Prognostic value of high-sensitive cardiac troponin I in asymptomatic chronic hemodialysis patients.

INTRODUCTION: Increased levels of cardiac troponins (cTn) are a hallmark of acute myocardial infarction (AMI), along with symptoms and electrocardiographic (ECG) changes. Stably elevated cTn concentrations are frequently observed in asymptomatic patients with chronic kidney disease (CKD) and/or on hemodialysis (HD); the meaning of this elevation, as assessed by conventional techniques, remains unclear. Aim of our study was to evaluate the clinical significance of cTnI levels in asymptomatic HD patients by employing a newer high-sensitive cTnI (hs-cTnI) assay. METHODS: We enrolled 49 patients undergoing regular HD treatment for more than 3 months; all patients were asymptomatic for chest pain and had no history of acute coronary syndrome in the past 2 months. For every patient we measured hs-cTnI, cTnI and brain natriuretic peptide (BNP) before initiation of one HD session at baseline (T0), after 3 (T1) and 9 months (T2). Demographic, anamnestic, dialytic and echocardiographic characteristics of the examined population were evaluated. We also recorded the number of cardiovascular events from T0 to 12 months after T2. RESULTS: Fifteen patients were lost to follow-up: 6 died, 2 underwent kidney transplantation, 7 did not match the inclusion criteria later during observation. At T0 (49 patients) we observed 14 hs-cTnI positive patients vs. 4 standard c-TnI positive patients (28,5% vs 8,1%); at T1 (40 patients) 16 vs 3 (26.4% vs 7.5%); at T2 (34 pz) 9 vs 0 (26.4% vs 0%). During the study we recorded 10 cardiovascular events, 8 of which in patients that were hs-cTNI positive, leading to death in 3. Hs-cTnI levels were predictive of cardiovascular events at all times and predictive of cardiovascular mortality at T0 and T1 (p < 0.001). In a multivariate analysis, a history of coronary artery disease (CAD) was an independent variable of high hs-cTnI levels at T0 (p < 0.04) and T1 (p < 0.03). CONCLUSIONS: Our study shows that a novel sensitive assay detects more asymptomatic HD patients compared to previously used methods, being at the same time predictive of cardiovascular mortality and morbidity. The only independent variable of high hs-cTnI concentrations was a positive history of cardiovascular disease, suggesting a possible role of hs-cTnI in identifying a high-risk subset of patients.

CHARACTERIZATION OF A SMALL FOV PORTABLE GC: MediPROBE.

In this work, we evaluated the performance of the prototype SFOV MediPROBE developed at the University of Naples Federico II through the protocol proposed by (Bhatia B.S., Bugby S.L., Lees J.E., Perkins A.C. A scheme for assessing the performance characteristics of a small field of-view gamma cameras. Physica. Medica., 31 (1), pp. 98-103. (2015) doi: 10.1016/j.ejmp.2014.08.004). We extensively investigated a new device configuration where the pinhole collimator was placed outside the housing of the probe, in order to increase the system spatial resolution, and the pixel size was doubled, in order to reduce the charge sharing effect. The experimental measurements show that the spatial resolution is enhanced by only about 10%, but the sensitivity decreases strongly. Therefore, the trade-off between these two features does not seem to be advantageous. In addition, our experiments suggest that the charge sharing effect is not completely canceled. Despite these results, the features of this device appear suitable for intraoperative surgical survey. We aim to use this device in the clinical practice for the intraoperative imaging of lymph nodes, breast, thyroid and parathyroid tumors.

Serum Free Light Chains Removal by HFR Hemodiafiltration in Patients with Multiple Myeloma and Acute Kidney Injury: a Case Series.

BACKGROUND/AIMS: Multiple myeloma (MM) represents 10% of all haematologic malignancies. Renal involvement occurs in 50% of MM patients; of them, 12-20% have acute kidney injury (AKI), with 10% needing dialysis at presentation. While hemodialysis (HD) has no effect upon circulating and tissue levels of monoclonal proteins, novel apheretic techniques aim at removing the paraproteins responsible for glomerular/tubular deposition disease. High cut-off HD (HCO-HD) combined with chemotherapy affords a sustained reduction of serum free light chains (FLC) levels. One alternative technology is haemodiafiltration with ultrafiltrate regeneration by adsorption on resin (HFR-SUPRA), employing a "super high-flux" membrane (polyphenylene S-HF, with a nominal cut-off of 42 kD). Aim of our pilot study was to analyze the effectiveness of HFR-SUPRA in reducing the burden of FLC, while minimizing albumin loss and hastening recovery of renal function in 6 subjects with MM complicated by AKI. METHODS: Six HD-dependent patients with MM were treated with 5 consecutive sessions of HFR-SUPRA on a Bellco® monitor, while simultaneously initiating chemotherapy. Levels of albumin and FLC were assessed, calculating the rates of reduction. Renal outcome, HD withdrawal and clinical follow-up or death were recorded. RESULTS: All patients showed a significant reduction of FLC, whereas serum albumin concentration remained unchanged. In three, HD was withdrawn, switching to a chemotherapy alone regimen. The other patients remained HD-dependent and died shortly thereafter for cardiovascular complications. CONCLUSION: Our study suggests that HFR-SUPRA provides a rapid and effective reduction in serum FLC in patients with MM and AKI, while minimizing the loss of albumin. When started early in combination with chemotherapy, blood purification by HFR-SUPRA was followed by the recovery of renal function in half of the patients treated.

Negative predictive value of stress myocardial perfusion imaging and coronary computed tomography angiography: A meta-analysis.

BACKGROUND: Comparing the prognostic value of a negative finding by stress single-photon emission computed tomography myocardial perfusion imaging (MPI) and coronary computed tomography angiography (CCTA) may be useful to evaluate how better identify low-risk patients. We performed a meta-analysis to compare the long-term negative predictive value (NPV) of normal stress MPI and normal CCTA in subjects with suspected coronary artery disease (CAD). METHODS AND RESULTS: Studies published between January 2000 and November 2016 were identified by database search. We included MPI and CCTA studies that followed-up ≥100 subjects for ≥5 years and providing data on clinical outcome for patients with negative tests. Summary risk estimates for normal perfusion at MPI or <50% coronary stenosis at CCTA were derived in random effect regression analysis, and causes of heterogeneity were determined in meta-regression analysis. We identified 12 eligible articles (6 MPI and 6 CCTA) including 33,129 patients (26,757 in MPI and 6372 in CCTA studies) with suspected CAD. The pooled annualized event rate (AER) for occurrence of hard events (death and nonfatal myocardial infarction) was 1.06 (95% confidence interval, CI 0.49-1.64) in MPI and 0.61 (95% CI 0.35-0.86) in CCTA studies. The pooled NPV was 91% (95% CI 86-96) in MPI and 96 (95% CI 95-98) in CCTA studies. The summary rates between MPI and CCTA were not statistically different. At meta-regression analysis, no significant association between AER and clinical and demographical variables considered was found for overall studies. CONCLUSIONS: Stress MPI and CCTA have a similar ability to identify low-risk patients with suspected CAD.

Impaired maturation of arteriovenous fistula for haemodialysis due to forearm artery stenosis: percutaneous endovascular treatment.

INTRODUCTION: Distal autogenous arteriovenous fistula (dAVF), considered the "gold standard" vascular access for haemodialysis, suffers from a high rate of impaired maturation. One of the usual causes is low-flow associated forearm arterial stenosis. In such cases, endovascular treatment by percutaneous transluminal angioplasty represents a helpful option to enable maturation of the vascular access.Currently, there are few reports concerning the treatment of this complication. Therefore, we describe our single-centre experience based on a retrospective review of prospectively collected data. PATIENTS AND METHODS: We treated 18 consecutive patients from July 2007 to January 2014 (16 radio-cephalic, 2 ulno-basilic distal AVF). A low flow due to forearm artery stenosis was diagnosed by duplex examination, as routinely performed one month after dAVF creation. An anterograde trans-brachial access was used for a 4-mm high-pressure angioplasty of the stenosed artery. RESULTS: All interventions resulted in patent fistulas. Isolated percutaneous transluminal angioplasty (PTA) was required without need of stent placement. Mean blood flow increased from 304 mL/min, preoperatively, to 671 mL/min (p<0.01), as checked one week after the procedure. One-year primary and secondary patency were 84% ±7.3% and 92% ± 9.2%, respectively. Under no circumstances did access-induced distal ischemia occurred during follow-up. CONCLUSIONS: Endovascular approach is a helpful and minimally invasive procedure for treatment of delayed maturation of dAVF related to forearm artery stenosis.

Evaluation of the Impact of a New Synthetic Vitamin E-Bonded Membrane on the Hypo-Responsiveness to the Erythropoietin Therapy in Hemodialysis Patients: A Multicenter Study.

BACKGROUND: Oxidative stress has been related to hypo-response to erythropoiesis-stimulating agents (ESAs) in hemodialysis (HD) patients. The aim of this study was to verify whether vitamin E (ViE) on a synthetic polysulfone dialyzer can improve ESA responsiveness. METHODS: This controlled, multicenter study involved 93 HD patients on stable ESA therapy, who were randomized to either ViE-coated polysulfone dialyzer or to a low-flux synthetic dialyzer. The primary outcome measure was the change in ESA resistance index (ERI) from baseline. RESULTS: Mean ERI decreased in the ViE group by 1.45 IU/kg*g/dl and increased in the control group by 0.53 IU/kg*g/dl, with a mean difference of 1.98 IU/kg*g/dl (p = 0.001 after adjusting for baseline ERI, as foreseen by the study protocol). Baseline ERI was inversely related to its changes during follow-up only in the control group (R2 = 0.29). CONCLUSIONS: The ViE dialyzer can improve ESA response in HD patients. Changes in ERI during follow-up are independent from baseline ERI only in the ViE group. Video Journal Club 'Cappuccino with Claudio Ronco' at http://www.karger.com/?doi=453442.

Safety and efficacy of denosumab in osteoporotic hemodialysed patients.

BACKGROUND AND AIMS: In elderly subjects, renal insufficiency and osteoporosis often coexist with high risk of fracture and elevated socio-economic burden. Today a large number of effective anti-osteoporotic drugs are available but generally they are contraindicated in patients with chronic kidney disease (CKD) because of their progressive accumulation. Denosumab, instead, does not require dose adjustments for different degrees of renal impairment so it can be a valid treatment in osteoporotic patients with CKD. Limited data are available in the literature concerning the use of denosumab in hemodialysis (HD). The aim of our study was, therefore, to study the efficacy and tolerability of this drug in this particular subset of patients. METHODS: We retrospectively reviewed the charts of 12 osteoporotic HD patients who received a single 60-mg subcutaneous dose of denosumab every 6 months for an observation period of 24 months. Serum electrolyte, markers of bone turnover and quantitative ultrasound (QUS) were evaluated. RESULTS: Over 24 months, we observed a gradual improvement of bone metabolism: ß-CrossLaps from 2567.08 ± 1264 to 1492.5 ± 1182.5 pg/ml; bone alkaline phosphatase (BALP) from 33.5 ± 28.8 to 11.8 ± 3.7 mcg/l, and of QUS index (T-score from -5.33 ± 1.58 to -4.84 ± 1.2; risk of fracture from 13.9 ± 4.7 to 11.07 ± 5.3 %). Few cases of hypocalcemia were detected, more significant after the first and second injection, but with careful monitoring of serum calcium and rapid therapy adjustment we could easily manage serum Ca levels. CONCLUSIONS: Our pilot experience highlights the safety and efficacy of denosumab in the treatment of osteoporosis in HD patients, potentially supporting its use to reduce the burden of fractures in this patient population.

Cross-Over Efficiency Comparison of Different Tidal Automated Peritoneal Dialysis Schedules.

This study compares 5 different tidal automated peritoneal dialysis (APD) prescriptions. Six low-average and 6 high-average transporters performed 3 separate sessions with 5 different schedules: (A) 50% tidal with initial fill volume (FV) 2 liters, (B) 50% tidal with 2.2 liters initial FV, (C) 2.2 liters initial FV with 70% tidal, (D) as in B, with one complete renewal of the initial FV at midsession, (E) 2.2 liters FV with breakpoint modality. Urea, creatinine and phosphate peritoneal clearances, sodium removal and ultrafiltration (UF) were compared using analysis of variance. Compared to treatment A, all the tested alternative schedules were associated with 10% significantly higher urea clearance; B, D and E, but not C, were associated with 10% higher creatinine clearance. Phosphate clearance was significantly higher with D, while sodium removal was larger with both C and D. UF was lower with A and E in high average transporters. Manipulation of the main prescriptive parameters of tidal APD has significant impact on its efficiency.

Diagnosis and follow-up of idiopathic retroperitoneal fibrosis: role of (18)F-FDG-PET/CT and biochemical parameters in patients with renal involvement.

Idiopathic retroperitoneal fibrosis (IRF) is a rare disease characterized by fibro-inflammatory reaction surrounding ureters and other inner organs with possible secondary renal involvement. Symptoms are aspecific and recurrent phases of activity are generally associated with elevation of inflammatory indices. 18F-FDG-PET is nowadays an important tool for the detection of this disease, allowing differentiation between metabolically active tissue and fibrotic one. The purpose of this study was to investigate the role of 18F-FDG-PET in the management of IRF and to evaluate possible correlations between biochemical parameters and PET/CT findings of disease activity. We enrolled seven consecutive patients with IRF (in five histology proved the disease) observed from 2003 to 2012 (5 M:2 F, mean age 53.8 years, range 44-86 years). All patients presented with fever as first symptom; two had obstructive renal failure requiring hemodialysis; one underwent monolateral nephrectomy for parenchyma infiltration; six presented ureteral involvement; three underwent ureteral stent placement. For each patient, during a mean total follow-up of 26.5 months we evaluated serum creatinine, BUN, Hb, RBCs, WBCs, PLT, CRP, ESR. Periodic 18F-FDG-PET/CT scans (every 5.9 months-mean) were performed in all patients. Statistical evaluation was performed using "stepwise regression" analysis. Steroids and immunosuppressive agents induced a progressive normalization of PET/CT scans in all patients at the end of follow-up. Stepwise regression analysis showed that BUN, serum creatinine and CRP only if considered together, significantly correlated with SUV max (p value = 0.000003057). 18F-FDG-PET is a useful tool for clinical decision making in patient with IRF, allowing to evaluate the efficacy of the pharmacological treatment and to detect early recurrences, to modify the therapeutic approach. Acute phase reactants are not reliable alone for the management and the follow-up as they are often not concordant with metabolic assessment of the disease. In patients with ureteral involvement, CRP together with BUN and serum creatinine has a significant correlation with PET/CT results, and can help physicians in therapeutic approach, better than a single parameter.

Metformin associated lactic acidosis (MALA): clinical profiling and management.

Metformin (MF) accumulation during acute kidney injury is associated with high anion gap lactic acidosis type B (MF-associated lactic acidosis, MALA), a serious medical condition leading to high mortality. Despite dose adjustment for renal failure, diabetic patients with chronic kidney disease (CKD) stage III-IV are at risk for rapid decline in renal function by whatever reason, so that MF toxicity might arise if the drug is not timely withdrawn. Sixteen consecutive patients were admitted to our Hospital's Emergency Department with clinical findings consistent with MALA. Fifteen had prior history of CKD, 60 % of them with GFR between 30 and 60 ml/min. Of these, 5 required mechanical ventilation and cardiovascular support; 3 promptly recovered renal function after rehydration, whereas 10 (62 %) required continuous veno-venous renal replacement treatment. SOFA and SAPS II scores were significantly related to the degree of lactic acidosis. In addition, lactate levels were relevant to therapeutic choices, since they were higher in dialyzed patients than in those on conservative treatment (11.92 mmol/l vs 5.7 mmol/l, p = 0.03). The overall death rate has been 31 %, with poorer prognosis for worse acidemia, as serum pH was significantly lower in non-survivors (pH 6.96 vs 7.16, p > 0.04). Our own data and a review of the literature suggest that aged, hemodynamically frail patients, with several comorbidities and CKD, are at greater risk of MALA, despite MF dosage adjustment. Moreover, renal replacement therapy rather than simple acidosis correction by administration of alkali seems the treatment of choice, based on eventual renal recovery and overall outcome.

Echographic landmark of cephalic and collateral accessory vein at forearm in preoperative evaluation for hemodialysis angioaccess.

INTRODUCTION: Superficial veins in the upper arm differ according to their relationship to the superficial fascia. We investigated the echographic landmark of the cephalic vein (CV) to correctly distinguish it from the collateral accessory vein (CAV) before hemodialysis angioaccess creation. MATERIALS AND METHOD: Twenty consecutive patients were evaluated by ultrasonographic scan. The echographic features of CV and CAV together with their relationship were described. RESULTS: Ninety-five percent of patients presented both CV and CAV (75% CAV laterally located, 25% medially located). CV and CAV diameters were 2.9 (±0.65) and 2.0 (±0.70), respectively. CONCLUSIONS: CV differs from CAV for its anatomic location at forearm. Such a difference is clearly evident under ultrasound examination, despite any recommendation in ultrasound guidelines. Whether the exclusive use of CV for angioaccess creation can lead to a better outcome will be ascertained by further studies.

Preoperative duplex examination in patients with dialysis access-related hand ischemia: indication for distal radial artery ligation.

PURPOSE: To demonstrate that treatment with distal radial artery ligation (DRAL), based on preoperative evaluation with duplex ultrasound, is effective for correction of hand ischemia related to distal radiocephalic arteriovenous fistula (AVF). METHODS: Two patients with symptoms of hemodialysis access-induced distal ischemia (HAIDI) related to radiocephalic AVF at wrist (necrotic lesion of fingers, pain at rest and loss of sensory function) were studied with preoperative duplex examination. Color Doppler ultrasound (CDU) showed low-normal flux (700 and 500 mL/min respectively), retrograde flow in the DRA and increased digital perfusion after manual occlusion of DRA. They were both treated by ligation of the DRA. RESULTS: Both patients had immediate improvement of ischemic symptoms. Reversed DRA flow disappeared and peripheral flow ameliorated. Postoperative AVF flow was 500 and 350 mL/min, stable at 16 and 8 months of follow-up, respectively. CONCLUSIONS: Preoperative CDU examination, simulating reversed DRA flow interruption, seems to be an effective tool to predict the success of DRAL procedure.

Prognostic value of normal stress myocardial perfusion imaging in diabetic patients: a meta-analysis.

BACKGROUND: The prognostic value of normal stress myocardial perfusion single-photon emission computed tomography (MPS) in patients with diabetes has only been evaluated in single-center studies of relatively limited sample size. We performed a meta-analysis of published studies, including diabetic patients with known or suspected coronary artery disease (CAD), to assess the predictive value for adverse cardiac ischemic events of normal stress MPS. METHODS AND RESULTS: Studies published between January 1990 and December 2013 were identified by database search. We included studies using stress MPS to evaluate diabetic patients with known or suspected CAD and providing data on clinical outcomes of non-fatal myocardial infarction or cardiac death with a follow-up time ≥12 months. A total of 14 studies were finally included, recruiting 13,493 patients. The negative predictive value (NPV) for non-fatal myocardial infarction and cardiac death of normal MPS was 94.92% (95% confidence interval 93.67-96.05), during a weighted mean follow-up of 36.24 months, resulting in estimated event rate after a negative test equal to 5.08% (95% confidence interval 3.95-6.33). The corresponding annualized event rate after a negative test was 1.60% (95% confidence interval 1.21-2.04). CONCLUSIONS: Stress MPS has a high NPV for adverse cardiac events in diabetic patients with known or suspected CAD leading to define a "relatively low-risk" patients category.

Creation of autogenous radial cephalic direct wrist access for hemodialysis in the elderly using microsurgery.

PURPOSE: Guidelines recommend autogenous radial-cephalic AV fistula (RCAVF) as the first choice for hemodialysis. Concern has been raised that this is not suitable in the elderly. We assessed the results of microsurgery for RCAVF creation comparatively in patients older and younger than 70 years. METHODS: We prospectively followed 126 patients for three years. After systematic clinical and ultrasound assessment, a RCAVF was created using a surgical microscope. Patency was assessed immediately, at one week, one month and one year. Outcomes were recorded and stratified into two groups: <70y and >70y. RESULTS: RCAVF was created in 75.4% and 70.8% of the <70y and >70y groups, respectively. Incidence of early failure was 11% (<70y) and 13% (>70y). Primary and secondary patency at one year was 67% and 84% (<70y) versus 63% and 80% (>70y). CONCLUSIONS: Microsurgery enabled the creation of RCAVF in >70y with acceptable risk of failure and slight differences by comparison with <70y. Older age should not preclude RCAVF creation.

Hemodialysis in patients requiring 131I treatment for thyroid carcinoma.

PURPOSE: Thyroid malignancies can be treated by surgery followed by ablation of the remnant tissue with 131I. As iodide removal from the body occurs by renal extraction, in patients suffering from end-stage renal disease it is necessary to properly evaluate both timing and method of the extracorporeal treatment.
 METHODS: We present two patients on regular hemodialysis, admitted in isolation to the Nuclear Medicine Department and treated with 131I for thyroid carcinoma diagnosed during the check-up for transplantation. Both patients underwent two hemodialysis sessions with a portable machine for CRRT (continuous renal replacement therapy), 24 and 48 hours after the administration of 50 mCi of 131I. The nursing staff were monitored with a dosimeter. Radioactivity of the patients, dialysate and urines were measured during hemodialysis. 
 RESULTS: The greater reduction was obtained with the first dialysis, but in both patients a further, though shorter, hemodialysis at 48 hours was necessary for reaching a patient's radioactivity compatible with discharge. Radioactivity measured in the dialysate demonstrated the almost total removal of radioiodine by dialysis alone. In both patients, follow-up exams revealed a complete ablation of thyroid tissue, without signs of local recurrence. The dose of radioactivity of the dialysis staff was below allowable limits. 
 CONCLUSIONS: We conclude that a successful reduction of radioactivity, without dispersing its therapeutic efficacy, can be obtained with daily hemodialysis with a CRRT machine in patients in isolation treated with 131I. A therapeutic model is proposed.

TRP channels as therapeutic targets in kidney disease and hypertension.

The Drosophila trp homologue Transient Receptor Potential (TRP) cation channels are ubiquitous in most species and cell types. The functional TRP subclasses TRPC, TRPV and TRPP gate Ca2+ and other cations in mammalian tissues, including the kidney. It is now clear that TRP channels play an important role in renal physiology and in certain genetic disorders of the kidney. Hence, there is considerable interest in targeting mutated or dysfunctional TRP channels in an effort to treat such diseases. Transcellular epithelial cell Ca2+ reabsorption occurs in the distal tubule via luminal TRPV5/V6 channels. Indeed, TRPV5 KO mice display phenotypic defects of renal disease, including hypercalciuria and impaired bone mineral density. Similar to Ca2+, Mg2+ transcellular reabsorption occurs in the distal convoluted tubule via apical TRPM6/TRPM7 channels. TRPC6 is a component of the glomerular podocyte "slit diaphragm" and its autosomic dominant mutation has been linked to a familial, steroid-resistant form of nephrotic syndrome. A more common inherited disorder of the tubular epithelium, autosomal dominant polycystic kidney disease (ADPKD), is at least in part related to mutation of polycystin 2 (PC2), a protein encoded by the PKD2 gene. PC2 is now identified as TRPP2, a Ca(2+)-permeable non-selective cation channel located on the cilia of tubular epithelial cells. TRP-related ion transport may also play a role in the pathogenesis of arterial systemic and/or pulmonary hypertension through regulation of vascular smooth muscle contraction, renal perfusion/hemodynamics, as well as the total body balance of divalent cations. Thus, multiple renal TRP channels are potential targets for pharmacological intervention aimed at preventing or attenuating the burden of chronic kidney disease.

Relation between right and left ventricular function in patients undergoing chronic dialysis.

AIMS: Occurrence of heart failure during dialysis treatment is associated with high mortality. However, mechanisms underlying left ventricular dysfunction (LVD) in these patients are still elusive. In patients undergoing haemodialysis, arteriovenous fistula (AVF) is associated with right ventricular dysfunction (RVD) and a further impairment is observed when AVF is brachial rather than radial. However, it is not known whether AVF-induced RVD is associated with an impaired left ventricular function. We studied the relation between right and left ventricular function in 120 patients undergoing either haemodialysis or peritoneal dialysis and 100 healthy age-matched controls. METHODS: Echocardiography including tissue Doppler imaging (TDI) was performed for both ventricles. Average myocardial performance index (MPI) of the right ventricle (RV MPI) was obtained with a multisegmental approach by using TDI. RESULTS: RVD was higher in haemodialysis than peritoneal dialysis patients and a further increase was observed in haemodialysis patients with brachial access. Interestingly, RV MPI inversely correlated with indices of both left ventricular contraction and relaxation and the association was even stronger in haemodialysis patients, particularly in those with brachial AVF. Of note, dialysis patients in the upper tertile of RV MPI showed the larger impairment of left ventricular function. Regression analyses showed that RV MPI was independently associated with reduced left ventricular function. By contrast, LVD did not significantly affect right ventricular performance in this setting. CONCLUSION: AVF-induced RVD may contribute to LVD in dialysis patients. AVF plays a pivotal role in triggering LVD via right-to-left ventricular interdependence.

Preventive hemostasis for hemodialysis vascular access surgical reinterventions.

Surgical reinterventions for treatment of complications or ligation of haemodialysis vascular access (VA), when performed in or below the mid/lower part of the upper arm, could benefit from the use of preventive haemostasis with an inflatable tourniquet. This technique offers several advantages, such as the reduced risk of bleeding and the increased accuracy of dissection allowing for a minimally invasive approach. The use of preventive haemostasis is safe, economical and time-saving. All the secondary procedures on VA that could benefit from its use are reviewed.

Assessment of long-term vasoplegia induced by brachial plexus block: a favorable effect for hemodialysis angioaccess surgery?

PURPOSE: Loco-regional anesthesia, along with the neurosensitive inhibition causes arterial and venous vasodilatation, that could be of interest for vascular access surgery. We evaluated the long term vasoplegia persistence after brachial plexic block. METHODS: Five patients submitted to brachial plexus block for an orthopedic procedure have been observed. Both radial arteries, that of the blocked arm and the opposite as a control, were analyzed by ultrasound examination, at time 0 and 360 minutes after anesthesia induction. All patients were treated with the same anesthesiologic protocol: axillary approach, use of an electroneurostimulator, injection 10 ml of ropivacain 7.5% + 10 ml of mepivacain 2%. The parameters evaluated from the arterial ultrasound flowmetry were: peak systolic velocity (PSV), end diastolic velocity (EDV) and resistance index (RI). RESULTS: No modification of the arterial flow were observed in the control arm at 0 and 360'after block induction. The blocked arm instead showed a significant decrease of the resistive index, stable at 360 minutes. CONCLUSIONS: The vasoplegia accompaning plexic block lasted 6 hours after anesthesia induction. Whereas this longstanding haemodynamic effect is beneficial for early patency of vascular access for hemodialysis, needs to be ascertained by further investigations.