Endovascular stent graft placement has widely been confirmed as an effective aortic repair technique for acute aortic dissection, which can seal off the intimal tear and lead to quick clot formation and shrinkage of the false lumen [6, 9].
The Shimamura’s [10] branched open stent-grafting technique is an evolutionary hybrid aortic arch repair procedure that combines conventional aortic surgery and endovascular repair with branched endoprosthesis. The outstanding point is that the branched open stentgrafting technique provides total arch repair without performing direct surgical reconstruction of the descending thoracic aorta and cervical branches. The distal aortic incision line is almost the same as in the hemiarch repair, and the branched endoprosthesis completes arch repair within an acceptably short interval of DHCA. But Shimamura’s endoprosthesis is homemade, it is not convenient to use. Our technique was designed to repair the proximal descending aorta, arch, and 3 arch vessels simultaneously by the simple open placement of triple-branched stent graft into the descending aorta, arch, and 3 arch vessels instead of direct surgical repair. In this study, we successfully applied our open triple-branched stent graft placement technique combined with graft replacement of the ascending aorta in extensive primary repair of the thoracic aorta in 13 patients with acute arch dissection. Placement of these triple-branched stent grafts into the descending aorta, arch, and 3 arch vessels was finished in 5 to 20 minutes during the procedure. All patients had recovered uneventfully and were discharged from hospital without complications. Their postoperative computed tomographic scans showed that all stent grafts were opened and not kinked, there was no endoleak and no sidearm graft occlusion.
Open placement of the conventional straight stent graft into descending aorta in the hybrid technique of Kato [7–9] has been proven to be an effective way of closing the residual false lumen of the descending aorta. Our preliminary results and others [11] demonstrated that the open triple-branched stent graft placement is a feasible and effective technique for extensive primary repair of the thoracic aorta in acute arch dissection.
The purpose of our technique is to obtain extensive primary repair of the thoracic aorta for acute arch dissection with less invasiveness. Our technique offers a number of advantages over the four-branched arch graft technique:
First: less anastomosis, simplified the operation
In our technique, extensive primary repair of the thoracic aorta could be performed simply by both open placement of the triple branched stent graft into the proximal descending aorta, arch, and 3 arch vessels and graft replacement of the ascending aorta, which could reduce the risk and technical difficulties of extensive thoracic aorta repair to close to those of the conventional ascending graft replacement with open distal anastomosis. In the hybrid procedure of Kato [5], careful manipulation of the arch and elaborate anastomoses to the distal aortic arch and 3 arch vessels are time-consuming. Moreover performing anastomosis and hemostasis at the descending aorta is usually very difficult. Our open triple-branched stent graft placement technique can reduce such problems. Therefore, cardiopulmonary bypass time, aortic cross-clamp time, and selective cerebral perfusion and lower body arrest time were shorter than in the Kato and Sun’s hybrid technique seen in previous reports [5, 6] and were comparable to those of conventional ascending replacement with open distal aortic anastomosis.
Second: less bleeding
Open triple-branched stent graft placement technique makes it easy to control bleeding, we have observed less bleeding and did not encounter any difficult bleeding. No patient required additional surgery to correct excessive postprocedural bleeding. Three reasons explain this: first, anastomoses to 3 arch vessels were totally avoided; second, the distal aortic anastomosis at the distal ascending aorta, which provided a better surgical view for performing anastomosis and hemostasis; Finally, shorter time on cardiopulmonary bypass and deep hypothermic circulatory arrest contributed to the quick recovery of postoperative blood coagulability.
Finally: less damage to vital organs and quick recovery
With our open triple-branched stent graft placement, as the surgical procedure simplified, the three branches of the aortic arch and descending aorta anastomosis reduced, deep hypothermic circulatory arrest time of significantly shortened, reducing the deep hypothermic circulatory arrest for vital organs such as brain, lung and kidney to avoid postoperative stroke, acute renal failure and dialysis. Reduce the adverse impact on lung function, avoiding the occurrence of acute respiratory insufficiency, reducing respiratory infection. Therefore, all patients had a short time on postoperative mechanical ventilation and a short stay in the intensive care unit and shortened hospital stay in this group. Improvement of prognosis after surgical repair of acute type A dissection is largely dependent on the reduction of complications.
Postoperative CT showed that all sidearm stent grafts were fully opened and no sidearm stent graft endoleak. For these good results, diameters of the 3 sidearm grafts, distances between 2 neighboring sidearm grafts, and proper placement of the triple-branched stent grafts were crucial. For each patient, the diameters of the selected grafts should be 10% to 20% bigger than the diameters of the native aortic arch and arch vessels, respectively [5, 13]. The proper size of each graft was key for quick clot formation and shrinkage of the false lumen and for preventing new intimal trauma resulting from the continuous compression of the oversized stent graft on the dissected and frangible intimal wall [5, 7]. The distances between 2 neighboring sidearm grafts should be approximately equal to the distances between 2 corresponding arch vessels, which would keep sidearm stent grafts from being twisted or kinked after deployment. It is reported that some risks such as postoperative stent graft shifting or kinking may be occur [14]. But in this study, no sidearm graft occlusion was observed because we use 3-0 Prolene suture reinforced with Teflon band near the innominate artery, left subclavian artery and the main vessel stent through the suture arterial wall to prevent the late shift and poor adhesion. The long-term patency of those sidearm grafts should be carefully evaluated.