Medium term follow-up after percutaneous pulmonary valve replacement with the Melody® valve

Abstract

IntroductionData on long term function of the Melody valve are scarce.Patients and methods: single institution; results of percutaneous pulmonary valve implantation (PPVI) from 2006 to 2014. The function of the valved conduit was analyzed by Doppler echocardiography. Annual Chest X-ray after implant and permanent screening for events (e.g. Endocarditis).Results112 Melody valves were implanted in 111 patients; mean age 19.3 years (4.5–81.6). No pre-stenting of the RVOT was performed (n = 4) at first. In the next 107 patients pre-stenting was always performed. In 82 patients 1 pre-stent, 18 patients 2, in 6 patients 3 stents and 1 patient 4 stents were used. The Melody stent was dilated up to 24 mm (n = 4), 22 mm (n = 72), 20 mm (n = 28) and 18 mm (n = 6). When stenotic, the Doppler gradient reduced from 67.0 mm Hg (SD 13.9) to 18.9 mm Hg (SD 10.4) (p < 0.001); pulmonary regurgitation (PR) was reduced from median 3.5/4 (range 0–4/4) to none or trivial (p < 0.001). There was no significant change in RVOT peak velocity at 5 years (p = 0.122) nor PR (p = 0.835). Type 1 stent fractures were observed in 1/4 non-pre-stented patients and in 5/107 pre-stented (p < 0.05).Endocarditis occurred in 8/112 valves; freedom of endocarditis was 85% at 5 years. In 2 patients early surgical replacement was necessary. Six were sterilized with antibiotic treatment; 2 patients required re-stenting and re-PPVI due to residual gradient.ConclusionAdequate pre-stenting of the RVOT before PPVI nearly abolishes or delays stent fracture. Cusp function is well preserved in mid-term follow-up; endocarditis is a threat.

Transcatheter Pulmonary Valve Implantation: A Comprehensive Systematic Review and Meta‐Analyses of Observational Studies

“…The procedural success for TPVI is greater than 96%, with a complication rate of 10%. Our pooled estimate for procedural success is consistent with the high rates reported in the US IDE trial and postapproval study as well as the larger European studies . Failed TPVI procedures were commonly associated with a complication requiring surgical conversion, which occurred in over 3% of cases.…”

“…In comparison, the postapproval study by Armstrong et al observed prestenting in 76 of 101 patients . Similarly, Cools et al and Fraisse et al report prestenting rates of 96.4% and 96.9%, respectively . Schievano et al, in their in vitro modeling study, showed that a stent‐in‐stent technique decreased mechanical stress on the TPV stent struts .…”

“…Nineteen observational studies met inclusion criteria and were included in the final analysis. Table illustrates the baseline characteristics of the included studies.…”

“…Breaking these down, catheter‐based reinterventions accounted for 2.7 events per 100 PY (95% CI, 1.7–3.7) whereas adjusted rate for surgical reinterventions was 1.7 per 100 PY (95% CI, 1.2–2.2). There is significant heterogeneity in the studies in this regard, which is negated once we analyze studies after adoption of prestenting (Figure ) . In total, 77.5% of reinterventions were done for restenosis, 15.2% for endocarditis, only 1.8% for valve insufficiency, and 5.2% for other indications.…”

Right ventricle outflow tract prestenting: In vitro testing of rigidity and corrosion properties

“…Stent fractures following PPVI give rise to varying degrees of hemodynamic impairment ranging from mild to severe with or without valve dysfunction . Recent midterm follow‐up of the Melody valve identified elements associated with a higher risk of stent fracture . Geometrical anomalies of the stented valve such as deformation and compression increase the risks while implantation within a protected RVOT was proven to lower risks .…”