“Collared Anastomosis” Technique Used in Arch Replacement Combined with Frozen Elephant Trunk Implantation Procedure for Giant Arch and Thoracic Aorta Dilatation

Correspondence To the Editor: We report two cases of arch replacement combined with frozen elephant trunk implantation procedure using the collared anastomosis technique for giant arch and thoracic aorta dilatation. A 62‑year‑old hypertensive female patient was admitted because of endoleak after thoracic endovascular aortic repair (TEVAR). The patient underwent TEVAR procedure because of Stanford type B aortic dissection 5 years ago. The proximal diameter of the stent graft was 50 mm. Another patient was a 52‑year‑old man suffering from arch and thoracic aneurysm. The diameter of the aneurysm was 52 mm. The ascending aorta and aortic valve of the two patients were normal. Aortic arch replacement and frozen elephant trunk implantation were performed. We developed the one‑stage open procedure for arch pathology and obtained satisfactory results. However, the diameters of the thoracic aorta were larger than the diameter of the frozen elephant trunk, resulting in difficulty in suture placement. As such, frozen elephant trunk procedure with a four‑branched hybrid graft is suitable for such implantation case. However, the four‑branched hybrid graft is still unavailable in China. As such, we made one using a four‑branched graft, a hollow graft patch, and a frozen elephant trunk during cooling. The steps were as follows: (1) Deploying the frozen elephant trunk out of the body; (2) anastomosing the graft and the frozen elephant trunk together (hybrid graft); (3) trimming a hollow graft patch; (4) suturing the graft patch at the joint of the hybrid graft; and (5) binding the frozen elephant trunk as previously mentioned [Figure 1a]. The endoleak can result in the persistent expansion of the aorta and is reported to be an important factor of aortic rupture. Sac enlargement was reported as the key cause of endoleak. For the first case, the stent graft implanted 5 years ago had a diameter of 50 mm and adhered to the aortic wall rigidly. As such, we left it in the aorta instead of pulling it out. The proximal naked part of the stent graft was trimmed, and then the frozen elephant trunk was deployed inside the previous stent graft. Then, the collar of the hybrid graft, the wall of the proximal aneurysm, and the proximal part of the previously implanted stent graft were anastomosed together as a " sandwich " [Figure 1b]. For the second case, the frozen elephant trunk of the hybrid graft was deployed inside the thoracic aorta, and then the collar …