Preparation: We recommend performing this procedure in a hybrid operation room. Bilateral cerebral oxygen saturation and invasive artery pressure in the bilateral upper limbs were monitored continuously during the operation.
Operation steps (Additional file 1: Video 1)
After performing sternotomy and opening the pericardium, the tissues were dissected free as much as possible to expose the aortic arch and supra-arch branches. The adventitia was reserved as much as possible to facilitate suturing of the fragile arteries in an acute setting. The patient was subsequently heparinised.
We used a fine paediatric vascular clamp, such as a Pilling clamp 354,486, to fully close the left carotid artery (LCA) and thus avoid secondary injury to the intima. We usually sutured the intima to the adventitia, which had been severely torn, using a 7–0 prolene suture and mattress-suturing and added a pericardial strip outside the carotid artery. Next, we completed the end-to-side anastomosis between the branch and LCA using a 6–0 prolene suture.
We then measured the length of the second branch of the aortic graft (28 mm; Interguard, Maquet, France) and clipped it, and clamped and transected the innominate artery and trimmed the end to prepare for anastomosis. We anastomosed the graft branch and innominate artery in an end-to-end manner using a 5–0 prolene suture, and completed the end-to-side anastomosis between the branch and left common carotid artery. These end-to-side and end-to-end anastomoses are key to understanding how to actively perfuse the brain. Specifically, this method does not cause brain circulatory arrest of blood flow from the carotid to the innominate artery during the procedure, yet it allows the aorta to be clamped near the carotid artery. The proximal end of the innominate artery does not require suturing if the segment has been severely dissected; rather, clamping can be performed until the aorta is closed.
The left femoral artery was exposed and cannulated using a cannula connected to the cardiopulmonary bypass to yield retrograde artery perfusion. A hybrid operating room can confirm that the cannula has been placed in the true aortic lumen. We inserted a two-stage cannula in the right atrium, and established another artery cannula branched from the artery end of cardiopulmonary bypass using a Y-shaped connector to the perfusion branch of the graft. Accordingly, the aorta was perfused in both an antegrade and retrograde manner, which allowed adequate perfusion of the viscera, even in the presence of preoperative malperfusion syndrome. The cardiopulmonary bypass was established, and the blood was cooled to 28 °C.
Once the blood temperature reached 32 °C, the aorta was clamped near the left common carotid artery. The ascending aorta was opened, and cardioplegia fluid was perfused into the left and right coronary arteries to induce cardiac arrest. We trimmed the proximal end of the aorta and reinforced the aortic wall with two Dacron strip patches using the sandwich technique. The distal end of the aorta was treated in the same manner. The distal anastomosis of the aorta and graft was achieved with a 3–0 prolene suture, after which we released the clamp distal to the graft to determine whether any bleeding would occur. We found that it was safer and more efficient to wrap the anastomosis with a strip patch than to use sutures. The proximal anastomosis of the aorta with the graft was performed in the same manner.
Finally, the patient was rewarmed and the heart beat recovered. The root of the left common carotid artery was closed using a 5–0 prolene suture to prevent retrograde blood flow into the false lumen. From that point, the aortic dissection was changed from type A to type B. Extracorporeal circulation was restored in a stepwise manner to complete the procedure. Angiography revealed the remaining distal dissection. Endovascular repair was not immediately required except in cases of low perfusion syndrome or a threatened rupture.
Two weeks later, the patient returned to the operating room, where a femoral approach to expose the femoral artery was performed under local infiltration anaesthesia. Once the catheter reached the ascending aorta, a superstiff guidewire (Lunderquist, COOK, US) was introduced for stent graft deployment. Finally, a 20-cm-long stent graft (34 × 200 mm; Tag, GORE, US) was deployed near the second graft branch orifice.