Durability and elongation of artificial chords in pediatric mitral valve repair: A comprehensive echocardiographic analysis.

Abstract

To evaluate the long-term remodeling, biological adaptation, and clinical outcomes of expanded polytetrafluoroethylene (ePTFE) artificial chords (AC) used for pediatric mitral valve (MV) repair through comprehensive echocardiographic analysis. We retrospectively reviewed all patients younger than age 18 years undergoing MV repair with ePTFE AC between 2005 and 2024. Serial echocardiographic measurements included AC length, MV coaptation geometry, regurgitation severity and stenosis, and left ventricular (LV) volumes. Forty-two patients (median operative age, 5 years; interquartile range [IQR], 2-12 years) underwent MV with AC. Median follow-up was 4.0 years (95% CI, 2.5-7.0 years). Median AC number was 4 (IQR, 2-6). Progressive AC elongation was observed over time, with median diastolic AC length from 1.78 cm (IQR, 1.38-2.07 cm) at discharge to 2.28 cm (IQR, 1.88-2.70 cm) at 10 years, and median systolic length from 1.40 cm (IQR, 1.10-1.58 cm) to 2.10 cm (IQR, 1.60-2.50 cm). AC elongation correlated with LV volumes (end-diastolic and end-systolic, P = .002 and P = .018, respectively), suggesting coupling with ventricular growth. Transmitral gradients remained stable and no association between AC length and reduced coaptation length or increased tenting height were observed, supporting absence of leaflet restriction. No AC rupture or calcification occurred. At 10 years, cumulative incidence of moderate or greater MR was 45.5% (95% CI, 30.5%-68.0%), reoperation was 20.1% (95% CI, 10.8%-37.4%), and reprolapse with moderate or greater MR was 12.1% (95% CI, 5.3%-27.6%). In pediatric MV repair, ePTFE-AC demonstrated excellent durability and adaptative elongation alongside LV remodeling, without inducing valve restriction. These findings support long-term safety of AC-based repair and highlight ventricular-valvular remodeling in growing hearts.