Self-Expandable Harmony Valve Implantation in Supravalvular Pulmonary Position After Senning Procedure: A Case Report

Transcatheter pulmonary valve implantation has emerged as a minimally invasive therapeutic strategy for the management of right ventricular outflow tract dysfunction, particularly in patients considered unsuitable for repeat surgical intervention. Implantation of the self-expandable Harmony valve represents a therapeutic option for patients with large right ventricular outflow tracts that are unsuitable for balloon-expandable devices. However, significant anatomical variability, particularly in patients following the atrial switch procedure, poses procedural challenges and underscores the importance of meticulous pre-procedural planning. A 44-year-old male with Transposition of the Great Arteries underwent a Senning-Brom procedure in infancy, followed by surgical correction of a baffle leak and pulmonary valve reconstruction at the age of 22. Over time, he developed progressive severe pulmonary regurgitation, confirmed by serial MRI, showing worsening regurgitant fraction (44%) and significant left ventricular (subpulmonic) dilation. The pre-procedural CT screening report for the Harmony valve (TPV25) revealed complex LVOT anatomy, with adequate proximal anchoring but suboptimal distal oversizing. Despite complex anatomy and suboptimal distal oversizing, the procedure was undertaken based on the anatomical dimensions of the main pulmonary artery, favorable proximal anatomy, and a safe distance from the coronary arteries. The procedure was performed via femoral access, and the valve was advanced into the pulmonary artery and deployed in a controlled, stepwise manner at a high level of the bifurcation. Final angiography confirmed stable positioning, optimal anchoring, and complete resolution of pulmonary regurgitation, with preserved coronary flow and no evidence of compression, indicating a successful outcome. This case demonstrates that Harmony valve implantation in a supravalvular pulmonary position is feasible in patients with Transposition of the Great Arteries following atrial switch repair, despite complex anatomy and suboptimal distal oversizing, when the procedure is guided by comprehensive multimodality imaging and adapted implantation strategies.