Disturbed flow in the juxta-anastomotic area of an arteriovenous fistula correlates with endothelial loss, acute thrombus formation, and neointimal hyperplasia.

Clinical failure of arteriovenous neointimal hyperplasia (NIH) fistulae (AVF) is frequently due to juxta-anastomotic NIH (JANIH). Although the mouse AVF model recapitulates human AVF maturation, previous studies focused on the outflow vein distal to the anastomosis. We hypothesized that the juxta-anastomotic area (JAA) has increased NIH compared with the outflow vein. AVF was created in C57BL/6 mice without or with chronic kidney disease (CKD). Temporal and spatial changes of the JAA were examined using histology and immunofluorescence. Computational techniques were used to model the AVF. RNA-seq and bioinformatic analyses were performed to compare the JAA with the outflow vein. The jugular vein to carotid artery AVF model was created in Wistar rats. The neointima in the JAA shows increased volume compared with the outflow vein. Computational modeling shows an increased volume of disturbed flow at the JAA compared with the outflow vein. Endothelial cells are immediately lost from the wall contralateral to the fistula exit, followed by thrombus formation and JANIH. Gene Ontology (GO) enrichment analysis of the 1,862 differentially expressed genes (DEG) between the JANIH and the outflow vein identified 525 overexpressed genes. The rat jugular vein to carotid artery AVF showed changes similar to the mouse AVF. Disturbed flow through the JAA correlates with rapid endothelial cell loss, thrombus formation, and JANIH; late endothelialization of the JAA channel correlates with late AVF patency. Early thrombus formation in the JAA may influence the later development of JANIH.NEW & NOTEWORTHY Disturbed flow and focal endothelial cell loss in the juxta-anastomotic area of the mouse AVF colocalizes with acute thrombus formation followed by late neointimal hyperplasia. Differential flow patterns between the juxta-anastomotic area and the outflow vein correlate with differential expression of genes regulating coagulation, proliferation, collagen metabolism, and the immune response. The rat jugular vein to carotid artery AVF model shows changes similar to the mouse AVF model.

Evaluation of microembolic signals on carotid ultrasound during pulmonary vein isolation with high-power short-duration and cryoballoon ablations: When and where do bubble and solid emboli arise?

INTRODUCTION: The underlying risks of asymptomatic embolization during high-power short-duration (HPSD) ablation for atrial fibrillation remain unclear. We aimed to evaluate microembolic signals (MESs) during HPSD ablation with power settings of 50 and 90 W in comparison with those during cryoballoon (CB) ablation using a novel carotid ultrasound-Doppler system that classifies solid and air bubble signals using real-time monitoring. METHODS AND RESULTS: Forty-seven patients underwent HPSD ablation using radiofrequency (RF), and 13 underwent CB ablation. MESs were evaluated using a novel pastable soft ultrasound probe equipped with a carotid ultrasound during pulmonary vein isolation. We compared the detailed MESs and their timing between RF and CB ablations. The number of MESs and solid signals were significantly higher in the RF group than in CB group (209 ± 229 vs. 79 ± 32, p = .047, and 83 ± 89 vs. 28 ± 17, p = .032, respectively). In RF ablation, the number of MESs, solid, and bubble signals per ablation point, or per second, was significantly higher at 90 W than at 50 W ablation. The MESs, solid, and bubble signals were detected more frequently in the bottom and anterior walls of the left pulmonary vein (LPV) ablation. In contrast, many MESs were observed before the first CB application and decreased chronologically as the procedure progressed. Signals were more prevalent during the CB interval rather than during the freezing time. Among the 28 patients, 4 exhibited a high-intensity area on postbrain magnetic resonance imaging (MRI). The MRI-positive group showed a trend of larger signal sizes than did the MRI-negative group. CONCLUSION: The number of MESs was higher in the HPSD RF group than in the CB group, with this risk being more pronounced in the 90 W ablation group. The primary detection site was the anterior wall of the LPV in RF and the first interval in CB ablation.

Accelerated Measurement of Carotid Plaque Volume Using Artificial Intelligence Enhanced 3D Ultrasound.

BACKGROUND: Carotid plaque volume (CPV) can be measured by 3D ultrasound and may be a better predictor of stroke than stenosis, but analysis time limits clinical utility. This study tested the accuracy, reproducibility, and time saved of using an artificial intelligence (AI) derived semiautomatic software to measure CPV ("auto-CPV"). METHODS: Three-dimensional (3D) ultrasound images for 121 individuals were analyzed by 2 blinded operators to measure auto-CPV. Corresponding endarterectomy specimen volumes were calculated by the validated saline suspension technique. Inter-rater and intrarater agreement plus accuracy compared with the volume of the endarterectomized plaque were calculated. Measurement times were compared with previous manual CPV measurement. RESULTS: The mean difference between auto-CPV and surgical volume was small at (±s.d.) [95% confidence interval [CI]] 0.06 (0.24) [-0.41 to 0.54] cm3. The intraclass correlation (ICC) was strong at 0.91; 95% CI 0.86-0.94. Interobserver and intraobserver error was low with mean difference (±s.d.) [95%CI] 0.01 (0.26) [-0.5 to 0.5] cm3 and 0.03 (0.19) [-0.35 to 0.40] cm3 respectively. Both showed excellent ICC with narrow confidence intervals, ICC = 0.90; 95% CI (0.85-0.94) and ICC = 0.95; 95% CI (0.92-0.96). Auto-CPV measurement took 43% the time of manual planimetry; median (IQR) 05:39 (01:58) minutes compared to 13:05 (04:15) minutes, Wilcoxon rank-sum test, P < 0.01. CONCLUSIONS: Auto-CPV assessment is accurate, reproducible, and significantly faster than manual planimetry. Improved feasibility means that the utility of CPV can be assessed in large population studies to stratify risk in asymptomatic carotid disease or assess response to medical treatment.

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.

Establishment and preliminary application of personalized three-dimensional reconstruction of thyroid gland with automatic detection of thyroid nodules based on ultrasound videos.

PURPOSE: A well display of the spatial location of thyroid nodules in the thyroid is important for surgical path planning and surgeon-patient communication. The aim of this study was to establish a three-dimensional (3D) reconstruction method of the thyroid gland, thyroid nodule, and carotid artery with automatic detection based on two-dimensional (2D) ultrasound videos, and to evaluate its clinical value. METHODS: Ultrasound videos, including the thyroid gland with nodule, isthmus of thyroid gland, and ipsilateral carotid artery, were recorded. BC-UNet, MTN-Net, and RDPA-U-Net network models were innovatively employed for segmentation of the thyroid glands, the thyroid nodules, and the carotid artery respectively. Marching Cubes algorithm was used for reconstruction, while Laplacian smoothing algorithm was employed to smooth the 3D model surface. Using this model, 20 patients and 15 surgeons completed surveys on the effectiveness of this model for the pre-surgery demonstration of nodule location as well as surgeon-patient communication. RESULTS: The thyroid gland with nodule, isthmus of gland, and carotid artery were reconstructed and displayed. With the 3D model, the understanding of the spatial location of thyroid nodules improved in all three surgeon groups, eliminating the influence of professional levels. In the patient survey, the patients' understanding of the thyroid nodule location and procedure for surgery were significantly improved. In addition, with the 3D model, the time for doctors to explain to patients was significantly reduced (16.75  vs. 8.85 min, p = 0.001). CONCLUSION: To our knowledge, this is the first report of constructing a 3D thyroid model using a deep learning technique for personalized thyroid segmentation based on 2D ultrasound videos. The preliminary clinical application showed that it was conducive to the comprehension of the location of thyroid nodules for surgeons and patients, with significant improvement on the efficiency of surgeon-patient communication.

Assessment of Plaque Characteristics by Contrast-Enhanced Ultrasound and Stent Restenosis following Carotid Artery Stenting: A Retrospective Study.

Background and objective: carotid artery stenosis contributes significantly to ischemic strokes, with management options including carotid endarterectomy (CEA) and carotid artery stenting (CAS) ischemic stroke risk can be reduced. Controversies persist regarding their efficacy and factors influencing complications, and understanding the relationship between atherosclerotic plaque characteristics and stent restenosis after CAS is crucial. Methods: we conducted a retrospective study involving 221 patients who underwent CAS for symptomatic or asymptomatic carotid artery stenosis. Comprehensive assessments of plaque morphology were performed using contrast-enhanced ultrasound (CEUS) before CAS. Patient demographics, including smoking status and diabetes, were also recorded. Stent restenosis was diagnosed using various imaging modalities, including ultrasound, angiography, and digital subtraction angiography (DSA). Results: plaque analysis using CEUS revealed a significant association between plaque grade and restenosis incidence (p < 0.001), particularly with grade 0 (11.1%) and grade 2 plaques (66.7%). Smoking was notably associated with plaque vascularization and restenosis (p < 0.001), while diabetes did not significantly impact plaque characteristics or restenosis risk (p > 0.05). The mean duration of restenosis was 17.67 months. Stenting was the most frequent treatment modality for restenosis (70.6%). However, no significant relationship was found between restenosis type and plaque morphology (p = 0.268). Furthermore, while no clear relationship was observed between plaque morphology and the type of restenosis, our findings underscored the importance of plaque characterization in predicting post-CAS outcomes. Conclusions: this study highlights the utility of CEUS in predicting stent restenosis following CAS. There was a significant association between stent restenosis within 12-24 months after the carotid stenting procedure and an elevated grade of plaque vascularization. Moreover, one of the main factors possibly determining the grade of plaque vascularization was smoking. Further research is warranted to elucidate the underlying mechanisms and refine risk stratification in this patient population.

When Will We Have What We Need to Advise Patients How to Manage Their Carotid Stenosis?: Lessons From SPACE-2.

The recently published SPACE-2 trial (Stent-Supported Percutaneous Angioplasty of the Carotid Artery Versus Endarterectomy-2) compared 3 treatments to prevent stroke in patients with asymptomatic carotid stenosis ≥70%: (1) carotid endarterectomy plus best medical treatment (BMT), (2) transfemoral carotid artery stenting plus BMT, or (3) BMT alone. Because of low enrollment, the findings of similar safety and efficacy for carotid endarterectomy, carotid artery stenting, or BMT alone were inconclusive. Publication of the CREST (Carotid Revascularization and Medical Management for Asymptomatic Carotid Stenosis Trial)-2 results should provide level A evidence that has been lacking for 2 to 3 decades, to guide treatment of asymptomatic patients with severe carotid stenosis. For symptomatic patients with ≥70% stenosis, no trials are underway to update the degree of benefit reported for carotid endarterectomy by NASCET (North American Carotid Endarterectomy Trial) and ECST (European Carotid Surgery Trial), published in 1991. Subsequently, the use of cigarettes has plummeted, and major improvements in medical treatments and in carotid revascularization have emerged. These advances have coincided with abrupt decline in the clinical end points necessary for treatment comparisons in procedural trials. One of the advances in the invasive management of carotid disease has been transcarotid artery revascularization, already with limited approval by the US Food and Drug Administration. Establishing safety and efficacy of transcarotid artery revascularization compared with carotid endarterectomy, carotid artery stenting, or BMT alone may be challenging because of enrollment, regulatory, and funding barriers to design and complete an adequately powered randomized trial.

Impact of Carotid Stent Design on Embolic Filter Debris Load During Carotid Artery Stenting.

BACKGROUND: The carotid stent design may influence the risk of embolization during carotid artery stenting. The aim of the study was to assess this risk by comparing the quantity of embolized material captured by filters during carotid artery stenting, using different stent designs. METHODS: We conducted a single-center retrospective study of patients undergoing carotid artery stenting for asymptomatic carotid stenosis >70% (2010-2022) in a tertiary academic hospital (Padua University Hospital, Italy). Carotid stents were classified according to their design as open-cell (OCS), closed-cell (CCS), or micromesh stents (MMS). A distal filter protection was used in all patients, and the amount of captured embolized particles was semiautomatically analyzed using a dedicated software (Image-Pro Plus, Media Cybernetics). Primary end point was embolic filter debris (EFD) load, defined as the ratio of the filter area covered by particulate material to the total filter area. Secondary end points were 30 days major stroke and death. RESULTS: Four-hundred-eighty-one carotid artery stentings were included; 171 (35%) using an OCS, 68 (14%) a CCS, and 242 (50%) a MMS. Thirty-days mortality was 0.2% (n=1) and major stroke rate was 0.2% (P=0.987). Filters of patients receiving MMS were more likely to be free from embolized material (OCS, 30%; CCS, 13%; MMS, 41%; P<0.001) and had a lower EFD load (OCS, 9.1±14.5%; CCS, 7.9±14.0%; MMS, 5.0±9.1%; P<0.001) compared with other stent designs. After stratification by plaque characteristics, MMS had a lower EFD load in cases of hypoechogenic plaque (OCS, 13.4±9.9%; CCS, 10.9±8.7%; MMS, 6.5±13.1%; P<0.001), plaque length>15 mm (OC, 10.2±15.3; CC, 8.6±12.4; MM, 8.2±13.6; P<0.001), and preoperative ipsilateral asymptomatic ischemic cerebral lesion (OCS, 12.9±16.8%; CCS, 8.7±19.5%; MMS, 5.4±9.7%; P<0.001). After multivariate linear regression, use of MMS was associated with lower EFD load (P=0.038). CONCLUSIONS: The use of MMS seems to be associated with a lower embolization rate and EFD load, especially in hypoechogenic and long plaques and in patients with a preoperative evidence of asymptomatic ischemic cerebral lesion.

Impact of residual stenosis on clinical outcomes when performing carotid artery stenting without postdilation.

OBJECTIVE: Many centers consider postdilation if the final angiography after carotid artery stenting (CAS) shows residual stenosis of >30% to 40%. Postdilation has been demonstrated to potentially increase the risk of developing neurologic events. This study aimed to investigate the safety of CAS without postdilation regardless of the degree of residual stenosis. METHODS: We retrospectively investigated 191 patients who underwent transfemoral CAS without postdilation intendedly. All cases underwent mild predilation and self-expanding stent implantation. We divided the patients into a residual stenosis of ≥40% group (n = 69 [36.1%]) and a residual stenosis of <40% group (n = 122 [63.9%]) according to their final angiography. We compared the procedural (within 30 days after CAS) and nonprocedural (afterward) adverse cardiovascular events and in-stent restenosis between the two groups. We also investigated the incidence of perioperative hemodynamic depression between the groups and the changes in residual stenosis over the follow-up time. RESULTS: Patients in the residual stenosis of ≥40% group had a higher preoperative stenosis rate and a greater proportion of severely calcified lesions than those in the <40% group. There was one procedural cardiac death (0.5%), five strokes (2.6%), and four myocardial infarctions (2.1%). A total of 2.9% had stroke or death procedurally in the residual stenosis of ≥40% group and 3.2% in the residual stenosis of <40% group (P > .950). The median nonprocedural follow-up time was 22 months, with a total of six deaths and four strokes. The cumulative 2-year death or stroke rate was 6.2%, with 5.9% in the residual stenosis of ≥40% group versus 6.7% in the residual stenosis of <40% group (P = .507). There were two cases of in-stent restenosis in the residual stenosis of ≥40% group and three in the residual stenosis of <40% group (P = .927). The difference in the peak systolic velocity of the target lesion between groups at 3 months after CAS was no longer present, and residual stenosis stabilized at 10% to 20% at 6 months in both groups. The patients showed an association between increasing hemodynamic depression incidence and residual stenosis in a significantly graded response (P = .021). CONCLUSIONS: Residual stenosis after carotid stenting without postdilation is not associated with a risk of postoperative adverse events. This study provides evidence for the feasibility of a no postdilation strategy for CAS.

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.

Prediction of new cerebral ischemic lesion after carotid artery stenting: a high-resolution vessel wall MRI-based radiomics analysis.

OBJECTIVES: Carotid artery stenting (CAS) is an established treatment for local stenosis. The most common complication is new ipsilateral ischemic lesions (NIILs). This study aimed to develop models considering lesion morphological and compositional features, and radiomics to predict NIILs. MATERIALS AND METHODS: One hundred and forty-six patients who underwent brain MRI and high-resolution vessel wall MR imaging (hrVWI) before and after CAS were retrospectively recruited. Lumen and outer wall boundaries were segmented on hrVWI as well as atherosclerotic components. A traditional model was constructed with patient clinical information, and lesion morphological and compositional features. Least absolute shrinkage and selection operator algorithm was performed to determine key radiomics features for reconstructing a radiomics model. The model in predicting NIILs was trained and its performance was tested. RESULTS: Sixty-one patients were NIIL-positive and eighty-five negative. Volume percentage of intraplaque hemorrhage (IPH) and patients' clinical presentation (symptomatic/asymptomatic) were risk factors of NIILs. The traditional model considering these two features achieved an area under the curve (AUC) of 0.778 and 0.777 in the training and test cohorts, respectively. Twenty-two key radiomics features were identified and the model based on these features achieved an AUC of 0.885 and 0.801 in the two cohorts. The AUCs of the combined model considering IPH volume percentage, clinical presentation, and radiomics features were 0.893 and 0.842 in the training and test cohort respectively. CONCLUSIONS: Compared with traditional features (clinical and compositional features), the combination of traditional and radiomics features improved the power in predicting NIILs after CAS. KEY POINTS: • Volume percentage of IPH and symptomatic events were independent risk factors of new ipsilateral ischemic lesions (NIILs). • Radiomics features derived from carotid artery high-resolution vessel wall imaging had great potential in predicting NIILs after CAS. • The combination model with radiomics and traditional features further improved the diagnostic performance than traditional features alone.

A Systematic Review of Clinical Outcomes After Carotid Artery Ligation Versus Carotid Artery Reconstruction Following Venoarterial Extracorporeal Membrane Oxygenation in Infants and Children.

INTRODUCTION: In pediatric and neonatal populations, the carotid artery is commonly cannulated for venoarterial (VA) extracorporeal membrane oxygenation (ECMO). The decision to ligate (carotid artery ligation [CAL]) versus reconstruct (carotid artery reconstruction [CAR]) the artery at decannulation remains controversial as long-term neurologic outcomes remain unknown. The objective of this study was to summarize current literature on clinical outcomes following CAL and CAR after Venoarterial Extracorporeal Membrane Oxygenation (VA-ECMO). METHODS: PubMed (MEDLINE), Embase, Web of Science, and Cochrane databases were searched using keywords from January 1950 to October 2020. Studies examining clinical outcomes following CAL and CAR for VA-ECMO in patients <18 y of age were included. Prospective and retrospective cohort studies, case series, case-control studies, and case reports were included. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines were performed independently by two reviewers. Assessment of risk of bias was performed. RESULTS: Eighty studies were included and classified into four categories: noncomparative clinical outcomes after CAL (n = 23, 28.8%), noncomparative clinical outcomes after CAR (n = 12, 15.0%), comparative clinical outcomes after CAL and/or CAR (n = 28, 35.0%), and case reports of clinical outcomes after CAL and/or CAR (n = 17, 21.3%). Follow-up ranged from 0 to 11 y. CAR patency rates ranged from 44 to 100%. There was no substantial evidence supporting an association between CAL versus CAR and short-term neurologic outcomes. CONCLUSIONS: Studies evaluating outcomes after CAL versus CAR for VA-ECMO are heterogeneous with limited generalizability. Further studies are needed to evaluate long-term consequences of CAL versus CAR, especially as the first survivors of pediatric/neonatal ECMO approach an age of increased risk of carotid stenosis and stroke.

Outcomes Following Carotid Endarterectomy and Carotid Artery Stenting in Patients with Carotid Artery Stenosis: A Retrospective Study from a Single Center in South Korea.

BACKGROUND Previous randomized controlled trials and meta-analyses comparing carotid endarterectomy (CEA) and carotid artery stenting (CAS) included a large number of patients, but the diagnosis, treatment selection, and performance were heterogeneous. This retrospective study from a single center in South Korea aimed to evaluate outcomes following CEA and CAS in patients with carotid artery stenosis. MATERIAL AND METHODS A retrospective analysis was performed using the data of patients who underwent carotid revascularization between September 2016 and June 2021 at a single institution. The primary outcomes were stroke, myocardial infarction (MI), and death during the periprocedural period. RESULTS We enrolled a total of 61 (44 symptomatic and 17 asymptomatic) patients who underwent CEA or CAS. Among them, 36 (59%) underwent CEA and 25 (41%) underwent CAS. Statistically significant differences were found between the groups in degree of carotid stenosis (CEA: 87.0±9.1, CAS: 80.5±9.3, P=0.007). All patients with confirmed plaque ulceration before carotid revascularization underwent CEA. Two (3.3%) periprocedural strokes occurred, 1 in each group, on the ipsilateral side. There were no significant differences between CEA and CAS in the event-free survival rate for stroke during the follow-up (log-rank test=0.806). CONCLUSIONS Favorable outcomes in terms of periprocedural stroke were observed. We found no significant difference between the 2 carotid revascularization techniques in the incidence of periprocedural stroke in symptomatic and asymptomatic patients. To confirm our findings, further studies involving a larger number of patients and continuous follow-up are necessary.

A Retrospective Review of Bovine Artery Graft Patency: A Single-Site Study.

BACKGROUND: The hemodialysis-dependent population is increasing in the United States. Dialysis access complications are a significant source of morbidity and mortality for patients with end-stage renal disease. A surgically created autogenous arteriovenous fistula has been the gold standard for dialysis access. However, for patients who are not candidates for arteriovenous fistula, arteriovenous grafts using various conduits have widely been used. In this study, we report the outcomes of bovine carotid artery (BCA) grafts for dialysis access at a single institution and compare these results to those for polytetrafluoroethylene (PTFE) grafts. METHODS: A single-institution, retrospective review of all patients undergoing surgical placement of a bovine carotid artery graft for dialysis access from 2017-2018 was performed under an institutional review board-approved protocol. The primary, primary-assisted, and secondary patency were calculated for the whole cohort and results determined based on gender, body mass index (BMI), and indication for use. Comparison was performed to PTFE grafts at same institution from 2013 to 2016. RESULTS: One hundred and twenty two patients were included in this study. Seventy four patients had a BCA graft placed while 48 had a PTFE graft placed. . The mean age was 59.7 ± 13.5 years in the BCA group, 55.8 ± 14.5 in the PTFE group, and the mean BMI was 29.8 ± 9.2 kg/m2 in the BCA group and 28.1 ± 9.7 in the PTFE group. Comparison of the comorbidities present in BCA/PTFE groups included hypertension (92%/100%), diabetes (57%/54%), congestive heart failure (28%/10%), lupus (5%/7%), and chronic obstructive pulmonary disease (4%/8%). The various configurations were reviewed (BCA/PTFE): interposition/access salvage (40.5%/13%), axillary-axillary (18.9%, 7%), brachial-basilic (5.4%, 6%), brachial-brachial (4.1%, 4%), brachial-cephalic (1.4%, 0%), axillary-brachial (1.4%, 0%), brachial-axillary (23%, 62%), and femoral-femoral (5.4%, 6%). Overall, 12-month primary patency was 50% in the BCA group and 18% in the PTFE group (P = 0.001). Twelve-month primary-assisted patency was 66% in the BCA group and 37% in the PTFE group (P = 0.003). Twelve-month secondary patency was 81% in the BCA group and 36% in the PTFE group (P = 0.07). When comparing BCA graft survival probability among male and female gender, males had better primary-assisted patency (P = 0.042). Secondary patency among the 2 genders was similar. There was no statistically significant difference in primary, primary-assisted, and secondary patency of BCA grafts between different BMI groups and indication for use. The average patency of a bovine graft was 17.8 ± 8 months. Sixty one percent of the BCA grafts needed intervention with 24% needing multiple interventions. There was an average of 7 ± 5 months to first intervention. The infection rate was 8.1% in the BCA group and 10.4% in the PTFE group with no statistical difference. CONCLUSIONS: Primary and primary-assisted patency rates at 12 months in our study were higher than those for PTFE at our institution. There was higher primary-assisted patency of BCA grafts among males at 12 months compared to PTFE. Obesity and indication for BCA graft use did not appear to affect patency in our population.

Infective Native Extracranial Carotid Artery Aneurysms: A Systematic Review.

BACKGROUND: Infective native extracranial carotid artery aneurysms are rare, and their management is variable due to a lack of evidence assessing outcomes. METHODS: We performed a systematic literature review following PRISMA guidelines to identify all reported cases of infective native extracranial carotid artery aneurysms between January 1970 and March 2021. RESULTS: This study identified 193 infective native aneurysms of the extracranial carotid artery from 154 sources. Patients were predominantly male (71.4%), and age ranged from 6 months to 89 years old. The most common presenting features were a neck mass and fever, but also included hemorrhage, respiratory distress, and neurological symptoms. Most aneurysms were located in the internal carotid artery (47.4%). Staphylococcus (23.3%) was the most commonly identified causative pathogen, followed by Mycobacterium tuberculosis (20.9%). Most appeared to become infected by direct local spread. Treatment strategies involved open surgical methods in 101 cases and an endovascular approach in 41 cases. In 4 cases, a hybrid method involving concurrent endovascular and open surgical management was undertaken. In 5 cases, there was antibiotic treatment alone. In the open surgery-treated group, the complication rate was 20.8% compared to 13.2% in the endovascular group. Mortality rate was 5.6%. CONCLUSIONS: Our review identified 193 cases of infective native extracranial carotid artery aneurysms. Direct local spread of a staphylococcus infection was the commonest cause. Endovascular management was associated with fewer early complications than open surgical management.

Carotid Artery Stenting for Patients With Carotid Stenosis and Contralateral Carotid Artery Occlusion: A 12-Year Experience.

BACKGROUND: Carotid artery stenting (CAS) has emerged as a potential alternative for treating patients with extracranial cerebrovascular diseases. Contralateral carotid artery occlusion (CCO) occurs in approximately 2.3% to 25% of patients with carotid artery stenosis. However, the association of a CCO with long-term outcomes after CAS remains unclear. Here, we aimed to evaluate the perioperative and long-term recovery and safety of patients with CCO after receiving CAS. METHODS: We retrospectively collected the data of patients with CCO treated with CAS between 2010 and 2021. The primary end point was a nonfatal major stroke. The secondary end points included cerebral hemorrhage, nonfatal myocardial infarction, restenosis, acute renal insufficiency, stent-related complications, and death. Long-term outcomes were analyzed by Kaplan-Meier survival analysis using the following variables: symptomatic carotid stenosis, age, stent type, collateral flow status, and postdilation. RESULTS: Seventy one consecutive patients with CCO who underwent CAS were included in the study. Of these, 61 patients (86%) were followed up for 9-134 months, with an average of 63.3 ± 30.4 months. In the perioperative period, 2 patients (2.8%) experienced stroke and 1 patient (1.4%) died due to cerebral hemorrhage combined with cerebral hernia. During follow-up, 2 patients (3.3%) developed stroke at 4 and 6 months each after CAS and 6 patients (9.8%) died (2 patients died due to myocardial infarction and 4 patients died due to either severe liver failure, car accident, cervical fracture, or unknown cause). Kaplan-Meier survival analysis showed that symptomatic carotid stenosis, age, stent type, and postdilation were not associated with long-term stroke (P＜0.05). The inadequate collateral flow group showed a higher stroke rate than the control group (P = 0.009). CONCLUSIONS: CAS is a safe and effective therapy for patients with CCO. Inadequate collateral flow is associated with a higher long-term rate of stroke. Our findings revealed that symptomatic carotid stenosis, age, stent type, and postdilation had no significant effect on outcome events after CAS.

Does Modified Rankin Score (mRS) Matter? The Impact of Stroke Severity on Carotid Artery Endarterectomy (CEA) Outcomes.

BACKGROUND: Carotid artery endarterectomy (CEA) is recommended to reduce stroke risk in patients following nondisabling ischemic stroke (modified Rankin Score mRS<3). We reviewed CEA outcomes in patients after more devastating strokes (mRS≥3). METHODS: An observational cohort study was performed, and data were collected from 1013 CEA cases over 15 years. Patient demographics, comorbidities and postoperative outcomes were compared between preoperative mRS<3 (Group 1) and mRS≥3 (Group 2). Statistical significance was determined by P < 0.05. RESULTS: Ninety-one (9%) patients were mRS ≥3. There was no significant difference between age, gender, and operated side. Group 2 had significantly higher rates of diabetes and frailty. There was no significant difference in anesthetic type. Group 2 spent longer in High Dependency. Return to theater and postoperative complications were similar. Incidence of perioperative stroke, mortality, and readmission rates were not significant at 30 days postoperation between the 2 groups. CONCLUSIONS: Patients with a higher mRS have more preoperative comorbidities but short-term perioperative complication rate is not significantly different. Patient selection should be undertaken with care.

A Multicenter Analysis of Revision of Aneurysmal Dialysis Access Using Bovine Carotid Artery Conduit.

BACKGROUND: Dialysis access complications and failure requiring revision are common. Understanding which methods of revision yield the optimal patency rates and lowest complications remain in evolution. Revision of native vessels is preferred, with revision using expanded polytetrafluoroethylene (ePTFE) graft as an alternative. Revision with Bovine Carotid Artery Graft (Artegraft) has historically been indicated when other options have been exhausted. While earlier studies demonstrated lower patency and higher infection rates compared to ePTFE, more recent studies have suggested otherwise. We describe our experience with patients who underwent arteriovenous access revision with Artegraft, and present this as a viable alternative. METHODS: A multicenter analysis was conducted over 6 years of 25 patients with arteriovenous access complications requiring revision. Complications included aneurysmal degeneration, bleeding, recurrent thrombosis, and sclerotic outflow. Patients were grouped into 2 groups based on the complication. The first group included aneurysm-only complication and the second group included aneurysm and all other complications. All patients underwent revision of their arteriovenous fistula with excision of diseased segment of the arteriovenous fistula and interposition placement of Artegraft. All patients were followed long term and assessed for postop complications, patency, and any reintervention. RESULTS: Of 25 patients, 13 were male and 12 female. Average age was 57 (range 27-83). Sixteen of the 25 patients had follow-up. Of the 16, 10 patients had primary patency (62.5%), 3 with primary-assisted patency (18.75%), and 3 with failure of grafts (18.75%). Ten of the 16 had at least 1 year or greater follow-up (5 with primary patency, 3 primary-assisted patency, and 2 with failure both of which failed after 1 year). Those that required intervention to maintain patency were from thrombosis requiring declot or anastomotic stenosis requiring angioplasty. None of the followed patients were found to have neither postoperative surgical site nor graft infections. CONCLUSIONS: This case series supports that arteriovenous access revision with Artegraft is a viable option that has acceptable patency rates (81% overall functional patency rate at 1.5 years), with an observed 0% infection rate, and is comparable to ePTFE. With more recent studies suggesting Artegraft may have superior outcomes, further study and consideration should be given to using Artegraft as a conduit for arteriovenous fistula revision.

The effect of bovine serum albumin-glutaraldehyde and polyethylene glycol polymer on local tissue reaction and inflammation in rabbit carotid artery anastomosis.

OBJECTIVES: In addition to the hemostatic properties of hemostatic agents, the investigation of their immunogenic properties, their local effects on application area has been the subject of many experimental studies. There are limited data on the inflammatory effects of Bovine serum albumin-glutaraldehyde and Polyethylene glycol polymer. Therefore, we investigated the effects of these agents on tissue reactions and inflammation in rabbit carotid artery anastomosis in our experimental study. METHODS: Twenty-one New Zealand male rabbits were randomly divided into three groups. The right carotid artery anastomosis was performed on the control group after transection. Hemostatic agents were applied locally to other two groups separately after transection and anastomosis. At the end of 28 days, the type of inflammation, inflammatory cell infiltration, degree of inflammation, and amount of residual adhesives were examined and compared statistically. RESULTS: Cell infiltrations associated with inflammation on the anastomosis site (eosinophils, epithelioid/giant cells, lymphocytes, and plasma cells) and inflammation grade in the groups of hemostatic agents were significantly lower compared to the control group (p < .05). There was no difference between the hemostatic agents. While mild inflammation (61.9%) was dominant in the groups of hemostatic agents, moderate inflammation (85.7%) was more common in the control group. No severe inflammation was observed in any of the three groups. Residual sealant grade between hemostatic agents did not differ significantly. CONCLUSIONS: When inflammation and tissue reactions of the 4th week were evaluated, it was determined that both hemostatic agents did not cause severe inflammation. However, comparative results at multiple time intervals are needed due to the dynamic process of inflammation.

Comparison of Carotid Blood Flow Measured by Ultrasound and Cardiac Output in Patients Undergoing Cardiac Surgery.

BACKGROUND: In general, cerebral blood flow accounts for 10-15% of cardiac output (CO), of which about 75% is delivered through the carotid arteries. Hence, if carotid blood flow (CBF) is constantly proportional to CO with high reproducibility and reliability, it would be of great value to measure CBF as an alternative to CO. The aim of this study was to investigate the direct correlation between CBF and CO. We hypothesized that measurement of CBF could be a good substitute for CO, even under more extreme hemodynamic conditions, for a wider range of critically ill patients. METHODS: Patients aged 65-80 years, undergoing elective cardiac surgery were included in this study. CBF in different cardiac cycles were measured by ultrasound: systolic carotid blood flow (SCF), diastolic carotid blood flow (DCF), and total (systolic and diastolic) carotid blood flow (TCF). CO simultaneously was measured by transesophageal echocardiography. RESULTS: For all patients, the correlation coefficients between SCF and CO, TCF and CO were 0.45 and 0.30, respectively, which were statistically significant, but not between DCF and CO. There was no significant correlation between either SCF, TCF or DCF and CO, when CO was <3.5 L/min. CONCLUSIONS: Systolic carotid blood flow may be used as a better index to replace CO. However, the method of direct measurement of CO is essential when the patient's heart function is poor.