False lumen thrombosis and aortic remodelling
The extent of FL thrombosis and positive aortic remodelling following
FET implantation can be considered an indicator of therapeutic efficacy
of the FET stent. Coverage and rectification of intimal tears in AAD
serve to improve distal TL integrity and limit FL patency, thereby
promoting thrombosis and obliteration, particularly in the locality of
the FET stent.25 In cases of chronic aortic
dissection, proximal FL thrombosis around the stented aorta is
associated with improved distal positive remodelling, while negative
aortic remodelling is associated with reintervention in the distal
aorta.25 Jakob and colleagues, in their review of the
E-vita Open hybrid graft for Z-2-FET and Z-3-FET, report complete
exclusion of aortic disease and positive remodelling around the graft
region in 94% (n=167) and 92% (n=163) of AAD patients treated with
Z-2-FET, but that 82% (n=145) of such patients were also found to have
residual disease distal to the FET stent.11Interestingly, similarly mixed results were reported by both Yamamotoet al. and Jakob et al. in their respective reviews on
Z-0-FET.16, 17 Jakob and colleague’s 3-zone Z-0-FET
prosthesis procedure showed thrombosis of the FL around the aortic arch
and DTA in only 40% (n=2) and 60% (n=3) of cases respectively, while 3
of 6 patients reviewed demonstrated residual arch FL patency while
remaining clinically stable.17 Yamamoto et al.highlighted that thrombosis of FLs of the aortic arch, DTA, and
abdominal aorta was achieved in 74.1% (n=80), 29.6% (n=32), and 5.5%
(n=6) of cases respectively.16 Interestingly, 3%
(n=3) patients demonstrated re-opening of the FL around the coeliac
arteries following Z-0-FET repair.16 Undoubtedly, the
clinical factors surrounding the effect of FET on FL thrombosis and
aortic remodelling is complex and multifactorial – yet Yamamoto and
colleague’s results are promising, particularly for cases of DeBakey
Types I and II AAD.