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Introduction: This was a European, multicenter, investigator-initiated and run, single-arm retrospective analysis to assess the safety and the clinical benefit of the use of paclitaxel-coated balloon (PCB) for the treatment of symptomatic central venous stenosis (CVS). Materials and Methods: Eleven centers from 7 countries across Europe, submitted 86 cases performed during the period between October 2015 and June 2018. Minimum follow-up was 6 months. Patient baseline demographics and procedural details were collected. Mean age was 62.6 years (SD 15.2 years). Median vascular access age was 3.0 years (IQR 1.2–4.8 years). A total of 55 were arteriovenous fistulas (64%) the rest arteriovenous grafts (31/86, 36%). Vessels treated were 43 subclavian veins, 42 brachiocephalic veins and 1 superior vena cava. Median drug-coated balloon diameter was 10 mm (IQR 8–12 mm). Primary outcome measures were clinically assessed intervention-free period (IFP) of the treated segment at 6 months and procedure-related minor and major complications. Secondary outcome measures included access circuit survival, patient survival, and the investigation of independent factors that influence the IFP. Results: IFP was 62.7% at 6 months. Median patient follow-up time was 1.0 year (IQR 0.5–2.2 years). There was 1 minor complication (1/86; 1.2%) and no major complications. Access circuit survival was 87.7% at 6 months. Patient survival was 79.7% at 2 years according to Kaplan-Meier survival analysis. Higher balloon diameters significantly favored IFP [HR 0.71 (0.55–0.92), p=0.006; 5–7 mm group vs 8–12 mm group, p=0.025]. Conclusion: In this analysis, use of PCBs for the treatment of symptomatic CVS was safe. Efficacy was comparable to previous trials. Increased balloon size had a significant effect on patency rates. © The Author(s) 2021.

Background: Foot perfusion has been recently implemented as a new tool for optimizing outcomes of peripheral endovascular procedures. A custom-made, two-dimensional perfusion digital subtraction angiography (PDSA) algorithm has been implemented to quantify outcomes of endovascular treatment of critical limb ischemia (CLI), assist intra-procedural decision-making, and enhance clinical outcomes. Methods: The study was approved by the Hospital’s Ethics Committee. This prospective, single-center study included seven consecutive patients scheduled to undergo infrapopliteal endovascular treatment of CLI. Perfusion blood volume (PBV), mean transit time (MTT), and perfusion blood flow (PBF) maps were extracted by analyzing time-intensity curves and signal intensity on the perfused vessel mask. Mean values calculated from user-specified regions of interest (ROIs) on perfusion maps were employed to evaluate pre- and post-endovascular treatment condition. Measurements were performed immediately after final PDSA. Results: In total, five patients (aged 54 ± 16 years, mean ± standard deviation) were analyzed, as two patients were excluded due to significant motion artifacts. Post-procedural MTT presented a mean decrease of 19.1% for all patients and increased only in 1 of 5 patients, demonstrating in 4/5 patients an increase in tissue perfusion after revascularization. Overall mean PBF and PBV values were also analogously increased following revascularization (446% and 69.5% mean, respectively) and in the majority of selected ROIs (13/15 and 12/15 ROIs, respectively). Conclusions: Quantification of infrapopliteal angioplasty outcomes using this newly proposed, custom-made, intra-procedural PDSA algorithm was performed using PBV, MTT, and PBF maps. Further studies are required to determine its role in peripheral endovascular procedures (ClinicalTrials.gov Identifier: NCT04356092). © 2020, The Author(s).

OBJECTIVE: The purpose of this study is to compare the safety and efficacy of the bedside ultrasound (US)-guided trocar technique versus the US- and fluoroscopy-guided Seldinger technique for percutaneous cholecystostomy (PC). SUBJECTS AND METHODS: This prospective noninferiority study compared the bedside US-guided trocar technique for PC (the trocar group; 53 patients [28 men and 25 women]; mean [± SD] age, 74.31 ± 16.19 years) with the US- and fluoroscopy-guided Seldinger technique for PC (the Seldinger group; 52 patients [26 men and 26 women], mean age, 79.92 ± 13.38 years) in consecutive patients undergoing PC at two large tertiary university hospitals. The primary endpoints were technical success and procedure-related complication rates. Secondary endpoints included procedural duration, pain assessment, and clinical success after up to 3 months of follow-up. RESULTS: PC was successfully performed for all 105 patients. The clinical success rate was similar between the two study groups (86.8% in the trocar group vs 76.9% in the Seldinger group; p = 0.09). Mean procedural time was significantly lower in the trocar group than in the Seldinger group (1.77 ± 1.62 vs 4.88 ± 2.68 min; p < 0.0001). Significantly more procedure-related complications were noted in the Seldinger group than in the trocar group (11.5% vs 1.9%; p = 0.02). Among patients in the Seldinger group, bile leak occurred in 7.7%, abscess formation in 1.9%, and gallbladder rupture in 1.9%. No procedure-related death was noted. Minor bleeding occurred in one patient (1.9%) in the trocar group, but the bleeding resolved on its own. The mean pain score during the procedure was significantly lower in the Seldinger group than in the trocar group (3.2 ± 1.77 vs 4.76 ± 2.17; p = 0.01). At 12 hours after the procedure, the mean pain score was significantly lower for patients in the trocar group (0.78 ± 1.0 vs 3.12 ± 1.36; p = 0.0001). CONCLUSION: Use of the bedside US-guided trocar technique for PC was equally effective as the Seldinger technique but was associated with fewer procedure-related complications, required less procedural time, and resulted in decreased postprocedural pain, compared with fluoroscopically guided PC using the Seldinger technique. © American Roentgen Ray Society.

Chronic liver disease (CLD) is currently one of the major causes of death worldwide. If not treated, it may lead to cirrhosis, hepatic carcinoma and death. Ultrasound (US) shear wave elastography (SWE) is a relatively new, popular, non-invasive technique among radiologists. Although many studies have been published validating the SWE technique either in a clinical setting, or by applying machine learning on SWE elastograms, minimal work has been done on comparing the performance of popular pre-trained deep learning networks on CLD assessment. Currently available literature reports suggest technical advancements on specific deep learning structures, with specific inputs and usually on a limited CLD fibrosis stage class group, with limited comparison on competitive deep learning schemes fed with different input types. The aim of the present study is to compare some popular deep learning pre-trained networks using temporally stable and full elastograms, with or without augmentation as well as propose suitable deep learning schemes for CLD diagnosis and progress assessment. 200 liver biopsy validated patients with CLD, underwent US SWE examination. Four images from the same liver area were saved to extract elastograms and processed to exclude areas that were temporally unstable. Then, full and temporally stable masked elastograms for each patient were separately fed into GoogLeNet, AlexNet, VGG16, ResNet50 and DenseNet201 with and without augmentation. The networks were tested for differentiation of CLD stages in seven classification schemes over 30 repetitions using liver biopsy as the reference. All networks achieved maximum mean accuracies ranging from 87.2%-97.4% and area under the receiver operating characteristic curves (AUCs) ranging from 0.979-0.990 while the radiologists had AUCs ranging from 0.800-0.870. ResNet50 and DenseNet201 had better average performance than the other networks. The use of the temporal stability mask led to improved performance on about 50% of inputs and network combinations while augmentation led to lower performance for all networks. These findings can provide potential networks with higher accuracy and better setting in the CLD diagnosis and progress assessment. A larger data set would help identify the best network and settings for CLD assessment in clinical practice. © 2020 Institute of Physics and Engineering in Medicine.

Background: We retrospectively investigated outcomes of emergency TAE for the management of life-threatening haemorrhage in patients with uncorrected bleeding diathesis. Materials and methods: This multicenter, retrospective, study, was designed to investigate the safety and efficacy of percutaneous TAE for the management of life-threatening haemorrhage in patients with uncorrected bleeding disorder at the time of embolization. All consecutive patients with uncorrected coagulation who underwent TAE for the treatment of haemorrhage, between January 1st and December 31th 2019 in three European centers were included. Inclusion criteria were thrombocytopenia (platelet count < 50,000/mL) and/or International Normalized Ratio (INR) ≥2.0, and/or activated partial thromboplastin time (aPTT) > 45 s, and/or a pre-existing underlying blood-clotting disorder such as factor VIII, Von Willebrand disease, hepatic cirrhosis with abnormal liver function tests. Primary outcome measures were technical success, rebleeding rate and clinical success. Secondary outcome measures included patients’ 30-day survival rate, and procedure-related complications. Results: In total, 134 patients underwent TAE for bleeding control. A subgroup of 17 patients with 18 procedures [11 female, mean age 70.5 ± 15 years] which represent 12.7% of the total number of patients, presented with pathological coagulation parameters at the time of TAE (haemophilia n = 3, thrombocytopenia n = 1, cirrhosis n = 5, anticoagulants n = 7, secondary to bleeding n = 1) and were analyzed. Technical success was 100%, as in all procedures the bleeding site was detected and successfully embolised. Clinical success was 100%, as none of the patients died of bleeding during hospitalization, nor was surgically treated for bleeding relapse. Only one rebleeding case was noted (5.9%) that was successfully treated with a second TAE. No procedure-related complications were noted. According to Kaplan-Meier analysis the estimated 30-day survival rate was 84.2%. Conclusion: TAE in selected patients with uncorrected bleeding diathesis should be considered as a suitable individualized management approach. Emergency TAE for life threatening haemorrhage in patients with coagulation cascade disorders should be used as an aid in realistic clinical decision making. © 2020, The Author(s).

Purpose: To automatically detect and isolate areas of low and high stiffness temporal stability in shear wave elastography (SWE) image sequences and define their impact in chronic liver disease (CLD) diagnosis improvement by means of clinical examination study and deep learning algorithm employing convolutional neural networks (CNNs). Materials and Methods: Two hundred SWE image sequences from 88 healthy individuals (F0 fibrosis stage) and 112 CLD patients (46 with mild fibrosis (F1), 16 with significant fibrosis (F2), 22 with severe fibrosis (F3), and 28 with cirrhosis (F4)) were analyzed to detect temporal stiffness stability between frames. An inverse Red, Green, Blue (RGB) colormap-to-stiffness process was performed for each image sequence, followed by a wavelet transform and fuzzy c-means clustering algorithm. This resulted in a binary mask depicting areas of high and low stiffness temporal stability. The mask was then applied to the first image of the SWE sequence, and the derived, masked SWE image was used to estimate its impact in standard clinical examination and CNN classification. Regarding the impact of the masked SWE image in clinical examination, one measurement by two radiologists was performed in each SWE image and two in the corresponding masked image measuring areas with high and low stiffness temporal stability. Then, stiffness stability parameters, interobserver variability evaluation and diagnostic performance by means of ROC analysis were assessed. The masked and unmasked sets of SWE images were fed into a CNN scheme for comparison. Results: The clinical impact evaluation study showed that the masked SWE images decreased the interobserver variability of the radiologists’ measurements in the high stiffness temporal stability areas (interclass correlation coefficient (ICC) = 0.92) compared to the corresponding unmasked ones (ICC = 0.76). In terms of diagnostic accuracy, measurements in the high-stability areas of the masked SWE images (area-under-the-curve (AUC) ranging from 0.800 to 0.851) performed similarly to those in the unmasked SWE images (AUC ranging from 0.805 to 0.893). Regarding the measurements in the low stiffness temporal stability areas of the masked SWE images, results for interobserver variability (ICC = 0.63) and diagnostic accuracy (AUC ranging from 0.622 to 0.791) were poor. Regarding the CNN classification, the masked SWE images showed improved accuracy (ranging from 82.5% to 95.5%) compared to the unmasked ones (ranging from 79.5% to 93.2%) for various CLD stage combinations. Conclusion: Our detection algorithm excludes unreliable areas in SWE images, reduces interobserver variability, and augments CNN's accuracy scores for many combinations of fibrosis stages. © 2019 American Association of Physicists in Medicine

Surgical partial nephrectomy is still considered as the “gold standard” for the definitive management of small malignant renal masses, whereas treatment with image-guided percutaneous ablation is still mainly reserved for those patients who cannot undergo nephron-sparing surgical resection due to advanced age, underlying comorbidities or compromised renal function. Nonetheless, the recent evidence that underlines the long-term oncological equipoise of percutaneous ablation methods with surgical resection in combination with the reduced complication rate and cost supports the use of an image-guided minimally invasive approach as a first-line treatment. The purpose of this review is to offer an overview of the most widely used percutaneous renal ablation treatments (radiofrequency, microwave and cryoablation) with a focus on their main technical aspects and application techniques for curative ablation of small renal cell carcinoma (stage cT1a). The authors also provide a critical narrative of the relevant medical literature with an emphasis on outcomes of comparative effectiveness research, and appraise the percutaneous methods compared to surgery in the context of evidence-based practice and future research studies. Teaching Points: • RCC is a common cancer and is increasingly detected incidentally at early stages. • There is long-term oncological equipoise of percutaneous ablation compared to surgical resection. • Large-scale trials are required to produce Level 1a evidence. © 2018, The Author(s).

Purpose: To report the incidence and long-term outcomes following endovascular treatment of symptomatic, atherosclerotic isolated popliteal artery disease (IPAD). Materials and Methods: This retrospective, multicenter study included all patients who underwent endovascular treatment of IPAD between January 2010 and December 2016 because of intermittent claudication or critical limb ischemia (CLI), in three tertiary University Hospitals. In total, 4717 peripheral arterial disease (PAD) procedures were analyzed. The study’s primary outcome measures were: IPAD incidence, binary restenosis rate and freedom from target lesion revascularization (TLR). Secondary outcome measures included technical success, limb salvage rate and the identification of predictors of outcomes. Results: The incidence of IPAD was 0.98% (46/4717 PAD procedures). In total, 46 patients (38 male; mean age 73 ± 12 years) underwent plain balloon (69.5%) or bail-out stenting (30.5%) procedures. Most patients suffered from CLI (65.2%). Mean lesion length was 52.5 ± 32.0 mm and 45.6% of the cases were occlusions. Severe calcifications were noted in 26.1%. Technical success was 100%. Mean time follow-up was 32.6 ± 25.6 months. According to Kaplan–Meier analysis, restenosis was 15.8, 40.9, 45.8% and TLR-free rate was 90.5, 79.0, 74.1%, at 1, 2 and 3 years, respectively. Survival and limb salvage rates were 73.6 and 88.1%, at 5 years, respectively. The major amputation rate for CLI patients was 10.0% (3/29 limbs), while no major amputations occurred in the claudication subgroup. Cox multivariable analysis detected baseline occlusion as an independent predictor of increased restenosis (HR 5.3; 95% CI 0.21–0.66, p = 0.02). Conclusions: Isolated popliteal lesions requiring treatment appear in nearly 1% of patients with PAD. Balloon angioplasty and bail-out stenting resulted in acceptable long-term clinical outcomes. Treatment of occlusions was correlated with increased restenosis rate. © 2018, Springer Science+Business Media, LLC, part of Springer Nature and the Cardiovascular and Interventional Radiological Society of Europe (CIRSE).

Introduction: Thrombosis is the most important access-related complication. Several declotting procedures have been suggested falling mainly into two categories; thrombolysis-dependent and thrombectomy-dependent. Areas covered: Seventeen studies after 2001 have been published on percutaneous treatment of thrombosed vascular access. Authors performed a systematic review of these studies together with a parametric meta-analysis of data available investigating clinical success, postintervention assisted primary patency (PAPP) and independent factors that could influence outcome measures. Expert commentary: A shift to thrombectomy-dependent procedures is observed with a view to diminishing complications from the use of thrombolytic agents. Arteriovenous fistulas provide significantly better PAPP, while newer studies show improved, non-significant results compared with older ones. The role of improvement of devices for subsequent angioplasty is of equal importance, if not more, for improved declotting results. © 2018 Informa UK Limited, trading as Taylor & Francis Group.

The purpose of the present study was to employ a computer-aided diagnosis system that classifies chronic liver disease (CLD) using ultrasound shear wave elastography (SWE) imaging, with a stiffness value-clustering and machine-learning algorithm. A clinical data set of 126 patients (56 healthy controls, 70 with CLD) was analyzed. First, an RGB-to-stiffness inverse mapping technique was employed. A five-cluster segmentation was then performed associating corresponding different-color regions with certain stiffness value ranges acquired from the SWE manufacturer-provided color bar. Subsequently, 35 features (7 for each cluster), indicative of physical characteristics existing within the SWE image, were extracted. A stepwise regression analysis toward feature reduction was used to derive a reduced feature subset that was fed into the support vector machine classification algorithm to classify CLD from healthy cases. The highest accuracy in classification of healthy to CLD subject discrimination from the support vector machine model was 87.3% with sensitivity and specificity values of 93.5% and 81.2%, respectively. Receiver operating characteristic curve analysis gave an area under the curve value of 0.87 (confidence interval: 0.77–0.92). A machine-learning algorithm that quantifies color information in terms of stiffness values from SWE images and discriminates CLD from healthy cases is introduced. New objective parameters and criteria for CLD diagnosis employing SWE images provided by the present study can be considered an important step toward color-based interpretation, and could assist radiologists’ diagnostic performance on a daily basis after being installed in a PC and employed retrospectively, immediately after the examination. © 2017 World Federation for Ultrasound in Medicine & Biology

Traditional percutaneous balloon angioplasty and stent placement is based on mechanical plaque disruption and displacement within the arterial wall. On the contrary, transcatheter atherectomy achieves atherosclerotic plaque clearance by means of directional plaque excision or rotational plaque removal or laser plaque ablation. Debulking atherectomy may allow for a more uniform angioplasty result at lower pressures with consequently less vessel barotrauma and improved luminal gain, thereby decreasing the risk of plaque recoil and dissection that may require permanent metal stenting. It has been also argued that atherectomy may disrupt the calcium barrier and optimize drug transfer and delivery in case of drug-coated balloon applications. The authors discuss the various types of atherectomy devices available in clinical practice to date and critically appraise their mode of action as well as relevant published data in each case. Overall, amassed randomized and observational evidence indicates that percutaneous atherectomy of the femoropopliteal and infrapopliteal arteries may achieve high technical success rates and seems to lessen the frequency of bailout stenting, however, at the expense of increased risk of peri-procedural distal embolization. Long-term clinical outcomes reported to date do not support the superiority of percutaneous atherectomy over traditional balloon angioplasty and stent placement in terms of vessel patency or limb salvage. The combination of debulking atherectomy and drug-coated balloons has shown promise in early studies, especially in the treatment of more complex lesions. Unanswered questions and future perspectives of this continuously evolving endovascular technology as part of a broader treatment algorithm are discussed. © 2017, The Author(s).

Purpose: To automatically segment and classify focal liver lesions (FLLs) on nonenhanced T2-weighted magnetic resonance imaging (MRI) scans using a computer-aided diagnosis (CAD) algorithm. Methods: 71 FLLs (30 benign lesions, 19 hepatocellular carcinomas, and 22 metastases) on T2-weighted MRI scans were delineated by the proposed CAD scheme. The FLL segmentation procedure involved wavelet multiscale analysis to extract accurate edge information and mean intensity values for consecutive edges computed using horizontal and vertical analysis that were fed into the subsequent fuzzy C-means algorithm for final FLL border extraction. Texture information for each extracted lesion was derived using 42 first- and second-order textural features from grayscale value histogram, co-occurrence, and run-length matrices. Twelve morphological features were also extracted to capture any shape differentiation between classes. Feature selection was performed with stepwise multilinear regression analysis that led to a reduced feature subset. A multiclass Probabilistic Neural Network (PNN) classifier was then designed and used for lesion classification. PNN model evaluation was performed using the leave-one-out (LOO) method and receiver operating characteristic (ROC) curve analysis. Results: The mean overlap between the automatically segmented FLLs and the manual segmentations performed by radiologists was 0.91 ± 0.12. The highest classification accuracies in the PNN model for the benign, hepatocellular carcinoma, and metastatic FLLs were 94.1%, 91.4%, and 94.1%, respectively, with sensitivity/specificity values of 90%/97.3%, 89.5%/92.2%, and 90.9%/95.6% respectively. The overall classification accuracy for the proposed system was 90.1%. Conclusions: Our diagnostic system using sophisticated FLL segmentation and classification algorithms is a powerful tool for routine clinical MRI-based liver evaluation and can be a supplement to contrast-enhanced MRI to prevent unnecessary invasive procedures. © 2017 American Association of Physicists in Medicine.

Background: Pharmacotherapy is of increasing interest in peripheral arterial disease (PAD), with novel therapies aiming at different factors contributing to the disease. For antiplatelet therapy, there is no unanimous agreement regarding the nature or duration of optimal antiplatelet therapy so as to reduce major adverse cardiovascular and limb-related events (e.g. repeat interventions and amputations). However, evidence on novel more potent antithrombotic agents, drug combinations and personalized antiplatelet therapy for PAD patients is accumulating. Similarly, statins are now considered as a standard of care in PAD patients, due to their multiple actions which include plaque stabilization, antiinflammatory properties and regression of atheroma. Conclusion: This review focuses on current evidence available for various antiplatelet regimens and statin therapy for PAD and discusses future perspectives. We consider randomized controlled trials, together with the most important reviews and meta-analyses. Treatment algorithms based on currently available data. © 2017 Bentham Science Publishers.

Amassed evidence from several randomized controlled trials and high quality meta-analyses clearly support the primary use of paclitaxel-coated balloons (PCB) in the superficial femoral artery over traditional plain balloon angioplasty or primary bare nitinol stenting with significantly lower vascular restenosis, less need for repeat procedures, improved quality of life and potential cost savings for the healthcare system. Stents may be reserved for bail-out in case of a suboptimal dilatation result, and for selected more complex lesions, or in case of critical limb ischemia in order to eliminate vessel recoil and maximize immediate hemodynamic gain. Debulking atherectomy remains unproven, but holds a lot of promise in particular in combination with PCBs, in order to improve compliance of the vessel wall by plaque removal, allow for a better angioplasty result and optimize drug transfer and bioavailability. The present overview summarizes and discusses current evidence about femoropopliteal PCB angioplasty compared to the historical standard of plain old balloon angioplasty and bare nitinol stents. Available evidence is appraised in the context of clinically meaningful results, relevant unresolved issues are highlighted, and future trends are discussed.

Purpose: To report a Bayesian network meta-analysis of randomized controlled trials (RCTs) comparing bare metal stents (BMS), paclitaxel-coated balloons (PCBs), and drug-eluting stents (DES) with balloon angioplasty (BA) or with each other in the infrapopliteal arteries. Methods: Sixteen RCTs comprising 1805 patients with 1-year median follow-up were analyzed. Bayesian random effects binomial models were employed (WinBUGS). Relative treatment effects were expressed as odds ratios (ORs) with 95% credible intervals (CrI), and the cumulative rank probabilities were calculated to provide hierarchies of competing treatments. Quality of evidence (QoE) was assessed with the GRADE (grading of recommendations assessment, development, and evaluation) system. Sensitivity, heterogeneity, and consistency analyses were performed. Results: There was high QoE that infrapopliteal DES significantly reduced restenosis compared with BMS (OR 0.26, 95% CrI 0.12 to 0.51) and BA (OR 0.22, 95% CrI 0.11 to 0.45). Likewise, DES significantly reduced target lesion revascularization (TLR) compared with BA (OR 0.41, 95% CrI 0.22 to 0.75) and BMS (OR 0.26, 95% CrI 0.15 to 0.45). Paclitaxel-coated balloons also reduced TLR compared with BA (OR 0.55, 95% CrI 0.34 to 0.90) and BMS (OR 0.35, 95% CrI 0.18 to 0.67), but QoE was low to moderate. BA had lower TLR than BMS (OR 0.63, 95% CrI 0.40 to 0.99) with high QoE. DES was the only treatment that significantly reduced limb amputations compared with BA (OR 0.58, 95% CrI 0.35 to 0.96), PCB (OR 0.51, 95% CrI 0.26 to 0.98), or BMS (OR 0.38, 95% CrI 0.19 to 0.72) with moderate to high QoE. DES also significantly improved wound healing compared with BA (OR 2.02, 95% CrI 1.01 to 4.07) or BMS (OR 3.45, 95% CrI 1.41 to 8.73) with high QoE. Results were stable on sensitivity and meta-regression analyses without any significant publication bias or inconsistency. Conclusion: Infrapopliteal DES were associated with significantly lower rates of restenosis, TLR, and amputations and improved wound healing compared to BA and BMS. DES also significantly reduced amputations compared with PCB. © The Author(s) 2016.

Introduction: Percutaneous transcatheter balloon angioplasty has evolved to the current mainstay treatment for salvage of dysfunctional dialysis access. Nonetheless, it is frequently associated with recurrent vessel restenosis and the need for multiple repeat treatments in order to maintain hemodynamic patency. Cutting-balloons, covered stents or stent-grafts, and paclitaxel-coated balloons have been extensively tested and investigated with the aim to improve immediate anatomical and long-term clinical results. Areas covered: In the present overview, we discuss the background and appraise relevant medical literature on the aforementioned technologies and provide a more in-depth synthesis of the results of different clinical studies for each device category. We will also discuss the limitations in the mode of action of each group of devices and envision what the future holds for the challenging field of dialysis access interventions. Expert commentary: We propose a good practice algorithm for the treatment of thrombosed or dysfunctional dialysis access. © 2016 Informa UK Limited, trading as Taylor & Francis Group.

Purpose: Classify chronic liver disease (CLD) from ultrasound shear-wave elastography (SWE) imaging by means of a computer aided diagnosis (CAD) system. Methods: The proposed algorithm employs an inverse mapping technique (red-green-blue to stiffness) to quantify 85 SWE images (54 healthy and 31 with CLD). Texture analysis is then applied involving the automatic calculation of 330 first and second order textural features from every transformed stiffness value map to determine functional features that characterize liver elasticity and describe liver condition for all available stages. Consequently, a stepwise regression analysis feature selection procedure is utilized toward a reduced feature subset that is fed into the support vector machines (SVMs) classification algorithm in the design of the CAD system. Results: With regard to the mapping procedure accuracy, the stiffness map values had an average difference of 0.01?0.001 kPa compared to the quantification results derived from the color-box provided by the built-in software of the ultrasound system. Highest classification accuracy from the SVM model was 87.0% with sensitivity and specificity values of 83.3% and 89.1%, respectively. Receiver operating characteristic curves analysis gave an area under the curve value of 0.85 with [0.770.89] confidence interval. Conclusions: The proposed CAD system employing color to stiffness mapping and classification algorithms offered superior results, comparing the already published clinical studies. It could prove to be of value to physicians improving the diagnostic accuracy of CLD and can be employed as a second opinion tool for avoiding unnecessary invasive procedures. © 2016 Am. Assoc. Phys. Med.

Hypertension has been rarely reported in patients with the nutcracker phenomenon/syndrome. We describe a young male adult where a computed tomography angiography provided evidence of left renal vein dilatation, probably due to its compression through the angle between the aorta and the superior mesenteric artery, during the evaluation for secondary hypertension. As there were no other signs for secondary hypertension, we proceeded with a venography of the inferior vena cava and the renal veins that revealed mild anatomical findings compatible with the so called nutcracker phenomenon/syndrome. Blood levels of renin and aldosterone and renocaval pressure gradient from these sites were between normal limits. As there were coexisting anatomical and clinical findings (hypertension), nutcracker syndrome might have been claimed. However, no causal links could be established and these findings should be considered only as a coincidence.

Purpose: To report the safety and efficacy of percutaneous nephrostomy and primary antegrade recanalization for treatment of iatrogenic ureteral strictures after gynecologic surgery. Patients and Methods: Ten women had symptoms suggestive of ureteral obstruction during the immediate postoperative period (5 days-1 week after surgery). Under analgesia and conscious sedation, standard percutaneous nephrostomy was performed, and a long 7F sheath was placed in the upper ureter. The obstructions were traversed with the aid of a 0.0035-inch Glidewire and a 5F angled Glide catheter (Terumo, Japan). Subsequently, the areas were dilated with angioplasty balloons to a maximum diameter of 7 mm. Finally, an 8F percutaneous internal/external nephroureteral drainage stent was inserted to secure ureteral patency. Follow-up was carried out by serial nephrostomography until removal of the stent and by renal ultrasonography thereafter. Results: Twelve obstructions with a mean length of 1.4 cm (range 0.4-1.9 cm) were managed. The technical success rate was 100%. No major complications occurred, and normal renal function was restored. The mean follow-up was 12 months. In 60% of the patients, a patent ureter was depicted at 1 week, whereas in four patients, repeat dilation of the obstructed segment was required. The stents were removed after a mean period of 4.8 weeks. Conclusion: Percutaneous nephrostomy and primary antegrade ureteral balloon dilation is safe and efficacious for treating ureteral injury after pelvic surgery and obviates open surgical manipulations.