Randomized Controlled Trial of Compression After Endovenous Thermal Ablation of Varicose Veins (COMETA Trial).

BACKGROUND: The 21st century has witnessed a rise in the use of endovenous thermal ablation. Being highly clinically and cost-effective and improving the quality of life of patients, they are now considered to be the "gold-standard" treatment for varicose veins. Post-intervention management, especially in terms of postoperative compression, however, remains unclear. As a result, a randomized study was undertaken to investigate the effects of wearing compression stockings after varicose vein treatment. METHOD: Patients with saphenous vein reflux undergoing treatment with endothermal ablation (with or without concurrent phlebectomies) were randomized to receive either 7 days of compression stockings or no stockings. The primary outcome measure for this study was the pain score over the first 10 postoperative days. The pain scores, clinical score, time to return to normal activities, and ecchymosis were assessed. Patients were followed-up at 2 weeks and 6 months post-ablation. RESULTS: In total, 206 patients were randomized, 49% of them to the compression group. The mean age was 49.7 (±16) years and approximately 51% of the population was male. The median pain score in the compression group using a visual analog scale was significantly lower on days 2-5, compared to the no compression group. Those having concurrent phlebectomies and compression stockings also had significantly better pain scores on days 1-3, day 5, and day 7. Improvement in the median venous clinical severity score was noted at 6-month follow-up, but this was not significant. No difference in the generic- or disease-specific quality of life was observed and the time to return to activities was similar. There were no differences in the degree of ecchymosis between the 2 groups and both groups had similar occlusion rates. CONCLUSIONS: These results indicate that wearing compression stockings after endothermal ablation is advantageous in the first few days after treatment and is especially beneficial for those having concurrent phlebectomies.

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.

Four-year results of the Bolton relay proximal scallop endograft in the management of thoracic and thoracoabdominal aortic pathology with unfavorable proximal landing zone.

BACKGROUND: Thoracic endovascular aortic repair with a scallop design (scallop-TEVAR) is a useful treatment strategy to extend the proximal landing zone (PLZ), while maintaining perfusion to one or more of the supra-aortic trunks (SATs) when treating aortic pathology with an unfavorable PLZ. The durability of this approach with the Bolton Relay scallop endograft (Terumo Aortic, Sunrise, Fla) has not been established. METHODS: A retrospective review of prospectively collected data on consecutive patients that received scallop-TEVAR in zones 0 to 2 at a tertiary aortic unit was undertaken. The main outcome was durability, characterized by survival estimates, freedom from reintervention to the thoracic aorta and PLZ, migration and aneurysm sac regression. RESULTS: Between 2009 and 2019, 38 patients (71% male; median age, 70 years) underwent scallop-TEVAR for thoracic aortic pathology (n = 28, 74%) or as a part of thoracoabdominal aneurysm repair (n = 10 [26%]). The use of scallop-TEVAR significantly extended the PLZ (median, 5 mm preoperative PLZ vs 26 mm extended PLZ; P = .0001). A total of 41 SATs were perfused with a scallop, including the left subclavian artery (n = 25), left common carotid artery (n = 6), neo/innominate artery (n = 4), left subclavian artery, and vertebral artery (n = 1), innominate artery, and left common carotid artery (n = 2) in conjunction with 15 extra-anatomical bypasses. The PLZ was at Ishimaru zone 0 and 1 in 6 cases (16%), respectively, and zone 2 in 26 cases (68%). Technical success was 98%. The 30-day mortality was 5% (2/38; 1 death from myocardial infarction and 1 from multiorgan failure). A minor stroke occurred in three patients (8%) and temporary spinal cord ischemia in two patients (5%). The median follow-up was 4.5 years (range, 0-10.53 years) during which two patients (5%) developed type Ia endoleak and required intervention to the PLZ (one from device-related migration and one from disease progression). All-cause and aorta-related survival were 72% and 85% and freedom from thoracic and PLZ reintervention was 92% and 97%, respectively. There were no cases of early or late thoracic aortic rupture, retrograde type A aortic dissection or SAT occlusion. CONCLUSIONS: Scallop-TEVAR offers a less invasive treatment option to extend the seal zone in selected patients with an unfavorable PLZ, allowing for a durable repair in terms of overall survival and reintervention. Periprocedural stroke remains a principle concern.

Wearable Activity Monitors in Home Based Exercise Therapy for Patients with Intermittent Claudication: A Systematic Review.

OBJECTIVE: Intermittent claudication (IC) can severely limit functional capacity and quality of life. Supervised exercise therapy is the recommended first line management; however, this is often limited by accessibility, compliance and cost. As such, there has been an increased interest in the use of wearable activity monitors (WAMs) in home based telemonitoring exercise programmes for claudicants. This review aims to evaluate the efficacy of WAM as a feedback and monitoring tool in home based exercise programmes for patients with IC. DATA SOURCES: A search strategy was devised. The databases MEDLINE, EMBASE, and Web of Science were searched through to April 2020. REVIEW METHODS: Randomised trials and prospective trials were included. Eligible trials had to incorporate WAMs as a feedback tool to target walking/exercise behaviour. The primary outcome was the change in walking ability. Study quality was assessed with risk of bias tool. RESULTS: A total of 1148 records were retrieved. Of these, eight randomised controlled trials and one prospective cohort study, all of which compared a WAM intervention against standard care and/or supervised exercise, met the inclusion criteria. Owing to heterogeneity between studies, no meta-analysis was conducted. WAM interventions improved measures of walking ability (heterogeneous outcomes such as maximum walking distance, claudication distance and six minute walk distance), increased daily walking activity (steps/day), cardiovascular metrics (maximum oxygen consumption), and quality of life. CONCLUSION: There is some evidence that home based WAM interventions are beneficial for improving walking ability and quality of life in patients with IC. However, existing studies are limited by inadequate sample size, duration, and appropriate power. Achieving consensus on outcome reporting and study methods, as well as maximising device adherence, is needed.

Short- and long-term outcomes in isolated penetrating aortic ulcer disease.

BACKGROUND: The optimum management of isolated penetrating aortic ulceration (PAU), with no associated intramural hematoma or aortic dissection is not clear. We evaluate the short- and long-term outcomes in isolated PAU to better inform management strategies. METHODS: We conducted a retrospective review of 43 consecutive patients (mean age, 72.2 years; 26 men) with isolated PAU (excluding intramural hematoma/aortic dissection) managed at a single tertiary vascular unit between November 2007 and April 2019. Twenty-one percent had PAU of the arch, 62% of the thoracic aorta, and 17% of the abdominal aorta. Conservative and surgical groups were analyzed separately. Primary outcomes included mortality, PAU progression, and interventional complications. RESULTS: Initially, 67% of patients (29/43) were managed conservatively; they had significantly smaller PAU neck widths (P = .04), PAU depths (P = .004), and lower rates of associated aneurysmal change (P = .004) compared with those initially requiring surgery. Four patients (4/29) initially managed conservatively eventually required surgical management at a mean time interval of 49.75 months (range, 9.03-104.33 months) primarily owing to aneurysmal degeneration. Initially, 33% of patients (14/43) underwent surgical management; 7 of the 14 procedures were urgent. Of the 18 patients, 17 eventually managed with surgical intervention had an endovascular repair; 2 of the 17 endovascular cases involved supra-aortic debranching, six used scalloped, fenestrated, or chimney stents. The overall long-term mortality was 30% (mean follow-up, 48 months; range, 0-136 months) with no significant difference between the conservatively and surgically managed groups (P = .98). No aortic-related deaths were documented during follow-up in those managed conservatively. There was no in-hospital mortality after surgical repair. Of these 18 patients, two required reintervention within 30 days for type I or III endoleaks. Among the 18 patients, seven died during follow-up (mean survival, 90.24 months; range, 66.48-113.88) with 1 of the 18 having a confirmed aortic-related death. CONCLUSIONS: Isolated, asymptomatic, small PAUs may be safely managed conservatively with regular surveillance. Those with high-risk features or aneurysmal progression require complex strategies for successful treatment with acceptable long-term survival.

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.

Wearable Sensor Technology Efficacy in Peripheral Vascular Disease (wSTEP): A Randomized Controlled Trial.

OBJECTIVE: To evaluate the effect of using wearable activity monitors (WAMs) in patients with intermittent claudication (IC) within a single-center randomized controlled trial. BACKGROUND: WAMs allow users to set daily activity targets and monitor their progress. They may offer an alternative treatment to supervised exercise programs (SEPs) for patients with IC. METHODS: Thirty-seven patients with IC were recruited and randomized into intervention or control group. The intervention consisted of a feedback-enabled, wrist-worn activity monitor (WAM) in addition to access to SEP. The control group was given access to SEP only. The outcome measures were maximum walking distance (MWD), claudication distance (CD), and quality of life as measured by the VascuQol questionnaire. Participants were assessed upon recruitment, and at 3, 6, and 12 months. RESULTS: Patients in the WAM group showed significant improvement in MWD at 3 and 6 months (80-112 m, to 178 m; P < 0.001), which was sustained at 12 months. The WAM group also increased CD (40 vs 110 m; P < 0.001) and VascuQol score (4.7 vs 5.8; P = 0.004). The control group saw a temporary increase in VascuQol score at 6 months (4.5 vs 4.7; P = 0.028), but no other improvements in MWD or CD were observed. Significantly higher improvements in MWD were seen in the WAM group compared with that in the control group at 6 months (82 vs -5 m; P = 0.009, r = 0.47) and 12 months (69 vs 7.5 m; P = 0.011, r = 0.52). CONCLUSIONS: The study demonstrates the significant, sustained benefit of WAM-led technologies for patients with IC. This potentially resource-sparing intervention is likely to provide a valuable adjunct or alternative to SEP.

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.

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.

Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair: A Benchmark for New Technologies.

PURPOSE: To evaluate the short- and long-term outcomes of hybrid repair of the arch and proximal descending aorta in a single tertiary center for aortic disease. METHODS: A retrospective analysis was performed of 55 patients (median age 67 years; 36 men) who underwent hybrid repair of thoracic aortic pathology with involvement of the arch between January 2005 and May 2015 at a single tertiary center. The pathologies included 40 (73%) with aneurysmal disease, 10 (18%) acute type B aortic dissections, 2 with acute aortic syndrome, an acute type A dissection, and left and aberrant right subclavian artery aneurysms. Seven (13%) procedures were performed as an emergency. Demographics and procedure characteristics were collected for analysis of survival and reinterventions. RESULTS: Complete aortic debranching was performed in 14 (25%) to facilitate endograft placement in zone 0; debranching was partial in 20 (36%) patients for zone 1 deployments and 21 (38%) for zone 2. Primary technical success was achieved in 51 (93%) cases. One patient died in-hospital from aneurysm rupture following aortic debranching prior to stent-graft repair. In another, the stent-graft procedure proved infeasible and was abandoned. The other 2 technical failures were due to type Ia endoleaks. Five (9%) patients died in-hospital (4 of 48 elective and 1 of 7 emergency cases); 2 of these patients died within 30 days (4%). Eight (14%) patients had a stroke, 6 of 48 elective and 2 of the 7 emergency patients. Spinal cord ischemia was reported in 3 (6%) patients. Mean follow-up was 74.6 months. Overall cumulative survival was 70% at 1 year, 68% at 2 years, and 57% at 5 years. Reintervention to the proximal landing zone for type Ia endoleak was required in 6% of cases. The overall rate of aortic reintervention was 18% at 1 year, 21% at 2 years, and 36% at 5 years. Overall extra-anatomic graft patency was 99%. CONCLUSION: Hybrid repair of the aortic arch and proximal descending thoracic aorta is technically feasible, with acceptable short-term mortality. There is a low rate of proximal landing zone reintervention when hybrid techniques are used to create an adequate proximal landing zone. Extra-anatomic bypass grafts have good long-term patency. Ongoing disease progression means that further distal aortic interventions are often necessary in patients with extensive disease.

Experience with a novel custom-made fenestrated stent graft in the repair of juxtarenal and type IV thoracoabdominal aneurysms.

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.

Robot-assisted uterine artery embolization: a first-in-woman safety evaluation of the Magellan System.

PURPOSE: To provide a technical description of robot-assisted uterine artery embolization and to investigate the safety and feasibility of the Magellan (Hansen Medical, Mountain View, California, USA) robotic catheter in this complex arterial bed. MATERIALS AND METHODS: Five women (mean age, 48.8 y) underwent robot-assisted bilateral uterine artery embolization over a 10-month period using the Magellan robotic catheter. Demographic, clinicopathologic, and endovascular performance metric data (fluoroscopy and cannulation times) were recorded as well as short-term outcomes. RESULTS: Robotic cannulation of bilateral internal iliac and uterine arteries was successful in all cases. Median right and left internal iliac artery cannulation and total fluoroscopy times were 3 minutes (interquartile range [IQR], 1.5-4 min), 2 minutes (IQR, 1.5-4 min), and 11 minutes (IQR, 9.5-14 min). Median right and left uterine artery cannulation times were both 11 minutes (IQR, 6.5-15 min and 8-12 min, respectively). Technical success was 100%. All patients were discharged on postoperative day 1, and there were no major or access site complications. At 6 months after the procedure, all patients reported significant improvement of symptoms, with a median increase in health-related quality-of-life score of 58% (48.5%-61.75%). CONCLUSIONS: The use of the new-generation Magellan system in uterine artery embolization is feasible and appears to be safe. The additional navigational capability and added maneuverability of the NorthStar catheter (Hansen Medical, Mountain View, California) may facilitate selective catheterization of small iliac artery divisions and may be useful in any procedure where complex arterial selection is needed.

Segmental arterial mediolysis: a systematic review of 85 cases.

BACKGROUND: Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy of unknown etiology with life-threatening manifestations. With advances in endovascular techniques, SAM is increasingly being managed without the need for major surgery. METHODS: A systematic review of the literature published on SAM between 1976 and 2012 was performed, focusing on arterial involvement, diagnostic imaging modalities, mortality and morbidity rates, and in particular treatment outcomes with open versus endovascular intervention. RESULTS: Sixty-two studies reporting on 85 cases of SAM were reviewed. Sixty-nine percent of cases were diagnosed histologically (24% on autopsy). Angiography was the most common form of diagnostic imaging modality (56% of cases). Arterial involvement was largely abdominal or cranial, with splenic arterial involvement being the most prevalent (29% of cases). There was a total SAM-related mortality of 26%. Endovascular intervention, most commonly in the form of coil embolization of aneurysmal vessel(s), was successful in 88% of cases where attempted, with no reported mortality. There was a mortality rate of 9% where open surgery was attempted. CONCLUSIONS: Catheter-based endovascular techniques can be a successful, minimally invasive treatment option in the management of this potentially life-threatening condition, and may also provide a temporary bailout measure in the acute phase before definitive surgical treatment at a later stage.

Initial findings and potential applicability of computational simulation of the aorta in acute type B dissection.

OBJECTIVE: Type B aortic dissection can be acutely complicated by rapid expansion, rupture, and malperfusion syndromes. Short-term adverse outcomes are associated with failure of the false lumen to thrombose. The reasons behind false lumen patency are poorly understood, and the objective of this pilot study was to use computational fluid dynamics reconstructions of aortic dissection cases to analyze the effect of aortic and primary tear morphology on flow characteristics and clinical outcomes in patients with acute type B dissections. METHODS: Three-dimensional patient-specific aortic dissection geometry was reconstructed from computed tomography scans of four patients presenting with acute type B aortic dissection and a further patient with sequential follow-up scans. The cases were selected based on their clinical presentation. Two were complicated by acute malperfusion that required emergency intervention. Three patients were uncomplicated and were managed conservatively. The patient-specific aortic models were used in computational simulations to assess the effect of aortic tear morphology on various parameters including flow, velocity, shear stress, and turbulence. RESULTS: Pulsatile flow simulation results showed that flow rate into the false lumen was dependent on both the size and position of the primary tear. Linear regression analysis demonstrated a significant relationship between percentage flow entering the false lumen and the size of the primary entry tear and an inverse relationship between false lumen flow and the site of the entry tear. Subjects complicated by malperfusion had larger-dimension entry tears than the uncomplicated cases (93% and 82% compared with 32% and 55%, respectively). Blood flow, wall shear stress, and turbulence levels varied significantly between subjects depending on aortic geometry. Highest wall shear stress (>7 Pa) was located at the tear edge, and progression of false lumen thrombosis was associated with prolonged particle residence times. CONCLUSIONS: Results obtained from this preliminary work suggest that aortic morphology and primary entry tear size and position exert significant effects on flow and other hemodynamic parameters in the dissected aorta in this preliminary work. Blood flow into the false lumen increases with increasing tear size and proximal location. Morphologic analysis coupled with computational fluid dynamic modeling may be useful in predicting acute type B dissection behavior allowing for selection of proper treatment modalities, and further confirmatory studies are warranted.

Improved catheter navigation with 3D electromagnetic guidance.

PURPOSE: To evaluate the in vitro performance of an electromagnetic navigation system (ENS) in aortic arch branch cannulation and describe its role for fenestrated endograft deployment. METHODS: Reconstructed multidetector computed tomography images of silicone phantoms representing the aortic arch and a thoracoabdominal aortic aneurysm were uploaded onto the StealthStation workstation, which provided 3-dimensional visualization of a guidewire by tracking sensors on its tip. For the evaluation of aortic arch branch cannulation, 9 operators were asked to cannulate the phantom's common carotid and left subclavian arteries using the (1) ENS, (2) a 2-dimensional (2D) screen setting simulating fluoroscopy, and (3) both imaging modalities. Analysis included procedure times, number of wall hits, and the Imperial College Complex Cannulation Scoring Tool (IC3ST) qualitative performance score. To evaluate the ability of the ENS during positioning of a fenestrated stent-graft over the visceral segment, a custom-made 4-vessel fenestrated stent-graft with sensors on the fenestrations was deployed 5 consecutive times using the ENS as the exclusive imaging technique. RESULTS: In the aortic arch model, cannulation times were significantly longer in the ENS group. However, compared with the 2D version, using both imaging modalities reduced fluoroscopic times [median 26.5 seconds (IQR 19.7-30.7) vs. 87 seconds (IQR 64-128), p<0.0001] and wall hits [median 8.5 (IQR 16-38) vs. 14 (IQR 11-160, p<0.05), while improving IC3ST performance scores [31/35 (IQR 30-31.2) vs. 25/35 (IQR 24-27), p<0.05]. Following deployment of the endograft with tracked fenestrations, the 4 visceral vessels were cannulated in all cases using only the ENS. CONCLUSION: The use of the ENS as a complementary imaging modality might be beneficial in terms of radiation exposure, cannulation performance, and positioning of intravascular devices.

In vitro fenestration of aortic stent-grafts: implications of puncture methods for in situ fenestration durability.

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.

Robot-assisted fenestrated endovascular aneurysm repair (FEVAR) using the Magellan system.

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.

Ruptured subclavian artery pseudoaneurysm following a shoulder massage on a background of clavicle non-union.

We present an unusual case of ruptured subclavian artery pseudoaneurysm following hydrotherapy and shoulder massage session on a background of clavicle non-union.Following a clavicle fracture 16 years ago, which was managed conservatively, a woman in her 30s presents over a decade later with a ruptured subclavian artery pseudoaneurysm.The original midshaft clavicle fracture was sustained 16 years ago. Conservative management was agreed, and she was discharged. Six years ago, she developed a small subclavian artery pseudoaneurysm which was kept under surveillance for 12 months with no active intervention required.Over the following years, she continued to have intermittent shoulder girdle discomfort and neuropathic symptoms. On this presentation, after a sports massage, she presented with rapid-onset supraclavicular and axillary swelling. This was diagnosed as a ruptured subclavian artery pseudoaneurysm and was treated with emergency radiological-guided stenting and subsequent internal fixation of the clavicle non-union.The patient then attended regular orthopaedic and vascular follow-up to ensure her clavicle fracture unites and the graft remains patent.We discuss the case presentation and management of this unusual injury.

In-Vivo Validation of a Novel Robotic Platform for Endovascular Intervention.

OBJECTIVE: In-vivo validation on animal setting of a pneumatically propelled robot for endovascular intervention, to determine safety and clinical advantage of robotic cannulations compared to manual operation. METHODS: Robotic assistance and image-guided intervention are increasingly used for improving endovascular procedures with enhanced navigation dexterity and accuracy. However, most platforms developed in the past decade still present inherent limitations in terms of altered clinical workflow, counterintuitive human-robot interaction, and a lack of versatility. We have created a versatile, highly integrated platform for robot-assisted endovascular intervention aimed at addressing such limitations, and here we demonstrate its clinical usability through in-vivo animal trials. A detailed in-vivo study on four porcine models conducted with our robotic platform is reported, involving cannulation and balloon angioplasty of five target arteries. RESULTS: The trials showed a 100% success rate, and post-mortem histopathological assessment demonstrated a reduction in the incidence and severity of vessel trauma with robotic navigation versus manual manipulation. CONCLUSION: In-vivo experiments demonstrated that the applicability of our robotic system within the context of this study was well tolerated, with good feasibility, and low risk profile. Comparable results were observed with robotics and manual cannulation, with clinical outcome potentially in favor of robotics. SIGNIFICANCE: This study showed that the proposed robotic platform can potentially improve the execution of endovascular procedures, paving the way for clinical translation.