Hybrid arch frozen elephant trunk repair: evidence from the Canadian Thoracic Aortic Collaborative

Abstract

Background: The frozen elephant trunk (FET) technique has become an increasingly popular strategy for aortic reconstruction in the setting of extensive thoracic aortic aneurysms or dissections. The objective of this study is to report on the Canadian experience with the FET technique in both the elective and emergent settings. Methods: A total of 167 consecutive patients (mean age 65±13 years, 30% female, 25% re-operation) underwent elective (70%) and non-elective (30%) aortic arch reconstruction with the FET technique between May 2008 and October 2019 in six centers of the Canadian Thoracic Aortic Collaborative (CTAC).In-hospital clinical endpoints and early imaging endpoints were prospectively collected and analyzed.Results: All 167 patients underwent successful FET implantation. In-hospital mortality occurred in 14 patients (8%), stroke occurred in 22 patients (13%) and temporary and permanent spinal cord ischemia (SCI) occurred in 6 (3.6%) and 3 (1.8%) patients, respectively. Prolonged mechanical ventilation was required in 35 patients (21%), renal failure requiring dialysis in 14 patients (8%) and atrial fibrillation in 59 patients (36%). The median hospital and intensive care unit (ICU) lengths of stay were 3 [interquartile range (IQR):1, 6] and 10 (IQR: 7, 17) days, respectively. The rate of type 1A endoleak was 3.6%, with the lowest rate in patients who underwent a total arch replacement with a hybrid FET graft (0%) and the highest among patients who had a hemiarch with antegrade thoracic endovascular aortic repair (TEVAR) deployment (25%).The rate of other types of endoleak and stent complications was comparatively low. Conclusions:The early CTAC experience with the FET operation demonstrates technical feasibility and good early clinical outcomes in elective and emergent patients. Further analysis is required to explore variations in technique and their potential impact on early and late outcomes.

The Evolving Role of Hybrid Arch Repair

“…The Canadian experience with hybrid arch repair (the majority of which involved off-the-shelf hybrid FET devices) included 167 patients with a mean age of 65 ± 13 years, 30% of whom underwent urgent or emergent surgery. 34 In this cohort, there was an 8% in-hospital mortality and 13% stroke rate. Permanent spinal cord ischemia occurred in 1.8% of patients.…”

Kinking of Frozen Elephant Trunk Hybrid Prostheses: Incidence, Mechanism, and Management

“…Here, the patient's 2- and 2.5-year follow-up CTA revealed graft kinking with proximal migration of the endograft portion of the FET, resulting in new thrombus formation, thus necessitating endovascular reintervention which was performed successfully. Lastly, 2 relatively large studies using Thoraflex Hybrid did not observe any cases of graft kinking amongst their study population of 92 and 167 patients, respectively ( 17 , 24 ).…”

“…For example, in comparison to other hybrid devices, Thoraflex Hybrid exerts a lower radial force onto the aortic walls. Although this is associated with positive outcomes in acute pathology, in chronic dissection this amplitude and force may cause compression and kinking of the stent, potentially introducing the need for ballooning and further intervention ( 24 ). Frozenix, on the other hand, was reported to cause functional obstruction of the graft due to impingement of the distal end of the prosthesis with the intimal flap.…”

“…Further benefit yielded by the intraoperative ultrasound scan is highlighted in a different study by Baraki et al ( 26 ), where failure to advance the guidewire and the introducer system resulted in perforation of the aorta. The Canadian Thoracic Aortic Collaborative also suggested using transoesophageal echocardiography to ensure correct stent placement with no kinking ( 24 ).…”

Commentary: The elephant in the room: Routine arch repair for acute dissection?

“…In centers of excellence, an FET repair can be performed with good outcomes, but increased risk of spinal cord injury remains paramount, particularly when deployed beyond T8. 1 , 2 Other complications of FET include endoleaks, stent graft–induced new entry tears, endoluminal thrombus formation with subsequent embolism, and prosthetic graft infection.…”