Hemodynamic impact of VASQ device in vascular access creation.

BACKGROUND: Native arteriovenous fistula is the preferred vascular access in term of functionality, efficiency and complication rate. Nevertheless, research continues to seek strategies to reduce the risk of neointimal hyperplasia and hemodynamic modification. The aim of the study was to evaluate the impact on hemodynamic of the VasQ device in arteriovenous fistulae creation. METHODS: The analysis included patients who underwent to fistula creation with or without implantation of the VasQ device between May and September 2019. The hemodynamic parameters were evaluated pre-operatively and at a follow-up of 1, 3, 6 months. The patency and complication rate were evaluated. RESULTS: Fifteen VasQ devices were implanted during 30 arteriovenous fistula surgery. The baseline patients features were similar between groups (VasQ treated/control). At baseline, preoperative arterial flow was similar; radial artery diameter at surgical site was 3.4 ± 0.8 mm in treated and 2.8 ± 0.5 mm in the control group. The mean arterial flow at 1 month was 480 ± 210 mL/min in treated and 561 ± 27 mL/min in the control group. At 3 months the mean arterial flow in treated was 645 ± 143 mL/min versus 824 ± 211 mL/min (p = 0.02) in the control group; at 6 months the arterial flow was 714 ± 146 mL/min versus 810 ± 194 mL/min (p = 0.05) in control group. The cardiac output flow at 6 months in the treated group was 4458 ± 928 mL/min versus 5599 ± 1355 mL/min (p = 0.05) in the control group. At 6 months the primary patency was 73% and 80% and the secondary patency 80% and 86% in treated compared to the control group, respectively. No VASQ device complications were recorded. CONCLUSION: The analysis of these data suggested that using VasQ device could be protective against the hemodynamic modification that occur during arteriovenous fistulae creation.

[Neprilysin inhibition and chronic kidney disease]. / Gli inibitori della Neprilisina nei pazienti affetti da Malattia Renale Cronica e Sindrome Cardio:Renale.

Patients with chronic kidney disease (CKD) have a higher incidence of cardiovascular (acute and chronic) events, which in turn have an increased risk of progression to end-stage renal disease (ESRD) Inhibition of neprilysin, in addition to offering a new therapeutic target in patients with heart failure, could represent a potential improvement strategy in cardiovascular and renal outcome of patients with CKD. Inhibition of neprilysin by inhibiting the breakdown of natriuretic peptides, increases their bioavailability resulting in an increase in diuresis and sodium excretion and, in addition to exerting an inhibition of the renin-angiotensin-aldosterone (RAAS) system. Inhibition of RAAS, in turn, generates a series of counter-regulations that can balance the adverse effects present in CKD and heart failure (HF). The idea of blocking neprilysin is not very recent, but the first drugs used as inhibitors had an inadmissible incidence of angioedema. Among the latest generation molecules that can perform a specific inhibitory action on the neprilysin receptor and, at the same time, on the angiotensin II receptor thanks to the association with valsartan there is the LCZ696 (sacubitril / valsartan). This drug has shown promising benefits both in the treatment arterial hypertension and heart failure. It is hoped that equally positive effects may occur in CKD patients, particularly those with macroproteinuria.

[Chronic kidney disease and sudden death]. / Malattia renale cronica e morte cardiaca improvvisa: dati epidemiologici, fisiopatologia e strategie d'intervento.

Cardiovascular disease represents the major cause of death in chronic kidney disease patients accounting for about 43% of all mortality causes among hemodialysis patients. Sudden cardiac death (SCD) is one of the most frequent and dangerous clinical syndrome occurring in end stage renal disease (ESRD) patients. Hemodialysis patients present a great number of non traditional risk factors for cardiovascular disease such as left ventricular hypertrophy, coronary artery disease, rapid electrolyte shifts, QT dispersion, sympathetic hyperactivity and hyperphosphatemia. The aim of the following review is to summarize epidemiological aspects and pathophysiological pathways of SCD in CKD patients, defining prevention and treatment guidelines.

Penile calciphylaxis in end stage renal disease.

Calciphylaxis, better described as "Calcific uremic arteriolopathy" (CUA), involves about 1-4% of hemodialysis patients all around the world with high mortality rates. We describe a rare clinical case of CUA in peritoneal dialysis patient associated with urological disease. Penile calciphylaxis represents rare clinical complication, and an early diagnosis and multidisciplinary approach are requested. Pathogenesis is still unclear, and therapeutic approaches need more long-term clinical trials to test their efficacy and safety.

Progression of cardiac valve calcification and decline of renal function in CKD patients.

BACKGROUND: No study has evaluated the efficacy of non-calcium-containing phosphate binders in slowing progression of cardiac valve calcification or deterioration of kidney function in patients with chronic kidney disease not on dialysis. This study addressed these issues. METHODS: Outpatients (n = 170) with stage 3-4 chronic kidney disease and either mitral or aortic valve calcification were evaluated in this single-center, single-arm, prospective observational study. Patients received sevelamer hydrochloride (1,600 mg/day) for 1 year. Cardiac valve calcification progression was assessed by echocardiography, and decline of renal function by estimated glomerular filtration rate. Parathyroid hormone, FGF-23 and C-reactive protein (CRP) serum concentration and urinary phosphorus excretion were assayed. RESULTS: At the end of treatment with sevelamer (12th month), mitral valve calcification had decreased by 79.3% from baseline. At baseline, 69 patients had grade 1, 97 patients grade 2 and 4 patients grade 3 calcification scores; at the end of the study, 60 patients showed grade 1, and no mitral valve calcification was registered in the remaining patients. An aortic valve score of 1 was found in 32%, score of 2 in 58%, score of 3 in 9% and score of 4 in 1% of patients at baseline; at the end of the study, a score of 1 was found in 95% and a score of 2 in 5% of patients. Significant slowing down of renal function decline (p<0.001), reduction of FGF-23 and CRP concentration (p<0.0001) and phosphorus excretion (p<0.0001) were observed. CONCLUSIONS: One-year treatment with a non-calcium-containing phosphate binder may hamper the progression of cardiac valve calcification and slow the decline of renal function, as well as reduce serum concentration of FGF-23 and CRP and urinary phosphorus excretion.

[Assessment of right ventricular function in patients with chronic kidney disease stage IV NKF]. / Valutazione della funzione ventricolare destra in pazienti affetti da malattia renale cronica in stadio I-V NKF.

Cardiovascular diseases are accountable for almost 50% of over-all mortality rates in chronic kidney disease (CKD) patients, especially in those who undergo hemo-dialysis or peritoneal dialysis.Hemodialysis patients present higher rates of pulmonary hypertension (PH), an independent risk factor for cardiovascular mortality among this patient population, due in part to the presence and hemodynamic effects of vascular access (both artero-venous fistula and central venous catheter). Echocardiographic TAPSE (tricuspid annular plane systolic excursion) index represents a helpful tool for investigation of right ventricular function together with PAPs (systolic pulmonary artery pressure) evaluation.The following study protocol, introduced by the Cardionephrology Study Group of the Italian Society of Nephrology, aims to evaluate the incidence of right ventricular dysfunction and PH in CKD patients. This is a multicentric, case- control study which includes two arms, each comprising 200 patients, and which will last 24-36 months.Glomerular filtration rates (GFR) are calculated using the eGFR EPI equation, while echocardiographic evaluation includes atrial and ventricular dimension and area, left ventricular systolic function (ejection fraction), diastolic function, TAPSE index measurement and PAPs evaluation.

[Pathophysiology and diagnosis of cardio-renal syndrome: actual picture and future prospectives]. / Fisiopatologia e diagnosi della sindrome cardio-renale: stato dell'arte e prospettive future.

The cardiorenal syndrome (CRS) indicates how close the relationship is between heart and kidney during failure of these organs. At present, the classification of the syndrome includes five types of CRS: types I and II which are strictly related to initial heart failure (both acute and chronic), types III and IV which include initial kidney failure, and type V which includes several systemic diseases. Many pathophysiological pathways have been described illustrating how heart and kidney disease are involved in clinical conditions. The diagnosis of CRS is based on both blood tests and ultrasound imaging. Several biomarkers indicating levels of heart and kidney function have emerged over the last few decades which can be used to predict kidney failure in patients with acute or chronic heart disease. Kidney injury biomarkers have also to be tested, especially those indicating glomerular and tubular damage. Renal ultrasound and trans-thoracic echocardiography can provide further information on heart and kidney failure in patients with cardio-renal syndrome at any stage.

[The future of the ultrasonography techniques in nephrology]. / Il futuro delle tecniche ultrasonografiche in nefrologia.

Thanks to the wide geographical diffusion, low cost and lack of ionizing radiation, ultrasound is now the most widely used imaging technique in clinical practice, second only to chest radiography. Recent technological innovations and introduction of ultrasound contrast agents, further expanded the fields of application of ultrasound, guarantying for the future to this technique an important role in imaging of the urinary tract. The nephrologist must be able to exploit the potential offered by technological innovations in ultrasound imaging for the study of the kidney. The proper management of equipment, in fact, allows to obtain ultrasound images in gray scale of the highest quality, to optimize the diagnostic accuracy of Doppler techniques and take full advantage of the tools offered by means of ultrasound contrast agents.

[Microbubbles: current state and future prospects]. / Le microbolle: attualita' e prospettive future.

Contrast-enhanced ultrasound (CEUS) represents one of the most interesting applications of traditional medical sonography. Ultrasound contrast agents are classified into first- and second-generation agents depending on the gas (nitrogen, perfluorocarbon or sulfur hexafluoride) in the microbubbles. Both generations are characterized by an excellent safety profile, with low hepatic and renal toxicity and rare central nervous system reactions. The respiratory and hepatic elimination of the gases explains the low nephrotoxicity. CEUS has been successfully employed in drug and gene delivery. Indeed, new molecules such as liposomes, micelles and perfluorocarbon nanoparticles have been recently proposed as ultrasound contrast agents. Possible future applications of liposomes are the treatment of hypertension complications (given the possibility to fill them with nitric oxide), the treatment of cerebral disease with xenon, and the treatment of breast and liver cancer with doxorubicin. Micelles have been demonstrated to be effective in cancer treatment as well. Finally, perfluorocarbon nanoparticles can be used in oncological settings and in pancreatic islet transplantation in patients with type I diabetes.

[Contrast enhanced ultrasound in renal diseases]. / L'imaging ecocontrastografico nella patologia renale.

Contrast-enhanced ultrasound (CEUS) is one of the most interesting and promising clinical applications of imaging and ultrasound. Thanks to the absence of ionizing radiation, the lack of nephrotoxicity and low cost it has the potential to become a reference in imaging of the kidney. This review, besides providing a brief description of the proper methodology, presents possible applications of CEUS in nephrology and urology, including renal ischemia, the differential diagnosis of cystic and solid lesions, follow-up of ablative therapies, kidney trauma, kidney transplant, inflammatory diseases, ischemic nephropathy and vesicoureteral reflux.

[Ultrasound assessment in renal infections]. / L'ecografia nelle infezioni del rene.

Urinary tract infections (UTIs) are a common clinical problem, especially among women. Ultrasound assessment is indicated in case of complicated UTIs, in particular in children, pregnant women and patients with chronic kidney disease. Even though B-mode imaging alone is rarely diagnostic in case of particular kidney infections such as focal and multifocal acute pyelonephritis, Doppler and power-Doppler (PD) techniques are able to increase its sensitivity. Contrast-enhanced ultrasound (CEUS) further improves the signal-to-noise ratio, thus increasing the diagnostic accuracy of ultrasound in case of renal infectious disease. Recent studies performed on kidney transplant recipients have indeed demonstrated the high sensitivity and specificity of CEUS in diagnosing acute pyelonephritis. Moreover, ultrasonography is a useful diagnostic tool in case of kidney abscesses, emphysematous pyelonephritis, early phases of pyonephrosis, and in the evaluation and monitoring of echinococcal cysts. Ultrasound imaging is less specific in diagnosing xanthogranulomatous pyelonephritis, malacoplakia and renal tuberculosis. Finally, several authors recommend routine ultrasound assessment in HIV patients, given the high incidence of renal complications in this population of patients.

[Vascular complications following kidney transplant: the role of color-Doppler imaging]. / Le complicanze vascolari del rene trapiantato: il ruolo dell'eco-color-Doppler.

The progressive decline in the incidence of graft rejection has made urological, surgical, parenchymal and vascular complications of kidney transplant more frequent. The latter, although accounting for only 5-10% of all post-transplant complications, are a frequent cause of graft loss. Ultrasonography, both in B-mode and with Doppler ultrasound, is an important diagnostic tool in case of clinical conditions which might impair kidney function. Even though ultrasonography is considered fundamental in the diagnosis of parenchymal and surgical complications of the transplanted kidney, its role is not fully understood in case of vascular complications of the graft. The specificity of Doppler ultrasound is very important in case of stenosis of the transplanted renal artery, pseudoaneurysms, arteriovenous fistulas, and thrombosis with complete or partial artery or vein occlusion. Doppler and color determinations present high diagnostic accuracy, which is higher in case of successive measurements performed during the follow-up of the graft. Modern techniques including contrast-enhanced ultrasound increase the diagnostic power of ultrasonography in case of vascular complications of the transplanted kidney, planted kidney.

[Echocardiography in nephrology]. / L'ecocardiografia in nefrologia.

Cardiovascular disease is the main cause of mordibity and mortality in patients with chronic kidney disease (CKD) affected by a series of risk factors (hypertension, anemia, left ventricular hypertrophy, cardiac failure and dyslipidemia). The combined presence of these factors raises the cardiovascular risk in CKD patients considerably compared with that of the general population. Nephrologists can play a role in preventing and treating these risk factors and thereby delaying the development of CKD. In preventing CKD, nephrologists who practice ultrasound techniques should have basic know how of echocardiography so that they can screen CKD patients for early referral to a cardiologist. Echocardiography is a noninvasive ultrasound technique that requires adequately trained doctors to perform it. Nephrologists who practice it need to obtain good training and postgraduate certification of competence in echocardiography. These nephrologists should team up with cardiologists rather than replace them, and at the same time be aware that they possess the basic knowledge to manage cardiovascular disease in CKD patients.