Mechanisms of tricuspid regurgitation in patients with hypoplastic left heart syndrome undergoing tricuspid valvuloplasty

Objectives: Tricuspid regurgitation (TR) remains a risk factor for morbidity and mortality through staged palliation in patients with hypoplastic left heart syndrome (HLHS). Reports on the mechanisms associated with TR in patients with HLHS are limited. Thus, we sought to describe our experience with tricuspid valve (TV) repair in these patients, focusing on the mechanisms of TR and corresponding surgical techniques. Methods: We performed a retrospective single-center review (January 2000 to December 2012) of patients with HLHS undergoing TV repair and completing Fontan circulation. We evaluated the pre- and postoperative echocardiograms, intraoperative findings, and surgical techniques used. Results: A total of 53 TV repairs were performed in 35 patients with HLHS completing staged palliation. TV repairs were performed at stage II in 15, between stage II and III in 4, at stage III in 27, and after stage III in 7. The surgical techniques for valvuloplasty included annuloplasty (38%), anteroseptal (AS) commissuroplasty (66%), anterior papillary muscle repositioning (11%), multiple commissuroplasties (9%), septal-posterior commissuroplasty (9%), and fenestration closure (4%). The predominant jet of TR emanated along the AS commissure in 68% of the cases. All patients survived the procedure and were discharged. Preoperative echocardiography showed a dilated TV annulus on the lateral dimension, anteroposterior dimension, and area that was significantly reduced after TV repair (P < .0001). The preoperative mean TR, as assessed by lateral (P = .002) and anteroposterior (P = .005) vena contracta, was also significantly reduced after TV repair. TV repair did not significantly affect right ventricular systolic function immediately after surgery (P = .17) or at the most recent follow-up visit (P = .52). Patients with anterior leaflet prolapse were at increased risk of worse outcomes, including moderate or greater right ventricular dysfunction (P = .02). Patients requiring reoperation for TV repair were younger (6.3 vs 28.1 months, P < .0001) at the initial operation. One patient died of heart failure. Freedom from TV replacement and transplant-free survival were both 97% at the most recent follow-up point. Conclusions: TR in patients with HLHS commonly emanates from the AS commissure. The associated mechanisms are often annular dilatation and anterior leaflet prolapse. Preoperative anterior leaflet prolapse was associated with worse outcomes. Annuloplasty, closure of the AS commissure, and repositioning of the anterior papillary muscle are effective in addressing TR in the short-and mid-term in this challenging population.