Abstract
Objective
Carotid artery stent (CAS) occlusion is a rare complication not well studied. We used a national dataset to assess real world CAS experience to determine the rate of stent occlusion. The purpose of this study was to: 1) Identify risk factors associated with CAS occlusion on long-term follow-up (LTFU) and 2) Determine the adjusted odds of death/transient ischemic attack (TIA)/stroke (CVA) in patients with occlusion.
Methods
The national VQI CAS dataset (2016–2021) comprised the sample. The primary endpoint was occlusion on LTFU (9–21 months post-operatively as defined by the VQI LTFU dataset) with secondary endpoint examining a composite of death/TIA/CVA. Descriptive analyses used chi-square and Wilcoxon tests for categorical and continuous variables respectively. Adjustment variables were selected a priori based on clinical expertise and univariate analyses. Multivariable logistic regression was used to model the odds of occlusion and the odds of death/TIA/CVA. Generalized estimating equations accounted for center level variation.
Results
During the study period, 109 occlusions occurred in 12,143 cases (0.9%). On univariate analyses, symptomatic indication, prior stroke, prior neck radiation, lesion calcification (>50%), stenosis (>80%), distal embolic protection device (compared to flow reversal), balloon size, >1 stent and current smoking at time of LTFU were predictive for occlusion. Age ≥ 65, coronary artery disease (CAD), elective status, preoperative statin, preoperative and discharge P2Y12 inhibitor, use of any protection device intraoperatively and protamine were protective. On multivariable analyses, age ≥ 65, CAD, elective status and P2Y12 inhibitor on discharge were protective for occlusion, while patients with prior radiation and those taking P2Y12 inhibitor on LTFU were at increased odds. The adjusted odds of death/TIA/CVA in patients with occlusion on LTFU was 6.05; 95% CI: 3.61–10.11, p<0.0001.
Conclusions
This study provides an in-depth analysis of predictors for CAS occlusion on LTFU. On univariate analyses, variables related to disease severity (urgency, degree of stenosis, nature of lesion) and intraoperative details (balloon diameter, > 1 stent) were predictive for occlusion. These variables were not statistically significant after risk adjustment. On multivariable analyses, prior neck radiation was strongly predictive of occlusion. Elective status, patient age ≥ 65, CAD, and P2Y12 inhibitor upon discharge (but not on LTFU) were protective for occlusion. Additionally, patients who developed occlusion had high odds for death/TIA/CVA. These findings provide important data to guide clinical decision-making for carotid disease management, particularly identifying high-risk features for CAS occlusion. Closer post-operative follow-up and aggressive risk factor modification in these patients may be merited.
Keywords: Cerebrovascular disease, carotid artery, carotid artery stent, radiation arteritis, atherosclerosis, stent occlusion
1. INTRODUCTION
Carotid endarterectomy (CEA) has been the standard approach for the operative management of symptomatic or high-grade asymptomatic carotid artery stenosis since the 1950s. Despite the efficacy of CEA, certain high-risk surgical patients have benefited from the option of carotid artery stenting (CAS) since the approval of transfemoral CAS in 2005 (1). That number has increased significantly since the introduction of trans-carotid artery stenting (TCAR). The complications of CAS include restenosis, TIA, CVA, myocardial infarction, and death (1–5). In addition, one might hypothesize that since CAS is often used in patients with difficult anatomic features and in redo surgery, they may be at higher risk of postoperative occlusion compared to CEA patients. Postoperative CEA occlusion has been reported between 0.05% and 0.8% (6, 7). Stent occlusion in CAS is a complication not well-described in the literature and merits further investigation. The purpose of this study was to identify risk factors associated with CAS (both transfemoral CAS and TCAR) occlusion on long term follow-up (LTFU) and determine the adjusted risk of death/transient ischemic attack (TIA)/stroke (CVA) in patients found to have stent occlusion.
2. METHODS
The National Vascular Quality Initiative (VQI) CAS dataset (2016–2021) was used for analyses. The West Virginia University Institutional Review Board approved the protocol (2201505533). Patients less than 18 years of age were excluded from the analysis as were patients with no follow-up or missing follow-up information.
The primary endpoint was examining predictors of stent occlusion on long-term follow-up (LTFU), which is defined as 9–21 months post-operatively by the VQI LTFU dataset. The secondary endpoint examined the odds of a composite of death/TIA/CVA for patients that had occlusion compared to those that did not while adjusting for various characteristics.
2.1. Statistical Analysis
Baseline characteristics were examined across occlusion status and summarized via chi-square and Wilcoxon tests for categorical and continuous variables, respectively. Multivariable logistic regression models were used to calculate adjusted odds of occlusion as well as modeling the odds of death/TIA/CVA using occlusion as the main predictor of interest. Adjustment variables were selected a priori based on clinical expertise and univariate analyses. Generalized estimating equations with an independent working correlation were used to account for center level variation. Single imputation based on the full conditional specification method was performed for missing data using all available variables from descriptive analyses as well as endpoints, however descriptive data was analyzed on non-imputed data. All statistical analyses were conducted using SAS v9.4 (SAS Institute: Cary, NC), with an alpha of 0.05.
3. RESULTS
During the study period, there were 109 occlusions out of 12,143 cases (0.9%). On univariable analyses (Table 1–6), patients with occlusion were more likely to be younger (66.1% vs 40.5%), have symptomatic stenosis (60.6% vs 47.2%), prior ipsilateral stroke (33.9% vs 22.9%), prior neck radiation (41.7% vs 17.6%), right-sided stenosis (9.1% vs 4.0%), lesion calcification that is protruding into lumen (5.3% vs 1.1%), and have 2 stents used (11.1% vs 6.1%). Occluded patients were less likely to have CAD (29.4% vs 46.7%), prior CAD/CABG/PCI (36.7% vs 50.7%), elective surgery (67.9% vs 86.4%), discharge to home (84.4% vs 93.3%), pre-operative antiplatelet drugs (67.0% vs 83.8%), pre-operative statin (78.9% vs 87.4%), protection device usage (86.1% vs 94.8%), TCAR (flow reversal) versus TFCAS (distal embolic protection device) (43.16% vs 56.84%), and protamine (41.4% vs 56.4%). Sex (p=0.7634) and ethnicity (0.1471) were not found to be statistically significant between the groups.
Table 1:
Preoperative Demographics
| Variable | Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | |
|---|---|---|---|---|---|
| Age (years) | 80+ | 2363 (19.46%) | 2350 (19.53%) | 13 (11.93%) | <0.0001 |
| 70–79 | 4795 (39.49%) | 4772 (39.65%) | 23 (21.1%) | ||
| 60–69 | 3611 (29.74%) | 3575 (29.71%) | 36 (33.03%) | ||
| 50–59 | 1180 (9.72%) | 1151 (9.56%) | 29 (26.61%) | ||
| 40–49 | 151 (1.24%) | 144 (1.2%) | 7 (6.42%) | ||
| age < 40 | 43 (0.35%) | 42 (0.35%) | 1 (0.92%) | ||
| BMI* (kg/m2) | ≥ 30 | 4249 (35.23%) | 4210 (35.22%) | 39 (36.11%) | 0.7576 |
| 25–29.9 | 4571 (37.9%) | 4534 (37.93%) | 37 (34.26%) | ||
| 18.5–24.9 | 3029 (25.11%) | 3000 (25.1%) | 29 (26.85%) | ||
| < 18.5 | 212 (1.76%) | 209 (1.75%) | 3 (2.78%) | ||
| Sex | Female | 4400 (36.23%) | 4359 (36.22%) | 41 (37.61%) | 0.7634 |
| Male | 7743 (63.77%) | 7675 (63.78%) | 68 (62.39%) | ||
| Race/ethnicity | Hispanic/Latinx | 349 (2.88%) | 347 (2.89%) | 2 (1.83%) | 0.1471 |
| Non-white non-Hispanic/Latinx | 968 (7.99%) | 954 (7.95%) | 14 (12.84%) | ||
| White non-Hispanic/Latinx | 10792 (89.12%) | 10699 (89.16%) | 93 (85.32%) | ||
| Smoking | Current | 2768 (22.82%) | 2735 (22.75%) | 33 (30.28%) | 0.1119 |
| Prior | 6175 (50.9%) | 6129 (50.98%) | 46 (42.2%) | ||
| Never | 3188 (26.28%) | 3158 (26.27%) | 30 (27.52%) | ||
| Hypertension | 10796 (89.03%) | 10704 (89.7%) | 92 (85.19%) | 0.1988 | |
| Diabetes | 4414 (36.37%) | 4377 (36.39%) | 37 (33.94%) | 0.5969 | |
| CAD † | 5642 (46.51%) | 5610 (46.66%) | 32 (29.36%) | 0.0003 | |
| Prior CAD/CABG‡/PCI§ | 6135 (50.52%) | 6095 (50.65%) | 40 (36.7%) | 0.0037 | |
| CHF [] | 1774 (14.62%) | 1759 (14.62%) | 15 (13.89%) | 0.8295 | |
| COPD || | 3094 (25.49%) | 3064 (25.47%) | 30 (27.52%) | 0.6251 | |
| Dialysis | 123 (1.01%) | 123 (1.02%) | 0 (0%) | 0.2888 | |
| Elective | 10464 (86.21%) | 10390 (86.37%) | 74 (67.89%) | <0.0001 | |
| Ambulatory | 132 (88%) | 129 (87.76%) | 3 (100%) | 0.5196 | |
| Living at home | 11987 (99.03%) | 11878 (99.02%) | 109 (100%) | 0.2981 | |
| Discharge home | 11316 (93.2%) | 11224 (93.28%) | 92 (84.4%) | 0.0002 | |
| Indication | Symptomatic | 5742 (47.29%) | 5676 (47.17%) | 66 (60.55%) | 0.0053 |
| Asymptomatic | 6401 (52.71%) | 6358 (52.83%) | 43 (39.45%) |
Body mass index,
coronary artery disease,
coronary artery bypass graft,
percutaneous coronary intervention,
congestive heart failure,
chronic obstructive pulmonary disease
Table 6:
Long-Term Follow-Up Characteristics
| Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | |||||
|---|---|---|---|---|---|---|---|---|
| Number | Percentage | Number | Percentage | Number | Percentage | |||
| Current smoker | 2100 | 17.34 | 2073 | 17.27 | 27 | 25 | 0.0346 | |
| Current living status | Homeless | 4 | 0.03 | 4 | 0.03 | 0 | 0 | 0.078 |
| Nursing home | 214 | 1.76 | 209 | 1.74 | 5 | 4.59 | ||
| Home | 11925 | 98.2 | 11821 | 98.23 | 104 | 95.41 | ||
| New ipsilateral TIA | 100 | 0.83 | 95 | 0.79 | 5 | 4.59 | <0.0001 | |
| New ipsilateral CVA | 123 | 1.02 | 108 | 0.9 | 15 | 13.89 | <0.0001 | |
| Composite event (Death, TIA*, or CVA†) | 503 | 4.14 | 481 | 4 | 22 | 20.18 | <0.0001 | |
| Follow-up aspirin | 10538 | 86.95 | 10443 | 86.95 | 95 | 87.16 | 0.9499 | |
| Follow-up antiplatelet agent | 8565 | 70.68 | 8483 | 70.64 | 82 | 75.23 | 0.2946 | |
| Follow-up statin | 10741 | 88.63 | 10647 | 88.65 | 94 | 86.24 | 0.4296 | |
| Follow-up chronic anticoagulant | 1833 | 15.3 | 1815 | 15.29 | 18 | 16.82 | 0.6602 | |
| Long-term carotid stent reintervention - endovascular | 147 | 1.21 | 140 | 1.16 | 7 | 6.42 | <0.0001 | |
| Long-term carotid stent reintervention - surgical | 81 | 0.67 | 80 | 0.67 | 1 | 0.92 | 0.7477 | |
transient ischemic attack,
cerebrovascular accident,
myocardial infarction,
electrocardiogram,
magnetic resonance angiogram,
computed tomography angiogram
Again, on univariable analyses, when looking at peri-operative complications we found that occluded patients were more likely to have ipsilateral TIA (2.8% vs 0.5%), ipsilateral stroke (6.4% vs 1.0%), contralateral stroke (6.4% vs 1.0%), access site complication (7.3% vs 3.1%), and access site pseudoaneurysm (1.8% vs 0.3%). Occluded patients were less likely to be discharged on antiplatelet drugs (88.1% vs 96.2%). Examining long term follow-up characteristics, we found that occluded patients were more likely to have had the composite event (death, TIA, or stroke) (20.2% vs 4.0%), have ipsilateral TIA (4.6% vs 0.8%), and new ipsilateral CVA (13.9% vs 0.9%).
On multivariable adjustment (Table 7) the following factors were associated with reduced odds of occlusion: patients aged 65 and older had 60% lower odds of occlusion than those under 65 (AOR: 0.4; 95% CI 0.26–0.61), CAD was associated with 40% lower odds of occlusion (AOR: 0.6; 95% CI 0.38–0.93), elective status had 54% lower odds of occlusion (AOR: 0.46; 95% CI 0.26–0.81), and P2Y12 inhibitor on discharge had 70% lower odds of occlusion (AOR: 0.3; 95% CI 0.14–0.64). Whereas patients with prior neck radiation had 3.5 times higher odds of occlusion (AOR: 3.47; 95% CI 2.11–5.72), and those taking P2Y12 inhibitor on LTFU had 74% higher odds of occlusion (AOR: 1.74; 95% CI 1.08–2.81). The adjusted odds of death/TIA/CVA in patients with occlusion on LTFU was 6 times higher than those without (AOR: 6.05; 95% CI 3.61–10.11).
Table 7:
Multivariable analysis demonstrating significant factors contributing to carotid stent occlusion.
| Variable | Adjusted OR (95% CI) | P-value | |
|---|---|---|---|
| Race/ethnicity | White non-Hispanic/Latinx | Ref. | 0.4485 |
| Non-white non-Hispanic/Latinx | 1.41 (0.77, 2.57) | ||
| Hispanic/Latinx | 0.69 (0.16, 2.93) | ||
| Indication | Asymptomatic stenosis | Ref. | 0.7521 |
| Symptomatic stenosis | 1.08 (0.66, 1.79) | ||
| Medication loading | None | Ref. | 0.3387 |
| Aspirin or P2YI2 inhibitor | 1.3 (0.85, 1.99) | ||
| Statin | 1.11 (0.42, 2.91) | ||
| Both | 0.7 (0.37, 1.33) | ||
| Distinct lesions treated | 1 | Ref. | 0.7164 |
| 2 | 0.78 (0.2, 3.04) | ||
| Lesion type | Atherosclerosis | Ref. | 0.1416 |
| Re-stenosis | 1.51 (0.92, 2.48) | ||
| Dissection, trauma, FMD*, other | 0.62 (0.19, 1.99) | ||
| Lesion location | Bifurcation | Ref. | 0.7033 |
| CCA† | 1.01 (0.46, 2.22) | ||
| ICA‡ | 0.84 (0.51, 1.36) | ||
| Protection device type | None | Ref. | 0.8953 |
| Distal embolic protection device | 0.9 (0.35, 2.3) | ||
| Flow reversal | 0.82 (0.32, 2.12) | ||
| Number of stents | 1 | Ref. | 0.3162 |
| 2 | 1.41 (0.72, 2.77) | ||
| Age 65 and older | 0.4 (0.26, 0.61) | <0.0001 | |
| Hypertension | 0.97 (0.55, 1.69) | 0.9085 | |
| CAD§ | 0.6 (0.38, 0.93) | 0.0221 | |
| Elective | 0.46 (0.26, 0.81) | 0.0069 | |
| Ipsilateral prior TIA[] | 1.02 (0.64, 1.62) | 0.9369 | |
| Pre-op aspirin | 1.55 (0.79, 3.07) | 0.2035 | |
| Pre-op P2Y12 inhibitor | 0.63 (0.35, 1.13) | 0.1191 | |
| Pre-op statin | 0.74 (0.39, 1.38) | 0.3392 | |
| Pre-op anticoagulant | 0.8 (0.31, 2.07) | 0.6447 | |
| Prior neck radiation | 3.47 (2.11, 5.72) | <0.0001 | |
| Lesion stenosis ≥80% | 1.62 (0.95, 2.78) | 0.0759 | |
| Pre-dilate | 1.3 (0.76, 2.2) | 0.3407 | |
| Post-dilate | 0.66 (0.43, 1.01) | 0.0559 | |
| Protamine | 0.83 (0.54, 1.29) | 0.406 | |
| Antiplatelet IIb/IIIa inhibitor treatment | 1.47 (0.71, 3.04) | 0.2987 | |
| Postoperative vasopressors for hypotension | 1.22 (0.73, 2.03) | 0.4563 | |
| Discharged aspirin | 0.77 (0.33, 1.83) | 0.5601 | |
| Discharged P2Y12 inhibitor | 0.3 (0.14, 0.64) | 0.0017 | |
| Discharged statin | 1.55 (0.54, 4.46) | 0.4144 | |
| Discharged anticoagulant | 0.63 (0.21, 1.84) | 0.3963 | |
| Current smoking at follow-up | 1.41 (0.92, 2.17) | 0.1181 | |
| ASA at follow-up | 1.06 (0.54, 2.1) | 0.8562 | |
| P2Y12 inhibitor at follow-up | 1.74 (1.08, 2.81) | 0.0236 | |
| Statin at follow-up | 0.84 (0.4, 1.75) | 0.6456 | |
| Anticoagulant at follow-up | 2.02 (0.82, 4.99) | 0.1289 |
fibromuscular dysplasia,
common carotid artery,
internal carotid artery,
coronary artery disease,
transient ischemic attack
4. DISCUSSION
This study used the VQI CAS dataset to provide an in-depth analysis on prevalence and predictors of carotid stent occlusion on LTFU as well as the odds of death/TIA/CVA in patients with occlusion. This study represents the largest analysis of stent occlusions in patients undergoing CAS. On univariable analyses, variables related to disease severity (urgency, degree of stenosis, nature of lesion) and intraoperative details (balloon diameter, > 1 stent) had increased odds of occlusion (Tables 1–6). These were not found to be statistically significant after multivariable analysis (Table 7). On multivariable analyses, elective status, patient age ≥ 65, coronary artery disease (CAD), and P2Y12 inhibitor upon discharge lowered odds of occlusion. Prior neck radiation increased odds of occlusion (OR 3.47; 95% CI: 2.11–5.72, p<.0001) (Table 7). Interestingly, the use of P2Y12 inhibitor on LTFU also increased odds of occlusion, despite lowering these odds in the immediate discharge setting. Patients who developed occlusion had increased odds of death, TIA, and CVA (OR 6.05; 95% CI: 3.61–10.11, p<.0001). Furthermore, there was no difference in rate of occlusion between TCAR and TFCAS on multivariable analysis (Table 7).
In this study, age > 65 was a protective factor. This is interesting, as age has been found to have conflicting outcomes in carotid stenting. Bonati et al reported that patients older than 70 had a twofold increase in 120-day risk of stroke or death with TFCAS compared to CEA (8). However, much of the hypothesized risk for carotid stenting in patients of advance age is related to embolization from calcified aortic arches and studies have not specifically focused on stent occlusion. Smaller, single-institution studies demonstrated no increased risk of in-stent restenosis, thrombosis, or occlusion with increasing age (9, 10). In general, there is a potential for selection bias in older populations, with patients being selected to undergo a less invasive procedure, such as CAS (11). As such, older patients that have less favorable anatomy may still get a CAS as a result. Despite this possibility, we found that increased age remained a protective factor on multivariable analysis. Additional research in this area is warranted to better understand this finding.
Another protective factor for odds of occlusion was elective status. This finding is consistent with the literature. Studies have shown elective CAS has better overall outcomes when compared to emergent cases, similar to outcomes of CEA (OR 2.19, 95% CI 1.46–3.26, p < .001) (12, 13). Faateh et al revealed that emergent patients are also less likely to be on optimal medical therapy, which could explain our findings even further (12). Ultimately, our data suggests that patients who undergo CAS in the non-elective setting might benefit from an additional focus on optimizing maximum medical therapy upon discharge.
Another notable finding in this study was the association between a history of neck radiation (XRT) and increased odds of occlusion (OR 3.47, 95% CI 2.11–5.72, p < 0.0001). Radiation of the carotid arteries has been associated with increased rates of atherosclerosis in mice models with increased resistance to both atorvastatin and clopidogrel (14). Restenosis post-CAS in XRT patients has been widely debated; few studies directly discuss occlusion rates, and no formal definition has been determined. A significantly increased risk of restenosis (defined as >50%) in patients with prior XRT has been seen in studies with small patient populations (43% vs 13%) (15.8% vs 1.9%) (15, 16). One small study found that 8.6% of patients with prior XRT progressed to occlusion while no patients without XRT experienced stent occlusion (15). In a much larger study using the VQI dataset, Minc et al. found no difference in restenosis and reintervention rate in patients who underwent CAS for RT-related disease and atherosclerotic disease, but an overall increase in mortality for RT patients (17). In that study however, restenosis was defined as either 50–69%, or >70%, and included the occlusion patients in the >70% cohort (this was due to occlusion rates being too small to evaluate on their own in that model and because it was important to keep those patients in the sample for evaluating reintervention). This is an excellent example of how large dataset research is highly dependent on the focus of the analysis. Our results suggest that prior XRT is a significant risk factor for stent occlusion on LTFU, but with a low overall occlusion rate of 0.9%, it still represents a safe procedure for patients with carotid artery disease with a history of neck radiation. It is our opinion that with this low overall occlusion rate, CAS should still be offered preferentially to these difficult patients with closer post-procedure surveillance as part of the informed consent discussion.
Finally, this study demonstrates a paradoxical finding on the use of P2Y12 inhibitors and stent occlusion. Upon discharge, patients who received P2Y12 inhibitors were found to have a decreased odds of occlusion (OR 0.3, 95% CI 0.14–0.64, p = 0.0017), whereas patients continuing P2Y12 inhibitors on LTFU had increased odds of occlusion (OR 1.74, 95% CI 1.04–2.81, p = 0.0236). SVS guidelines recommend dual antiplatelet therapy (DAPT) be implemented for 1 month after CAS, preferably with clopidogrel due to decreased side effects, followed by aspirin indefinitely (18). In this study, patients with P2Y12 inhibitors on LTFU would have been on them for at least 9 months and may represent a group that clinicians felt were high risk, and therefore were kept on a P2Y12 inhibitor for longer than the recommended 1 month. Therefore, being on DAPT at the point of LTFU may be a marker for patients who were already at risk for occlusion due to clinical or technical features and the judgement of the surgeon. Despite this possibility, we found that increased age remained a protective factor on multivariable analysis. When counseling a patient on choice of approach, consideration of perioperative stroke risk and stent occlusion need to be weighed. Additional research in this area is warranted to better understand this finding as to better guide patient care.
This study is the largest study to identify predictors and rates for CAS occlusion, however there are limitations. First, the study is a retrospective analysis derived from the VQI database, thus variables not in the database were unable to be obtained. Second, there is no 30-day data reported widely in the VQI dataset, which limits our ability to understand when occlusions may have occurred and what other issues occurred in the short term. Furthermore, long-term follow-up was defined as 9–21 months postoperatively by the VQI, preventing us from assessing any patient that may have undergone complications after 21 months with the currently available data. Despite these limitations, our study provides important insight into a rare complication that would be difficult to assess without a large dataset.
5. CONCLUSIONS
This study identified the prevalence of, and predictors for CAS occlusion on LTFU. Overall, the CAS occlusion rate was found to be 0.9%. Risks factors predictive of stent occlusion were prior neck radiation and long-term use of P2Y12 inhibitors. Factors protective from occlusion were elective status, patient age ≥ 65, coronary artery disease (CAD), and P2Y12 inhibitor upon discharge. Our findings remain consistent with the current literature regarding odds of death/TIA/CVA in patients with stent occlusion (OR 6.05; 95% CI: 3.61–10.11, p<.0001). Our study provides the first in-depth analysis of factors associated with carotid stent occlusion, which can guide patient selection, shared decision making, surveillance and follow-up planning.
Supplementary Material
Table 2:
Pre-Procedure History
| Variable | Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | |
|---|---|---|---|---|---|
| Pre-procedure antiplatelet | 10153 (83.67%) | 10080 (83.82%) | 73 (66.97%) | <0.0001 | |
| Pre-procedure statin | 10596 (87.29%) | 10510 (87.36%) | 86 (78.90%) | 0.0083 | |
| Prior neck radiation | 1032 (17.81%) | 1007 (17.56%) | 25 (41.67%) | <0.0001 | |
| Prior ipsilateral CEA* | 1877 (32.40%) | 1860 (32.44%) | 17 (28.33%) | 0.4986 | |
| Lesion calcification (percentage) | Protruding into lumen | 80 (1.15%) | 77 (1.11%) | 3 (5.26%) | 0.0188 |
| 100% circumference | 106 (1.52%) | 104 (1.50%) | 2 (3.51%) | ||
| 51–99% circumference | 2328 (33.39%) | 2311 (33.42%) | 17 (29.82%) | ||
| 26–50% circumference | 1229 (17.63%) | 1224 (17.70%) | 5 (8.77%) | ||
| < 25% circumference | 1330 (19.07%) | 1319 (19.07%) | 11 (19.30%) | ||
| None | 1900 (27.25%) | 1881 (27.20%) | 19 (33.33%) | ||
| Medication loading | Both | 2292 (19.10%). | 2278 (19.15%) | 14 (12.96%) | 0.189 |
| Statin | 353 (2.94%) | 349 (2.93%) | 4 (3.70%) | ||
| ASA or P2YI2 antagonist | 2425 (20.20%) | 2396 (20.14%) | 29 (26.85%) | ||
| None | 6932 (57.76%) | 6871 (57.77%) | 61 (56.48%) | ||
carotid endarterectomy
Table 3:
Operative Details
| Variable | Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | ||||
|---|---|---|---|---|---|---|---|---|
| Number | Percentage | Number | Percentage | Number | Percentage | |||
| Distinct lesions treated | 2 | 214 | 1.76 | 212 | 1.76 | 2 | 1.83 | 0.9554 |
| 1 | 11913 | 98.24 | 11806 | 98.24 | 107 | 98.17 | ||
| Lesion type | Dissection, trauma, FMD*, other | 297 | 2.46 | 292 | 2.44 | 5 | 4.72 | 0.2237 |
| Re-stenosis | 2072 | 17.14 | 2051 | 17.11 | 21 | 19.81 | ||
| Atherosclerosis | 9722 | 80.41 | 9642 | 80.45 | 80 | 75.47 | ||
| Lesion location | ICA† | 8632 | 71.44 | 8560 | 71.48 | 72 | 66.67 | 0.2462 |
| CCA‡ | 1036 | 8.57 | 1022 | 8.53 | 14 | 12.96 | ||
| Bifurcation | 2415 | 19.99 | 2393 | 19.98 | 22 | 20.37 | ||
| Occluded | 24 | 0.21 | 22 | 0.19 | 2 | 1.98 | ||
| Lesion stenosis | 80–99% | 9153 | 79.67 | 9070 | 79.65 | 83 | 82.18 | 0.001 |
| 70–79% | 1601 | 13.94 | 1592 | 13.98 | 9 | 8.91 | ||
| 50–69% | 614 | 5.34 | 607 | 5.33 | 7 | 6.93 | ||
| 0–49% | 96 | 0.84 | 96 | 0.84 | 0 | 0 | ||
| Technical failure | 19 | 0.16 | 18 | 0.15 | 1 | 0.92 | 0.0435 | |
| Number of stents | 2 | 743 | 6.15 | 731 | 6.1 | 12 | 11.11 | 0.0311 |
| 1 | 11341 | 93.85 | 11245 | 93.9 | 96 | 88.89 | ||
| Pre-dilate | 7613 | 76.52 | 7555 | 76.54 | 58 | 74.36 | 0.6512 | |
| Post-dilate | 6513 | 54.23 | 6464 | 54.31 | 49 | 45.37 | 0.0633 | |
| Protection device type | Flow reversal | 6639 | 57.78 | 6598 | 57.9 | 41 | 43.16 | 0.0038 |
| Distal embolic protection device | 4851 | 42.22 | 4797 | 42.1 | 54 | 56.84 | ||
| Protamine | 6426 | 56.27 | 6385 | 56.4 | 41 | 41.41 | 0.0028 | |
| Anticoagulant | Other | 14 | 0.12 | 13 | 0.11 | 1 | 0.94 | 0.1241 |
| Argatroban | 7 | 0.06 | 7 | 0.06 | 0 | 0 | ||
| Bilvalirudin | 413 | 3.43 | 409 | 3.42 | 4 | 3.77 | ||
| Heparin | 11417 | 94.68 | 11319 | 94.7 | 98 | 92.45 | ||
| None | 207 | 1.72 | 204 | 1.71 | 3 | 2.83 | ||
Fibromuscular dysplasia,
internal carotid artery,
common carotid artery
Table 4:
Perioperative Complications
| Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | ||||||
|---|---|---|---|---|---|---|---|---|---|
| Number | Percentage | Number | Percentage | Number | Percentage | ||||
| Postop MACE* | 229 | 1.89 | 229 | 1.9 | 0 | 0 | 0.1459 | ||
| Ipsilateral TIA† (retinal/cortical) | 65 | 0.54 | 62 | 0.52 | 3 | 2.75 | 0.0015 | ||
| Ipsilateral stroke (retinal/cortical) | 125 | 1.03 | 118 | 0.98 | 7 | 6.42 | <0.0001 | ||
| Contralateral TIA (retinal/cortical) | 16 | 0.13 | 16 | 0.13 | 0 | 0 | 0.7027 | ||
| Contralateral stroke (retinal/cortical) | 125 | 1.03 | 118 | 0.98 | 7 | 6.42 | <0.0001 | ||
| Ipsilateral stroke treatment | Intracranial catheter based | 10 | 8.2 | 10 | 8.7 | 0 | 0 | 0.5509 | |
| Systemiclysis | 7 | 5.74 | 7 | 6.09 | 0 | 0 | |||
| Medical | 105 | 86.07 | 98 | 85.22 | 7 | 100 | |||
| Contralateral stroke treatment | Intracranial catheter based | 10 | 8.2 | 10 | 8.7 | 0 | 0 | 0.5509 | |
| Systemiclysis | 7 | 5.74 | 7 | 6.09 | 0 | 0 | |||
| Access site complication | 379 | 3.12 | 371 | 3.08 | 8 | 7.34 | 0.011 | ||
| Hematoma/bleeding | 307 | 2.53 | 302 | 2.51 | 5 | 4.59 | 0.1692 | ||
| Stenosis/occlusion | 27 | 0.22 | 26 | 0.22 | 1 | 0.92 | 0.1218 | ||
| Infection | 6 | 0.05 | 6 | 0.05 | 0 | 0 | 0.8156 | ||
| Pseudoaneurysm | 36 | 0.3 | 34 | 0.28 | 2 | 1.83 | 0.003 | ||
| AV‡ fistula | 2 | 0.02 | 2 | 0.02 | 0 | 0 | 0.8929 | ||
| Death | 0 | 0 | 0 | 0 | 0 | 0 | . | ||
major adverse cardiac event,
transient ischemic attack,
arteriovenous
Table 5:
Discharge Medications
| Overall (n=12,143) | No Occlusion (n=12,034) | Occlusion (n=109) | P-value | ||||
|---|---|---|---|---|---|---|---|
| Number | Percentage | Number | Percentage | Number | Percentage | ||
| Post-procedure aspirin | 11230 | 92.52 | 11130 | 92.53 | 100 | 91.74 | 0.757 |
| Post-procedure antiplatelet agent | 11672 | 96.15 | 11576 | 96.23 | 96 | 88.07 | <0.0001 |
| Post-procedure chronic anticoagulant | 1568 | 12.92 | 1555 | 12.93 | 13 | 11.93 | 0.7551 |
Highlights:
Radiation has been identified as a factor driving carotid stent occlusion
The rate of carotid artery stent occlusion is low, approximately 0.9%
Carotid stents remain a safe option for patients with history of neck radiation
Funding statement:
This work was supported by the National Institute of General Medical Sciences (5U54GM104942) and the National Institute of Diabetes and Digestive and Kidney Diseases (K23DK128569).
Footnotes
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Conflicts of Interest/Disclosure Statement: The authors have no conflicts of interest to disclose.
REFERENCES
- 1.Mantese VA, Timaran CH, Chiu D, Begg RJ, Brott TG. The Carotid Revascularization Endarterectomy versus Stenting Trial (CREST): stenting versus carotid endarterectomy for carotid disease. Stroke. 2010;41(10 Suppl):S31–4. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 2.Liang P, Soden P, Wyers MC, Malas MB, Nolan BW, Wang GJ, et al. The role of transfemoral carotid artery stenting with proximal balloon occlusion embolic protection in the contemporary endovascular management of carotid artery stenosis. J Vasc Surg. 2020;72(5):1701–10. [DOI] [PubMed] [Google Scholar]
- 3.Müller MD, Gregson J, McCabe DJH, Nederkoorn PJ, van der Worp HB, de Borst GJ, et al. Stent Design, Restenosis and Recurrent Stroke After Carotid Artery Stenting in the International Carotid Stenting Study. Stroke. 2019;50(11):3013–20. [DOI] [PubMed] [Google Scholar]
- 4.Schneider PA, Levy E, Bacharach JM, Metzger DC, Randall B, Garcia A, et al. A First-in-Human Evaluation of a Novel Mesh-Covered Stent for Treatment of Carotid Stenosis in Patients at High Risk for Endarterectomy: 30-Day Results of the SCAFFOLD Trial. JACC Cardiovasc Interv. 2018;11(23):2396–404. [DOI] [PubMed] [Google Scholar]
- 5.Jiao LQ, Song G, Li SM, Miao ZR, Zhu FS, Ji XM, et al. Thirty-day outcome of carotid artery stenting in Chinese patients: a single-center experience. Chin Med J (Engl). 2013;126(20):3915–20. [PubMed] [Google Scholar]
- 6.Yunoki M, Suzuki K, Uneda A, Hirashita K, Yoshino K. Acute internal carotid artery occlusion after carotid endarterectomy. Interdisciplinary Neurosurgery. 2016;5:54–7. [Google Scholar]
- 7.Murray NM, Wolman DN, Marks M, Dodd R, Do HM, Lee JT, et al. Endovascular Treatment of Acute Carotid Stent Occlusion: Aspiration Thrombectomy and Angioplasty. Cureus. 2020;12(5):e7997. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 8.Bonati LH, Dobson J, Algra A, Branchereau A, Chatellier G, Fraedrich G, et al. Short-term outcome after stenting versus endarterectomy for symptomatic carotid stenosis: a preplanned meta-analysis of individual patient data. Lancet. 2010;376(9746):1062–73. [DOI] [PubMed] [Google Scholar]
- 9.Meng R, Mi X, Sun D. Risk Factors for Recurrent Carotid-Artery Stenosis Following Stenting Treatment. Med Sci Monit. 2019;25:2429–34. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 10.Wen L, Wang S, Liu L, Chen L, Geng J, Kuang L, et al. The Long-Term Efficacy and Safety of Carotid Artery Stenting among the Elderly: A Single-Center Study in China. Behav Neurol. 2018;2018:4707104. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 11.Mehta A, Patel PB, Bajakian D, Schutzer R, Morrissey N, Malas M, et al. Transcarotid artery revascularization versus carotid endarterectomy and transfemoral stenting in octogenarians. J Vasc Surg. 2021;74(5):1602–8. [DOI] [PubMed] [Google Scholar]
- 12.Faateh M, Dakour-Aridi H, Kuo PL, Locham S, Rizwan M, Malas MB. Risk of emergent carotid endarterectomy varies by type of presenting symptoms. J Vasc Surg. 2019;70(1):130–7.e1. [DOI] [PubMed] [Google Scholar]
- 13.Milgrom D, Hajibandeh S, Antoniou SA, Torella F, Antoniou GA. Editor’s Choice - Systematic Review and Meta-Analysis of Very Urgent Carotid Intervention for Symptomatic Carotid Disease. Eur J Vasc Endovasc Surg. 2018;56(5):622–31. [DOI] [PubMed] [Google Scholar]
- 14.Hoving S, Heeneman S, Gijbels MJ, te Poele JA, Pol JF, Gabriels K, et al. Anti-inflammatory and anti-thrombotic intervention strategies using atorvastatin, clopidogrel and knock-down of CD40L do not modify radiation-induced atherosclerosis in ApoE null mice. Radiother Oncol. 2011;101(1):100–8. [DOI] [PubMed] [Google Scholar]
- 15.Protack CD, Bakken AM, Saad WE, Illig KA, Waldman DL, Davies MG. Radiation arteritis: a contraindication to carotid stenting? J Vasc Surg. 2007;45(1):110–7. [DOI] [PubMed] [Google Scholar]
- 16.Huang TL, Hsu HC, Chen HC, Lin HC, Chien CY, Fang FM, et al. Long-term effects on carotid intima-media thickness after radiotherapy in patients with nasopharyngeal carcinoma. Radiat Oncol. 2013;8:261. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 17.Minc SD, Thibault D, Marone L. Outcomes of carotid artery stenting in patients with radiation arteritis compared with those with atherosclerotic disease. J Vasc Surg. 2022;75(4):1286–92. [DOI] [PMC free article] [PubMed] [Google Scholar]
- 18.Ricotta JJ, Aburahma A, Ascher E, Eskandari M, Faries P, Lal BK. Updated Society for Vascular Surgery guidelines for management of extracranial carotid disease. J Vasc Surg. 2011;54(3):e1–31. [DOI] [PubMed] [Google Scholar]
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