Effects of plaque characteristics and artery hemodynamics on the residual stenosis after carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) has become an alternative strategy to carotid endarterectomy for carotid artery stenosis. Residual stenosis was an independent risk factor for restenosis, with the latter affecting the long-term outcomes of CAS. This multicenter study aimed to evaluate the echogenicity of plaques and hemodynamic alteration by color duplex ultrasound (CDU) examination and investigate their effects on the residual stenosis after CAS.

METHODS

From June 2018 to June 2020, 454 patients (386 males and 68 females) with a mean age of 67.2 ± 7.9 years, who underwent CAS from 11 advanced stroke centers in China were enrolled. One week before recanalization, CDU was used to evaluate the responsible plaques, including the morphology (regular or irregular), echogenicity of the plaques (iso-, hypo-, or hyperechoic) and calcification characteristics (without calcification, superficial calcification, inner calcification, and basal calcification). One week after CAS, the alteration of diameter and hemodynamic parameters were evaluated by CDU, and the occurrence and degree of residual stenosis were determined. In addition, magnetic resonance imaging was performed before and during the 30-day postprocedural period to identify new ischemic cerebral lesions.

RESULTS

The rate of composite complications, including cerebral hemorrhage, symptomatic new ischemic cerebral lesions, and death after CAS, was 1.54% (7/454 cases). The rate of residual stenosis after CAS was 16.3% (74/454 cases). After CAS, both the diameter and peak systolic velocity (PSV) improved in the preprocedural 50% to 69% and 70% to 99% stenosis groups (P < .05). Compared with the groups without residual stenosis and with <50% residual stenosis, the PSV of all three segments of stent in the 50% to 69% residual stenosis group were the highest, and the difference in the midsegment of stent PSV was the largest (P < .05). Logistic regression analysis showed that preprocedural severe (70% to 99%) stenosis (odds ratio [OR], 9.421; P = .032), hyperechoic plaques (OR, 3.060; P = .006) and plaques with basal calcification (OR, 1.885; P = .049) were independent risk factors for residual stenosis after CAS.

CONCLUSIONS

Patients with hyperechoic and calcified plaques of the carotid stenosis are at a high risk of residual stenosis after CAS. CDU is an optimal, simple and noninvasive imaging method to evaluate plaque echogenicity and hemodynamic alterations during the perioperative period of CAS, which can help surgeons to select the optimal strategies and prevent the occurrence of residual stenosis.

Incidence and Predictors of In-stent Re-Stenosis in the Superficial Femoral Artery: Evaluation of Long-Term Outcomes by Color Duplex Ultrasound

This study aimed to investigate the incidence and predictors of in-stent re-stenosis (ISR) for nitinol stents in the superficial femoral artery (SFA) by color duplex ultrasound (CDU). In total, 235 patients undergoing SFA stenting were included in the present study. The cumulative ISR rates at 3, 6, 12, 24 and 36 mo post-procedure were 5.4%, 24.0%, 49.0%, 61.5% and 71.5%, respectively. The markedly low peak systolic velocity of the popliteal artery (PSV2) post-operation was inversely correlated with the ISR. The threshold for ≥50% re-stenosis was PSV2 ≤ 63 cm/s with 86.6% sensitivity and 90.5% specificity. With regard to re-occlusion, the PSV2 was ≤40 cm/s with 98.1% sensitivity and 93.4% specificity. Cox regression analysis indicated that the cumulative stent length, diabetes, and pre-stent stenosis level were independent risk factors of ISR. In conclusion, the ISR incidence after SFA stenting is relatively high and CDU follow-up is a feasible method for evaluating ISR.