Long-term outcomes after carotid artery stenting of patients with prior neck irradiation or surgery

Evaluating postoperative outcomes in patients with hostile neck anatomy undergoing transcarotid artery revascularization versus transfemoral carotid artery stenting

BACKGROUND

Carotid endarterectomy is relatively contraindicated in patients with a hostile neck anatomy who were historically revascularized with transfemoral carotid artery stenting (TFCAS). As transcarotid artery revascularization (TCAR) has progressively replaced TFCAS, evidence pertaining to hostile neck anatomy and TCAR is necessary to establish its safety and feasibility in this subgroup of patients. Therefore, we analyzed the impact of a hostile neck anatomy on outcomes in patients undergoing TCAR and further compared them with those undergoing TFCAS to establish recommendations for standard of care.

METHODS

All patients undergoing TCAR and TFCAS from November 2016 to June 2021 in the Vascular Quality Initiative database were included. Patients were characterized into two groups based on the neck anatomy. Hostile neck anatomy was defined as a history of neck radiation or prior neck surgery including prior carotid endarterectomy or radical neck dissection. Primary outcomes included technical failure, access site complications (hematoma, stenosis, infection, pseudoaneurysm and arteriovenous fistula), and stroke or death. Secondary outcomes included stroke, transient ischemic attack (TIA), myocardial infarction (MI), death, and a composite end point of stroke or TIA. Patients with nonatherosclerotic or multiple lesions were excluded from the analysis. Primary analysis was performed with all patients undergoing TCAR and outcomes between patients with hostile and nonhostile neck anatomy were compared. Further analysis included a comparison of patients with a hostile neck anatomy undergoing TCAR and TFCAS. Univariable and multivariable logistic regression was used to assess impact of hostile neck anatomy on postoperative outcomes. Results were adjusted for relevant potential confounders including age, gender, race, degree of stenosis, symptomatic status, comorbidities, preoperative medications, anesthesia type, and protamine use.

RESULTS

Among the 19,859 patients who underwent TCAR during the study period, 3636 (18.3%) had a hostile neck anatomy. On univariate analysis, both groups had comparable outcomes except for higher rates of stroke or death in patients with hostile neck anatomy. After adjusting for potential confounders, there were no differences in technical failure (adjusted odds ratio [aOR], 1.14; 95% confidence interval [CI], 0.59-2.21; P = .699), stroke (aOR, 0.86; 95% CI, 0.58-1.28; P = .464), death (aOR, 0.82; 95% CI, 0.39-1.71; P = .598), and MI (aOR, 1.18; 95% CI, 0.71-1.97; P = .518). However, patients with hostile neck were at a 30% increased risk of access site complications (aOR, 1.30; 95% CI, 1.0-1.6; P = .023). Further adjusted analysis comparing the outcomes in TFCAS and TCAR among patients with hostile neck anatomy showed an almost four-fold increase in risk of death (aOR, 3.77; 95% CI, 1.49-9.53; P = .005) and technical failure (aOR, 3.69; 95% CI, 1.82-7.47; P < .001) among patients undergoing treatment with TFCAS.

CONCLUSIONS

Patients with a hostile neck anatomy undergoing TCAR experienced an increased risk of access site complications; however, the risk for technical failure and postoperative stroke/death, stroke, TIA, MI, or death was similar among both groups. TFCAS was associated with significant increase in the risk of death and technical failure compared with TCAR in this group of patients. These results confirm that TCAR should be the preferred minimally invasive revascularization procedure for patients with hostile neck anatomy.

Plaque Protrusion in a Patient with Left Common Carotid Artery Stenting after Radiation Therapy: A Case Report

Objective

We report a case of additional carotid artery stenting (CAS) for plaque protrusion occurring after initial CAS for radiation-induced common carotid artery (CCA) stenosis.

Case Presentation

A 69-year-old man with a history of radiotherapy for laryngeal cancer presented to our hospital with sudden-onset right hemiparesis. Since vulnerable plaque of the left CCA was considered the embolic source for ischemic stroke, CAS was performed for left CCA stenosis. No perioperative complications were observed and the patient was discharged with a modified Rankin Scale score of 0. However, 1 month after CAS, cerebral embolism recurred. As protruding plaque was found on CTA, additional endovascular treatment was performed with intravascular ultrasonography. He was discharged without complications and showed a good outcome at 3 months.

Conclusion

In CCA stenosis after radiotherapy, accelerated arteriosclerosis may cause drug-resistant cerebral embolism and plaque protrusion after CAS, making determination of the treatment strategy difficult. Appropriate treatment options need to be based on individual underlying diseases and plaque instability.

Late Outcomes of Carotid Artery Stenting for Radiation Therapy-Induced Carotid Stenosis

PURPOSE

Carotid artery stenting (CAS) appears as a promising alternative treatment to carotid endarterectomy for radiation therapy (RT)-induced carotid stenosis. However, this is based on a poor level of evidence studies (small sample size, primarily single institution reports, few long-term data). The purpose of this study was to report the long-term outcomes of a multicentric series of CAS for RT-induced stenosis.

METHODS

All CAS for RT-induced stenosis performed in 11 French academic institutions from 2005 to 2017 were collected in this retrospective study. Patient demographics, clinical risk factors, elapsed time from RT, clinical presentation and imaging parameters of carotid stenosis were preoperatively gathered. Long-term outcomes were determined by clinical follow-up and duplex ultrasound. The primary endpoint was the occurrence of cerebrovascular events during follow-up. Secondary endpoints included perioperative morbidity and mortality rate, long-term mortality rate, primary patency, and target lesion revascularization.

RESULTS

One hundred and twenty-one CAS procedures were performed in 112 patients. The mean interval between irradiation and CAS was 15 ± 12 years. In 31.4% of cases, the lesion was symptomatic. Mean follow-up was 42.5 ± 32.6 months (range 1-141 months). The mortality rate at 5 years was 23%. The neurologic event-free survival and the in-stent restenosis rates at 5 years were 87.8% and 38.9%, respectively. Diabetes mellitus (p=0.02) and single postoperative antiplatelet therapy (p=0.001) were found to be significant predictors of in-stent restenosis. Freedom from target lesion revascularization was 91.9% at 5 years.

CONCLUSION

This study showed that CAS is an effective option for RT-induced stenosis in patients not favorable to carotid endarterectomy. The CAS was associated with a low rate of neurological events and reinterventions at long-term follow-up.

Outcomes of carotid artery stenting in patients with radiation arteritis compared with those with atherosclerotic disease

OBJECTIVE

Head and neck malignancies are often treated with radiotherapy (RT). Nearly 80% of patients who have undergone RT will develop carotid radiation arteritis to some degree and 29% will develop stenosis >50%. Surgery in a radiated neck has higher rates of complications, and carotid artery stenting (CAS) has become the primary therapy. The outcomes for CAS in patients with radiation arteritis have not been rigorously evaluated. The objective of the present study was to evaluate the differences in perioperative outcomes, restenosis rates, the need for reintervention, and freedom from mortality between RT patients and patients with atherosclerotic disease who had undergone CAS.

METHODS

The national Vascular Quality Initiative CAS dataset from 2016 to 2019 comprised the sample for analyses (n = 7343). The primary independent variable was previous head and/or neck RT. The primary endpoint was the interval to mortality. The secondary endpoints were the cumulative incidence of restenosis (>50% and >70% by duplex ultrasound) and reintervention. We also examined the following secondary perioperative endpoints: myocardial infarction, in-hospital mortality (death before discharge), neurologic events, ipsilateral stroke, and contralateral stroke. Kaplan-Meier and multivariable Cox proportional hazard models were used to assess for mortality, and cumulative incidence function estimates were used for the nonfatal endpoints.

RESULTS

Of the 7218 patients, 1199 (17%) had undergone prior RT. We found a significant difference in the 3-year estimates of mortality for those with and without prior RT (9.4% and 7.5%, respectively; P = .03). Furthermore, on adjusted analysis, we observed a 58% increase in the risk of mortality for those with prior RT (adjusted hazard ratio, 1.58; 95% confidence interval, 1.13-2.21). We did not observe any differences in the risk of perioperative complications (myocardial infarction, in-hospital mortality, ipsilateral or contralateral stroke), restenosis (>50% or >70%), or reintervention for the prior RT group compared with those without RT.

CONCLUSIONS

The CAS patients with RT had significantly greater mortality at all time points compared with those without RT, even after adjusting for other covariates. No significant difference was found in the incidence of perioperative complications, reintervention, or restenosis between the two groups. The present study is unique because of the large sample size and length of follow-up. The results suggest that for this high-risk group, CAS provides the same patency as it does for atherosclerotic carotid stenosis and avoids potentially morbid cranial nerve injury and wound healing complications.

Initial Data Pooling for Radiation Dose-Volume Tolerance for Carotid Artery Blowout and Other Bleeding Events in Hypofractionated Head and Neck Retreatments

PURPOSE

Dose-volume data for injury to carotid artery and other major vessels in stereotactic body radiation therapy (SBRT)/SABR head and neck reirradiation were reviewed, modeled, and summarized.

METHODS AND MATERIALS

A PubMed search of the English-language literature (stereotactic and carotid and radiation) in April 2018 found 238 major vessel maximum point doses in 6 articles that were pooled for logistic modeling. Two subsequent studies with dose-volume major vessel data were modeled separately for comparison. Attempts were made to separate carotid blowout syndrome from other bleeding events (BE) in the analysis, but we acknowledge that all except 1 data set has some element of BE interspersed.

RESULTS

Prior radiation therapy (RT) dose was not uniformly reported per patient in the studies included, but a course on the order of conventionally fractionated 70 Gy was considered for the purposes of the analysis (with an approximately ≥6-month estimated interval between prior and subsequent treatment in most cases). Factors likely associated with reduced risk of BE include nonconsecutive daily treatment, lower extent of circumferential tumor involvement around the vessel, and no surgical manipulation before or after SBRT.

CONCLUSIONS

Initial data pooling for reirradiation involving the carotid artery resulted in 3 preliminary models compared in this Hypofractionated Treatment Effects in the Clinic (HyTEC) report. More recent experiences with alternating fractionation schedules and additional risk-reduction strategies are also presented. Complications data for the most critical structures such as spinal cord and carotid artery are so limited that they cannot be viewed as strong conclusions of probability of risk, but rather, as a general guideline for consideration. There is a great need for better reporting standards as noted in the High Dose per Fraction, Hypofractionated Treatment Effects in the Clinic introductory paper.

Higher Risk for Reintervention in Patients after Stenting for Radiation-Induced Internal Carotid Artery Stenosis: A Single-Center Analysis and Systematic Review

BACKGROUND

This study aimed to review short- and long-term outcomes of all carotid artery stenting (CAS) in patients with radiation-induced (RI) internal carotid artery (ICA) stenosis compared with patients with atherosclerotic stenosis (AS).

METHODS

We performed a single-center, multisite case-control study of transfemoral carotid artery intervention in patients stented for RI or AS. Cases of stented RI carotid arteries were identified using a CAS database covering January 2000 to December 2019. These patients were randomly matched 2:1 with stented patients because of AS by age, sex, and year of CAS. A conditional logistic regression model was performed to estimate the odds of reintervention in the RI group. Finally, a systematic review was performed to assess the outcomes of RI stenosis treated with CAS.

RESULTS

There were 120 CAS in 113 patients because of RI ICA stenosis. Eighty-nine patients (78.8%) were male, and 68 patients (60.2%) were symptomatic. The reasons for radiation included most commonly treatment for diverse malignancies of the head and neck in 109 patients (96.5%). The mean radiation dose was 58.9 ± 15.6 Gy, and the time from radiation to CAS was 175.3 ± 140.4 months. Symptoms included 31 transient ischemic attacks (TIAs), 21 strokes (7 acute and 14 subacute), and 17 amaurosis fugax. The mean National Institutes of Health Stroke Scale in acute strokes was 8.7 ± 11.2. In asymptomatic patients, the indication for CAS was high-grade stenosis determined by duplex ultrasound. All CAS were successfully completed. Reinterventions were more frequent in the RI ICA stenosis cohort compared with the AS cohort (10.1% vs. 1.4%). Reinterventions occurred in 14 vessels, and causes for reintervention were restenosis in 12 followed by TIA/stroke in two vessels. On conditional regression modeling, patients with RI ICA stenosis were at a higher risk for reintervention (odds ratio = 7.1, 95% confidence interval = 2.1-32.8; P = 0.004). The mean follow-up was 33.7 ± 36.9 months, and the mortality across groups was no different (P = 0.12).

CONCLUSIONS

In our single-center, multisite cohort study, patients who underwent CAS for RI ICA stenosis experienced a higher rate of restenosis and a higher number of reinterventions compared with CAS for AS. Although CAS is safe and effective for this RI ICA stenosis cohort, further data are needed to reduce the risk of restenosis, and close patient surveillance is warranted. In our systematic review, CAS was considered an excellent alternative option for the treatment of patients with RI ICA stenosis. However, careful patient selection is warranted because of the increased risk of restenosis on long-term follow-up.

Clinical outcomes of radiation-induced carotid stenosis: A systematic review and meta-analysis

OBJECTIVES

Clinical outcomes of radiation-induced carotid stenosis are still unclear. Therefore, a systematic review and meta-analysis is needed to evaluate the short- and long-term outcomes after interventions to treat radiation-induced carotid stenosis.

METHODS

PubMed, EMBASE, the Cochrane Library and Web of Science were searched from 1 January 2000 for relevant RCTs and observational studies which reported outcomes after carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS) for carotid stenosis induced by radiation. Risk of bias were assessed through different scales according to study design. I² statistic were used to evaluate the heterogeneity, and meta-regression were performed to investigate the source of heterogeneity. Visual inspection of funnel plots was used to judge publication bias.

RESULTS

A total of 26 studies with 1002 patients were included. CEA was performed in 364 patients and CAS in 638 patients. The overall estimated rate of short-term stroke was 0.19% (95% CI: 0-0.90%), and the rate of long-term stroke was 2.68 % (95% CI: 1.19-4.57%). The rate of cranial nerve injury in CEA group was significantly higher than that in CAS group [risk ratio (RR): 6.03, 95% CI: 1.63-22.22, P = .007]. The univariate regression analysis showed that the risk of stroke in CAS group were significantly higher than CEA group in both short- and long-term [incidence rate ratio (IRR): 3.62, 95% CI: 1.21-10.85, P = 0.22; IRR: 2.95, 95% CI: 1.02-8.59, P = .046, respectively].

CONCLUSIONS

This systematic review provided the worldwide profile of outcome of treatment for radiation-induced carotid stenosis, and also found that CEA can yield better results for these patients than CAS. Nonetheless, as large-scale studies have not yet been conducted, and there is a definite need for further studies in the future.

Risk Scoring Systems to Predict Long-Term Mortality After Carotid Endarterectomy in Asymptomatic Patients: A Systematic Review

The present review was conducted to describe current published risk scoring systems to predict late mortality after carotid endarterectomy (CEA). The aim of the study is to identify simple, clinical, and reproducible tools to predict life expectancy in patients with asymptomatic carotid artery stenosis candidates to CEA and therefore which patients may benefit from surgery, reaching the goal of life expectancy >3 to 5 years, recommended by guidelines. Advantages, disadvantages, feasibility, simplicity, and reproducibility of each selected score were analyzed. Rigorous statistical analysis and validation of the score are essential components to produce a calibrated and usable score. Future studies should address the impact of using these tools in CEA candidates for asymptomatic disease.