We report two cases of newborns with critical pulmonary stenosis having intact ventricular septum, who underwent pulmonary valve balloon valvuloplasty followed by banding of a patent ductus arteriosus. Transcatheter pulmonary valvuloplasty was performed one week after delivery. Following the procedure, both developed "circular shunting" as a consequence of left-to-right ductal flow and pulmonary regurgitation. This in turn caused increased blood flow into a dysfunctional right ventricle and low systemic cardiac output syndrome. The PDA banding was performed urgently as a rescue measure in order to restore systemic flow while still maintaining some duct-dependent pulmonary blood flow. This approach resolved the circular shunting. Outcome was favorable in both the patients.
Keywords: emergency surgery; patent ductus arteriosus; pulmonary stenosis; shock.