Melody valve in mitral position: Complete fracture causing acute mitral stenosis in a child

Abstract

We present a case of a 7-year-old boy with a history of multiple mitral valve interventions and subsequent Melody valve placement in the mitral position, who presented with acute mitral stenosis due to complete fracture of the Melody stent. He was born early with severe mitral and tricuspid insufficiency due to valvular dysplasia, and ended up with 4 sternotomies before the age of 2 due to mitral valve dysfunction and recurrent prosthetic valve thrombosis. He then developed mixed stenosis and regurgitation at age 6, and to avoid another sternotomy, valve-in-valve therapy with off-label use of a 20-mm Melody valve was done with hybrid procedure via trans-apical approach. Eight months later he presented with acutely worsened mitral stenosis (mean gradient 20 mm Hg), due to fracture of the proximal stent. While the safety and efficacy of the Melody valve has been well established especially in the pulmonary position, stent fracture is a known and potentially serious complication. As with any novel valve therapy, close follow-up and frequent imaging may be warranted to watch for loss of stent integrity, particularly if clinical symptoms of valve dysfunction occur.

Transcatheter Heart Valves: A Biomaterials Perspective

“…Although stent failure is not as prominent as leaflets, reports show stent fracture and failure have led to stenosis and higher‐pressure gradient. [ 149 ] Stent design is important when considering valve migration, anchoring, and structural valve deterioration. Thrombosis, thromboembolism, and hemolysis due to stent/strut fracture have also been reported.…”

“…[ 211 ] Unfortunately, common complications include those often found with off‐label use for pediatrics, such as valve dislodgement, stent fracturing, recurrent stenosis, and regurgitation. [ 149,156,157b ] These problems may be rectified by redesigning the current commercial transcatheter valves and tailoring them toward the needs of the younger population. The recent development of expandable prosthetic valves to allow somatic growth for pediatric patients may spark interest in the transcatheter deployment of these novel pediatric valves, whose designs are strikingly similar to THVs.…”