Outcomes After Endovascular Aortic Intervention in Patients With Connective Tissue Disease

IMPORTANCE

Endovascular treatment is not recommended for aortic pathologies in patients with connective tissue diseases (CTDs) other than in redo operations and as bridging procedures in emergencies. However, recent developments in endovascular technology may challenge this dogma.

OBJECTIVE

To assess the midterm outcomes of endovascular aortic repair in patients with CTD.

DESIGN, SETTING, AND PARTICIPANTS

For this descriptive retrospective study, data on demographics, interventions, and short-term and midterm outcomes were collected from 18 aortic centers in Europe, Asia, North America, and New Zealand. Patients with CTD who had undergone endovascular aortic repair from 2005 to 2020 were included. Data were analyzed from December 2021 to November 2022.

EXPOSURE

All principal endovascular aortic repairs, including redo surgery and complex repairs of the aortic arch and visceral aorta.

MAIN OUTCOMES AND MEASURES

Short-term and midterm survival, rates of secondary procedures, and conversion to open repair.

RESULTS

In total, 171 patients were included: 142 with Marfan syndrome, 17 with Loeys-Dietz syndrome, and 12 with vascular Ehlers-Danlos syndrome (vEDS). Median (IQR) age was 49.9 years (37.9-59.0), and 107 patients (62.6%) were male. One hundred fifty-two (88.9%) were treated for aortic dissections and 19 (11.1%) for degenerative aneurysms. One hundred thirty-six patients (79.5%) had undergone open aortic surgery before the index endovascular repair. In 74 patients (43.3%), arch and/or visceral branches were included in the repair. Primary technical success was achieved in 168 patients (98.2%), and 30-day mortality was 2.9% (5 patients). Survival at 1 and 5 years was 96.2% and 80.6% for Marfan syndrome, 93.8% and 85.2% for Loeys-Dietz syndrome, and 75.0% and 43.8% for vEDS, respectively. After a median (IQR) follow-up of 4.7 years (1.9-9.2), 91 patients (53.2%) had undergone secondary procedures, of which 14 (8.2%) were open conversions.

CONCLUSIONS AND RELEVANCE

This study found that endovascular aortic interventions, including redo procedures and complex repairs of the aortic arch and visceral aorta, in patients with CTD had a high rate of early technical success, low perioperative mortality, and a midterm survival rate comparable with reports of open aortic surgery in patients with CTD. The rate of secondary procedures was high, but few patients required conversion to open repair. Improvements in devices and techniques, as well as ongoing follow-up, may result in endovascular treatment for patients with CTD being included in guideline recommendations.

Ruptured subclavian artery pseudoaneurysm following a shoulder massage on a background of clavicle non-union

We present an unusual case of ruptured subclavian artery pseudoaneurysm following hydrotherapy and shoulder massage session on a background of clavicle non-union.Following a clavicle fracture 16 years ago, which was managed conservatively, a woman in her 30s presents over a decade later with a ruptured subclavian artery pseudoaneurysm.The original midshaft clavicle fracture was sustained 16 years ago. Conservative management was agreed, and she was discharged. Six years ago, she developed a small subclavian artery pseudoaneurysm which was kept under surveillance for 12 months with no active intervention required.Over the following years, she continued to have intermittent shoulder girdle discomfort and neuropathic symptoms. On this presentation, after a sports massage, she presented with rapid-onset supraclavicular and axillary swelling. This was diagnosed as a ruptured subclavian artery pseudoaneurysm and was treated with emergency radiological-guided stenting and subsequent internal fixation of the clavicle non-union.The patient then attended regular orthopaedic and vascular follow-up to ensure her clavicle fracture unites and the graft remains patent.We discuss the case presentation and management of this unusual injury.

In-vivo Validation of a Novel Robotic Platform for Endovascular Intervention

OBJECTIVE

In-vivo validation on animal setting of a pneumatically propelled robot for endovascular intervention, to determine safety and clinical advantage of robotic cannulations compared to manual operation.

METHODS

Robotic assistance and image-guided intervention are increasingly used for improving endovascular procedures with enhanced navigation dexterity and accuracy. However, most platforms developed in the past decade still present inherent limitations in terms of altered clinical workflow, counterintuitive human-robot interaction, and a lack of versatility. We have created a versatile, highly integrated platform for robot-assisted endovascular intervention aimed at addressing such limitations, and here we demonstrate its clinical usability through in-vivo animal trials. A detailed in-vivo study on four porcine models conducted with our robotic platform is reported, involving cannulation and balloon angioplasty of five target arteries.

RESULTS

The trials showed a 100% success rate, and post-mortem histopathological assessment demonstrated a reduction in the incidence and severity of vessel trauma with robotic navigation versus manual manipulation.

CONCLUSION

In-vivo experiments demonstrated that the applicability of our robotic system within the context of this study was well tolerated, with good feasibility, and low risk profile. Comparable results were observed with robotics and manual cannulation, with clinical outcome potentially in favor of robotics.

SIGNIFICANCE

This study showed that the proposed robotic platform can potentially improve the execution of endovascular procedures, paving the way for clinical translation.

Robotic endovascular surgery: current and future practice

Minimally invasive techniques have been at the forefront of surgical progress, and the evolution of endovascular robotic technologies has seen a paradigm shift in the focus of future innovation. Endovascular robotic technology may help overcome many of the challenges associated with traditional endovascular techniques by enabling greater control, stability, and precision of target navigation and treatment, while simultaneously reducing operator learning curves and improving safety. Several robotic systems have been developed to perform a broad range of endovascular procedures, but none have been used at scale or widely in routine practice, and the evidence for their safety, effectiveness, and efficiency remains limited. High cost and device complexity, lack of haptic feedback, and limited integration and interoperability with existing equipment and devices are the principal technology, cost, and sustainability barriers to the scalability and widespread adoption in day-to-day practice. In order to fully realize its potential, future robotic innovation must ensure compatibility with a range of off-the-shelf equipment that can be tracked and exchanged quickly during a procedure and come together with developments in navigation, tracking, and imaging. Reducing cost and complexity and supporting sustainability of the technology is key. In parallel, new technologies must be evaluated by clear and transparent standardized outcomes and be accompanied by robust clinical training. Key to the successful future development and dissemination of robotic technology is open collaboration among industry, clinicians, and patients in order to fully understand and address current challenges and enable the technology to realize its full potential.

An MR-Safe Endovascular Robotic Platform: Design, Control, and Ex-Vivo Evaluation

OBJECTIVE

Cardiovascular diseases are the most common cause of global death. Endovascular interventions, in combination with advanced imaging technologies, are promising approaches for minimally invasive diagnosis and therapy. More recently, teleoperated robotic platforms target improved manipulation accuracy, stabilisation of instruments in the vasculature, and reduction of patient recovery times. However, benefits of recent platforms are undermined by a lack of haptics and residual patient exposure to ionising radiation. The purpose of this research was to design, implement, and evaluate a novel endovascular robotic platform, which accommodates emerging non-ionising magnetic resonance imaging (MRI).

METHODS

We proposed a pneumatically actuated MR-safe teleoperation platform to manipulate endovascular instrumentation remotely and to provide operators with haptic feedback for endovascular tasks. The platform task performance was evaluated in an ex vivo cannulation study with clinical experts ( N = 7) under fluoroscopic guidance and haptic assistance on abdominal and thoracic phantoms.

RESULTS

The study demonstrated that the robotic dexterity involving pneumatic actuation concepts enabled successful remote cannulation of different vascular anatomies with success rates of 90%-100%. Compared to manual cannulation, slightly lower interaction forces between instrumentation and phantoms were measured for specific tasks. The maximum robotic interaction forces did not exceed 3N.

CONCLUSION

This research demonstrates a promising versatile robotic technology for remote manipulation of endovascular instrumentation in MR environments.

SIGNIFICANCE

The results pave the way for clinical translation with device deployment to endovascular interventions using non-ionising real-time 3D MR guidance.

Examining the impact of psychological distress on short-term postoperative outcomes after elective endovascular aneurysm repair (EVAR)

PURPOSE

Preoperative psychological factors have an impact on postoperative outcomes and there is a paucity of research in vascular surgery. The objective of this study was to examine the impact of preoperative psychological factors on short-term postoperative outcomes in an infrarenal endovascular aneurysm repair (EVAR) cohort.

METHODS

A prospective, multi-centre observational study was conducted across three vascular units in England. English-speaking participants who were older than 18 years, able to provide informed consent and awaiting an elective standard infrarenal EVAR were eligible for the study. A total of 46 patients undergoing elective infrarenal AAA repair were assessed preoperatively with the State Trait Anxiety Inventory (STAI), Beck's Depression Inventory (BDI-II) and Life Orientation Test-Revised (LOT-R). Data on five short-term postoperative outcomes was collected and analysed using Spearman's rank correlations.

RESULTS

Higher preoperative anxiety levels (ρ = 0.38, p = 0.01), and depression scores (ρ = 0.36, p = 0.02) were moderately correlated with an increased length of postoperative critical care stay. Higher levels of preoperative depression were moderately correlated with greater postoperative opioid analgesia use (ρ = 0.34, p = 0.02). No correlation was witnessed between optimism scores and postoperative outcomes. No correlation was witnessed with respect to total length of stay, number of complications, or time to mobilisation.

CONCLUSIONS

There is a potential link between preoperative psychological well-being and short-term postoperative outcomes in an EVAR cohort. Further work is necessary to validate this link and examine the role of preoperative interventions in optimising the psychological well-being of patients undergoing EVAR.

Robot-Assisted Carotid Artery Stenting: A Safety and Feasibility Study

PURPOSE

Endovascular robotics is an emerging technology within the developing field of medical robotics. This was a prospective evaluation to assess safety and feasibility of robotic-assisted carotid artery stenting.

MATERIALS AND METHODS

Consecutive cases of carotid artery stenting cases performed over period of 24 months, from May 2015 to October 2016, using the Magellan Robotic System (Hansen, Mountain View, CA) were included. All cases utilised the robotic system to navigate the arch, obtain a stable position in the common carotid artery, followed by manual manipulation of Embolic Protection Devices and self-expandable stents through the robotic catheter. Patients demographics, clinical indications, anatomical features, technical and clinical success, complication rate and hospital stay were prospectively recorded.

RESULTS

Thirteen patients, 10 males (78.5%), with an average age of 68.7 years were treated. Mean follow up time was 30 months. Ten patients (91%) were symptomatic at presentation. Anatomical indications for endovascular stent insertion were previous open surgery to the neck ± radiotherapy (87.5%) and hostile anatomy for open surgery (12.5%). Technical success was 100% and the robotic system demonstrates enhanced stability during arch and lesion crossing. There were no neurological complications post-operatively. Average hospital stay was 3 days (range 2-6 days) and a change in serum creatinine of -7.8 μmol/L. There was no documented case of in stent restenosis, new or worsening neurology during follow-up.

CONCLUSION

These results illustrate safety and feasibility of robotic endovascular revascularisation for carotid disease and demonstrates potential to enhance peri-procedural safety through improved control and stability.

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.

Using Fully-Immersive Simulation Training with Structured Debrief to Improve Nontechnical Skills in Emergency Endovascular Surgery

OBJECTIVE

Assess whether fully-immersive simulation training with structured debriefing of a standardized emergency thoracic endovascular aortic repair (TEVAR) scenario improves team-work performance of the lead surgeon. Secondary aims: assess whether technical skills (TS) and radiation safety behaviors (RSB) improved concurrently.

DESIGN

Pre-post study.

SETTING

UK-based training days.

PARTICIPANTS

General and vascular surgical trainees (n = 16).

INTERVENTION(S)

Fully-immersive simulation training with structured debriefing of a standardized emergency TEVAR scenario. Following standardized emergency TEVAR technical training, trainees led 2 standardized fully-immersive endovascular surgery simulations, with scripted support from a passive surgical team. A non-TS (NTS) structured debrief was delivered following simulations. NTS were assessed using the validated observational teamwork assessment for surgery tool post hoc using video recordings of simulations. TS were assessed through time taken to complete each step of the procedure, as defined during technical training. RSB were assessed through checking for presence of pre-defined actions and the length of time fluoroscopy was used during each simulation.

RESULTS

Total observational teamwork assessment for surgery scores improved following structured debrief (p = 0.005, median 52.55/90 vs 73.0/90), alongside all constituent domains - communication (p < 0.001, median 11.7/20 vs 16.6/20), coordination (p < 0.001, median 8.6/15 vs 13.4/15), cooperation (p < 0.001, median 13.15/20 vs 16.35/20), leadership (p < 0.001, median 8.70/15 vs 11.30/15) and monitoring (p < 0.001, median 9.85/20 vs 14.85/20). TS improved; time to complete 12 of 13 procedural steps improved (p < 0.027). Fluoroscopy time (seconds) decreased (p = 0.339, 543.6 vs 495.5), frequency lead surgeons checked the team were wearing leads increased (p = 0.125, 3 vs 7) and asked the team to step back before screening increased (p = 0.003, frequency team asked to step back/total angiography runs before = 2/36 vs after = 14/44).

CONCLUSIONS

fully-immersive endovascular simulation with structured debrief is a robust tool to improve NTS and TS. Incorporation into surgical training may reduce operating theatres errors, increase efficiency, and improve RSB. However effective translation into the clinical workplace must be demonstrated to see these benefits.

The Role of Wearable Technologies and Telemonitoring in Managing Vascular Disease

Wearable devices and telemonitoring are becoming increasingly widespread in the clinical environment and have many applications in the tracking and maintenance of patient wellbeing. Interventions incorporating these technologies have been used with some success in patients with vascular disorders. Wearable fitness monitors and telemonitoring have been used in the community to mobilise patients with peripheral vascular disease with good results. Additionally, wearable monitors and telemonitoring have been studied for blood pressure monitoring in patients with hypertension. Telemonitoring interventions incorporating electronic medication trays and ingestible sensors have also been found to increase drug adherence in hypertensive patients and ultimately improve health outcomes. However, wearable and telemonitoring interventions often face problems with patient adherence, digital literacy and infrastructure. Further work needs to address these challenges and validate the technology before widespread implementation can occur.

Avoidable 30-day readmissions in patients undergoing vascular surgery

BACKGROUND

Vascular surgery has one of the highest unplanned 30-day readmission rates of all surgical specialties. The degree to which these may be avoidable and the optimal strategies to reduce their occurrence are unknown. The aim of this study was to identify and classify avoidable 30-day readmissions in patients undergoing vascular surgery in order to plan targeted interventions to reduce their occurrence, improve outcomes and reduce cost.

METHODS

A retrospective analysis of discharges over a 12-month period from a single tertiary vascular unit was performed. A multidisciplinary panel conducted a manual case-note review to identify and classify those 30-day unplanned emergency readmissions deemed avoidable.

RESULTS

An unplanned 30-day readmission occurred in 72 of 885 admissions (8·1 per cent). These unplanned readmissions were deemed avoidable in 36 (50 per cent) of these 72 patients, and were most frequently due to unresolved medical issues (19 of 36, 53 per cent) and inappropriate admission with the potential for outpatient management (7 of 36, 19 per cent). A smaller number were due to inadequate social care provision (4 of 36, 11 per cent) and the occurrence of other avoidable adverse events (4 of 36, 11 per cent).

CONCLUSION

Half of all 30-day readmissions following vascular surgery are potentially avoidable. Multidisciplinary coordination of inpatient care and the transition from hospital to community care after discharge need to be improved.

An Evaluation of the Impact of High-Fidelity Endovascular Simulation on Surgeon Stress and Technical Performance

OBJECTIVE

To measure the physiological stress response associated with high-fidelity endovascular team simulation.

DESIGN

This is a prospective cohort study.

SETTING

This study was performed at St Mary's Hospital (Imperial College London, London, UK), in a tertiary setting.

PARTICIPANTS

Thirty-five participants (10 vascular surgical residents, 4 surgical interns, 12 theatre nurses, 2 attending vascular surgeons, 6 medical students and 1 technician) were recruited from the Imperial Vascular Unit at St Mary's Hospital, Imperial College London by direct approach. All participants finished the study.

RESULTS

Junior surgeons experienced significantly increased sympathetic tone (Low frequency/high frequency (LF/HF) ratio) during team simulation compared to individual simulation (6.01 ± 1.68 vs. 8.32 ± 2.84, p < 0.001). Within team simulation junior surgeons experienced significantly higher heart rate (beats per minute) than their senior counterparts (82 ± 5.83 vs. 76 ± 6.02, p = 0.033). Subjective workload scores (NASA Task Load Index [NASA-TLX]) correlated moderately and significantly with sympathetic tone in surgeons across all stages of simulation. (r = 0.39, p = 0.01).

CONCLUSIONS

A discrete, measurable increase in stress is experienced by surgeons during high-fidelity endovascular simulation and differentially effects junior surgeons. High-fidelity team simulation may have a role to play in improving nontechnical skill, reducing intra-operative stress, and reducing error.

Endovascular robotics

The current state and the future direction.

Learning-based endovascular navigation through the use of non-rigid registration for collaborative robotic catheterization

PURPOSE

Endovascular 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.

METHODS

Statistical 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.

RESULTS

The success rate for semiautomatic cannulation is 98.1% under dry simulation and 94.4% under continuous flow simulation. The proposed robotic approach achieved smoother catheter paths than manual approach. The mean contact forces have been reduced by 33.3% with the robotic approach, and 70.6% less STDEV forces were observed with the robot.

CONCLUSIONS

This work provides insights into catheter task planning and an improved design of hands-on ergonomic catheter navigation robots.

Two-Vessel Branched Stent Graft for Severely Angulated Aortic Arch Aneurysm in a Jehovah's Witness

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.

Flexible robotics in pelvic disease: does the catheter increase applicability of embolic therapy?

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.

The Impact of System Factors on Quality and Safety in Arterial Surgery: A Systematic Review

OBJECTIVE

A 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 SOURCES

A systematic review of original research papers in English using MEDLINE, Embase, PsycINFO, and Cochrane databases, was performed according to PRISMA guidelines.

REVIEW METHODS

Independent 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.

RESULTS

Twelve 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.

CONCLUSIONS

A 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 clinically relevant endpoints, and adherence to national reporting guidelines.

Objective Assessment of Endovascular Navigation Skills with Force Sensing

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.

Multicentre observational study of surgical system failures in aortic procedures and their effect on patient outcomes

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-working and equipment, and is associated with patient harm. Multidisciplinary team training, effective use of technology and new-device accreditation may improve patient outcomes.

Short- and Long-term Results of Hybrid Arch and Proximal Descending Thoracic Aortic Repair

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 technically feasible, with acceptable short-term mortality. There is a low rate of proximal landing zone reintervention when hybrid techniques are used to create an adequate proximal landing zone. Extra-anatomic bypass grafts have good long-term patency. Ongoing disease progression means that further distal aortic interventions are often necessary in patients with extensive disease.

Modified use of thoracic and iliac branch endografts to treat an abdominal aortic aneurysm with an unusually narrow neck

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.

Motion-adapted catheter navigation with real-time instantiation and improved visualisation

The improvements to catheter manipulation by the use of robot-assisted catheter navigation for endovascular procedures include increased precision, stability of motion and operator comfort. However, navigation through the vasculature under fluoroscopic guidance is still challenging, mostly due to physiological motion and when tortuous vessels are involved. In this paper, we propose a motion-adaptive catheter navigation scheme based on shape modelling to compensate for these dynamic effects, permitting predictive and dynamic navigations. This allows for timed manipulations synchronised with the vascular motion. The technical contribution of the paper includes the following two aspects. Firstly, a dynamic shape modelling and real-time instantiation scheme based on sparse data obtained intra-operatively is proposed for improved visualisation of the 3D vasculature during endovascular intervention. Secondly, a reconstructed frontal view from the catheter tip using the derived dynamic model is used as an interventional aid to user guidance. To demonstrate the practical value of the proposed framework, a simulated aortic branch cannulation procedure is used with detailed user validation to demonstrate the improvement in navigation quality and efficiency.

Segmental arterial mediolysis: a systematic review of 85 cases

BACKGROUND

Segmental arterial mediolysis (SAM) is a nonatherosclerotic, noninflammatory arteriopathy of unknown etiology with life-threatening manifestations. With advances in endovascular techniques, SAM is increasingly being managed without the need for major surgery.

METHODS

A systematic review of the literature published on SAM between 1976 and 2012 was performed, focusing on arterial involvement, diagnostic imaging modalities, mortality and morbidity rates, and in particular treatment outcomes with open versus endovascular intervention.

RESULTS

Sixty-two studies reporting on 85 cases of SAM were reviewed. Sixty-nine percent of cases were diagnosed histologically (24% on autopsy). Angiography was the most common form of diagnostic imaging modality (56% of cases). Arterial involvement was largely abdominal or cranial, with splenic arterial involvement being the most prevalent (29% of cases). There was a total SAM-related mortality of 26%. Endovascular intervention, most commonly in the form of coil embolization of aneurysmal vessel(s), was successful in 88% of cases where attempted, with no reported mortality. There was a mortality rate of 9% where open surgery was attempted.

CONCLUSIONS

Catheter-based endovascular techniques can be a successful, minimally invasive treatment option in the management of this potentially life-threatening condition, and may also provide a temporary bailout measure in the acute phase before definitive surgical treatment at a later stage.

Improved catheter navigation with 3D electromagnetic guidance

PURPOSE

To evaluate the in vitro performance of an electromagnetic navigation system (ENS) in aortic arch branch cannulation and describe its role for fenestrated endograft deployment.

METHODS

Reconstructed multidetector computed tomography images of silicone phantoms representing the aortic arch and a thoracoabdominal aortic aneurysm were uploaded onto the StealthStation workstation, which provided 3-dimensional visualization of a guidewire by tracking sensors on its tip. For the evaluation of aortic arch branch cannulation, 9 operators were asked to cannulate the phantom's common carotid and left subclavian arteries using the (1) ENS, (2) a 2-dimensional (2D) screen setting simulating fluoroscopy, and (3) both imaging modalities. Analysis included procedure times, number of wall hits, and the Imperial College Complex Cannulation Scoring Tool (IC3ST) qualitative performance score. To evaluate the ability of the ENS during positioning of a fenestrated stent-graft over the visceral segment, a custom-made 4-vessel fenestrated stent-graft with sensors on the fenestrations was deployed 5 consecutive times using the ENS as the exclusive imaging technique.

RESULTS

In the aortic arch model, cannulation times were significantly longer in the ENS group. However, compared with the 2D version, using both imaging modalities reduced fluoroscopic times [median 26.5 seconds (IQR 19.7-30.7) vs. 87 seconds (IQR 64-128), p<0.0001] and wall hits [median 8.5 (IQR 16-38) vs. 14 (IQR 11-160, p<0.05), while improving IC3ST performance scores [31/35 (IQR 30-31.2) vs. 25/35 (IQR 24-27), p<0.05]. Following deployment of the endograft with tracked fenestrations, the 4 visceral vessels were cannulated in all cases using only the ENS.

CONCLUSION

The use of the ENS as a complementary imaging modality might be beneficial in terms of radiation exposure, cannulation performance, and positioning of intravascular devices.

Index proposal and basic estimator study for quantification of oscillation of the secondary flow pattern in tortuous vessels

The development of atherosclerosis has been shown to correlate with regions of low wall shear stress and seemingly reduced mass transport. The local tortuosity of the arteries and local secondary flow oscillation also seem to be negatively correlated with the local occurrence of the disease. However there is currently no tool or physiological parameter that can be measured non-invasively to assess the local oscillation of the flow. Standard Colour Doppler imaging of secondary flow patterns during the blood pulse is studied and illustrated, and the local oscillation of the secondary flow pattern is proposed as an index, which could be an indicator of the likelihood of future disease development. Preliminary results are presented using a basic estimator developed for the proof of concept in the case of swirling flow, and based on colour-coded video signals collected in different configurations. In vitro results show that there is a correspondence between the Doppler patterns and the secondary flow patterns, the repeatability of the measures, and that the proposed index and its estimator reflect a joint influence of the local oscillation of the secondary flow pattern and of the flow rate. On another hand, while in vivo results still suffer from instabilities, noise and from scanners and processing limitations, they demonstrate that it is possible to use Colour Doppler imaging to image and characterize in vivo the secondary flow patterns and their oscillations non-invasively, and that it is possible for a trained clinician to perform manually such Doppler measurements for processing.

Robotically-steerable catheters and their role in the visceral aortic segment

In recent years, steerable catheter systems have been introduced into clinical practice for cardiac mapping and ablation procedures. As endovascular therapy is becoming more complex, more advanced and versatile catheter designs utilizing robotic technology may have a role in aortic and peripheral arterial interventions. This article discusses alternative steerable catheter designs focusing on robotic endovascular catheter technology. A comprehensive comparison, review and analysis of robotic versus manual techniques in the visceral segment are presented to reveal both their advantages and limitations. Preclinical studies and early experience suggest that robotically steerable endovascular catheters offer improved manoeuvrability at the catheter tip, enhanced positional control and "off-the-wall" centreline navigation in a remote-control fashion. These advanced systems have the potential to overcome some of the technical difficulties with manual catheter control, improve stability at key target areas, reduce the risk of vessel trauma, distal embolization and radiation exposure, whilst improving overall operator performance with short learning curves. Robotic catheter technology may be more suitable to complex and often unpredictable anatomy in the visceral segment and may offer a reliable platform for future applications involving device delivery or target intervention. This intuitive technology is rapidly evolving and still requires technological refinements to extend current capabilities. Clinical studies involving head-to-head comparisons with conventional techniques are essential for evaluating its long-term safety and efficacy.

Initial clinical application of a robotically steerable catheter system in endovascular aneurysm repair

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.