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.

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.

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.

Multiple sclerosis, lymphoma and nasopharyngeal carcinoma: the central role of Epstein-Barr virus?

BACKGROUND: Multiple sclerosis (MS) and Hodgkin lymphoma (HL) share epidemiologic characteristics suggesting a possible common etiology. Epstein-Barr virus (EBV) is associated with HL, Burkitt lymphoma, some varieties of non-Hodgkin lymphoma (NHL) and nasopharyngeal carcinoma (NPC). METHOD: Patients were located through MS databases for (a) Barking and Havering, NE London; catchment approximately 400,000; MS patient number 751, and (b) Nottingham, catchment approximately 2,000,000; MS patient number 1,236. Search was undertaken for lymphoma or NPC and diagnosis of MS verified by McDonald criteria. RESULTS: We identified five UK-born and resident patients of interest: (1) male with onset HL aged 20 years developing relapsing-remitting MS 11 years later; (2) female with severe relapsing-remitting MS whose partner developed NHL, 5 years after MS diagnosis; (3) female with secondary progressive MS beginning at age 38 years who developed NHL 25 years later; (4) female diagnosed with MS aged 19 years who developed HL 4 years later, and (5) female with hereditary motor and sensory neuropathy developing cervical cancer at the age of 32 years, NPC at 33 years, and RR MS at 36 years. CONCLUSION: Our study supports a possible association between MS, HL, NHL, and perhaps NPC all of which are associated with EBV infection.

Comparison of manual versus robot-assisted contralateral gate cannulation in patients undergoing endovascular aneurysm repair.

PURPOSE: Robotic endovascular technology may offer advantages over conventional manual catheter techniques. Our aim was to compare the endovascular catheter path-length (PL) for robotic versus manual contralateral gate cannulation during endovascular aneurysm repair (EVAR), using video motion analysis (VMA). METHODS: This was a multicentre retrospective cohort study with fluoroscopic video recordings of 24 EVAR cases (14 robotic, 10 manual) performed by experienced operators (> 50 procedures), obtained from four leading European centres. Groups were comparable with no statistically significant differences in aneurysm size (p = 0.47) or vessel tortuosity (p = 0.68). Two trained assessors used VMA to calculate the catheter PL during contralateral gate cannulation for robotic versus manual approaches. RESULTS: There was a high degree of inter-observer reliability (Cronbach's α > 0.99) for VMA. Median robotic PL was 35.7 cm [interquartile range, IQR (30.8-51.0)] versus 74.1 cm [IQR (44.3-170.4)] for manual cannulation, p = 0.019. Robotic cases had a median cannulation time of 5.33 min [IQR (4.58-6.49)] versus 1.24 min [IQR (1.13-1.35)] in manual cases (p = 0.0083). Generated efficiency ratios (PL/aorto-iliac centrelines) was 1.6 (1.2-2.1) in robotic cases versus 2.6 (1.7-7.0) in manual, p = 0.031. CONCLUSION: Robot-assisted contralateral gate cannulation in EVAR leads to decreased navigation path lengths and increased economy of movement compared with manual catheter techniques. The benefit could be maximised by prioritising robotic catheter shaping over habituated reliance on guidewire manipulation. Robotic technology has the potential to reduce the endovascular footprint during manipulations even for experienced operators with the added advantage of zero radiation exposure.

Endovascular robotics.

The current state and the future direction.

Video motion analysis in live coronary angiography differentiates levels of experience and provides a novel method of skill assessment.

AIMS: Video motion analysis (VMA) uses fluoroscopic sequences to derive catheter and guidewire movement, and is able to calculate 2D catheter-tip path length (PL) on the basis of frame-by-frame pixel coordinates. The objective of this study was to validate VMA in coronary angiography as a method of skill assessment. METHODS AND RESULTS: Forty-seven coronary interventions performed by 10 low- (<1,000 cases; group A), five medium- (1,000-4,000; group B) and six high- (>4,000; group C) experience-volume cardiologists were prospectively recorded and analysed using VMA software. Total PL was calculated and procedure, fluoroscopy times, and radiation dose were recorded. Comparisons of PL were made between groups of experience. Groups A, B and C performed 24, 14 and 6 paired (right and left coronary) cannulations, respectively. Calculation of PL was possible in all recorded cases and significantly correlated with procedure (p=<0.001, rho=0.827) and fluoroscopy times (p=<0.001, rho=0.888). Median total path length (combined right and left coronaries) was significantly shorter in group C which used 3,836 pixels of movement (IQR: 3,003-4,484) vs. 10,556 (7,242-31,408) in group A (p=<0.001) and 8,725 (5,187-15,150) in group B (p=0.013). CONCLUSIONS: VMA in coronary angiography is feasible and PL is able to differentiate levels of experience.

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

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

Endovascular repair of ruptured abdominal aortic aneurysm: technical and team training in an immersive virtual reality environment.

PURPOSE: This study evaluates a fully immersive simulated angiosuite for training and assessment of technical endovascular and human factor skills during a crisis scenario. MATERIALS AND METHODS: Virtual reality (VIST-C, Mentice) simulators were integrated into a simulated angiosuite (ORCAMP, Orzone). Teams, lead by experienced (N = 5) or trainee (N = 5) endovascular specialists, performed simulated endovascular ruptured aortic aneurysm repair (rEVAR). Timed performance metrics were recorded as surrogate measures of performance. Participants (N = 22) completed postprocedure questionnaires evaluating face validity, as well as technical and human factor aspects, of the simulation on a Likert scale from 1 (not at all) to 5 (very much). RESULTS: Experienced team leaders were significantly faster than trainees in obtaining proximal control with an intra-aortic occlusion balloon (352 vs. 501 s, p = 0.047) and all completed the procedure within the allotted time, whilst no trainee was able to do so. Total fluoroscopy times were significantly lower in the experienced group (782 vs. 1,086 s, p = 0.016). Realism of the simulated angiosuite was scored highly by experienced team leaders (median 4/5, IQR 4-5). Participants found the simulation useful for acquiring technical (4/5, IQR 4-5) and communication skills (4/5, IQR 4-5) and particularly valuable for enhancing teamwork (5/5, IQR 4-5) and patient safety (5/5, IQR 4-5). CONCLUSION: This study shows feasibility of creation of a crisis scenario in a fully immersive angiosuite simulation and team performance of a simulated rEVAR. Performance metrics differentiated between experienced specialists and trainees, and the realism of the simulation exercise and environment were rated highly by experienced endovascular specialists. This simulation has potential as a powerful training and assessment tool with opportunities to improve team performance in rEVAR through both technical and human factor skills training.