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Advanced Neurology Rescue stenting in mechanical thrombectomy

have described the prevalence of symptomatic ICAS clots who underwent stent retriever thrombectomy.
in Europe, which ranges from 6.5% to 17.8% for acute Successful recanalization was achieved only in one of the
ischemic stroke LVOs treated with MT. 53-55 The incidence eight patients (12.5%). Two periprocedural adverse events
of IAD is unclear due to a lack of population-based studies were reported: vessel perforation of an M2 branch which
but IADs are likely less common than extracranial cervical was immediately coiled and inadvertent stent retriever
artery dissections. detachment while retrieving the clot. In a multicenter
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European retrospective study, Maurer et al. reported a
2.3. Pathophysiology 1.3% (40/2969) prevalence for calcified emboli and noted
Failure to achieve successful recanalization is caused by a less successful recanalization rates (mTICI >2b, 57.5%),
heterogeneous group of disease processes and procedural good functional outcomes (defined as a modified Rankin
events. ICAS causes acute ischemic stroke through Scale [mRS] 0 – 2, 26.5%), and 90-day mortality (55.9%)
multiple mechanisms including plaque rupture with in situ compared to other etiologies. 65
thrombosis (IST) and/or distal embolization, high-grade/
critical stenosis with hemodynamic impairment, and 2.4. Evidence supporting RS
branch occlusive disease. Development of atherosclerosis To date, RS has been examined in one randomized trial
involves a local inflammatory response that infiltrates the which has completed enrollment (NCT05122286).
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affected vessel, deposition of cholesterol and collagen, and Evidence from prospective and retrospective cohort
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secondary endothelial dysfunction. ICAS plaques are studies suggests a benefit for RS over non-stenting in both
heterogeneous with varying lipid content, mineralization, the anterior and posterior circulation. Stents provide an
and intimal proliferative fibrosis. Immune infiltration of attractive option for the failure of successful recanalization
the atherosclerotic plaque may degrade interstitial collagen, caused by multiple etiologies. In the case of ICAS-related
causing fibrous cap erosion and increasing the risk of occlusion, stents provide radial force against the stenotic
plaque rupture. Intraplaque hemorrhage and plaque region of the vessel wall or clot, respectively. In the case of
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neovascularization may also lead to increased plaque IAD, stents can displace intimal flaps away from the vessel
vulnerability. MT in the setting of ICAS is challenging lumen. In addition, drug-eluting stents may reduce local
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due to the high risk of iatrogenic plaque rupture, IST, inflammation and reduce the risk of restenosis.
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reocclusion, and distal embolization. In a meta-analysis
by Tsang et al., the intraprocedural reocclusion rate in the 2.4.1. Anterior circulation
ICAS group was 36.9% compared to 2.7% in non-ICAS Baek et al. compared an RS group with a non-stenting group
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group (OR 23.7 [6.96 – 80.7], P < 0.001), whereas another in patients with stentriever-failed anterior circulation LVO.
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meta-analysis reported that large vessel atherosclerosis was Seventeen patients were stented using the Solitaire-AB/
associated with higher odds of reocclusion after successful FR stentriever (n = 10) or Wingspan (n = 7), whereas 28
(mTICI >2b) EVT (OR 3.44 [1.12 – 10.61]). The high rate had no RS. A good outcome or mRS 0 – 2 at 3 months
of intraprocedural reocclusion may explain the reason that was achieved in 35.3% of the rescue stent group versus
ICAS constitutes the majority of refractory MT cases. 7.1% of the non-stent group. Symptomatic intracerebral

The lack of external elastic lamina may make intracranial hemorrhage (sICH) and mortality did not differ. Follow-up
arteries prone to sub-adventitial dissection. 60,61 IAD may magnetic resonance angiography/computed tomography
cause distal emboli or the formation of a mural hematoma, (CT) angiography at day 1 – 12 months showed patency in
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leading to complete occlusion of the artery. Moreover, the 16 out of 17 patients in the stent group.
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risk of further injury to the vessel wall during manipulation A retrospective study by Peng et al. examined a total
of the clot in MT is high, leading to worsening dissection of 90 patients with RS and 117 patients without RS after
and occlusion of the artery. refractory MT using propensity score matching. Good
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Thrombus composition can impact the success of functional outcome defined as 90-day mRS (0 – 2) was
endovascular therapy. Recalcitrant emboli or calcified significantly higher in matched patients with RS than in
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clots are composed of large amounts of calcium phosphate, those without RS (36.4% vs. 19.7%, P = 0.033), whereas
which renders the clots stiffer and less amenable to sICH (13.6% vs. 21.2%, P = 0.251) and mortality (31.9% vs.
conventional endovascular techniques. This can lead to 43.9%, P = 0.151) were not significantly different between
periprocedural adverse events such as vessel perforation the groups.
or failure of recanalization. Dobrocky et al. conducted The stenting and angioplasty in neurothrombectomy
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a retrospective analysis examining successful perfusion study was a retrospective and propensity score analysis of
outcomes in eight patients with calcified intracranial patients with anterior circulation LVO stroke and refractory

Volume 3 Issue 3 (2024) 3 doi: 10.36922/an.3950