Intentional Stent Stenosis to Prevent Hyperperfusion Syndrome after Carotid Artery Stenting for Extremely High-Grade Stenosis

Abstract

BACKGROUND AND PURPOSE: Intracranial hemorrhage due to hyperperfusion syndrome is a severe carotid artery stent placement complication of extremely high-grade stenosis, causing hemodynamic insufficiency. To prevent hyperperfusion syndrome, we attempted intentional residual stent stenosis and implemented "gentle" carotid artery stent placement, defined as carotid artery stent placement using a closed-cell stent coupled with slight balloon predilation, without balloon postdilation. Gradual stent expansion was expected. We investigated the incidence of hyperperfusion syndrome and long-term outcomes after gentle carotid artery stent placement. MATERIALS AND METHODS:We included patients who underwent carotid artery stent placement for extremely high-grade stenosis from January 2015 to March 2019. We defined extremely high-grade stenosis as carotid stenosis with conventional angiographic "slow flow" and a reduced MCA signal intensity on MRA. A reduced MCA signal intensity was defined as MCA with a relative signal intensity of ,0.9 in the ipsilateral compared with the contralateral MCA. We evaluated the stent diameter, CBF on SPECT, hyperperfusion syndrome, and intracranial hemorrhage. We defined hyperperfusion syndrome as a triad of ipsilateral headache, seizure, and hemiparesis.RESULTS: Twenty-eight of the 191 patients met our inclusion criteria. After carotid artery stent placement, their median minimal stent diameter was 2.9 mm, which expanded to 3.9 mm at 4 months. Neither cerebral hyperperfusion syndrome nor intracranial hemorrhage occurred. CONCLUSIONS:The gentle carotid artery stent placement strategy for intentional residual stent stenosis may prevent hyperperfusion syndrome in high-risk patients. Stents spontaneously dilated in 4 months.ABBREVIATIONS: AI ¼ asymmetric index; AVDO 2 ¼ arteriovenous difference of oxygen; CAS ¼ carotid artery stent placement; HI ¼ hemodynamic insufficiency; ex-HS ¼ extremely high-grade carotid artery stenosis; HPP ¼ hyperperfusion phenomenon; HPS ¼ hyperperfusion syndrome; ICH ¼ intracerebral hemorrhage; MLD ¼ minimal luminal diameter; OEF ¼ oxygen extraction fraction; PSV ¼ peak systolic velocity; rCBF ¼ regional CBF; SI ¼ signal intensity

Reduced magnetic resonance angiography signal intensity in the middle cerebral artery ipsilateral to severe carotid stenosis may be a practical index of high oxygen extraction fraction

“…Before positioning the temporary pacing catheter, we introduced a 4-Fr catheter (Cerulean, Medikit Co., Ltd.) into the dominant-side jugular bulb via transfemoral venous access and sampled blood with heparinized syringes (2.5 mL). We sampled blood in the carotid artery through the arterial guide catheter (Online Figure I ) [ 14 , 19 ]. We measured the arterial oxygen content and venous oxygen content with a blood gas analyzer and calculated the wb-OEF to estimate the risk of hyperperfusion syndrome after CAS [ 5 ].…”

“…However, a significant relationship exists between the PET hemodynamic parameters and arteriographic circulation pattern [ 13 ]. Angiographic “slow flow” in the middle cerebral artery (MCA) ipsilateral to hg-CS may be associated with a high OEF [ 14 , 15 ]. Post-CAS OEF decreased compared to pre-CAS OEF in patients with angiographic slow flow in the MCA distal to high-grade carotid stenosis [ 14 ].…”

“…Angiographic “slow flow” in the middle cerebral artery (MCA) ipsilateral to hg-CS may be associated with a high OEF [ 14 , 15 ]. Post-CAS OEF decreased compared to pre-CAS OEF in patients with angiographic slow flow in the MCA distal to high-grade carotid stenosis [ 14 ]. If MCA slow flow ipsilateral to severe carotid stenosis is associated with a reduced MCA relative signal intensity (rSI) on MR angiography (MRA), the reduced MCA rSI may be associated with a high OEF, and then may be a practical index of high OEF, which would be beneficial compared to the unusual and invasive catheter-based OEF measurement.…”

Gradual Expansion of a Stent to Prevent Periprocedural Complications after Carotid Artery Stenting for Vulnerable Severe Stenotic Lesions with Intraplaque Hemorrhages: A Retrospective Observational Study

“…A reduced MCA SI on MRA ipsilateral to severe carotid stenosis may be a feasible index to identify patients at high risk of hyperperfusion syndrome after CAS [11][12][13]. We measured the SI on the bilateral MCA M1 segments on MRA and calculated rSI according to a previously reported method [13].…”

“…We measured the SI on the bilateral MCA M1 segments on MRA and calculated rSI according to a previously reported method [13]. Extremely severe carotid stenosis (ex-CS) with probable high oxygen extraction fraction is defined as severe carotid stenosis of an MLD ≤ 1.06 mm combined with ipsilateral MCA rSI ≤ 0.89 [13], and patients with ex-CS are at high risk of hyperperfusion syndrome following CAS [11,13].…”