Sun’s procedure is currently recognized as the standard procedure for AAAD. The incidence of residual distal false lumen patency from Sun’s procedure is less than 5%, and the reoperation rate is less than 10% [10,11,12].
DHCA is indispensable for Sun’s procedure. But DHCA may cause abdominal organ dysfunction such as ischemia-reperfusion injury, coagulation dysfunction, nervous system dysfunction and kidney dysfunction. Besides, the incidence of these dysfunction is positively correlated with the duration of DHCA [13,14,15,16].
Hybrid surgery can reduce the difficulty of the operation and recent complications by avoiding DHCA, but it also leads to a relatively high incidence of late complications [17, 18], due to its lack of one important step of Sun’s procedure that the expandable stent graft can be firmly fixed to the distal 4-branched prosthetic graft using the suture line. One study reported that the incidence of late complications was up to 48%, including delayed type I endoleak, stent migration, stent fracture and so on. Furthermore, 10% of the patients underwent late open surgery [19, 20].
In order to solve these problems, we coined a new surgery which is a combination of Sun’s procedure and hybrid surgery. In this surgery, we proposed that we could use 1 min of circulatory arrest to place the expandable stent graft into the aorta. This amount of time is so short that there is no need for deep hypothermia.
The time that DHCA is safe is 30–40 min; the shorter the time is, the better [21, 22]. If surgeons can not complete high-quality complex surgery as soon as possible during safe operational time window, patients may be left with serious complications. So they need relatively advanced skill, much experience and excellent psychological quality.
On the contrary, a surgeon does not need to worry about the time of circulatory arrest in our surgery. Thus, it apparently reduces the psychological pressure on the surgeon, which is conducive to a better effect.
When the distal aortic arch is anastomosed, bilateral anterograde cerebral perfusion and retrograde femoral artery perfusion are adopted. There is theoretical possibility of retrograde tear of the dissection pseudolumen during retrograde femoral artery perfusion. However, some research shows that this approach is safe and reliable .
In Sun’s procedure, it is difficult to handle the root of the left subclavian artery, and the recurrent laryngeal nerve can be easily injured. End-to-side anastomosis was performed between the graft and left subclavian artery via a left infraclavicular incision in our surgical procedure. During the operation, the left vertebral artery could be perfused continuously through the graft, which is helpful for protecting the brain and spinal cord. The distal anastomosis was located between the innominate artery and the left carotid artery, which was relatively simple and easy to be exposed. Then, sutures were placed, and the hemostasis was maintained. The risk of bleeding and recurrent laryngeal nerve injury was reduced. Since the three branches of the aortic arch were perfused continuously, they were anastomosed after the reconstruction of the aortic arch so that the length and location of the branches were easier to be adjusted, which further reduced the difficulty of the operation.
In the study, one patient experienced aggravation of renal damage from preoperative renal insufficiency to postoperative renal failure After treatment with continuous renal replacement therapy (CRRT), his renal function returned to be normal. No paraplegia, liver failure or other abdominal organ ischemia complications occurred in this study. The adoption of continuous perfusion of the subclavian artery and less than 1 min circulatory arrest reduced the risk of ischemia and ischemia reperfusion injury. Therefore, this approach is beneficial for the protection of the spinal cord and abdominal organs and allows for the possibility of reducing the incidence of related complications.
In addition, another advantage of our operation is that the location of anastomosis on the aorta is altered from the left subclavian artery to the innominate artery, which decreases the risk of bleeding and complexity by shifting anastomosis more proximally.
It is also one of the aprroaches to prevent DHCA that coda balloon or Foley’s catheter is used to block descending thoracic aorta and then lower body can be perfused by femoral artery, which can also protect abdominal organs,which can also protect abdominal organs [24,25,26]. However, compared with our operation, there are some disadvantages, such as blood leakage around the balloon and unclear vision when the distal end is sutured. What’s more, the anastomosis is still too far for the surgeon, which cannot reduce the difficulty of operation.
The number of locations for anastomoses was more in this procedure than that in Sun’s procedure; thus, the overall operation time of this operation was appropriately longer than that of Sun’s procedure.