Certification of Basic Skills in Endovascular Aortic Repair Through a Modular Simulation Course With Real Time Performance Assessment.

OBJECTIVE: Endovascular aortic repair (EVAR) is being used increasingly for the treatment of infrarenal abdominal aortic aneurysms. Improvement in educational strategies is required to teach future vascular surgeons EVAR skills, but a comprehensive, pre-defined e-learning and simulation curriculum remains to be developed and tested. EndoVascular Aortic Repair Assessment of Technical Expertise (EVARATE), an assessment tool for simulation based education (SBE) in EVAR, has previously been designed to assess EVAR skills, and a pass limit defining mastery level has been set. However, EVARATE was developed for anonymous video ratings in a research setting, and its feasibility for real time ratings in a standardised SBE programme in EVAR is unproven. This study aimed to test the effect of a newly developed simulation based modular course in EVAR. In addition, the applicability of EVARATE for real time performance assessments was investigated. METHODS: The European Society of Vascular Surgery (ESVS) and Copenhagen Certification Programme in EVAR (ENHANCE-EVAR) was tested in a prospective cohort study. ENHANCE-EVAR is a modular SBE programme in EVAR consisting of e-learning and hands-on SBE. Participants were rated with the EVARATE tool by experienced EVAR surgeons. RESULTS: Twenty-four physicians completed the study. The mean improvement in EVARATE score during the course was +11.8 (95% confidence interval 9.8 - 13.7) points (p < .001). Twenty-two participants (92%) passed with a mean number of 2.8 ± 0.7 test attempts to reach the pass limit. Cronbach's alpha coefficient was 0.91, corresponding to excellent reliability of the EVARATE scale. Differences between instructors' EVARATE ratings were insignificant (p = .16), with a maximum variation between instructors of ± 1.3 points. CONCLUSION: ENHANCE-EVAR, a comprehensive certifying EVAR course, was proven to be effective. EndoVascular Aortic Repair Assessment of Technical Expertise (EVARATE) is a trustworthy tool for assessing performance within an authentic educational setting, enabling real time feedback.

Continuous Glucose Monitoring Reveals Perioperative Hypoglycemia in Most Patients With Diabetes Undergoing Major Surgery: A Prospective Cohort Study.

OBJECTIVE: To investigate the frequency and duration of hypo- and hyperglycemia, assessed by continuous glucose monitoring (CGM) during and after major surgery, in departments with implemented diabetes care protocols. SUMMARY BACKGROUND DATA: Inadequate glycemic control in the perioperative period is associated with serious adverse events, but monitoring currently relies on point blood glucose measurements, which may underreport glucose excursions. METHODS: Adult patients without (A) or with diabetes [non-insulin-treated type 2 (B), insulin-treated type 2 (C) or type 1 (D)] undergoing major surgery were monitored using CGM (Dexcom G6), with an electrochemical sensor in the interstitial fluid, during surgery and for up to 10 days postoperatively. Patients and health care staff were blinded to CGM values, and glucose management adhered to the standard diabetes care protocol. Thirty-day postoperative serious adverse events were recorded. The primary outcome was duration of hypoglycemia (glucose <70 mg/dL). Clinicaltrials.gov: NCT04473001. RESULTS: Seventy patients were included, with a median observation time of 4.0 days. CGM was recorded in median 96% of the observation time. The median daily duration of hypoglycemia was 2.5 minutes without significant difference between the 4 groups (A-D). Hypoglycemic events lasting ≥15 minutes occurred in 43% of all patients and 70% of patients with type 1 diabetes. Patients with type 1 diabetes spent a median of 40% of the monitoring time in the normoglycemic range 70 to 180 mg/dL and 27% in the hyperglycemic range >250 mg/dL. Duration of preceding hypo- and hyperglycemia tended to be longer in patients with serious adverse events, compared with patients without events, but these were exploratory analyses. CONCLUSIONS: Significant duration of both hypo- and hyperglycemia was detected in high proportions of patients, particularly in patients with diabetes, despite protocolized perioperative diabetes management.

Anticoagulants and reduced thrombus load in abdominal aortic aneurysms assessed with three-dimensional contrast-enhanced ultrasound examination.

OBJECTIVE: The relationship between intraluminal thrombus (ILT) and abdominal aortic aneurysm (AAA) growth and rupture risk remains ambiguous. Studies have shown a limited effect of antiplatelet therapy on ILT size, whereas the impact of anticoagulant therapy on ILT is unresolved. This study aims to evaluate an association between antithrombotic therapy and ILT size assessed with three-dimensional contrast-enhanced ultrasound (3D-CEUS) examination in a cohort of patients with AAA. METHODS: In a cross-sectional study, 309 patients with small AAAs were examined with 3D-CEUS. Patients were divided into three groups based on prescribed antithrombotic therapy: anticoagulant (n = 36), antiplatelet (n = 222), and no antithrombotic therapy (n = 51). Patient ILT size was calculated in volume and thickness and compared between the three groups. RESULTS: Patients on anticoagulants had a significantly lower estimated marginal mean ILT volume of 16 mL (standard error [SE], ±3.2) compared with 28 mL (SE, ±2.7) in the no antithrombotic group and 30 mL (SE, ±1.3) in the antiplatelet group when adjusting for AAA volume (P < .001) and comorbidities (P < .001). In addition, patients on anticoagulant therapy had significantly lower estimated marginal mean ILT thickness of 10 mm (SE, ±1.1) compared with 13 mm (SE, ±0.9) in the no antithrombotic group of and 13mm (SE, ±0.4) in the antiplatelet group when adjusting for AAA diameter (P = .03) and comorbidities (P = .035). CONCLUSIONS: A 3D-CEUS examination is applicable for ILT assessment and demonstrates that patients with AAA on anticoagulant therapy have lower ILT thickness and volume than patients with AAA on antiplatelet therapy and those without antithrombotic therapy. Causality between anticoagulants and ILT size, and extrapolation to AAA growth and rupture risk, is unknown and merits further investigations, to further nuance US-based AAA surveillance strategy.

Hyperoxia and Antioxidants for Myocardial Injury in Noncardiac Surgery: A 2 × 2 Factorial, Blinded, Randomized Clinical Trial.

BACKGROUND: Hyperoxia and oxidative stress may be associated with increased risk of myocardial injury. The authors hypothesized that a perioperative inspiratory oxygen fraction of 0.80 versus 0.30 would increase the degree of myocardial injury within the first 3 days of surgery, and that an antioxidant intervention would reduce degree of myocardial injury versus placebo. METHODS: A 2 × 2 factorial, randomized, blinded, multicenter trial enrolled patients older than 45 yr who had cardiovascular risk factors undergoing major noncardiac surgery. Factorial randomization allocated patients to one of two oxygen interventions from intubation and at 2 h after surgery, as well as antioxidant intervention or matching placebo. Antioxidants were 3 g IV vitamin C and 100 mg/kg N-acetylcysteine. The primary outcome was the degree of myocardial injury assessed by the area under the curve for high-sensitive troponin within the first 3 postoperative days. RESULTS: The authors randomized 600 participants from April 2018 to January 2020 and analyzed 576 patients for the primary outcome. Baseline and intraoperative characteristics did not differ between groups. The primary outcome was 35 ng · day/l (19 to 58) in the 80% oxygen group; 35 ng · day/l (17 to 56) in the 30% oxygen group; 35 ng · day/l (19 to 54) in the antioxidants group; and 33 ng · day/l (18 to 57) in the placebo group. The median difference between oxygen groups was 1.5 ng · day/l (95% CI, -2.5 to 5.3; P = 0.202) and -0.5 ng · day/l (95% CI, -4.5 to 3.0; P = 0.228) between antioxidant groups. Mortality at 30 days occurred in 9 of 576 patients (1.6%; odds ratio, 2.01 [95% CI, 0.50 to 8.1]; P = 0.329 for the 80% vs. 30% oxygen groups; and odds ratio, 0.79 [95% CI, 0.214 to 2.99]; P = 0.732 for the antioxidants vs. placebo groups). CONCLUSIONS: Perioperative interventions with high inspiratory oxygen fraction and antioxidants did not change the degree of myocardial injury within the first 3 days of surgery. This implies safety with 80% oxygen and no cardiovascular benefits of vitamin C and N-acetylcysteine in major noncardiac surgery.

Simulation Based Training and Assessment in Open Vascular Surgery: A Systematic Review.

OBJECTIVE: The aim of this study was to systematically review the literature and give evidence based recommendations for future initiatives for simulation based training (SBT) and assessment in open vascular surgery. DATA SOURCES: PubMed, Embase, and the Cochrane Library. REVIEW METHODS: A systematic review of PubMed, Embase, and the Cochrane Library was performed, with the last search on 31 March 2020, to identify studies describing SBT and assessment in open vascular surgery. Kirkpatrick's levels for efficacy of training were evaluated. Validity evidence for assessment tools was evaluated according to the recommended contemporary framework by Messick. RESULTS: Of 2 844 studies, 51 were included for data extraction. A high degree of heterogeneity in reporting standards and varying types of simulation was found. Vascular anastomosis was the most frequently simulated technical skill (43%). Assessment was mostly carried out using the Objective Structured Assessment of Technical Skills (55%). Validity evidence for assessment tools was found using outdated frameworks, and only one study used Messick's framework. Self directed training is valuable, the low trainer to trainee ratio is important to maximise efficiency, and experienced vascular surgeons are the most effective trainers. CONCLUSION: Carefully designed and structured SBT is effective and can improve technical skills, especially in less experienced trainees. However, the supporting evidence lacks homogeneity in the reporting standards and types of simulations. Pass/fail standards that support proficiency based learning and studies investigating skills transfer should be the focus in future studies. Validity evidence of assessment tools needs to be addressed using contemporary frameworks.

Three- and Two-Dimensional Ultrasound is as Accurate as Computed Tomography in Aortic Sac Assessment after Endovascular Aortic Repair.

BACKGROUND: To compare aortic sac changes after endovascular aneurysm repair (EVAR) assessed by three-dimensional ultrasound (3D-US), two-dimensional ultrasound (2D-US), and traditional computed tomographic angiography (CTA). METHODS: Using volume assessment with three-dimensional CTA (3D-CTA-volume) as the gold standard, this study investigated aortic sac changes at three and 12 months after EVAR with three different ultrasound methods (2D-US anterior-posterior (AP) diameter, 3D-US AP centerline diameter, and 3D-US partial volume), and traditional CT multiplanar outer-to-outer diameter (CT-MPR OTO diameter). From august 1st, 2011 to January 2014, consecutive EVAR patients (n = 113) were available for analysis in two time intervals; 1) between preoperative and three-month follow-up and 2) between three and 12 month follow-up. RESULTS: The risk of missing true aortic sac growth (false negative finding) at three-month postoperative visit using 3D-US partial volume, 3D-US AP centerline diameter, 2D-US AP diameter, and CT-MPR OTO diameter was 19%, 21%, 22%, and 18%, respectively. Corresponding low sensitivities (0% to 21%) and kappa-values (<0.50) in detecting aortic sac changes were found. The risk of missing true growth between three and 12 months were lower (6%, 5%, 6%, and 6%, respectively), and matching sensitivities 33%, 33%, 17%, and 17%, respectively. CONCLUSIONS: All tested methods for aortic sac changes were as good as traditional CT-MPR OTO diameter and corresponded poorly with 3D-CTA-volume at three months postoperative visit but substantially better after 12 months where the residual sac change was more profound.

The Short-term Predictive Value of Vessel Wall Stiffness on Abdominal Aortic Aneurysm Growth.

BACKGROUND: Abdominal aortic aneurysm (AAA) surveillance programs are currently based solely on AAA diameter. The diameter criterion alone, however, seems inadequate as small AAAs comprise 5-10 % of ruptured AAAs as well as some large AAAs never rupture. Aneurysm wall stiffness has been suggested to predict rupture and growth; this study aimed to investigate the prognostic value of AAA vessel wall stiffness for growth on prospectively collected data. METHODS: Analysis was based on data from a randomised, placebo-controlled, multicentre trial investigating mast-cell-inhibitors to halt aneurysm growth (the AORTA trial). Systolic and diastolic AAA diameter was determined in 326 patients using electrocardiogram-gated ultrasound (US). Stiffness was calculated at baseline and after 1 year. RESULTS: Maximum AAA diameter increased from 44.1 mm to 46.5 mm during the study period. Aneurysm growth after 1 year was not predicted by baseline stiffness (-0.003 mm/U; 95 % CI: -0.007 to 0.001 mm/U; P = 0.15). Throughout the study period, stiffness remained unchanged (8.3 U; 95 % CI: -2.5 to 19.1 U; P = 0.13) and without significant correlation to aneurysm growth (R: 0.053; P = 0.38). CONCLUSIONS: Following a rigorous US protocol, this study could not confirm AAA vessel wall stiffness as a predictor of aneurysm growth in a 1-year follow-up design. The need for new and subtle methods to complement diameter for improved AAA risk assessment is warranted.

Laser speckle contrast imaging of forehead cutaneous blood flow during carotid endarterectomy as a potential non-invasive method for surrogate monitoring of cerebral perfusion.

Monitoring cerebral perfusion is important for goal-directed anesthesia. Taking advantage of the supply of the supraorbital region and Glabella from the internal carotid artery (ICA), we evaluated changes in cutaneous blood flow using laser speckle contrast imagining (LSCI) as a potential method for indirect real-time monitoring of cerebral perfusion. Nine patients (8 men, mean age 70 years) underwent eversion carotid endarterectomy under local anesthesia. Cutaneous blood flow of the forehead was monitored using LSCI. During clamping of the common carotid artery (CCA), ipsilateral supraorbital region and Glabellas cutaneous blood flow dropped from 334 ± 135 to 221 ± 109 AU (p = 0.023) (AU: arbitrary flux units) and from 384 ± 151 to 276 ± 107 AU (p = 0.023), respectively, whilst the contralateral supraorbital region cutaneous blood flow remained unchanged. The supraorbital cutaneous blood flow did not change significantly following reperfusion of the external carotid artery (ECA) (221 ± 109 to 281 ± 154 AU; p = 0.175) and ICA (281 ± 154 to 310 ± 184 AU; p = 01). A comparable trend for Glabella followed ECA (276 ± 107 to 342 ± 170 AU; p = 0.404) and ICA (342 ± 170 to 352 ± 191 AU; p = 01) reperfusion. In patients undergoing carotid endarterectomy under local anesthesia, LSCI of the supraorbital and Glabella regions reflected clamping of the CCA but did not distinguish reperfusion of the ICA from that of the ECA.

Achieving Consensus to Define Curricular Content for Simulation Based Education in Vascular Surgery: A Europe Wide Needs Assessment Initiative.

OBJECTIVE: To gather consensus among European educators about technical procedures that should be included in a future simulation based curriculum in vascular surgery. METHODS: A three round modified Delphi survey was initiated among 189 key opinion leaders (KOL) from 34 countries across Europe who were identified according to their positions in the European Society for Vascular Surgery, the European Journal of Vascular and Endovascular Surgery, and Union Européenne des Médecins Spécialistes Section and Board of Vascular Surgery. The first round was a brainstorming phase to identify technical procedures that a newly qualified vascular surgeon should be able to perform. The answers were analysed qualitatively. The second round investigated how often the identified procedures are performed, the number of vascular surgeons that should be able to perform these procedures, whether the procedures pose a risk to the patients, and whether simulation based education (SBE) is feasible. In the third round, elimination and re-ranking of procedures were performed. Only procedures that gained more than 70% support were included. An international steering group consisting of open and endovascular surgeons and medical educators governed the process. RESULTS: Response rates in the three rounds were 75% (142/189), 89% (126/142), and 85% (107/126), respectively. In the final prioritised list of 30 technical procedures for SBE, the top five procedures focus on basic open vascular skills, basic endovascular skills, vascular imaging interpretation, femoral endarterectomy, and open peripheral bypass. Twenty-six procedures were eliminated, including peripheral pressure measurement, wound management, open management of complications, major amputations, and highly advanced endovascular skills. CONCLUSION: The prioritised list of technical procedures from this ESVS supported project could be used to guide planning and development of future SBE programs to meet the needs of vascular surgeons across Europe.

Cutdown Technique is Superior to Fascial Closure for Femoral Artery Access after Elective Endovascular Aortic Repair.

OBJECTIVES: Arterial access closure after endovascular aneurysm repair (EVAR) can be achieved using three different approaches: percutaneous closure devices, surgical exposure and direct suture ("cutdown"), and the less invasive fascial closure technique. The aim of this study was to report on the intra-operative, in hospital, and three month outcome of fascial closure and cutdown, and to determine risk factors for failure. METHODS: The primary outcome was assessed in 439 groins in 225 elective EVAR patients recruited consecutively and prospectively from February 1, 2011 to August 31, 2014. During the study period, fascial closure and cutdown were first and second line closing techniques. Compared with fascial closure, procedures completed with cutdown had lower BMI, thinner subcutaneous tissue of the groin and more complex femoral anatomy. Computed tomographic angiography (CTA) and duplex ultrasound (DUS) of the groin were performed pre-operatively and three months after EVAR. Retrospective review of medical records and CTA were used to determine intra-operative and in hospital outcome, and risk factors for failure. RESULTS: In total, 64%, 33%, and 3% were completed with fascial closure, cutdown, and closure device, respectively. Intra-operative, in hospital, and three month technical success rates of fascial closure vs. cutdown were 91% (283/310 groins) vs. 99% (114/115 groins), 89% (277/310 groins) vs. 99% (114/115 groins), and 89% (275/310 groins) vs. 99% (114/115 groins) (p < .001). Wound complications within three months were infrequent for both methods. No risk factor was significantly associated with failure after fascial closure. CONCLUSION: This study shows that cutdown is superior to fascial closure for femoral artery access after elective EVAR. In acute EVAR, however, fascial closure is still considered to be a good and fast method, and it has been kept in the present authors' armamentarium for this indication.

Contrast Enhanced Three Dimensional Ultrasound for Intraluminal Thrombus Assessment in Abdominal Aortic Aneurysms.

OBJECTIVES: The impact of intraluminal thrombus (ILT) on abdominal aortic aneurysm (AAA) progression can be investigated non-invasively by three dimensional contrast enhanced ultrasound (3D-CEUS). The aim was to validate 3D-CEUS ILT volume and thickness measurements against computed tomography angiography (CTA), and to determine inter- and intra-operator reproducibility. METHODS: The design was for a planned comparison of 3D-CEUS and CTA and of repeated 3D-CEUS measurements in a blinded set up. Consecutive patients with asymptomatic AAA (n = 137, maximum diameter 30-55 mm) from a single centre were consecutively assessed by CTA and 3D-CEUS in a blinded setup. After exclusion of failed CTA (n = 2) and inconclusive 3D-CEUS (n = 8), 127 3D-CEUS/CTA pairs were analysed by Bland-Altman plots. 3D-CEUS inter- and intra-operator reproducibility were determined in a subgroup (n = 30) measured twice by two blinded investigators. RESULTS: In 24 of 127 (19%) patients, no ILT was found on 3D-CEUS. Intraluminal thrombus absence was confirmed by 3D-CTA analysis in all but two cases. Mean ILT volume difference between 3D-CEUS and CTA was 2.2 mL (5% of mean volume) and range of variability (ROV) amounted to ± 10.2 mL. Mean ILT thickness difference was 0.6 mm with a ROV of ± 4.6 mm 3D-CEUS inter-operator variations of ILT volume and thickness measurements were low (ROV ± 8.8 mL and ±2.9 mm, respectively). The corresponding intra-operator ROVs were ±7.5 mL and ±3.3 mm, respectively. CONCLUSIONS: 3D-CEUS demonstrated good reproducibility and a good agreement with CTA when estimating ILT volume and maximum thickness in AAA patients. It is a promising research tool to investigate potential interactions between ILT, AAA growth, and rupture.

Mortality and complications after aortic bifurcated bypass procedures for chronic aortoiliac occlusive disease.

OBJECTIVE: Open surgery has given way to endovascular grafting in patients with aortoiliac occlusive disease. The growing use of endovascular grafts means that fewer patients with aortoiliac occlusive disease have open surgery. The declining open surgery caseload challenges the surgeon's operative skills, particularly because open surgery is increasingly used in those patients who are unsuitable for endovascular repair and hence technically more demanding. We assessed the early outcome after aortic bifurcated bypass procedures during two decades of growing endovascular activity and identified preoperative risk factors. METHODS: Data on patients with chronic limb ischemia were prospectively collected during a 20-year period (1993 to 2012). The data were obtained from the Danish Vascular Registry, assessed, and merged with data from The Danish Civil Registration System. RESULTS: We identified 3623 aortobifemoral and 144 aortobiiliac bypass procedures. The annual caseload fell from 323 to 106 during the study period, but the 30-day mortality at 3.6% (95% confidence interval [CI], 3.0-4.1) and the 30-day major complication rate remained constant at 20% (95% CI, 18-21). Gangrene (odds ratio [OR], 3.3; 95% CI, 1.7-6.5; P = .005) was the most significant risk factor for 30-day mortality, followed by renal insufficiency (OR, 2.5; 95% CI, 1.1-5.8; P = .035) and cardiac disease (OR, 2.1; 95% CI, 1.4-3.1; P < .001). Multiorgan failure, mesenteric ischemia, need for dialysis, and cardiac complications were the most lethal complications, with mortality rates of 94%, 44%, 38%, and 34%, respectively. CONCLUSIONS: Aortic bifurcated bypass is a high-risk procedure. Although open surgery has increasingly given way to endovascular repair, 30-day outcomes have remained stable during the past decade. Thus, it is still acceptable to consider an aortic bifurcated bypass whenever endovascular management is not feasible.

Relationship Between Intraluminal Thrombus Volume and Circulating ADAMTS-13 Activity in Abdominal Aortic Aneurysms.

Introduction: Abdominal aortic aneurysms (AAAs) with intraluminal thrombus (ILT) are suggested to be more prone to rupture than AAAs without. Prior studies indicate that the von Willebrand factor (vWf) plays a role in the formation of ILT since a positive correlation between ILT volume and vWf has been shown. vWf mediates the tethering of platelets at sites of endothelial injury, and the protease ADAMTS-13 cleaves larger forms of vWf, thus counteracting the thrombosis cascade and maintaining haemostatic balance. When investigating the largest quantifiable thrombus in the human body, it was hypothesised that circulating ADAMTS-13 activity may be associated with ILT size in patients with AAA and the aim was to explore this potential relationship using 3D contrast enhanced ultrasound (3D-CEUS) for ILT volume determination. Report: In this retrospective, exploratory study, 60 patients with AAA were evaluated, and the association between ILT volume and thickness and ADAMTS-13 was estimated using 3D-CEUS. ADAMTS-13 activity was measured in plasma samples obtained the same day. No association between ILT volume (r = -0.03, p = 0.84) or ILT thickness (r = 0.02, p = 0.87) and ADAMTS-13 activity was found. Likewise, when subdividing the group into lowest and highest 50% of ADAMTS-13 activity, the half with the lowest ADAMTS-13 activity (mean ILT volume ±standard deviation [SD]: 32 ± 34 mL) did not differ from the half with the highest ADAMTS-13 activity (43 ± 24 mL) when comparing ILT volume (p = 0.172, F = 2.95) and thickness (p = 0.070). Discussion: After evaluating the largest quantifiable intraluminal thrombus in the vasculature, it was concluded that, surprisingly, circulating ADAMTS-13 activity seems unrelated to ILT formation in AAA.

Copenhagen Mesenteric stent study (COMESS)-a randomized trial of stent versus covered stent treatment for chronic mesenteric ischemia.

BACKGROUND: Current management of mesenteric ischemia is primarily endovascular stent treatment. Typical CMI symptoms are postprandial abdominal pain, food fear, weight loss, and diarrhea. Revascularization is often necessary, as mesenteric ischemia may progress to bowel necrosis and death if left untreated. This study aims to compare the outcome using bare metal stent (BMS) or covered stent (CS) in the endovascular treatment of chronic and acute on chronic mesenteric ischemia. METHODS: This is an investigator-driven, prospective, randomized, single-blinded, and single-center, national cohort study at the Copenhagen University Hospital, Denmark. A total of 98 patients with chronic mesenteric ischemia (CMI) and acute-on-chronic mesenteric ischemia (AoCMI) will be randomized to treatment with either BeSmooth BMS (Bentley Innomed GmbH) or BeGraft CS (Bentley Innomed GmbH). Randomization occurs intraoperatively after lesion crossing. DISCUSSION: There is currently no published data from prospective controlled trials regarding the preferred type of stent used for the treatment of chronic and acute-on-chronic mesenteric ischemia. This trial will evaluate the short- and long-term outcome of BMS versus CS when treating CMI and AoCMI, as well as the benefit of a more intense postoperative surveillance program. TRIAL REGISTRATION: ClinicalTrials.gov NCT05244629. Registered on February 8, 2022.

Proteomic analysis of the extracellular matrix of human atherosclerotic plaques shows marked changes between plaque types.

Cardiovascular disease is the leading cause of death, with atherosclerosis the major underlying cause. While often asymptomatic for decades, atherosclerotic plaque destabilization and rupture can arise suddenly and cause acute arterial occlusion or peripheral embolization resulting in myocardial infarction, stroke and lower limb ischaemia. As extracellular matrix (ECM) remodelling is associated with plaque instability, we hypothesized that the ECM composition would differ between plaques. We analyzed atherosclerotic plaques obtained from 21 patients who underwent carotid surgery following recent symptomatic carotid artery stenosis. Plaques were solubilized using a new efficient, single-step approach. Solubilized proteins were digested to peptides, and analyzed by liquid chromatography-mass spectrometry using data-independent acquisition. Identification and quantification of 4498 plaque proteins was achieved, including 354 ECM proteins, with unprecedented coverage and high reproducibility. Multidimensional scaling analysis and hierarchical clustering indicate two distinct clusters, which correlate with macroscopic plaque morphology (soft/unstable versus hard/stable), ultrasound classification (echolucent versus echogenic) and the presence of hemorrhage/ulceration. We identified 714 proteins with differential abundances between these groups. Soft/unstable plaques were enriched in proteins involved in inflammation, ECM remodelling, and protein degradation (e.g. matrix metalloproteinases, cathepsins). In contrast, hard/stable plaques contained higher levels of ECM structural proteins (e.g. collagens, versican, nidogens, biglycan, lumican, proteoglycan 4, mineralization proteins). These data indicate that a single-step proteomics method can provide unique mechanistic insights into ECM remodelling and inflammatory mechanisms within plaques that correlate with clinical parameters, and help rationalize plaque destabilization. These data also provide an approach towards identifying biomarkers for individualized risk profiling of atherosclerosis.

Automated 3D ultrasound bridges the gap between novices and experts in diameter assessment of abdominal aortic aneurysms.

BACKGROUND: The current management of abdominal aortic aneurysm (AAA) hinges upon assessing diameter using ultrasound (US). Diameter reproducibility with conventional two-dimensional ultrasound (2D-US) is challenging and requires experienced operators. A novel automatic three-dimensional ultrasound (3D-US) system enables on-cart software-assisted diameter estimation (3D-SAUS), potentially facilitating more precise diameter measurements than 2D-US. This study aimed to assess the variance of AAA diameter measurements among US novices and experts by comparing 2D-US with 3D-SAUS in a clinical setting. METHODS: A total of 580 US scans were scheduled by 29 US operators (13 experts and 16 novices) on 10 patients with AAAs. Experts and novices measured all patients' AAA anterior-posterior (AP) diameters with 2D-US and 3D-SAUS. Outcomes were limits of agreement (LoA) using a mixed-effects model. RESULTS: In total, 564 of 580 planned US scans were performed. 500 US scans were automatically analyzed by the software and included. When using 3D-SAUS instead of 2D-US, novices reduced their LoA from ±16.5% to ±10.2% (P<0.001), reaching the experts' LoA of ±10.5% (P=0.782 for difference). The experts' LoA was ±10.5% for 2D-US and ±9.7% for 3D-SAUS, with no statistically significant difference between the two modalities (P=0.423). CONCLUSIONS: Clinical implementation of the 3D-SAUS demonstrates a substantial reduction in variance in AAA diameter measurements among novice sonographers, surpassing the performance of conventional 2D-US techniques. Additionally, using the 3D-SAUS tool enables novice sonographers to achieve proficiency levels comparable to those of experts employing conventional 2D-US.

Strain Patterns With Ultrasound for Assessment of Abdominal Aortic Aneurysm Vessel Wall Biomechanics.

BACKGROUND: Abdominal aortic aneurysms (AAAs) are an important cause of death. Small AAAs are surveyed with ultrasound (US) until a defined diameter threshold, often triggering a computer tomography scan and surgical repair. Nevertheless, 5%-10% of AAA ruptures are below threshold, and some large AAAs never rupture. AAA wall biomechanics may reveal vessel wall degradation with potential for patient-centred risk assessment. This clinical study investigated AAA vessel wall biomechanics and deformation patterns, including reproducibility. METHODS: In 50 patients with AAA, 183 video clips were recorded by two sonographers. Prototype software extracted AAA vessel wall principal strain characteristics and patterns. Functional principal component analysis (FPCA) derived strain pattern statistics. RESULTS: Strain patterns demonstrated reduced AAA wall strains close to the spine. The strain pattern "topography" (i.e., curve phases or "peaks" and "valleys") had a 3.9 times lower variance than simple numeric assessment of strain amplitudes, which allowed for clustering in two groups with FPCA. A high mean reproducibility of these clusters of 87.6% was found. Median pulse pressure-normalised mean principal strain (PPPS) was 0.038%/mm Hg (interquartile range: 0.029-0.051%/mm Hg) with no correlation to AAA size (Spearman's ρ = 0.02, false discovery rate-p = 0.15). Inter-operator reproducibility of PPPS was poor (limits of agreement: ±0.031%/mm Hg). DISCUSSION: Strain patterns challenge previous numeric stiffness measures based on anterior-posterior-diameter and are reproducible for clustering. This study's PPPS aligned with prior findings, although clinical reproducibility was poor. In contrast, US-based strain patterns hold promising potential to enhance AAA risk assessment beyond traditional diameter-based metrics.