Predictors of bleeding complications during catHeter-dirEcted thrombolysis for peripheral arterial occlusions (POCHET).

INTRODUCTION: The risk of major bleeding complications in catheter directed thrombolysis (CDT) for acute limb ischemia (ALI) remains high, with reported major bleeding complication rates in up to 1 in every 10 treated patients. Fibrinogen was the only predictive marker used for bleeding complications in CDT, despite the lack of high quality evidence to support this. Therefore, recent international guidelines recommend against the use of fibrinogen during CDT. However, no alternative biomarkers exist to effectively predict CDT-related bleeding complications. The aim of the POCHET biobank is to prospectively assess the rate and etiology of bleeding complications during CDT and to provide a biobank of blood samples to investigate potential novel biomarkers to predict bleeding complications during CDT. METHODS: The POCHET biobank is a multicentre prospective biobank. After informed consent, all consecutive patients with lower extremity ALI eligible for CDT are included. All patients are treated according to a predefined standard operating procedure which is aligned in all participating centres. Baseline and follow-up data are collected. Prior to CDT and subsequently every six hours, venous blood samples are obtained and stored in the biobank for future analyses. The primary outcome is the occurrence of non-access related major bleeding complications, which is assessed by an independent adjudication committee. Secondary outcomes are non-major bleeding complications and other CDT related complications. Proposed biomarkers to be investigated include fibrinogen, to end the debate on its usefulness, anti-plasmin and D-Dimer. DISCUSSION AND CONCLUSION: The POCHET biobank provides contemporary data and outcomes of patients during CDT for ALI, coupled with their blood samples taken prior and during CDT. Thereby, the POCHET biobank is a real world monitor on biomarkers during CDT, supporting a broad spectrum of future research for the identification of patients at high risk for bleeding complications during CDT and to identify new biomarkers to enhance safety in CDT treatment.

Hepatic Arteriography and C-Arm CT-Guided Ablation (HepACAGA) to Improve Tumor Visualization, Navigation and Margin Confirmation in Percutaneous Liver Tumor Ablation.

PURPOSE: We present a technique that combines Hepatic Arteriography with C-arm CT-Guided Ablation (HepACAGA) to improve tumor visualization, navigation and margin confirmation for percutaneous ablation of liver tumors. MATERIALS AND METHODS: All consecutive patients scheduled for HepACAGA between April 20th, 2021, and November 2nd, 2021, were included in this retrospective, cohort study. HepACAGA was performed in an angiography-suite under general anesthesia. The hepatic artery was catheterized for selective contrast injection. C-arm CT and guidance software were then used to visualize the tumor and the microwave antenna was inserted during apnea. Pre- and post-ablation C-arm CTs were performed and ablation margins assessed. Technical success, antenna placement deviation, number of repositions, tumor recurrence, and safety were evaluated. Technical success was defined as a tumor that was ablated according to the HepACAGA technique. RESULTS: A total of 21 patients (28 tumors) were included. The main tumor type was colorectal cancer liver metastases (11/21, 52%), followed by hepatocellular carcinoma (7/21, 33%), neuroendocrine tumor metastases (1/21, 5%), and other tumor types (2/21, 10%). The technical success rate was 93% (26/28 tumors) with two small hypovascular lesions unable to be identified. A single microwave antenna was used in all patients. The median antenna placement deviation was 1 mm (range 0-6 mm). At a median follow-up time of 16 months (range 5-22 months), there was no tumor recurrence in any patient. Safety analysis showed a complication rate of 5% grade 2 and 5% grade 3. CONCLUSION: HepACAGA was demonstrated to be a safe and effective percutaneous ablation technique, without any local tumor recurrence in this study.

Systematic Review on Botulinum Toxin Injections as Diagnostic or Therapeutic Tool in Thoracic Outlet Syndrome.

BACKGROUND: The optimal diagnostic and treatment algorithm for patients with suspected thoracic outlet syndrome (TOS) remains challenging. Botulinum toxin (BTX) muscle injections have been suggested to shrink muscles in the thoracic outlet reducing neurovascular compression. This systematic review evaluates the diagnostic and therapeutic value of BTX injections in TOS. METHODS: A systematic review of studies reporting BTX as a diagnostic or therapeutic tool in TOS (or pectoralis minor syndrome as TOS subtype) was conducted in PubMed, Embase, and CENTRAL databases on May 26, 2022. The Preferred Reporting Items for Systematic Reviews and Meta-Analyses statement was followed. Primary end point was symptom reduction after primary procedure. Secondary end points were symptom reduction after repeated procedures, the degree of symptom reduction, complications, and duration of clinical effect. RESULTS: Eight studies (1 randomized controlled trial [RCT], 1 prospective cohort study, and 6 retrospective cohort studies) were included reporting 716 procedures in at least 497 patients (at minimum 350 primary and 25 repeated procedures, residual unclear) diagnosed with presumably only neurogenic TOS. Except for the RCT, the methodological quality was fair to poor. All studies were designed on an intention to treat basis, one also investigated BTX as a diagnostic tool to differentiate pectoralis minor syndrome from costoclavicular compression. Reduction of symptoms was reported in 46-63% of primary procedures; no significant difference was found in the RCT. The effect of repeated procedures could not be determined. Degree of symptom reduction was reported by up to 30-42% on the Short-form McGill Pain scale and up to 40 mm on a visual analog scale. Complication rates varied among studies, no major complications were reported. Symptom relief ranged from 1 to 6 months. CONCLUSIONS: Based on limited quality evidence, BTX may provide short-lasting symptom relief in some neurogenic TOS patients but remains overall undecided. The role of BTX for treatment of vascular TOS and as a diagnostic tool in TOS is currently unexploited.

Thoracic outlet syndrome (TROTS) registry: A study protocol for the primary upper extremity deep venous thrombosis section.

INTRODUCTION: There is a lack of comprehensive and uniform data on primary upper extremity deep venous thrombosis (pUEDVT). pUEDVT includes venous thoracic outlet syndrome related upper extremity deep venous thrombosis (UEDVT) and idiopathic UEDVT. Research on these conditions has been hampered by their rarity, lack of uniform diagnostic criteria, and heterogeneity in therapeutic strategies. To improve current research data collection using input of all various pUEDVT treating medical specialists, we initiated the ThoRacic OuTlet Syndrome (TROTS) registry. The aim of the TROTS registry is to a) collect extensive data on all pUEDVT patients through a predefined protocol, b) give insight in the long term outcome using patient reported outcome measures, c) create guidance in the diagnostic and clinical management of these conditions, and thereby d) help provide content for future research. METHODS AND ANALYSIS: The TROTS registry was designed as an international prospective longitudinal observational registry for data collection on pUEDVT patients. All pUEDVT patients, regardless of treatment received, can be included in the registry after informed consent is obtained. All relevant data regarding the initial presentation, diagnostics, treatment, and follow-up will be collected prospectively in an electronic case report form. In addition, a survey containing general questions, a Health-related Quality of Life questionnaire (EQ-5D-5L), and Functional Disability questionnaire (Quick-DASH) will be sent periodically (at the time of inclusion, one and two years after inclusion, and every five years after inclusion) to the participant. The registry protocol was approved by the Medical Ethical Review Board and registered in the Netherlands Trial Register under Trial-ID NL9680. The data generated by the registry will be used for future research on pUEDVT and published in peer reviewed journals. CONCLUSION: TROTS registry data will be used to further establish the optimal management of pUEDVT and lay the foundation for future research and guidelines.

Multicenter Case Series and Literature Review on Durability of Stents in the Thoracic Outlet.

PURPOSE: The aim of this paper was to report our experience with arterial and venous endovascular stent placement in the thoracic outlet (TO) and review available literature. METHODS: All patients that underwent arterial or venous stent placement in the TO between 2013 and 2020 in 5 Dutch vascular teaching-hospitals were retrospectively identified. Primary endpoint was symptomatic stent failure due to stenosis, chronic or posture dependent compression, fracture, or occlusion of the stent. Secondary endpoints were symptoms at last follow-up and re-interventions. For the literature review, we searched studies reporting on stenting in the TO. RESULTS: Twenty-six patients were included with 11 arterial and 15 venous stents implanted to treat angioplasty resistant stenosis in arterial or venous TO syndrome, iatrogenic or traumatic vascular injury, radiotherapy fibrosis, or arterial dissection. Median follow-up was 19 and 14 months in the arterial and venous-group, respectively. Eight (73%) patients in the arterial, and 9 (60%) in the venous-group suffered symptomatic stent failure. Seven (64%) patients in the arterial, and 9 (60%) in the venous-group required at least 1 re-intervention. When comparing all patients with stent placement after TO decompression (TOD) to patients without, there were substantially more symptomatic stent failures and re-interventions required in the patients without TOD. Six patients (54%) in the arterial-group and 11 (73%) in the venous-group were symptom-free at last follow-up. Five articles describing 51 patients with arterial and 6 articles describing 81 patients with venous stents were included in the literature review. In the arterial-group, no TOD prior to stent placement was performed, while in the venous-group all but 1 article performed TOD prior to stent placement. Results showed comparable rates of symptomatic stent failure (24% vs 30%), and patients requiring re-interventions (29% vs 21%) between groups. CONCLUSION: Based on our multicenter series and review, stents in the TO have a considerable risk of failure, both in the venous and the arterial territory. Especially in patients without TOD: the need for re-interventions is high and half the patients eventually undergo TOD. Based on the currently available data, stenting in the TO should be applied cautiously while TOD should be considered.

The profile of cognitive impairment and hemodynamic compromise in moyamoya: a single-center prospective cohort study.

OBJECTIVE: Patients with moyamoya vasculopathy often experience cognitive impairments. In this prospective single-center study, the authors investigated the profile of neurocognitive impairment and its relation with the severity of ischemic brain lesions and hemodynamic compromise. METHODS: Patients treated in a Dutch tertiary referral center were prospectively included. All patients underwent standardized neuropsychological evaluation, MRI, digital subtraction angiography, and [15O]H2O-PET (to measure cerebrovascular reactivity [CVR]). The authors determined z-scores for 7 cognitive domains and the proportion of patients with cognitive impairment (z-score < -1.5 SD in at least one domain). The authors explored associations between patient characteristics, imaging and CVR findings, and cognitive scores per domain by using multivariable linear regression and Bayesian regression analysis. RESULTS: A total of 40 patients (22 children; 75% females) were included. The median age for children was 9 years (range 1-16 years); for adults it was 39 years (range 19-53 years). Thirty patients (75%) had an infarction, and 31 patients (78%) had impaired CVR (steal phenomenon). Six of 7 cognitive domains scored below the population norm. Twenty-nine patients (73%) had cognitive impairment. Adults performed better than children in the cognitive domain visuospatial functioning (p = 0.033, Bayes factor = 4.0), and children performed better in processing speed (p = 0.041, Bayes factor = 3.5). The authors did not find an association between infarction, white matter disease, or CVR and cognitive domains. CONCLUSIONS: In this Western cohort, cognitive functioning in patients with moyamoya vasculopathy was below the population norm, and 73% had cognitive impairment in at least one domain. The cognitive profile differed between adults and children. The authors could not find an association with imaging findings.

Synthetic MRI with Magnetic Resonance Spin TomogrAphy in Time-Domain (MR-STAT): Results from a Prospective Cross-Sectional Clinical Trial.

BACKGROUND: Magnetic Resonance Spin TomogrAphy in Time-domain (MR-STAT) can reconstruct whole-brain multi-parametric quantitative maps (eg, T1 , T2 ) from a 5-minute MR acquisition. These quantitative maps can be leveraged for synthetization of clinical image contrasts. PURPOSE: The objective was to assess image quality and overall diagnostic accuracy of synthetic MR-STAT contrasts compared to conventional contrast-weighted images. STUDY TYPE: Prospective cross-sectional clinical trial. POPULATION: Fifty participants with a median age of 45 years (range: 21-79 years) consisting of 10 healthy participants and 40 patients with neurological diseases (brain tumor, epilepsy, multiple sclerosis or stroke). FIELD STRENGTH/SEQUENCE: 3T/Conventional contrast-weighted imaging (T1 /T2 weighted, proton density [PD] weighted, and fluid-attenuated inversion recovery [FLAIR]) and a MR-STAT acquisition (2D Cartesian spoiled gradient echo with varying flip angle preceded by a non-selective inversion pulse). ASSESSMENT: Quantitative T1 , T2 , and PD maps were computed from the MR-STAT acquisition, from which synthetic contrasts were generated. Three neuroradiologists blinded for image type and disease randomly and independently evaluated synthetic and conventional datasets for image quality and diagnostic accuracy, which was assessed by comparison with the clinically confirmed diagnosis. STATISTICAL TESTS: Image quality and consequent acceptability for diagnostic use was assessed with a McNemar's test (one-sided α = 0.025). Wilcoxon signed rank test with a one-sided α = 0.025 and a margin of Δ = 0.5 on the 5-level Likert scale was used to assess non-inferiority. RESULTS: All data sets were similar in acceptability for diagnostic use (≥3 Likert-scale) between techniques (T1 w:P = 0.105, PDw:P = 1.000, FLAIR:P = 0.564). However, only the synthetic MR-STAT T2 weighted images were significantly non-inferior to their conventional counterpart; all other synthetic datasets were inferior (T1 w:P = 0.260, PDw:P = 1.000, FLAIR:P = 1.000). Moreover, true positive/negative rates were similar between techniques (conventional: 88%, MR-STAT: 84%). DATA CONCLUSION: MR-STAT is a quantitative technique that may provide radiologists with clinically useful synthetic contrast images within substantially reduced scan time. EVIDENCE LEVEL: 1 Technical Efficacy: Stage 2.

Clinical Outcome, Cognition, and Cerebrovascular Reactivity after Surgical Treatment for Moyamoya Vasculopathy: A Dutch Prospective, Single-Center Cohort Study.

Background: It remains unclear whether revascularization of moyamoya vasculopathy (MMV) has a positive effect on cognitive function. In this prospective, single-center study, we investigated the effect of revascularization on cognitive function in patients with MMV. We report clinical and radiological outcome parameters and the associations between clinical determinants and change in neurocognitive functioning. Methods: We consecutively included all MMV patients at a Dutch tertiary referral hospital who underwent pre- and postoperative standardized neuropsychological evaluation, [15O]H2O-PET (including cerebrovascular reactivity (CVR)), MRI, cerebral angiography, and completed standardized questionnaires on clinical outcome and quality of life (QOL). To explore the association between patient characteristics, imaging findings, and change in the z-scores of the cognitive domains, we used multivariable linear- and Bayesian regression analysis. Results: We included 40 patients of whom 35 (27 females, 21 children) were treated surgically. One patient died after surgery, and two withdrew from the study. TIA- and headache frequency and modified Rankin scale (mRS) improved (resp. p = 0.001, 0.019, 0.039). Eleven patients (seven children) developed a new infarct during follow-up (31%), five of which were symptomatic. CVR-scores improved significantly (p < 0.0005). The language domain improved (p = 0.029); other domains remained stable. In adults, there was an improvement in QOL. We could not find an association between change in imaging and cognitive scores. Conclusion: In this cohort of Western MMV patients, TIA frequency, headache, CVR, and mRS improved significantly after revascularization. The language domain significantly improved, while others remained stable. We could not find an association between changes in CVR and cognitive scores.

A Uremic Pig Model for Peritoneal Dialysis.

With increasing interest in home dialysis, there is a need for a translational uremic large animal model to evaluate technical innovations in peritoneal dialysis (PD). To this end, we developed a porcine model with kidney failure. Stable chronic kidney injury was induced by bilateral subtotal renal artery embolization. Before applying PD, temporary aggravation of uremia was induced by administration of gentamicin (10 mg/kg i.v. twice daily for 7 days), to obtain uremic solute levels within the range of those of dialysis patients. Peritoneal transport was assessed using a standard peritoneal permeability assessment (SPA). After embolization, urea and creatinine concentrations transiently increased from 1.6 ± 0.3 to 7.5 ± 1.2 mM and from 103 ± 14 to 338 ± 67 µM, respectively, followed by stabilization within 1-2 weeks to 2.5 ± 1.1 mM and 174 ± 28 µM, respectively. Gentamicin induced temporary acute-on-chronic kidney injury with peak urea and creatinine concentrations of 16.7 ± 5.3 mM and 932 ± 470 µM respectively. PD was successfully applied, although frequently complicated by peritonitis. SPA showed a low transport status (D/P creatinine at 4 h of 0.41 (0.36-0.53)) with a mass transfer area coefficient of 9.6 ± 3.1, 4.6 ± 2.6, 3.4 ± 2.3 mL/min for urea, creatinine, and phosphate respectively. In conclusion, this porcine model with on-demand aggravation of uremia is suitable for PD albeit with peritoneal transport characterized by a low transport status.

Synthetic CT for the planning of MR-HIFU treatment of bone metastases in pelvic and femoral bones: a feasibility study.

OBJECTIVES: Visualization of the bone distribution is an important prerequisite for MRI-guided high-intensity focused ultrasound (MRI-HIFU) treatment planning of bone metastases. In this context, we evaluated MRI-based synthetic CT (sCT) imaging for the visualization of cortical bone. METHODS: MR and CT images of nine patients with pelvic and femoral metastases were retrospectively analyzed in this study. The metastatic lesions were osteolytic, osteoblastic or mixed. sCT were generated from pre-treatment or treatment MR images using a UNet-like neural network. sCT was qualitatively and quantitatively compared to CT in the bone (pelvis or femur) containing the metastasis and in a region of interest placed on the metastasis itself, through mean absolute difference (MAD), mean difference (MD), Dice similarity coefficient (DSC), and root mean square surface distance (RMSD). RESULTS: The dataset consisted of 3 osteolytic, 4 osteoblastic and 2 mixed metastases. For most patients, the general morphology of the bone was well represented in the sCT images and osteolytic, osteoblastic and mixed lesions could be discriminated. Despite an average timespan between MR and CT acquisitions of 61 days, in bone, the average (± standard deviation) MAD was 116 ± 26 HU, MD - 14 ± 66 HU, DSC 0.85 ± 0.05, and RMSD 2.05 ± 0.48 mm and, in the lesion, MAD was 132 ± 62 HU, MD - 31 ± 106 HU, DSC 0.75 ± 0.2, and RMSD 2.73 ± 2.28 mm. CONCLUSIONS: Synthetic CT images adequately depicted the cancellous and cortical bone distribution in the different lesion types, which shows its potential for MRI-HIFU treatment planning. KEY POINTS: • Synthetic computed tomography was able to depict bone distribution in metastatic lesions. • Synthetic computed tomography images intrinsically aligned with treatment MR images may have the potential to facilitate MR-HIFU treatment planning of bone metastases, by combining visualization of soft tissues and cancellous and cortical bone.

Intraarterial Administration Boosts 177Lu-HA-DOTATATE Accumulation in Salvage Meningioma Patients.

Intravenous 177Lu-high-affinity (HA)-DOTATATE has shown promising results for the treatment of surgery- and radiotherapy-refractory meningiomas. We aimed to investigate the added value of intraarterial administration. Methods: Patients underwent at least 1 intravenous 177Lu-HA-DOTATATE treatment first and subsequent intraarterial cycles. Inpatient and intrapatient comparison was based on posttreatment 177Lu-HA-DOTATATE imaging 24 h after injection. The technical success rate and adverse events were recorded. Results: Four patients provided informed consent. The technical success rate was 100%, and no angiography-related or unexpected adverse events occurred. Intrapatient comparison showed an increased target lesion accumulation on both planar imaging (mean, +220%) and SPECT/CT (mean, +398%) after intraarterial administration, compared with intravenous administration. No unexpected adverse events occurred during follow-up. Conclusion: Intraarterial peptide receptor radionuclide therapy significantly increases tracer accumulation and is a safe and promising improvement for salvage meningioma patients. Future prospective studies on intraarterial peptide receptor radionuclide therapy are needed to determine the gain in efficacy and survival.

The Global Limb Anatomic Staging System (GLASS) for CLTI: Improving Inter-Observer Agreement.

OBJECTIVE: The 2020 Global Vascular Guidelines aim at improving decision making in Chronic Limb-Threatening Ischemia (CLTI) by providing a framework for evidence-based revascularization. Herein, the Global Limb Anatomic Staging System (GLASS) serves to estimate the chance of success and patency of arterial pathway revascularization based on the extent and distribution of the atherosclerotic lesions. We report the preliminary feasibility results and observer variability of the GLASS. GLASS is a part of the new global guideline and posed as a promising additional tool for EBR strategies to predict the success of lower extremity arterial revascularization. This study reports on the consistency of GLASS scoring to maximize inter-observer agreement and facilitate its application. METHODS: GLASS separately scores the femoropopliteal (FP) and infrapopliteal (IP) segment based on stenosis severity, lesion length and the extent of calcification within the target artery pathway (TAP). In our stepwise approach, we used two angiographic datasets. Each following step was based on the lessons learned from the previous step. The primary outcome was inter-observer agreement measured as Cohen's Kappa, scored by two (step 1 + 2) and four (step 3) blinded and experienced observers, respectively. Steps 1 (n = 139) and 2 (n = 50) were executed within a dataset of a Dutch interventional RCT in CLTI. Step 3 (n = 100) was performed in randomly selected all-comer CLTI patients from two vascular centers in the United States. RESULTS: In step 1, kappa values were 0.346 (FP) and 0.180 (IP). In step 2, applied in the same dataset, the use of other experienced observers and a provided TAP, resulted in similar low kappa values 0.406 (FP) and 0.089 (IP). Subsequently, in step 3, the formation of an altered stepwise approach using component scoring, such as separate scoring of calcification and adding a ruler to the images resulted in kappa values increasing to 0.796 (FP) and 0.730 (IP). CONCLUSION: This retrospective GLASS validation study revealed low inter-observer agreement for unconditioned scoring. A stepwise component scoring provides acceptable agreement and a solid base for further prospective validation studies to investigate how GLASS relates to treatment outcomes.

A Uremic Goat Model Created by Subtotal Renal Artery Embolization and Gentamicin.

A large animal model of (end-stage) kidney disease (ESKD) is needed for the preclinical testing of novel renal replacement therapies. This study aimed to create stable uremia via subtotal renal artery embolization in goats and induce a temporary further decline in kidney function by administration of gentamicin. Renal artery embolization was performed in five Dutch white goats by infusing polyvinyl alcohol particles in branches of the renal artery, aiming for the embolization of ~80% of one kidney and complete embolization of the contralateral kidney. Gentamicin was administered to temporarily further increase the plasma concentrations of uremic toxins. After initial acute kidney injury, urea and creatinine plasma concentrations stabilized 1.5 ± 0.7 months post-embolization and remained elevated (12 ± 1.4 vs. 5.6 ± 0.8 mmol/L and 174 ± 45 vs. 65 ± 5.6 µmol/L, resp.) during follow-up (16 ± 6 months). Gentamicin induced temporary acute-on-chronic kidney injury with a variable increase in plasma concentrations of small solutes (urea 29 ± 15 mmol/L, creatinine 841 ± 584 µmol/L, phosphate 2.2 ± 0.3 mmol/L and potassium 5.0 ± 0.6 mmol/L) and protein-bound uremic toxins representative of patients with ESKD. A uremic goat model characterized by stable moderate uremia was established via subtotal renal artery embolization with the induction of temporary severe acute-on-chronic kidney injury by the administration of gentamicin, allowing preclinical in vivo validation of novel renal replacement technologies.

First in Human Clinical Feasibility Study of Endovascular Navigation with Fiber Optic RealShape (FORS) Technology.

OBJECTIVE: Endovascular procedures are conventionally conducted using two dimensional fluoroscopy. A new technology platform, Fiber Optic RealShape (FORS), has recently been introduced allowing real time, three dimensional visualisation of endovascular devices using fiberoptic technology. It functions as an add on to conventional fluoroscopy and may facilitate endovascular procedures. This first in human study assessed the feasibility of FORS in clinical practice. METHODS: A prospective cohort feasibility study was performed between July and December 2018. Patients undergoing (regular or complex) endovascular aortic repair (EVAR) or endovascular peripheral lesion repair (EVPLR) were recruited. FORS guidance was used exclusively during navigational tasks such as target vessel catheterisation or crossing of stenotic lesions. Three types of FORS enabled devices were available: a flexible guidewire, a Cobra-2 catheter, and a Berenstein catheter. Devices were chosen at the physician's discretion and could comprise any combination of FORS and non-FORS devices. The primary study endpoint was technical success of the navigational tasks using FORS enabled devices. Secondary study endpoints were user experience and fluoroscopy time. RESULTS: The study enrolled 22 patients: 14 EVAR and eight EVPLR patients. Owing to a technical issue during start up, the FORS system could not be used in one EVAR. The remaining 21 procedures proceeded without device or technology related complications and involved 66 navigational tasks. In 60 tasks (90.9%), technical success was achieved using at least one FORS enabled device. Users rated FORS based image guidance "better than standard guidance" in 16 of 21 and "equal to standard guidance" in five of 21 procedures. Fluoroscopy time ranged from 0.0 to 52.2 min. Several tasks were completed without or with only minimal X-ray use. CONCLUSION: Real time navigation using FORS technology is safe and feasible in abdominal and peripheral endovascular procedures. FORS has the potential to improve intra-operative image guidance. Comparative studies are needed to assess these benefits and potential radiation reduction.

Three Dimensional Visualisation of Endovascular Guidewires and Catheters Based on Laser Light instead of Fluoroscopy with Fiber Optic RealShape Technology: Preclinical Results.

OBJECTIVE: Fiber Optic RealShape (FORS) is a new technology platform that enables real time three dimensional (3D) visualisation of endovascular guidewires and catheters, based on the concepts of fibre optic technology instead of fluoroscopy. Anatomical context is provided by means of co-registered prior anatomical imaging, such as digital subtraction angiography or computed tomography. This preclinical study assesses the safety and feasibility of FORS technology. METHODS: Six physicians performed endovascular tasks in a phantom model and a porcine model using FORS enabled floppy guidewires, Cobra-2 catheters and Berenstein catheters. Each physician performed a set of predefined tasks in both models, including setup of the FORS system, device registration, and 12 aortic and peripheral target vessel cannulation tasks. The evaluation of the FORS system was based on (i) target vessel cannulation success; (ii) safety assessment; (iii) the accuracy of the FORS based device visualisation; and (iv) user experience. RESULTS: Successful cannulation was achieved in 72 of the 72 tasks (100%) in the phantom model and in 70 of the 72 tasks (97%) in the porcine model. No safety issues were reported. The FORS based device visualisation had a median offset at the tip of 2.2 mm (interquartile range 1.2-3.8 mm). The users judged the FORS based device visualisation to be superior to conventional fluoroscopic imaging, while not affecting the mechanical properties (torquability, pushability) of the FORS enabled guidewire and catheters. CONCLUSION: The combined outcomes of high cannulation success, positive user experience, adequate accuracy, and absence of safety issues demonstrate the safety and feasibility of the FORS system in a preclinical environment. FORS technology has great potential to improve device visualisation in endovascular interventions.