Publications
116 results found
Bakhsh A, Martin GFJ, Bicknell CD, et al., 2018, An Evaluation of the Impact of High-Fidelity Endovascular Simulation on Surgeon Stress and Technical Performance, JOURNAL OF SURGICAL EDUCATION, Vol: 76, Pages: 864-871, ISSN: 1931-7204
- Author Web Link
- Cite
- Citations: 13
Normahani P, Kwasnicki R, Bicknell C, et al., 2018, Wearable sensor technology efficacy in peripheral vascular disease (wSTEP): a randomized controlled trial, Annals of Surgery, Vol: 268, Pages: 1113-1118, ISSN: 1528-1140
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.
Doyen B, Bicknell CD, Riga CV, et al., 2018, Evidence Based Training Strategies to Improve Clinical Practice in Endovascular Aneurysm Repair, EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY, Vol: 56, Pages: 751-758, ISSN: 1078-5884
- Author Web Link
- Cite
- Citations: 3
Martin G, Pettengell C, John I, et al., 2018, What Do Patients Want to Know About Their Surgeon? Stakeholder Views of Surgeon-Specific Mortality Data, 45th Annual VEITHSymposium, Publisher: MOSBY-ELSEVIER, Pages: E161-E161, ISSN: 0741-5214
Zheng J-Q, Zhou X-Y, Riga C, et al., 2018, 3D path planning from a single 2D fluoroscopic image for robot assisted fenestrated endovascular aortic repair, Publisher: arXiv
The current standard of intra-operative navigation during FenestratedEndovascular Aortic Repair (FEVAR) calls for need of 3D alignments betweeninserted devices and aortic branches. The navigation commonly via 2Dfluoroscopic images, lacks anatomical information, resulting in longeroperation hours and radiation exposure. In this paper, a framework forreal-time 3D robotic path planning from a single 2D fluoroscopic image ofAbdominal Aortic Aneurysm (AAA) is introduced. A graph matching method isproposed to establish the correspondence between the 3D preoperative and 2Dintra-operative AAA skeletons, and then the two skeletons are registered byskeleton deformation and regularization in respect to skeleton length andsmoothness. Furthermore, deep learning was used to segment 3D pre-operative AAAfrom Computed Tomography (CT) scans to facilitate the framework automation.Simulation, phantom and patient AAA data sets have been used to validate theproposed framework. 3D distance error of 2mm was achieved in the phantom setup.Performance advantages were also achieved in terms of accuracy, robustness andtime-efficiency. All the code will be open source.
Rolls A, Riga C, 2018, Endovascular robotics The current state and the future direction, ANNALS OF THE ROYAL COLLEGE OF SURGEONS OF ENGLAND, Vol: 100, Pages: 14-+, ISSN: 0035-8843
- Author Web Link
- Cite
- Citations: 5
Li MM, Hamady MS, Bicknell CD, et al., 2018, Flexible robotic catheters in the visceral segment of the aorta: advantages and limitations, JOURNAL OF CARDIOVASCULAR SURGERY, Vol: 59, Pages: 317-321, ISSN: 0021-9509
Rolls AE, Bicknell CD, Cheshire NJ, et al., 2018, Recent developments in vascular robotics, Journal of Cardiovascular Surgery, Vol: 59, Pages: 307-309, ISSN: 1827-191X
Chi W, Liu J, Rafii-Tari H, et al., 2018, Learning-based endovascular navigation through the use of non-rigid registration for collaborative robotic catheterization, INTERNATIONAL JOURNAL OF COMPUTER ASSISTED RADIOLOGY AND SURGERY, Vol: 13, Pages: 855-864, ISSN: 1861-6410
PurposeEndovascular intervention is limited by two-dimensional intraoperative imaging and prolonged procedure times in the presence of complex anatomies. Robotic catheter technology could offer benefits such as reduced radiation exposure to the clinician and improved intravascular navigation. Incorporating three-dimensional preoperative imaging into a semiautonomous robotic catheterization platform has the potential for safer and more precise navigation. This paper discusses a semiautonomous robotic catheter platform based on previous work (Rafii-Tari et al., in: MICCAI2013, pp 369–377. https://doi.org/10.1007/978-3-642-40763-5_46, 2013) by proposing a method to address anatomical variability among aortic arches. It incorporates anatomical information in the process of catheter trajectories optimization, hence can adapt to the scale and orientation differences among patient-specific anatomies.MethodsStatistical modeling is implemented to encode the catheter motions of both proximal and distal sites based on cannulation data obtained from a single phantom by an expert operator. Non-rigid registration is applied to obtain a warping function to map catheter tip trajectories into other anatomically similar but shape/scale/orientation different models. The remapped trajectories were used to generate robot trajectories to conduct a collaborative cannulation task under flow simulations. Cross-validations were performed to test the performance of the non-rigid registration. Success rates of the cannulation task executed by the robotic platform were measured. The quality of the catheterization was also assessed using performance metrics for manual and robotic approaches. Furthermore, the contact forces between the instruments and the phantoms were measured and compared for both approaches.ResultsThe success rate for semiautomatic cannulation is 98.1% under dry simulation and 94.4% under continuous flow simulation. The proposed robotic approach achieved smoother cathete
Zheng J-Q, Zhou X-Y, Li Q-B, et al., 2018, Abdominal aortic aneurysm segmentation with a small number of training subjects, Publisher: arXiv
Pre-operative Abdominal Aortic Aneurysm (AAA) 3D shape is critical forcustomized stent-graft design in Fenestrated Endovascular Aortic Repair(FEVAR). Traditional segmentation approaches implement expert-designed featureextractors while recent deep neural networks extract features automaticallywith multiple non-linear modules. Usually, a large training dataset isessential for applying deep learning on AAA segmentation. In this paper, theAAA was segmented using U-net with a small number (two) of training subjects.Firstly, Computed Tomography Angiography (CTA) slices were augmented with grayvalue variation and translation to avoid the overfitting caused by the smallnumber of training subjects. Then, U-net was trained to segment the AAA. DiceSimilarity Coefficients (DSCs) over 0.8 were achieved on the testing subjects.The PLZ, DLZ and aortic branches are all reconstructed reasonably, which willfacilitate stent graft customization and help shape instantiation forintra-operative surgery navigation in FEVAR.
Rueda MA, Riga C, Hamady MS, 2018, Flexible robotics in pelvic disease: what pathologies? Does the catheter increase applicability of embolic therapy?, J Cardiovasc Surg (Torino)
Interventional Radiology procedures, equipment and techniques as well as image guidance have developed dramatically over the last few decades. The evidence for minimally invasive interventions in vascular and oncology fields is rapidly growing and several procedures are considered the first line management. However, radiation exposure, image guidance and innovative solutions to known anatomical challenges are still lagging behind. Robotic technology and its role in surgery have been developing at a steady speed. Endovascular robotics are following suit with a different set of problems and targets. This article discusses the advances and limitations in one aspects of endovascular robotic, namely pelvic pathology that includes aneurysms, fibroids, benign prostatic hypertrophy and vascular malformation.
Lim CS, Dhutia A, Riga C, et al., 2018, Two-vessel branched stent graft for severely angulated aortic arch aneurysm in a Jehovah's Witness, Vascular and Endovascular Surgery, Vol: 52, Pages: 154-158, ISSN: 1538-5744
Aneurysmal disease involving the origins of supra aortic vessels often requires complex open and/or endovascular repair that is not only associated with significant risk of mortality and morbidity but also often with perioperative blood loss requiring transfusion. We report a successful repair of a large thoracic aortic aneurysm (TAA) involving the aortic arch with a custom-made Bolton Relay 2-vessel branched thoracic aortic endograft in a 42-year-old Jehovah’s Witness who would otherwise be very unlikely to survive an open repair. Branched thoracic aortic endografting offers a potentially safe, minimally invasive, and effective alternative for TAA disease involving the supra-aortic arteries, especially in patients who are at high risk of open surgery.
Zhou X, Lin J, Riga C, et al., 2018, Real-time 3D shape instantiation from single fluoroscopy projection for fenestrated stent graft deployment, IEEE Robotics and Automation Letters, Vol: 3, Pages: 1314-1321, ISSN: 2377-3766
Robot-assisted deployment of fenestrated stent grafts in Fenestrated Endovascular Aortic Repair (FEVAR) requires accurate geometrical alignment. Currently, this process is guided by 2D fluoroscopy, which is uninformative and error prone. In this paper, a real-time framework is proposed to instantiate the 3D shape of a fenestrated stent graft utilizing only a single low-dose 2D fluoroscopic image. Firstly, the fenestrated stent graft was placed with markers. Secondly, the 3D pose of each stent segment was instantiated by the RPnP (Robust Perspective-n-Point) method. Thirdly, the 3D shape of the whole stent graft was instantiated via graft gap interpolation. Focal-Unet was proposed to segment the markers from 2D fluoroscopic images to achieve semi-automatic marker detection. The proposed framework was validated on five patient-specific 3D printed phantoms of aortic aneurysms and three stent grafts with new marker placements, showing an average distance error of 1-3mm and an average angle error of 4 degrees.
Rolls AE, Riga CV, Rahim S, et al., 2017, Video motion analysis in live coronary angiography differentiates levels of experience and provides a novel method of skill assessment, Eurointervention, Vol: 13, Pages: E1460-E1467, ISSN: 1774-024X
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.
Lear R, Godfrey AD, Riga C, et al., 2017, Surgeons' Perceptions of the Causes of Preventable Harm in Arterial Surgery: A Mixed-Methods Study, European Journal of Vascular and Endovascular Surgery, Vol: 54, Pages: 778-786, ISSN: 1078-5884
BackgroundSystem 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.MethodsVascular 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.ResultsSeventy-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 interview
Chi W, Rafii-Tari H, Payne CJ, et al., 2017, A learning based training and skill assessment platform with haptic guidance for endovascular catheterization, 2017 IEEE International Conference on Robotics and Automation (ICRA), Publisher: IEEE, Pages: 2357-2363, ISSN: 1050-4729
Increasing demands in endovascular intervention have motivated technical skill training and competency-based measures of performance. However, there are no well-established online metrics for technical skill assessment; few studies have explored operator behavioral patterns from catheter motion and operator hand motions. This paper proposes a platform for active online training and objective assessment of endovascular skills, through learning optimum catheter motions from multiple demonstrations. An ungrounded hand-held haptic device for providing intuitive haptic guidance to novice users based on this learnt information is also proposed. Statistical models are implemented to extract the underlying catheter motion patterns, and utilize them for performance evaluation and haptic guidance. The results show significant improvements in endovascular navigation for inexperienced operators. Finer catheter motions were achieved with the provided haptic guidance. The results suggest that the proposed platform can be integrated into current clinical training setups, and motivate the improvement of endovascular training platforms with better realism.
Lear R, Godfrey AD, Riga C, et al., 2017, The impact of system factors on quality and safety in arterial surgery: a systematic review, European Journal of Vascular and Endovascular Surgery, Vol: 54, Pages: 79-93, ISSN: 1078-5884
ObjectiveA systems approach to patient safety proposes that a wide range of factors contribute to surgical outcome, yet the impact of team, work environment, and organisational factors, is not fully understood in arterial surgery. The aim of this systematic review is to summarize and discuss what is already known about the impact of system factors on quality and safety in arterial surgery.Data sourcesA systematic review of original research papers in English using MEDLINE, Embase, PsycINFO, and Cochrane databases, was performed according to PRISMA guidelines.Review methodsIndependent reviewers selected papers according to strict inclusion and exclusion criteria, and using predefined data fields, extracted relevant data on team, work environment, and organisational factors, and measures of quality and/or safety, in arterial procedures.ResultsTwelve papers met the selection criteria. Study endpoints were not consistent between papers, and most failed to report their clinical significance. A variety of tools were used to measure team skills in five papers; only one paper measured the relationship between team factors and patient outcomes. Two papers reported that equipment failures were common and had a significant impact on operating room efficiency. The influence of hospital characteristics on failure-to-rescue rates was tested in one large study, although their conclusions were limited to the American Medicare population. Five papers implemented changes in the patient pathway, but most studies failed to account for potential confounding variables.ConclusionsA small number of heterogenous studies have evaluated the relationship between system factors and quality or safety in arterial surgery. There is some evidence of an association between system factors and patient outcomes, but there is more work to be done to fully understand this relationship. Future research would benefit from consistency in definitions, the use of validated assessment tools, measurement of cli
Perera AH, Riga CV, Monzon L, et al., 2017, Response to commentary on "Robotic Arch Catheter Placement Reduces Cerebral Embolisation During Thoracic Endovascular Aortic Repair (TEVAR)", European Journal of Vascular and Endovascular Surgery, Vol: 54, Pages: 126-127, ISSN: 1078-5884
Perera AH, Riga CV, Monzon L, et al., 2017, Robotic Arch Catheter Placement Reduces Cerebral Embolization During Thoracic Endovascular Aortic Repair (TEVAR), EUROPEAN JOURNAL OF VASCULAR AND ENDOVASCULAR SURGERY, Vol: 53, Pages: 362-369, ISSN: 1078-5884
Rafii-Tari H, Payne CJ, Bicknell C, et al., 2017, Objective Assessment of Endovascular Navigation Skills with Force Sensing, ANNALS OF BIOMEDICAL ENGINEERING, Vol: 45, Pages: 1315-1327, ISSN: 0090-6964
Despite the increasing popularity of endovascular intervention in clinical practice, there remains a lack of objective and quantitative metrics for skill evaluation of endovascular techniques. Data relating to the forces exerted during endovascular procedures and the behavioral patterns of endovascular clinicians is currently limited. This research proposes two platforms for measuring tool forces applied by operators and contact forces resulting from catheter–tissue interactions, as a means of providing accurate, objective metrics of operator skill within a realistic simulation environment. Operator manipulation patterns are compared across different experience levels performing various complex catheterization tasks, and different performance metrics relating to tool forces, catheter motion dynamics, and forces exerted on the vasculature are extracted. The results depict significant differences between the two experience groups in their force and motion patterns across different phases of the procedures, with support vector machine (SVM) classification showing cross-validation accuracies as high as 90% between the two skill levels. This is the first robust study, validated across a large pool of endovascular specialists, to present objective measures of endovascular skill based on exerted forces. The study also provides significant insights into the design of optimized metrics for improved training and performance assessment of catheterization tasks.
Desender L, Van Herzeele I, Lachat M, et al., 2017, A multicentre trial of patient specific rehearsal prior to EVAR: impact on procedural planning and team performance, European Journal of Vascular and Endovascular Surgery, Vol: 53, Pages: 354-361, ISSN: 1532-2165
OBJECTIVE: Patient specific rehearsal (PsR) prior to endovascular aneurysm repair (EVAR) enables the endovascular team to practice and evaluate the procedure prior to treating the real patient. This multicentre trial aimed to evaluate the utility of PsR prior to EVAR as a pre-operative planning and briefing tool. MATERIAL AND METHODS: Patients with an aneurysm suitable for EVAR were randomised to pre-operative or post-operative PsR. Before and after the PsR, the lead implanter completed a questionnaire to identify any deviation from the initial treatment plan. All team members completed a questionnaire evaluating realism, technical issues, and human factor aspects pertinent to PsR. Technical and human factor skills, and technical and clinical success rates were compared between the randomised groups. RESULTS: 100 patients were enrolled between September 2012 and June 2014. The plan to visualise proximal and distal landing zones was adapted in 27/50 (54%) and 38/50 (76%) cases, respectively. The choice of the main body, contralateral limb, or iliac extensions was adjusted in 8/50 (16%), 17/50 (34%), and 14/50 (28%) cases, respectively. At least one of the abovementioned parameters was changed in 44/50 (88%) cases. For 100 EVAR cases, 199 subjective questionnaires post-PsR were completed. PsR was considered to be useful for selecting the optimal C-arm angulation (median 4, IQR 4-5) and was recognised as a helpful tool for team preparation (median 4, IQR 4-4), to improve communication (median 4, IQR 3-4), and encourage confidence (median 4, IQR 3-4). Technical and human factor skills and technical and initial clinical success rates were similar between the randomisation groups. CONCLUSION: PsR prior to EVAR has a significant impact on the treatment plan and may be useful as a pre-operative planning and briefing tool. Subjective ratings indicate that this technology may facilitate planning of optimal C-arm angulation and improve non-technical skills. TRIAL REGISTRATION:
Smith R, Lee S, Bicknell C, et al., 2016, Examining the use of a novel dynamic endovascular simulator to facilitate intelligent localization and robotic technologies, The Vascular Societies’ ASM 2016
Lear R, Riga C, Godfrey AD, et al., 2016, Multicentre observational study of surgical system failures in aortic procedures and their effect on patient outcomes, British Journal of Surgery, Vol: 103, Pages: 1467-1475, ISSN: 1365-2168
BACKGROUND: Vascular surgical care has changed dramatically in recent years with little knowledge of the impact of system failures on patient safety. The primary aim of this multicentre observational study was to define the landscape of surgical system failures, errors and inefficiency (collectively termed failures) in aortic surgery. Secondary aims were to investigate determinants of these failures and their relationship with patient outcomes. METHODS: Twenty vascular teams at ten English hospitals trained in structured self-reporting of intraoperative failures (phase I). Failures occurring in open and endovascular aortic procedures were reported in phase II. Failure details (category, delay, consequence), demographic information (patient, procedure, team experience) and outcomes were reported. RESULTS: There were strong correlations between the trainer and teams for the number and type of failures recorded during 88 procedures in phase I. In 185 aortic procedures, teams reported a median of 3 (i.q.r. 2-6) failures per procedure. Most frequent failures related to equipment (unavailability, failure, configuration, desterilization). Most major failures related to communication. Fourteen failures directly harmed 12 patients. Significant predictors of an increased failure rate were: endovascular compared with open repair (incidence rate ratio (IRR) for open repair 0·71, 95 per cent c.i. 0·57 to 0·88; P = 0·002), thoracic aneurysms compared with other aortic pathologies (IRR 2·07, 1·39 to 3·08; P < 0·001) and unfamiliarity with equipment (IRR 1·52, 1·20 to 1·91; P < 0·001). The major failure total was associated with reoperation (P = 0·011), major complications (P = 0·029) and death (P = 0·027). CONCLUSION: Failure in aortic procedures is frequently caused by issues with team-wo
Pettengell C, Sharrock A, Nafisee D, et al., 2016, Endovascular non-technical skills assessment in trainees (Endo-OTAS), Vascular Societies Annual Scientific Meeting, Publisher: Wiley, Pages: 24-24, ISSN: 1365-2168
Godfrey AD, Riga C, Bicknell C, 2016, 750 preoperative elective aortic-conditioned for failure?, Vascular-Societies Annual Scientific Meeting, Publisher: Wiley, Pages: 14-14, ISSN: 1365-2168
Godfrey AD, Lear R, Riga C, et al., 2016, Analysis of 1180 NRLS patient safety events in elective aortic surgery, Vascular-Societies Annual Scientific Meeting, Publisher: WILEY-BLACKWELL, Pages: 14-14, ISSN: 0007-1323
Martin G, Riga C, Gibbs R, et al., 2016, Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair: A Benchmark for New Technologies, Journal of Endovascular Therapy, Vol: 23, Pages: 783-790, ISSN: 1545-1550
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 technic
Mazomenos EB, Chang PL, Rippel RA, et al., 2016, Catheter manipulation analysis for objective performance and technical skills assessment in transcatheter aortic valve implantation., International Journal of Computer Assisted Radiology and Surgery, Vol: 11, Pages: 1121-1131, ISSN: 1861-6410
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 e
Norman E, Harling M, Skervin AL, et al., 2016, Modified use of thoracic and iliac branch endografts to treat an abdominal aortic aneurysm with an unusually narrow neck, BJR Case Reports, Vol: 2, ISSN: 2055-7159
Abdominal aortic aneurysms with hostile anatomy are a recognized hindrance to the continuing application of endovascular aortic interventions. Narrowed aneurysm necks pose technical difficulties, particularly in the absence of customized endografts. There are multiple suggested approaches to overcome shortened and angulated necks endovascularly; however, none of these address narrowed necks. We present a case where an endograft was used outside of its “instruction for use” by combining the thoracic and iliac branch technologies to overcome this problem. Expanding the use of commercially available endografts for aortic aneurysms with hostile anatomy could have significant practical and financial benefits.
Chang P-L, Rolls A, De Praetere H, et al., 2016, Robust Catheter and Guidewire Tracking Using B-Spline Tube Model and Pixel-Wise Posteriors, IEEE Robotics and Automation Letters, Vol: 1, Pages: 303-308, ISSN: 2377-3766
In endovascular surgery and cardiology, robotic catheters are emerging as a promising technology for enhanced catheter manipulation and navigation while reducing radiation exposure. For robotic catheter systems especially with tendon actuation, a key challenge is the localisation of the catheter shape and position within the anatomy. An effective approach is through image-based catheter/guidewire detection and tracking. However, these are difficult problems due to the thin appearance of the instruments in the image and the low signal-to-noise ratio of fluoroscopy. In this letter, we propose a deformable B-spline tube model, which can effectively represent the shape of a catheter and guidewire. The model allows fitting using a region-based probabilistic algorithm, which does not rely on intensity gradients but exploits a signed distance function and the nonparametric distributions of measurements. Unlike previous B-spline fitting approaches, which optimise the spline with respect to control points, we propose a knot-driven scheme with an equidistance prior to better fit complex curves. Our probabilistic framework shows promising results for catheter and guidewire tracking in different procedures even with handling overlapping instrument segments. We present empirical studies using phantom model data and in vivo fluoroscopic sequences with annotated ground truth. Our results indicate that the proposed approach can precisely model the catheter and guidewire contours in near real time, and this information can be embedded in a robotic catheter control loop or utilised for image-guidance.
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.