Moth-eaten like impact of automated titanium fasteners on aortic valve bioprosthesis: a word of caution.

A 78-year-old patient underwent his third biological aortic valve replacement (25 mm, Inspiris Resilia™, Edwards Lifesciences LLC, Irvine, CA, USA) with COR-KNOT® (LSI Solutions, Victor, NY, USA) due to valve degeneration in 2018 at a foreign hospital. In 2021, the patient was diagnosed with severe aortic regurgitation and admitted to our hospital for his fourth surgery. Intraoperatively, a total of 7 perforations in all 3 valve leaflets have been observed, which were obviously induced by the rigid metallic fasteners. Redo isolated aortic valve replacement (29 mm, Perimount Magna Ease, Edwards Lifesciences LLC) was performed with conventionally knotted, pledget enforced braided threads. Postoperative course was uneventful. This report shows that COR-KNOT-induced defects do not appear immediately after surgery but within the first 4 postoperative months. Since failure of aortic bioprostheses due to aortic insufficiency is often rated as 'early degeneration' and degenerated aortic bioprostheses are mostly replaced by valve-in-valve strategy, the true incidence of this serious complication might be underestimated. COR-KNOT should be used with caution in biological aortic valve replacement and patients should undergo close postoperative follow-ups.