Surgical Treatment for Carotid Stenoses with Highly Calcified Plaques

Association of stroke or death with severity of carotid lesion calcification in patients undergoing carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) for heavily calcified lesions is controversial due to concern for stent failure and increased perioperative stroke risk. However, the degree to which calcification affects outcomes is poorly understood, particularly in transcarotid artery revascularization (TCAR). With the precipitous increase in TCAR use and its expansion to standard surgical-risk patients, we aimed to determine the impact of lesion calcification on CAS outcomes to ensure its safe and appropriate use.

METHODS

We identified patients in the Vascular Quality Initiative who underwent first-time transfemoral CAS (tfCAS) and TCAR between 2016 and 2021. Patients were stratified into groups based on degree of lesion calcification: no calcification, 1% to 50% calcification, 51% to 99% calcification, and 100% circumferential calcification or intraluminal protrusion. Outcomes included in-hospital and 1-year composite stroke/death, as well as individual stroke, death, and myocardial infarction outcomes. Logistic regression was used to evaluate associations between degree of calcification and these outcomes.

RESULTS

Among 21,860 patients undergoing CAS, 28% patients had no calcification, 34% had 1% to 50% calcification, 35% had 51% to 99% calcification, and 3% had 100% circumferential calcification/protrusion. Patients with 51% to 99% and circumferential calcification/protrusion had higher odds of in-hospital stroke/death (odds ratio [OR], 1.3; 95% confidence interval [CI], 1.02-1.6; P = .034; OR, 1.9; 95% CI, 1.1-2.9; P = .004, respectively) compared with those with no calcification. Circumferential calcification was also associated with increased risk for in-hospital myocardial infarction (OR, 3.5; 95% CI, 1.5-8.0; P = .003). In tfCAS patients, only circumferential calcification/protrusion was associated with higher in-hospital stroke/death odds (OR, 2.0; 95% CI, 1.2-3.4; P = .013), whereas for TCAR patients, 51% to 99% calcification was associated with increased odds of in-hospital stroke/death (OR, 1.5; 95% CI, 1.1-2.2; P = .025). At 1 year, circumferential calcification/protrusion was associated with higher odds of ipsilateral stroke/death (12.4% vs 6.6%; hazard ratio, 1.64; P = .002).

CONCLUSIONS

Among patients undergoing CAS, there is an increased risk of in-hospital stroke/death for lesions with >50% calcification or circumferential/protruding plaques. Increasing severity of carotid lesion calcification is a significant risk factor for stroke/death in patients undergoing CAS, regardless of approach.

The Atherogenic Index of Plasma Predicts Carotid in-Stent Restenosis: Development and Validation of a Nomogram

Purpose

To explore the predictive value of atherogenic index of plasma(AIP) for carotid in-stent restenosis(ISR).

Methods

Patients who underwent carotid artery stenting (CAS) in hospital from January 2016 to January 2021 were retrospectively enrolled. They were randomly divided into training and validation sets. Based on the results of carotid digital subtraction angiography (DSA) during the follow-up period, the patients were divided into ISR group and non-ISR group. The differences of AIP and lipid levels between the two groups were compared. The independent risk factors of ISR and the predictive value of AIP for ISR were analyzed. A nomogram was developed based on the independent risk factors, and the receiver operating characteristic (ROC) curve, the calibration curve and the decision curve analysis were conducted to assess the predictive ability and clinical practicability of the nomogram in both the training set and validation sets.

Results

A total of 361 patients were enrolled, including 98 in the ISR group and 263 in the non-ISR group. In the training set, AIP was significantly higher in the ISR group than in the non-ISR group (P < 0.05) and was independently associated with ISR (OR= 10.912, 95% CI: 2.520-47.248). When AIP was 0.10, it had the highest predictive value for ISR, with a sensitivity of 72. 1% and a specificity of 75.0%. Additionally, hypertension, residual stenosis, symptomatic stenosis and Hcy were also independent risk factors for ISR. The nomogram showed good discrimination performance and clinical practicability in both the training set (AUC = 0.827) and the validation set (AUC = 0.880).

Conclusion

AIP was an independent risk factor for ISR and was closely related to ISR. The nomogram developed by AIP and other variables had good predictive ability and clinical practicability for ISR.

Effects of plaque characteristics and artery hemodynamics on the residual stenosis after carotid artery stenting

OBJECTIVE

Carotid artery stenting (CAS) has become an alternative strategy to carotid endarterectomy for carotid artery stenosis. Residual stenosis was an independent risk factor for restenosis, with the latter affecting the long-term outcomes of CAS. This multicenter study aimed to evaluate the echogenicity of plaques and hemodynamic alteration by color duplex ultrasound (CDU) examination and investigate their effects on the residual stenosis after CAS.

METHODS

From June 2018 to June 2020, 454 patients (386 males and 68 females) with a mean age of 67.2 ± 7.9 years, who underwent CAS from 11 advanced stroke centers in China were enrolled. One week before recanalization, CDU was used to evaluate the responsible plaques, including the morphology (regular or irregular), echogenicity of the plaques (iso-, hypo-, or hyperechoic) and calcification characteristics (without calcification, superficial calcification, inner calcification, and basal calcification). One week after CAS, the alteration of diameter and hemodynamic parameters were evaluated by CDU, and the occurrence and degree of residual stenosis were determined. In addition, magnetic resonance imaging was performed before and during the 30-day postprocedural period to identify new ischemic cerebral lesions.

RESULTS

The rate of composite complications, including cerebral hemorrhage, symptomatic new ischemic cerebral lesions, and death after CAS, was 1.54% (7/454 cases). The rate of residual stenosis after CAS was 16.3% (74/454 cases). After CAS, both the diameter and peak systolic velocity (PSV) improved in the preprocedural 50% to 69% and 70% to 99% stenosis groups (P < .05). Compared with the groups without residual stenosis and with <50% residual stenosis, the PSV of all three segments of stent in the 50% to 69% residual stenosis group were the highest, and the difference in the midsegment of stent PSV was the largest (P < .05). Logistic regression analysis showed that preprocedural severe (70% to 99%) stenosis (odds ratio [OR], 9.421; P = .032), hyperechoic plaques (OR, 3.060; P = .006) and plaques with basal calcification (OR, 1.885; P = .049) were independent risk factors for residual stenosis after CAS.

CONCLUSIONS

Patients with hyperechoic and calcified plaques of the carotid stenosis are at a high risk of residual stenosis after CAS. CDU is an optimal, simple and noninvasive imaging method to evaluate plaque echogenicity and hemodynamic alterations during the perioperative period of CAS, which can help surgeons to select the optimal strategies and prevent the occurrence of residual stenosis.

Impact of calcified plaque volume on technical and 3-year outcomes after transcarotid artery revascularization

OBJECTIVE

We sought to quantify the percent calcification within carotid artery plaques and assess its impact on percent residual stenosis and rate of restenosis in patients undergoing transcarotid artery revascularization for symptomatic and asymptomatic carotid artery stenosis.

METHODS

A retrospective review of prospectively collected institutional Vascular Quality Initiative data was performed to identify all patients undergoing transcarotid artery revascularization from December 2015 to June 2021 (n = 210). Patient and lesion characteristics were extracted. Using a semiautomated workflow, preoperative computed tomography head and neck angiograms were analyzed to determine the calcified plaque volume in distal common carotid artery and internal carotid artery plaques. Intraoperative digital subtraction angiograms were reviewed to calculate the percent residual stenosis post-intervention according to North American Symptomatic Carotid Endarterectomy Trial criteria. Peak systolic velocity and end-diastolic velocity were extracted from outpatient carotid duplex ultrasound examinations. Univariate logistic regression was performed to analyze the relationship of calcium volume percent and Vascular Quality Initiative lesion calcification to percent residual stenosis in completion angiograms. Kaplan-Meier analysis examined the relationship between calcium volume percent and in-stent stenosis over 36 months.

RESULTS

One hundred ninety-seven carotid arteries were preliminarily examined. Predilation was performed in 87.4% of cases with a mean balloon diameter of 5.1 ± 0.7 mm and a mean stent diameter was 8.8 ± 1.1 mm. The mean calcium volume percent was 11.9 ± 12.4% and the mean percent residual stenosis was 16.1 ± 15.6%. Univariate logistic regression demonstrated a statistically significant difference between calcium volume percent and percent residual stenosis (odds ratio [OR], 1.324; 95% confidence interval [CI], 1.005-1.746; P = .046). Stratified by quartile, only the top 25% of calcified plaques (>18.7% calcification) demonstrated a statistically significant association with higher percent residual stenosis (OR, 2.532; 95% CI, 1.049-6.115; P =.039). There was no statistical significance with lesion calcification (OR, 1.298; 95% C,: 0.980-1.718; P = .069). A Kaplan-Meier analysis demonstrated a statistically significant increase in the rate of in-stent stenosis during a 36-month follow-up for lesions containing >8.2% calcium volume (P = .0069).

CONCLUSIONS

A calcium volume percent of >18.7% was associated with a higher percent residual stenosis, and a calcium volume percent of >8.2% was associated with higher in-stent stenosis at 36 months. There was one clinically diagnosed stroke during the follow-up period, demonstrating the overall safety of the procedure.

Awareness of Stroke Risk Factors and Warning Signs Among Diabetic Patients in the Aseer Region, Saudi Arabia: A Cross-Sectional Study

Objective This study aimed to determine the awareness of stroke risk factors and warning signs among diabetic patients in the Aseer Region, Saudi Arabia. Methods We adopted a cross-sectional study involving 314 participants in the Aseer Region, Saudi Arabia between February 27, 2023, and April 20, 2023. The target population was diabetic patients whose database was obtained from various health institutions. The questionnaire was then distributed to the respondents after obtaining informed consent. The data were analyzed using SPSS Statistics version 27.0.1.0 (IBM Corp., Armonk, NY, USA) to obtain important insights. Results The majority of the respondents (69.11%) demonstrated a good level of knowledge, while 30.89% had poor knowledge. A good proportion of the respondents (68.47%) knew about stroke, while 73.89% knew it primarily affects the brain. Most respondents claimed that elderly people were at higher risk of attack (52.55%) and that the younger population was also prone to stroke (64.97%). The respondents identified hypertension (74.52%), smoking (72.61%), diabetes (71.66%), and high blood cholesterol (68.47%) as the main risk factors for stroke. The participants also demonstrated a very good understanding of the warning signs, with difficulty speaking (80.57%) and the weakness or inability to move one-half of the body (85.35%) being the most common signs. Conclusion The findings in this study indicated a good level of understanding and awareness of stroke, its risk factors, and warning signs (69.11%). The older respondents and people with a higher level of education demonstrated more knowledge. The two variables, age and education, had a statistically significant relationship with the knowledge of stroke. The common risk factors associated with stroke were identified as hypertension, smoking, diabetes, and high blood cholesterol. The respondents demonstrated good knowledge of the warning signs, with the vast majority asserting that difficulty in speaking, decreased sensation, and weakness or inability to move one-half of the body are common warning signs.

Usefulness of cone-beam computed tomography to predict residual stenosis after carotid artery stenting

OBJECTIVES

The long-term durability of carotid artery stenting (CAS) may be determined by various factors; however, residual stenosis is a known risk factor for in-stent restenosis. The authors of this article utilized cone-beam computed tomography (CBCT) in angiosuite to investigate plaque features affecting the character and quality of stent expansion after CAS.

METHODS

Forty-two CAS cases with both pre- and post-CAS CBCT evaluations were included in this retrospective analysis. Five features derived from pre-CAS images were tested: (1) eccentricity, (2) overballoon, (3) maximum plaque thickness, (4) calcification barrier, and (5) stenotic degree. For post-CAS CBCT, stent configuration was assessed if the stent was expanded and oval or round in shape as well as outward or inward in orientation. Variables were tested if they were associated with oval expansion, outward expansion, and 20% residual stenosis after CAS.

RESULTS

Oval or outward expansion is directly related to residual stenosis. The oval expansion was associated with maximum plaque thickness, and outward expansion was associated with the presence of a calcification barrier. Variables related to > 20% residual stenosis were the maximum plaque thickness, calcification barrier, and pre-CAS stenotic degree.

CONCLUSIONS

CBCT for carotid stenosis may provide valuable information about plaque features, especially calcification features that may interfere with the angioplasty effect, as well as the characteristics and quality of stent expansion. Residual stenosis > 20% was associated with calcification barrier, maximum plaque thickness, and pre-CAS stenotic degree.

Complete hemispheric exposure vs. superior sagittal sinus sparing craniectomy: incidence of shear-bleeding and shunt-dependency

PURPOSE

Decompressive hemicraniectomy (DC) has been established as a standard therapeutical procedure for raised intracranial pressure. However, the size of the DC remains unspecified. The aim of this study was to analyze size related complications following DC.

METHODS

Between 2013 and 2019, 306 patients underwent DC for elevated intracranial pressure at author´s institution. Anteroposterior and craniocaudal DC size was measured according to the postoperative CT scans. Patients were divided into two groups with (1) exposed superior sagittal sinus (SE) and (2) without superior sagittal sinus exposure (SC). DC related complications e.g. shear-bleeding at the margins of craniectomy and secondary hydrocephalus were evaluated and compared.

RESULTS

Craniectomy size according to anteroposterior diameter and surface was larger in the SE group; 14.1 ± 1 cm vs. 13.7 ± 1.2 cm, p = 0.003, resp. 222.5 ± 40 cm2 vs. 182.7 ± 36.9 cm2, p < 0.0001. The SE group had significantly lower rates of shear-bleeding: 20/176 patients; (11%), compared to patients of the SC group; 36/130 patients (27%), p = 0.0003, OR 2.9, 95% CI 1.6-5.5. There was no significant difference in the incidence of shunt-dependent hydrocephalus; 19/130 patients (14.6%) vs. 24/176 patients (13.6%), p = 0.9.

CONCLUSIONS

Complete hemispheric exposure in terms of DC with SE was associated with significantly lower levels of iatrogenic shear-bleedings compared to a SC-surgical regime. Although we did not find significant outcome difference, our findings suggest aggressive craniectomy regimes including SE to constitute the surgical treatment strategy of choice for malignant intracranial pressure.

Ultrasound Assessment of Plaque Characteristics to Predict Re-occlusion after Surgical Treatment of Internal Carotid Artery Occlusion

The purpose of this study was to explore the relationship between plaque characteristics and re-occlusion after surgical treatment of internal carotid artery occlusion (ICAO). From January 2015 to January 2021, 177 patients with ICAO underwent surgery. Eighty-five cases were included in the study, and in 13 of them, re-occlusion occurred within 6 mo after surgery treatment (13/85, 15.85%). The calcification at the base of the plaque was longer in the re-occlusion group than in the non-occlusion group (10.70 ± 4.22 mm vs. 7.15 ± 1.41 mm, p = 0.001). Multivariate regression analysis revealed that the length of calcification at the base of the plaque was an independent risk factor for postoperative re-occlusion (odds ratio [OR]: 1.414, 95% confidence interval [CI]: 1.078-1.855, p = 0.012). The cutoff value for the length of calcification at the base of the plaque predicting re-occlusion after ICAO was 8.5 mm (95% CI: 0.700-0.962, p = 0.001). The area under the receiver operating characteristic curve was 0.831. Sensitivity and specificity were 70% and 80.9%, respectively. These results indicate that pre-operative ultrasound examination of the length of calcification at the base of the plaque could predict re-occlusion after surgical treatment of ICAO.

The impact of carotid lesion calcification on outcomes of carotid artery stenting

OBJECTIVE

The impact of carotid artery lesion calcification on adverse events following carotid artery stenting is not well-studied. Few reports associated heavily calcified lesions with high risk of perioperative stroke following transfemoral carotid artery stenting (TFCAS). With the advent of transcarotid artery revascularization (TCAR), we aimed to compare the outcomes of these two procedures stratified by the degree of lesion calcification.

METHODS

Our cohort was derived from the Vascular Quality Initiative database for carotid artery stenting. Patients with missing information on the degree of carotid artery calcification were excluded. Patients were stratified into two groups: >50% (heavy) calcification and ≤50% (no/mild) calcification. The Student t test and the χ² test were used to compare patients' baseline characteristics and crude outcomes, as appropriate. Clinically relevant and statistically significantly variables on univariable analysis were added to a logistic regression model clustered by center identifier.

RESULTS

A total of 11,342 patients were included. Patients with >50% calcification were older, had more comorbidities, and more contralateral occlusion. There were more patients with prior ipsilateral carotid endarterectomy in the ≤50% calcification group. In patients who underwent TCAR, there were no significant differences between those who had >50% vs ≤50% carotid calcification in the odds of in-hospital adverse outcomes. However, in patients with heavy calcification who underwent TFCAS, there was a 50% to 60% increase in the odds of stroke (odds ratio [OR], 1.6; 95% confidence interval [CI], 1.04-2.5; P = .03), stroke/transient ischemic attack (TIA) (OR, 1.6; 95% CI, 1.1-2.3; P = .013), and stroke/death (OR, 1.5; 95% CI, 1.02-2.08; P = .039). Compared with TFCAS in patients with heavy calcification, TCAR was associated with a 40% to 90% reduction in the odds of contralateral stroke (OR, 0.13; 95% CI, 0.04-0.4; P = .001), contralateral stroke/TIA (OR, 0.3; 95% CI, 0.1-0.87; P = .024), any stroke/TIA (OR, 0.6; 95% CI, 0.38-0.91; P = .02), death (OR, 0.3; 95% CI, 0.13-0.72; P = .006), stroke/death (OR, 0.5; 95% CI, 0.32-0.8; P = .004), and stroke/death/myocardial infarction (OR, 0.58; 95% CI, 0.39-0.87; P = .008). There were no significant differences in the odds of stroke and myocardial infarction.

CONCLUSIONS

In this retrospective analysis of patients undergoing TFCAS vs TCAR in the Vascular Quality Initiative database, TCAR demonstrated favorable outcomes compared with TFCAS among patients with calcification greater than 50% of the carotid circumference. Advance burden of carotid artery calcification was associated with worse outcomes in patients undergoing TFCAS but not TCAR. These results are consistent with previously demonstrated superiority of flow reversal compared with distal embolic protection devices. Further research is needed to assess long-term outcomes and confirm the durability of TCAR in heavily calcified lesions.

Assessing the Suitability of the Carotid Bifurcation for Stenting: Anatomic and Morphologic Considerations

OBJECTIVE

Over the years where stents have been used to treat carotid lesions, a great deal has been learned about which anatomical characteristics lead to adverse outcomes. This review summarizes the anatomic and morphologic characteristics of the carotid vasculature that can help guide patient selection and clinical decision-making.

METHODS

Each of the carotid artery anatomy and lesion characteristics that are relevant to carotid stenting are described in detail. These are accompanied with evidence-based outcomes and results.

RESULTS

Data on the prevalence of carotid artery lesions that are unsuitable for stenting are summarized and the implications of these data for practice are discussed, especially as they pertain to transcarotid artery revascularization.

CONCLUSIONS

CAS can be viable option for carotid revascularization, but the lesion must be acceptable and safe for stent placement. There should be thorough assessment to rule out the presence of severe tortuosity, long-segment disease, severe calcification (circumferential or exophytic), mobile-plaque, swollen ICA sign, and carotid diameters outside the acceptable range. In carefully chosen lesions with the absence of the unfavorable characteristics described-TCAR may offer improved periprocedural success, and CAS may attain better long-term durability.

Risk Factors for Residual Stenosis After Carotid Artery Stenting

Background and purpose: Stent residual stenosis is an independent risk factor for restenosis after stenting. This study aimed to analyze the factors influencing residual stenosis after carotid artery stenting (CAS). Methods: A total of 570 patients who underwent CAS with 159 closed-loop stents (CLS) and 411 open-loop stents (OLS) from January 2013 to January 2016 were retrospectively enrolled in this study. Carotid stenosis location in the common carotid artery or in internal carotid artery, plaque size, and features (regular or irregular morphology; with or without calcification), degree of carotid artery stenosis, and stent expansion rate were detected by carotid duplex ultrasonography. Residual stenosis was defined as a stenosis rate ≥30% after CAS, as detected by digital subtraction angiography. A logistic regression analysis was used to analyze residual stenosis risk factors. Results: The overall incidence of residual stenosis was 22.8% (130/570 stents). The incidence of residual stenosis in the CLS group was higher than that in the OLS group (29.5 vs. 20.2%, χ² = 5.71, P = 0.017). The logistic regression analysis showed that CLS [odds ratio (OR), 1.933; 95% confidence interval (CI), 1.009-3.702], irregular plaques (OR, 4.237; 95% CI, 2.391-7.742), and plaques with calcification (OR, 2.370; 95% CI, 1.337-4.199) were independent risk factors for residual stenosis after CAS. In addition, a high radial expansion rate of stent was a protective factor for residual stenosis (OR, 0.171; 95% CI, 0.123-0.238). The stenosis location and stent length did not impact the occurrence of residual stenosis. After 1-year follow-up, the incidence of restenosis in the residual stenosis group was higher than that in the group without residual stenosis (13.1 vs. 2.0%, χ² = 28.05, P < 0.001). Conclusions: The findings of this study suggest that plaque morphology, echo characteristics (with calcification), and stents type influence residual stenosis.

A systemic review into carotid plaque features as predictors of restenosis after carotid endarterectomy

OBJECTIVE

Restenosis after carotid endarterectomy (CEA) limits its long-term efficacy for stroke prevention. Thus, it is of utmost importance to identify the factors that predispose a patient to restenosis after CEA. This systemic review aims to survey the current literature regarding restenosis after CEA and discuss the predictive value of carotid plaque features.

METHODS

A systemic review of studies on the predictive value of carotid plaque features for restenosis after CEA was conducted according to the PRISMA guidelines. PubMed/MEDLINE and Embase databases were searched up to March 20, 2020. Two authors independently extracted the data and assessed the risk of bias with the Quality in Prognosis Studies tool. Given the heterogeneity in the measurement of prognostic factors, types of CEA, and clinical outcomes, a qualitative synthesis was performed.

RESULTS

Twenty-one articles with a sample size that ranged from 11 to 1203 were included in this systematic review. Based on the presence of calcification in original carotid plaques, two progression patterns of restenosis were hypothesized: patients with calcified plaques may experience a temporary increase in the intima-media thickness (IMT) followed by a decrease in IMT after CEA, whereas patients with noncalcified plaques may experience a gradual increase in IMT after CEA. Accordingly, patients with a high calcium score may have a high restenosis rate within 6 months after CEA and a low restenosis rate thereafter. Thus, the late restenosis rate in patients with uniformly echogenic plaques was lower than that in patients with uniformly echolucent plaques. Pathologically, a lipid-rich, inflammatory carotid plaque is associated with a decreased risk of restenosis within 1 year after CEA, mainly owing to the relatively mild reactive intimal hyperplasia at the surgical site and active inflammation in the remaining media and adventitia. Molecular predictors for restenosis included a Mannose-binding lectin 2 genotype, preoperative C-reactive protein, serum homocysteine, apolipoprotein J, vitamin C, and telomere length of carotid plaques.

CONCLUSIONS

This review demonstrated that carotid plaque features, including imaging features, cellular composition, and molecular features, are correlated with the risk of restenosis after CEA. A comprehensive evaluation of plaque characteristics may help to stratify the risk of restenosis after CEA.

The management of carotid restenosis: a comprehensive review

Carotid artery stenosis (CS) is a major medical problem affecting approximately 10% of the general population 80 years or older and causes stroke in approximately 10% of all ischemic events. In patients with symptomatic, moderate-to-severe CS, carotid endarterectomy (CEA) and carotid angioplasty and stenting (CAS), has been used to lower the risk of stroke. In primary CS, CEA was found to be superior to best medical therapy (BMT) according to 3 large randomized controlled trials (RCT). Following CEA and CAS, restenosis remains an unsolved problem involving a large number of patients as the current treatment recommendations are not as clear as those for primary stenosis. Several studies have evaluated the risk of restenosis, reporting an incidence ranging from 5% to 22% after CEA and an in-stent restenosis (ISR) rate ranging from 2.7% to 33%. Treatment and optimal management of this disease process, however, is a matter of ongoing debate, and, given the dearth of level 1evidence for the management of these conditions, the relevant guidelines lack clarity. Moreover, the incidence rates of stroke and complications in patients with carotid stenosis are derived from studies that did not use contemporary techniques and materials. Rapidly changing guidelines, updated techniques, and materials, and modern medical treatments make actual incidence rates barely comparable to previous ones. For these reasons, RCTs are critical for determining whether these patients should be treated with more aggressive treatments additional to BMT and identifying those patients indicated for surgical or endovascular treatments. This review summarizes the current evidence and controversies concerning the risks, causes, current treatment options, and prognoses in patients with restenosis after CEA or CAS.

Profile of genetic variations in severely calcified carotid plaques by whole-exome sequencing

Background:

The precise mechanisms of carotid calcification and its clinical significance have not been established.

Methods:

We classified ten plaques from carotid endarterectomy patients into high- and low-calcified plaques based on the Agatston calcium scores. We performed whole-exome sequencing for genetic profiles with single nucleotide variations (SNVs), insertions, and deletions. Bioinformatic data mining was then conducted to disclose specific gene variations to either high- or low-calcified carotid plaques.

Results:

In the carotid plaques, G:C>A:T/C:G>T:A transitions as SNVs, insT after C/insC after A as insertions, and delA after G/delT after C as deletions were most frequently observed, but no significant difference was observed between the high- and low-calcified plaque groups in their proportion of base-pair substitution types. In the bioinformatic analysis, SNVs of ATP binding cassette subfamily C member 6 (ADCC6) were more commonly found in high-calcified plaques and SNVs of KLKB1 were more commonly found in low-calcified plaques compared to the other group. No new genetic variants related to calcification or atherosclerosis among those not registered in dbSNP was detected.

Conclusion:

Our findings clarified the features of base-pair substitutions in carotid plaques, showing no relation to calcification. However, genetic variants in ADCC6 relating to vascular calcification for high-calcified plaques, and in KLKB1 encoding kallikrein associated with vascular regulation of atherosclerosis for low-calcified plaques were more specifically extracted. These results contribute to a better understanding of the genetic basis of molecular activity and calcium formation in carotid plaques.

Correlation between risk factors of cerebrovascular disease and calcified plaque characteristics in patients with atherosclerotic severe carotid stenosis

Objectives: The aim of this study was to evaluate the relationship between the risk factors of cerebral vascular diseases (CVD) and the characteristics of calcified plaques in patients with severe carotid arteriosclerosis stenosis (SCAS).Methods: A total of 402 patients with SCAS who were treated in our hospital between January to December 2016 were included in this study. The patients were divided into calcified plaque group and non-calcified plaque group according to the ultrasonography and computerized tomography angiography (CTA) or digital subtraction angiography (DSA) imaging of SCAS-responsible plaque and the characteristics of calcified plaques evaluated by high-frequency ultrasound.Results: The patients with long-term diabetes mellitus or higher levels of fasting blood glucose were more likely to develop calcified plaques (P = 0.00 and P = 0.021, respectively). In addition, the patients with calcified plaques were mostly smokers (P = 0.016). Their smoking duration and accumulative smoking exposure were higher than those without calcified plaque (P = 0.006 and P = 0.007, respectively). The basal location of calcification (P = 0.004) and the type of patchy calcification (P = 0.00) were both easier to appear in smokers, while non-smokers were more likely to have small granular calcification (P = 0.002). Furthermore, the carotid plaque calcification with mixed-location were more frequently seen in patients with hypertension (P = 0.016). The risk factors independently associated with plaque calcification were significantly associated with smoking status, smoking age, and accumulative smoking exposure, as well as age and diabetes mellitus (all P < 0.05).Conclusion: Smoking, diabetes mellitus and age were independent risk factors for carotid plaque calcification. Smoking and hypertension were associated with specific locations and types of plaque calcification.

Analysis of Recurrent Stenosis After Carotid Endarterectomy Featuring Primary Plaque Calcification

BACKGROUND

The relationship between calcification in primary plaque and restenosis after carotid endarterectomy (CEA) has been seldom investigated.

OBJECTIVE

To clarify the relationship between characteristics of calcified carotid plaque and recurrent stenosis after CEA, as well as the disease's natural course.

METHODS

Ninety-four plaques out of 107 consecutive CEAs were retrospectively analyzed with regard to calcification, employing calcium score as well as shape, location, and other characteristics of original plaques. CEA was performed in a standard fashion with primary closure using an internal shunt. Restenosis was assessed by direct measurement of stenosis mainly using multidetector row computed tomography (CT) angiography.

RESULTS

Univariate analysis revealed that calcium score and calcification circularity score were significantly lower in more than moderate restenosis (≥50%; 422.1 ± 551.6 vs 84.2 ± 92.0, P < .001; 1.8 ± 1.3 vs 1.1 ± 0.3, P < .001, respectively). Receiver operating characteristic analysis demonstrated a calcium score of 80, which was the optimal cutoff value for restenosis over 50% (sensitivity 0.70, specificity 0.68, pseudopositive ratio 0.32, area under curve 0.71, Youden's index 0.38). Low calcium score (OR 2.88, CI 1.06-7.79, P = .04) and low calcification circularity (OR 5.72, CI 1.42-23.1, P = .01) were independent predictors for more than moderate recurrent carotid stenosis 1 year postoperatively. Cases with decreasing tendency of restenosis showed higher calcium scores than those with increasing or unchanged tendency (217.2 ± 245.3 vs 164.5 ± 155.5, P < .001). Lower calcium score cases showed lower restenosis-free survival.

CONCLUSION

Carotid plaque calcification may be inversely associated with recurrent stenosis 1 year after CEA or later. Preoperative CT assessment for less calcification will benefit restenosis patients by early prediction and close follow-up.

Calcification in original plaque and restenosis following carotid artery stenting

Background:

The relationship between calcification in primary plaque and recurrent stenosis after carotid artery stenting (CAS) is not established, but an inverse association with restenosis following carotid endarterectomy (CEA) has been suggested.

Methods:

We retrospectively analyzed 75 plaques of 109 consecutive CAS with regard to calcification, using the calcium score and shape, location, and other characteristics of original plaques together with stenting-related factors. CAS was performed in a standard fashion with an embolic protection device. Greater-than-moderate restenosis (≥50%) was assessed by peak systolic velocity (PSV) with duplex ultrasonography (≥130 cm/s, internal/common carotid or distal/proximal PSV ratio ≥2.0).

Results:

Univariate analysis revealed percentages of dyslipidemia treated with statins (P = 0.03), calcification in distal ICA (P = 0.02), and immediate residual stenosis (P = 0.02) were significantly higher in patients with greater-than-moderate restenosis, whereas calcification in carotid bulb and usage of open-cell stent were rather less frequent (P < 0.001 and P = 0.02, respectively). Multivariate logistic regression analysis showed that rarity of calcification in carotid bulb was a sole independent predictor for greater-than-moderate recurrent carotid stenosis 1 year after CAS (OR = 0.21, CI = 0.06–0.77, P = 0.02).

Conclusions:

Calcium score was not significantly related to restenosis at 1 year after CAS, as was previously found following CEA, though scarcity of calcification in carotid bulb was suggested as a predictor of in-stent restenosis. Compared to post-CEA restenosis, carotid plaque calcification may be inversely but tenuously associated with recurrent stenosis 1 year post-CAS. No other stenting factors (e.g., stent design, pre-/post-dilation, or protection devices) showed a significant association with recurrent stenosis post-CAS.

Restenosis after carotid artery stenting

As a common etiology for ischemic stroke, atherosclerotic carotid stenosis has been targeted by vascular surgery since 1950s. Compared with carotid endarterectomy, carotid angioplasty and stenting (CAS) is almost similarly efficacious and less invasive. These advantages make CAS an alternative in treating carotid stenosis. However, accumulative evidences suggested that the long-term benefit-risk ratio of CAS may be decreased or even neutralized by the complications related to in-stent restenosis (ISR). Therefore, investigating the mechanisms and identifying the influential factors of ISR are of vital importance for improving the long-term outcomes of CAS. As responses to intrinsic and extrinsic injuries, intimal hyperplasia and vascular smooth muscle cell proliferation have been regarded as the principle mechanisms for ISR development. Due to the lack of consensus-based definition and consistent follow-up protocol, the reported incidences of ISR after CAS varied widely among studies. These variations made the inter-study comparisons of ISR largely illogical. To eliminate restenosis after CAS, both surgery and endovascular procedures have been attempted with promising results. For preventing ISR, drug-eluting stents and antiplatelets have been proposed as potential solutions.

Comparison of internal shunts during carotid endarterectomy under routine shunting policy

We compared patients who underwent carotid endarterectomy (CEA) using two-way and three-way internal shunts and discussed which shunt was more appropriate and effective for surgeons. Eighty-two patients (mean 69.5 ± 6.1 years old, mean degrees of stenosis 79.6 ± 10.4%) who had undergone CEA by our routine shunting policy were examined concerning the difference of Sundt and Pruitt-Inahara (P-I) shunts in clinical use. Carotid clamping time for the P-I shunt was over 2 minutes longer than that by Sundt in either split or conventional continuous arteriotomy (p < 0.001). The proportions of cases with multiple trials of either arteriotomy or insertion of a shunt tube, cases detected more than one high-intensity spot on diffusion-weighted images of magnetic resonance imaging after CEA, and cases detected postoperative intimal flaps detected by multi-detector CT angiography showed no significant differences between the two shunt groups. The two-way Sundt shunt was quicker than the three-way P-I shunt in placement with no remarkable problems. Split arteriotomy was not useful in shortening the placement time for either Sundt or P-I shunt tubes, compared with continuous arteriotomy. A simple two-way shunt with easy handling like the Sundt shunt would be also appropriate to choose in selective shunting under the unfamiliarity of treating shunts.