経皮的バルーン血管形成術は，狭窄血管を内腔より拡張し内膜から中膜にかけて一時的な亀裂・解離を生じさせ，より大きな内径へ血管リモデリングを促し血行再建することを目的とする治療である．術後遺残狭窄病変を対象に広く行われ圧較差・形態を主眼に対象病変を抽出する．狭窄病変は肥厚・萎縮・低形成・圧迫・硬化など多様性を包含し，基本的に経皮的バルーン血管形成術は肥厚病変に対して最も効果的であり，萎縮・圧迫・低形成病変に対してはバルーン治療の効果は期待できずステント治療・外科治療なども考慮される．血管形成用バルーンは高耐圧バルーンを基本とし，硬化病変に対して超高耐圧バルーンを選択する．狭窄部最小径と周辺の参照血管径から至適バルーン径を決定し，体格を加味してアクセスのためのシース・親カテーテル・ガイドワイヤーを決定してゆく．リスク評価として術後経過時間，人工物介在の有無，バルーン拡張時の周辺への干渉や血行動態に及ぼす影響を事前に評価した後，狭窄病変へのガイドワイヤーの導入，バルーンカテーテルのデリバリーと拡張，効果判定の各段階を経て実行される．適切で効果的なガイドワイヤーの留置が成功への鍵となり，治療システムが心内を通過する場合には治療中の血行動態変動に常に留意し治療システム全体の安定に努める．バルーンウエストの消失を治療完遂基準として数回の加圧を行い，バルーンカテーテル抜去後の血行動態測定と血管造影により最終的効果判定を行う．先天性心疾患における経皮的バルーン血管形成術は個々の多様な病変を対象とするため，その治療計画は個別に立案されるべきで経験の積み重ねが必要である．
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.
Key words: congenital heart disease; catheter intervention; pulmonary arterial stenosis; noninvasive therapy
© 2022 特定非営利活動法人日本小児循環器学会© 2022 Japanese Society of Pediatric Cardiology and Cardiac Surgery
This page was created on 2022-09-27T09:30:03.544+09:00
This page was last modified on 2022-11-08T14:52:14.000+09:00
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