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Background The known risks and benefits of native kidney biopsies are mainly based on the findings of retrospective studies. The aim of this multicentre prospective study was to evaluate the safety of percutaneous renal biopsies and quantify biopsy-related complication rates in Italy. Methods The study examined the results of native kidney biopsies performed in 54 Italian nephrology centres between 2012 and 2020. The primary outcome was the rate of major complications 1 day after the procedure, or for longer if it was necessary to evaluate the evolution of a complication. Centre and patient risk predictors were analysed using multivariate logistic regression. Results Analysis of 5304 biopsies of patients with a median age of 53.2 years revealed 400 major complication events in 273 patients (5.1%): the most frequent was a ≥2 g/dL decrease in haemoglobin levels (2.2%), followed by macrohaematuria (1.2%), blood transfusion (1.1%), gross haematoma (0.9%), artero-venous fistula (0.7%), invasive intervention (0.5%), pain (0.5%), symptomatic hypotension (0.3%), a rapid increase in serum creatinine levels (0.1%) and death (0.02%). The risk factors for major complications were higher plasma creatinine levels [odds ratio (OR) 1.12 for each mg/dL increase, 95% confidence interval (95% CI) 1.08–1.17], liver disease (OR 2.27, 95% CI 1.21–4.25) and a higher number of needle passes (OR for each pass 1.22, 95% CI 1.07–1.39), whereas higher proteinuria levels (OR for each g/day increase 0.95, 95% CI 0.92–0.99) were protective. Conclusions This is the first multicentre prospective study showing that percutaneous native kidney biopsies are associated with a 5% risk of a major post-biopsy complication. Predictors of increased risk include higher plasma creatinine levels, liver disease and a higher number of needle passes.

Background Glucagon-like peptide-1 receptor agonists (GLP-1RAs) are highly effective in improving glycaemic control either as monotherapy or in combination with other hypoglycaemic drugs, and have low incidence of side effects, such as hypoglycaemia, nausea and weight gain, thus increasing patients' adherence to therapy. Methods In this review we report the most recent studies demonstrating the beneficial effects of GLP-1RAs on renal outcomes, and also discuss the direct and indirect mechanisms through which they confer kidney protection. Finally, we discuss the metabolic and anti-inflammatory effects of GLP-1RAs in diabetic patients with COVID-19 disease. Results GLP-1RAs have a nephroprotective action, which is expressed through both indirect (improvement of blood pressure and glycaemic control, weight loss) and direct (restoration of normal intrarenal haemodynamics, prevention of ischaemic and oxidative damage) effects. They have shown also metabolic and anti-inflammation beneficial effects in patients with COVID-19 disease. Conclusions GLP-1RAs prevent albuminuria and slow the decline of renal function towards end stage renal disease in patients with diabetic kidney disease. They might be an opportunity to break the typical inflammation processes of COVID-19 disease.

Chronic kidney disease is characterized by increasingly amplified fibrotic processes regardless of etiology. The severity of renal fibrosis seems to correlate with an increased risk of end-stage renal disease; therefore, monitoring of renal fibrosis over time may play an important role in the follow-up of both focal and diffuse renal diseases and in evaluating the response to treatments. Renal biopsy is the only method capable of providing objective and comparable information on the extent of fibrosis, but it is not suitable for outpatient monitoring of chronic kidney disease due to its invasiveness. Elastosonography is an innovative and non-invasive ultrasound method that allows the measurement of tissue elasticity through the transmission of mechanical waves and the measurement of their propagation speed. Although some authors have demonstrated the usefulness of elastosonographic techniques for the quantification of liver fibrosis, few studies have investigated the applications of elastosonography in renal pathology. Furthermore, the depth of native kidneys, the high anisotropy of the renal tissue, and the possibility of examining only a small region of interest currently limit its spread in clinical practice. The aim of this review is to examine the physical principles of elastosonography and to review the latest evidence about the possible applications of the ARFI (acoustic radiation force impulse) technique in the study of kidney diseases.

Ultrasound is very effective in performing procedures and assessment of complications in peritoneal dialysis. The ultrasound examination can be applied for preoperative assessment, during the peritoneal catheter placement, for the detection and monitoring of infection, as well as for the evaluation of the catheter malfunction. Despite being not only a cost- and time-saving technique but also a bedside procedure, ultrasonography remains an underrated clinical tool in the field of peritoneal dialysis. This publication wants to explain and reinforce the clinical utility of US in PD and to expand the diagnostic equipment for the clinician.

Background: The approach to peritoneal catheter malfunction consists usually in a diagnostic and therapeutic sequence of laxative prescription, abdominal radiography, brushing of the catheter, guide-wire manipulation or fluoroscopy and in the end of a videolaparoscopy (VLS) rescue intervention. Ultrasound (US) is able to find out major causes of peritoneal catheter malfunction, however without a clearly defined diagnostic value. The aim of the study was to validate the diagnostic capability of US in catheter malfunction compared to the diagnostic reference of VLS. Methods: US scans of the subcutaneous and intraperitoneal segment of the catheter were performed prior to a VLS intervention in 40 adult patients presenting persistent catheter malfunction within a prospective multicentre study. Laxative prescription and brushing of the catheter lumen were undertaken prior to US scan. US diagnosis was compared to the corresponding at VLS, kappa coefficient calculated and the causes of mismatch analysed. Results: In US, causes of persistent malfunction were catheter dislocation combined with omental wrapping in 21 cases, omental wrapping without dislocation in 11 cases, dislocation only in 4 cases, adherences to non-omental structures in 3 cases and entrapment in the lateral inguinal fossa in 1 case. The US diagnosis corresponded to the respective at VLS in 36 of 40 cases, resulting in a kappa coefficient of 0.89 (95% CI: 0.78–1.00). The discrepancies were due to improper visualization of the catheter between omentum and intestinal loops, resulting in an erroneous US diagnosis of omental wrapping. Conclusions: This study suggests that US might have a pivotal role in the diagnostic approach to peritoneal catheter dysfunction.

Rectovesical fistula (RVF) is defined as an abnormal communication between the rectum and the urinary bladder, most commonly after an iatrogenic injury during pelvic surgery. Patients with RVF may have various clinical presentations, ranging from fecaluria, pneumaturia, to urine leakage through the anus. The quality of life for patients with this pathology is adversely affected owing to the associated psychological burden. Surgery is the preferred treatment given the low success rates reported for conservative or minimally invasive approaches. Herein, we present a case of a 65-year-old man with RVF after radical prostatectomy successfully treated by a transperineal approach using a modified Martius procedure.

In this paper we exhibit some results concerning operations with higher-order types of asymptotic variation, results lacking in the general theory developed in previous papers, namely: 1) we show to what extent the standard elementary factorization of a regularly-varying function holds true for higher-order variation; 2) we exhibit an important class of higher-order regularly-varying functions requiring no restrictions on the indexes when performing multiplication; 3) we get non-obvious results on the types of higher-order variation for linear combinations. In addition, partial results are obtained concerning the type of higher-order variation of the inverse of a regularly-varying function whose index belongs to a set of “exceptional” values.

BACKGROUND AND AIMS The global burden of chronic kidney disease (CKD) is growing, impacting around 10% of the worldwide population becoming the 5th cause of mortality by 2023, with high cost for the health care system (Glassrock et al. 2017). CKD can be identified using two easy and inexpensive tests (eGFR and ACR). Early stages of CKD are generally asymptomatic, hence challenging clinical recommendations for early detection of CKD. Indeed, a high percentage of patients in primary care are undiagnosed (Zilich et al. 2005). As a result, high-risk individuals, such as those with hypertension, diabetes, a family history of renal disease and cardiovascular disease, require targeted and accessible screening. In a study promoted by the Italian Society of Nephrology (SIN) and the Italian Society of General Practitioners (SIMG), 300 general practitioners (GPs) recruited a cohort of ∼500 thousand patients in the general population, showing that creatinine dosage was requested for only 17% of patients (Minutolo et al. 2008). Of this subgroup, 16% were affected by CKD, but only one out of eight patients was actually identified by the GP as nephropathic, with potential harm to the patient due to possible missed diagnosis. Such study highlighted that, in Italy, a nephrological consultation is usually requested only in 5% of patients with overt nephropathy in the conservative phase (eGFR 30–60), whereas the nephrological referral did not exceed 50% in cases of pre-dialysis disease (eGFR 30–15). With a global lack of CKD specialists, enabling GPs and building successful multidisciplinary teams to play a larger role in early detection and management will assist hospitals and health systems to alleviate the burden. METHOD An observational pilot study was undertaken between 1 May 2021 and 31 October 2021 in the Apulia region, Italy, within a framework called `The Disease Awareness iNnovaTion nEtwork’ (DANTE). We aimed at evaluating the impact of GPs targeted training by specialized nephrologists towards CKD awareness. A first meeting was set up with GPs in which trained nephrologists illustrated to the GPs the KDIGO CKD guidelines. The differences in terms of proportions between the two groups [baseline time (T0) versus time at 6 months (T6)] were evaluated with Pearson's. RESULTS A total of n = 17 854 of patients were enrolled at T0 versus n = 18 661 at T6 from the databases of 17 Apulian GPs who satisfied the entry criterion (having Millewin software installed on their systems). All of the comparisons in terms of percentage patients tested for ACR and eGFR between T0 and T6 resulted in a statistically significant P-value ( CONCLUSION The DANTE pilot study was the first of its kind ever planned in Apulia. All of the diagnostic tests undertaken did register an increase of at least + 42.59% at T6, with an overall median increase of + 72.73%. Therefore, we can argue that teaching devoted to GPs by nephrologist it is able to improve GPs CKD awareness and increase its early diagnosis, which can slow down the progression of CKD, plus providing for high savings given the large cost gap between the early and late stages of CKD (Jommi et al. 2018).

BACKGROUND AND AIMS Vitamin D insufficiency has been associated with decreased bone mineral density (BMD) in kidney transplant patients (KTRs). However, few data on BMD changes due to vitamin D supplementation in long-term KTRs are available. The purpose of our study is to ascertain the effect of 25-OH-vitamin D (25-OH-D) supplementation on the BMD over a follow-up period of up to 3 years in a real-life cohort of long-term KTRs never supplemented with 25-OH-D and not treated with active vitamin D, bisphosphonate and calciomimetics. METHOD Demographic, clinical and laboratory data were collected. Inclusion criteria were: (1) being a recipient of a kidney from a cadaveric or living donor, (2) age ≥ 18 years and (3) no therapy with inactive vitamin D sterols. Patients with parathyroidectomy and/or history of bone fractures were excluded. BMD was evaluated with standard DEXA, performed at baseline (before vitamin D supplementation) and at the end of the study period. BMD was assessed at lumbar vertebral bodies (LV) and right femoral neck (FN) by a single operator. Bone mineral content (BMC) was calculated in grams (g), bone area in centimetres squared (cm2), and BMD in g/cm2 (BMC divided by the area). According to WHO criteria, results were expressed as T-score [standard deviation (SD) relative to young healthy adults] and Z-score (SD relative to age-matched controls). Osteoporosis and osteopenia were defined as T-score ≤−2.5 SD and T-score −2.5 SD, respectively. According to plasma levels, 25-OH-D was supplemented as recommended for the general population. Linear mixed model analysis was implemented to test the impact of 25-OH-D use on Z-score, T-score and BMD changes (dependent variables) adjusted for sex, age, BMI and presence of diabetes. Z-score, T-score and BMD changes were defined as Z-score, T-score and BMD at follow-up, Z-score, T-score and BMD at study inception. RESULTS A total of 118 KTRs consecutive outpatients never supplemented with 25-OH-D, of whom 69 KTRs were untreated (KTRs-free) and 49 were treated (control group) with bisphosphonate (n = 13) and/or calcio-mimetics (n = 11) and/or active vitamin D (n = 29) were enrolled. Clinical and biochemical characteristics are shown in Table 1. At the basal DEXA, the percentage of osteopenia and osteoporosis was 39.0% and 21.2% at LV; 52.5% and 16.9% at FN, respectively. The mean study-period was 27.7 ± 3.4 months. Basal and follow-up Z-score, T-score and BMD at both measurement sites are reported in Table 2. In linear mixed model analysis, a positive interaction of 25-OH-D supplementation on T-score and Z-score changes at the lumbar vertebral bodies was found (P < .05). At the end of the study, no statistical differences in Z-score, T-score and BMD gains were observed. CONCLUSION Prolonged supplementation with 25-OH-D affects Z-score and T-score at LV in long-term KTRs never supplemented with active or inactive vitamin D.

Since their introduction as antidiabetic drugs, SGLT2 inhibitors (SGLT2i) have come a long way, proving to be beneficial on cardiovascular and renal outcomes independently of diabetes status. The benefits go far beyond glycemic control, and both the cardio- and nephroprotection are underpinned by diverse mechanisms. From the activation of tubule glomerular feedback and the consequent reduction in hyperfiltration to the improvement of hypoxia and oxidative stress in the renal cortex, SGLT2i have also been shown to inhibit hepcidin and limit podocyte damage. Likewise, they improve cardiac metabolism and bioenergetics, and reduce necrosis and cardiac fibrosis and the production of adipokines, cytokines, and epicardial adipose tissue mass. In terms of outcomes, the efficacy has been demonstrated on blood pressure control, BMI, albuminuria, stroke, heart disease, and mortality rate due to cardiovascular events. Patients with chronic kidney disease and proteinuria, with or without diabetes, treated with some SGLT2i have a reduced risk of progression. The analysis of subgroups of individuals with specific diseases such as IgA nephropathy has confirmed this solid effect on renal outcomes. Given these overarching activities on such a broad pathophysiological background and the favorable safety profile that goes with the use of SGLT2i, it is now certain that they are changing our approach to clinical interventions for important outcomes with an impressive impact.

Chronic kidney disease (CKD) is an increasing public health problem. Aging is one of the leading causes, particularly in Western countries, but several comorbidities, such as hypertension and diabetes are involved in its pathogenesis. Thus, the treatment of CKD patient is very complex and requires an integrated strategy. In this context, the holistic approach to the CKD patient and not to the disease itself should be the answer. General practitioners, specialists, voluntary associations, and nonprofit organizations, in addition to the family of the patient, all contribute to the patient care. Moreover, due to the low sensitivity of creatinine values in the early stages of renal failure, its diagnosis often occurs in the advanced phases of the disease. Therefore, the health costs for CKD patients are hardly sustainable by health systems. The reorganization of economic and epidemiological data through new models is necessary to allow the sustainability of the system and to ensure medical care for all patients. In this review, we aim to deal with all the issues about patient care, standards of care, and the impact of chronicity from a global perspective in light of the current state of the Italian healthcare system.

Background: Stenosis is the main cause of arteriovenous fistula failure and is due to neointimal hyperplasia. Percutaneous transluminal angioplasty is the gold standard for patients with vascular access stenosis. The aim of the study was to evaluate the efficacy and safety of ultrasound-guided percutaneous transluminal angioplasty in the treatment of native arteriovenous fistula venous stenosis. Methods: The need for intervention was determined by physical examination and duplex ultrasound in 162 patients. All patients with failing or not maturing arteriovenous fistula were treated in the outpatient setting under ultrasound guidance. Procedural success was assessed with repeated post-procedural ultrasound examinations. All procedures were performed under local anesthesia by a single nephrologist and were performed in a single vascular laboratory, while follow-up ultrasound was performed in the dialysis unit of destination. Results: Early technical success was obtained in 95.6% of cases (154 of 162). Complications occurred in 22 patients (13.5%) with no major complication requiring surgical or fluoroscopic endovascular intervention. Primary patency at 6 and 12 months was 84% and 69.8%, respectively. Risk factors for arteriovenous fistula failure/secondary percutaneous transluminal angioplasty were vascular access low blood flow rate and vintage, as well as the need for thrombolysis during the first percutaneous transluminal angioplasty. Conclusion: Ultrasound-guided percutaneous transluminal angioplasty is a valuable tool to treat vascular access stenosis.

Research question Is it possible, by sperm-washing spermatozoa from clinically HPV-positive men, to obtain spermatozoa free of human papillomavirus (HPV) to be employed in assisted reproduction? Design This was an observational study performed on HPV-positive men. Freshly ejaculated semen was collected and readily processed by gradient separation followed by swim-up from the washed pellet. The resulting fractions were seminal plasma, cell pellet, round cells, non-motile spermatozoa and motile spermatozoa. All fractions were then tested for the presence of HPV DNA. Results Of the 15 clinically HPV-positive subjects, 67% were positive in at least one of the seminal fractions. If any postivity was detected, the plasma was always HPV positive. No consistent pattern was observed throughout different samples in the cell pellet, round cell and non-motile spermatozoa fractions. However, after the sperm-wash procedure, the fraction of motile spermatozoa was never found to be HPV-positive. Conclusions The sperm-washing technique, which was previously successfully used to remove human immunodeficiency virus, can efficiently remove HPV from spermatozoa. However, the present study was conducted on a small population so a larger follow-up study is recommended. HPV screening should be performed in sperm samples and, upon HPV positivity, sperm-washing should be considered before assisted reproduction techniques are used.

Kidney transplant recipients (KTRs) are susceptible to low levels of vitamin D, which may be responsible for mineral and bone metabolism disorders and play some role in the occurrence of cardiovascular, metabolic, immunologic, neoplastic, and infectious complications after kidney transplant. Kidney Disease Improving Global Outcomes (KDIGO) guidelines of the year 2017 recommended vitamin D supplementation in the first 12 months after transplant using the same treatment strategies for the general population. However, no recommendations are provided after the first 12 months due to a lack of sufficient data. This review analyses some studies that assessed the vitamin D status of KTRs and the effects of nutritional and active vitamin D supplementation on bone mineral density, cardiovascular disease, proteinuria, and graft function in KTRs.

Background The “awareness gap” and the under-recognition of chronic kidney disease (CKD) by general practitioners (GPs) is well documented. We set a framework to evaluate the impact in primary care of targeted training and networking with nephrologists with regard to CKD awareness in terms of potential increase of the proportion of patients classified according to KDIGO in the general population and in patients with diabetes, hypertension and heart failure. Methods Data were extracted from the Millewin Digital Platform in use by the GPs (N = 17) at baseline (T0, N = 17,854) and after 6 months (T6, N = 18,662) of networking (education, instant messaging and selected joint visits) with nephrologists (N = 2). The following variables were extracted: age, sex, eGFR (estimated glomerular filtration rate), ACR (urinary albumin-to-creatinine ratio), presence of type 2 diabetes, hypertension and heart failure. The proportion of patients detected having an eGFR below 60 mL/min/1.73m2 was also reported as deemed clinically relevant. Results We observed an increase in the use of ACR and eGFR tests in the entire cohort (+ 121% and + 73%, respectively) and in patients with comorbidities. The proportion of patients with eGFR 2 significantly increased from 2.2% to 3.8% in the entire cohort, from 6.3% to 12.7% in patients with diabetes, and from 5.6% to 9.9% in those with hypertension and finally from 10.8% to 23.7% in patients with heart failure. Conclusions Training and network support to GPs by nephrologists can improve CKD awareness and increase its identification in the general population and, even more, in categories at risk. Graphical abstract

We aimed to evaluate ten-year outcomes of penile prosthesis (PP) implantation for the treatment of erectile dysfunction and to assess predictors of early prosthetic infection (EPI). We identified 549 men who underwent 576 PP placements between 2008 and 2018. Univariate and multivariate analyses were used to identify potential predictors of EPI. An EPI predictive nomogram was developed. Thirty-five (6.1%) cases of EPI were recorded with an explant rate of 3.1%. In terms of satisfaction, 82.0% of the patients defined themselves as "satisfied," while partner's satisfaction was 88.3%. Diabetes (P = 0.012), longer operative time (P = 0.032), and reinterventions (P = 0.048) were associated with EPI risk, while postoperative ciprofloxacin was inversely associated with EPI (P = 0.014). Rifampin/gentamicin-coated 3-piece inflatable PP (r/g-c 3IPP) showed a higher EPI risk (P = 0.019). Multivariate analyses showed a two-fold higher risk of EPI in diabetic patients, redo surgeries, or when a r/g-c 3IPP was used (all P < 0.03). We showed that diabetes, longer operative time, and secondary surgeries were the risk factors for EPI. Postoperative ciprofloxacin was associated with a reduced risk of EPI, while r/g-c 3IPP had higher EPI rates without an increased risk of PP explant. After further validation, the proposed nomogram could be a useful tool for the preoperative counseling of PP implantation.

Background The connection between testicular ultrasound (US) parameters and testicular function, including both spermato- and steroidogenesis has been largely suggested, but their predictive properties are not routinely applied. Radiomics, a new engineering approach to radiological imaging, could overcome the visual limit of the sonographer. Objectives This study is aimed at extracting objective testicular US features, correlating with testicular function, including both spermato- and steroidogenesis, using engineering approach, in order to overcome the operator-dependent subjectivity. Materials and methods Prospective observational pilot study from December 2019 to December 2020 on normozoospermic subjects and patients with semen variables alterations, excluding azoospermia. All patients underwent conventional semen analysis, pituitary-gonadal hormones assessment and testicular US, performed by the same operator. US images were analysed by Biolab (Turin) throughout image segmentation, image pre-processing and texture features extraction. Results 170 US testicular images were collected from 85 patients (age 38.6±9.1 years). A total of 44 first-order and advanced features were extracted. US inhomogeneity defined by radiomics significantly correlate with the andrologist definition, showing for the first time a mathematical quantification of a subjective US evaluation. 13 US texture features correlated with semen parameters, predicting sperm concentration, total sperm number, progressive motility, total motility and morphology, and with gonadotropins serum levels, but not with total testosterone serum levels. Classification analyses confirmed that US textural features predicted patients' classification according to semen parameters alterations. Conclusions Radiomics texture features qualitatively describe the testicular parenchyma with objective and reliable quantitative parameters, reflecting both the testicular spermatogenic capability and the action of pituitary gonadotropins. This is an innovative model in which US texture features represent a mirror of the pituitary-gonadal homeostasis in terms of reproductive function. This article is protected by copyright. All rights reserved.

Optimal glycemic control in diabetic patients remains a difficult goal to achieve. Hypoglycemia, nausea and weight gain can compromise the patients' adherence to antidiabetic therapy over time. GLP-1 receptor agonists have been shown to improve glycemic control and reduce the incidence of side effects both when used in monotherapy and in combination with other hypoglycemic drugs. The growing interest of nephrologists in GLP-1 receptor agonists derives from numerous studies showing that not only they positively affect traditional cardiovascular risk factors, but also exert a protective effect on renal function regardless of their hypoglycemic effects, thus delaying the development and progression of diabetic nephropathy. The aim of this paper is to review the latest evidence on pharmacokinetics and pharmacodynamics and the direct and indirect mechanisms through which GLP-1 receptor agonists confer nephroprotection, improving the renal outcomes of diabetic patients.

Contrast-enhanced ultrasound (CEUS) represents one of the most interesting and promising examples of imaging application in clinical practice. Ultrasound contrast media are defined as “blood pool” agents because they remain confined into blood vessels without reaching the excretory tract. They are classified into first and second generation depending on the gas in microbubbles. When the ultrasound beam hits microbubbles in the blood flow, their compressible gas cores oscillate in response to the high-frequency sonic energy field. The microbubbles reflect a unique echo that stands in stark contrast to the surrounding tissue due to the orders of magnitude mismatch between microbubble and tissue echogenicity. Both contrast generations are characterised by an excellent safety profile, with rare hepatic and central nervous system side effects and absent nephrotoxicity thanks to their predominant pulmonary clearance. The clinical utility of CEUS, which is widely recognised in the study of liver diseases, is also becoming relevant to the pathology of other organs, such as genitourinary system, gastrointestinal tract, peripheral vascular system, spleen and lymph nodes, and breast, lung, and endocrine and exocrine glands. Possible applications of CEUS in nephrology include renal ischemia, differential diagnosis of cystic and solid lesions, follow-up of ablative therapies, kidney trauma, kidney transplant, inflammatory diseases, renal artery stenosis, and vesicoureteral reflux.

In the field of peritoneal dialysis contrast enhanced ultrasound (CEUS) is a new add-on examination to B-mode ultrasound, but until recently it has never been systematically studied. Based on the experience of the Project Group "Integrated Imaging and Interventional Nephrology" of the Italian Society of Nephrology, CEUS is helpful for evaluating catheter malfunction, peritoneal-pleural communication, leakage, and herniation, and in particular it facilitates dynamic functional imaging of the catheter and its complications. The use of CEUS in peritoneal dialysis is simple, repeatable, safe, radiation-free, and appears to be less time-consuming and more cost-effective than other radiological imaging techniques such as peritoneography, computed tomography, magnetic resonance or peritoneal scintigraphy.

To assess the diagnostic accuracy of contrast-enhanced ultrasound (CEUS) and computed tomography (CT) within Bosniak IIF/III categories.After cystic renal mass diagnosis by contrast-enhanced CT, all patients with Bosniak score ≥ II also underwent CEUS between March 2017 and March 2019. Their exams were retrospectively analyzed. One experienced uro-radiologist performed every CEUS and reviewed the exams according to the EFSUMB 2020 Position Statement, while blinded to clinical data. CT Bosniak scores were retrospectively given blindly by two uro-radiologists (CT 1 and CT 2). We compared CEUS, CT 1 and CT 2 scores to clinical findings and histological tests. Clinical performance characteristics and area under the receiver operating characteristic (ROC) curves (AUCs) were determined separately for CEUS and CT, and then compared.101 cystic masses were analyzed. In Bosniak categories IIF and III, the AUCs were 0.854 for CT 1, 0.779 for CT 2, and 0.746 for CEUS.Despite some statistical limitations, this study confirms that among cystic renal masses, those classified as Bosniak IIF and III are the most difficult to assess. The diagnostic performances of CEUS and CT are similar within this group. However, in experienced hands, CEUS could be valuable in further evaluation of ambiguous cystic masses, and in more ductile, safer, and cost-effective surveillance of those classified as Bosniak IIF and III. When challenging cystic renal masses occur, CEUS is a useful tool for clinical management and for the follow-up of non-surgical lesions.

The purpose of this paper is to add some complements to the general theory of higher-order types of asymptotic variation developed in two previous papers so as to complete our elementary (but not too much!) theory in view of applications to the theory of finite asymptotic expansions in the real domain, the asymptotic study of ordinary differential equations and the like. The main results concern: 1) a detailed study of the types of asymptotic variation of an infinite series so extending the results known for the sole power series; 2) the type of asymptotic variation of a Wronskian completing the many already-published results on the asymptotic behaviors of Wronskians; 3) a comparison between the two main standard approaches to the concept of “type of asymptotic variation”: via an asymptotic differential equation or an asymptotic functional equation; 4) a discussion about the simple concept of logarithmic variation making explicit and completing the results which, in the literature, are hidden in a quite-complicated general theory.