Abstract 12797: Morphology and Type of Repair of the Atrioventricular Valve in Patients With Single Ventricle Undergoing Staged Palliation

Abstract

Introduction: Significant atrioventricular valve (AVV) regurgitation is a known predictor of adverse outcomes after the Fontan procedure. AVV morphology in single ventricle can be complex and the underlying mechanisms of AVV regurgitation are multifactorial. Hypothesis: We analyzed our experience with AVV repair in patients with single ventricle, focusing on the mechanisms of AVV regurgitation and repeat AVV surgery. Methods: Among 460 patients undergoing total cavopulmonary connection (TCPC), 81 (18%) had at least one AVV repair prior or at TCPC. Morphology and function of AVV, ventricular type, and prior palliative surgery were analyzed in all patients in order to identify the risk factors for AVV repair, redo AVV surgery, and AVV replacement. Results: AVV morphology was two separated AVV in 24 patients (30%), mitral in 5 (6%), tricuspid in 36 (44%), and common AVV in 16 (20%). The initial AVV repair was performed at a median age of 2.0 [0.9-4.0] years. AVV regurgitation was due to one or more of the following mechanism: dysplastic leaflet in 45 patients (56%), leaflet prolapse in 42 (52%), cleft in 19 (24%), and chordal anomaly in 11 (14%). These structural anomalies were observed in 69 patients (85%), and two or more anomalies were involved in 49 patients (61%). Pure annular dilation was observed in 12 patients (15%). A second surgery was necessary in 30 patients (37%) and a third in 5 (6%). The initial repair was needed earlier in patients with a leaflet prolapse (p=0.01). Repeat repair was frequently needed in patients with high degree of AVV regurgitation prior to initial surgery (p=0.02) and common AVV (p=0.002). AVV replacement was frequently needed in patients with chordal anomalies (p=0.002) and two or more anomalies (p=0.001). Conclusions: In the majority of the patients, structural anomalies of the AVV lead to regurgitation, and cause early need of initial repair, of repeat surgery, and of AVV replacement. High degree of AVV regurgitation prior to initial AVV repair was a risk factor for repeat surgery.