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Page 10 of 16 Trahanas et al. Vessel Plus 2022;6:49 https://dx.doi.org/10.20517/2574-1209.2021.125

scope of this paper, but are well described in the surgical literature [21,22,32,37] . A European study compared
[37]
DHCA to LHB and found no difference in 30-day survival or major complications . The most impactful
[9]
[38]
procedural factor influencing patient outcome is the extent of resection and likely surgeon experience .
At our institution, the preference is for full CPB with DHCA for all Extent II CTBAD TAAA cases, as well
as Extent I cases involving the distal aortic arch, as this allows for a higher degree of organ protection and
intraoperative flexibility and avoids the need for cross-clamp of the more proximal aortic arch. Additionally,
we prefer direct distal aortic cannulation in this scenario rather than femoral arterial cannulation, to
minimize the risk of retrograde embolization of chronic thrombus from the false lumen. We place
preoperative lumbar drains the day prior to surgery in all patients with planned distal anastomosis below
[32]
the level of T6 . Somatosensory and motor evoked potentials, as well as electroencephalography, are used
for neurophysiologic intraoperative monitoring . While other authors succeeded in using islands of the
[39]
aorta to reimplant the visceral vessels , we prefer a side branch technique using a multi-branch Dacron
[22]
[39]
graft to eliminate the risk of late patch aneurysm formation . Dominant intercostal and lumbar arteries are
reimplanted for spinal cord protection in nearly all cases using individual 8 mm side grafts to again avoid
the risk of late patch aneurysm . For Extent III and select Extent IV TAAA, including those developing late
[21]
after prior TEVAR, we use LHB with full heparinization, which allows the use of an oxygenator and
cardiotomy suction.

Hybrid intervention
Hybrid procedures for CTBAD are diverse and can be tailored to the anatomy of a particular patient. Most
commonly, disease in the ascending aorta and arch is treated with open surgery, followed by subsequent
stent grafting of the remaining disease in the descending aorta. Procedures such as types I and II/III hybrid
arch repair (HAR) [Figure 6] allow the extent of open surgical resection to be limited to the proximal aorta
at the initial procedure, thus limiting the morbidity and allowing for a less invasive endovascular second
[40]
stage, which avoids the risks of open DTA/TAAA repair . The frozen elephant (FET) is another alternative
and can be considered a variant of type III HAR . It involves the replacement of the ascending aorta and
[41]
part or all of the arch, with the deployment of a thoracic endograft into the DTA under HCA. The endograft
is then incorporated into the distal anastomosis of the open surgical graft used to replace the arch . This is
[41]
all done in a single procedure and carries a risk of spinal cord ischemia of approximately 5% or higher in
[42]
most series , which is the major disadvantage of the FET approach. However, our institutional preference
is a staged approach utilizing type II HAR with first stage open proximal aortic repair followed by second
stage completion TEVAR during a single hospital stay. This preference stems from the differing
postoperative management strategies following open proximal aortic repair and TEVAR. Specifically, after
open proximal aortic repair, lower blood pressures are preferred in the early postoperative period to reduce
bleeding and anastomotic complications, whereas after TEVAR, higher pressures are preferred to optimize
spinal cord perfusion pressure and minimize the risk of spinal cord ischemia [27,41] .

Hybrid procedures may also be used to treat aneurysmal degeneration of the thoracoabdominal aorta. The
visceral vessels are debranched via a laparotomy, and the thoracic and abdominal aorta are then treated with
stent grafting [9,21,43,44] . This is a potential option for elderly and high-risk patients not suited to open repair
and can be conducted in a staged fashion . A previous study from our institution demonstrated no
[44]
difference in the rate of paraplegia or 1-year mortality between hybrid and open TAAA repair, but with a
higher rate of re-intervention and dialysis in the hybrid group . Having the capability to perform a wide
[43]
range of open and endovascular aortic interventions allows customization of the procedure to the needs and
characteristics of the patient and their disease .
[40]