Risk factors for silent new ischemic cerebral lesions following carotid artery stenting

Navigating complexity with low-crossing profile dual-layer micromesh carotid stent: implications for contemporary carotid artery stenting outcomes (ROADSAVER study insights)

BACKGROUND

The safety and efficacy of carotid artery stenting (CAS) can be affected by certain technical and anatomical factors. However, it is not known whether the use of a dual-layer micromesh stent (DLMS) with a low-crossing profile could reduce the risks associated with complex vascular anatomies during CAS.

METHODS

This study involved 1965 asymptomatic or symptomatic carotid artery stenosis patients who received the Roadsaver DLMS during CAS, as part of a prospective, multicenter observational ROADSAVER study, conducted from January 2018 to February 2021. The primary outcome was the 30-day rate of major adverse events (MAE; i.e. any death or stroke) after CAS. Procedural details and outcomes were compared between patients with complex anatomical features and those without.

RESULTS

One or more complex anatomical characteristics were identified in 1639 (83.4%) patents. Patients with complex anatomies were older and had a higher prevalence of arterial hypertension, cardiovascular disease, and prior stroke. Between patients with or without complex anatomical features, no significant differences were found either in procedural techniques, or in 30-day MAE (age-adjusted odds ratio (95% CI) for complexities vs. no complexities: 0.76 (0.35, 1.66); p=0.4905) and any stroke (age-adjusted odds ratio (95% CI) for complexities vs. no complexities: 0.89 (0.37, 2.17); p=0.8032) incidence. Furthermore, neither the presence of specific types of anatomic complexity nor their number (per patient) markedly influenced the 30-day MAE and any stroke incidence.

CONCLUSIONS

In this real-world cohort of patients undergoing CAS with the Roadsaver DLMS, no significant difference in the occurrence of 30-day MAE and any stroke was observed between patients with or without high-risk anatomical features.

Hematological predictors of silent new cerebral ischemic lesions in carotid artery stenting: A retrospective study

BACKGROUND

Silent new cerebral ischemic lesions (sNCIL) are a common complication of carotid artery stenting (CAS) that can lead to an increase in morbidity and mortality. We aimed to evaluate the impact of hematological parameters on sNCIL in patients undergoing CAS.

METHODS

We retrospectively evaluated 103 patients who underwent CAS, with a mean age of 70.5 ± 6.7 years, and 31 (20.1 %) of whom were female. Stents were placed for internal carotid artery revascularization. The presence of new hyperintense lesions on diffusion-weighted imaging (DWI) without neurological symptoms was considered as sNCIL in cases without apparent neurological findings. Patients were categorized into two groups based on DWI results: positive (29) and negative (74).

RESULTS

In the study population, sNCIL was observed in 29 patients (28.2 %). The DWI-positive group exhibited significantly higher Plateletcrit (PCT) levels, advanced age, and a lack of embolic protection device usage compared to the DWI-negative group. The Receiver Operating Characteristic (ROC) analysis identified a PCT value of 0.26 as the optimal threshold, detecting the development of sNCIL with a sensitivity of 75.9 % and specificity of 59.1 % (AUC: 0.700; 95 % CI: 0.594-0.806, p = 0.002).

CONCLUSION

To be determined by a simple blood parameter, PCT can predict the risk of sNCIL before CAS and holds clinical value in the treatment of patients with carotid artery stenosis.

Distal normal vessel diameter might be associated with silent brain infarcts after stenting for symptomatic carotid stenosis

BACKGROUND

Carotid artery stenting (CAS) has been the standard treatment for carotid stenosis because it is less invasive; however, the risk of periprocedural thromboembolism is high. We investigated the predictors for silent brain infarcts (SBIs), focusing on embolic protection in CAS.

METHODS

This study was single-center retrospective study, and we obtained baseline demographics and clinical, laboratory, and periprocedural variables of patients who underwent CAS. Also, methods used for embolic protection (no EPD, distal EPD, or proximal balloon guiding catheter) during CAS were obtained. Distal normal vessel diameter was defined as the diameter of cervical internal carotid artery where the artery wall becomes parallel. Diffusion-weighted imaging was performed before and after procedure to detect SBIs. The primary outcome was stented territory SBIs, and the secondary outcomes were any territories SBIs and stented territory SBIs in cases with EPD.

RESULTS

A total of 196 CAS procedures with mean age 69.1 ± 9.9 years were included. After CAS, stented territory SBIs occurred in 53 (27.0 %) cases and any territories SBIs in 60 (30.6 %) cases. Univariable analyses revealed that distal normal vessel diameter (odds ratio = 1.71, 95 % confidence interval = 1.20-2.43, P = 0.003) was associated with the occurrence of stented territory SBIs after CAS. After adjusting for potential variables, larger distal normal vessel diameter (1.61 [1.10-2.36], P = 0.014) increased the occurrence of SBIs after CAS. Consistent results were obtained when the outcome was any territories SBIs or stented territory SBIs in cases with EPD.

CONCLUSIONS

Distal normal vessel diameter was a predictor for the occurrence of SBI after CAS. The passable pore size of EPDs may vary depending on vessel diameter, and may impact the occurrence of SBIs.

Cadaver investigation of the usefulness of the transstyloid diaphragm approach for high-position plaque carotid endarterectomy

OBJECTIVES

Patients sometimes present with high cervical internal carotid artery (ICA) stenosis. This study demonstrates the usefulness of the transstyloid approach to expose the distal ICA by dissection of the styloid diaphragm covering the distal cervical ICA for carotid endarterectomy (CEA). In particular, the possible exposure length achieved by this approach was investigated using cadaveric heads.

METHODS

The procedure of the transstyloid diaphragm approach was confirmed in 10 cadaveric heads (20 sides). After the carotid triangle was opened, both the posterior belly of the digastric muscle (PBDM) and the stylohyoid muscle could be divided. Then, the carotid sheath was dissected, and the glossopharyngeal nerve was identified crossing over the distal ICA. The revealed length of the ICA was measured with or without dissection of both the PBDM and the stylohyoid muscle. The specimens were dissected under the surgical microscope.

RESULTS

The transstyloid diaphragm approach was achieved successfully in all specimens. The revealed lengths of the ICA with and without dissection of the styloid diaphragm were 53.7 ± 5.9 mm and 38.8 ± 2.9 mm (mean ± standard deviation), respectively. Therefore, the revealed length of the distal ICA was 14.9 ± 4.5 mm greater using the transstyloid diaphragm approach compared to the regular CEA approach.

CONCLUSIONS

More of the ICA can be revealed by dissection of both the PBDM and the stylohyoid muscle. The transstyloid diaphragm approach might be helpful to reveal the distal ICA in cases of high cervical ICA stenosis.

Silent brain infarcts after carotid or vertebrobasilar artery stenting

BACKGROUND AND PURPOSE

Stenting is an important treatment for preventing stroke. However, the effect of vertebrobasilar stenting (VBS) might be limited because of relatively high periprocedural risks. Silent brain infarcts (SBIs) are known as a predictor for future stroke. Because of anatomical differences, factors for SBIs might be different between carotid artery stenting (CAS) and VBS. We compared the characteristics of SBIs between VBS and CAS.

METHODS

We included patients who underwent elective VBS or CAS. Diffusion-weighted imaging was performed pre- and post-procedure to detect new SBIs. Clinical variables, occurrence of SBIs, and procedure-related factors were compared between CAS and VBS. Moreover, we investigated predictors of SBIs in each group separately.

RESULTS

Ninety-two (34.2%) out of 269 patients had SBIs. SBIs were more frequently observed in VBS (29 [56.6%] vs. 63 [28.9%], p<.001). The risk of SBIs outside the stent-inserted vascular territory was higher in VBS compared to CAS (14 [48.3%] vs. 8 [12.7%], p<.001). Larger-diameter stents (odds ratio: 1.28, 95% confidence interval: 1.06-1.54, p = .012) and prolonged procedure time (1.01, [1.00-1.03], p = .026) increased the risk of SBIs in CAS, whereas only age increased the risk of SBIs in VBS (1.08 [1.01-1.16], p = .036).

CONCLUSIONS

Compared to CAS, VBS was associated with longer procedure time, more residual stenosis, and more SBIs, especially outside the stent-inserted vascular territory. The risk of SBIs after CAS was associated with stent size and procedural difficulty. Only age was associated with SBIs in VBS. The pathomechanism of SBIs after VBS and CAS may be different.

Absence of the Anterior Communicating Artery on Selective MRA is Associated with New Ischemic Lesions on MRI after Carotid Revascularization

BACKGROUND AND PURPOSE

ICA-selective MRA using a pencil beam presaturation pulse can accurately visualize anterior communicating artery flow. We evaluated the impact of anterior communicating artery flow on the perioperative hemodynamic status and new ischemic lesions after carotid revascularization.

MATERIALS AND METHODS

Eighty-three patients with carotid artery stenosis were included. We assessed anterior communicating artery flow using ICA-selective MRA. The preoperative hemodynamic status was measured using SPECT. We also measured the change in regional cerebral oxygen saturation after temporary ICA occlusion. New ischemic lesions were evaluated by DWI on the day after treatment.

RESULTS

Anterior communicating artery flow was detected in 61 patients, but it was not detected in 22 patients. Preoperative cerebrovascular reactivity was significantly higher in patients with (versus without) anterior communicating artery flow with a mean peak systolic velocity of ≥200 cm/s (39.6% [SD, 23.8%] versus 25.2% [SD, 16.4%]; P = .030). The decrease in mean regional cerebral oxygen saturation was significantly greater in patients without (versus with) anterior communicating artery flow (8.5% [SD, 5.6%] versus 3.7% [SD, 3.8%]; P = .002). New ischemic lesions after the procedure were observed in 23 patients. The multivariate logistic regression analysis revealed that anterior communicating artery flow (OR, 0.07; 95% CI, 0.012-0.45; P = .005) was associated with new ischemic lesions.

CONCLUSIONS

The absence of anterior communicating artery flow influenced the perioperative hemodynamic status in patients with carotid stenosis and was associated with an increased incidence of new ischemic lesions after carotid revascularization.

Association of Aortic Arch Calcification on Chest X-ray with Procedural Thromboembolism after Mechanical Thrombectomy for Acute Ischemic Stroke

Background and Objective: Procedural thromboembolism after a mechanical thrombectomy (MT) for an acute ischemic stroke (AIS) has rarely been studied. It may occur from the artery-to-artery embolization of atherosclerotic plaque in the aortic arch. We investigated the relationship between aortic arch calcification (AoAC) on a chest X-ray and procedural thromboembolism on diffusion-weighted imaging (DWI) after an MT. Materials and Methods: From January 2017 to December 2020, 131 patients underwent DWI within two days following an MT for an AIS. Procedural thromboembolism was defined as new DWI-positive lesions in other territories from the occluded artery on DWI within two days after MT. Results: Procedural thromboembolism was observed in 30 (22.9%) patients. Procedural thromboembolism was associated with old age (72.3 ± 9.44 vs. 65.7 ± 12.8 years, p = 0.003), a longer procedural time (77.6 ± 37.6 vs. 60.1 ± 29.7 min, p = 0.024), and AoAC (calcification (73.3%) vs. no calcification (29.7%), p < 0.001). Multivariable logistic regression analysis showed that procedural thromboembolism was independently associated with AoAC (adjusted odds ratio (OR): 6.107, adjusted 95% confidence interval (CI): 2.374–15.705, p < 0.001) and a longer procedural time (adjusted OR: 1.015, adjusted 95% CI: 1.001–1.030, p = 0.031). Conclusions: Procedural thromboembolism after an MT for an AIS was related to AoAC on a chest X-ray and a longer procedural time. Our results suggest that although rapid recanalization is the most crucial goal of an MT for an AIS, the importance of the careful advance of the guiding catheter through the aortic arch should not be underestimated to reduce the risk of procedural thromboembolism, especially in patients with AoAC on a chest X-ray.

The effect of complex vascular anatomy on silent new ischemic cerebral lesions in carotid artery stenting procedures (from the COMPLEX-CAS Trial)

BACKGROUND

Carotid artery stenting is a minimally invasive, durable alternative treatment option, which is an alternative to the reference method, carotid endarterectomy, for patients with carotid artery stenosis; however, silent new ischemic cerebral lesions (SNICLs) after carotid artery stenting remain as a matter of concern. Hence, we aimed to assess the effect of complex vascular anatomy on silent new ischemic cerebral lesions in carotid artery stenting procedures.

METHODS

We prospectively evaluated 122 patients (mean age: 69.5 ± 7.1 years, male:83) who underwent carotid artery stenting for carotid artery revascularization. The patients having symptomatic transient ischemic attack or stroke after carotid artery stenting were excluded. The presence of a new hyperintense lesions on diffusion-weighted imaging without any neurological findings was considered as the SNICL. Patients were classified into two groups as DWI-positive and DWI-negative patients.

RESULTS

Among the study population, 32 patients (26.2%) had SNICLs. The DWI-positive group had a significantly higher common carotid artery (CCA)-internal carotid artery (ICA) angle, older age, more frequent history of stroke, a higher proportion of type III aortic arch, and longer fluoroscopy time than the DWI-negative group. High CCA-ICA angle was identified as one of the independent predictors of SNICL (OR (odds ratio) = 1.103 95%CI (confidence interval): (1.023-1.596); p = 0.034), and CCA-ICA angle higher than 34.5 degrees predicted SNICL with a sensitivity of 62.5% and a specificity of 62.2% (area under the curve: 0.680; 95% CI: 0.570 to 0.789; p = 0.003).

CONCLUSIONS

The higher CCA-ICA angle may predict pre-procedure SNICL risk in carotid artery stenting and may have clinical value in the management of patients with carotid artery stenosis.

The predictive value of CHADS2 score for subclinical cerebral ischemia after carotid artery stenting (from the PREVENT-CAS trial)

BACKGROUND

Carotid artery stenting (CAS) is being increasingly used as an alternative revascularization procedure to carotid endarterectomy; however, subclinical ischemic cerebral lesions after CAS remain as a matter of concern. Hence, we aimed to assess the clinical utility of the CHADS₂ score in predicting subclinical ischemic events after CAS.

METHODS

We prospectively evaluated 107 patients (mean age: 70.4 ± 6.6 years, male:77) who underwent CAS for carotid artery revascularization. The patients having symptomatic transient ischemic attack or stroke after CAS were excluded. The presence of new hyperintense lesion on diffusion-weighted imaging (DWI) without any neurological findings was considered as silent ischemia. Patients were classified into two groups as DWI-positive and DWI-negative patients.

RESULTS

Among study population, 28 patients (26.2%) had subclinical embolism. The DWI-positive group had a significantly higher CHADS2 scores, older age, more frequent history of stroke, higher proportion of type III aortic arch, and longer fluoroscopy time than the DWI-negative group. Increased CHADS₂ score was identified as one of the independent predictors of silent embolism (OR = 5.584; 95%CI: 1.516-20.566; p = .010), and CHADS₂ score higher than 2.5 predicted subclinical cerebral ischemia with a sensitivity of 72% and a specificity of 71% (AUC: 0.793; 95% CI: 0.696 - 0.890; p < .001).

CONCLUSIONS

CHADS₂ score was able to predict the risk of periprocedural subclinical ischemic events in CAS and might be of clinical value in the management of patients with carotid artery stenosis.

Factors Associated with Procedural Thromboembolisms after Mechanical Thrombectomy for Acute Ischemic Stroke

Background and objective: Procedural thromboembolisms after mechanical thrombectomy (MT) for acute ischemic stroke has rarely been studied. We retrospectively evaluated factors associated with procedural thromboembolisms after MT using diffusion-weight imaging (DWI) within 2 days of MT. Materials and Methods: From January 2018 to March 2020, 78 patients with acute ischemic stroke who underwent MT were evaluated using DWI. Procedural thromboembolisms were defined as new cerebral infarctions in other territories from the occluded artery on DWI after MT. Results: Procedural thromboembolisms were observed on DWI in 16 patients (20.5%). Procedural thromboembolisms were associated with old age (73.8 ± 8.18 vs. 66.8 ± 11.2 years, p = 0.021), intravenous (IV) thrombolysis (12 out of 16 (75.0%) vs. 25 out of 62 (40.3%), p = 0.023), heparinization (4 out of 16 (25.0%) vs. 37 out of 62 (59.7%), p = 0.023), and longer procedural time (90.9 ± 35.6 vs. 64.4 ± 33.0 min, p = 0.006). Multivariable logistic regression analysis revealed that procedural thromboembolisms were independently associated with procedural time (adjusted odds ratio (OR); 1.020, 95% confidence interval (CI); 1.002–1.039, p = 0.030) and IV thrombolysis (adjusted OR; 4.697, 95% CI; 1.223–18.042, p = 0.024). The cutoff value of procedural time for predicting procedural thromboembolisms was ≥71 min (area under the curve; 0.711, 95% CI; 0.570–0.851, p = 0.010). Conclusions: Procedural thromboembolisms after MT for acute ischemic stroke are significantly associated with longer procedural time and IV thrombolysis. This study suggests that patients with IV thrombolysis and longer procedural time (≥71 min) are at a higher risk of procedural thromboembolisms after MT for acute ischemic stroke.