Stanford A型急性大動脈解離手術において大動脈基部に対する介入は必要か

Should Aortic Root Intervention Be Performed in All Cases of Stanford Type A Acute Aortic Dissection?

Stanford A型急性大動脈解離（Stanford type A acute aortic dissection：AAAD）は緊急手術を要する致死的疾患であるが，近年の手術成績の向上により救命率は著しく改善している．一方で大動脈基部にまで解離が及んでいる症例においては，Bentall手術や自己弁温存基部置換術（valve-sparing root replacement：VSRR）といった基部再建術が必要となるか否かの判断が依然としてむずかしく，術式選択の指針はいまだ定まっていない．

Objective：To evaluate the outcomes of aortic root preservation in patients undergoing surgery for Stanford type A acute aortic dissection （AAAD） without concomitant root replacement.

Methods：We retrospectively analyzed 79 consecutive AAAD patients （mean age 68±13 years；52％ male） who underwent supra-coronary repair （SCR） between January 2012 and December 2022, excluding those requiring Bentall or valve-sparing root replacement （VSRR）. Preoperative root involvement, aortic regurgitation （AR）, surgical procedures, early outcomes, long-term aortic root dilation, AR progression, and reoperation rates were assessed mean follow-up of 5.7±3.4 years.

Results：Preoperative root dissection was present in 66％, with moderate or greater AR in 16％. Early mortality was low （30-day mortality 2.5％, in-hospital mortality 3.8％）. Long-term follow-up, mean aortic root enlargement was minimal （0.28 mm/year）, with no cases of progression to moderate or severe AR. Reoperation occurred in 3.8％ （3 cases）, primarily due to pseudoaneurysm or new entry formation at the proximal anastomosis.

Conclusions：Aortic root preservation with careful proximal anastomosis placement provided excellent early and mid-term outcomes, with minimal late aortic root dilation or AR progression.