Coil embolization of segmental arteries as a spinal cord protection strategy prior to complex endovascular repair of thoracoabdominal aorta

Spinal cord ischemia remains one of the most devastating complications in the repair of thoracoabdominal aneurysms, with incidences of up to 20–30% in extensive repairs. In this context, multiple protective strategies have been developed. Based on the concept of the spinal collateral network, selective embolization of segmental arteries (MISACE) consists of proximal occlusion with coils of intercostal and lumbar arteries within the territory that will be covered by the endograft, aiming to induce arteriogenesis and precondition spinal cord circulation prior to F/BEVAR.

This single-center retrospective study evaluated the safety and clinical impact of MISACE in patients undergoing F/BEVAR, comparing a contemporary cohort treated with MISACE (n=42, 2018–2023) with a historical cohort without MISACE (n=50, 2007–2018), totaling 92 patients with thoracoabdominal aneurysms (Crawford classification, predominantly extent I–III).

The primary endpoint was the incidence of in-hospital spinal cord ischemia following F/BEVAR, defined as the occurrence of any spinal neurological deficit (early or delayed, before or after 24 hours). Secondary endpoints included in-hospital mortality, stroke, length of hospital stay, and predictors of spinal cord ischemia.

Mean age was lower in the MISACE group (70 ± 9 vs 75.1 ± 5.8 years; P=0.003), with a higher prevalence of aortic dissection (36% vs 12%; P=0.014), and no significant differences in comorbidities or in the proportion of extensive aneurysms (extent I–III: 76% vs 80%; P=0.66). The MISACE procedure was technically successful in 100% of cases, performed in a single session in 95.2%, with a median of 3 arteries embolized and no associated neurological complications.

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Regarding outcomes, the incidence of spinal cord ischemia was significantly lower in the MISACE group (9.5% vs 30%; P=0.016), a difference that persisted in extent I–III aneurysms (8.6% vs 31.2%; P=0.027). No differences were observed in early events, but there was a significant reduction in delayed spinal cord ischemia (4.8% vs 20%; P=0.031). Rates of paraparesis/paraplegia, both transient and permanent, were lower in the MISACE group, although without reaching statistical significance.

In-hospital mortality did not differ between groups (7.1% vs 12%; P=0.50), nor did stroke incidence (0% vs 10%; P=0.06), while hospital stay was significantly shorter in the MISACE group (7 vs 11 days; P=0.022). During follow-up, no new spinal cord ischemia events were recorded, and survival was similar at 1 and 3 years.

Conclusion: Segmental artery embolization as a safe and effective spinal cord protection strategy in complex aortic repair

In conclusion, the MISACE strategy is feasible and safe, and is associated with a lower incidence of spinal cord ischemia (particularly delayed), without an increase in adverse events. While these results support its use as part of a multimodal strategy, they require confirmation in prospective randomized studies.

Original Title: Minimally invasive segmental artery coil embolization for spinal cord ischemia prevention prior to fenestrated/branched endovascular aortic repair.