Discussion:
The Cor-knot® device is an automated titanium suture fastening device manufactured to knot and cut sutures throughout minimally invasive valve surgeries in which manual ties may be unfeasible. In addition to offering a convenient, expedited suturing solution which decreases aortic cross-clamp and cardiopulmonary bypass time, the Cor-knot® system has been shown to be just as durable, if not more durable, than manually hand-tied sutures2. Though shown to be a safe, viable alternative to manual knot-tying, long-term complications of the fastening device remain poorly understood. The St. Jude Trifecta® aortic bioprosthesis was implemented in our patient in 2015; recent data has demonstrated this valve has necessitated reintervention more often than other bioprostheses3. Whether the durability of the Trifecta® valve contributed to the perfectly round perforations in both leaflets is unable to be determined, but it can be presumed that bioprosthetic valve deterioration may have had a role. Severe transvalvular aortic regurgitation after implementation of a Trifecta® (St. Jude, Inc.) prosthesis in conjunction with the Cor-knot® has been scarcely reported. Several reports exist demonstrating severe bioprosthetic transvalvular regurgitation from a similar causative mechanism in other SAVR prostheses, though the patients within these reports presented within 20 months of valve replacement4,5. As highlighted within these reports, we believe the mechanism of leaflet failure in our patient was due to repetitive trauma suffered by the leaflet as it consistently flapped against the Cor-knot®.
Conclusion :
Our report serves to highlight an underreported and poorly understood mechanism of bioprosthetic aortic regurgitation secondary to leaflet trauma from an automated titanium fastening device. We recommend operators to remain vigilant of this complication before utilizing artificial knot-fastening systems and to orient knots away from imposing neighboring leaflet impedance.