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Objective: The objective of this study was to investigate the flow effects in different degrees of thoracic aortic stent graft protrusion extension by creating bird beak effect simulations using accurate 3D geometry and a realistic, nonlinear, elastic biomechanical model using computer-aided software SolidWorks. Methods: Segmentation in 3D of an aortic arch from a computed tomography (CT) scan of a real-life patient was performed using SolidWorks. A parametric analysis of three models was performed: (A) Aortic arch with no stent, (B) 3 mm bird-beak configuration, and (C) 6.5 mm bird-beak configuration. Flow velocity, pressure, vorticity, wall shear stress (WSS), and time average WSS were assessed. Results: The flow velocity in Model A remained relatively constant and low in the area of the ostium of the brachiocephalic artery and doubled in the left subclavian artery. On the contrary, Models B and C showed a decrease in velocity of 52.3 % in the left subclavian artery. Furthermore, Model B showed a drop in velocity of 82.7% below the bird-beak area, whereas Model C showed a decline of 80.9% in this area. The pressure inside the supra-aortic branches was higher in Model B and C compared with Model A. In Model A, vorticity only appeared at the level of the descending aorta, with low to non-vorticity in the aortic arch. In contrast, Models B and C had an average vorticity of 241.4 Hz within the bird beak area. Regarding WSS, Model A, and Model B shared similar WSS in the peak systolic phase, in the aortic arch, and the bird beak area, whereas Model C had an increased WSS by 5 Pa on average at these zones. Conclusion: In the present simulations' lower velocities, higher pressures, vortices, and WSS were observed around the bird beak zone, the aortic arch, and the supra-aortic vessels. [ABSTRACT FROM AUTHOR]

Data on characteristics and outcomes of coronavirus (COVID)-19 patients complicated with arterial thrombosis (AT) are scarce. Therefore, we carried out a systematic review (PRISMA, PROSPERO statements; PubMed, Scopus, and Web of Science) to identify risk factors, clinical presentation, treatment, and outcomes. We included publications from December 2019 to October 2020. Groups: (a) ischemic stroke, (b) thrombotic storm, (c) peripheral vascular thrombosis, (d) myocardial infarction, and (e) left cardiac thrombus or in-transit thrombus (venous system thrombus floating or attaching to the right heart). We considered 131 studies. The most frequent cardiovascular risk factors were: hypertension, diabetes, and dyslipidemia. A high proportion presented with asymptomatic, mild, or moderate COVID-19 (n = 91, 41.4%). We identified a high percentage of isolated ischemic stroke and thrombotic storm. Groups with higher mortality rate: intracardiac thrombus (1/2, 50.0%), thrombotic storm (18/49, 36.7%), and ischemic stroke (48/131, 36.6%). A small number received thromboprophylaxis. Most patients received antithrombotic treatment. The most frequent bleeding complication was intracranial hemorrhage, primarily with isolated stroke. Overall mortality was 33.6% (74/220). Despite a wide range of COVID-19 severity, a high proportion had AT as a complication of non-severe disease. AT can affect different vascular territories; mortality is associated with stroke, intensive care unit stay, and severe COVID-19. [ABSTRACT FROM AUTHOR]

Background: When treating aortic aneurysm patients with complex anatomical features, preprocedural planning aided by 3D-printed models offers valuable insights for endovascular intervention. This study highlights the use of stereolithographic (SLA) 3D printing to fabricate a phantom of a challenging aortic arch aneurysm with a complex neck anatomy. Clinical Case: A 75-year-old female presented with a 58 mm descending thoracic aortic aneurysm (TAA) extending to the distal arch, involving the left subclavian artery (LSA) and the left common carotid artery (LCCA). The computed tomography (CT) scans underwent scrutiny by radiology and vascular teams. Nevertheless, the precise spatial relationships of the ostial origins proved to be challenging to ascertain. To address this, a patient-specific phantom of the aortic arch was fabricated utilizing an SLA printer and a biomedical resin. The thoracic endovascular aortic repair (TEVAR) procedure was simulated using fluoroscopy on the phantom to enhance procedural preparedness. Subsequently, the patient underwent a right carotid-left carotid bypass and a right carotid-left subclavian bypass. After a 24-hour interval, the patient underwent the TEVAR procedure, during which a 37 mm × 150 mm stent graft (CTAG, WL Gore and Associates, Flagstaff, AZ, USA) and a 40 mm × 200 mm stent graft (CTAG, WL Gore and Associates, Flagstaff, AZ, USA) were deployed, effectively covering the LSA and LCCA. Notably, the aneurysm exhibited complete sealing, with no indications of endoleaks or graft infoldings. At the 12-month follow-up, the patient remains in good health, with no evidence of endoleaks or any other surgery-related complication. Conclusion: This report showcases the successful use of a 3D-printed endovascular phantom in guiding the decision-making process during the preparation for a TEVAR procedure. The simulation played a pivotal role in selecting the appropriate stent graft, ensuring an intervention protocol optimized based on the patient-specific anatomy. [ABSTRACT FROM AUTHOR]

An ideal vascular phantom should be anatomically accurate, have mechanical properties as close as possible to the tissue, and be sufficiently transparent for ease of visualization. However, materials that enable the convergence of these characteristics have remained elusive. The fabrication of patient‐specific vascular phantoms with high anatomical fidelity, optical transparency, and mechanical properties close to those of vascular tissue is reported. These final properties are achieved by 3D printing patient‐specific vascular models with commercial elastomeric acrylic‐based resins before coating them with thiol‐based photopolymerizable resins. Ternary thiol‐ene‐acrylate chemistry is found optimal. A PETMP/allyl glycerol ether (AGE)/polyethylene glycol diacrylate (PEGDA) coating with a 30/70% AGE/PEGDA ratio applied on a flexible resin yielded elastic modulus, UTS, and elongation of 3.41 MPa, 1.76 MPa, and 63.2%, respectively, in range with the human aortic wall. The PETMP/AGE/PEGDA coating doubled the optical transmission from 40% to 80%, approaching 88% of the benchmark silicone‐based elastomer. Higher transparency correlates with a decrease in surface roughness from 2000 to 90 nm after coating. Coated 3D‐printed anatomical replicas are showcased for pre‐procedural planning and medical training with good radio‐opacity and echogenicity. Thiol‐click chemistry coatings, as a surface treatment for elastomeric stereolithographic 3D‐printed objects, address inherent limitations of photopolymer‐based additive manufacturing. [ABSTRACT FROM AUTHOR]

There is no definitive consensus on the impact of preoperative embolization on carotid body tumor (CBT) treatment. The objective of this study was to compare surgical outcomes of patients who underwent preoperative embolization before CBT resection vs patients who underwent resection alone. The CAPACITY registry included 1432 patients with CBT from 11 medical centers in four different countries. The group of patients undergoing CBT resection with preoperative embolization was matched in a 1:6 ratio from a pool of patients from the CAPACITY database, using a generated propensity score with patients who did not underwent preoperative embolization. A total of 553 patients were included for analysis. Mean patient age was 56.23 ± 12.22 years. Patients were mostly female (n = 469; 84.8%). Bilateral CBT was registered in 60 patients (10.8%). Seventy-nine patients (14.3%) underwent preoperative embolization. Embolized patients had larger CBT sizes than non-embolized patients (33.8 mm vs 18.4 mm; P =.0001). Operative blood loss was lower in the embolized group compared with the non-embolized group (200 mL vs 250 mL; P =.031). Hematomas were more frequent in the non-embolized group (0% vs 2.7%; P =.044). Operative time, rates of stroke, cranial nerve injuries, and death were not statistically significant between groups. Embolization before CBT resection was associated with significantly lower blood loss and lower neck hematomas than patients who underwent resection alone. Operative time, stroke, cranial nerve injuries, and death were similar between groups. [ABSTRACT FROM AUTHOR]

Background/Objective: Deep vein thrombosis and pulmonary embolism have been described as complications in previously diagnosed COVID-19 patients, especially in those admitted in critical ill units, but, to our knowledge, there is no report of venous thromboembolism in an otherwise asymptomatic COVID-19 patient. Methods: We report the case of a 22-year-old female, healthy patient with pulmonary embolism (Pulmonary Embolism Severity Index Score 22 points, low risk) and extensive proximal deep vein thrombosis as a unique clinical manifestation of the new coronavirus disease. Results: The patient had no risk factors and no familial history of venous thromboembolism. All thrombophilia markers were negative. The patient was treated as first by an independent vascular team, performing vena cava filter placement and open thrombectomy. Her symptoms worsened, and after 3 weeks, she underwent US-enhanced thrombolysis and mechanical thrombectomy. She was isolated for 10 days and did not develop any other clinical manifestation of COVID-19 disease. During follow-up, she remained asymptomatic and complete patency of the venous system was achieved. Full oral anticoagulation was conducted for 6 months. Conclusion: COVID-19 appears to be a multi-symptomatic disease, and venous thromboembolism without any other previous described COVID-19 symptom could be considered one of its diverse clinical presentations and RT-PCR for SARS-CoV-2 tests emerge to be mandatory in patients with otherwise unexpected venous thrombosis. [ABSTRACT FROM AUTHOR]

Purpose: A systematic review of all patients that have been reported in the literature with abdominal aortic aneurysm (AAA) concomitant with horseshoe kidney (HSK) treated electively by endovascular aneurysm repair (EVAR) is presented. A new grouping system for describing HSK vasculature is implemented.Materials and Methods: We searched for published manuscripts using the Medical Subject Headings terms "abdominal aortic aneurysm," "AAA," "EVAR," "endovascular aneurysm repair," and "horseshoe kidney" in PubMed, Google Scholar, Scopus, and National Center for Biotechnology Information databases. Inclusion criteria include all published material of patients with AAA with HSK treated electively by an endovascular approach. We excluded patients who were treated by a hybrid or open repair or patients with ruptured AAA. Statistical analysis was carried out using SPSS Statistics version 25 (IBM Corp, Armonk, New York) software.Results: A total of 50 patients from 30 studies were included for analysis. Males made up 88% (n=44) of the population. The median age for this cohort was 70 years (range: 47-86 years). Median aneurysmal diameter was 6.0 cm (range: 4.0-10.3 cm). The median operative time for endovascular repair was 84 minutes (range: 40-332 minutes). The most common graft used was Zenith, used in 40% (n=20) of the cases, followed by Endurant in 14% (n=7). The overall complication rate was 14% (n=7). The median follow-up was 19 months (range: 1-108 months). While comorbidities did not appear to impact outcomes significantly, median operative times for smokers were higher than those in nonsmokers, 84 versus 118 minutes, respectively (p=0.048). Univariate linear regression modeling of aneurysmal size with age, operative time, and length of stay revealed a significant coefficient association between aneurysmal size and operative times. After adjusting for comorbidities and aneurysmal size, prior history of chronic kidney disease significantly increased odds for renal infarction.Conclusion: This review presents the most complete data set possible of patients with concomitant HSK and AAA treated by an endovascular approach. Furthermore, the A + B + C classification for grouping the HSK vasculature is implemented. This systematic review suggests EVAR to be an excellent option with low complication rates for the treatment of AAA in patients with HSK. [ABSTRACT FROM AUTHOR]

Objective: Endovascular treatment through either percutaneous transluminal angioplasty (PTA) alone or stenting has been previously used as a treatment for transplant renal artery stenosis (TRAS). This review aimed to investigate the results of endovascular treatment for renal artery stenosis in transplanted kidneys as compared with the outcomes of interventions, medical management, and graft survival in non-TRAS patients. Methods: A systematic review of PubMed, Google Scholar, Cochrane, and Scopus was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in which studies that reported outcomes of the treatment of TRAS via the endoluminal approach were identified, and their results were meta-analyzed. Results: Fifty-four studies with a total of 1522 patients were included. A significant reduction of serum creatinine level was found, favoring the stenting group, with a mean difference of 0.68 mg/dL (95% confidence interval (CI), 0.17–1.19; Z =2.60, p=0.0009). Comparison of pre- and post-intervention values of any intervention revealed a significant decrease in overall serum creatinine level (0.65 mg/dL; 95% CI, 0.40–0.90; Z =5.09, p=0.00001), overall blood pressure, with a mean difference of 11.12 mmHg (95% CI, 7.29–14.95; Z =5.59, p=0.00001), mean difference in the use of medications (0.77; 95% CI, 0.29–1.24; p=0.002), and peak systolic velocity (190.05; 95% CI, 128.41–251.69; p<0.00001). The comparison of serum creatinine level between endovascular interventions and best medical therapy favored endovascular intervention, with a mean difference of 0.23 mg/dL (95% CI, 0.14–0.32; Z =5.07, p<0.00001). Graft survival was similar between the treated patients and those without TRAS (hazard ratio, 0.98; 95% CI, 0.75–1.28; p=0.091). The overall pooled success rate was 89%, and the overall complication rate was 10.4%, with the most prevalent complication being arterial dissection. Conclusion: The endovascular treatment of TRAS improves graft preservation and renal function and hemodynamic parameters. PTA + stenting appears to be a more effective option to PTA alone in the stabilization of renal function, with additional benefits from decreased restenosis rates. Further high-quality studies could expand on these findings. [ABSTRACT FROM AUTHOR]

Background: Academic interaction with mentors has almost become minimal due to the current pandemic of COVID-19. The objective of this study is to introduce how a group of vascular surgery residencies joined forces to improve surgical education in times of COVID-19. Methods: On May 2020, a group of Hispanic American vascular residency programs created webinar sessions of arterial and venous clinical cases among vascular residents across Latin America and Europe. Participants were surveyed via email. Questions were about the perceived quality and utility of the webinars; answers were stratified into negative (disagree), neutral, and positive (agree). Results: There have been 60 sessions and 118 clinical cases presented. The survey was answered by 106 participants, 82 males (78.8%) and 24 women (23.0%). Fifty-four (51.9%) were board-certified vascular surgeons, 49 (47.1%) vascular surgery residents, and 2 (1.9%) general surgery residents. Mean age of the participants was 41.5 years (range: 25–74 years). Mean years of vascular surgery practice or experience were 11.2 years (range: 0–45 years). The residency programs involved in this project were from 13 different countries. Most answers received were positive for both perceived quality and utility of the webinars. Conclusion: Globalization and technology provide an opportunity for international education, with the goal of building well-rounded and academic vascular surgeons. This group is just the beginning of a large collaborative group among Hispanic American countries, hoping that more residency programs will join, with the aim of breaking borders in the education of vascular surgery. [ABSTRACT FROM AUTHOR]