Basis of Transcatheter Balloon Angioplasty for Pulmonary Stenosis

<p>Transcatheter balloon angioplasty aims to promote vascular remodeling through temporary dissection in the vascular wall and approach the larger diameter of the targeted vessel. Transcatheter balloon angioplasty is indicated for postoperative vascular stenosis associated with congenital heart diseases, and the identification of the stenotic lesion depends upon the pressure gradient and anatomy. Stenotic lesions involved thickened, atrophic, hypoplastic, compressed, and stiff lesions, and balloon angioplasty is the most effective for thickened lesions. Stent implantation or surgical repair rather than balloon angioplasty is expected to be effective in other types of stenotic lesions. High-pressure balloons are basically used for balloon angioplasty, and ultrahigh-pressure balloons may be chosen to treat the stiff stenotic lesions. The optimal balloon diameter is determined according to the narrowest and adjusted vessel diameters. Then, the sizes of the sheath, guiding catheter, and guide wire are determined according to the balloon catheter and body size. The risks for transcatheter balloon angioplasty are stratified according to the duration after the last surgical intervention, presence of artificial material, interference to the surrounding tissue, and influence on hemodynamic alteration during the procedure. Additional procedures are performed stepwise, including the introduction of the guidewire, delivery of a balloon catheter, inflation of the balloon at the stenotic lesion, and assessments of hemodynamic and anatomical results. Placing a guidewire at the appropriate position is important for a successful procedure. When the procedure is performed through right heart structures, maintaining stable hemodynamics during the procedure is critical. The disappearance of the balloon waist is the criterion for the completion of treatment. Hemodynamic and anatomical alterations across the target lesion are assessed after the withdrawal of the balloon catheter. As transcatheter balloon angioplasty for congenital heart disease targets various lesions, individual planning and experience for procedures are necessary.</p>