Mathematical modeling in assessing the risk of restenosis after carotid endarterectomy.

Carotid endarterectomy is the main way to combat atherosclerosis of the carotid arteries, which disrupts cerebral circulation. The generally accepted marker of atherogenesis risk are hemodynamic indices associated with near-wall shear stress. The purpose of the work is to conduct a comparative analysis of hemodynamic indices in various carotid bifurcation models. The influence of a virtual change in the geometric shape of the model in order to optimize hemodynamic indices is also being studied. On the basis of computed angiography data, carotid bifurcation models are constructed, in which critical zones of hemodynamic indices are built using computational fluid dynamics. A comparative analysis of the critical zones for different classes of models is carried out. Comparison of averaged indices for critical zones between 'normal' and post-operative groups gave more than 5-x worse results for the latter. The same results for the near-bifurcation parts of the zones give a 25% better result for postoperative models. Virtual 'removal' of insignificant plaques leads to a deterioration of the indices of up to 40% in the places of the plaque's former location. The described method makes it possible to build the indices critical zones and compare them for various types of models. A technique for virtual changing the shape of a vessel (virtual surgery) is proposed. The novelty of the approach lies in the use for comparative analysis both real vessel models and hypothetical 'improved' virtual ones, as well in the proposed division of post-operative model's critical zones into subzones of different genesis.

Perioperative and Long-Term Outcomes in Patients Undergoing Synchronous Carotid Endarterectomy and Coronary Artery Bypass Grafting: A Single-Center Experience.

INTRODUCTION: Patients requiring coronary artery bypass grafting (CABG) and carotid endarterectomy (CEA) can be managed with staged (CEA before CABG), reverse staged (CABG before CEA) or synchronous treatment. This single-center retrospective study evaluated the outcomes in patients undergoing planned synchronous CEA and CABG. METHODS: Between 2000 and 2020 a total of 185 patients with symptomatic triple-vessel or left main coronary artery disease associated with 70-99% asymptomatic or 50-99% symptomatic uni- or bilateral internal carotid artery (ICA) stenosis underwent synchronous CEA and CABG at our institution. Study endpoints were defined as mortality, stroke and myocardial infarction at 30 days. Additionally, the composite endpoint of these events was investigated. RESULTS: At 30 days, mortality, stroke and myocardial infarction rates were 5.9%, 8.1% (permanent [unresolved deficit at discharge] 5.4%) and 3.8%, respectively, and the composite endpoint was reached in 13.0% of patients. Patients suffering from a stroke more frequently had a contralateral 70-99% ICA stenosis (60.0% vs. 17.3%; p < 0.001), peripheral artery disease (73.3% vs. 38.9%; p = 0.013) and prolonged cardiopulmonary bypass time (mean 119 ± 62 min vs. 84 ± 29 min; p = 0.012). Multivariate logistic regression analysis revealed the duration of cardiopulmonary bypass (odds ratio [OR] 1.024; 95% confidence interval [CI] 1.002-1.046; p = 0.034), a history of type 2 diabetes mellitus (OR 5.097; 95% CI 1.161-22.367; p = 0.031) and peripheral artery disease (OR 5.814; 95% CI 1.231-27.457; p = 0.026) as independent risk factors for reaching the composite endpoint. CONCLUSION: Patients undergoing synchronous CEA and CABG face an elevated risk of perioperative cardiovascular events, particularly an increased stroke risk in patients with symptomatic and bilateral ICA stenosis. Graphical Abstract available for this article.

Carotid Near-Occlusion: Surgical or Conservative Management? Retrospective Multicenter Study.

BACKGROUND: Carotid near-occlusion (CNO) represents an anatomical-functional condition characterized by severe (more than 90%) internal carotid artery stenosis which can lead to a distal lumen diameter greater or less than 2 mm. CNO can be divided into a less severe subgroup (without lumen full collapse: diameter >2 mm) and a more severe subgroup (with lumen full collapse: diameter <2 mm). The decision for revascularization is still highly debated in Literature. The aim of the present multicenter retrospective study is to analyze the incidence of perioperative (30 days) and follow-up complications in 2 groups of patients with or without distal internal carotid lumen full collapse. METHODS: Between January 2011 and March 2023, in 5 Vascular Surgery Units, 67 patients (49 male, 73% and 18 females, 27%) with CNO underwent carotid endarterectomy: 28 (41.7%) with lumen diameter <2 mm and 39 (58.3%) with diameter >2 mm. 19 patients were symptomatic and 48 asymptomatic. The outcomes considered for comparative analysis were: perioperative neurological and cardiac complications, carotid restenosis or occlusion at follow-up. Both groups were homogeneous in terms of risk factors, morphological features and pharmacological treatments. RESULTS: In the group with lumen <2 mm, 3 perioperative major events (10.7%) occurred (1 ischemic stroke, 1 hemorrhagic stroke, 1 myocardial infarction) and 2 (7.1%) at follow-up (average 11 ± 14.5 months; 1 asymptomatic carotid occlusion, 1 hemodynamic restenosis treated with stenting). No event was recorded in the group with lumen >2 mm. CONCLUSIONS: According to our results CNO patients show different complication risk according to the presence or not of distal lumen collapse. The later seems to play a significant role in perioperative and follow-up complication rate. These results therefore support a surgical treatment only in patients with CNO without lumen full collapse.

Clinical Significance of Carotid Endarterectomy and Carotid Artery Stenting in Older Patients Over 80.

As the average life expectancy increases, neurosurgeons are likely to encounter patients aged 80 years and above with carotid stenosis; however, whether old age affects clinical post-treatment outcomes of carotid endarterectomy (CEA) or carotid artery stenting (CAS) remains inconclusive. Thus, this study aimed to evaluate the outcomes following CEA or CAS in patients aged 80 years and above. This study included older over 80 years (n = 34) and younger patients (<80 years; n = 222) who underwent CEA or CAS between 2012 and 2022. All of them were followed up for a mean of 55 months. All-cause mortality, the incidence of vascular events, ability to perform daily activities, and nursing home admission rates were assessed. During follow-up periods, 34 patients (13.3%) died due to coronary artery disease, malignancy, and pneumonia, and the incidence was significantly higher in the elderly group than in the younger group (P = 0.03; HR, 3.01; 95% CI, 1.53-5.56). The incidence of vascular events did not differ between the older group (29.5%) and the younger group (26.9%, P = 0.58); however, the incidence was significantly higher in patients with high-intensity plaques than in those without that (P = 0.008; HR, 2.83, 95%CI, 1.27-4.87). The decline in the ability to perform daily activities and increased nursing home admission rates were high in elderly patients (P < 0.01). Although the mortality rate was higher in the elderly group, subsequent vascular events were comparable to that in the younger group. The results suggest that CEA and CAS are safe and useful treatments for carotid stenosis in older patients, especially to prevent ipsilateral ischemic stroke.

Comparison Between Conventional and Patch Carotid Endarterectomy: A Single-Center Retrospective Study.

OBJECTIVE: To compare perioperative and long-term safety and effectiveness between conventional carotid endarterectomy (cCEA) and patch carotid endarterectomy (pCEA) under current medical conditions. METHODS: Data on baseline characteristics as well as perioperative and long-term postoperative complications from patients who underwent cCEA or pCEA at the Department of Vascular Surgery, Xuanwu Hospital of Capital Medical University, from 2013 to 2022, were retrospectively collected and analyzed. RESULTS: A total of 248 CEA patients were included in our study. The majority of patients (87.3%) were male, and mean age was 63.6 ± 7.6 (range, 40-81) years; 104 patients (41.9%) underwent cCEA, while 144 (58.1%) underwent pCEA. Between the cCEA and pCEA groups, there were no significant differences in clinical baseline characteristics, occurrence of perioperative or long-term (median, 42.5 [range, 7 to 120] months) complications, and survival whether restenosis-free, asymptomatic or overall. CONCLUSIONS: In a single-center experience, conventional and patch CEA approaches appear similarly safe and effective.

Predictors of Occlusion after Carotid Stenting.

BACKGROUND: Carotid artery stent (CAS) occlusion is a rare complication not well studied. We used a national dataset to assess real world CAS experience to determine the rate of stent occlusion. The purpose of this study was to 1) Identify risk factors associated with CAS occlusion on long-term follow-up (LTFU) and 2) Determine the adjusted odds of death/transient ischemic attack (TIA)/stroke (cerebrovascular accident (CVA)) in patients with occlusion. METHODS: The national Vascular Quality Initiative CAS dataset (2016-2021) comprised the sample. The primary endpoint was occlusion on LTFU (9-21 months postoperatively as defined by the Vascular Quality Initiative LTFU dataset) with secondary endpoint examining a composite of death/TIA/CVA. Descriptive analyses used chi-square and Wilcoxon tests for categorical and continuous variables respectively. Adjustment variables were selected a priori based on clinical expertise and univariate analyses. Multivariable logistic regression was used to model the odds of occlusion and the odds of death/TIA/CVA. Generalized estimating equations accounted for center level variation. RESULTS: During the study period, 109 occlusions occurred in 12,143 cases (0.9%). On univariate analyses, symptomatic indication, prior stroke, prior neck radiation, lesion calcification (>50%), stenosis (>80%), distal embolic protection device (compared to flow reversal), balloon size, >1 stent and current smoking at time of LTFU were predictive for occlusion. Age ≥ 65, coronary artery disease (CAD), elective status, preoperative statin, preoperative and discharge P2Y12 inhibitor, use of any protection device intraoperatively and protamine were protective. On multivariable analyses, age ≥ 65, CAD, elective status and P2Y12 inhibitor on discharge were protective for occlusion, while patients with prior radiation and those taking P2Y12 inhibitor on LTFU were at increased odds. The adjusted odds of death/TIA/CVA in patients with occlusion on LTFU were 6.05; 95% confidence interval: 3.61-10.11, P < 0.0001. CONCLUSIONS: This study provides an in-depth analysis of predictors for CAS occlusion on LTFU. On univariate analyses, variables related to disease severity (urgency, degree of stenosis, nature of lesion) and intraoperative details (balloon diameter, >1 stent) were predictive for occlusion. These variables were not statistically significant after risk adjustment. On multivariable analyses, prior neck radiation was strongly predictive of occlusion. Elective status, patient age ≥ 65, CAD, and P2Y12 inhibitor upon discharge (but not on LTFU) were protective for occlusion. Additionally, patients who developed occlusion had high odds for death/TIA/CVA. These findings provide important data to guide clinical decision-making for carotid disease management, particularly identifying high-risk features for CAS occlusion. Closer postoperative follow-up and aggressive risk factor modification in these patients may be merited.

Similar long-term outcomes for venous, bovine pericardial, and polyester patches for primary carotid endarterectomy.

BACKGROUND: Currently, the type of patch used for carotid endarterectomy closure depends on the preference of the operating surgeon. Various materials are available, including autologous venous patches, bovine pericardial patches (BPP), and synthetic patches. The purpose of this study was to compare the long-term outcomes. METHODS: All patients who underwent primary carotid endarterectomy with patch angioplasty using a venous, bovine, or polyester patch between 2010 and 2020 at two high-volume medical centers were included in this retrospective analysis on largely prospectively collected data. Study endpoints included long-term ipsilateral transient ischemic attack or cerebrovascular accident, restenosis, reintervention, and all-cause mortality. Cox proportional hazard models were fitted to assess the effect of patch type to each outcome. RESULTS: In total, 1481 CEAs were performed with a follow-up of 32 (13-65) months. Venous patch was used in 309 patients (20.9%), BPP in 1000 patients (67.5%), and polyester patch in 172 patients (11.6%). A preoperative symptomatic carotid artery stenosis of >50% was observed in 91.9% (n = 284) of the patients who received a venous patch, 92.1% (n = 921) of the patients who received BPP, and 90.7% (n = 156) of the patients who received a polyester patch (p = 0.799). Only in selected patients with an asymptomatic stenosis of >70% surgery was considered. Multivariable analyses showed no significant differences between the three patch types regarding long-term outcomes after adjusting for confounders. CONCLUSIONS: In patients undergoing primary carotid endarterectomy, the use of venous, bovine pericardial, or polyester patches seems equally safe and durable in terms of comparability in long-term outcomes.

[Evolution of surgical approaches to carotid bifurcation]. / Evolyutsiya khirurgicheskikh dostupov k bifurkatsii sonnoi arterii.

Carotid endarterectomy is preferable for prevention of acute cerebrovascular accident associated with atherosclerotic lesions of internal carotid artery. Modern interest in minimizing local complications and small excisions is also actual in carotid surgery. The authors review the modern literature data on evolution of carotid arteries exposure. Cutaneous mini-incision, transverse skin incision and retrojugular approach are discussed. The authors consider the advantages and possible complications of each technique.

Association of Impedance Aggregometry-Measured Platelet Aggregation With Thromboembolic Events in Patients Who Undergo Carotid Endarterectomy: A Pilot Study.

OBJECTIVES: The aim of the current study was to assess the relationship among thrombin receptor activator peptide 6 (TRAP test), adenosine-5'-diphosphate (ADP test), arachidonic acid (ASPI test), and stroke/transient ischemic attack (TIA), using the multiple electrode aggregometry (Multiplate) in patients undergoing carotid thromboendarterectomy (CEA). DESIGN: A retrospective study. SETTING: Vascular surgery operating rooms of a university hospital. PARTICIPANTS: One hundred thirty-one out of 474 patients undergoing CEA between November 2020 and October 2022. INTERVENTIONS: None. MEASUREMENTS AND MAIN RESULTS: A preoperative blood sample of all enrolled patients was analyzed using the Multiplate analyzer. Receiver operating characteristics curves, were generated to test the ability of TRAP, ADP, and ASPI in discriminating perioperative thromboembolic stroke/TIA. A logistic LASSO regression model was used to identify factors independently associated with stroke/TIA. Eight patients experienced a perioperative stroke/TIA. Although all the platelet functional assays showed excellent predictive performance, an ADP value exceeding 72 U showed the highest specificity (87%) and sensitivity (68%) in discriminating patients who had a perioperative thromboembolic stroke/TIA, with a negative predictive value of 99% and a positive predictive value of 15%. After LASSO regression, an ADP >72 U and the need for a shunt during CEA were the only 2 variables independently associated with perioperative stroke/TIA. CONCLUSION: Because the ADP test was independently associated with perioperative stroke/TIA, the assessment of platelet reactivity using Multiplate may offer potential utility in monitoring patients undergoing CEA.

Nasal Intubation is not Associated with "Smoother" Emergence from General Anesthesia for Carotid Endarterectomy: A Case-Cohort Study.

BACKGROUND: Postoperative hematoma after carotid endarterectomy (CEA) is a devastating complication and may be more likely in patients with uncontrolled hypertension and coughing on emergence from anesthesia. We sought to determine if intubation with a nasal endotracheal tube (ETT)-instead of an oral ETT-is associated with "smoother" (i.e., less hemodynamic instability) emergence from general anesthesia for CEA. METHODS: Patients receiving CEA between December 2015 and September 2021 at a single tertiary academic medical center were included. We examined the electronic anesthesia records for 323 patients who underwent CEA during the 6-year study period and recorded consecutive systolic blood pressure (SBP) values during the 10 minutes before extubation as a surrogate for "smoothness" of the emergence. RESULTS: Intubation with a nasal ETT, when compared with intubation with an oral ETT, was not associated with any difference in maximum, minimum, average, median, or standard deviation of serial SBP values in the 10 minutes before extubation. The average SBP on emergence for patients with an oral ETT was 141 mm Hg and with a nasal ETT was 144 mm Hg (P = 0.562). The maximum SBP for patients with oral and nasal ETTs were 170 mm Hg and 174 mm Hg, respectively (P = 0.491). There were also no differences in the qualitative "smoothness" of emergence or in the percentage of patients who required an intravenous dose of 1 or more antihypertensive medications. The incidence of postoperative complications was similar between the 2 groups. CONCLUSIONS: When SBP is used as a surrogate for smoothness of emergence from general anesthesia for CEA, intubation with a nasal ETT was not associated with better hemodynamic stability compared to intubation with an oral ETT.

Utility of the triglyceride-glucose index for predicting restenosis following revascularization surgery for extracranial carotid artery stenosis: A retrospective cohort study.

BACKGROUND: Carotid endarterectomy (CEA) and carotid artery stenting (CAS) are effective interventions for treating extracranial carotid artery stenosis (ECAS), but long-term prognosis is limited by postoperative restenosis. Carotid restenosis is defined as carotid stenosis >50% by various examination methods in patients after carotid revascularization. This retrospective cohort study examined the value of the triglyceride-glucose (TyG) index for predicting vascular restenosis after carotid revascularization. METHODS: A total of 830 patients receiving CEA (408 cases, 49.2%) or CAS (422 cases, 50.8%) were included in this study. Patients were stratified into three subgroups according to TyG index tertile (high, intermediate, and low), and predictive value for restenosis was evaluated by constructing multivariate Cox proportional hazard regression models. RESULTS: Incidence of postoperative restenosis was significantly greater among patients with a high TyG index according to univariate analysis. Kaplan-Meier survival curve analysis revealed a progressive increase in restenosis prevalence with rising TyG index. Multivariate Cox regression models also identified TyG index as an independent predictor of restenosis, while receiver operating characteristic (ROC) curve analysis showed that TyG index predicted restenosis with moderate sensitivity (57.24%) and specificity (67.99%) (AUC: 0.619, 95% CI 0.585-0.652, z-statistic=4.745, p<0.001). Addition of the TyG index to an established risk factor model incrementally improved restenosis prediction (AUC: 0.684 (0.651-0.715) vs 0.661 (0.628-0.694), z-statistic =2.027, p = 0.043) with statistical differences. CONCLUSION: The TyG index is positively correlated with vascular restenosis risk after revascularization, which can be used for incremental prediction and has certain predictive value.

Outcomes following carotid revascularization for stroke stratified by Modified Rankin Scale and time of intervention.

OBJECTIVES: The relationship between baseline Modified Rankin Scale (mRS) in patients with prior stroke and optimal timing of carotid revascularization is unclear. Therefore, we evaluated the timing of transfemoral carotid artery stenting (tfCAS), transcarotid artery revascularization (TCAR), and carotid endarterectomy (CEA) after prior stroke, stratified by preoperative mRS. METHODS: We identified patients with recent stroke who underwent tfCAS, TCAR, or CEA between 2012 and 2021. Patients were stratified by preoperative mRS (0-1, 2, 3-4, or 5) and days from symptom onset to intervention (time to intervention; ≤2 days, 3-14 days, 15-90 days, and 91-180 days). First, we performed univariate analyses comparing in-hospital outcomes between separate mRS or time-to-intervention cohorts for all carotid intervention methods. Afterward, multivariable logistic regression was used to adjust for demographics and comorbidities across groups, and outcomes between the various intervention methods were compared. Primary outcome was the in-hospital stroke/death rate. RESULTS: We identified 4260 patients who underwent tfCAS, 3130 patients who underwent TCAR, and 20,012 patients who underwent CEA. Patients were most likely to have minimal disability (mRS, 0-1 [61%]) and least likely to have severe disability (mRS, 5 [1.5%]). Patients most often underwent revascularization in 3 to 14 days (45%). Across all intervention methods, increasing preoperative mRS was associated with higher procedural in-hospital stroke/death (all P < .03), whereas increasing time to intervention was associated with lower stroke/death rates (all P < .01). After adjustment for demographics and comorbidities, undergoing tfCAS was associated with higher stroke/death compared with undergoing CEA (adjusted odds ratio, 1.6; 95% confidence interval, 1.3-1.9; P < .01) or undergoing TCAR (adjusted odds ratio, 1.3; 95% confidence interval, 1.0-1.8; P = .03). CONCLUSIONS: In patients with preoperative stroke, optimal timing for carotid revascularization varies with stroke severity. Increasing preoperative mRS was associated with higher procedural in-hospital stroke/death rates, whereas increasing time to-intervention was associated with lower stroke/death rates. Overall, patients undergoing CEA were associated with lower in-hospital stroke/deaths. To determine benefit for delayed intervention, these results should be weighed against the risk of recurrent stroke during the interval before intervention.

Local and systemic factors associated with quantitative stiffness of carotid plaque.

PURPOSE: Plaque stiffness in carotid artery stenosis is a clinically important factor involved in the development of stroke and surgical complications. The purpose of this study was to clarify which local and systemic factors are associated with the quantitatively measured stiffness of plaque. METHODS: The subjects were 104 consecutive patients who underwent carotid endarterectomy at our institution. To measure quantitative stiffness of plaque, we used an industrial hard meter in the operating room within 1 h after removal of plaque. Local factors related to carotid plaque hardness were evaluated, including maximum intima-media thickness (max IMT), degree of stenosis using the European Carotid Surgery Trial (ECST), presence of ulceration or calcification, and echo brightness on preoperative carotid ultrasound. The degree of stenosis was also evaluated using the North American Symptomatic Carotid Endarterectomy Trial method in digital subtraction angiography. Age, sex, and presence or absence of hypertension, diabetes, and dyslipidemia (low-density lipoprotein cholesterol and triglyceride [TG] levels) served as systemic factors and were compared with the quantitative stiffness of carotid plaque. RESULTS: In multivariate analysis, ECST stenosis degree, calcification, and IMT max as local factors affected plaque stiffness. As a systemic factor, plaque stiffness was statistically significantly negatively correlated with TG values in multivariate analysis (p < 0.05). CONCLUSION: The quantitative stiffness of the plaque was negatively correlated with TG levels as a systemic factor in addition to local factors. This might suggest that reducing high TG levels is associated with plaque stabilization.

Duplex ultrasound and cross-sectional imaging in carotid artery occlusion diagnosis.

OBJECTIVE: Investigations into imaging modalities in the diagnosis of extracranial carotid artery occlusion (CAO) have raised questions about the inter-modality comparability of duplex ultrasound (DUS) and cross-sectional imaging (CSI). This study examines the relationship between DUS and CSI diagnoses of extracranial CAO. METHODS: This single-institution retrospective analysis studied patients with CAO diagnosed by DUS from 2010 to 2021. Patients were identified in our office-based accredited vascular laboratory database. Imaging and clinical data was obtained via our institutional electronic medical record. Primary outcome was discrepancy between DUS and CSI modalities. Secondary outcomes included incidence of stroke and intervention subsequent to CAO diagnosis. RESULTS: Of our 140-patient cohort, 95 patients (67.9%) had DUS follow-up (mean, 42.7 ± 31.3 months). At index duplex, 68.0% of individuals (n = 51) were asymptomatic. Seventy-five patients (53.6%) had CSI of the carotids after DUS CAO diagnosis; 18 (24%) underwent magnetic resonance imaging and 57 (76%) underwent computed tomography. Indications for CSI included follow-up of DUS findings of carotid stenosis/occlusion (44%), stroke/transient ischemic attack (16%), other symptoms (12%), preoperative evaluation (2.7%), unrelated pathology follow-up (9.3%), and outside institution imaging with unavailable indications (16%). When comparing patients with CSI and those without, there were no differences with regard to symptoms at diagnosis, prior neck interventions, or hypertension. There was a significant difference between cross-sectionally imaged and non-imaged patients in anti-hypertensive medications (72% vs 53.8%; P = .04). Despite initial DUS diagnoses of carotid occlusion, 10 patients (13.3%) ultimately had CSI indicating patent carotids. Four of these 10 patients had stenoses of ∼99% (with 1 string sign), four of 70% to 99%, one of 50% to 69%, and one of less than 50% on CSI. The majority of patients (70%) had CSI within 1 month of the index ultrasound. There were no significant relationships between imaging discrepancies and body mass index, heart failure, upper body edema, carotid artery calcification, and neck hardware. Eight individuals (10.7%) underwent ipsilateral revascularization; 62.5% (n = 5) were carotid endarterectomy procedures, and the remaining three procedures were a transcervical carotid revascularization, subclavian to internal carotid artery bypass, and transfemoral carotid artery stenting. Eight patients (10.7%) underwent contralateral revascularization, with the same distribution of procedures as those ipsilateral to occlusions. Two of the 10 patients with discrepancies underwent carotid endarterectomy, and one underwent carotid stenting. CONCLUSIONS: In our experience, duplex diagnosis of CAO is associated with a greater than 10% discordance when compared with CSI. These patients may benefit from closer surveillance as well as confirmatory computed tomography or magnetic resonance angiography. Further work is needed to determine the optimal diagnostic modality for CAO.