Comparing the performance of conventional and robotic catheters in transcatheter aortic valve implantation

In this paper we investigate the performance of a recently developed robotic catheterization platform in comparison to conventional surgical equipment. Transcather aortic valve implantation (TAVI) was chosen as the test case and 12 interventionists (6 experts and 6 novices) participated in experiments with a silicon aorta model. Video sequences of the fluoroscopic monitor, used for guiding the instruments, were captured and processed with specialized software. To evaluate and compare the two systems the 2-D position of the catheter/guidewire tip is tracked and the shape of the phantom model is extracted in the video frames. In our analysis, we focus on three metrics; the procedure time, the average speed and the average distance to the vessel wall. The obtained results show that procedure time is capable of discriminating the participants of the different experience groups, achieving p=0.008 in the first stage of the experiment. In addition, experts consistently exhibit a higher average speed than novices. Ultimately, the increased average distance to the vessel wall demonstrated by the robotic system is an indication of improved precision and safer catheter/guidewire navigation

A Survey on the Current Status and Future Challenges Towards Objective Skills Assessment in Endovascular Surgery

Minimally-invasive endovascular interventions have evolved rapidly over the past decade, facilitated by breakthroughs in medical imaging and sensing, instrumentation and most recently robotics. Catheter based operations are potentially safer and applicable to a wider patient population due to the reduced comorbidity. As a result endovascular surgery has become the preferred treatment option for conditions previously treated with open surgery and as such the number of patients undergoing endovascular interventions is increasing every year. This fact coupled with a proclivity for reduced working hours, results in a requirement for efficient training and assessment of new surgeons, that deviates from the “see one, do one, teach one” model introduced by William Halsted, so that trainees obtain operational expertise in a shorter period. Developing more objective assessment tools based on quantitative metrics is now a recognised need in interventional training and this manuscript reports the current literature for endovascular skills assessment and the associated emerging technologies. A systematic search was performed on PubMed (MEDLINE), Google Scholar, IEEXplore and known journals using the keywords, “endovascular surgery”, “surgical skills”, “endovascular skills”, “surgical training endovascular” and “catheter skills”. Focusing explicitly on endovascular surgical skills, we group related works into three categories based on the metrics used; structured scales and checklists, simulation-based and motion-based metrics. This review highlights the key findings in each category and also provides suggestions for new research opportunities towards fully objective and automated surgical assessment solutions

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 (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

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

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

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