脳灌流障害を伴うStanford A型急性大動脈解離に対する治療戦略

Antegrade Cerebral Perfusion in Stanford Type A Acute Aortic Dissection with Cerebral Malperfusion

Stanford A型急性大動脈解離（Stanford type A acute aortic dissection：AAAD）は，大動脈疾患の中でももっとも重篤かつ緊急性の高い病態である．発症後早期に外科的修復を行わなければ致死的転帰をたどることが多く，緊急手術の適応となる．2025年に発表された最新の「日本胸部外科学会年次報告2023」によると，7,120例のStanford A型急性大動脈解離の入院死亡率は10％であった1）．外科手術成績は手術手技や補助手段の進歩（特に脳保護）により改善してきたものの，脳灌流障害を合併する症例は依然として予後不良であることが知られており，脳灌流障害合併例では死亡率が15〜30％に達するとされる2～5）．さらに生存例においても重度の神経後遺症を残すことがあり，治療戦略上きわめて重要な課題である6～8）．

Stanford type A acute aortic dissection （AAAD） is a life-threatening cardiovascular emergency. Early surgical repair is essential to prevent fatal outcomes. According to the 2023 Annual Report of the Japanese Association for Thoracic Surgery, AAAD cases increased by 4.4％ in 2022, with an in-hospital mortality of 10％ for AAAD. Although surgical outcomes have improved with advances in cerebral protection techniques, patients with cerebral malperfusion remain at high risk of poor neurological outcomes and mortality, with postoperative death rates reported between 15～30％. Antegrade selective cerebral perfusion （ASCP） is the standard method for cerebral protection during circulatory arrest. However, in AAAD patients with carotid artery occlusion or severe stenosis, conventional ASCP may result in uneven cerebral perfusion, risking ischemia in the affected hemisphere. To address this, we introduced a two-roller pump technique, in which each carotid artery （affected and non-affected） is perfused independently using separate ASCP circuits. Cerebral perfusion was monitored with transcranial Doppler and regional cerebral oxygen saturation （rSO2）. The common carotid artery （CCA） was exposed via median sternotomy without additional neck incision, and direct cannulation was performed to establish targeted perfusion. The two-roller pump technique allowed independent regulation of flow and pressure for each carotid artery. Intraoperative monitoring confirmed stable perfusion to all cerebral vessels, including the previously occluded CCA. The two-pump technique prevented uneven blood distribution, reduced cerebral ischemia time, and was associated with improved immediate neurological outcomes. It enables immediate, controlled reperfusion of the affected hemisphere, potentially improving neurological outcomes, and offers a practical option for urgent surgical management of severe cerebral malperfusion in AAAD.