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Page 6 of 11 Faggion Vinholo et al. Vessel Plus 2024;8:11 https://dx.doi.org/10.20517/2574-1209.2023.150

[47]
influence the timing and approach of intervention . Further, occlusion may be dynamic or static. Dynamic
occlusion is the result of the intimal flap reversibly and intermittently prohibiting blood flow to a vessel
branch, either due to collapse of the true aortic lumen or prolapse of the intimal flap into the vessel branch.
Conversely, static occlusion may occur when the dissection extends into the vessel branch, often causing
thrombosis . The former may be reversed with the reestablishment of antegrade flow through the true
[48]
lumen, whereas the latter will remain occluded without intervention on the vessel branch itself.

There are three primary approaches to address malperfusion in ATAAD: (1) early open surgical repair of
the ascending aorta; (2) early endovascular reperfusion via distal fenestration or stenting followed by open
surgical repair; and (3) early thoracic endovascular aortic repair (TEVAR) followed by open surgical repair,
which is emerging as a promising option. In general, early open surgical repair is favored in cases where
malperfusion is due to dynamic occlusion, whereas early endovascular reperfusion may be more strongly
considered in cases with static occlusion or treatment delays . The descending and abdominal aorta may
[45]
be further intervened upon endovascularly via TEVAR and its variations Provisional Extension To Induce
Complete Attachment (PETTICOAT) and Stent-Assisted Balloon-Induced Intimal Disruption and
Relamination of Aortic Dissection (STABILISE), where the former supplements the proximal stent graft
with a distal bare metal stent, and the latter additionally expands endovascular balloons within the stent
graft to obliterate the false lumen .
[49]
By the mechanisms described above, ATAAD can affect various vessel beds, potentially leading to any
combination of cerebral, spinal, coronary, renal, mesenteric, and extremity malperfusion. Each form of
malperfusion is approached differently, due to varying risks of morbidity and mortality, but the ideal
management of each remains uncertain. Nonetheless, early open surgical repair of the ascending aorta is
typically preferred for dynamic cerebral, spinal, coronary, and extremity malperfusion, and additional
interventions, such as carotid replacement, coronary ostial repair or bypass grafting and brachial or femoral
shunting, may be pursued as needed during surgery to reestablish end-organ perfusion . However, early
[48]
non-surgical reperfusion techniques can be considered in patients with static occlusion or as a temporary
bridge to surgery, including carotid artery stenting, percutaneous coronary intervention, and iliac
[48]
stenting .

There exists, however, more debate as to the appropriate reperfusion strategy in cases of mesenteric
malperfusion, and indeed, management options are continuing to evolve. Mesenteric malperfusion is
associated with particularly high mortality, as high as 70% to 100% , and consequently poses a clinical
[50]
dilemma on whether to approach reperfusion via immediate central aortic repair, early fenestration or
stenting of the descending aortic flap, or, more recently, performing TEVAR first and reassessing after
reperfusion. While medical management of mesenteric malperfusion may take the form of preoperative
volume resuscitation, with careful impulse control, medical therapy alone without intervention carries an
in-hospital mortality of 95% . For centers without the capacity to deliver any of the definitive interventions
[51]
for visceral malperfusion, it is reasonable to initiate temporizing medical management strategies and
transfer patients to a comprehensive aortic center .
[52]

Open central aortic repair has been the de facto treatment approach for ATAAD with mesenteric
malperfusion, as it reduces the risk of aortic rupture and can also reverse dynamic mesenteric occlusion.
However, given the high mortality associated with mesenteric malperfusion, intravascular fenestration and
stenting followed by definitive open surgical procedure, prioritizing end-organ perfusion restoration and
resolution of static occlusion is often considered [45,53] . In fact, for patients with mesenteric malperfusion who
undergo early fenestration and stenting, in-hospital and long-term survival after open repair has been found