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Objectives: The use of transcatheter aortic valve implantation (TAVI) is rapidly increasing with advances in technology and improved clinical outcomes. Adoption of robotic catheter technologies could have a role in TAVI, in different stages of the procedure, to improve endovascular tool manipulation and potentially reduce the risk of cerebral embolization. The aim was to determine whether there are advantages in using a robotic catheter for TAVI in the initial stages of the procedure; aortic arch navigation and valve crossing., Methods: A silicone in vitro model of the aorta and stenotic aortic valve was developed. Fifteen operators performed the fluoroscopy-guided simulation using manual and robotic techniques. Performance metrics-time and vessel wall contact (wall-hits) were compared (Wilcoxon's signed-rank test)., Results: Overall, the time taken for robotic arch navigation was increased (3.09 min interquartile range (1.24-6.29) vs 1.21 min (0.15-4.42); P = 0.03). Contact with the aortic arch wall, however, significantly decreased using the robotic catheter: wall-hits 1 (0-5) vs 6 (2-22), P < 0.01. For valve crossing, there was no significant increase in time and wall-hits when using the robotic technology., Conclusions: Use of robotic catheter technology is feasible in the initial stages of TAVI. Although it takes longer, robotic navigation reduces contact with the aortic arch wall, potentially reducing the embolic risk during endovascular manipulation. Using a robotic catheter is possible without increasing the number of wall-hits during valve crossing. This may provide a stable platform for wire positioning in the ventricle. With improvements in technology, perhaps allowing valve deployment, the stability and accuracy of the robotic arm may further improve performance.

Objective: Fenestrated stent grafting has become increasingly popular as a means to manage complex aortic pathology, including juxta- and pararenal aneurysms. The design of a recently developed custom-made fenestrated stent graft, in theory, confers advantages when managing anatomically challenging aortic morphology. This study evaluated its feasibility in anatomically challenging scenarios., Methods: Over a 12-month period, 20 patients received fenestrated stent grafts. Among those, 13 patients with juxtarenal or type IV thoracoabdominal aortic aneurysms underwent endovascular repair with the novel fenestrated stent graft at a single UK institution. Data on aneurysm morphology and immediate and short-term results were collected prospectively., Results: The mean aneurysmal sac size was 7.3 cm (range, 5.5-10.0 cm). The mean infrarenal neck length was 4.4 mm (range, 0-9 mm), and in three cases was lined by a pre-existing infrarenal stent graft. Nine cases had an infrarenal neck angulation of 60(°) or more in either the anteroposterior or coronal planes. Five cases had ≥50% thrombus at the proximal landing zone. A total of 35 target vessels were cannulated, of which six right renal and four left renal arteries were angulated ≥120(°). Two-thirds of cannulated celiac trunks were angulated ≥120(°), and one cannulated superior mesenteric artery was angulated ≥ 140(°). Seven of the cannulated targets were stenosed more than 60%. One patient had two right renal arteries arising 3 mm from each other. Four right and four left common iliac arteries were angulated ≥90(°) in relation to the infrarenal aorta. Technical success was 100%. Median time from date of procedure to most recent follow-up with computed tomography scanning was 33 weeks. There was no type I or III endoleak. One type II endoleak was observed at the time of most recent computed tomography scanning and treated expectantly. There was a single incident of left renal artery occlusion. One patient required repair of a brachial artery, fasciotomies, and temporary haemofiltration. One patient died from ischemic heart disease 77 weeks after the procedure., Conclusions: The use of the novel fenestrated stent graft system in patients with hostile aortic aneurysmal morphology is feasible with acceptable short-term outcomes., (Copyright © 2014 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

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.

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., (Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Non-typhoidal Salmonella infections typically cause self-limiting gastroenteritis. However, extraintestinal focal infections, including mycotic aneurysms of the aorta, can also occur. We present the case of a 71-year-old man with chronic lymphocytic leukemia (CLL) and a large type V thoracoabdominal mycotic aneurysm infected with Salmonella enteritidis, complicated by thoracolumbar spondylodiscitis, paravertebral collections, and epidural abscess. This is the first report of Salmonella aortitis in the setting of CLL, and the unusual extent of local infective invasion seen here with Salmonella enteritidis infection raises a suspicion of CLL-related immunosuppression as a direct predisposing factor. This case illustrates the need to consider the possibility of an immune defect, even in CLL patients with normal leukocyte counts. The underlying mechanisms are unclear, but are likely to involve defects in cell-mediated immunity, thought to be of particular importance in invasive infections with intracellular pathogens such as Salmonella spp., (Copyright © 2013 Elsevier Inc. All rights reserved.)

Background: Surgical technology has led to significant improvements in patient outcomes. However, failures in equipment and technology are implicated in surgical errors and adverse events. We aim to determine the proportion and characteristics of equipment-related error in the operating room (OR) to further improve quality of care., Methods: A systematic review of the published literature yielded 19 362 search results relating to errors and adverse events occurring in the OR, from which 124 quantitative error studies were selected for full-text review and 28 were finally selected., Results: Median total errors per procedure in independently-observed prospective studies were 15.5, interquartile range (IQR) 2.0-17.8. Failures of equipment/technology accounted for a median 23.5% (IQR 15.0%-34.1%) of total error. The median number of equipment problems per procedure was 0.9 (IQR 0.3-3.6). From eight studies, subdivision of equipment failures was possible into: equipment availability (37.3%), configuration and settings (43.4%) and direct malfunctioning (33.5%). Observed error rates varied widely with study design and with type of operation: those with a greater burden of technology/equipment tended to show higher equipment-related error rates. Checklists (or similar interventions) reduced equipment error by mean 48.6% (and 60.7% in three studies using specific equipment checklists)., Conclusions: Equipment-related failures form a substantial proportion of all error occurring in the OR. Those procedures that rely more heavily on technology may bear a higher proportion of equipment-related error. There is clear benefit in the use of preoperative checklist-based systems. We propose the adoption of an equipment check, which may be incorporated into the current WHO checklist.

Purpose: To investigate the quality of stent-graft fenestrations created in vitro using different needle puncture and balloon dilation angles in different commercial endografts., Methods: Fenestrations were made in a standardized fashion in 3 different endograft types: Talent monofilament twill woven polyester, Zenith multifilament tubular woven polyester, and Endofit thin-walled expanded polytetrafluoroethylene (PTFE). Punctures were made at 30°, 60°, and 90° angles using a 20-G needle and dilated using 6-mm standard and 7-mm cutting balloons; at least 6 fenestrations were made at each angle with standard balloons and at least 6 with cutting balloons. The 137 fenestrations were examined under light microscopy; quantitative and qualitative digital image analysis was performed to determine size, shape, and fenestration quality., Results: PTFE grafts were easier to puncture/dilate, resulting in larger, elliptical fenestrations with overall better quality than the Dacron grafts; however, the puncture/dilation angle made an impact on the shape and quality of fenestrations. A significant number of fabric tears were observed in PTFE fabric at <90° puncture/dilation angles compared to Dacron grafts. In Dacron grafts, fenestration quality was significantly higher with 90° puncture/dilation angles (higher in Talent grafts). Cutting balloon use resulted in significantly more fabric tears and poor quality fenestrations in all graft types., Conclusion: Different endografts behave significantly differently when fenestrations are fashioned. Optimum puncture/dilation is important when considering in vivo fenestration techniques. Improvements in instrumentation, materials, and techniques are required to make this a reliable and reproducible endovascular option.

Objective: To asses whether Angiotensin-converting enzyme inhibitors (ACEIs) and angiotensin receptor blockers (ARBs) are underused in patients with aortic disease due to concerns regarding flow limiting (>70%) renal artery stenosis (RAS)., Design: A prospective analysis of patients admitted for aortic surgery was performed (January-July 2009). Co-morbidity, ACEI/ARB use and renal function were recorded. Computerised tomography (CT) angiograms were reviewed by a single blinded radiologist for the presence and severity of RAS., Setting: St Mary's Hospital, Vascular Unit, Imperial College Healthcare NHS Trust, London, UK., Participants: 75 randomly selected patients admitted to our vascular unit including elective and emergency admissions., Main Outcome Measures: Indications for ACEI therapy were identified as determined by the National Institute of Health and Clinical Excellence (NICE) guidance. The ratio of the measurement distal to the stenosis and at the area of maximal stenosis on CT angiography were used to calculate the percentage RAS., Results: 60 patients were identified (15 patients excluded due to previously modified renal vessels). The median age was 73 [interquartile range 68, 77]. Their underlying aortic disease included 52 (87%) aortic aneurysm, 6 (10%) with aortic dissection, 1 (1.7%) patient with occlusive disease and 1 (1.7%) patient with mycotic disease. Overall, 56/60 (93%) patients had at least one indication for ACEI therapy. 33/60 (55%) of patients were already receiving ACEI. CT angiogram examination demonstrated 17/60 (28%) patients have RAS of some degree, of which only 9/60 (15%) have flow limiting RAS., Conclusion: A large proportion of aortic patients do not receive ACEI/ARB therapy despite definite indications and a low prevalence of flow-limiting RAS is low. After the exclusion of RAS at angiography, careful introduction of ACEI therapy with appropriate monitoring could be considered for many more patients.

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., (Copyright © 2013 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

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., (Copyright © 2012 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

This report describes a patient with pseudoxanthoma elasticum (PXE) who presented with an incidental finding of a renal artery aneurysm. PXE is a rare genetic condition. It is associated with calcification of elastin fibers and is characterized by skin, eye, and cardiovascular complications. Our patient was previously treated for retinal and gastrointestinal hemorrhage and coronary artery disease, and is under surveillance for cerebral aneurysms. Five reports in the published literature have described aneurysms in patients with PXE, but, to our knowledge, this is the first report of a patient with PXE and renal artery aneurysm. The literature on PXE and aneurysms is reviewed., (Copyright © 2013 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

A 67-year-old man underwent robot-assisted three-vessel fenestrated endovascular aneurysm repair (FEVAR) for a 7.3-cm juxtarenal aneurysm. The 6-F robotic catheter was manipulated from a remote workstation, away from the radiation source. Robotic cannulation of the left renal artery was achieved within 3 minutes. System setup time was 5 minutes. There were no postoperative complications. Computed tomography angiography performed at discharge and at 4-month follow-up confirmed target vessel patency with no evidence of an endoleak. Selective cannulation of target vessels during FEVAR using this novel technology is feasible. Endovascular robotics may have a role in simplifying complex endovascular tasks and potentially reducing radiation exposure to the operator., (Copyright © 2013 SIR. Published by Elsevier Inc. All rights reserved.)

Background: Unintentional renal artery occlusion after endovascular aortic aneurysm repair (EVAR) is an uncommon phenomenon. The sequelae from this specific complication are severe; consequently, the topic of renal artery coverage is a pertinent issue. We present a case series of patients undergoing EVAR with unintentional renal artery coverage, review the treatment options available, and suggest a treatment algorithm for this scenario based on the evidence., Methods and Results: We report four patients who were found to have renal artery occlusion after EVAR detected up to 5 weeks postoperatively. Renal revascularization was achieved using endovascular renal artery stenting in two patients, and open hepato-spleno-renal bypass in the remaining two cases. Treatment strategies used led to symptom resolution and recovery of renal function in all cases., Conclusions: Both open and endovascular techniques may be used as procedures to treat this condition-the choice of procedure is primarily determined by accessibility of the renal orifice., (Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.)

Purpose: To determine the type and frequency of errors during vascular interventional radiology (VIR) and design and implement an intervention to reduce error and improve efficiency in this setting., Materials and Methods: Ethical guidance was sought from the Research Services Department at Imperial College London. Informed consent was not obtained. Field notes were recorded during 55 VIR procedures by a single observer. Two blinded assessors identified failures from field notes and categorized them into one or more errors by using a 22-part classification system. The potential to cause harm, disruption to procedural flow, and preventability of each failure was determined. A preprocedural team rehearsal (PPTR) was then designed and implemented to target frequent preventable potential failures. Thirty-three procedures were observed subsequently to determine the efficacy of the PPTR. Nonparametric statistical analysis was used to determine the effect of intervention on potential failure rates, potential to cause harm and procedural flow disruption scores (Mann-Whitney U test), and number of preventable failures (Fisher exact test)., Results: Before intervention, 1197 potential failures were recorded, of which 54.6% were preventable. A total of 2040 errors were deemed to have occurred to produce these failures. Planning error (19.7%), staff absence (16.2%), equipment unavailability (12.2%), communication error (11.2%), and lack of safety consciousness (6.1%) were the most frequent errors, accounting for 65.4% of the total. After intervention, 352 potential failures were recorded. Classification resulted in 477 errors. Preventable failures decreased from 54.6% to 27.3% (P < .001) with implementation of PPTR. Potential failure rates per hour decreased from 18.8 to 9.2 (P < .001), with no increase in potential to cause harm or procedural flow disruption per failure., Conclusion: Failures during VIR procedures are largely because of ineffective planning, communication error, and equipment difficulties, rather than a result of technical or patient-related issues. Many of these potential failures are preventable. A PPTR is an effective means of targeting frequent preventable failures, reducing procedural delays and improving patient safety.

Purpose: To assess the incidence of errors before and after implementation of a structured mental rehearsal prior to the endovascular phase of combined open/endovascular arterial procedures., Methods: Over 6 weeks, 15 combined open/endovascular procedures (7 abdominal aorta and 8 thoracic aorta) lasting 58 hours were evaluated by a trained observer. In a blinded fashion, 2 individuals scrutinized event logs for errors, which were categorized by type, by potential to cause patient harm (danger), and by potential to disrupt the procedure (delay). After 9 procedures, a focus group-devised structured mental rehearsal was implemented prior to the endovascular phase for 6 combined procedures. Error patterns were compared before and after implementation. Data are expressed as median (range)., Results: The error rate during the endovascular phase of the combined procedures was higher than the non-endovascular phase [7.64/hour (1.71-9.6) vs. 3.75/hour (1.71-5.54), respectively; p = 0.05]. Error rates during the endovascular phase were lower after the intervention compared to before [2.5/hour (1.4-6.0) vs. 7.6/hour (1.7-9.6), respectively; p = 0.05]. During the endovascular phase, danger and delay scores were also lower after the intervention [1.2/error (1.0-2.0) and 1.3/error (1.0-2.3), respectively] compared to before [1.75/error (1.4-2.5) and 2.0/error (1.3-2.5), respectively] (p = 0.036 and p = 0.036 for danger and delay, respectively)., Conclusion: A structured mental rehearsal before critical stages of procedures may reduce the rate and severity of intraoperative error.

Background: The aim of this paper is to review the potential role of endovascular interventions for young patients with lower-limb ischaemia., Methods: A literature search was performed of PubMed and Medline databases using appropriate search terms and limits. Case reports, retrospective studies, and prospective studies evaluating treatment of lower-limb ischemia in patients aged <50 years were scrutinized. Articles published between 1966 and 2010 were included in this review., Results: Premature atherosclerosis is likely to represent the commonest cause of lower-limb ischemia in patients aged <50 years, although the incidence of nonatherosclerotic causes such as popliteal entrapment syndrome, cystic adventitial disease, and arteritis in these patients is greater than in older patients. As with older patients, endovascular interventions may be beneficial for patients with symptoms secondary to atherosclerosis. At present, the perceived durability of open surgery may be more preferable to patients aged <50 years, but the development of new endovascular technology is challenging this view. Endovascular interventions such as catheter-directed thrombolysis have specific roles in the treatment of lower-limb ischemia due to nonatherosclerotic causes., Conclusion: The use of angioplasty and stenting procedures to treat young patients with lower-limb ischemia is increasing and has specific roles. However, many developmental causes and nonatherosclerotic conditions still require primary surgical correction., (Copyright © 2012 Annals of Vascular Surgery Inc. Published by Elsevier Inc. All rights reserved.)

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(®)., (Crown Copyright © 2010. Published by Elsevier Ltd. All rights reserved.)

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., (Crown Copyright © 2011. Published by Elsevier Ltd. All rights reserved.)

Objective: Conventional catheter instability and embolization risk limits the adoption of endovascular therapy in patients with challenging arch anatomy. This study investigated whether arch vessel cannulation can be enhanced by a remotely steerable robotic catheter system., Methods: Seventeen clinicians with varying endovascular experience cannulated all arch vessels within two computed tomography-reconstructed pulsatile flow phantoms (bovine type I and type III aortic arches), under fluoroscopic guidance, using conventional and robotic techniques. Quantitative (catheterization times, catheter tip movements, vessel wall hits, catheter deflection) and qualitative metrics (Imperial College Complex Endovascular Cannulation Scoring Tool [IC3ST]) performance scores were compared., Results: Robotic catheterization techniques resulted in a significant reduction in median carotid artery cannulation times and the median number of catheter tip movements for all vessels. Vessel wall contact with the aortic arch wall was reduced to a median of zero with robotic catheters. During stiff guidewire exchanges, robotic catheters maintained stability with zero deflection, independent of the distance the catheter was introduced into the carotid vessels. Overall IC3ST performance scores (interquartile range) were significantly improved using the robotic system: Type I arch score was 26/35 (20-30.8) vs 33/35 (31-34; P = .001), and type III arch score was 20.5/35 (16.5-28.5) vs 26.5/35 (23.5-28.8; P = .001). Low- and medium-volume interventionalists demonstrated an improvement in performance with robotic cannulation techniques. The high-volume intervention group did not show statistically significant improvement, but cannulation times, movements, and vessel wall hits were significantly reduced., Conclusion: Robotic technology has the potential to reduce the time, risk of embolization and catheter dislodgement, radiation exposure, and the manual skill required for carotid and arch vessel cannulation, while improving overall performance scores., (Copyright © 2011 Society for Vascular Surgery. Published by Mosby, Inc. All rights reserved.)

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., (Copyright © 2011. Published by Elsevier Ltd.)

This report describes endovascular stenting of an acute mycotic ascending aortic aneurysm. An eighty-three year old lady presented nine weeks after aortic valve surgery and subsequent thyroidectomy with sternal pain secondary to a mycotic ascending aortic pseudoaneurysm. The pseudoaneurysm was visible through the unhealed sternum. Open repair was considered too high a mortality risk. Endovascular stenting was performed using two covered infrarenal proximal extension devices (GORE Excluder Aortic Extender(®), W. L. Gore & Associates, Flagstaff, Arizona, USA) deployed from a right axillary approach utilising overdrive cardiac pacing. Post procedure imaging revealed shrinkage of the pseudoaneurysm sac., (Copyright © 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

Background: Emerging robotic technologies are increasingly being used by surgical disciplines to facilitate and improve performance of minimally invasive surgery. Robot-assisted intervention has recently been introduced into the field of vascular surgery to potentially enhance laparoscopic vascular and endovascular capabilities. The objective of this study was to review the current status of clinical robotic applications in vascular surgery., Methods: A systematic literature search was performed in order to identify all published clinical studies related to robotic implementation in vascular intervention. Web-based search engines were searched using the keywords "surgical robotics," "robotic surgery," "robotics," "computer assisted surgery," and "vascular surgery" or "endovascular" for articles published between January 1990 and November 2009. An evaluation and critical overview of these studies is reported. In addition, an analysis and discussion of supporting evidence for robotic computer-enhanced telemanipulation systems in relation to their applications in laparoscopic vascular and endovascular surgery was undertaken., Results: Seventeen articles reporting on clinical applications of robotics in laparoscopic vascular and endovascular surgery were detected. They were either case reports or retrospective patient series and prospective studies reporting laparoscopic vascular and endovascular treatments for patients using robotic technology. Minimal comparative clinical evidence to evaluate the advantages of robot-assisted vascular procedures was identified. Robot-assisted laparoscopic aortic procedures have been reported by several studies with satisfactory results. Furthermore, the use of robotic technology as a sole modality for abdominal aortic aneurysm repair and expansion of its applications to splenic and renal artery aneurysm reconstruction have been described. Robotically steerable endovascular catheter systems have potential advantages over conventional catheterization systems. Promising results from applications in cardiac interventions and preclinical studies have urged their use in vascular surgery. Although successful applications in endovascular repair of abdominal aortic aneurysm and lower extremity arterial disease have been reported, published clinical experience with the endovascular robot is limited., Conclusions: Robotic technology may enhance vascular surgical techniques given preclinical evidence and early clinical reports. Further clinical studies are required to quantify its advantages over conventional treatments and define its role in vascular and endovascular surgery., (Crown Copyright © 2011. Published by Mosby, Inc. All rights reserved.)

Objective: To evaluate the outcome of hybrid treatment of the aortic arch with supra-aortic debranching and endovascular stent-graft repair in a selected group of patients with complex disease., Design: Case series study with retrospective analysis of prospectively collected non-randomised data., Methods: Patients with hybrid repair of complex arch disease at a single centre over a 6-year period were enrolled in the study. Only patients with extensive arch pathologies requiring debranching of at least the left carotid artery were considered. Patients were divided into those who underwent complete and partial supra-aortic revascularisation. The χ2 test was used to evaluate differences in outcomes. Logistic regression analyses were applied to identify predictors of poor outcome., Results: A total of 33 patients were included in the study. Complete and partial arch repair was performed in nine and 24 patients, respectively. The aortic disease extended to the thoracic and abdominal aorta in 39% and 52% of the patients, respectively. One-third of the patients (30%) were treated on an urgent/emergency basis. Elective 30-day mortality and morbidity rates were 13% and 35%, respectively. Early mortality was significantly higher in the complete arch repair group (p=0.046). Pre-existing renal impairment was identified as a poor prognostic factor. All extra-anatomic bypasses remained patent and no aortic disease-related deaths occurred during a mean follow-up period of 23 months (range, 1.5-58 months). Complete arch repair was associated with an increased incidence of late endoleak (p=0.018)., Conclusions: Hybrid treatment of the aortic arch provides a feasible alternative treatment in patients who are high risk for conventional open surgical repair. Careful selection of patients is required to achieve satisfactory results., (Copyright © 2010 European Society for Vascular Surgery. Published by Elsevier Ltd. All rights reserved.)

The past 4 decades have witnessed tremendous strides in the evolution of endovascular technology with increased operator experience, greater availability of more sophisticated and versatile endovascular devices, and advances in imaging modalities. In an attempt to limit the physiologic derangements associated with aortic crossclamping and extensive tissue dissection during traditional open surgical repair of extensive thoracoabdominal aortic aneurysms, less invasive strategies have been explored using endovascular technology: hybrid approaches and solely endovascular techniques. This article describes these techniques and their advantages, their current role in thoracoabdominal aortic aneurysm repair and potential future developments in this field., (Copyright © 2010 The American Association for Thoracic Surgery. Published by Mosby, Inc. All rights reserved.)

Aims: To establish a method to assess amputation incidence that addresses the problems matching a numerator with an appropriate denominator in London and to demonstrate low amputation incidence associated with the activity of our multidisciplinary diabetic foot clinic., Methods: Hospital-coded inpatient data was examined to derive the numerator: the number of non-traumatic amputations performed on subjects with diabetes each financial year where the Primary Care Trust commissioner code was our main local Primary Care Trust. Denominators were derived from the main local Primary Care Trust's Quality and Outcomes Framework data sets. Not all Primary Care Trust subjects with diabetes receive inpatient care at our hospital, so that the denominators were corrected for the hospital's percentage market share for the provision of inpatient diabetes care for the Primary Care Trust each financial year, derived from the Dr Foster database., Results: Between April 2004 and April 2009, 44 Primary Care Trust subjects with diabetes underwent 34 minor and 10 major amputations at the hospital. Although the Primary Care Trust populations with and without diabetes increased, the hospital's Primary Care Trust percentage market share decreased, so that overall denominators decreased. The mean annual incidence of minor, major and total amputations over the five financial years was 14.7, 4.2 and 18.9 per 10 000 subjects with diabetes,respectively, and 3.9, 1.1 and 5.0 per 100 000 of the general population, respectively., Conclusions: We report for the first time amputation incidence in a London population. Acknowledging the limitations of accurately defining incidence in London, we demonstrate low amputation incidence associated with our multidisciplinary diabetic foot clinic.

Aortic dissection is the most common acute catastrophic event affecting the thoracic aorta. The majority of patients presenting with an uncomplicated type B dissection are treated medically, but 25% of these patients develop subsequent aneurysmal dilatation of the thoracic aorta. This study aimed at gaining more detailed knowledge of the flow phenomena associated with this condition. Morphological features and flow patterns in a dissected aortic segment of a presurgery type B dissection patient were analyzed based on computed tomography images acquired from the patient. Computational simulations of blood flow in the patient-specific model were performed by employing a correlation-based transitional version of Menter's hybrid k-epsilon/k-omega shear stress transport turbulence model implemented in ANSYS CFX 11. Our results show that the dissected aorta is dominated by locally highly disturbed, and possibly turbulent, flow with strong recirculation. A significant proportion (about 80%) of the aortic flow enters the false lumen, which may further increase the dilatation of the aorta. High values of wall shear stress have been found around the tear on the true lumen wall, perhaps increasing the likelihood of expanding the tear. Turbulence intensity in the tear region reaches a maximum of 70% at midsystolic deceleration phase. Incorporating the non-Newtonian behavior of blood into the same transitional flow model has yielded a slightly lower peak wall shear stress and higher maximum turbulence intensity without causing discernible changes to the distribution patterns. Comparisons between the laminar and turbulent flow simulations show a qualitatively similar distribution of wall shear stress but a significantly higher magnitude with the transitional turbulence model.

Objective: Fenestrated stent grafting has allowed the treatment of complex thoraco-abdominal aneurysm disease via a totally endovascular approach, but the procedure can be technically challenging and time consuming. We investigated whether this procedure may be enhanced by remotely steerable robotic endovascular catheters., Methods: A four-vessel fenestrated stent graft partially deployed within a computed tomography (CT)-reconstructed pulsatile thoraco-abdominal aneurysm silicon model was used. Fifteen operators were recruited to participate in the study and divided into three groups, based on their endovascular experience: group A (n = 4, 100-200 endovascular procedures, group B (n = 5, 200-300), and group C (n = 6, >300). All operators were asked to cannulate the renal and visceral vessels under fluoroscopic guidance, using conventional and robotic techniques. Quantitative (catheterization times and wire/catheter tip movements) and qualitative metrics (procedure-specific-rating scale [IC3ST]), which grades operators on catheter use, instrumentation, successful cannulation/catheterization, and overall performance were compared., Results: Median procedure time for cannulation of all four vessels was reduced using the robotic system (2.87 min, interquartile range [IQR; 2.20-3.90] versus 17.24 min [11.90-19.80]; P < .001) for each individual operator, regardless of the level of endovascular experience. The total number of wire/catheter movements taken to complete the task was also significantly reduced (38, IQR [29-57] versus 454 [283-687]; P < .001). There were significant differences in time and movement for cannulation of each individual vessel in the phantom. Robotic catheter operator radiation exposure was negligible as the robotic workstation is remote and away from the radiation source. Overall performance scores significantly improved using the robotic system, despite minimal operator exposure to this technology (IC3ST score 29/35, IQR [22.8-30.7] versus 19/35 [13-24.3]; P = .002). Each group of operators demonstrated an improvement in performance with robotic cannulation. For group A, median IC3ST score was 28/35, IQR (22-33) versus 15/35 (11-20); P = .04; for group B, 30/35 (27-31) versus 19/35 (18-24); P = .07; and for group C, 28.8/35 (28.5-29) versus 22/35 (16-24); P = .06. For groups B and C, these differences did not reach statistical significance., Conclusion: Robotic catheterization of target vessels during this procedure is feasible and minimizes radiation exposure for the operator. Steerable robotic catheters with intuitive control may overcome some of the limitations of standard catheter technology, enhance target vessel cannulation, reduce instrumentation, and improve overall performance scores.

Paraplegia affects up to 22% of patients undergoing thoarcoabdominal aneurysm surgery, producing long-term morbidity and a significant burden to healthcare. This article discusses the mechanisms that may lead to paraplegia during open and endovascular repair from an anatomical and physiological perspective. There are many adjuncts that must be considered to reduce the risk of spinal cord injury, such as revascularisation of intercostal arteries, maintenance of high mean blood pressure, spinal cord drainage and cooling. These adjuncts are discussed, highlighting the evidence available for each method and the practical ways in which they may be used.

Objectives: To describe our experience of treating juxtarenal (JRAAA's <4mm neck) and thoracoabdominal aortic aneurysms (TAAA's) using fenestrated and branched stent graft technology., Design: Prospective single centre experience., Methods: Since 2005, 29 fenestrated/branched procedures have been performed. 15 patients are studied with JRAAAs (n=7; median neck length 0mm (IQR 0-3.8)) or TAAAs (type I (n=2), III (n=2), IV (n=4)). ASA grade III in 12/15. Maximum diameter of aneurysm 64 mm (56-74 mm). Aneurysms were excluded using covered stents or branches from the main body to patent visceral vessels (40 target vessels total). Pre-operative and follow-up CT scans (1, 3, and 12 months) were analysed by a single Vascular Interventional Radiologist., Results: Technical success for cannulation and stenting of target vessels was 98%. In-hospital mortality was 0%. One patient underwent conversion to open repair. Five had major complications including one paraplegia (type III TAAA) with subsequent recovery. Median length of stay was 9 days (IQR 7-18.75). At a median follow-up of 12 months (9-14), CT confirmed 36/37 (97%) target vessels remain patent. Sac size increased >5 mm in one patient only. There were no type I endoleaks, three type II endoleaks (one embolised, two under surveillance) and three type III endoleaks (two successfully treated percutaneously, one aneurysm ruptured 18 months after endografting and died)., Conclusion: In selected patients, fenestrated and branched stents appear to be a safe and effective alternative to surgery for juxtarenal and thoracoabdominal aneurysms. The complication and mortality rates are low. The long-term durability of this procedure, however, needs to be proven.

Background: Patients undergoing carotid endoluminal intervention are at risk of embolic stroke even with the use of distal protection devices. Matrix metalloproteinases (MMPs) have been implicated as a causal factor in plaque instability leading to spontaneous embolisation. We investigated whether plasma MMP levels correlated with the embolisation during carotid endoluminal intervention., Methods: Thirty circumferentially intact carotid endarterectomy specimens were subjected to a standardised angioplasty procedure in a pulsatile ex vivo model. Emboli collected in a series of distal filters were counted and sized. Plasma samples were collected pre-operatively and analysed for MMP-7 and MMP-8 levels using Western immunoblotting. MMP-1 and MMP-13 levels were determined using ELISA. Emboli number and maximum size were correlated with plasma levels of the MMPs using Spearmans rank., Results: Total MMP-8 levels were related to maximum embolus size (r=0.442, p=0.005) but not emboli number (r=0.342, p=0.052). MMP-1, -7 and -13 were not correlated with either emboli number or with maximum embolus size., Conclusion: Pre-operative plasma MMP-8 levels are related to the size of emboli from plaques during carotid endovascular intervention. Further in vivo studies need to be performed to assess the importance of this finding. There is potential for development of plasma markers to identify those patients at greater risk of embolic stroke during carotid endoluminal intervention.

Purpose: To investigate if relationships exist among macrophage infiltration, plasma matrix metalloproteinase (MMP) levels, and the number of emboli generated during endoluminal carotid interventions., Methods: Carotid endarterectomy specimens excised as intact cylinders (n=27) were subjected to a standardized angioplasty procedure under radiological guidance in an ex vivo pulsatile flow model. Emboli collected in distal filters were counted and sized using microscopy. Preoperative plasma gelatinase activity was determined by gelatin zymography and quantified using image analysis software. Levels of tissue inhibitors of metalloproteinases (TIMP) 1 and 2 were determined by ELISA. Macrophages within postangioplasty plaques were analyzed using immunohistochemical staining for CD68 antigen and graded by a blinded examiner. Statistical analysis was performed using Spearman's rank correlation., Results: The median number of emboli recorded during angioplasty was 104 (interquartile range 33.75-242.5, absolute range 13-1090). Plasma MMP-9 and MMP-2 levels correlated with emboli number (r=0.544 [p=0.003] and r=0.412, [p=0.033], respectively), while TIMP-1 and TIMP-2 levels did not. Macrophage infiltration within the plaques correlated with emboli number (r=0.722, p<0.001) and the plasma MMP-9 level (r=0.489, p=0.010)., Conclusions: These data indicate that plaque macrophage infiltration may play a role in the generation of emboli during endoluminal carotid intervention, possibly via modulation of protease activity.

Inappropriate alterations in flow in the form of steal syndromes are a well recognised phenomenon. In the subclavian steal syndrome a proximal subclavian artery stenosis is responsible for reversal of flow in the vertebral artery and symptoms of vertebrobasilar ischaemia occur with arm movement. After internal mammary artery grafting to the coronary circulation, during coronary artery bypass surgery (CABG), coronary subclavian steal can occur. Retrograde flow occurs from the myocardium through the internal mammary graft to the subclavian artery secondary to a proximal subclavian stenosis. It is a rare but important cause of recurrent chest pain after coronary surgery.

High-resolution magnetic resonance imaging was combined with computational modeling to create focused three-dimensional reconstructions of the distal anastomotic region of autologous vein peripheral bypass grafts in a preliminary series of patients. Readily viewed on a personal computer or printed as hard copies, a detailed appreciation of in vivo postoperative features of the anastomosis is possible. These reconstructions are suitable for analysis of geometric features, including vessel caliber, tortuosity, anastomotic angles, and planarity. Some potential clinical and research applications of this technique are discussed.

Background: Elective juxtarenal abdominal aneurysm repair has a significantly lower mortality rate than suprarenal repair. Identification of factors affecting outcome may lead to a reduction in mortality rate for suprarenal repair., Methods: Data were collected prospectively between 1993 and 2000 for 130 patients who underwent type IV thoracoabdominal aneurysm (TAA) repair and 44 patients who had juxtarenal aneurysm (JRA) repair. Preoperative risk factors and operative details were compared between groups and related to outcome after TAA repair (there were only two deaths in the JRA group)., Results: The in-hospital mortality rate was significantly higher following TAA repair (20.0 per cent; 26 of 130 patients) than JRA repair (4.5 per cent; two of 44). Raised serum creatinine concentration was the only preoperative factor (P = 0.013) and visceral ischaemia the only significant operative factor (P = 0.001) that affected mortality after TAA repair., Conclusion: JRA repair was performed with similar risks to those of infrarenal aneurysm repair. Impaired preoperative renal function was related to death following TAA repair and conservative treatment should be considered for patients with a serum creatinine level above 180 micromol/l. Reducing the duration of visceral ischaemia might improve outcome., (Copyright 2003 British Journal of Surgery Society Ltd. Published by John Wiley & Sons, Ltd.)

Objectives: Carotid endoluminal intervention is an alternative to surgery but carries a risk of embolic stroke even with distal protection devices. We investigated the clinical features and degree of stenosis related to number and size of emboli during carotid angioplasty., Design: An experimental ex vivo study., Materials: An ex vivo pulsatile flow model was used in which temperature, velocity, flow, pressure and viscosity characteristics were designed to simulate the carotid circulation., Methods: Carotid endarterectomy specimens excised as intact cylinders (n = 28) were subjected to a standardised angioplasty procedure using radiological guidance. Emboli collected in filters placed distally were counted and sized using microscopy., Results: Median number of emboli during angioplasty was 133 (range 15-1331). Median size of the largest embolus was 700 microns (range 75-2400). Severity of stenosis correlated with increased maximum size (r = 0.55, p = 0.012). Statin therapy >4 weeks pre-operatively was associated with reduced emboli number and size (54 (range 15-748) vs 247 (range 37-1331) [p = 0.023] and 400 microm (range 75-2400) vs 1300 microm (range 600-2200) [p = 0.022])., Conclusions: In this model a wide range of emboli number and size were produced. Number and size of embolic particles were highest in patients with high-grade stenoses not receiving statin therapy.