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Page 8 of 16 Gomes et al. Vessel Plus 2023;7:24 https://dx.doi.org/10.20517/2574-1209.2023.60

epidural space to infuse precooled saline. The epidural cooling was initiated 30 min before aortic clamping,
maintaining the temperature at 25 °C. Moreover, Bobadilla et al. suggest that mild intraoperative
hypothermia, keeping body temperature between 32-35 °C, could improve spinal cord ischemic tolerance
[86]
and aid in preventing SCI .

As for the pharmacological options that would potentially help, the use of mannitol (18% mannitol, 0.5 g/kg,
infusion rate: 300 mL/h) can contribute to reducing the CSF pressures, as previously demonstrated in the
literature [87,88] . Among the Principal Investigators of the Aortic Research Consortium, doses between 12.5
[75]
and 25 g of mannitol have been used intraoperatively during F/BEVAR procedures . An experimental
study also suggests that mannitol can function as a free radical scavenger; therefore, it would potentially
contribute to reducing the risk of spinal cord ischemic injury in the context of TAA and TAAA repair.
Naloxone is another drug that could be favorable in this context. Kunihara et al. observed that the
intraoperative administration of this medication (1 microg/kg/h) has been shown to reduce the levels of
excitatory neurotransmitters in the CSF, such as glutamate, which is significantly elevated in patients that
presented SCI after TAA and TAAA repair, and can be considered an independent predictor of SCI in the
[89]
context of aortic surgery .

Perioperative glucose monitoring has been shown to decrease the risk of neurological deficits related to
spinal cord ischemia. Hiramoto et al., in a study involving individuals who underwent branched
endovascular aneurysm repair (BEVAR), reported a reduced incidence of postoperative lower extremity
weakness in patients who were prescribed a perioperative insulin infusion protocol. The authors suggest
that tight glycemic control should be considered for patients who will be submitted to extensive aortic
coverage and therefore are at higher risk of SCI .
[90]

Finally, the role of steroids deserves attention, as their actions on the recovery after SCI have been
[91]
extensively debated in the literature. Laschinger et al. observed encouraging results in an experimental
model in which animals submitted to aortic cross-clamping were analyzed . The ones that received
[92]
methylprednisolone intraoperatively and a second dose postoperatively presented no clinical evidence of
neurological deficit, contrasting with the 67% incidence of permanent paraplegia observed in a control
group that underwent the same duration of cross-clamping but did not receive the drug. Prior publications
on SCI prevention in the context of aortic surgery suggest the intraoperative administration of steroids as
part of a protocol of SCI prophylaxis. Bobadilla et al., in a study including 94 patients submitted to TEVAR
mainly for the treatment of aneurysms or dissections, reported an incidence of SCI as low as 1.1% and
attributed these results to the implementation of a proactive spinal cord protective protocol, which included
the administration of methylprednisolone 30 mg/kg . Similarly, Acher et al. observed a very low incidence
[86]
of SCI (0.65%) in 155 patients submitted to TEVAR, encouraging the simultaneous use of numerous spinal
cord protective measurements, including the intraoperative administration of methylprednisolone
30 mg/kg . Pasqualucci et al., in a study including 50 patients submitted to endovascular repair of TAAA,
[93]
reported the use of high doses of epidural steroids just before anesthesia induction, and observed 5 cases of
temporary neurological deficit, all of them completely reversed up to the fifth postoperative day .
[94]
Although it could be challenging to precisely describe the steroids' contribution to the overall spinal cord
protection strategy in the context of aortic surgery, many successful published protocols include the use of
these drugs. However, there is no consensus to date recommending the use of steroids as a prophylactic or
rescue tool for SCI in the context of aortic surgery.