Total Arch Replacement With a Novel Dual Stent Device

Introduction 

On behalf of the Department of Cardiothoracic Surgery at St. James’s Hospital, two cases are presented to demonstrate the authors’ technique of aortic arch replacement using a novel frozen elephant trunk hybrid arch device. 

The left subclavian artery can present particular challenges during frozen elephant trunk procedures, as it can often be deep, posterior, and displaced by aneurysm. The Neo EDE is a novel dual stent frozen elephant trunk device with an integrated left subclavian artery stent. Each device is custom-made for the patient. Benefits of this device include avoiding the need to re-implant the left subclavian artery, which decreases deep hypothermic circulatory arrest, cardiopulmonary bypass, and overall operating times. 
 
Case 1  

Background 

Case 1 is that of a 61-year-old female who presented with a type B aortic dissection in 2016 and was initially managed conservatively. Surveillance computed tomography (CT) demonstrated an the aneurysm increasing in size and she was referred for surgical management. Her past medical history was significant for hypertension, hyperlipidaemia, osteoarthritis, and a left total hip replacement. 
 
Preoperative echocardiography demonstrated a trileaflet aortic valve without aortic stenosis or regurgitation, and a preserved ejection fraction. Preoperative CT demonstrated a type B aortic dissection with the flap originating just distal to the left subclavian artery, extending to the common iliac bifurcation and into the left common carotid artery. The larger false lumen supplied the coeliac trunk and left renal artery. The descending aortic aneurysm was 52 mm. 
 
The surgical approach consisted of arterial cannulation using a 22 Fr ascending aortic cannula and direct cannulation of the innominate artery. A two-stage venous cannula through the right atrium and a right superior pulmonary vein vent were placed. A branch-first technique was employed in which the innominate and left common carotid arteries were debranched onto a Y-graft and perfused separately. The arch was resected to zone 2.  

As this case involved a chronic type B aortic dissection, a femoral guidewire for the main body stent was passed into the true lumen under transesophageal echocardiography (TOE) guidance. This was an optional step and not a requirement for using the Neo EDE device but is advisable in patients with chronic aortic dissection to ensure stent deployment in the true lumen. An antegrade left subclavian artery guidewire was used. Alternatively, a retrograde left subclavian artery guidewire may be passed through the radial or brachial artery. 

Video 

This video began with the initiation of deep hypothermic circulatory arrest. The ascending aorta had been resected and replaced with an interposition graft at the sinotubular junction. The innominate and left common carotid arteries were debranched onto a Y-graft and perfused separately.  

The true lumen guidewire was retrieved.  

It was crucial to measure the correct distance between the left subclavian artery origin and the device-to-arch anastomosis site to ensure correct positioning of the left subclavian artery stent. 

An anterograde left subclavian guidewire was inserted under direct vision.  

The true lumen aortic guidewire was passed into the delivery system, followed by the left subclavian artery guidewire. The correct orientation of the device was confirmed, and the delivery system was advanced into the aorta and left subclavian artery.  
 
The aortic stent was deployed, followed by the left subclavian artery stent. It was vital to deploy the aortic stent first to prevent migration of the left subclavian artery stent prior to deployment. It was important to take time and directly visualize that the left subclavian artery delivery system was retracted before removing the device over the guidewires. 
 
The left subclavian artery was then cannulated directly with a cerebral perfusion cannula, the balloon of which could be used to further expand the stent.  
 
The distal anastomosis was performed in two layers. Initially, a layer of continuous 3-0 Prolene was used, reinforced with Teflon. Distal perfusion was then restarted through the perfusion branch of the graft before completing a second layer of horizontal mattress 2-0 Ethibond.  
 
The proximal graft-to-graft anastomosis was performed, followed by anastomosing the Y-graft to the ascending aortic graft. 

Outcome 

Postoperative CT demonstrated satisfactory positioning of the aortic and left subclavian artery stents, with positive remodeling of the false lumen. The patient was discharged to convalescence and was seen in the clinic six weeks postoperatively, recovering well. 

Case 2  

Background 

Case 2 is that of  a 68-year-old male who presented with a type B aortic dissection in January 2024. This case was initially managed conservatively, but due to an increasing descending aortic aneurysm size and persistent pain, the patient was referred for surgical management. His past medical history was significant for hypertension, obstructive sleep apnea, and type 2 diabetes mellitus. 
 
Transthoracic echocardiography demonstrated a trileaflet aortic valve without stenosis or regurgitation, and a preserved ejection fraction. A CT of the aorta demonstrated a type B aortic dissection with the flap arising at the origin of the left subclavian artery and extending just past the coeliac artery, which was supplied by the false lumen. The initimal tear was visible in the proximal descending aorta. The descending aortic aneurysm measured between 52 and 55 mm. 
 
A similar surgical strategy was used as in Case 1, with the innominate artery and left common carotid arteries debranched onto a Y-graft and perfused separately.  
 
As in Case 1, due to the chronic aortic dissection, a femoral guidewire was passed into the true lumen under TOE guidance to ensure true lumen deployment of the main body stent. 
 
Video 

This video began following debranching of the left common carotid and innominate arteries, replacement of the ascending aorta, and initiation of deep hypothermic circulatory arrest. It was crucial to measure the distance of the left subclavian artery to the collar anastomosis site to ensure appropriate placement of the left subclavian artery stent.  
 
A left subclavian artery guidewire was passed antegradely under direct vision.  
 
The guidewires were passed through the delivery system, and the delivery system was orientated and advanced into position. 
 
Again, the importance of deploying the aortic stent prior to the left subclavian stent is emphasized to prevent migration and ensure that the left subclavian artery stent is fully deployed prior to removing the device over the guidewires.  
 
The distal anastomosis was completed in a similar fashion using a layer of continuous 3-0 Prolene reinforced with Teflon. Distal perfusion was again reinstated through the perfusion limb of the graft.  
 
The proximal graft-to-graft anastomosis was performed, followed by the Y-graft to ascending aorta anastomosis. 
 
Outcome 

A CT scan of the aorta performed six weeks postoperatively showed satisfactory positioning of both stents, positive remodeling of the false lumen, and no evidence of endoleak. The patient was discharged directly home and was recovering well when seen at the clinic six weeks postoperatively. 
 
Conclusion 

Two cases of the frozen elephant trunk Neo EDE device were presented. From the authors’ experience, it was found that the technical aspects of using the device were straightforward, with an intuitive delivery system. Both cases demonstrated good clinical and radiological outcomes. Notably, preoperative planning was crucial when using the device, with particular attention given to the site of the collar anastomosis to the arch.  

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