Early outcomes of patients transferred with ruptured suprarenal aneurysm or dissection.

Objective Despite centralisation of the provision of vascular care, not all areas in England and Wales are able to offer emergency treatment for patients with acute conditions affecting the aorta proximal to the renal arteries. While cardiothoracic centres have made network arrangements to coordinate care for the repair of type A dissections, a similar plan for vascular care is lacking. This study investigates early outcomes in patients with ruptured suprarenal aortic aneurysm or dissection (rSRAD) transferred to a specialist centre. Methods Retrospective observational study over a five-year period (2009-2014) assessing outcomes of patients with ruptured sRAD diagnosed at their local hospital and then transferred to a tertiary centre capable of offering such treatment. Results Fifty-two patients (median age 73 years, 32 male) with rSRAD were transferred and a further four died during transit. The mean distance of patient transfer was 35 miles (range 4-211 miles). One patient did not undergo intervention due to frailty and two died before reaching the operating theatre. A total of 23 patients underwent endovascular repair, 9 hybrid repair and 17 open surgery. Median follow-up was 12 months (range 1-43 months). Complications included paraplegia (n = 3), stroke (n = 2), type IA endoleak (n = 4); 30-day and in-hospital mortality were 16% and 27%. For patients discharged alive from hospital, one-year survival was 67%. Conclusions Although the number of patients with rSRAD is low and those who are transferred alive are a self-selecting group, this study suggests that transfer of such patients to a specialist vascular centre is associated with acceptable mortality rates following emergency complex aortic repair.

Cerebral embolization, silent cerebral infarction and neurocognitive decline after thoracic endovascular aortic repair.

BACKGROUND: Silent cerebral infarction is brain injury detected incidentally on imaging; it can be associated with cognitive decline and future stroke. This study investigated cerebral embolization, silent cerebral infarction and neurocognitive decline following thoracic endovascular aortic repair (TEVAR). METHODS: Patients undergoing elective or emergency TEVAR at Imperial College Healthcare NHS Trust and Guy's and St Thomas' NHS Foundation Trust between January 2012 and April 2015 were recruited. Aortic atheroma graded from 1 (normal) to 5 (mobile atheroma) was evaluated by preoperative CT. Patients underwent intraoperative transcranial Doppler imaging (TCD), preoperative and postoperative cerebral MRI, and neurocognitive assessment. RESULTS: Fifty-two patients underwent TEVAR. Higher rates of TCD-detected embolization were observed with greater aortic atheroma (median 207 for grade 4-5 versus 100 for grade 1-3; P = 0·042), more proximal landing zones (median 450 for zone 0-1 versus 72 for zone 3-4; P = 0·001), and during stent-graft deployment and contrast injection (P = 0·001). In univariable analysis, left subclavian artery bypass (ß coefficient 0·423, s.e. 132·62, P = 0·005), proximal landing zone 0-1 (ß coefficient 0·504, s.e. 170·57, P = 0·001) and arch hybrid procedure (ß coefficient 0·514, s.e. 182·96, P < 0·001) were predictors of cerebral emboli. Cerebral infarction was detected in 25 of 31 patients (81 per cent) who underwent MRI: 21 (68 per cent) silent and four (13 per cent) clinical strokes. Neurocognitive decline was seen in six of seven domains assessed in 15 patients with silent cerebral infarction, with age a significant predictor of decline. CONCLUSION: This study demonstrates a high rate of cerebral embolization and neurocognitive decline affecting patients following TEVAR. Brain injury after TEVAR is more common than previously recognized, with cerebral infarction in more than 80 per cent of patients.

The Impact of System Factors on Quality and Safety in Arterial Surgery: A Systematic Review.

OBJECTIVE: A systems approach to patient safety proposes that a wide range of factors contribute to surgical outcome, yet the impact of team, work environment, and organisational factors, is not fully understood in arterial surgery. The aim of this systematic review is to summarize and discuss what is already known about the impact of system factors on quality and safety in arterial surgery. DATA SOURCES: A systematic review of original research papers in English using MEDLINE, Embase, PsycINFO, and Cochrane databases, was performed according to PRISMA guidelines. REVIEW METHODS: Independent reviewers selected papers according to strict inclusion and exclusion criteria, and using predefined data fields, extracted relevant data on team, work environment, and organisational factors, and measures of quality and/or safety, in arterial procedures. RESULTS: Twelve papers met the selection criteria. Study endpoints were not consistent between papers, and most failed to report their clinical significance. A variety of tools were used to measure team skills in five papers; only one paper measured the relationship between team factors and patient outcomes. Two papers reported that equipment failures were common and had a significant impact on operating room efficiency. The influence of hospital characteristics on failure-to-rescue rates was tested in one large study, although their conclusions were limited to the American Medicare population. Five papers implemented changes in the patient pathway, but most studies failed to account for potential confounding variables. CONCLUSIONS: A small number of heterogenous studies have evaluated the relationship between system factors and quality or safety in arterial surgery. There is some evidence of an association between system factors and patient outcomes, but there is more work to be done to fully understand this relationship. Future research would benefit from consistency in definitions, the use of validated assessment tools, measurement of clinically relevant endpoints, and adherence to national reporting guidelines.

Robotic Arch Catheter Placement Reduces Cerebral Embolization During Thoracic Endovascular Aortic Repair (TEVAR).

OBJECTIVE: Stroke caused by cerebral embolization constitutes a principal risk during arch manipulation and thoracic endovascular aortic repair (TEVAR). This study investigates the incidence of cerebral embolization during catheter placement in the aortic arch, and compares robotic and manual techniques. METHODS: Intra-operative transcranial Doppler (TCD) was performed in 11 patients undergoing TEVAR. Wire and catheter placement in the arch was performed by two experienced operators. Manual and robotic catheter placement and removal were compared for each patient; 44 manoeuvres were studied in total. A conventional 5Fr pigtail catheter was used for manual cannulation via a 5Fr access sheath. The 6Fr/9Fr co-axial Magellan endovascular robotic system was used for robotic navigation operated from a remote workstation. The number of high intensity transient signals (HITS) detected by TCD during different stages of TEVAR was recorded. RESULTS: The median procedural embolization rate was 173 (interquartile range 97-240). There were significantly fewer HITS detected during robotic catheter placement with six in total (median 0, IQR 0-1), compared with 38 HITS (median 2, IQR 1-5) during manual catheter placement (p = .018). There were no HITS detected during robotic catheter removal by auto-retraction as per manufacturer instructions. On two occasions, however, when the robotic catheter system was removed manually without correcting for articulation, it resulted in one HIT in one case and 11 HITS in the second case. CONCLUSIONS: Robotic catheter placement is feasible during TEVAR, and results in significantly less cerebral embolization compared with manual techniques. The active manoeuvrability, control, and stability of the robotic system is likely to reduce contact with an atheromatous aortic arch wall, and thereby reduce dislodgement of particulate matter and result in less embolization. The importance of adhering to manufacturer instructions during use and removal of the robotic catheter is also highlighted.

Long-term results of intra-arterial onyx injection for type II endoleaks following endovascular aneurysm repair.

Purpose The aim of this paper is to report our experience of type II endoleak treatment after endovascular aneurysm repair with intra-arterial injection of the embolizing liquid material, Onyx liquid embolic system. Methods From 2005 to 2012, we performed a retrospective review of 600 patients, who underwent endovascular repair of an abdominal aortic aneurysm. During this period, 18 patients were treated with Onyx for type II endoleaks. Principal findings The source of the endoleak was the internal iliac artery in seven cases, inferior mesenteric artery in seven cases and lumbar arteries in four cases. Immediate technical success was achieved in all patients and no endoleak from the treated vessel recurred. During a mean follow-up of 19 months, no major morbidity or mortality occurred, and one-year survival was 100%. Conclusions Treatment of type II endoleaks with Onyx is safe and effective over a significant time period.

Editor's Choice - Management of Secondary Aorto-enteric and Other Abdominal Arterio-enteric Fistulas: A Review and Pooled Data Analysis.

OBJECTIVES: To compare management strategies for secondary abdominal arterio-enteric fistulas (AEFs). METHODS: This study is a review and pooled data analysis. Medline and Scopus databases were searched for studies published between 1999 and 2015. Particular emphasis was given to short- and long-term outcomes in relation to AEF repair type. RESULTS: Two hundred and sixteen publications were retrieved, reporting on 823 patients. In-hospital mortality was 30.7%. Open surgery had higher in-hospital mortality (246/725, 33.9%), than endovascular methods (7/98, 7.1%, p < .001, OR 6.7, 95% CI 3-14.7, including staged endovascular to open surgery, 0/13, 0%). In-hospital mortality after graft removal/extra-anatomical bypass grafting was 31.2% (66/226), graft removal/in situ repair 34% (137/403), primary closure of the arterial defect 62.5% (10/16), and for miscellaneous open procedures 41.3% (33/80), p = .019. Among the subgroups of in situ repair, homografts were associated with a higher mortality than impregnated prosthetic grafts (p = .047). There was no difference in recurrent AEF-free rates between open and endovascular procedures. Extra-anatomical bypass/graft removal and in situ repair had a lower AEF recurrence rate than primary closure and homografts. Late sepsis occurred more often after endovascular surgery (2-year rates 42% vs. 19% for open, p = .001). The early survival benefit of endovascular surgery was blunted during follow-up, although it remained significant (p < .001). Within the in situ repair group, impregnated prosthetic grafts were associated with the worst overall and AEF related mortality free rates and vein grafts with the best. No recurrence, sepsis, or mortality was reported following staged endograft placement to open repair after a mean follow-up of 16.8 months (p = .18, p = .22, and p = .006, respectively, compared with patients in other groups). CONCLUSIONS: Endovascular surgery, where appropriate, is associated with better early survival than open surgery for secondary AEFs. Most of this benefit is lost during long-term follow-up, implying that a staged approach with early conversion to in situ vein grafting may achieve the best results in selected patients.

Multicentre observational study of surgical system failures in aortic procedures and their effect on patient outcomes.

BACKGROUND: Vascular surgical care has changed dramatically in recent years with little knowledge of the impact of system failures on patient safety. The primary aim of this multicentre observational study was to define the landscape of surgical system failures, errors and inefficiency (collectively termed failures) in aortic surgery. Secondary aims were to investigate determinants of these failures and their relationship with patient outcomes. METHODS: Twenty vascular teams at ten English hospitals trained in structured self-reporting of intraoperative failures (phase I). Failures occurring in open and endovascular aortic procedures were reported in phase II. Failure details (category, delay, consequence), demographic information (patient, procedure, team experience) and outcomes were reported. RESULTS: There were strong correlations between the trainer and teams for the number and type of failures recorded during 88 procedures in phase I. In 185 aortic procedures, teams reported a median of 3 (i.q.r. 2-6) failures per procedure. Most frequent failures related to equipment (unavailability, failure, configuration, desterilization). Most major failures related to communication. Fourteen failures directly harmed 12 patients. Significant predictors of an increased failure rate were: endovascular compared with open repair (incidence rate ratio (IRR) for open repair 0·71, 95 per cent c.i. 0·57 to 0·88; P = 0·002), thoracic aneurysms compared with other aortic pathologies (IRR 2·07, 1·39 to 3·08; P < 0·001) and unfamiliarity with equipment (IRR 1·52, 1·20 to 1·91; P < 0·001). The major failure total was associated with reoperation (P = 0·011), major complications (P = 0·029) and death (P = 0·027). CONCLUSION: Failure in aortic procedures is frequently caused by issues with team-working and equipment, and is associated with patient harm. Multidisciplinary team training, effective use of technology and new-device accreditation may improve patient outcomes.

Contemporary Management of Acute Type B Dissection.

OBJECTIVE: Growing confidence in thoracic endovascular aortic repair (TEVAR) for the management of acute type B aortic dissection has resulted in controversies regarding optimum patient selection and the timing of intervention. In this review a clinical vignette to present a practical perspective on the contemporary management of acute type B dissection (ABAD) in a specialist vascular centre with particular focus on areas of debate is used. METHODS: This is a narrative clinical review. RESULTS: Aggressive anti-impulse therapy is the cornerstone of management of all patients with ABAD. However, 20-30% of patients develop complicated ABAD defined by the presence of malperfusion syndromes, acute aortic dilatation, dissection extension, or persistent pain and hypotension. These complicated patients typically require intervention, and non-randomised series suggest TEVAR to be an effective alternative to open repair with a lower morbidity. There is considerable interest and controversy surrounding the use of TEVAR in uncomplicated ABAD patients for whom the intervention-free survival at 6 years is less than 50% for patients managed with anti-impulse therapy. Data regarding this question are sparse, but two randomised trials (ADSORB and INSTEAD) both demonstrated a higher rate of favourable aortic remodelling in patients managed with TEVAR than medical therapy alone. However, it is unclear whether this positive remodelling translates into a reduction in long-term mortality sufficient to balance the early perioperative hazards of endografting. CONCLUSION: Despite increasing adeptness at endovascular stenting, the long-term outcomes of patients with ABAD leave significant room for improvement. In particular, the optimum management of patients with uncomplicated disease is unclear and guidance from trials powered for long-term mortality is awaited. Until then, the principals of management of ABAD remain aggressive medical therapy for all patients, with TEVAR primarily reserved for those who develop complications.

Treatment decisions for descending thoracic aneurysm: preferences for thoracic endovascular aneurysm repair or surveillance in a discrete choice experiment.

OBJECTIVE: To investigate and rank factors that influence endovascular treatment decisions by specialists for patients with descending thoracic aortic aneurysm (dTAA). METHODS: Specialists completed a diagrammatic survey describing uncertainty about the benefit of thoracic endovascular aneurysm repair (TEVAR) for dTAA with respect to age, sex, and aneurysm diameter. Subsequently, a detailed discrete choice experiment was designed. Specialists were recruited and asked to indicate treatment their preference (TEVAR or surveillance) in 25 hypothetical cases of dTAA, with variable patient attributes: age, sex, American Society of Anesthesiologists (ASA) grade, aneurysm diameter, adequate landing zone distal to left subclavian artery (LSA), and length of aortic coverage. Data were analysed using multiple logistic regression. RESULTS: The diagrammatic survey, based on 50 respondents, showed that uncertainty about the benefits of TEVAR was greatest for patients aged 80-85 years (up to 47% of respondents were "unsure") and that uncertainty increased with increasing aneurysm diameter (for an 80-year-old man, 7% were unsure at 5.5 cm and 33% were unsure at 7.0 cm). Seventy-one specialists (mainly from Europe and North America, 86% vascular surgeons and 98% working in units offering TEVAR) completed the discrete choice experiment. Preference for TEVAR increased greatly with enlarging diameter: adjusted odds ratios (OR) >5.5-6.0 cm = 15.8 (95% confidence interval [CI] 9.83-25.40); >6.0-6.5 cm = 393.0 (95% CI 202.00-766.00); >6.5-7.0 cm = 1829.0 (95% CI 400.00-4,181.00). TEVAR was less likely to be preferred in patients older than 75 years (>75-80 years OR 0.32, 95% CI 0.21-0.49; >80-85 years = 0.18, 95% CI 0.11-0.28); in women (OR 0.52, 95% CI 0.37-0.74); in patients classified as ASA grade 4 (OR 0.44, 95% CI 0.36-0.57); and in patients with aorta coverage >25 cm (OR 0.48, 95% CI 0.32-0.74). The proximal landing zone did not influence preference. CONCLUSION: Specialists' preferences for endovascular repair of degenerative dTAA vary widely, and demonstrate clinical uncertainty, especially in octogenarians, and a reluctance to offer TEVAR to women. Aneurysm diameter dominates treatment preferences, but patient fitness and length of aortic coverage (>25 cm) also were influential, although the landing zone distal to LSA was not.

Planning for EVAR: the role of modern software.

Endovascular intervention has revolutionized the treatment of aortic disease, extending the cohort of patients eligible for repair. Accurate planning for endovascular aortic repair is essential. Recent advances in modern software have demonstrated potential for improving outcomes and enhancing the decision making process beyond 3D measurements and intraoperative navigation techniques. With increasing uptake and complexity of endovascular therapies requiring multidisciplinary collaborations, it has become apparent that planning must extend to the preparation of entire interventional teams and support the early identification and prevention of potentially harmful events. This paper will examine recent advances not only in morphological planning and computational modelling, but also the role of software in the preparation of teams and prevention of error.

Variation in maximum diameter measurements of descending thoracic aortic aneurysms using unformatted planes versus images corrected to aortic centerline.

OBJECTIVE: Evaluation of variation in descending thoracic aortic aneurysm (dTAA) diameters measured on CT scans in different planes and by different observers and the potential impact on treatment decisions. METHODS: CT angiography of dTAA (N = 20) were assessed by three specialists, with measurements repeated after 1 month. Calliper measurements of maximum external diameters were made on unformatted images and perpendicular to the aneurysm centerline after image processing (corrected). Repeatability was assessed using Bland-Altman plots. RESULTS: Maximum corrected diameter measurements were smaller than axial measurements (66.3 ± 7.9 mm vs. 74.9 ± 20.9 mm, p < .001). Both intraobserver and interobserver variation were less for corrected than for axial measurements (mean intraobserver differences 5.0 ± 3.8 mm vs. 11.8 ± 9.3 mm, p < .001; mean interobserver differences 2.8 ± 2.5 mm versus 10.4 ± 14.0 mm, p < .001) and interobserver variation increased with aneurysm diameter for maximum axial but not corrected measurements. Using corrected rather than axial measurements could have changed treatment decisions in two patients (10%) using a treatment threshold diameter of 55 mm and 10 patients (50%) using a threshold of 65 mm. CONCLUSION: Corrected diameters were smaller than axial diameters, could be measured with higher repeatability, and were subject to less interobserver variability. Using corrected versus axial measurements would have changed management decisions in up to half of the cases in this study.

A pilot study of video-motion analysis in endovascular surgery: development of real-time discriminatory skill metrics.

OBJECTIVES: Accurate assessment and credentialing of physicians is essential. Objective motion analysis of guide-wire/catheter manipulation to assess proficiency during endovascular interventions remains unexplored. This study aims to assess its feasibility and its role in evaluation of technical ability. MATERIALS AND METHODS: A semi-automated catheter-tracking software was developed which allows for frame-by-frame motion analysis of fluoroscopic videos and calculation 2D catheter tip path-length. 21 interventionalists (6 cardiologists, 8 interventional radiologists, 7 vascular surgeons; 14/21 had performed >500 endovascular procedures) performed an identical carotid artery stenting procedure (CAS) on a VIST simulator (Mentice, Gothenburg, Sweden). Operators were sub-divided into four categories according to CAS experience: 6 inexperienced (0 CAS-group A), 3 low-volume (1-20 CAS-group B), 5 moderate-volume (21-50 CAS-group C) and 7 high-volume (>50 CAS-group D) CAS experience. Total PL was calculated for each case and comparisons made between groups. PL was correlated with: quantitative, simulator-derived metrics and qualitative performance scores (generic and procedure-specific) derived from post-hoc video analysis by three blinded observers. RESULTS: Group D used 5160.3 (inter-quartile range- IQR 4046.4-7142.9) pixels of movement, compared to 6856.7 (5914.4-8106.9) for group A (p = 0.046); 10,905.1 (7851.1-14,381.5) for group B (p = 0.017); and 9482.6 (8663.5-13,847.6) for group C (p = 0.003). Statistically significant inverse correlations were seen between total PL and qualitative performance scores (rho = -0.519 for generic (p = 0.027) rho = -0.567 for procedure-specific (p = 0.014) scores). PL did not correlate with any of the simulator-derived metrics (errors, contrast volume, total procedure and fluoroscopy times, cine-loops used). CONCLUSION: Endovascular instrument video motion analysis is feasible and may represent a valuable tool for the objective assessment of endovascular skill.

Design and validation of an error capture tool for quality evaluation in the vascular and endovascular surgical theatre.

BACKGROUND: The unique and complex vascular and endovascular theatre environment is associated with significant risks of patient harm and procedural inefficiency. Accurate evaluation is crucial to improve quality. This pilot study attempted to design a valid, reproducible tool for observers and teams to identify and categorise errors. METHODS: Relevant published literature and previously collected ethnographic field notes from over 250 h of arterial surgery were analysed. A comprehensive log of vascular procedural errors was compiled and twelve vascular experts graded each error for the potential to disrupt procedural flow and cause harm. Using this multimodal approach, the Imperial College Error CAPture (ICECAP) tool was developed. The tool was validated during 21 consecutive arterial cases (52 h operating-time) as an observer-led error capture record and as a prompt for surgical teams to determine the feasibility of error self-reporting. RESULTS: Six primary categories (communication, equipment, procedure independent pressures, technical, safety awareness and patient related) and 20 error sub-categories were determined as the most frequent and important vascular procedural errors. Using the ICECAP, the number of errors detected correlated well between two observers (Spearman rho = 0.984, p < 0.001). Both observers identified all moderate or severe errors similarly and categorised all but 4/139 (2.9%) of the total errors in an identical fashion. Self-reporting of errors without prompting identified a mean of 24.4% (range 0-50%) of all recorded errors, whereas surgical teams reported a mean of 69.7% (range 50-100%) of errors when ICECAP error-category prompts were used. CONCLUSION: The ICECAP tool may be useful for capturing and categorising errors that occur during vascular/endovascular procedures. ICECAP may also have a role as an error recall prompt for self-reporting purposes by vascular surgical teams.

Evaluation of an electromagnetic 3D navigation system to facilitate endovascular tasks: a feasibility study.

INTRODUCTION: We describe a novel approach to arterial cannulation using the StealthStation(®) Guidance System (Medtronic, USA). This uses electromagnetic technology to track the guidewire, displaying a 3D image of the vessel and guidewire. METHODS: The study was performed on a 'bench top' simulation model called the Cannulation Suite comprising of a silicone aortic arch model and simulated fluoroscopy. The accuracy of the StealthStation(®) was assessed. 16 participants of varying experience in performing endovascular procedures (novices: 6 participants, ≤5 procedures performed; intermediate: 5 participants, 6-50 procedures performed; experts: 5 participants, >50 procedures performed) underwent a standardised training session in cannulating the left subclavian artery on the model with the conventional method (i.e. with fluoroscopy) and with the StealthStation(®). Each participant was then assessed on cannulating the left subclavian artery using the conventional method and with the StealthStation(®). Performance was video-recorded. The subjects then completed a structured questionnaire assessing the StealthStation(®). RESULTS: The StealthStation(®) was accurate to less than 1 mm [mean (SD) target registration error 0.56 mm (0.91)]. Every participant was able to complete the cannulation task with a significantly lower use of fluoroscopy with the navigation system compared with the conventional method [median 0 s (IQR 0-2) vs median 14 s (IQR 10-19), respectively; p = <0.001]. There was no significant difference between the StealthStation(®) and conventional method for: total procedure time [median 17 s (IQR 9-53) vs median 21 s (IQR 11-32), respectively; p=0.53]; total guidewire hits to the vessel wall [median 0 (IQR 0-1) vs median 0 (IQR 0-1), respectively; p=0.86]; catheter hits to the vessel wall [median 0.5 (IQR 0-2) vs median 0.5 (IQR 0-1), respectively; p=0.13]; and cannulation performance on the global rating scale [median score, 39/40 (IQR 28-39) vs 38/40 (IQR 33-40), respectively; p=0.40]. The intra-class correlation coefficient for agreement between video-assessors for all scores was 0.99. 88% strongly agreed that the StealthStation(®) can potentially decrease exposure of the patient to contrast and radiation. CONCLUSION: Arterial cannulation is feasible with the StealthStation(®).

Advanced catheter technology: is this the answer to overcoming the long learning curve in complex endovascular procedures.

INTRODUCTION: Advanced endovascular procedures require a high degree of skill with a long learning curve. We aimed to identify differential increases in endovascular skill acquisition in novices using conventional (CC), manually steerable (MSC) and robotic endovascular catheters (RC). MATERIALS/METHODS: 10 novices cannulated all vessels within a CT-reconstructed pulsatile-flow arch phantom in the Simulated Endovascular Suite. Subjects were randomly assigned to conventional/manually-steerable/robotic techniques as the first procedure undertaken. The operators repeated the task weekly for 5 weeks. Quantitative (cannulation times, wire/catheter-tip movements, vessel wall hits) and qualitative metrics (validated rating scale (IC3ST)) were compared. RESULTS: Subjects exhibited statistically significant differences when comparing initial to final performance for total procedure times and catheter-tip movements with all catheter types. Sequential non-parametric comparisons identified learning curve plateau levels at weeks 2 or 3(RCs, MSCs), and at week 4(CCs) for the majority of metrics. There were significantly fewer catheter-tip movements using advanced catheter technology after training (Week 5: CC 74 IQR(59-89) versus MSC 62(44-81); p = 0.028, and RC 33 (28-44); p = 0.012). RCs virtually eliminated wall hits at the arch (CC 29(28-76) versus RC 8(6-9); p = 0.005) and produced significantly higher overall performance scores (p < 0.02). CONCLUSION: Advanced endovascular catheters, although more intricate, do not seem to take longer to master and in some areas offer clear advantages with regards to positional control, at a faster rate. RCs seem to be the most intuitive and advanced skill acquisition occurs with minimal training. Robotic endovascular technology may have a significantly shorter path to proficiency allowing an increased number of trainees to attempt more complex endovascular procedures earlier and with a greater degree of safety.

Identification of patient safety improvement targets in successful vascular and endovascular procedures: analysis of 251 hours of complex arterial surgery.

OBJECTIVES: To investigate failures in patient safety for patients undergoing vascular and endovascular procedures to guide future quality and safety interventions. DESIGN: Single centre prospective observational study. METHODS: 66 procedures (17 thoracoabdominal and 23 abdominal aortic aneurysms, 4 carotid and 22 limb procedures) were observed prospectively over a 9-month period (251 h operating time) by two trained observers. Event logs were recorded for each procedure. Two blinded experts identified and independently categorised failures into 22 types (using a validated category tool) and severity (5-point scale). Data are expressed as median (range). Statistical analysis was performed using Mann-Whitney U, Kruskal-Wallis and Spearman's Rank tests. RESULTS: 1145 failures were identified with good inter-assessor reliability (Cronbach's alpha 0.844). The commonest failure types related to equipment (including unavailability, configuration and other failures) (269/1145 [23.5%]) and communication (240/1145 [21.0%]). A comparatively lower number of technical and psychomotor failures were identified (103 [9.0%]). The number of failures correlated with procedure duration (rho = 0.695, p < 0.001) but not anatomical site of the procedure or pathology of the disease process. Failure rate was higher in patients undergoing combined surgical/endovascular procedures compared to open surgery (median 5.7/h [IQR 4.2-8.1] vs 3.0/h [2.5-3.5]; p < 0.001). The severity of failures was similar (1.5/5 [1-2] vs 1/5 [1-2] respectively; p = 0.095). For combined procedures, failure rates were significantly higher during the endovascular phase (9.6/h [7.5-13.7]) compared to the non-endovascular phase (3.0/h [1.0-5.0]; p < 0.001). CONCLUSIONS: Failures in patient safety are common during complex arterial procedures. Few failures were severe, although minor failures during critical stages and accumulation of multiple minor failures may potentially be important. Failures occurred especially during the endovascular phase and were often related to equipment or communication aspects. Interventions to improve procedural safety and quality of care should primarily target these specific areas.