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Page 6 of 16 Gomes et al. Vessel Plus 2023;7:24 https://dx.doi.org/10.20517/2574-1209.2023.60

SCI risk reduction of the staged strategy, either for open or endovascular repair of TAAA.

Minimally invasive segmental artery coil embolization
Minimally invasive segmental artery coil embolization (MISACE) is a technique aimed to provide a
preconditioning to ischemia prior to the TAA or TAAA repair. The rationale behind this strategy is to
improve spinal cord vascularization through neo-angiogenesis before the index procedure, either open or
endovascular. Geisbush et al. demonstrated in a swine model that the coiling of 2-4 segmental arteries
significantly prevented paraplegia after extensive thoracoabdominal aneurysm repair . Etz et al. described
[68]
the first-in-man successful experience with this technique performed in two patients: one planned for an
open repair of a type III TAAA, and the second planned for an endovascular repair of a type II TAAA .
[69]
Both patients developed no neurologic injuries either after MISACE or the TAAA repair. Branzan et al., in a
study including 57 TAAA cases reported the embolization of 77.7% of the segmental arteries and no
[70]
occurrence of SCI using the MICACE technique . According to a study published by Addas et al., the
imaging planning prior to the MISACE technique consists of observing anatomical landmarks close to the
[71]
site of segmental arteries’ origin to assist in selecting target arteries during the procedure . Preoperative
images also guided coil sizing, fluoroscopy positioning and angulation. The authors utilized the
transfemoral approach in all the 17 patients included in their study. Once the target vessel was selected, the
coils were deployed in the proximal section of the chosen segmental artery, proximal to its branching point.
The mean time window between the MISACE and the TAAA repair was 51.2 days (5-110 days).

Although the studies mentioned above provide encouraging results, numerous complications can occur in
the context of the MISACE technique, such as the incomplete occlusion of the targeted segmental arteries
usually associated with the use of antiplatelet therapy or anticoagulants, loss of coils in the aorta, and the
most severe of all, SCI. In addition, anatomical challenges related to the segmental arteries, such as large
vessel diameter and tortuosity, and the long duration of these procedures associated with high contrast
volume administration should be considered before the application of the MISACE technique . A clinical
[71]
trial that started in Europe in November 2018, with a completion date estimated for March 2023, will assess
[72]
the clinical safety and efficacy of the MISACE procedure .

PERIOPERATIVE STRATEGIES FOR SCI PREVENTION: LUMBAR DRAIN UTILIZATION,
THE ROLE OF NEUROMONITORING AND INTRAOPERATIVE HEMODYNAMICS
MANAGEMENT
Spinal drain utilization as a strategy for SCI prevention
The perfusion of the spinal cord relies on numerous factors including mean arterial pressure (MAP),
cerebrospinal fluid pressure (CSFP), and central venous pressure (CVP. Spinal cord perfusion pressure
(SCPP) is directly proportional to the MAP and inversely proportional to the CSFP and CVP,
[31]
corresponding to the neuraxial outflow pressure . Coselli et al., in a randomized controlled trial including
145 TAAA patients submitted to open repair, demonstrated an 80% relative risk reduction of postoperative
deficits in the group with CSF drain placed preoperatively . Suarez-Pierre et al., in a retrospective analysis
[73]
of 4,287 patients included in the TEVAR module of the Vascular Quality Initiative (VQI), concluded that
[74]
preoperative spinal drainage placement significantly reduced the risk of SCI .
However, Aucoin et al., in a study including eight of the Principal Investigators of the US Aortic Research
Consortium (US-ARC) [75,76] , discuss that the indications of prophylactic CSF drain placement are evolving
due to potentially severe complications related to drain placement. These authors recommend the
placement of a preoperative drain in Type I-III TAAA cases, in patients with prior history of aortic
infrarenal repair, cases with “shaggy aorta”, hypogastric artery abnormalities (unilateral occlusion or