[Show abstract][Hide abstract] ABSTRACT: 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.
Twenty consecutive patients were evaluated by ultrasonographic scan. The echographic features of CV and CAV together with their relationship were described.
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.
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.
The journal of vascular access 06/2015; DOI:10.5301/jva.5000443 · 1.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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).
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.
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.
Preoperative CDU examination, simulating reversed DRA flow interruption, seems to be an effective tool to predict the success of DRAL procedure.
The journal of vascular access 01/2015; DOI:10.5301/jva.5000341 · 1.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
The journal of vascular access 08/2013; DOI:10.5301/jva.5000165 · 1.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: To assess the efficacy of a Limberg skin flap to treat non-infected necrosis and bleeding at angioaccess puncture sites.
Retrospective analysis of 40 selected (no infection, necrosis <20 mm diameter) patients (25 arteriovenous fistulae [AVF], 15 grafts) treated between 1998 and 2012 by rhomboid excision, vessel repair, and a locally rotated full-thickness Limberg skin flap together with early postoperative percutaneous transluminal angioplasty (PTA; n = 23/40). Success was defined as wound healing and angioaccess patency without complications.
Success rates at 1 and 6 months were 96% (24/25) and 76% (19/25), respectively, for AVF, and 80% (12/15) and 40% (6/15) for arteriovenous grafts. Complications included flap necrosis (n = 2), graft thrombosis (n = 4), minor sepsis (n = 1), death (n = 2), and new puncture site necrosis (n = 3). Four patients were lost to follow-up.
Vessel or graft repair, PTA for distal stenoses and local debridement followed by a Limberg skin flap for tissue defects prevented further bleeding and maintained vascular access patency in 25/40 (62%) patients.
European journal of vascular and endovascular surgery: the official journal of the European Society for Vascular Surgery 06/2013; 46(3). DOI:10.1016/j.ejvs.2013.05.021 · 3.07 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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
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.
The International journal of artificial organs 05/2013; 36(6). DOI:10.5301/ijao.5000192 · 1.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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 Ca2+-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.
Current topics in medicinal chemistry 02/2013; 13(3). DOI:10.2174/15680266112129990084 · 3.45 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
The journal of vascular access 09/2012; 14(2). DOI:10.5301/jva.5000104 · 1.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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.
(C) 2012 Italian Federation of Cardiology
Journal of Cardiovascular Medicine 08/2012; Publish Ahead of Print(4). DOI:10.2459/JCM.0b013e32834eacf0 · 1.51 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: 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 360minutes. 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.
The journal of vascular access 01/2012; 13(3):296-8. DOI:10.5301/jva.5000044 · 1.02 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In a comprehensive evaluation of dialysis adequacy, major attention has been recently paid to fluid and Na balance. Removal of Na has been reported to be significantly poorer with automated peritoneal dialysis (APD) than with continuous ambulatory peritoneal dialysis. Only limited data on Na removal with tidal APD have been published. We analyzed peritoneal Na mass balance in 122 separate nightly tidal APD sessions performed by 7 peritonitis-free, clinically stable, patients with negligible residual renal function (< 100 mL urine daily). Correlations with other efficiency measures [ultrafiltration (UF) and small-solute clearances], prescriptive parameters [duration of treatment, initial intraperitoneal fill volume (IPV) and its tidal percentage, and dialysate flux] and peritoneal transport status were tested in univariate and multivariate linear regression models. Removal of Na was 89 +/- 55 mmol per treatment, which correlated with UF (r = 0.29, p = 0.001) and was higher in patients with high-average transport (118 +/- 41 mmol vs. 81 +/- 56 mmol in low-average transporters, p = 0.0004), in whom a significant positive correlation was found with initial IPV and duration of treatment (r = 0.55; 95% confidence interval: 0.21 to 0.77; p = 0.0029; and r = 0.66; 95% confidence interval: 0.38 to 0.83; p = 0.0002 respectively). Removal of Na correlated weakly with UF in tidal APD and showed wide inter-patient variability. It should therefore be measured rather than roughly estimated from UF. Its magnitude exposes the anuric patient on nightly APD with a "dry" day to the risk of Na retention, unless controlled Na intake or dialytic strategies aimed at enhancing Na removal, or both, are implemented.
Advances in peritoneal dialysis. Conference on Peritoneal Dialysis 01/2012; 28:16-20.
[Show abstract][Hide abstract] ABSTRACT: Background. The value of incremental peritoneal dialysis (PD) as a bridge to renal transplantation (Tx) has not been specifically addressed.
Methods. All consecutive Stage 5 CKD patients with at least 1 year predialysis followup, starting incremental PD or HD under our care and subsequently receiving their first renal Tx were included in this observational cohort study. Age, gender, BMI, underlying nephropathy, residual renal function (RRF) loss rate before dialysis and RRF at RRT start, comorbidity, RRT schedules and adequacy measures, dialysis-related morbidity, Tx waiting time, RRF at Tx, incidence of delayed graft function (DGF), in-hospital stay for Tx, serum creatinine at discharge and one year later were collected and compared between patients on incremental PD or HD before Tx.
Results. Seventeen patients on incremental PD and 24 on HD received their first renal Tx during the study period. Age, underlying nephropathy, RRF loss rate in predialysis, RRF at the start of RRT and comorbidity did not differ significantly. While on dialysis, patients on PD had significantly lower epoetin requirements, serum phosphate, calciumxphosphate product and better RRF preservation. Delayed graft function (DGF) occurred in 12 patients (29%), 1 on incremental PD and 11 on HD. Serum creatinine at discharge and 1 year later was significantly higher in patients who had been on HD.
Conclusions. In patients receiving their first renal Tx, previous incremental PD was associated with low morbidity, excellent preservation of RRF, easier attainment of adequacy targets and significantly better immediate and 1-year graft function than those observed in otherwise well-matched patients previously treated with HD.
[Show abstract][Hide abstract] ABSTRACT: The syndrome of inappropriate ADH secretion (SIADH), also recently referred to as the "syndrome of inappropriate antidiuresis", is an often underdiagnosed cause of hypotonic hyponatremia, resulting for instance from ectopic release of ADH in lung cancer or as a side-effect of various drugs. In SIADH, hyponatremia results from a pure disorder of water handling by the kidney, whereas external Na+ balance is usually well regulated. Despite increased total body water, only minor changes of urine output and modest edema are usually seen. Renal function and acid-base balance are often preserved, while neurological impairment may range from subclinical to life-threatening. Hypouricemia is a distinguishing feature. The major causes and clinical variants of SIADH are reviewed, with particular emphasis on iatrogenic complications and hospital-acquired hyponatremia. Effective treatment of SIADH with water restriction, aquaretics, or hypertonic saline + loop diuretics, as opposed to worsening of hyponatremia during parenteral isotonic fluid administration, underscores the importance of an early accurate diagnosis and careful follow-up of these patients.
[Show abstract][Hide abstract] ABSTRACT: While chronic dialysis treatment has been suggested to increase pulmonary pressure values, right ventricular dysfunction (RVD) is a major cause of death in patients with end-stage renal disease. We investigated the impact of different dialysis treatments on right ventricular function.
We examined 220 subjects grouped as follows: healthy controls (n = 100), peritoneal dialysis (PD; n = 26), hemodialysis (HD) with radial arteriovenous fistula (AVF; n = 62), and HD with brachial AVF (n = 32). Echocardiography including tissue Doppler imaging (TDI) of the right ventricle was performed in all patients.
Pulmonary pressure values progressively rose from controls across the 3 dialysis groups (21.7 ± 6.8, 29.7 ± 6.7, 37.9 ± 6.7 and 40.8 ± 6.6 mm Hg, respectively; p < 0.001). TDI indices of right ventricular function were more impaired in HD patients, particularly in those with brachial AVF. RVD, assessed by TDI myocardial performance index, was higher in HD patients compared with PD patients (71.3 vs. 34.6%, p < 0.001). Moreover, the prevalence of RVD further increased in patients with brachial AVF compared with the radial access (90.6 vs. 61.3%, p < 0.001).
Compared to DP, HD increases the risk of RVD, particularly in the presence of brachial AVF. TDI may detect early functional failure of the right ventricle in HD patients.
American Journal of Nephrology 09/2010; 32(5):432-8. DOI:10.1159/000320755 · 2.65 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Juvenile psoriatic arthritis was diagnosed in a girl of 15 and a half years old, who presented with severe poly-arthritis and psoriasis. Treatment with etanercept 25 mg by subcutaneous injections, twice a week was started. After 5 months of treatment, she developed microscopic hematuria, proteinuria and progressive acute renal failure with anaemia and hypertension. Renal histology, IF, and EM findings were consistent with severe extracapillary crescentic pauciimmune glomerulonephritis. The histology findings, the onset of renal symptoms after beginning treatment with etanercept, and the absence of any abnormality in the urine tests before administration of the drug, support the hypothesis of a rare case of secondary nephropathy due to treatment with an anti-TNF-alpha drug.
Clinical and experimental rheumatology 01/2010; 28(1):91-3. · 2.97 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Haemodialysis has direct and indirect effects on skin and muscle microcirculatory regulation that are severe enough to worsen tolerance to physical exercise and muscle asthenia in patients undergoing dialysis, thus compromising patients' quality of life and increasing the risk of mortality. In diabetes these circumstances are further complicated, leading to an approximately sixfold increase in the incidence of critical limb ischaemia and amputation. Our aim in this study was to investigate in vivo whether haemodialysis induces major changes in skeletal muscle oxygenation and blood flow, microvascular compliance and tissue metabolic rate in patients with and without diabetes.
The study included 20 consecutive patients with and without diabetes undergoing haemodialysis at Sant Andrea University Hospital, Rome from March to April 2007. Near-infrared spectroscopy (NIRS) quantitative measurements of tissue haemoglobin concentrations in oxygenated [HbO2] and deoxygenated forms [HHb] were obtained in the calf once hourly for 4 hours during dialysis. Consecutive venous occlusions allowed one to obtain muscular blood flow (mBF), microvascular compliance and muscle oxygen consumption (mVO2). The tissue oxygen saturation (StO2) and content (CtO2) as well as the microvascular bed volume were derived from the haemoglobin concentration. Nonparametric tests were used to compare data within each group and among the groups and with a group of 22 matched healthy controls.
The total haemoglobin concentration and [HHb] increased significantly during dialysis in patients without and with diabetes. Only in patients with diabetes, dialysis involved a [HbO2], CtO2 and increase but left mVO2 unchanged. Multiple regression StO2 analysis disclosed a significant direct correlation of StO2 with HbO2 and an inverse correlation with mVO2. Dialysis increased mBF only in diabetic patients. Microvascular compliance decreased rapidly and significantly during the first hour of dialysis in both groups.
Our NIRS findings suggest that haemodialysis in subjects at rest brings about major changes in skeletal muscle oxygenation, blood flow, microvascular compliance and tissue metabolic rate. These changes differ in patients with and without diabetes. In all patients haemodialysis induces changes in tissue haemoglobin concentrations and microvascular compliance, whereas in patients with diabetes it alters tissue blood flow, tissue oxygenation (CtO2, [HbO2]) and the metabolic rate (mVO2). In these patients the mVO2 is correlated to the blood supply. The effects of haemodialysis on cell damage remain to be clarified. The absence of StO2 changes is probably linked to an opposite [HbO2] and mVO2 pattern.
Critical care (London, England) 11/2009; 13 Suppl 5(Suppl 5):S9. DOI:10.1186/cc8007