Characterising the incidence and mode of visceral stent failure after fenestrated endovascular aneurysm repair (FEVAR)

Background In FEVAR, visceral stents provide continuity and maintain perfusion between the main body of the stent and the respective visceral artery. The aim of this study was to characterise the incidence and mode of visceral stent failure (type Ic endoleak, type IIIa endoleak, stenosis/kink, fracture, crush and occlusion) after FEVAR in a large cohort of patients at a high-volume centre. Methods A retrospective review of visceral stents placed during FEVAR over 15 years (February 2003-December 2018) was performed. Kaplan-Meier analyses of freedom from visceral stent-related complications were performed. The outcomes between graft configurations of varying complexity were compared, as were the outcomes of different stent types and different visceral vessels. Results Visceral stent complications occurred in 47/236 patients (19.9%) and 54/653 stents (8.3%). Median follow up was 3.7 years (IQR 1.7–5.3 years). There was no difference in visceral stent complication rate between renal, SMA and coeliac arteries. Visceral stent complications were more frequent in more complex grafts compared to less complex grafts. Visceral stent complications were more frequent in uncovered stents compared to covered stents. Visceral stent-related endoleaks (type Ic and type IIIa) occurred exclusively around renal artery stents. The most common modes of failure with SMA stents were kinking and fracture, whereas with coeliac artery stents it was external crush. Conclusion Visceral stent complications after FEVAR are common and merit continued and close long-term surveillance. The mode of visceral stent failure varies across the vessels in which the stents are located

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

Carotid artery stenting: the 2011 NICE guidelines

Atherosclerotic disease of the carotid bifurcation is associated with an increased risk of both stroke and transient ischaemic attack. Carotid artery stenting (CAS) offers an alternative approach to carotid endarterectomy (CEA) in both symptomatic and asymptomatic individuals. The National Institute for Health and Clinical excellence (NICE) guidance for CAS in symptomatic subjects supports CAS with some caveats. The procedure should be carried out by an experienced clinical team with a good track record and there should be careful attention to audit and long-term follow-up. The case for CAS in asymptomatic carotid artery stenosis is not yet proved. For asymptomatic disease, NICE recommends that where CEA and CAS are clinically appropriate and technically feasible, patients should be randomised within the second Asymptomatic Carotid Surgery Trial (ACST-2)

Worldwide CAS Practice in 2011

Stroke prevention is a major public health priority; best medical therapy for patients who are at risk of atherosclerosis reduces their risk of stroke. In patients with tight carotid artery stenosis, the risk of subsequent stroke is significantly reduced by removing the atherosclerotic plaque. Carotid endarterectomy (CEA) has been available for more than 50 years and has, to date, been the standard treatment for significant carotid stenosis in symptomatic and asymptomatic patients. Carotid artery stenting (CAS) is a new and effective treatment that avoids the pain and morbidity associated with surgery. A number of trials have compared CAS with CEA, and although both procedures have a real risk of perioperative stroke, recent randomized trials have highlighted an increased risk of minor stroke with CAS and an increased risk of perioperative myocardial infarction with CEA. Cranial nerve injury and access site hematoma requiring return to the operating room or an unexpected increase in the level of care are significantly greater after CEA, while contrast related issues are a consideration for CAS. Clinical trials have not yet provided clear evidence of superiority of either treatment for “standard operative risk” patients and have been criticized for their design, patient selection, and very variable physician training and credentialing. This article describes the main messages of current guidelines for CAS from the European Society for Vascular Surgery (ESVS) (2009), the American Heart Association (AHA) (2011), and the UK National Institute for Clinical Excellence (NICE) (2011). The ESVS and the AHA guideline documents are large consensus documents covering a wide range of topics related to the management of carotid disease, whereas NICE guidelines are specific to CAS. The extracts in this article summarize the messages from these guidelines.</p

Worldwide CAS Practice in 2011

Stroke prevention is a major public health priority; best medical therapy for patients who are at risk of atherosclerosis reduces their risk of stroke. In patients with tight carotid artery stenosis, the risk of subsequent stroke is significantly reduced by removing the atherosclerotic plaque. Carotid endarterectomy (CEA) has been available for more than 50 years and has, to date, been the standard treatment for significant carotid stenosis in symptomatic and asymptomatic patients. Carotid artery stenting (CAS) is a new and effective treatment that avoids the pain and morbidity associated with surgery. A number of trials have compared CAS with CEA, and although both procedures have a real risk of perioperative stroke, recent randomized trials have highlighted an increased risk of minor stroke with CAS and an increased risk of perioperative myocardial infarction with CEA. Cranial nerve injury and access site hematoma requiring return to the operating room or an unexpected increase in the level of care are significantly greater after CEA, while contrast related issues are a consideration for CAS. Clinical trials have not yet provided clear evidence of superiority of either treatment for “standard operative risk” patients and have been criticized for their design, patient selection, and very variable physician training and credentialing. This article describes the main messages of current guidelines for CAS from the European Society for Vascular Surgery (ESVS) (2009), the American Heart Association (AHA) (2011), and the UK National Institute for Clinical Excellence (NICE) (2011). The ESVS and the AHA guideline documents are large consensus documents covering a wide range of topics related to the management of carotid disease, whereas NICE guidelines are specific to CAS. The extracts in this article summarize the messages from these guidelines.</p

The difficult venous ulcer: case series of 177 ulcers referred for vascular surgical opinion following failure of conservative management.

Venous leg ulcers are common, chronic, debilitating, and expensive. Evidence supports use of compression bandaging, with superficial venous surgery in selected cases, but these interventions frequently fail to achieve healing. We describe a series of 152 consecutive referrals from a nurse-led specialist dermatology clinic to a vascular surgical service; a group posing particularly challenging problems. This observational study, with median follow-up of 18 months, describes outcomes in a number of important clinically identifiable subgroups. Its findings may assist service planning and discussion of the surgical role within multidisciplinary ulcer management

Evaluating training for a simulated team in complex whole procedure simulations in the endovascular suite

Introduction: Simulators supporting the development of technical skills for complex procedures are gaining prominence. Safe performance of complex procedures requires effective team interactions. Our research group creates ‘whole’ procedure simulations to produce the psychological fidelity of clinical settings. Recruitment of real interventional team (IT) members has proved challenging. Actors as a simulated team are expensive. We hypothesised that medical students and trainees in a vascular unit could authentically portray members of the endovascular suite for carotid stenting. Methods: This paper describes the evaluation of a training programme for a simulated IT. Participants rated the extent to which programmes objectives were met and realism of simulations. Researchers’ field notes provided insight into strengths and weaknesses of the programme. Results: Seven members from the vascular unit undertook training. Learning objectives were largely met. Nineteen simulations with 13 interventionalists were performed. Realism levels were at least moderate. Simulated IT members reported increased understanding of teamwork and roles in the endovascular suite. Discussion: A simulated IT proved feasible. Authentic psychological fidelity complemented the physical fidelity of the simulated suite. Although there were areas for development in training, this approach might contribute considerably to interventionalist training and increase knowledge and skills of vascular trainees and medical students