Perspectives on Surgical Leadership: A Panel Discussion at the Society for Clinical Vascular Surgery.

Leadership is a skill that all surgeons are confronted with in some capacity. Surprisingly in the US most training programs do not offer a structured program in leadership and there certainly are no metrics used to assess leadership competency. As a response to this, at The Society for Clinical Vascular Surgery (SCVS) a panel of leaders in vascular surgery both national and international, along with leadership experts discussed some of the salient issues in this space. This document is the result of this discussion and serves as a good framework for understanding needs and current shortcomings of leadership training.

Fundamental Technical Skills of Endovascular Surgery: A Preliminary Study on Its Impact on Skills and Stress during Procedures.

BACKGROUND: Our objective is twofold: determining if simulation allows residents to reach proficient surgeons' performance concerning fundamental technical skills of endovascular surgery (FEVS) while investigating effects of the program on surgeons' stress. METHODS: Using a FEVS training simulator, 8 endovascular FEVS were performed by vascular surgery residents (simulator-naive or simulator-experienced residents [SER]) and seniors. Total time needed to complete the 8 tasks, called total completion time (TCT), was the main evaluation criterion. Analgesia Nociception Index (ANI) was monitored during simulation. Likert scale questionnaire was filled out after each simulation. RESULTS: For each task, TCT was significantly lower for SER and seniors than simulator-naive residents (P = 0.0163). After only 5 simulations, SER were able to reach and even exceed the seniors' level in terms of TCT, with a median time of 10.8 min for SER and 11.9 min for seniors, and wire's movements with a median distance during cannulation of 4.44 m for SER and 4.17 m for seniors. Seniors remained better than SER in terms of precise wire manipulation (wire movement after cannulation), 4.17 m against 4.44 m (3.72-5.96), respectively. Based on the Likert scale stress analysis, seniors felt less stressed than both residents' groups (P = 0.0618). Seniors' initial ANI and mean ANI over the session were significantly lower than those of the residents, P = 0.0358 and P = 0.0250, respectively. CONCLUSIONS: We showed that 5 simulation sessions allowed residents to reach experienced surgeons' capacities on FEVS concerning TCT. Subjectively, seniors felt less stressed than residents, contrary to the results of our objective measures of stress.

Experimental multiparametric magnetic resonance imaging characterization of iliocaval venous thrombosis pathological changes.

OBJECTIVE: Iliocaval thrombotic obstruction is a challenging condition, especially because thrombus age and corresponding pathological remodeling at presentation are unknown, which directly impacts management. Our aim was to assess the ability of magnetic resonance imaging (MRI) in determining age thresholds of experimentally created inferior vena cava (IVC) thrombosis in pigs. METHODS: We used a previously described swine model of IVC thrombosis. The animals underwent MRI at baseline, immediately after thrombosis creation, and after a follow-up period extending from 2 to 28 days. Thirteen pigs were divided into three groups according to disease chronicity: acute group (AG; n = 5), subacute group (SAG; n = 4), and chronic group (CG; n = 4), with a mean thrombosis age of 6.4 ± 2.5 days, 15.7 ± 2.8 days, and 28 ± 5.7 days, respectively. A T1-weighted volumetric interpolated breath-hold examination sequence was used to anatomically delineate IVC thrombus as a region of interest. Three other MRI sequences were used to assess the thrombus signal. RESULTS: The Kruskal-Wallis test showed a statistically significant difference in T1 relaxation times after contrast injection (P = .026) between the three groups of chronicity. The AG (360.2 ± 102.5 ms) was significantly different from the CG (336.7 ± 55.2 ms; P = .003), and the SAG (354.1 ± 89.7 ms) was significantly different from the AG (P = .027). There was a statistically significant difference in native T2 relaxation times (P = .038) between the three groups. The AG (160 ± 86.7 ms) was significantly different from the SAG (142.3 ± 55.4 ms; P = .027), and the SAG was significantly different from the CG (178.4 ± 11.7 ms; P = .004). CONCLUSIONS: This study highlighted MRI characteristics in a swine model that might have the potential to significantly differentiate subacute and chronic stages from an acute stage of deep vein thrombosis in humans. Further clinical studies in humans are warranted. CLINICAL RELEVANCE: In addition to providing a better understanding of venous thrombosis remodeling over time, magnetic resonance imaging has the potential to be a tool that could allow us to characterize the composition of venous thrombus over an interval, allowing for a refined analysis of the local evolution of venous thrombosis. We propose a noninvasive and innovative method to characterize different thresholds of chronicity with magnetic resonance imaging features of central deep vein thrombosis of the inferior vena cava experimentally obtained using a totally endovascular in vivo swine model, mimicking human pathophysiology. Being able to determine these features noninvasively is critical for vascular specialists when it comes to choosing between fibrinolytic therapy, percutaneous thrombectomy, or surgical management.

Sex-Specific Morphometric Analysis of Ascending Aorta and Aortic Arch for Planning Thoracic Endovascular Aortic Repair: A Retrospective Cohort Study.

OBJECTIVE: In many studies on aortic disease, women are underrepresented. The present study aims to assess sex-specific morphometric differences and gain more insight into endovascular treatment of the ascending aorta (AA) and arch. METHODS: Electrocardiogram-gated cardiac computed tomography scans of 116 consecutive patients who were evaluated for transcatheter aortic valve replacement were retrospectively reviewed. Measurements of the AA and aortic arch were made in multiplanar views, perpendicular to the semi-automatic centerline. Multiple linear regression analysis was performed to identify predictors affecting AA and aortic arch diameter in men and women. Propensity score matching was used to investigate whether sex influences aortic morphology. RESULTS: In both sexes, body surface area (BSA) was identified as a positive predictor and diabetes as a negative predictor for aortic diameters. In men, age was identified as a positive predictor and smoking as a negative predictor for aortic diameters. Propensity score matching identified 40 pairs. Systolic and diastolic mean diameters and AA length were significantly wider in men. On average, male aortas were 7.4% wider than female aortas, both in systole and diastole. CONCLUSIONS: The present analysis demonstrates that, in women, increased BSA is associated with increased aortic arch diameters, while diabetes is associated with decreased AA and arch diameters. In men, increased BSA and age are associated with increased AA and arch diameters, while smoking and diabetes are associated with decreased AA and arch diameters. Men were confirmed to have 7.4% greater AA and arch diameters than women. CLINICAL IMPACT: Men had 7.4% greater ascending aorta and arch diameters than women in a retrospective cohort, gated computed tomography-based study of 116 patients. Sex-specific differences in ascending aortic and arch size should be considered by aortic endovascular device manufacturers and physicians when developing ascending and arch endografts and planning aortic interventions.

Editor's Choice - Trends in Management and Outcomes of Type B Aortic Dissection: A Report From the International Registry of Aortic Dissection.

OBJECTIVE: To describe the trends in management and outcomes of patients with acute type B aortic dissection in the International Registry of Acute Aortic Dissection. METHODS: From 1996 - 2022, 3 908 patients were divided into similar sized quartiles (T1, T2, T3, and T4). In hospital outcomes were analysed for each quartile. Survival rates following admission were compared using Kaplan-Meier analyses with Mantel-Cox Log rank tests. RESULTS: Endovascular treatment increased from 19.1% in T1 to 37.2% in T4 (ptrend < .001). Correspondingly, medical therapy decreased from 65.7% in T1 to 54.0% in T4 (ptrend < .001), and open surgery from 14.8% in T1 to 7.0% in T4 (ptrend < .001). In hospital mortality decreased in the overall cohort from 10.7% in T1 to 6.1% in T4 (ptrend < .001), as well as in medically, endovascularly and surgically treated patients (ptrend = .017, .033, and .011, respectively). Overall post-admission survival at three years increased (T1: 74.8% vs. T4: 77.3%; p = .006). CONCLUSION: Considerable changes in the management of acute type B aortic dissection were observed over time, with a significant increase in the use of endovascular treatment and a corresponding reduction in open surgery and medical management. These changes were associated with a decreased overall in hospital and three year post-admission mortality rate among quartiles.

Experimental Analysis of Radiation Protection Offered by a Novel Exoskeleton-Based Radiation Protection System versus Conventional Lead Aprons.

PURPOSE: To evaluate the radiation protection offered by an exoskeleton-based radiation protection system (Stemrad MD) and to compare it with that offered by conventional lead aprons. METHODS: The experimental setup involved 2 anthropomorphic phantoms, an operator, a patient, and a C-arm as the x-ray radiation source. Thermoluminescent detectors were used to measure radiation doses to different radiosensitive body parts on the operator phantom both with the exoskeleton and a conventional lead apron at the left radial and right femoral positions. Detected radiation doses for the exoskeleton and lead apron for different body parts and positions were compared. RESULTS: At the left radial position, the mean radiation dose (mGy) reduction by the exoskeleton compared with that by the lead apron was >90% for the left eye lens (0.22 ± 0.13 vs 5.18 ± 0.08; P < .0001), right eye lens (0.23 ± 0.13 vs 4.98 ± 0.10; P < .0001), left head (0.11 ± 0.16 vs 3.53 ± 0.07; P < .0001), right head (0.27 ± 0.09 vs 3.12 ± 0.10; P < .0001), and left brain (0.04 ± 0.08 vs 0.46 ± 0.07; P < .0001). At the right femoral position, radiation reduction was >90% for the left eye lens (0.14 ± 0.10 vs 4.16 ± 0.09; P < .0001), right eye lens (0.06 ± 0.08 vs 1.90 ± 0.11; P < .0001), left head (0.10 ± 0.08 vs 4.39 ± 0.08; P < .0001), left brain (0.03 ± 0.07 vs 1.44 ± 0.08; P < .0001), right brain (0.00 ± 0.14 vs 0.11 ± 0.13; P = .06), and thyroid (0.04 ± 0.07 vs 0.27 ± 0.09; P < .0001). Protection of the torso was equivalent to that offered by conventional lead aprons. CONCLUSIONS: The exoskeleton-based system provided superior radiation protection to the physician compared with that provided by conventional lead aprons. The effects are particularly impactful for the brain, eye lens, and head areas.

StemRad MD, An Exoskeleton-Based Radiation Protection System, Reduces Ergonomic Posture Risk Based on a Prospective Observational Study.

OBJECTIVE: Poor ergonomic posture during interventional procedures might lead to increased physical discomfort and work-related musculoskeletal disorders. Adjunctive equipment such as lead aprons (LAs) has been shown to increase ergonomic posture risk (EPR). The objective of this study was to evaluate the effectiveness of StemRad MD (StemRad Ltd., Tel Aviv, Israel), a weightless exoskeleton-based radiation protective ensemble, in reducing EPR on the operator using wearable inertial measurement unit (IMU) sensors. METHODS: A prospective, observational study was conducted at an academic hospital. Inertial measurement unit sensors were affixed to the upper back of 9 interventionalists to assess ergonomic risk posture during endovascular procedures while wearing a traditional LA or the StemRad MD radiation protection system. Total fluoroscopy time, procedure type, and ergonomic risk postures were recorded and analyzed. RESULTS: Twenty-one cases were performed with StemRad MD and 30 with LAs. Mean procedure time for the StemRad MD procedures was 48.4±23.3 minutes (range: 24-106 min), and for LA procedures, it was 34.66±25.83 minutes (range: 6-100 min) (p=.060). The operators assumed low-risk ergonomic positions in 96.1% of StemRad MD cases and in 62.9% of LA cases (p=.001), and high-risk ergonomic positions in 0% and 6.2%, respectively (p=.80). Mean EPR score for StemRad MD was 1.16, and for the LA, it was 1.49 (p=.001). CONCLUSIONS: StemRad MD significantly reduces the EPR to the torso compared with a LA-based radiation protection system. CLINICAL IMPACT: Poor ergonomic posture during interventional procedures might leas to work-related musculoskeletal disorders for healthcare workers. StemRad MD, a weightless, exoskeleton-based radiation protection system was shown to significantly reduce ergonomic posture risk to the torso compared to conventional lead aprons. This might lead to reduced physical discomfort for procedure-based specialists.

Objective Evaluation of Clock Face Suture Using the Objective Structured Assessment of Technical Skill (OSATS) Checklist.

Objective: Assessment of the quality of the final product (QFP) is critical in simulation training, such as the clock face suture (CFS) exercise that is used to assess trainees' needle handling and suturing accuracy. Objective Structured Assessment of Technical Skill (OSATS) scores are the gold standard for the evaluation of trainees. The aim was to investigate variability in the use of OSATS checklists and to evaluate a semi-automatic method of suture analysis vs. OSATS scores. Methods: Details of 287 CFSs performed by trainees during Fundamentals in Vascular Surgery examinations were collected. All were rated according to a seven item OSATS checklist, including QFP score and an overall score by one or two expert surgeons immediately after completion. Interassessor variability was assessed for the CFS that were assessed by two assessors.In order to assess intra- and interassessor variability, 50 CFS pictures were chosen randomly and submitted to three expert surgeons to rate the QFP twice and to carry out a semi-automatic image analysis of each CFS and the estimated cumulative error (CE; mm) recorded. It was hypothesised that the CE correlates to OSATS checklist items or overall score. Variables were compared for correlation with OSATS results using a linear regression. A Pearson's test was used to confirm the proposed hypothesis. Results: Mean ± standard deviation overall score for the OSATS checklist was 20.61 ± 6.33. Inter- and intra-assessor correlation were statistically significant regarding OSATS checklist items. Both correlations presented a low coefficient of determination, indicating variability. The mean CE was 16.07 ± 4.84 mm, and the correlation between the QFP and CE was statistically significant, proving that CE is an objective metric by which to assess the QFP. Conclusion: OSATS score demonstrated intra- and interassessor variability, although there was a significant correlation between scores. CE is an objective metric that is not subject to assessor subjectivity or interassessor variability and is correlated with the gold standard of evaluation.

Endovascular Porcine Model of Iliocaval Venous Thrombosis.

OBJECTIVE: To develop a large animal model of iliocaval deep venous thrombosis (DVT), which enables development and evaluation of interventional management and existing imaging modalities. METHODS: The experimental protocol consisted of a total endovascular approach. Pigs were percutaneously accessed through the right internal jugular and bilateral femoral veins. Three balloon catheters were inflated to induce venous stasis in the infrarenal inferior vena cava (IVC) and bilateral common iliac veins (CIVs). Hypercoagulability was induced by injecting 10 000 IU of thrombin. After 2.5 hours, the balloon catheters were removed before animal recovery. After seven, 14, 21, 28, or 35 days, animals were euthanised; the IVC and CIV were harvested en bloc, cross sectioned and prepared for histological examination. Multimodal imaging was performed before and after thrombus creation, and before animal euthanasia. RESULTS: Thirteen female domestic pigs with a mean weight of 59.3 kilograms were used. The mean maximum IVC diameter and area were 16.4 mm and 1.2 cm2, respectively. The procedure was successful in 12 animals with occlusive venous thrombosis in the region of interest on immediate post-operative magnetic resonance venography and a mean thrombus volume of 19.8 cm3. Clinical pathology results showed platelet consumption, D dimer increase, and inflammatory response. Histological evaluation demonstrated a red cell, fibrin, and platelet rich thrombus on day 1, with progressive inflammatory cell infiltration from day 7. Collagen deposition appeared in week 2 and neovascularisation in week 3. CONCLUSION: Endovascular occlusion combined with thrombin infusion is a reliable minimally invasive approach to produce acute and subacute DVT in a large animal model.

COVID-19 and aortic disease: a practical systematic review of the literature on management and outcomes.

INTRODUCTION: Since the outbreak of the 2019 coronavirus (COVID-19), vascular specialists have faced dramatic changes in clinical and surgical practice. Although COVID-19 pulmonary signs and symptoms were the most pertinent problems initially, in the long term, cardiovascular complications became the most fearsome, with poor outcomes in terms of morbidity and mortality. Algorithms and decision-making procedures have been modified, not only to treat new clinical findings in COVID-19 positive patients, but also to avoid complications related to pulmonary and systemic infections. Additionally, COVID-19-negative patients experienced challenging management, due to hospital crowding, the risk of nosocomial COVID-19 transmission, and pandemic emergencies. In this context, aortic interventions were subject to several difficulties. First, in COVID-19-positive patients, there was the onset of new pathological scenarios including thrombotic manifestations and the subsequent complications. Second, in both COVID-19-negative and positive patients, there was a need to deliver optimal treatment with acceptable perioperative risks, forcing a rethinking of decision-making especially in terms of indications for treatments. The aim of this systematic review is to present evidence published on COVID-19 and aortic-related issues, highlighting some challenging aspects regarding management, treatment and outcomes. EVIDENCE ACQUISITION: Data search was performed on PubMed, Scopus and Web of Science, using as time range "January 1st, 2000 - May 1st, 2021." Only articles in English language were included. Key words used for the query were "Aorta" AND "COVID-19" OR "SARS-CoV-2." Furthermore, the NCBI database of "SARS-CoV-2 Resources" was interrogated to find further relevant studies. EVIDENCE SYNTHESIS: The search retrieved 416 papers; among these, 46 studies were eligible and reviewed in depth. The published literature suggests the existence of a hypercoagulable state in patients with COVID-19 disease occurring via direct and indirect mechanisms. COVID-19 infection seems to promote a prothrombotic status that aggravates vascular disease. Regardless of clinical laboratory or status, active COVID-19 infection is considered a risk factor for poor vascular surgery outcomes. Specifically, it is associated with a fourfold increased risk of death and a threefold increased risk of major adverse events. Prognosis of patients hospitalized with COVID-19 disease is often determined by the extent of pulmonary disease, although vascular complications also greatly affect outcomes. Nevertheless, although COVID­19 is highly morbid, in high­risk operations good outcomes can still be achieved even in elderly patients with COVID­19. CONCLUSIONS: In the case of aortic disease during active COVID-19 infection, poor outcomes are associated with COVID-19 vascular and non-vascular complications, while for COVID-19-negative patients not much changed in terms of outcomes, despite the difficulties in management. Endovascular repair, when possible, minimized the impact of treatment, reducing the risk of COVID-related postoperative complications or acquired infection in negative patients.

Evaluating a Novel Telescoping Catheter Set for Treatment of Central Venous Occlusions.

BACKGROUND: Central venous occlusive disease (CVOD) is a prevalent problem in patients with end-stage renal disease (ESRD) and can lead to access malfunction or ligation for symptomatic relief. The purpose of this study is to evaluate the efficacy of the TriForce® Peripheral Crossing Set (Cook Medical), a novel reinforced telescoping catheter set designed to provide additional support for crossing difficult central venous occlusions. METHODS: This is a single-center retrospective study from a quaternary referral center. We identified 37 patients over a 17-month period who underwent 56 attempts at endovascular recanalization for the treatment of central venous occlusion. Technical success rates, procedural data, and outcomes were compared between those undergoing recanalization using traditional wire/catheter sets versus the TriForce catheter set. RESULTS: Average age was 48 ± 2 years. Comorbidities were similar between the two cohorts and included ESRD (61%), deep venous thrombosis (30%), and May-Thurner syndrome (7%). Forty attempts were made with traditional wire/catheter sets and 16 attempts with the TriForce catheter set to treat 2.1 ± 0.2 and 1.9 ± 0.3 occluded venous segments, respectively (P = 0.74). Technical success rates were significantly higher for the group undergoing recanalization using the TriForce catheter (69% versus 38%, P = 0.04) and 4 patients were successfully recanalized using the TriForce catheter set after a failed attempt with traditional wire/catheter sets. Mean fluoroscopy time and radiation dose were 13 ± 3 min and 14,623 ± 2,775 µGy∗m2 for traditional techniques versus 30 ± 6 min and 30,408 ± 10,433 µGy∗m2 for the novel telescoping catheter set (P = 0.01 and 0.09, respectively). Freedom from reintervention at 1 year was 60% for the TriForce cohort versus 44% for the traditional wire/catheter cohort (P = 0.25). CONCLUSIONS: The novel TriForce reinforced telescoping catheter set is a useful adjunct that may improve recanalization rates of CVOD compared with traditional wire/catheter sets.

Important longitudinal and circumferential pulsatile changes in zone 0 of the aorta during the cardiac cycle.

OBJECTIVES: Correct stent-graft sizing is important when planning for thoracic endovascular repair in zone 0. As the movements of the aorta are constantly evolving in longitudinal and circumferential directions during the cardiac cycle, the diameter may not be the only important measurement. The aim of this study is to measure the circumferential and longitudinal pulsatile changes throughout the cardiac cycle. METHODS: Ninety-two patients, who were evaluated for transcatheter aortic valve replacement, were selected for this retrospective study. Their electrocardiogram-gated cardiac computed tomography was analysed. We identified the area, perimeter and diameter of the thoracic aorta in zone 0 and calculated the differences between these parameters at 3 locations in zone 0. The measurements were made in multiplanar views perpendicular to the semi-automatically created centreline in both systolic and diastolic phases. RESULTS: The mean age of our study cohort was 77 ± 11 years. The mean change between systole and diastole of the area (mm2), perimeter (mm) and diameter (mm) were compared at 3 different locations in the ascending aorta: at the sinotubular junction (0.78 mm2 vs 0.89 mm vs 1.41 mm), mid-ascending (0.72 mm2 vs 0.68 vs 0.81 mm) and proximal edge of the brachiocephalic artery (0.76 mm2 vs 0.73 mm vs 0.73 mm). The change in percentage is the smallest in the area at the sinotubular junction compared to the perimeter and diameter (2.6% vs 3.1% vs 4.7%). CONCLUSIONS: Changes in measurement of ascending aortic diameter with cardiac cycle are larger than measurement change in the area. This is especially more pronounced in zone 0A. For more accurate information on the morphometric changes, it may be necessary to measure the area when planning for thoracic endovascular repair to maximize results. A prospective study comparing these different measurements regarding the outcomes is advised by the authors to understand the clinical implications.

Critical Review of Large Animal Models for Central Deep Venous Thrombosis.

OBJECTIVE: To review the existing literature on large animal models of central venous thrombosis (CVT) and to evaluate its relevance in regard to the development and testing of dedicated therapeutics applicable to humans. METHODS: A systematic literature search was conducted in PubMed and Embase. Articles describing an in vivo experimental protocol of CVT in large animals, involving the iliac vein and/or the vena cava and/or the brachiocephalic vein, were included. The primary aim of the study, animal characteristics, experimental protocol, and thrombus evaluation were recorded. RESULTS: Thirty-eight papers describing more than 30 different protocols were included. Animals used were pigs (53%), dogs (21%), monkeys (24%), and cattle (3%). The median number of animals per study was 12. Animal sex, strain, and weight were missing in 18 studies (47%), seven studies (18%), and eight studies (21%), respectively. CVT was always induced by venous stasis: solely (55%), or in addition to hypercoagulability (37%) or endothelial damage (10%). The size of the vessel used for thrombus creation was measured in four studies (10%). Unexpected animal death occurred in nine studies (24%), ranging from 3% to 37% of the animals. Twenty-two studies (58%) in the acute phase and 31 studies in the chronic phase (82%) evaluated the presence or absence of the thrombus created, and its occlusive characteristic was reported, respectively, in five and 17 studies. Histological examination was performed in 24 studies (63%) with comparison to human thrombus in one study. CONCLUSION: This review showed advantages and weaknesses of the existing large animal models of CVT. Future models should insist on more rigour and consistency in reporting animal characteristics, as well as evaluating and comparing the thrombus created to human thrombus.

Balloon-Assisted Ultrasound-Guided Percutaneous Thrombin Injection of Iatrogenic Femoral Artery Pseudoaneurysms: A Case Report and Description of the Technique.

Ultrasound-guided thrombin injection (UGTI) has emerged as the first-line treatment for moderately sized or persistent pseudoaneurysms (PSAs). Although rare, the most feared complication of UGTI is arterial thrombosis or embolism during the off-label injection of thrombin causing acute limb ischemia requiring emergent surgical intervention. Higher thrombin volume, rapidity of injection, and wide or short-neck PSAs are all thought to increase the risk of arterial thrombosis or embolism during this procedure. For patients with unfavorable PSA anatomy who are high-risk surgical candidates due to their medical comorbidities or active critical illness, balloon-assisted thrombin injection (BATI) has been suggested as a means to potentially reduce the risk of thrombosis or distal embolization associated with UGTI. This minimally invasive technique also decreases the risk of groin wound dehiscence or infection associated with open repair, especially in patients who are morbidly obese or have had prior groin surgery. We report a patient with a complex femoral artery PSA after endovascular intervention who was successfully treated with BATI and describe the procedure in detail.

In the Fundamentals of Endovascular and Vascular Surgery model motion metrics reliably differentiate competency.

OBJECTIVE: The Fundamentals of Endovascular and Vascular Surgery, a curriculum that includes an endovascular model for skills testing, aims to differentiate between competent and noncompetent performers. The aim of our study was to further validate the model and to test its reliability in assessing the performance of endovascular trainees in an uncontrolled setting. METHODS: The model was tested exclusively in a virtual reality environment. On the basis of their endovascular experience, 52 participants were divided into three groups: novice (<50 endovascular cases), intermediate (50-500 endovascular cases), and expert (>500 endovascular cases). Performance was evaluated in four tasks, measuring the tool tip position and velocity on the virtual model. Average tool tip velocity and movement smoothness in the velocity frequency domain are validated parameters defining proficiency of movement. The data were filtered and interpolated to calculate the metrics. Trials containing critical tool manipulation errors were excluded. RESULTS: In total, 52 tasks completed by novices, 25 completed by intermediates, and 38 completed by experts were analyzed to determine performance. The difference in performance between the novice and expert groups was statistically significant for guidewire smoothness (P < .001). The expert group had a statistically significantly higher average guidewire velocity compared with the novice group (P < .001). CONCLUSIONS: The Fundamentals of Endovascular and Vascular Surgery model continues to differentiate novices from experts on the basis of their handling of guidewire and catheter tools, measured as smoothness and velocity. This model offers a useful instrument to test competency of endovascular surgeons.

Impact of Aortic Tortuosity on Displacement Forces in Descending Thoracic Aortic Aneurysms.

OBJECTIVE: As elastin fibres in the aorta deteriorate with age, the descending thoracic aorta (DTA) becomes longer and more tortuous. In patients with DTA aneurysms, this increased tortuosity may result in a hostile haemodynamic environment for thoracic endovascular aortic repair (TEVAR). The objective of this study was to analyse how increased tortuosity affects haemodynamic displacement forces (DFs) in different segments of the DTA in patients with DTA aneurysms (DTAAs). METHODS: Thirty patients with DTAAs were selected to form three equal groups based on the maximum tortuosity of their DTA: low < 30°, moderate 30°-60°, and high > 60°. Computational fluid dynamics simulations were performed to calculate DFs in all patients. Image based segmentations were carried out to create patient specific models of the aortic geometry. When physiological simulation results were obtained, the haemodynamic DFs on the aortic wall were calculated in four segments of the DTA (zones 4A - D). To enable comparison of DFs in different segments, the DF was normalised by the aortic wall surface area, the equivalent surface traction (EST). RESULTS: The mean age was 73 years, with 67% male. In zone 4C, where most tortuosity occurs, the EST in patients with high tortuosity was more than three times higher, than those with low tortuosity (low, 743 N/m2; moderate, 956 N/m2; high, 2294 N/m2; p = .004). These differences could be attributed to the higher sideways components of the DF vectors, which were more than two times greater in patients with high tortuosity than in patients with low or moderate tortuosity (low, 5.01 N; moderate, 5.50 N; high, 13.21 N; p = .009). CONCLUSION: High tortuosity results in increased displacement forces in the distal segments of the DTA. These forces should be taken into account when planning for TEVAR, as potentially they increase the risk of stent graft related complications, such as migration and endoleak.

Type 1b Endoleaks After Thoracic Endovascular Aortic Repair are Inadequately Reported: A Systematic Review.

BACKGROUND: Complications after thoracic endovascular aortic repair (TEVAR) are common. Even after a successful TEVAR, a late endoleak (>30 days) can occur. The objective of this study is to summarize the current evidence and, if lacking, the need of evidence regarding the incidence and predictive factors for type 1b endoleak in patients with aortic aneurysm treated with TEVAR. METHODS: A systematic review of the literature was performed on endoleak type 1b, in patients with aortic aneurysm, after TEVAR. The PubMed and Embase databases were systematically searched for articles regarding endoleak type 1b up to January 2019. The main subjects discussed are the incidence, risk factors, treatment, and prognosis. RESULTS: About 722 articles were screened, and 16 articles were included in this review. The reported incidence of endoleak is between 1.0% and 15.0%, with a mean follow-up duration of at least 1 year. Type 1b endoleak is associated with an increased aortic tortuosity index (>0.15 cm-1). No significant difference is found in relation to age and gender. Treatment is required in most cases (22/27) and is usually performed with distal extension of the stent graft (21/27). There are no data regarding stent graft oversizing, length of distal landing zone, and differences between devices or the prognosis for patients with type 1b endoleak. CONCLUSIONS: Limited literature is available on the occurrence of type 1b endoleak after TEVAR. A tortuous aorta can be associated as a predictive factor for the occurrence of type 1b endoleak. Data clearly delineating the anatomic variables predicting type 1b endoleak should be examined and listed. Likewise, the impact of more recent conformable devices to prevent complications like type 1b endoleaks from occurring should be elucidated.

Impact of Cardiac Cycle on Thoracic Aortic Geometry-Morphometric Analysis of Ecg Gated Computed Tomography.

BACKGROUND: Understanding morphological changes of ascending aorta, aortic arch and descending aorta with cardiac and respiratory motion is critical for planning of endovascular repair of thoracic aorta. The aim of this study was to determine the impact of the cardiac cycle on thoracic aortic geometry. METHODS: In this retrospective study, electrocardiogram-gated cardiac computed tomography from 116 patients who were evaluated for transcatheter aortic valve replacement were reviewed. A protocol for measurements of maximal diameters and lengths of the thoracic aorta and supra-aortic vessels was established. Measurements were made in multiplanar views perpendicular to the semiautomatically created centerline on both systolic and diastolic phases. RESULTS: Mean age was 77 ± 11 years of our study cohort. Mean systolic and diastolic diameter were 31.6 ± 0.42 and 30.1 ± 4.4 mm at the sinotubular junction (STJ), 35.6 ± 4.8 and 34.8 ± 4.7 mm in the ascending aorta, 29.1 ± 3.3 and 28.5 ± 3.3 mm in the aortic arch (distal left common carotid artery), and 26.7 ± 5.4 and 25.8 ± 5.4 mm in the descending aorta. Mean diameter change was 1.5 ± 0.9 mm at the STJ, 0.8 ± 0.9 mm in the ascending aorta, 0.6 ± 0.8 mm in the aortic arch, and 0.9 ± 1.2 mm in the descending aorta. Mean arterial strain was 5.0 ± 3.2% at the level of the STJ, 2.4 ± 2.7% in the ascending aorta, 2.0 ± 2.9% in the aortic arch, and 3.9 ± 5.7% in the descending aorta. CONCLUSIONS: Our results demonstrated that small but significant circumferential and longitudinal strain was present at every aortic level. These findings may have implications for endovascular thoracic aortic repair and may provide reference values for future comparison.

Tortuosity of the Descending Thoracic Aorta in Patients with Aneurysm and Type B Dissection.

OBJECTIVE: Tortuosity in the descending thoracic aorta (DTA) comes with aging and increases the risk of endoleaks after TEVAR. With this report, we would like to define and classify tortuosity in the DTA of patients with thoracic aortic disease. METHODS: Retrospective case-control study of two hundred seven patients, comparing sixty-nine controls without aortic disease (CG), to sixty-nine patients with descending thoracic aortic aneurysm (AG) and sixty-nine patients with type B aortic dissection (DG). 3Mensio Vascular software was used to analyze CTA scans and collect the following measurements; tortuosity index, curvature ratio and the maximum tortuosity of the DTA. The DTA was divided into four equal zones. The maximum tortuosity was divided into three groups: low (<30°), moderate (30°-60°) and high tortuosity (>60°). RESULTS: Compared to the CG, tortuosity was more pronounced in the DG, and even more in the AG, evidenced by the tortuosity index (1.11 vs. 1.20 vs. 1.31; p < 0.001), curvature ratio (1.00 vs. 1.01 vs. 1.03; p < 0.001), maximum tortuosity in degrees (28.17 vs. 33.29 vs. 43.83; p < 0.001) and group of tortuosity (p < 0.001). The maximum tortuosity was further distal for the DG and AG, evidenced by the zone of maximum tortuosity (4A vs. 4B vs. 4B; p < 0.001). CONCLUSION: This study shows that tortuosity in the DTA is more prominent in diseased aortas, especially in aneurysmal disease. This phenomenon needs to be taken into account during planning of TEVAR to prevent stent graft-related complications and to obtain positive long-term outcome.