Impact of percutaneous pulmonary valve implantation procedural steps on leaflets histology and mechanical behaviour: An in vitro study

Zakaria Jalal (1) , Louise Galmiche (2) , Christophe Beloin (3) , Younes Boudjemline (4, 1)

1 CARPEDEM-M3C - Centre de Référence M3C Malformations Cardiaques Congénitales Complexes [CHU Necker]
2 Laboratoire d'anatomie pathologique [CHU Necker]
3 Génétique des Biofilms
4 UPD5 - Université Paris Descartes - Paris 5

Background: Percutaneous pulmonary valve implantation (PPVI) using bovine jugular vein Melody valve is safe and effective. However, post-procedural complications have been reported for unclear reasons. Objective: We sought to assess the impact of PPVI procedural steps on valvular histology and leaflet mechanical behaviour. Methods: Three different valved stents (Melody valve, homemade stents with bovine and porcine pericardium) were tested in-vitro in 4 conditions: I) control group, II) crimping, III) crimping + inflation of low-pressure balloon and IV) condition III + post dilatation (highpressure balloon). For each condition, valvular leaflets (and venous wall sample for Melody stents) were taken for histological analysis and mechanical uniaxial tests of valve leaflets. Results: Among Melody valves, incidence of transverse fractures was significantly higher in traumatized samples compared with control group (p<0.05) whereas, incidence and depth of transverse fractures were not statistically different between the 4 conditions for bovine and porcine pericardial leaflets. No significant modification in mechanical behaviour of in-vitro traumatized Melody® valvular leaflets was observed. Bovine and porcine pericardia became more elastic and less resilient after balloon expansion and post-dilatation (condition III and IV), with a significant decrease of elastic modulus and stress at rupture. Conclusion: Valved stent implantation procedural steps induce histological lesions on Melody valve leaflets. Conversely, bovine and porcine pericardial valved stents were not histologically altered by in vitro manipulations although their mechanical properties were significantly modified. These data could explain some of the long-term complications observed with these substitutes.

Mots clés: percutaneous valve; pulmonary valve; endocarditis

Domaines: Cardiologie et système cardiovasculaire

Zakaria Jalal, Louise Galmiche, Christophe Beloin, Younes Boudjemline. Impact of percutaneous pulmonary valve implantation procedural steps on leaflets histology and mechanical behaviour: An in vitro study. Archives of cardiovascular diseases, 2016, 109 (8-9), pp.465 - 475. ⟨10.1016/j.acvd.2016.01.015⟩. ⟨pasteur-01377070⟩