A risk-adjusted and anatomically stratified cohort comparison study of open surgery, endovascular techniques and medical management for juxtarenal aortic aneurysms-the UK COMPlex AneurySm Study (UK-COMPASS): a study protocol.

INTRODUCTION: In one-third of all abdominal aortic aneurysms (AAAs), the aneurysm neck is short (juxtarenal) or shows other adverse anatomical features rendering operations more complex, hazardous and expensive. Surgical options include open surgical repair and endovascular aneurysm repair (EVAR) techniques including fenestrated EVAR, EVAR with adjuncts (chimneys/endoanchors) and off-label standard EVAR. The aim of the UK COMPlex AneurySm Study (UK-COMPASS) is to answer the research question identified by the National Institute for Health Research Health Technology Assessment (NIHR HTA) Programme: 'What is the clinical and cost-effectiveness of strategies for the management of juxtarenal AAA, including fenestrated endovascular repair?' METHODS AND ANALYSIS: UK-COMPASS is a cohort study comparing clinical and cost-effectiveness of different strategies used to manage complex AAAs with stratification of physiological fitness and anatomical complexity, with statistical correction for baseline risk and indication biases. There are two data streams. First, a stream of routinely collected data from Hospital Episode Statistics and National Vascular Registry (NVR). Preoperative CT scans of all patients who underwent elective AAA repair in England between 1 November 2017 and 31 October 2019 are subjected to Corelab analysis to accurately identify and include every complex aneurysm treated. Second, a site-reported data stream regarding quality of life and treatment costs from prospectively recruited patients across England. Site recruitment also includes patients with complex aneurysms larger than 55 mm diameter in whom an operation is deferred (medical management). The primary outcome measure is perioperative all-cause mortality. Follow-up will be to a median of 5 years. ETHICS AND DISSEMINATION: The study has received full regulatory approvals from a Research Ethics Committee, the Confidentiality Advisory Group and the Health Research Authority. Data sharing agreements are in place with National Health Service Digital and the NVR. Dissemination will be via NIHR HTA reporting, peer-reviewed journals and conferences. TRIAL REGISTRATION NUMBER: ISRCTN85731188.

Patient Views on Surgeon-specific Outcome Reporting in Vascular Surgery: Novel Validated Patient Questionnaire Study.

BACKGROUND: SSMD are used to enhance transparency, improve quality and facilitate patient choice. The use of SSMD is controversial, but patients' views on such data are largely unknown. OBJECTIVES: The aim of this study was therefore to explore the views of patients and to identify their priorities for outcome reporting in vascular surgery. METHODS: A prospective questionnaire study of 165 patients receiving care in a single academic vascular unit was performed. Data on patients' current understanding and use of SSMD, together with future priorities were collected. RESULTS: Of the 165 patients 80% were unaware of SSMD. 72% thought they should be made aware of the data, although 63% thought they were likely to misinterpret the results. The majority recognized the utility of SSMD to inform treatment (60%) and surgeon (53%) choice. The majority prioritize the patient-surgeon relationship (90%) and past experiences of care (71%) when making treatment decisions. A significant majority (66% vs 49%; P < 0.005) would favour hospital-level to surgeon-level data. The main patient priorities for future outcome reporting were waiting list length (56%), the quality of hospital facilities (55%), and patient satisfaction (54%). CONCLUSIONS: The aims of SSMD reporting are not currently being met, and both patients and healthcare professionals have shared concerns over the nature and usefulness of the data. Patients express a preference for hospital-level outcomes and prioritize the experience of receiving care over outcomes when making treatment decisions. Future outcome reporting should include patient-directed hospital-level metrics that are readily accessible and understood by all.

Wearable technology-based metrics for predicting operator performance during cardiac catheterisation.

INTRODUCTION: Unobtrusive metrics that can auto-assess performance during clinical procedures are of value. Three approaches to deriving wearable technology-based metrics are explored: (1) eye tracking, (2) psychophysiological measurements [e.g. electrodermal activity (EDA)] and (3) arm and hand movement via accelerometry. We also measure attentional capacity by tasking the operator with an additional task to track an unrelated object during the procedure. METHODS: Two aspects of performance are measured: (1) using eye gaze and psychophysiology metrics and (2) measuring attentional capacity via an additional unrelated task (to monitor a visual stimulus/playing cards). The aim was to identify metrics that can be used to automatically discriminate between levels of performance or at least between novices and experts. The study was conducted using two groups: (1) novice operators and (2) expert operators. Both groups made two attempts at a coronary angiography procedure using a full-physics virtual reality simulator. Participants wore eye tracking glasses and an E4 wearable wristband. Areas of interest were defined to track visual attention on display screens, including: (1) X-ray, (2) vital signs, (3) instruments and (4) the stimulus screen (for measuring attentional capacity). RESULTS: Experts provided greater dwell time (63% vs 42%, p = 0.03) and fixations (50% vs 34%, p = 0.04) on display screens. They also provided greater dwell time (11% vs 5%, p = 0.006) and fixations (9% vs 4%, p = 0.007) when selecting instruments. The experts' performance for tracking the unrelated object during the visual stimulus task negatively correlated with total errors (r = - 0.95, p = 0.0009). Experts also had a higher standard deviation of EDA (2.52 µS vs 0.89 µS, p = 0.04). CONCLUSIONS: Eye tracking metrics may help discriminate between a novice and expert operator, by showing that experts maintain greater visual attention on the display screens. In addition, the visual stimulus study shows that an unrelated task can measure attentional capacity. Trial registration This work is registered through clinicaltrials.gov, a service of the U.S. National Health Institute, and is identified by the trial reference: NCT02928796.

An Evaluation of the Impact of High-Fidelity Endovascular Simulation on Surgeon Stress and Technical Performance.

OBJECTIVE: To measure the physiological stress response associated with high-fidelity endovascular team simulation. DESIGN: This is a prospective cohort study. SETTING: This study was performed at St Mary's Hospital (Imperial College London, London, UK), in a tertiary setting. PARTICIPANTS: Thirty-five participants (10 vascular surgical residents, 4 surgical interns, 12 theatre nurses, 2 attending vascular surgeons, 6 medical students and 1 technician) were recruited from the Imperial Vascular Unit at St Mary's Hospital, Imperial College London by direct approach. All participants finished the study. RESULTS: Junior surgeons experienced significantly increased sympathetic tone (Low frequency/high frequency (LF/HF) ratio) during team simulation compared to individual simulation (6.01 ± 1.68 vs. 8.32 ± 2.84, p < 0.001). Within team simulation junior surgeons experienced significantly higher heart rate (beats per minute) than their senior counterparts (82 ± 5.83 vs. 76 ± 6.02, p = 0.033). Subjective workload scores (NASA Task Load Index [NASA-TLX]) correlated moderately and significantly with sympathetic tone in surgeons across all stages of simulation. (r = 0.39, p = 0.01). CONCLUSIONS: A discrete, measurable increase in stress is experienced by surgeons during high-fidelity endovascular simulation and differentially effects junior surgeons. High-fidelity team simulation may have a role to play in improving nontechnical skill, reducing intra-operative stress, and reducing error.

The use of video motion analysis to determine the impact of anatomic complexity on endovascular performance in carotid artery stenting.

OBJECTIVE: Video motion analysis (VMA) uses fluoroscopic sequences to derive information on catheter and guidewire movement and is able to calculate two-dimensional catheter tip path length (PL) on the basis of frame-by-frame pixel coordinates. The objective of this study was to evaluate the effect of anatomic complexity on the efficiency of completion of defined stages of simulated carotid artery stenting as measured by VMA. METHODS: Twenty interventionists each performed a standardized easy, medium, and difficult carotid artery stenting case in random order on an ANGIO Mentor (Simbionix, Airport City, Israel) simulator. Videos of all procedures were analyzed using VMA software, and performance was expressed in terms of two-dimensional guidewire tip trajectory distance (PL). Comparisons of PL were used to identify differences in cannulation performance of the participants between the three cases of varying difficulty. The procedure was subdivided into four procedural phases: arch navigation, common carotid artery (CCA) cannulation, external carotid manipulation, and carotid lesion crossing. Comparisons of PL were used to identify differences in performance between the three cases of varying difficulty for each of the procedural phases. RESULTS: There were significant differences in PL in relation to anatomic complexity, with a stepwise increase in PL from easy to difficult cases: easy, median of 5000 pixels (interquartile range, 4075-5403 pixels); intermediate, 9059 (5974-14,553) pixels; difficult, 17,373 (11,495-26,594) pixels (P < .001). Similarly, during CCA cannulation, there was a stepwise increase in PL from easy to difficult cases: easy, 749 (603-1403) pixels; intermediate, 3274 (1544-8142) pixels; difficult, 8845 (5954-15,768) pixels (P < .001). There were no observed differences across the groups of anatomic difficulty for the phases of arch navigation, external carotid manipulation, and carotid lesion crossing. CONCLUSIONS: Increasing anatomic complexity leads to significant increases in PL of endovascular tools, in particular during CCA cannulation. This increase in tool movement may have a bearing on clinical outcome.

Flexible robotic catheters in the visceral segment of the aorta: advantages and limitations.

Flexible robotic catheters are an emerging technology which provide an elegant solution to the challenges of conventional endovascular intervention. Originally developed for interventional cardiology and electrophysiology procedures, remotely steerable robotic catheters such as the Magellan system enable greater precision and enhanced stability during target vessel navigation. These technical advantages facilitate improved treatment of disease in the arterial tree, as well as allowing execution of otherwise unfeasible procedures. Occupational radiation exposure is an emerging concern with the use of increasingly complex endovascular interventions. The robotic systems offer an added benefit of radiation reduction, as the operator is seated away from the radiation source during manipulation of the catheter. Pre-clinical studies have demonstrated reduction in force and frequency of vessel wall contact, resulting in reduced tissue trauma, as well as improved procedural times. Both safety and feasibility have been demonstrated in early clinical reports, with the first robot-assisted fenestrated endovascular aortic repair in 2013. Following from this, the Magellan system has been used to successfully undertake a variety of complex aortic procedures, including fenestrated/branched endovascular aortic repair, embolization, and angioplasty.

Surgeons' Perceptions of the Causes of Preventable Harm in Arterial Surgery: A Mixed-Methods Study.

BACKGROUND: System factors contributing to preventable harm in vascular patients have not been previously reported in detail. The aim of this exploratory mixed-methods study was to describe vascular surgeons' perceptions of factors contributing to adverse events (AEs) in arterial surgery. A secondary aim was to report recommendations to improve patient safety. METHODS: Vascular consultants/registrars working in the British National Health Service were questioned about the causes of preventable AEs through survey and semi-structured interview (response rates 77% and 83%, respectively). Survey respondents considered a recent AE, indicating on a 5 point Likert scale the extent to which various factors from a validated framework contributed toward the incident. Semi-structured interviews were conducted to obtain detailed accounts of contributory factors, and to elicit recommendations to improve safety. RESULTS: Seventy-seven surgeons completed the survey on 77 separate AEs occurring during open surgery (n = 41) and in endovascular procedures (n = 36). Ten interviewees described 15 AEs. The causes of AEs were multifactorial (median number of factors/AE = 5, IQR 3-9, range 0-25). Factors frequently reported by survey respondents were communication failures (36.4%; n = 28/77); inadequate staffing levels/skill mix (32.5%; n = 25/77); lack of knowledge/skill (37.3%; n = 28/75). Themes emerging from interviews were team factors (communication failure, lack of team continuity, lack of clarity over roles/responsibilities); work environment factors (poor staffing levels, equipment problems, distractions); inadequate training/supervision. Knowledge/skill (p = .034) and competence (p = .018) appeared to be more prominent in causing AEs in open procedures compared with endovascular procedures; organisational structure was more frequently implicated in AEs occurring in endovascular procedures (p = .017). To improve safety, interviewees proposed team training programmes (5/10 interviewees); additional protocols/checklists (4/10); improved escalation procedures (3/10). CONCLUSION: Vascular surgeons believe that AEs in arterial operations are caused by multiple, modifiable system factors. Larger studies are needed to establish the relative importance of these factors and to determine strategies that can effectively address system failures.

Patient-specific Rehearsal Before EVAR: Influence on Technical and Nontechnical Operative Performance. A Randomized Controlled Trial.

OBJECTIVE: To assess the effect of patient-specific virtual reality rehearsal (PsR) before endovascular infrarenal aneurysm repair (EVAR) on technical performance and procedural errors. BACKGROUND: Endovascular procedures, including EVAR, are executed in a complex multidisciplinary environment, often treating high-risk patients. Consequently, this may lead to patient harm and procedural inefficiency. PsR enables the endovascular team to evaluate and practice the case in a virtual environment before treating the real patient. METHODS: A multicenter, prospective, randomized controlled trial recruited 100 patients with a nonruptured infrarenal aortic or iliac aneurysm between September 2012 and June 2014. Cases were randomized to preoperative PsR or standard care (no PsR). Primary outcome measures were errors during the real procedure and technical operative metrics (total endovascular and fluoroscopy time, contrast volume, number of angiograms, and radiation dose). RESULTS: There was a 26% [95% confidence interval (CI) 9%-40%, P = 0.004) reduction in minor errors, a 76% (95% CI 30%-92%, P = 0.009) reduction in major errors, and a 27% (95% CI 8.2%-42%, P = 0.007) reduction in errors causing procedural delay in the PsR group. The number of angiograms performed to visualize proximal and distal landing zones was 23% (95% CI 8%-36%, P = 0.005) and 21% (95% CI 7%-32%, P = 0.004) lower in the PsR group. CONCLUSIONS: PsR before EVAR can be used in different hospital settings by teams with various EVAR experience. It reduces perioperative errors and the number of angiograms required to deploy the stent graft, thereby reducing delays. Ultimately, it may improve patient safety and procedural efficiency.

An evaluation of the effect of an angiotensin-converting enzyme inhibitor on the growth rate of small abdominal aortic aneurysms: a randomized placebo-controlled trial (AARDVARK).

AIMS: The AARDVARK (Aortic Aneurysmal Regression of Dilation: Value of ACE-Inhibition on RisK) trial investigated whether ACE-inhibition reduces small abdominal aortic aneurysms (AAA) growth rate, independent of blood pressure (BP) lowering. METHODS AND RESULTS: A three-arm, multi-centre, single-blind, and randomized controlled trial (ISRCTN51383267) was conducted in 14 hospitals in England. Subjects aged ≥55 years with AAA diameter 3.0-5.4 cm were randomized 1:1:1 to receive perindopril arginine 10 mg, or amlodipine 5 mg, or placebo and followed 3-6 monthly over 2 years. The primary outcome was aneurysm growth rate (based on external antero-posterior ultrasound measurements in the longitudinal plane), determined by multi-level modelling to provide maximum likelihood estimates. Two hundred and twenty-four subjects were randomized (2011-2013) to placebo (n = 79), perindopril (n = 73), or amlodipine (n = 72). Mean (SD) changes in mid-trial systolic BP (12 months) were 0.5 (14.3) mmHg, P = 0.78 compared with baseline, -9.5 (13.1) mmHg (P < 0.001), and -6.7 (12.0) mmHg (P < 0.001), respectively. No significant differences in the modelled annual growth rates were apparent [1.68 mm (SE 0.2), 1.77 mm (0.2), and 1.81 mm (0.2), respectively]. The estimated difference in annual growth between the perindopril and placebo groups was 0.08 mm (CI -0.50, 0.65). Similar numbers of AAAs in each group reached 5.5 cm diameter and/or underwent elective surgery: 11 receiving placebo, 10 perindopril, and 11 amlodipine. CONCLUSION: Small AAA growth rates were lower than anticipated, but there was no significant impact of perindopril compared with placebo or placebo and amlodipine, combined despite more effective BP lowering.

Catheter manipulation analysis for objective performance and technical skills assessment in transcatheter aortic valve implantation.

PURPOSE: Transcatheter aortic valve implantation (TAVI) demands precise and efficient handling of surgical instruments within the confines of the aortic anatomy. Operational performance and dexterous skills are critical for patient safety, and objective methods are assessed with a number of manipulation features, derived from the kinematic analysis of the catheter/guidewire in fluoroscopy video sequences. METHODS: A silicon phantom model of a type I aortic arch was used for this study. Twelve endovascular surgeons, divided into two experience groups, experts ([Formula: see text]) and novices ([Formula: see text]), performed cannulation of the aorta, representative of valve placement in TAVI. Each participant completed two TAVI experiments, one with conventional catheters and one with the Magellan robotic platform. Video sequences of the fluoroscopic monitor were recorded for procedural processing. A semi-automated tracking software provided the 2D coordinates of the catheter/guidewire tip. In addition, the aorta phantom was segmented in the videos and the shape of the entire catheter was manually annotated in a subset of the available video frames using crowdsourcing. The TAVI procedure was divided into two stages, and various metrics, representative of the catheter's overall navigation as well as its relative movement to the vessel wall, were developed. RESULTS: Experts consistently exhibited lower values of procedure time and dimensionless jerk, and higher average speed and acceleration than novices. Robotic navigation resulted in increased average distance to the vessel wall in both groups, a surrogate measure of safety and reduced risk of embolisation. Discrimination of experience level and types of equipment was achieved with the generated motion features and established clustering algorithms. CONCLUSIONS: Evaluation of surgical skills is possible through the analysis of the catheter/guidewire motion pattern. The use of robotic endovascular platforms seems to enable more precise and controlled catheter navigation.

Reducing contact forces in the arch and supra-aortic vessels using the Magellan robot.

OBJECTIVE: Conventional catheter manipulation in the arch and supra-aortic trunks carries a risk of cerebral embolization. This study proposes a platform for detailed quantitative analysis of contact forces (CF) exerted on the vasculature, in order to investigate the potential advantages of robotic navigation. METHODS: An anthropomorphic phantom representing a type I bovine arch was mounted and coupled onto a force/torque sensor. Three-axis force readings provided an average root-mean-square modulus, indicating the total forces exerted on the phantom. Each of the left subclavian, left common carotid, and right common carotid arteries was cannulated within a simulated endovascular suite with conventional (n = 42) vs robotic techniques (n = 30) by two operator groups: experts and novices. The procedure path was divided into three phases, and performance metrics corresponding to mean and maximum forces, force impact over time, standard deviation of forces, and number of significant catheter contacts with the arterial wall were extracted. RESULTS: Overall, median CF were reduced from 1.20 N (interquartile range [IQR], 0.98-1.56 N) to 0.31 N (IQR, 0.26-0.40 N; P < .001) for the right common carotid artery; 1.59 N (IQR, 1.11-1.85 N) to 0.33 N (IQR, 0.29-0.43 N; P < .001) for the left common carotid artery; and 0.84 N (IQR, 0.47-1.08 N) to 0.10 N (IQR, 0.07-0.17 N; P < .001) for the left subclavian artery. Robotic navigation resulted in significant reductions for the mean and maximum forces for each procedural phase. Significant improvements were also seen in other metrics, particularly at the target vessel ostium and for the more anatomically challenging procedural phases. Force reductions using robotic technology were evident for both novice and expert groups. CONCLUSIONS: Robotic navigation can potentially reduce CF and catheter-tissue contact points in an in vitro model, by enhancing catheter stability and control during endovascular manipulation.

Leiomyosarcoma of the thoracic aorta in a patient with hypertrophic cardiomyopathy.

We report a case of leiomyosarcoma of the thoracic aorta in a 49-year-old male patient with history of hypertrophic cardiomyopathy. The only presenting symptom was back pain localized under the left scapula with the frequency and severity of the pain increasing with time. Imaging studies detected the presence of an aortic tumor. The tumor was excised en bloc, and an interposition graft was implanted. The histology showed a fully excised grade 3 leiomyosarcoma. This article discusses features of this rare condition.