The main pathologic feature of TA is the extensive destruction of the medial elastic fibers that maintain the strength of the aortic wall [4, 5]. This feature often leads to stenosis, occlusion, or aneurysmal degeneration of the aorta and its major branches [1]. Although the involvement of arch vessels has been detected more frequently in Japan [2, 3], there have been few articles about surgical repair for arch vessel aneurysms in TA.
Operative indications for BCA aneurysms include either ruptured or symptomatic aneurysms, such as distal embolization or compression of the adjacent structures. When the aneurysms are saccular or when their maximum transverse diameter is more than 3 cm, surgical repair should be considered, even when asymptomatic [7]. Although the present case did not present with any symptoms related to the aneurysm, a size of over 3 cm was the deciding factor for surgical treatment.
Treatment strategy for BCA aneurysm depends on the extent of involvement. When the lesion is extremely localized, endovascular repair can be performed, but this method is rarely enforceable. Mostly open surgical repair including graft interpose, patch plasty with partial clamp, and partial or total aortic arch repair has been reported [7]. Patch plasty with partial clamp seemed desirable because circulatory arrest would have been avoided; however, anastomotic problems remained. Okita et al. reported a higher incidence of pseudoaneurysm or residual aneurysmal formation after patch repair for a saccular aneurysm of the aortic arch [8].
Furthermore, in TA, it often happens that the aorta has been affected by chronic inflammation, even though the preoperative images appeared to show a healthy and normal aorta. Because a serious long-term complication in TA includes anastomotic aneurysms, sites of normal tissue without inflammatory changes should be chosen as the anastomotic sites [4]. It is also important to exclude inflamed cervical vascular lesions [3]. In accordance with these reports, reinforcement of the sutures has been recommended [1]. In the present case, reinforcement of the proximal and distal anastomosis with Teflon felt strips at inner and outer side of aortic wall was performed. Because an anastomotic aneurysm may occur at any time after surgery, regular follow-up using multiple imaging modalities is mandatory [5]. Although systemic inflammation or steroid administration had reportedly little influence on formation of anastomotic aneurysm [4, 5], suppression of active or persisting inflammation with corticosteroids is recommended [1, 3].
In aortic surgery for patients with severe atherosclerotic changes, protection of the brain tissue is important. There have been many reports describing various strategies for brain protection; however, the optimal management remains unclear. Axillary or BCA perfusion seems promising, but turbulent flow in the proximal aortic arch may still dislodge the atheroma [6]. Furthermore, bilateral axillary artery perfusion may fail to reduce the risk of embolism of the left common carotid artery because blood flow from the axillary arteries spreads into the aortic arch, resulting in plaque disruption by jet flow [9]. Shiiya et al. introduced an isolation technique to address these issues [6]. This technique involves the concept of distributing blood flow to each neck vessels individually, resulting in the prevention of a distal embolism. Kasama et al. reported the advantage of this method by investigating ICP in elderly patients with severely atherosclerotic changes [9]. In the present case, this strategy enabled us to avoid jet flow from the aortic arch, and the patient recovered without any neurological deficits. Slowly establishment of the cardiopulmonary bypass through a femoral artery and additional carotid artery perfusion could prevent plaque embolism from the aortic arch. Further studies on the effectiveness of ICP are warranted.