Morbidity and mortality can be improved by reducing blood perfusion; the durations of general anaesthesia, cardiopulmonary bypass, and abnormal hemodynamics; and carefully protecting the myocardium and brain. Since 2012, 41 patients (aortic dissection, 36 cases; arch aneurysm, 5) have undergone a procedure that was gradually modified, including the brain perfusion manner, branch priority, retrograde stent graft deployment via the femoral approach, a two-stage concept involving two-branch anastomosis. Arch replacement surgery could be completed within approximately 4 h, and during 2 years of treating aortic dissection or arch aneurysm, only four anastomoses were required during the first stage of surgery: two in the aorta and one each in the innominate and left common carotid arteries. No patient died of surgical causes, and no stent grafts deployed into the false lumen, which tends to occur with traditionally antegrade deployment.
The left subclavian artery remained perfused by the aorta from the true or false lumen after graft replacement after the first stage. It could be covered by the stent graft or reserved for the second stage. We were also able to reconstruct blood flow in all three supra-arch branches. For example, if a patient had an advantage of the left vertebral artery, we might consider an end-to-end anastomosis between the left subclavian artery and third graft branch during the rewarming period. The left carotid artery could be transected at the root and pushed aside to facilitate dissection of the subclavian artery (see Fig. 1).
Perfusion via the graft helps to avoid the deployment of other types of perfusion, e.g. auxiliary artery retrograde perfusion and antegrade cerebral perfusion via a catheter. Anastomosis of the supra-arch branches is performed before initiating CPB, and can thus be performed easily to ensure quality. The body temperature is lowered only to 28–32 °C during cardiac arrest, thus reducing the rewarming period. Altogether, these modifications save approximately 3 h.
If the left common carotid artery is occluded by a torn intima, the first anastomosis can be performed between the left subclavian artery and graft branch [3].
The very stiff guidewire and stent profile, which are curved prior to surgery, help to deliver the stent graft into the distal aortic graft.
For type A dissection, in order to shorten surgery time as possible, we recommend that our procedure be performed in two stages, especially for patients with the most severe conditions (e.g., hypotension with heart/brain/liver/kidney injury; older age; obese; cerebral infarction). However, one-stage treatment is required if intraoperative angiography (contract agent injected through the graft branch) confirms malperfusion of the viscera or lower extremities. The retrograde manner of stent deployment avoids plunging the stent graft into the false lumen through the torn intima (compare Figs. 2 and 3).
An arch aneurysm can be treated in a single stage, as false lumen deployment is not a concern. This is very similar to hemi-arch replacement with a stented graft/elephant trunk into the proximal descending aorta. In the former, we have more choosable specifications and models of the interventional stent grafts than the graft of the latter in China. That is important for protecting the descending aorta containing stent graft. The best stent graft we think is as soft as it can be to fit the diameter and shape of descending aorta. Further more, although aneurysm surgery is easier than dissection, we still suggest avoiding cardiac arrest if possible, unless the femoral approach of stent graft delivery is not permitted.
Although simplified, this procedure remains a major surgery for patients experiencing great distress, malperfusion, and abnormal hemodynamics resulting from an aortic dissection type A. If a sufficient segment of normal ascending aorta remains, a TEVAR procedure, which reserves the supra-arch branches, or a debranch procedure is recommended for simplicity and safety [4]. There remains room for potential improvements to further simplify this technique in the future.