新しい大動脈弁テンプレートを用いた自己心膜弁形成術

The Result of Aortic Valve Plasty with Autologous Pericardium Using Sawazaki’s Template

自己心膜を用いた大動脈弁再建術はOzakiら1）によって考案され，症例数は1,000例を超え，経過観察も17年に達し，再手術も少なく，長期耐久性は生体弁を凌駕している2）．しかし，作成した弁膜の弁高は高く，将来，経カテーテル的大動脈弁置換術（transcatheter aortic valve implantation：TAVI）を必要としたときに，大きな弁膜が冠状動脈口を閉塞してしまう．また，術後の心エコーで観察すると，接合した後の自由縁に5 mm程度の余剰な弁膜がflutteringしているのが観察される．これは，感染性心内膜炎の合併が多い要因ではないであろうか．そこでわれわれは，弁高の低いテンプレートを考案したので報告する．

The autologous pericardial aortic valve repair technique developed by Ozaki et al., using glutaraldehyde-treated autologous pericardium, has demonstrated superior durability to bioprosthetic valves. However, this technique has certain limitations, including excessive cusp height and cusp fluttering due to leaflet redunduncy. These limitations can lead to coronary ostium obstruction during transcatheter aortic valve implantation （TAVI） and postoperative infectious endocarditis. Consequently, we used a modified aortic valve repair technique using a Sawazaki’s cusp template with a reduced cusp height, approximately 8 mm lower than the original template. This modified template was used in 119 patients between 2012 and 2023, with a maximum follow-up of 11 years. The mean patient age was 74±6.5 years, with 41％ being male. The operative mortality rate was 0.8％, with one death attributed to injury of the left main trunk during selective coronary cannulation. Recurrent aortic regurgitation was observed in 4 patients, primarily due to commissural detachment （2 patients） and bottom cusp dehiscence （1 patient）. Therefore, the cusp template was enlarged by 1 mm, the bite size was increased, and small 2×2 mm square wings were added at both site of commissures to reinforce the structures. Three patients underwent aortic valve replacement, whereas 1 underwent TAVI. Notably, no cases of infective endocarditis were observed. The mean postoperative pressure gradient was 16.2±7.9 mmHg and the 11-year reoperation-free survival rate was 95.8％. In conclusion, the autologous pericardial aortic valve repair technique using the Sawazaki’s porcine cusp template resulted in excellent and favorable long-term outcomes.