power and high-power images of leaflet 3. (F and G) The leaflet is severely thickened and composed of intrinsic and extrinsic nodular calcifications. Yellow arrows indicate the separation of the leaflet collagen fibres, and intrinsic nodular calcification is observed between these fibres.