高度組織破壊を伴った大動脈弁位活動期感染性心内膜炎に対するステントレス生体弁を用いた弁置換術

Surgical Treatment of Extensive Annular Defects by Aortic Valve Infective Endocarditis Using Stentless Bioprosthesis

活動期感染性心内膜炎（IE）における大動脈弁の感染が周辺組織に高度に進展した場合，通常の大動脈弁置換術（AVR）では対処困難なことが多く，ホモグラフトやcomposite graftを使用した大動脈基部置換術などの拡大手術を余儀なくされる1）．大動脈弁輪部の感染は弁輪の破壊，膿瘍形成を経てintervalvular fibrous body（IFB）へ波及し，僧帽弁まで進展する．また仮性瘤の形成，膜性心室中隔への感染波及による房室ブロックや隣接するほかの心腔内へのシャントをきたす．特に人工弁IE（PVE）では，人工弁摘出と感染組織の郭清によって広範囲に左室と大動脈弁輪の連続性が消失するleft ventricular-aortic discontinuity2）を呈することがあり，さらに複雑化した手術を必要とする．

Background：The optimal surgical technique and valve prosthesis in patients with active aortic valve infective endocarditis with annular abscess is controversial. If extensive annular defects occur after debridement, standard techniques are difficult；more complex aortic root replacement is inevitable. The SOLO SMART stentless bioprosthesis is specially designed for supra-annular implantation without annular stitches.

Methods：Since 2016, 15 patients with active aortic valve infective endocarditis underwent aortic valve surgery. Of these, we performed aortic valve replacement using the SOLO SMART valve in six patients with extensive annular destruction and complex aortic root pathologies requiring reconstruction.

Results：Although more than two-thirds of the annular structure was missing after radical debridement of infected tissues, supra-annular aortic valve replacement with the SOLO SMART valve could be performed successfully in all six patients. All patients are doing well without prosthetic valve dysfunction and/or recurrent infection.

Conclusions：The supra-annular aortic valve replacement using the SOLO SMART valve is considered to be a useful alternative to standard aortic valve replacement in patients complicated with extensive annular defect. It is a simple and technically less demanding alternative to aortic root replacement.