Ventricular Septal Defect as a Bail-out Shunt in Prosthetic Tricuspid Valve Obstruction

Prosthetic valve thrombosis or obstruction is a feared complication of mechanical valve replacement. The risk is highest in the tricuspid position, with an estimated incidence of 0.7%-1.2% per patient-year, largely attributable to the low-pressure, low-flow environment of the right heart. Clinical presentation is usually acute, with symptoms of right-sided heart failure and cardiogenic shock necessitating urgent intervention. We present an unusual case of a chronic, completely stuck prosthetic tricuspid valve discovered incidentally with no hemodynamic compromise. The patient's hemodynamic stability was sustained by a preexisting ventricular septal defect, which provided an alternative pathway for systemic blood flow. This case highlights the critical interplay between complex coexisting congenital anomalies in patients with prosthetic mechanical valves.