Total aortic arch replacement without deep hypothermic circulatory arrest in type A aortic dissection: Left axillar artery for arterial cannulation

Abstract

Objective: Total aortic arch replacement (TAR) necessitates hypothermic circulatory arrest (CA). The frozen elephant trunk technique (FET) additionally requires commercial hybrid grafts. Herein we describe a novel modified FET technique without CA using standard grafts thanks to left axillary artery (LAxA) cannulation in patients with acute type A aortic dissection.

Methods: LAxA anastomosis is made first using a homemade debranching graft, and cardiopulmonary bypass is initiated, followed by anastomoses of left common carotid and innominate arteries. The rest of the operation is performed with complete cerebral perfusion. Following replacement of ascending aorta/root, cardiac reperfusion is started using a root cannula which continues throughout the procedure. Distal arch anastomosis is performed clamp-on, allowing lower body perfusion via left subclavian artery. Lower body perfusion is interrupted for 5 to 8 minutes to deploy an endograft to complete a modified FET. Following cannulation of distal arch graft, perfusion of distal aorta is restarted, and all three grafts are incorporated to construct a neo-ascending aorta and arch.

Results: Between December 2018 and May 2022, 38 patients underwent TAR without operative mortality. Hospital mortality was %15.7, and spinal cord ischemia and stroke were not encountered in surviving patients. The mean lower body CA time was 7.2 ± 2.8 minutes.

Conclusions: TAR using standard endografts without CA is possible with LAxA cannulation. To perform a FET, only a short interruption of lower body circulation is sufficient to deploy an endograft, also improving hemostasis of distal anastomosis. Further studies are required with a higher number of patients to evaluate the efficiency of this novel technique.

Keywords: circulatory arrest; deep hypothermia; frozen elephant trunk; left axillary artery cannulation; total arch replacement; type A aortic dissection.

Trifurcated debranching graft and left axillary artery cannulation before debranching.

Figure 1

Homemade trifurcated debranching graft, its usage during the commencement of CPB and debranching procedure. A, Trifurcated graft with a perfusion arm, limb A to LSA, limb B to LCCA, limb C to IA and D perfusion arm. B, Commencement of CPB: After completion of LAxA anastomosis, a clamp is applied to limb A just proximal to the perfusion arm, and commencement of CPB, LSA is left intact for perfusion of the rest of the body. C, LCCA Debranching: following limb B anastomosis to LCCA, a clamp is applied to the body of the bifurcated part to allow perfusion of LCCA and aorta from TFG. D, IA Debranching: following limb C anastomosis to IA, a clamp is applied to the body of the TFG to allow perfusion of IA, as well as LCCA and aorta. CPB, Cardiopulmonary bypass; LSA, left subclavian artery; LCCA, left common carotid artery, IA, innominate artery; LAxA, left axillary artery; TFG, trifurcated debranching graft.

Figure 2

Distal arch anastomosis without interrupting distal body perfusion. A clamp-on anastomosis technique is selected to minimize visceral ischemia and the need for hypothermia. Using CET and modified FET generates a watertight anastomosis via “intraluminal bypass” concept. A, An approximately 4-cm part of Dacron graft is invaginated, and the folded edge is sutured to zone 1 while zone 2 is clamped; meanwhile, lower body, heart, and brain are perfused via LSA, root cannula, and TFG, respectively. B, A CET is created to serve as a robust landing zone for deploying a TEVAR. A brief lower-body circulatory arrest is mandatory for open interventions in distal aorta. XCl at zone 2 is removed and applied to LSA while CPB flow is reduced and titrated accordingly to right upper extremity blood pressure and NIRS levels. Invaginated part of the DAG is pushed down to the distal aorta to attain CET. C, Achieving a watertight anastomosis via a modified FET. An endograft is deployed starting 2 cm proximal to the anastomosis and is extended to the distal aorta; the suture line is covered inside to be isolated from blood flow which minimizes anastomotic bleeding. Interruption of lower body circulation usually takes 5 to 8 minutes. FL, False lumen; TL, true lumen; CET, classic elephant trunk; FET, frozen elephant trunk; LSA, left subclavian artery; TFG, trifurcated debranching graft; TEVAR, thoracic endovascular aneurysm repair; XCl, crossclamp; NIRS, near-infrared spectroscopy; DAG, distal arch graft.

Figure 3

Incorporation of 3 grafts. Following ligation of LSA to prevent a type 2 endoleak, an arterial cannula is connected to the DAG and lower-body perfusion is restarted. While complete body perfusion is commenced, an appropriate-size hole is generated at the proximal part of the DAG, and the proximal tip of TFG is sutured to the DAG. TAR is completed with anastomosis of the proximal end of the DAG to ascending aortic graft. FL, False lumen; TL, true lumen; LSA, left subclavian artery; DAG, distal arch graft; TFG, trifurcated debranching graft; TAR, total aortic arch replacement.

Figure 4

Overall appearance after completion of TAR. CET, Classic elephant trunk; TAR, total aortic arch replacement; FET, frozen elephant trunk; TL, true lumen; FL, false lumen.

Figure 5

Pre- and postoperative 3-day reconstructions of CTAs and intraoperative view after completion of TAR. CTA, Computed tomography angiography; TAR, total aortic arch replacement.

Figure E1

A forceps is used for invaginating a 3-4 cm long segment of the Dacron graft. A side arm for arterial cannulation could be sutured beforehand to shorten lower body circulatory arrest time, or arterial cannulation can be done following the placement of a purse suture (Video 1).

Figure E2

Cross sections after completion of TAR. A, Proximal landing zone located in the DAG. B, Proximal landing zone located in CET. C, Endograft inside the distal thoracic aorta, which expands true lumen and covers distally located re-entries. TAR, Total aortic arch replacement; DAG, distal arch graft; CET, classic elephant trunk.