日本小児循環器学会雑誌 Pediatric Cardiology and Cardiac Surgery

In biventricular physiology, transcatheter right ventricular outflow tract (RVOT) stenting is indicated as an initial palliative alternative to a modified Blalock-Taussig shunt or to delay surgery for obstructed RVOT conduit. RVOT conduits may eventually need replacing because of luminal narrowing, regurgitation, or size mismatch associated with somatic growth. During the 2000s, reports from North America described acutely improved hemodynamics and the ability to postpone surgical replacement for 2.1–3.9 years with endovascular stenting for conduit stenosis. However, common complications of stenting RVOT conduits are free pulmonary regurgitation and frequent stent fracture. In addition, the potential risk of proximal coronary artery compression also limits its use when the anatomy is unfavorable. Recently, transcatheter pulmonary valve implants (TPVI), intended for treating RVOT conduit dysfunction, have become available in Europe and the US. However, size considerations may limit their use to smaller sized RVOT conduits. These uncertainties mean that stenting and surgery will remain necessary therapeutic options for conduit pathology, particularly in Japan where TPVI is unavailable. Given the likelihood of its continued use, we reviewed current trends in stenting for RVOT conduits in Japan and their potential risks and benefits.