Evolution of the FET
Started as “Essen I Prosthesis”, the hybrid prosthesis was first
commercially available as Evita Open (Jotec®, Hechingen, Germany) in
2005 [3]. With the non-availability of the hybrid prosthesis in USA,
surgeons have explored different options - antegrade delivery of a stent
graft during deep hypothermic circulatory arrest (DHCA)[4] or by
creating a scallop in the endoprosthesis to accommodate the supra aortic
arch vessels [5]. A major concern of FET was the higher incidence of
paraplegia compared to the classical elephant trunk. This prompted the
surgeons to reduce the length of the stent-graft and / or proximalize
the distal anastomosis from zone 3 to zone 2 [6]. This further paved
the way for technical advancements wherein surgeons introduced a
fenestration of the stent graft for the left subclavian artery (LSA)
[7] or a side branch to the LSA in the hybrid prosthesis. Sometimes,
surgical efforts to reimplant the very distal and posterior left
subclavian artery included the intra-thoracic aortic-subclavian bypass,
aortic-axillary bypass and extra-thoracic carotid-subclavian bypass
[8]. This warrants an additional incision in the left
infraclavicular or supraclavicular region. These advancements entails
the adjustments of the extracorporeal circuit [6].Though with the
advancements, the FET still requires DHCA with selective antegrade
cerebral circulation (SACP), restricting the procedure to be performed
by surgeons familiar with aortic arch surgery. To overcome this, newer
technical devices developed by JOTEC/CryoLife, Kennesaw, USA are being
introduced aiming to reduce complexity enabling surgeons to perform FET
in zone 0 or 1 as opposed to zone 3 (Fig.1)