Objectives: Recently, minimally invasive staged segmental artery coil-&plug embolisation (MISACE)
has been used in early clinical practice for spinal cord injury prevention prior to
open or endovascular aortic aneurysm repair. Optimal sequencing for MISACE occlusion
has not been investigated yet.
Methods: Twenty-five juvenile pigs were allocated into four groups. The first group had a
two-stage MISACE sequence starting with occlusion of all lumbar segmental arteries
in a first stage and the remaining thoracic segmental arteries in a second stage (N = 6). The second group received an alternating approach with occlusion of every second
segmental artery in a first and the remainder in a second stage (N = 6). The third MISACE sequence started at the watershed area between thoracic level
12 to lumbar level 2 in a first and the remaining arteries in a second stage (N = 6). A control group of seven animals received complete, open segmental artery occlusion
in a single stage. Neurological assessment, regional spinal cord tissue perfusion,
and histological examination were performed.
Results: Permanent paraplegia in the MISACE groups was observed in one animal of group 2 (alternating
sequence) and one animal from group 3 (watershed sequence). In the control group,
57% experienced permanent paraplegia. Group 1 (lumbar stage 1, remainder stage 2)
did not experience permanent paraplegia with no significant tissue damage (p < 0.05 group 1 vs. control). Regional spinal cord tissue perfusion in group 1 recovered
within 3 days after stage 2, whereas mean perfusion of the other groups remained significantly
lower compared with baseline (all p < 0.05). Animals from group 3 (watershed) did not suffer from any neurological impairment
after stage 1 MISACE with recovering regional perfusion after this stage; however,
recovery was worse after the second stage.
Conclusion: Minimally invasive staged repair results in less ischemic spinal cord injury and
favorable neurological outcomes compared with a one-stage approach. Although an occlusion
sequence starting with the lumbar segmental arteries in a first stage seems to be
the best two-stage approach with regard to neurological outcome and regional spinal
cord perfusion, an alternative approach starting with the watershed area in a first
stage and continuing the MISACE procedure in a second, third, or fourth stage may
also yield favorable results.
