Optimal ultrasound criteria for defining the severity of vertebral artery in-stent restenosis

A novel angiographic classification for the endovascular recanalization of symptomatic nonacute extracranial vertebral artery occlusion

BACKGROUND

There remains major uncertainty regarding the optimal therapy for symptomatic nonacute extracranial vertebral artery occlusion (EVAO). Endovascular recanalization for EVAO is technically challenging, and limited data are available. This research aimed to report a multicenter clinical experience of endovascular recanalization for symptomatic nonacute EVAO and establish a novel angiographic classification.

METHODS

From June 2011 to December 2019, 50 symptomatic nonacute EVAO patients treated with endovascular recanalization in three regional referral stroke centers were retrospectively analyzed. All patients were categorized into four groups based on the angiographic classification. The rates of technical success, periprocedural complications, any stroke or death within 1 month, and follow-up data were assessed.

RESULTS

The rates of technical success, periprocedural complications, and any stroke or death within 1 month were 86.0% (43/50), 12.0% (6/50), and 4.0% (2/50), respectively. The recanalization rates gradually decreased from Type A to Type D (100%, 94.7%, 80%, and 63.6%, respectively; P=0.007). The EVAO patients in the Type A group with tapered stump and short-segment occlusions showed excellent recanalization effects, with 100% technical success rates and no complications. Conversely, the lowest recanalization rate of 63.6% (7/11) and the highest periprocedural complication rate of 27.3% (3/11) were observed for the Type D group.

CONCLUSIONS

Endovascular recanalization for symptomatic nonacute EVAO is technically feasible, especially Type A EVAO patients, which can provide an alternative treatment option for recurrent vertebrobasilar ischemia despite optimal medical therapy. The angiographic categorization established in this study is conducive to the selection of suitable patients prior to treatment decision.

Transcranial Color-Coded Sonography Criteria for Moderate and Severe Middle Cerebral Artery Stenosis

This study aimed to establish optimal criteria for evaluation of moderate (50%-69%) and severe (70%-99%) middle cerebral artery (MCA) stenosis with transcranial color-coded sonography (TCCS). A total of 375 cases provided 409 TCCS/digital subtraction angiography vessel pairs. Peak systolic velocity (PSV), end-diastolic velocity (EDV) and mean flow velocity (MFV) of the MCA were measured. The stenotic/distal MFV ratios (SDRs) were calculated. With digital subtraction angiography as a reference, for 50%-69% MCA stenosis, the optimal combined criteria were PSV ≥180 cm/s (sensitivity 95.7%, specificity 64.9% and overall accuracy 69.7%); EDV ≥75 cm/s (90.0%, 66.4% and 68.7%); MFV ≥110 cm/s (95.7%, 64.0% and 69.4%); and SDR ≥2.5 (88.6%, 71.3% and 76.3%). Criteria for 70%-99% MCA stenosis were PSV ≥240 cm/s (93.5%, 89.9% and 85.5%); EDV ≥100 cm/s (96.8%, 89.0% and 87.3%); MFV≥160 cm/s (91.9%, 92.8% and 92.2%); and SDR ≥4 (87.1%, 92.2% and 91.4%). Parameters of the MCA detected by TCCS, especially SDR, may increase accuracy in diagnosis of 50%-69% and 70%-99% MCA stenosis.

Validation and comparison of drug eluting stent to bare metal stent for restenosis rates following vertebral artery ostium stenting: A single-center real-world study

BACKGROUND AND PURPOSE

While drug-eluting stents (DES) have been widely applicated in coronary stenosis, uncertainty persists concerning the relative performance and clinical benefit in patients undergoing vertebral artery stenting when compared with a bare metal stent (BMS). We sought to compare in-stent restenosis (ISR) rates of DES and BMS in the treatment of vertebral artery ostium (VAO) stenosis.

MATERIALS AND METHODS

This study analyzed a single-center prospective cohort. Over 1.5-year period (January 2014-June 2015), 137 consecutive patients underwent VAO stenting involving deployment of 76 DES and 74 BMS. Patient demographics, comorbidities, stenosis severity, stent diameters and lengths, periprocedural complications, imaging and duplex ultrasonography follow-up and recurrent symptoms were assessed.

RESULTS

Technical success was achieved in all patients. Mean VAO stenosis at presentation were 82.4 ± 7.2% in the DES group and 83.3 ± 7.5% in the BMS group and were reduced to 12.5 ± 4.5% and 11.3 ± 4.0%. Mean stent diameter was 3.53 ± 0.40 mm in DES and 5.05 ± 0.40 mm in BMS (p < 0.0001). Mean follow-up was 12.3 months for DES and 11.7 months for BMS. The use of DES was associated with significant lower ISR rates compared with BMS (18.4% vs. 31.1%; OR = 2.628, p = 0.021). Recurrent symptoms rates were similar in DES vs. BMS (2.6% vs 2.7%, p = 0.680). Stent type and stent diameter were independent risk factors for ISR (P = 0.026).

CONCLUSION

Our results suggest superior efficacy of deploying DES for the treatment of VAO stenosis with lower ISR rates as compared to BMS, but do not support significant differences in periprocedural risk and recurrent symptoms rate.

Ultrasound Criteria for Assessment of Vertebral Artery Origins

BACKGROUND AND PURPOSE

We sought to validate ultrasound as a reliable means of assessing vessel stenosis of vertebral artery origins.

METHODS

We reviewed 1,135 patient charts with ultrasound of the posterior circulation performed in 2008-2015 in a single hospital. Inclusion criteria for native vessels consisted of ultrasound and digital subtraction angiography (DSA) performed within 3 months. Patients with indwelling stents were analyzed separately from native vessels. Using DSA as the gold standard, we determined sensitivity and specificity of ultrasound in detecting occlusion at vertebral artery origin. All patients with nonoccluded native vertebral artery origins were evaluated for degree of stenosis on DSA, and compared to mean flow velocity (MFV), peak systolic velocity (PSV), and end-diastolic velocity (EDV) on ultrasound.

RESULTS

Among 218 vertebral artery origins in 139 patients evaluated, ultrasound showed sensitivity of 85.7% (95% confidence interval (CI): 69.7-95.2%) for occlusion and specificity of 99.5% (95%CI: 96.9-99.9%). Among 126 arteries without occlusion, <50% stenosis had average MFV (39 ± 19 cm/s), 50-69% stenosis had average MFV (68 ± 35 cm/s), and severe (70-99%) stenosis had average MFV (120 ± 93 cm/s) (P < .001). MFV cutoff value of 44 cm/s corresponded to 77% sensitivity and 70% specificity to detect vertebral artery origin stenosis >50% (C-statistic: .81). PSV value of 97 cm/s corresponded with 72% sensitivity and 70% specificity to detect >50% stenosis (C-statistic: .77). MFV cutoff value of 60 cm/s corresponded with 70% sensitivity and 82% specificity to predict 70-99% stenosis (C-statistic: .83). PSV cutoff value of 110 cm/s corresponded with 80% sensitivity and 72% specificity to predict 70-99% stenosis (C-statistic: .84).

CONCLUSION

Ultrasound has good sensitivity and excellent specificity for detecting vertebral origin occlusion. Flow velocity can be used to screen for severe stenosis of vertebral artery at origin.

Arterial occlusions increase the risk of in-stent restenosis after vertebral artery ostium stenting

OBJECTIVE

The study was designed to investigate if vascular occlusion in the internal carotid artery (ICA) or the contralateral vertebral artery (VA) contribute to developing in-stent restenosis (ISR) in patients with vertebral artery ostium stenosis (VAOS).

METHODS

420 consecutive patients treated with VAOS stents (from a population of 8145 patients with VAOS) from January 2013 to December 2014 were analyzed in this retrospective study; 216 with drug eluted stents and 204 with bare metal stents. Based on pre-stent DSA findings, patients were divided into four groups: both carotid and vertebral arteries patent (PAT), ICA occlusion (ICA-OCC), contralateral VA occlusion (CVA-OCC), and combined occlusions (C-OCC). The incidence of ISR (stenosis >50%) was compared between groups using Cox regression analysis.

RESULTS

Of the 420 patients, the mean incidence of ISR was 36.4%, with a median 12 months of follow-up (IQR 3-12). Logistic regression analysis showed that drug eluting stent had less ISR than bare metal stent (OR=0.38, 95% CI 0.19 to 0.75, P=0.01). Cox regression analysis showed that CVA-OCC (HR=1.63, P=0.02) and C-OCC (HR=3.30, P=0.001) were risk factors for ISR but not ICA-OCC (P=0.31). In the CVA-OCC and C-OCC groups, in-stent peak systolic velocity (PSV) ≥140 cm/s, 1 day after successful stenting, was associated with subsequent development of ISR (OR=2.81, 95% CI 1.06 to 7.43, P=0.04).

CONCLUSION

Contralateral VA occlusion at the time of stenting increased the risk of ISR, especially if stent PSV on day 1 was >140 cm/s. Bare metal stents had more ISR than drug eluting stents.