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.
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.
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.
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.
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%).
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.
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.
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.
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.
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.
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 report the initial clinical use of a robotically steerable catheter during endovascular aneurysm repair (EVAR) in order to assess this novel and innovative approach in a clinical setting.
...Technique:
Following a series of in-vitro studies and procedure rehearsals using a pulsatile silicon aneurysm model, a 78-year-old man underwent robot-assisted EVAR of a 5.9-cm infrarenal abdominal aortic aneurysm. During the standard procedure, a 14-F remotely steerable robotic catheter was used to successfully navigate through the aneurysm sac, cannulate the contralateral limb of a bifurcated stent-graft under fluoroscopic guidance, and place stiff wires using fine and controlled movements. The procedure was completed successfully. There were no postoperative complications, and computed tomographic angiography prior to discharge and at 3 months confirmed that the stent-graft remained in good position, with no evidence of an endoleak.
Conclusion:
EVAR using robotically-steerable catheters is feasible. This technology may simplify more complex procedures by increasing the accuracy of vessel cannulation and perhaps reduce procedure times and radiation exposure to the patient and operator.
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 (
n
=
6
) and novices (
n
=
6
), 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.
To attempt to quantify the effect of varying degrees of iliac tortuosity on maneuverability and "torquability" of endovascular catheters in the visceral segment, comparing conventional and robotic ...cannulation techniques.
In a fenestrated endograft within a pulsatile phantom, 10 experienced operators cannulated the renal arteries via three different access vessels of varying iliac tortuosity with the use of conventional and robotic techniques. All procedures were performed in the angiography suite and recorded for blinded video assessment for quantitative (time, catheter-tip movements) and qualitative metrics (operator performance scores).
In total, 120 cannulations were observed. With increasing iliac tortuosity, median time and number of catheter movements required for renal cannulation with conventional techniques increased in stepwise fashion for mild, moderate, and severe iliac tortuosity (times, 7.6 min interquartile range (IQR), 4.6-9.3 min vs 6.9 min 4.2-11.4 min vs 17.7 min 13.3-22.6 min, respectively; movements, 184 IQR, 110-351 vs 251 207-395 vs 569 409-616, respectively). Median renal cannulation times were significantly reduced with the use of the robotic system irrespective of mild, moderate, or severe tortuosity (times, 1.4 min IQR, 1.1-1.9 min vs 3 min 2.3-3.3 min vs 2.8 min 1.5-3.9 min, respectively; movements, 19 IQR, 14-27 vs 46 43-58 vs 45 40-66, respectively; P < .005). Overall operator performance scores improved significantly with the use of the robotic system irrespective of iliac tortuosity severity.
In cases of moderate to severe iliac tortuosity, conventional catheter manipulation and control becomes an issue. The improvement in positional control and predictability seen with advanced catheter designs may be amplified in cases of severe iliac tortuosity.
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