2.2 INSTEAD-XL
Nienaber et al. extended the follow-up up period of the INSTEAD RCT to
five years. TEVAR was shown to reduce all-cause mortality (11.1% versus
19.3%; P=0.13), aorta related mortality (6.9% versus 19.3%; P=0.04),
and progression of dissection (27.0% versus 46.1%; P=0.04) relative to
OMT alone. Complete stent graft-induced FL thrombosis was observed in
90.6% of elective TEVAR cases at five years relative to 22.0% with OMT
only (P<0.0001). TEVAR was necessary in fourteen cases
randomized to OMT alone and seven additional stent grafts were required
in the TEVAR group. Furthermore, three TEVAR patients underwent open
surgical conversion as well as four cases in the OMT alone group. Events
leading to crossover or open conversion occurred more frequently with
OMT than after TEVAR. Overall, TEVAR conferred a long-term survival
advantage with the Kaplan–Meier curves demonstrating survival benefit
(all-cause and aorta-specific mortality) with TEVAR seen between 2 and 5
years (P=0.0003 and P=0.0005, respectively). The authors recommended
considering pre-emptive TEVAR in stable patients with suitable anatomy
to improve late outcomes [26].