Carotid artery stenting: clinical and procedural implications for near-occlusion stenosis

Endarterectomy, Stenting, or Medical Treatment for Symptomatic Carotid Near-Occlusion: Results from CAOS, a Multicenter Registry Study

BACKGROUND AND PURPOSE

The treatment of symptomatic carotid near-occlusion is controversial. Our aim was to analyze the results of carotid endarterectomy and carotid artery stent placement in patients with symptomatic carotid near-occlusion and to identify factors related to technical failure, periprocedural complications, and restenosis.

MATERIALS AND METHODS

We conducted a multicenter, prospective nonrandomized study. Patients with angiography-confirmed carotid near-occlusion were included. We assessed the revascularization rate and periprocedural stroke or death. Twenty-four-month clinical and carotid imaging follow-up was performed, and rates of carotid restenosis or occlusion, ipsilateral stroke, and mortality were analyzed. Carotid artery stent placement, carotid endarterectomy, and medical treatment were compared.

RESULTS

One hundred forty-one patients were included. Forty-four carotid artery stent placement and 23 carotid endarterectomy procedures were performed within 6 months after the event. Complete revascularization was achieved in 83.6%, 81.8% in the carotid artery stent placement group and 87% with carotid endarterectomy (P = .360). Periprocedural stroke or death occurred in 6% (carotid artery stent placement = 2.3%; carotid endarterectomy = 13%; P = .077) and was not related to revascularization failure. The carotid restenosis or occlusion rate was 8.3% (5% restenosis, 3.3% occlusion); with carotid artery stent placement it was 10.5%; and with carotid endarterectomy it was 4.5% (P = .419). The 24-month cumulative rate of ipsilateral stroke was 4.8% in the carotid artery stent placement group, 17.4% for carotid endarterectomy, and 13.1% for medical treatment (P = .223). Mortality was 12%, 4.5%, and 5.6%, respectively (P = .422). Revascularization failure and restenosis occurred more frequently in patients with full collapse compared with patients without full collapse (33.3% versus 5.6%, P = .009; 21.4% versus 2.9%, P = .032, respectively).

CONCLUSIONS

Carotid artery stent placement and carotid endarterectomy are associated with high rates of failure and periprocedural stroke. Carotid near-occlusion with full collapse appears to be associated with an increased risk of technical failure and restenosis. Carotid near-occlusion revascularization does not seem to reduce the risk of stroke at follow-up compared with medical treatment.

Near-Occlusion is a Common Variant of Carotid Stenosis: Study and Systematic Review

BACKGROUND

Symptomatic carotid near-occlusion is often described as rare. Recent studies have shown that near-occlusions are overlooked, especially near-occlusion without full collapse (with a small but normal-appearing distal internal carotid artery).

OBJECTIVE

To assess the prevalence of near-occlusion among symptomatic ≥50% carotid stenosis, incidence of symptomatic near-occlusion, and review the literature.

METHODS

Prospective controlled single-center cross-sectional study. Consecutive cases with symptomatic ≥50% carotid stenosis were examined with computed tomography angiography (CTA). The CTAs were assessed for near-occlusion by two observers. A systematic literature review was performed with emphasis on how study design affects prevalence estimate.

RESULTS

Totally, 186 patients with symptomatic ≥50% carotid stenosis were included, 34% (n = 63, 95% CI 27, 41) had near-occlusion. The incidence of symptomatic near-occlusion was 3.4 (95% CI 2.5, 4.2) per 100,000 person-years. Inter-rater κ was 0.71. The average prevalence of near-occlusion among symptomatic ≥50% carotid stenosis was higher in studies with good design (30%, range 27%-34%) than studies without good design (9%, range 2%-10%).

CONCLUSIONS

Near-occlusion is common variant of symptomatic ≥50% carotid stenosis, both in the current study and in all previous studies of good design. Studies that suggest that near-occlusion is rare have had methodological issues.

Management of internal carotid artery near-occlusion: the need for updated evidence

Near occlusion of internal carotid artery (ICA) is a rare and easily misdiagnosed condition and the decision for revascularisation still remains controversial. We conducted an updated meta-analysis in order to investigate outcomes after carotid endarterectomy (CEA), carotid artery stenting (CAS) or best medical treatment (BMT) in patients with near-occlusion of the ICA. We also aimed to investigate the role of time as a potential moderator of the near-ICA occlusion-stroke rate association. A multiple electronic health database search on articles published up to November 2019 was performed. The pooled stroke rate after CEA, CAS and BMT were calculated. We also investigated transient ischemic attack (TIA), stroke-related death, myocardial infarction (MI), any cause of death and ICA restenosis crude rates (%). A total of 33 articles were finally deemed eligible. The pooled stroke rate was 1.52% [95% confidence interval (CI): 0.09-4.02%] after CEA, 1.80% (95% CI: 0.61-3.40%) after CAS and 8.39% (95% CI: 3.39-14.80%) after BMT. Out of 896 CEA patients, we recorded 22 TIAs (2.5%), 33 all-cause deaths (3.7%), 5 stroke-related deaths (0.6%) and 6 MIs (0.7%). Concerning outcomes after 603 CAS patients, we recorded 7 TIAs (1.2%), 56 all-cause deaths (9.3%), 4 stroke-related deaths (0.7%) and 22 MIs (3.6%). Among 263 patients who were treated with BMT, we found 16 TIAs (6.1%), 10 all-cause deaths (3.8%), no stroke-related death, and no MI. Crude restenosis rate during follow-up was 9.0% (54/601) for CEA and 4.1% (24/592) for CAS patients. No significant effect of publication year upon stroke rate after CEA was recorded. However, there was a significant reversed association between pooled stroke rate after CAS and publication year (P=0.05). A statistically significant reversed association between pooled stroke rate after BMT and publication year was also recorded (P<0.01). The results of this updated meta-analysis revealed high stroke rate for patients with near-occlusion of ICA who treated only with BMT, while intervention seemed to be safe and effective. A downward trend in the stroke rates over time after CAS and BMT was also discovered. These highlight that patients with near-occlusion of ICA should be included and investigated in future studies.

Relevance of Distal Arterial Collapse in Stenting of Atherosclerotic Near-Occlusion of the Carotid Artery

BACKGROUND AND PURPOSE

Carotid near-occlusion has been subclassified into near-occlusion with and without collapse. We aimed to compare the technical success and perioperative complication rates of carotid artery stent placement with special attention to these subtypes to see whether there is a clinical relevance of this subclassification.

MATERIALS AND METHODS

From January 2014 to January 2018, we retrospectively evaluated all patients with atherosclerotic extracranial carotid stenosis treated by carotid artery stent placement. Patients with near-occlusion were identified based on DSA findings. Patient characteristics, the presence of criteria for near-occlusion and collapse, arterial diameters, technical success rate, and perioperative (≤30 days) complications were analyzed.

RESULTS

We identified 59 near-occlusions in 58 (46 men, 11 with collapse) patients. Forty-one patients (70.7%) were symptomatic. Technical success rate was 98.3% (58 of 59 procedures). In 1 case of near-occlusion with collapse, we were not able to pass through the stenosis. Compared with patients without collapse (4.2% of 48 cases), those with collapse (30% of 10 stented patients) had significantly higher rates of postintervention hyperperfusion syndrome (P = .032). In the whole cohort, the permanent morbidity and mortality rate was 3.4% (1.7% permanent morbidity and 1.7% mortality). For asymptomatic and symptomatic near-occlusion groups, the rates were 0% and 4.9%, respectively. The composite risk of stroke, death, and myocardial infarction was similar between the groups with and without collapse (P = .682). Rate of hyperperfusion syndrome (with or without permanent deficit) was similar (P = 1) in preoperatively symptomatic patients versus asymptomatic patients (9.8% vs 5.9%). Internal carotid artery diameter consistently increased after carotid artery stent placement in patients with collapse and was not related to the development of hyperperfusion syndrome.

CONCLUSIONS

Care should be taken to minimize hyperperfusion risk in patients with near-occlusion undergoing CAS, especially in the subgroup of patients with collapse and in patients with both symptomatic and asymptomatic carotid stenosis.

Carotid Near-Occlusion Stent Experiences

Introduction

Treatment strategy for near-occlusions (NO) of the internal carotid artery (ICA) is still controversial. In this study, we aimed to present the clinical results of stent placement in 50 patients with carotid artery (NO) stenosis that presented to our center, and upon which revascularization will be performed.

Methods

Between 2014 and 2017, 50 patients with (NO) from 180 patients who had stents in the Interventional Vascular Neurology clinic were retrospectively studied. All the patients whether using or not using the proximal and distal protection device during the procedure were included. Patients had clinical neurologic evaluation, and underwent carotid artery radiologic imaging before the carotid artery stent (CAS) procedure. Balloon dilatation was applied before the stent procedure for patients that had advanced stenosis. Post-dilatation was applied with a balloon of appropriate size in case of residual narrowing. Findings such as bradycardia, hypotension, reperfusion hemorrhage during and after the stent placement procedure, as well as patients that developed restenosis within 12 months were recorded.

Results

This study includes 50 (30 males, 20 females) patients that underwent carotid stent placement. The mean age of patients was 65 (28-81). Reperfusion hemorrhage was seen in 1 (2%) patient and the patient died in week 3. Ten (20%) patients complained of chills and tremor lasting less than 3 hours after the procedure. One (2%) patient had encephalopathy and agitation for less than 24 hours. Two (4%) patients had hypotension, and 15 (30%) patients had a headache for less than 24 hours. Three patients developed local hematoma at the site of the sheath, and were treated by applying compression. Restenosis signs in the stent site was observed in 6 patients (12%) in color Doppler ultrasonography of the carotid performed in the 6th and 12th months.

Conclusion

Although the innate process of ICA NO is not well known, it might be more frequent than currently considered. Especially after the diagnosis of ICA stenosis, it is important to make the right diagnosis in patients that have new ipsilateral symptoms. After the diagnosis is made, CAS, when performed by an experienced neuro-interventional team, seems beneficial with low complication rates.

Carotid endarterectomy in patients with recurrent symptoms associated with an ipsilateral carotid artery near occlusion with full collapse

OBJECTIVE

Near occlusion (NO) of the internal carotid artery (ICA) with full collapse (NOFC) is a rare condition, with a prevalence of around 1%. Guidelines on carotid stenosis recommend a conservative treatment in patients with a single-event ipsilateral to a NOFC, but the optimal treatment for patients with recurrent symptoms associated with NOFC remains uncertain. We describe a consecutive series of patients with recurrent symptoms associated with NOFC (RSNOFC) who underwent carotid endarterectomy (CEA).

METHODS

From 2008 to 2017, 17 consecutive patients with RSNOFC were treated according to our standardized multidisciplinary work-up and protocol and included for this single-center cohort study. NO was defined according to the angiographic North American Symptomatic Carotid Endarterectomy Trial criteria. Only patients with NOFC were included in this study.

RESULTS

Standard longitudinal CEA was performed in 15 patients, whereas in 2 patients the ICA was ligated with concomitant endarterectomy of the ECA. Within 30 postoperative days, one patient died from a hemorrhagic infarction. During follow-up (median 23 months) one patient died of unknown cause 90 days after CEA. No TIA, stroke, myocardial infarction or re-stenosis occurred in the remaining patients.

CONCLUSION

In patients with RSNOFC, CEA may be considered a potential treatment option. Although procedural risks in this small subgroup may be higher as compared to patients with low-to-moderate risk anatomy, this risk may outbalance the natural course.

Endovascular Treatment for Near Occlusion of the Internal Carotid Artery : 30-Day Outcome and Long-Term Follow-Up

BACKGROUND

The treatment strategy and the correct incidence of near occlusion (NO) of the internal carotid artery (ICA) is still controversial. In routine radiological imaging NO can easily be misdiagnosed as complete occlusion and there is no consensus on the standard treatment strategy.

PURPOSE

To present our perioperative and long-term follow-up results of ICA NO patients treated with carotid artery stenting (CAS).

MATERIAL AND METHODS

Between 2004-2014 a total of 182 patients with ICA NO were evaluated for CAS. The study included 132 male (72.5 %) and 50 female (27.5 %) patients with a mean age of 70.2 years. Patients underwent a clinical neurological evaluation and radiological imaging of the carotid arteries before the CAS procedure. Of the patients 80 (44 %) were asymptomatic. The median clinical and carotid Doppler ultrasound (DUS) follow-up period was 64 months (range 18-124 months).

RESULTS

In 182 patients CAS were performed, 4 patients (2.2 %) developed minor stroke, 2 patients (1.1 %) developed myocardial infarction but no major stroke or death occurred in the following 30-day period. Asymptomatic restenosis was detected in seven patients (3.8 %) in the follow-up period.

CONCLUSION

With sufficient neurological evaluation during pretreatment and posttreatment periods and when the procedure is performed with technologically developed products by an experienced interventional team, CAS is beneficial in patients with ICA NO.

Carotid Near-Occlusion: A Comprehensive Review, Part 2--Prognosis and Treatment, Pathophysiology, Confusions, and Areas for Improvement

In Part 1 of this review, the definition, terminology, and diagnosis of carotid near-occlusion were presented. Carotid near-occlusions (all types) showed a lower risk of stroke than other severe stenoses. However, emerging evidence suggests that the near-occlusion prognosis with full collapse (higher risk) differs from that without full collapse (lower risk). This systematic review presents what is known about carotid near-occlusion. In this second part, the foci are prognosis and treatment, pathophysiology, the current confusion about near-occlusion, and areas in need of future improvement.

Carotid Near-Occlusion: A Comprehensive Review, Part 1--Definition, Terminology, and Diagnosis

Carotid near-occlusion is distal ICA luminal collapse beyond a tight stenosis, where the distal lumen should not be used for calculating percentage stenosis. Near-occlusion with full ICA collapse is well-known, with a threadlike lumen. However, near-occlusion without collapse is often subtle and can be overlooked as a usual severe stenosis. More than 10 different terms have been used to describe near-occlusion, sometimes causing confusion. This systematic review presents what is known about carotid near-occlusion. In this first part, the foci are definition, terminology, and diagnosis.