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.

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.

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.

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.

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.

Heterogeneity in Standard Operating Procedures for Catheter Directed Thrombolysis for Peripheral Arterial Occlusions in The Netherlands: A Nationwide Overview.

OBJECTIVE: Catheter directed thrombolysis (CDT) for acute arterial occlusions of the lower extremities is associated with a risk of major bleeding complications. Strict monitoring of vital functions is advised for timely adjustment or discontinuation of thrombolytic treatment. Nevertheless, current evidence on the optimal application of CDT and use of monitoring during CDT is limited. In this study the different standard operating procedures (SOPs) for CDT in Dutch hospitals were compared against a national guideline in a nationwide analysis. METHODS: SOPs, landmark studies, and national and international guidelines for CDT for acute lower extremity arterial occlusions were compared. The protocols of 34 Dutch medical centres where CDT is performed were assessed. Parameters included contraindications to CDT, co-administration of heparin, thrombolytic agent administration, angiographic control, and patient monitoring. RESULTS: Thirty-four SOPs were included, covering 94% of medical centres performing CDT in the Netherlands. None of the SOPs had identical contraindications and a strong divergence in relative and absolute grading was found. Heparin and urokinase dosages differed by a factor of five. In 18% of the SOPs heparin co-administration was not mentioned. Angiographic control varied between once every 6 h to once every 24 h. In 76% of the SOPs plasma fibrinogen levels were used for CDT dose adjustments. However, plasma fibrinogen level threshold values for treatment adjustments varied between 2.0 g/L and 0.5 g/L. CONCLUSION: The SOPs for CDT for acute arterial occlusions of the lower extremities differ greatly on five major operating aspects among medical centres in the Netherlands. None of the SOPs exactly conforms to current national or international guidelines. This study provides direction on how to increase homogeneity in guideline recommendations and to improve guideline adherence in CDT.

Catheter-based renal denervation as therapy for chronic severe kidney-related pain.

Background: Loin pain haematuria syndrome (LPHS) and autosomal dominant polycystic kidney disease (ADPKD) are the most important non-urological conditions to cause chronic severe kidney-related pain. Multidisciplinary programmes and surgical methods have shown inconsistent results with respect to pain reduction. Percutaneous catheter-based renal denervation (RDN) could be a less invasive treatment option for these patients. Methods: Our aim was to explore the change in perceived pain and use of analgesic medication from baseline to 3, 6 and 12 months after RDN. Patients with LPHS or ADPKD, who experienced kidney-related pain ≥3 months with a visual analogue scale (VAS) score ≥ 50/100 could be included. Percutaneous RDN was performed with a single-electrode radiofrequency ablation catheter. Results: RDN was performed in 11 patients (6 with LPHS and 5 with ADPKD). Perceived pain declined in the whole group by 23 mm (P = 0.012 for the total group). In patients with LPHS and ADPKD, the median daily defined dosage of analgesic medication decreased from 1.6 [interquartile range (IQR) 0.7-2.3] and 1.4 (IQR 0.0-7.4) at baseline to 0.3 (IQR 0.0-1.9; P = 0.138) and 0.0 (IQR 0.0-0.8; P = 0.285) at 12 months, respectively. Mean estimated glomerular filtration rate decreased in the whole group by 5.4 mL/min/1.73 m2 at 6 months compared with baseline (P = 0.163). Conclusions: These results suggest that percutaneous catheter-based RDN reduces pain complaints and the use of analgesic medication in patients with LPHS or ADPKD. The present results can serve as the rationale for a larger, preferably randomized (sham) controlled study.

Six uneventful pregnancy outcomes in an extended vascular Ehlers-Danlos syndrome family.

Vascular Ehlers-Danlos Syndrome (vEDS) is caused by heterozygous mutations in COL3A1 and is characterized by fragile vasculature and hollow organs, with a high risk of catastrophic events at a young age. During pregnancy and delivery, maternal mortality rates up until 25% have been reported. However, recent pedigree analysis reported a substantial lower pregnancy-related mortality rate of 4.9%. Here, we describe an extended vEDS family with multiple uneventful pregnancy outcomes. In the proband, a 37-year-old woman, DNA-analysis because of an asymptomatic iliac artery dissection revealed a pathogenic mutation in COL3A1 (c.980G>A; p. Gly327Asp). She had had three uneventful vaginal deliveries. At the time of diagnosis, her 33-year-old niece was 25 weeks pregnant. She had had one uneventful vaginal delivery. Targeted DNA-analysis revealed that she was carrier of the COL3A1 mutation. Ultrasound detected an aneurysm in the abdominal aorta with likely a dissection. An uneventful elective cesarean section was performed at a gestational age of 37 weeks. The 40-year-old sister of our proband had had one uneventful vaginal delivery and an active pregnancy wish. Cascade DNA-screening showed her to carry the COL3A1 mutation. Computed Tomography Angiography (CTA) of her aorta revealed a type B dissection with the most proximal entry tear just below the superior mesenteric artery. Pregnancy was therefore discouraged. This familial case illustrates the complexity and challenges of reproductive decision-making in a potentially lethal condition as vEDS, and highlights the importance of a multidisciplinary approach. Moreover, it suggests that previous pregnancy-related risks of vEDS may be overestimated. © 2016 Wiley Periodicals, Inc.

Renal artery and parenchymal changes after renal denervation: assessment by magnetic resonance angiography.

OBJECTIVES: Relatively little is known about the incidence of long-term renal damage after renal denervation (RDN), a potential new treatment for hypertension. In this study the incidence of renal artery and parenchymal changes, assessed with contrast-enhanced magnetic resonance angiography (MRA) after RDN, is investigated. METHODS: This study is an initiative of ENCOReD, a collaboration of hypertension expert centres. Patients in whom an MRA was performed before and after RDN were included. Scans were evaluated by two independent, blinded radiologists. Primary outcome was the change in renal artery morphology and parenchyma. RESULTS: MRAs from 96 patients were analysed. Before RDN, 41 renal anomalies were observed, of which 29 mostly mild renal artery stenoses. After a median time of 366 days post RDN, MRA showed a new stenosis (25-49% lumen reduction) in two patients and progression of pre-existing lumen reduction in a single patient. No other renal changes were observed and renal function remained stable. CONCLUSIONS: We observed new or progressed renal artery stenosis in three out of 96 patients, after a median time of 12 months post RDN (3.1%). Procedural angiographies showed that ablations were applied near the observed stenosis in only one of the three patients. KEY POINTS: • The incidence of vascular changes 12 months post RDN was 3.1%. • No renal vascular or parenchymal changes other than stenoses were observed. • Ablations were applied near the stenosis in only one of three patients.

Automatic Localization of Cochlear Implant Electrode Contacts in CT.

OBJECTIVES: Determining the exact location of cochlear implant (CI) electrode contacts after implantation is important, as it helps quantifying the relation between CI positioning and hearing outcome. Unfortunately, localization of individual contacts can be difficult, because the spacing between the electrode contacts is near the spatial resolution limit of high-resolution clinical computed tomography (CT) scanners. This study introduces and examines a simple, automatic method for the localization of intracochlear electrode contacts. CI geometric specifications may provide the prior knowledge that is essential to accurately estimate contact positions, even though individual contacts may not be visibly resolved. DESIGN: The prior knowledge in CI geometry is used to accurately estimate intracochlear electrode contact positions in high-resolution CT scans of seven adult patients implanted with a CI (Cochlear Ltd.). The automatically detected electrode contact locations were verified against locations marked by two experienced observers. The interobserver errors and the errors between the averaged locations and the automatically detected locations were calculated. The estimated contact positions were transformed to a cylindrical cochlear coordinate system, according to an international consensus, in which the insertion angles and the radius and elevation were measured. RESULTS: The linear correlation of the automatically detected electrode contact positions with the manually detected locations was high (R = 0.98 for the radius, and R = 1.00 for the insertion angle). The errors in radius and in insertion angle between the automatically detected locations and the manually detected locations were 0.12 mm and 1.7°. These errors were comparable to the interobserver errors. Geometrical measurements were in line with what is usually found in human cochleae. The mean insertion angle of the most apical electrode was 410° (range: 316° to 503°). The mean radius of the electrode contacts in the first turn of the cochlear spiral was 3.0 mm, and the mean radius of the remainder in the second turn was 1.7 mm. CONCLUSIONS: With implant geometry as prior knowledge, automatic analysis of high-resolution CT scans enables accurate localization of CI electrode contacts. The output of this method can be used to study the effect of CI positioning on hearing outcomes in more detail.

Modest utility of quantitative measures in (18)F-fluorodeoxyglucose positron emission tomography scanning for the diagnosis of aortic prosthetic graft infection.

BACKGROUND: The clinical dilemma in suspected aortic graft infection (AGI) is how to noninvasively obtain a reliable proof of infection. In addition to confirming the presence of infection, obtaining information regarding the extent of infection to select a proper strategy for reoperation is also necessary. Therefore, developing a more reliable noninvasive physiologic approach to detect infected prostheses is required. (18)F-fluorodeoxyglucose positron emission tomography scanning ((18)F-FDG PET) has been suggested to have a pivotal role in the detection of AGI. In this study, we assessed the contribution of two (semi) quantitative parameters-maximal standardized uptake value (SUVmax) and tissue-to-background ratio (TBR)-and of two visual parameters-fluorodeoxyglucose (FDG) distribution patterns and visual grading scale-in the final confirmation of the diagnosis of AGI. METHODS: Patients with a central aortic prosthetic graft and symptoms clinically suggestive of AGI were gathered from a prospectively maintained database. Included were those who underwent (18)F-FDG PET scanning combined with computed tomography angiography and in whom periprosthetic samples were taken at some stage in the diagnostic process. AGI was considered proven in case of a positive culture and compared with a group with negative cultures. Positive predictive values (PPVs) and negative predictive values (NPVs) were calculated. Receiver operating characteristics curves were used to assess the ability of SUVmax and TBR to identify the presence and absence of AGI (ie, accuracy). RESULTS: In 37 of 77 patients with suspected AGI, (18)FDG-PET and perigraft material for culturing was obtained. The tissue culture was positive in 21 of these 37 patients (56.7%). Mean ± standard deviation SUVmax for proven infection was 8.1 ± 3.7 (range, 3.6-18.5) and TBR was 5.9 ± 2.7 (range, 1.7-13.0). The area under the curve for SUVmax was 0.78 (95% confidence interval, 0.63-0.93). A cutoff value of 8 yielded a PPV of 80% and a NPV of 54%. The area under the curve for TBR was 0.70 (95% confidence interval, 0.52-0.87). A cutoff value of 6 yielded a PPV of 73% and NPV of 52%. The PPVs for the visual grading scale and (18)F-FDG distribution patterns were 75% and 61%, respectively; the NPVs were 77% and 67%, respectively. CONCLUSIONS: Our study, performed in a small sample of patients suspected of AGI, showed that the diagnostic abilities of quantitative and visual (18)F-FDG PET parameters are modest.

Through-Plane Movement at Multiple Aortic Levels on Dynamic Computed Tomography Angiography Is Limited in Patients With an Abdominal Aortic Aneurysm.

PURPOSE: To analyze the movement of the aorta in the craniocaudal direction (through-plane movement) during the cardiac cycle at several levels to determine any potential impact on endovascular aneurysm repair (EVAR) of abdominal aortic aneurysm (AAA). METHODS: For this study, 30 patients (median age 73.0 years; 27 men) with an infrarenal AAA were randomly selected from a prospectively maintained EVAR database. All patients had undergone preoperative electrocardiogram-gated computed tomography angiography consisting of 8 phases. After semiautomatic segmentation, a 3-dimensional location probe was placed in the center of the aorta (center point) on the orthogonal slices at 12 different levels along the aorta and iliac arteries for all 8 phases. Movement of the center point during the cardiac cycle was analyzed for each level. Values are given as the median and interquartile range (IQR). RESULTS: The median through-plane movement of all levels was 3.0 mm (IQR 2.8-3.2) and appeared to be lower in the region of the celiac and renal arteries: 2.6 mm (IQR 1.7-3.1) at 3 cm proximal to the most distal renal artery and 2.4 mm (IQR 1.9-2.9) at 1 cm distal to the most distal renal artery, respectively. The thoracic part of the aorta showed the largest through-plane motion: 4.1 mm (IQR 2.7-4.6). CONCLUSION: This study quantifies aortic through-plane motion in the craniocaudal direction. Since through-plane movement appears to be limited, findings of previous studies investigating pulsatile in-plane distension seem to be representative for aortic distension.

The effect of renal denervation added to standard pharmacologic treatment versus standard pharmacologic treatment alone in patients with resistant hypertension: rationale and design of the SYMPATHY trial.

The first studies on renal denervation (RDN) suggest that this treatment is feasible, effective, and safe in the short term. Presently available data are promising, but important uncertainties exist; therefore, SYMPATHY has been initiated. SYMPATHY is a multicenter, randomized, controlled trial in patients randomized to RDN in addition to usual care (intervention group) or to continued usual care (control group). Randomization will take place in a ratio of 2 to 1. At least 300 participants will be included to answer the primary objective. Sample size may be extended to a maximum of 570 to address key secondary objectives. The primary objective is to assess whether RDN added to usual care compared with usual care alone reduces blood pressure (BP) (ambulatory daytime systolic BP) in subjects with an average daytime systolic BP ≥135, despite use of ≥3 BP-lowering agents, 6 months after RDN. Key secondary objectives are evaluated at 6 months and at regular intervals during continued follow-up and include the effect of RDN on the use of BP-lowering agents, in different subgroups (across strata of estimated glomerular filtration rate and of baseline BP), on office BP, quality of life, and cost-effectiveness.

Renal denervation in multiple renal arteries.

BACKGROUND: In most previous studies investigating efficacy of renal denervation (RDN), patients with multiple renal arteries are generally excluded from treatment. This study was designed to determine the prevalence of multiple renal arteries in patients referred for RDN, to propose a classification for anatomical eligibility and to investigate the relation between the presence of multiple arteries and blood pressure (BP)-lowering effect. MATERIALS AND METHODS: Patients referred for RDN who underwent noninvasive imaging of the renal arteries before treatment were included in present analysis. Eligible patients were treated. Renal function and BP were evaluated 6 months after treatment. RESULTS: Hundred and twenty-six patients referred for RDN were included in present analysis. Thirty-four per cent had multiple arteries. Sixty-nine patients underwent RDN. Office BP significantly reduced from 195 (± 26)/106 (± 14) mmHg to 165 (± 24)/95 (± 14) mmHg (P < 0·001). BP reduction in patients with multiple arteries which were all treated was comparable to patients with solitary arteries. However, patients with multiple which were not all treated showed a trend towards a less pronounced effect of RDN (ß: 11·6, P = 0·11). The proposed classification appeared useful by identifying eligible anatomy. Renal function at 6 months did not differ from baseline in all subgroups. CONCLUSIONS: Based on our results and the high prevalence of multiple arteries, it seems reasonable not to exclude patients with multiple renal arteries from RDN. Current analysis suggests that BP reduction may be less pronounced in patients with multiple renal arteries of whom not all arteries were treated.