Debranching thoracic endovascular aortic repair combined with ascending aortic aortoplasty.

Surgical treatment of aortic arch lesions is a challenge for cardiac surgeons because of the complexity of the technique. For high-risk patients who are not suitable to undergo traditional open arch replacement, debranching thoracic endovascular aortic repair (d-TEVAR) is often a good choice. Retrograde type A aortic dissection (RTAD) is a common and fatal complication after d-TEVAR,[ and thus d-TEVAR is contraindicated in low-risk patients. Herein, we describe a modification of d-TEVAR with an aortoplasty of the ascending aorta using artificial blood vessels and the subsequent use as an anchoring zone to minimize the occurrence of RTAD.

This procedure is used in patients with lesions involving a part of or the entire aortic arch, but not involving the ascending aorta. Under general anesthesia, a median sternotomy was performed, and three arch vessels were mobilized. The aorta was clamped with a side wall clamp, and an incision of appropriate size was made. The main artery of the Y-shaped artificial blood vessel (Vascutek, 16 × 8 mm; Vascutek Terumo, Inc., Scotland, UK) was anastomosed to the sidewall of the ascending aorta. Next, the innominate artery was blocked and cut. The proximal end was sutured, and the distal end was anastomosed to the Y-shaped artificial blood vessel branch. After de-airing, the block was opened with forceps to restore the blood supply of the artery. The left common carotid artery was then blocked and cut. The proximal end was sutured and the distal end was anastomosed to the corresponding position of the other branch of the Y-shaped blood vessel in an end-to-side fashion. After de-airing, the block was opened with forceps to restore the blood supply of the artery. Then, the left subclavian artery was blocked and cut. The proximal end was sutured and the distal end was anastomosed with the distal end of another Y-shaped artificial blood vessel branch. After venting, the block was opened with forceps to restore the blood supply to the artery. No assistance with cardiopulmonary bypass was required during this process. A straight artificial blood vessel (InterGard; InterVascular S.A. MAQUET Cardiovascular, La Ciotat, France or Vascutek, Inchinnan, UK) was wrapped around the ascending aorta and both ends of the artificial vessel were marked with a titanium clip [Supplementary Video 1]. After aortic angiography [Supplementary Video 2], the proximal end of the stent-graft was positioned in the ascending aorta wrapped with the artificial vessel and the stent was then released to close the lesion [Figure 1]. The surgery was completed after a repeat angiography [Supplementary Video 3].

Figure 1

A schematic for the d-TEVAR procedure. (A) An aneurysm involving the aortic arch. The left subclavian artery originates from the aneurysm. (B) The debranching technique was used to reconstruct the aortic arch vessels. No assistance with CPB was required in this process. (C) A straight artificial vessel was wrapped around the ascending aorta. (D) The proximal end of the stent-graft was positioned in the ascending aorta wrapped with the artificial vessel, which was used as the anchoring zone. The straight artificial vessel enhanced the strength of the ascending aortic wall and reduced the compliance mismatch between the ascending aortic anchoring zone and the proximal end of the stent. CPB: Cardiopulmonary bypass; d-TEVAR: Debranching thoracic endovascular aortic repair.

The d-TEVAR provides a new option to treat aortic arch lesions, but the use of d-TEVAR is limited to high-risk patients due to the high incidence of serious complications, such as RTAD. RTAD occurs mainly for the following reasons: (1) side-clamping injury of the ascending aorta[; (2) damage to the arterial wall by catheter angiography and wire manipulation[; and (3) compliance mismatch between the still rigid stent-graft and the highly compliant ascending aorta.[ The first two reasons can be avoided by using meticulous techniques during surgery. Reason (3) can be avoided by using artificial vessels to wrap the ascending aorta. We know that the ascending aorta undergoes both radial expansion-contraction and wall translational motion with the beating of the heart and has high compliance,[ while the stent-graft is stiffer. These slight back-and-forth motions of the stiff endograft with the cardiac cycle increase the risk of RTAD. Some researchers believe that when the ascending aorta is <40 mm in diameter, the ascending aorta may be directly used as the anchoring area. When the ascending aorta is >40 mm in diameter, the ascending aorta should be replaced before TEVAR[; however, we believe that regardless of the diameter of the ascending aorta, it is unsafe to use the fragile and frequently moving ascending aorta as an anchoring zone. Only artificial blood vessels after ascending aortic replacement or the ascending aorta wrapped with artificial vessels can be used as an anchoring zone. Artificial vessel wrapping enhances the strength of the ascending aortic wall and limits the radial expansion-contraction movement with the cardiac cycle, thereby reducing compliance mismatch between the anchoring zone and the proximal end of the stent and thus avoiding the risk of RTAD. At present, our center has performed this d-TEVAR procedure combined with ascending aortic aortoplasty on four patients who were not deemed to be high-risk with an average follow-up duration of 3 months; none of the patients developed RTAD.

Although a large sample size and long-term follow-up observations are required to support our view, the addition of ascending aortic aortoplasty to d-TEVAR appears to provide a new approach to prevent RTAD and to enable the use of d-TEVAR in low-risk patients, which can thus reduce the challenges associated with aortic arch replacement.

Acknowledgements

The authors thank Zi-Ning Wu for his kind help on the schematic diagram making.

Conflicts of interest

None.