Revascularization of radiation-induced carotid artery stenosis with carotid endarterectomy vs. carotid artery stenting: A systematic review and meta-analysis

Progression rate of radiation-induced carotid stenosis in head and neck cancer survivors after statin treatment: a retrospective cohort study

BACKGROUND AND AIMS

Whether statin treatment is effective in retarding the progression of radiation-induced carotid stenosis (RICS) in head and neck cancer (HNC) survivors has not been well studied. The purpose of this study was to assess the association of statin treatment with RICS progression rate in HNC survivors after radiotherapy.

METHODS

We conducted a retrospective cohort study at Sun Yat-sen Memorial Hospital, Sun Yat-sen University in Guangzhou, China. Between January 2010 and December 2021, we screened HNC survivors whose carotid ultrasound scans had shown stenosis of the common and/or internal carotid arteries. The primary outcome was the RICS progression rate. We compared eligible patients treated with statins with those who did not in multivariable Cox regression models.

RESULTS

A total of 200 patients were included in this study, of whom 108 received statin treatment and 92 did not. Over a mean follow-up time of 1.5 years, 56 (28.0%) patients showed RICS progression, 24 (42.9%) and 32 (57.1%) in the statin and control groups, respectively. The statin group showed less RICS progression than the control group (adjusted-HR 0.49, 95% CI 0.30-0.80, P = 0.005). In the subgroup analysis, there was no significant interaction in the effect of statins on lowering RICS progression rate in the subgroups stratified by baseline low-density lipoprotein cholesterol (LDL-C) levels (P for interaction = 0.53) or baseline degrees of stenosis (P for interaction = 0.50).

CONCLUSIONS

Statin treatment was associated with a lower risk of RICS progression in patients with HNC after radiotherapy, regardless of baseline LDL-C level and baseline stenosis degrees.

Continuous and Early Progression of Carotid Intima-Media Thickness after Radiotherapy for Head and Neck Cancer: 5-Year Prospective Observational Study

INTRODUCTION

Radiation-induced carotid artery stenosis (RI-CS) is known as one of long-term side effects of radiotherapy for head and neck cancer (HNC). However, the clinical time course after irradiation has been poorly understood. We aimed to investigate the natural history of radiation-induced carotid atherosclerosis, comparing the patients who received radiotherapy for HNC with the patients who were treated without radiotherapy.

METHODS

The patients who received treatment of HNC at Department of Otolaryngology, Head and Neck Surgery of Kyoto University Hospital, from November 2012 to July 2015 were enrolled. The patients were assigned into the RT group and the control group, depending on whether radiotherapy was planned or not. Annual carotid ultrasound was performed from the enrollment to 5 years. The increase of mean intima-media thickness (IMT) at common carotid artery from the enrollment (Δmean IMT) was evaluated.

RESULTS

Fifty-six patients in the RT group and 25 patients in the control group were enrolled. From 5-year follow-up data, the significant higher increase of Δmean IMT was consistently observed in the RT group than in the control group after 2 years. The RT group presented a 7.8-fold increase of mean IMT compared to the control group (0.060 mm per year in the RT group and 0.008 mm per year in the control group). Cumulative incidence curves obtained from the analysis of all vessels revealed that the RT group presented higher incidence of Δmean IMT ≥0.25 mm than the control group (p < 0.01). In the RT group, the patients with mean IMT ≥1.0 mm at enrollment exhibited significantly higher incidence of Δmean IMT ≥0.25 mm than the patients with mean IMT <1.0 mm (p < 0.01).

DISCUSSION

Radiotherapy for HNC induces continuous carotid mean IMT progression. The irradiated carotid arteries with mean IMT ≥1.0 mm before radiotherapy presented earlier IMT progression than those with mean IMT <1.0 mm.

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.

Carotid Endarterectomy

Stroke is the second leading cause of death worldwide. One of the main causes of stroke is carotid artery stenosis. Stenosis with atherosclerosis in the carotid artery can cause stroke by hemodynamic ischemia or artery to artery embolism. A most common surgical intervention for carotid artery stenosis is carotid endarterectomy (CEA). Many studies on CEA have been reported and suggested medical indications. For symptomatic carotid stenosis, generally, CEA may be indicated for patients with more than 50% stenosis and is especially beneficial in men, patients aged 75 years or older, and patients who underwent surgery within 2 weeks of their last symptoms. For asymptomatic carotid stenosis, CEA may be indicated for those with more than 60% stenosis, though each guideline has different suggestions in detail. In order to evaluate the indication for CEA in each case, it is important to assess risks for CEA carefully including anatomical factors and comorbidities, and to elaborate each strategy for each operation based on preoperative imaging studies including carotid ultrasonography, magnetic resonance imaging and angiography. In surgery there are many tips on operative position, procedure, shunt usage and monitoring to perform a safe and smooth operation. Now that carotid artery stenting has been rapidly developed, better understanding for CEA is required to treat carotid artery stenosis adequately. This chapter must be a good help to understand CEA well.

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.

Imaging of Complications of Chemoradiation

Chemoradiation for head and neck cancer is associated with a variety of early and late complications. Toxicities may affect the aero-digestive tract (mucositis, salivary gland injury), regional osseous and cartilaginous structures (osteoradionecrosis (ORN) and chondronecrosis), vasculature (progressive radiation vasculopathy and carotid blow out syndromes), and neural structures (optic neuritis, myelitis, and brain injury). These may be difficult to distinguish from tumor recurrence on imaging, and may necessitate the use of advanced MRI and molecular imaging techniques to reach the correct diagnosis. Secondary radiation-induced malignancies include thyroid cancer and a variety of sarcomas that may manifest several years after treatment. Checkpoint inhibitors can cause a variety of adverse immune events, including autoimmune hypophysitis and encephalitis.

A Case of Severe Common Carotid Artery Stenosis Who Developed Cerebellar Infarction after Cervical Irradiation

Objective

We report a case of cerebellar infarction caused by radiation-induced common carotid artery stenosis.

Case Presentation

The patient was a 72-year-old man who underwent irradiation for hypopharyngeal carcinoma 13 years ago. He was referred for asymptomatic left common carotid artery stenosis, but was brought to our hospital by ambulance with transient dysarthria and right facial dysesthesia 2 days after referral. Magnetic resonance imaging (MRI) revealed acute infarction in the left cerebellar hemisphere, and digital subtraction angiography (DSA) demonstrated that the blood flow in the left internal carotid artery perfused the left posterior inferior cerebellar artery (PICA) retrogradely through the left posterior communicating artery. The patient underwent carotid artery stenting (CAS) for left common carotid artery stenosis and blood flow in the left PICA improved; however, in-stent restenosis was revealed during follow-up. Percutaneous transluminal angioplasty (PTA) for in-stent restenosis was performed 9 months after the surgery.

Conclusion

We reported a rare case of ischemia in the PICA area caused by radiation-induced common carotid artery stenosis. Although CAS is recommended for the treatment of radiation-induced carotid artery stenosis, careful treatment and follow-up are needed to prevent perioperative complications and detect in-stent restenosis after CAS.

Mechanical Thrombectomy and Stenting for Radiation-Induced Carotid Stenosis-Related Stroke: A Case Report

Radiation-induced stenosis of the carotid artery is a significant risk factor for large-vessel ischemic stroke, which usually leads to significant impairment of neurological function. We performed intra-arterial thrombectomy on a 63-year-old male patient who had laryngeal cancer and postradiation carotid stenosis. He presented with acute-onset dysarthria and left hemiplegia. Brain computed tomography perfusion scan showed right middle cerebral artery ischemic change. Angiography confirmed total occlusion of the right internal carotid artery. Intra-arterial mechanical thrombectomy with carotid stenting was performed immediately, and recanalization was achieved. The patient fully recovered and was discharged after a 1-week hospitalization. Our experience suggests that early intervention for radiation-related carotid stenosis might be essential and beneficial for the outcome of large-vessel ischemic stroke.

Medical prevention and treatment of radiation-induced carotid injury

Radiotherapy has significantly improved the survival of cancer patients but is also associated with several adversities, including radiation-induced carotid injury (RICI). The RICI mechanisms are complex, including vessel inflammatory injury, carotid atherosclerosis, intimal proliferation, media necrosis, and peri-adventitial fibrosis. The main manifestation and adverse consequence of RICI is carotid artery stenosis (CAS), which can lead to stroke and transient ischemic attack. Currently, carotid artery injury is primarily diagnosed via color-coded duplex sonography. Early detection of traumatic changes in the carotid artery depends on measurements of carotid intima-media thickness; serum biomarker testing also shows great potential. CAS is mainly treated with carotid endarterectomy or carotid angioplasty and stent implantation. Notably, bone marrow mesenchymal stem cells are advantageous in RICI treatment and reduce carotid inflammation, oxidative stress, and delaying atherosclerosis. This review summarizes the mechanisms, examination methods, and latest treatments for RICI to provide data for its clinical prevention and treatment.

Late side effects of radiation treatment for head and neck cancer

Patients undergoing radiation therapy for head and neck cancer (HNC) experience significant early and long-term side effects. The likelihood and severity of complications depends on a number of factors, including the total dose of radiation delivered, over what time it was delivered and what parts of the head and neck received radiation. Late side effects include: permanent loss of saliva; osteoradionecrosis; radiation recall myositis, pharyngoesophageal stenosis; dental caries; oral cavity necrosis; fibrosis; impaired wound healing; skin changes and skin cancer; lymphedema; hypothyroidism, hyperparathyroidism, lightheadedness, dizziness and headaches; secondary cancer; and eye, ear, neurological and neck structures damage. Patients who undergo radiotherapy for nasopharyngeal carcinoma tend to suffer from chronic sinusitis. These side effects present difficult challenges to the patients and their caregivers and require life-long strategies to alleviate their deleterious effect on basic life functions and on the quality of life. This review presents these side effects and their management.

Prevalence of carotid stenosis following radiotherapy for head and neck cancer: A systematic review and meta-analysis

BACKGROUND

Radiation to the head and neck is a well-established risk factor for the development of carotid artery stenosis. Our objective was to identify the prevalence, incidence, and degree of carotid stenosis in patients with a history of head and neck irradiation.

METHODS

This study was performed according to the PRISMA guidelines. A random effects model meta-analysis was conducted.

RESULTS

Nineteen studies comprising 1479 patients were included. The prevalence of carotid stenosis >50%, >70%, and carotid occlusion was 25% (95% CI: 19%-32%), 12% (95% CI: 7%-17%), and 4% (95% CI: 2%-8%), respectively. The cumulative 12-month incidence of carotid stenosis >50% was 4% (95% CI: 2%-5%), the 24-month was 12% (95% CI: 9%-15%), and the 36-month was 21% (95% CI: 9%-36%).

CONCLUSIONS

The yearly incidence of carotid stenosis >50% increased every year during the first 3 years following radiotherapy. We propose routine yearly Doppler ultrasound screening beginning 1 year after head and neck radiotherapy.

Synchronous versus Staged Carotid Endarterectomy and Coronary Artery Bypass Graft for Patients with Concomitant Severe Coronary and Carotid Artery Stenosis: A Systematic Review and Meta-analysis

BACKGROUND

Due to the systemic nature of atherosclerosis, arteries at different sites are commonly simultaneously affected. As a result, severe coronary artery disease (CAD) requiring coronary artery bypass grafting (CABG) frequently coexists with significant carotid stenosis that warrants revascularization. To compare simultaneous carotid endarterectomy (CEA) and CABG versus staged CEA and CABG for patients with concomitant CAD and carotid artery stenosis in terms of perioperative outcomes.

METHODS

This study was performed according to the Preferred Reporting Items for Systematic reviews and Meta-Analyses guidelines. A meta-analysis was conducted with the use of a random effects model. The I² statistic was used to assess for heterogeneity.

RESULTS

Eleven studies comprising 44,895 patients were included in this meta-analysis (21,710 in the synchronous group and 23,185 patients in the staged group). The synchronous CEA and CABG group had a statistically significant lower risk for myocardial infarction (MI) (odds ratio [OR] 0.15, 95% CI 0.04-0.61, I² = 0%) and higher risk for stroke (OR 1.51, 95% CI 1.34-1.71, I² = 0%) and death (OR 1.33, 95% CI 1.01-1.75, I² = 47.8%). Transient ischemic attacks (TIAs) (OR 1.27, 95% CI 1.00-1.61, I² = 0.0%), postoperative bleeding (OR 0.82, 95% CI 0.22-3.05, I² = 0.0%), and pulmonary complications (OR 1.52, 95% CI 0.24-9.60, I² = 67.5%) were similar between the 2 groups.

CONCLUSIONS

Patients in the simultaneous CEA and CABG group had a significantly higher risk of 30-day mortality and stroke and lower risk for MI as compared to staged CEA and CABG group. The rates of TIA, postoperative bleeding, and pulmonary complications were similar between the 2 groups. Future randomized trials or prospective cohorts are needed to validate our results.

Current Medical and Surgical Stroke Prevention Therapies for Patients with Carotid Artery Stenosis

Carotid Artery Stenosis (CAS) is a marker of systemic atherosclerosis and patients with CAS are at high risk of vascular events in multiple vascular locations, including ipsilateral ischemic stroke. Both medical and surgical therapies have been demonstrated effective in reducing this risk. The optimal management for patients with asymptomatic carotid artery stenosis remains controversial. In patients with symptomatic CAS ≥70%, CEA has been demonstrated to reduce the risk of stroke. With the risk of recurrent stroke being particularly high in the first 2 weeks after the first event, Carotid Endarterectomy (CEA) or carotid angioplasty with stenting provides maximal benefits to patients with symptomatic CAS ≥70% if performed within this «2-week» target. Several large ongoing trials are currently comparing the risks and benefits of carotid revascularization versus medical therapy alone.

Systematic and Comprehensive Comparison of Incidence of Restenosis Between Carotid Endarterectomy and Carotid Artery Stenting in Patients with Atherosclerotic Carotid Stenosis

OBJECTIVE

The purpose of the present study was to conduct a meta-analysis to systematically compare the incidence rates of in-stent restenosis after carotid artery stenting (CAS) and restenosis after carotid endarterectomy (CEA) for patients with atherosclerotic carotid stenosis.

METHODS

We retrieved potential academic reports comparing restenosis between CEA and CAS from the MEDLINE, PubMed, and EMBASE databases and the Cochrane Library from the date of the first CEA (January 1951) to July 20, 2018. The references of the identified studies were carefully reviewed to ensure that all available reports were included in the present study.

RESULTS

Our meta-analysis included 27 studies (15 randomized controlled trials, 12 nonrandomized controlled trials) and 20,479 participants with atherosclerotic carotid stenosis. A statistically significant difference was found in the cumulative incidence of restenosis >70% between CEA and CAS (risk difference, -0.033, 95% confidence interval [CI] -0.054 to -0.013; P = 0.002). For the restenosis >70% outcomes, although CEA was relevant with a lower rate of restenosis than CAS within 6 months (odds ratio [OR], 0.495; 95% CI, 0.285-0.861; P = 0.013) and 1 year (OR, 0.626; 95% CI, 0.483-0.811; P < 0.001), no statistically significant differences were found at 1.5 years (P = 0.210), 2 years (P = 0.123), 4 years (P = 0.124), 5 years (P = 0.327), or 10 years (P = 0.839). For the restenosis >50% outcomes, a significant difference was found in the rate of restenosis between the CEA and CAS groups within 1 year (OR, 0.317; 95% CI, 0.228-0.441; P < 0.001) but not at 1.5 years (P = 0.301), 2 years (P = 0.686), or 5 years (P = 0.920). No nominally significant effects were demonstrated with respect to the cumulative incidence of occlusion (P = 0.195) or the cumulative incidence of restenosis for symptomatic patients (P = 0.170) between CEA and CAS.

CONCLUSIONS

Although CAS was preferred over CEA, regardless of restenosis >50% or >70% after revascularization within 1 year, no significant difference was observed with extension of the follow-up period to >1 year. CAS was not associated with a greater cumulative incidence of occlusion or the cumulative incidence of restenosis for symptomatic patients.

Carotid Artery Endarterectomy Versus Carotid Artery Stenting for Patients with Contralateral Carotid Occlusion: A Systematic Review and Meta-Analysis

BACKGROUND

Results from studies investigating the effect of contralateral carotid occlusion (CCO) in patients with carotid artery stenosis undergoing carotid artery endarterectomy (CEA) or carotid artery stenting (CAS) are variable in the literature. We sought to determine whether CEA or CAS is the optimal revascularization approach for patients with CCO.

METHODS

This meta-analysis was performed according to the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. A random effects model meta-analysis was conducted, and the I² statistic was used to assess for heterogeneity. Subgroup and sensitivity analyses were performed as needed.

RESULTS

Five retrospective observational cohort studies comprising 6346 patients were included. Patients in the CEA group had a significantly lower risk of 30-day periprocedural mortality (odds ratio, 0.46; 95% confidence interval, 0.30-0.71; I² = 0%). However, no significant differences were identified in terms of stroke, myocardial infarction (MI), and major adverse cardiovascular events (MACEs) between the 2 groups. Subgroup analyses of symptomatic and asymptomatic patients did not yield significant differences for stroke, MI, and death.

CONCLUSIONS

Patients with CCO can safely undergo both CAS and CEA with similar risks of stroke, MI, and MACE. However, patients treated with CEA have a lower risk of 30-day periprocedural mortality. Future studies can help further clarify the ideal approach for these patients.