Taking the frozen elephant trunk technique to the next level by a stented side branch for a left subclavian artery connection: a feasibility study.

OBJECTIVES: Our goal was to develop a modified frozen elephant trunk (FET) prosthesis with a stented left subclavian artery (LSA) side branch for LSA connection and to perform preclinical testing in a human cadaver model. METHODS: We measured aortic diameters, distance between and diameters of supra-aortic vessels and the distance from the LSA offspring to the level of the left vertebral artery offspring in 70 patients. Based on these measurements, a novel FET prosthesis was developed (Cryolife/Jotec, Hechingen, Germany) featuring a stented side branch for an intrathoracic LSA connection. The feasibility and ease of implantation were tested in 2 human cadaver models at the Anatomical Institute of the Medical University Graz. A covered stent graft (Advanta V12™ by Atrium Medical Corp., Hudson, NH, USA) was used for an LSA extension. RESULTS: Accurate deployment of the novel FET prosthesis with anatomical orientation of the stented side branch towards the LSA ostium followed by consecutive stent graft deployment was feasible in both cases. Proximalizing the distal anastomosis level from zone 3 to zone 1 not only diminished the complexity of the procedure but substantially facilitated the completion of the distal anastomosis. A 2.5-cm long extension stent graft was sufficient to seal to the LSA and to maintain left vertebral artery patency in both cases. CONCLUSIONS: This initial study in human anatomical bodies could demonstrate the feasibility of implanting a newly designed FET prosthesis. This evolution of the FET technique has the potential to substantially ease total aortic arch replacement by proximalization of the distal anastomosis into zone 1 and by shortening spinal and lower body hypothermic circulatory arrest times via a stented side branch to the LSA. This direct connection enables early restoration of systemic perfusion.

Evaluation of the downstream aorta after frozen elephant trunk repair for aortic dissections in terms of diameter and false lumen status.

OBJECTIVES: To analyse the clinical outcomes of surgical repair of DeBakey type I and III aortic dissection (AD) by using the frozen elephant trunk (FET) technique, and to evaluate the postoperative behaviour of the residual aorta. METHODS: In total, 27 consecutive patients underwent treatment of the thoracic aorta for AD with the FET technique in a tertiary-care hospital in Vienna/Austria between 2005 and 2012, and were enrolled in this case series study. All operations were performed under circulatory arrest and bilateral antegrade cerebral perfusion. During the follow-up, a clinical examination was performed as well as aortic diameters and false lumen (FL) patency evaluated by computed tomography (CT) imaging at following levels: pulmonary bifurcation, diaphragm and coeliac trunk. RESULTS: The mean age of the patient cohort was 56 ± 12 years; 21 patients were male. Twenty-two (82%) and 5 (18%) patients presented with DeBakey type I and type III AD, respectively. The hospital mortality rate was 7% (2/28); 2 patients died due to non-aortic-related reasons during a follow-up period of 48 ± 26 months. Three (11%) patients had a stroke, and 2 (7%) a spinal cord injury. The follow-up CT scans revealed FL thrombosis in 96% of the patients at the level of the pulmonary bifurcation (P < 0.001). Distal to the stent graft, at the level of the diaphragm and coeliac trunk, FL patency was observed in 52% (P = 0.1) and 78% (P = 0.6) of the patients, respectively. The true lumen of all analysed aortic segments increased significantly while the mean aortic diameter remained stable. CONCLUSIONS: Compared with conventional surgery for extensive ADs, the FET technique provides a high rate of FL thrombosis of the thoracic aorta.