C. Raimondi

Standard heparin versus low-molecular-weight heparin. A medium-term comparison in hemodialysis.

Background: To compare standard heparin (SH) and low molecular weight heparin (LMWH) in terms of anticoagulation, platelet activation and lipid metabolism, we selected 54 patients who had been on 4-hour hemodialysis three times weekly for at least 12 months, without bleeding disorders or dyslipidemic diseases. 28 were on hemodialysis with Polysulfone low-flux, 26 were on hemodiafiltration with Polysulfone high-flux. All patients underwent EPO. Methods: During the first 18 months, we administered SH 1,500 IU on starting dialysis and 1,500 ± 500 IU in continuous intradialytic infusion per session. In the following 18 months, we administered LMWH 64.6 IU/kg on starting dialysis in a single arterious bolus. We assessed aPTT, anti-factor Xa activity, TAT and FPA, β-TG and PF4. Blood samples were taken monthly at times 0, 30, 60, 180 and 240 min, as well as 1, 4 and 20 h after dialysis end. Predialysis cholesterol, HDL, LDL, triglycerides and lipoprotein(a) were checked monthly. Results: During both LMWH and SH sessions no clotting or major bleeding complications were observed. APTT with LMWH was lower than that found with SH (p < 0.001); aFXa using LMWH was higher than when using SH (p < 0.001); TAT and FPA were lower in LMWH sessions (p < 0.01) than in SH sessions. We also detected lower β-TG (p < 0.05) and PF4 levels (p < 0.05) using LMWH than using SH. As regards lipids, we only observed a significant decrease in triglycerides after 18 months of LMWH treatment. Conclusions: Routine use of LMWH during hemodialysis affords a safe and effective alternative to SH, and causes reduced platelet activation.

Effect of a New Antithrombotic Agent (Defibrotide) in Acute Renal Failure Due to Thrombotic Microangiopathy

8 patients with thrombotic microangiopathy were treated with a new antithrombotic agent, defibrotide. This drug displays considerable fibrinolytic and antithrombotic activity, and induces generation and release of a prostacyclin-like substance from vascular tissue. At admission all patients presented severe renal involvement and coagulation abnormalities. Neurological manifestations were present in 6. Defibrotide administration was followed by recovery of renal function in 6, disappearance of neurological symptoms and coagulation abnormalities in all patients. The use of defibrotide was not associated with side effects. On the basis of the results obtained in these patients, we suggest that defibrotide might be considered as a valuable drug in the management of patients with thrombotic microangiopathy.

Posttraumatic Chyluria Due to Lymphorenal Fistula Regressed after Somatostatin Therapy

A sudden-onset chyluria after trauma was evaluated giving evidence of a lymphatic-urinary fistula in the right kidney. Treatment with somatostatin normalized the urinary pattern and the result was maintained even after the discontinuation of the therapy.

Validity of flow cytometry for cross-match evaluation in clinical renal transplantation.

This paper reports a 2-year experience of more than 5,000 cross-match tests for renal transplantation. Tests were performed by means of both standard light microscopy and an innovatory method based on flow cytometry, an up-to-date investigative technique for computerized analysis of individual cell characteristics. Flow cytometry allowed a better detection of weak positive reactions (false-negative cross-matches) than light microscopy, thus reducing the risk of selecting candidates with donor presensitization. Transplant clinical outcome supported the value of this original and advanced technological method.

Normalization of Renal Function and Blood Pressure after Dissolution with Intra-Arterial Fibrinolytics of a Massive Renal Artery Embolism to a Solitary Functioning Kidney

The intra-arterial administration of fibrinolytics in a massive embolism to the renal artery of a solitary functioning kidney determined quick normalization of the severe renal failure and hypertension.

Severe gastrointestinal bleeding in a uremic patient treated with estrogen-progesterone therapy.

Gastrointestinal bleeding is a frequent complication in hemodialysis patients; angiodysplasia is a potential cause, with a higher incidence in uremic patients. We describe a case of severe anemia (Hemoglobin up to 3.5 g/dl) secondary to diffuse angiodysplastic lesions in a hemodialysis patient with mixed connective tissue disease. The case is characterised both by the severity of the clinical picture (extension and entity of angiodysplastic lesions, frequency of bleeding episodes) and by the patients religious faith which made her reject blood transfusions. We underline the efficacy of estrogen-progesterone therapy in view of the modest results obtained with other therapeutic strategies on bleeding.

Flow cytometry evaluation of urinary sediment in renal transplantation

The value of exfoliative urinary cytology for the diagnosis of different pathological conditions in renal transplantation is widely recognized. The method, however, has not yet gained full acceptance, mainly because identification of the different cells is not always possible by means of standard staining techniques. In view of its characteristics, flow cytometry (FC) seems to represent a consistently reliable, rapid and innovative approach for differentialing the various cells present in the urinary sediment and assessing their number. This study gives the examination result of 223 urinary specimens from 127 transplanted patients selected according to pathology. Sediment cells, collected from fresh urine samples, were washed, treated with a lysing solution, resuspended in saline solution and directly analysed in a FACSCAN cytometer. Morphological evaluation showed: a small number of cells in patients with stable renal function; a larger number of cells, with predominance of lymphocytes, during acute rejection episodes; an absolute predominance of neutrophils during bacterial infection; large-sized cellular debris in cases of post-transplant tubular necrosis; and small cell debris in cases of cyclosporine cytotoxicity. Lymphocyte surface-marker evaluation made it possible to differentiate lymphocyte populations observed during acute rejection episodes (cytotoxic T-cell, CD8 and HLA class II and NK cells) from those detected during bacterial infection (T-cell CD4 positive). These results suggest that urinary FC may be a reliable diagnostic tool in clinical renal transplantation.

Jugular vein-mammary artery fistula after catheterism for hemodialysis: case report.

The demographic characteristics of hemodialysis (HD) patients increase the need for the tunneled cuffed permanent catheter (TCC) as a definitive vascular access (VA) for HD. The internal jugular vein is increasingly being used as a route for TCC or temporary catheter placement and can be associated with serious complications. Among them other authors have described arteriovenous fistula (AVF) creation between the common carotid artery and the right jugular vein. We describe a case of an AVF between the right internal jugular vein and the right internal mammary artery. The fistula was detected during the TCC placement in a patient who underwent several jugular and subclavian catheterisms for HD in her clinical history.

Renal Arterial Stenosis in Renal Transplantation: A Mathematical Pathogenetic Hypothesis and Its Possible Clinical Implications

The pathogenesis of the renal artery stenosis in renal transplantation is not yet completely clear. A possible role may be played by the impaired progression of the sphigmic wave and of the blood pulse at the point of the vascular anastomosis, caused by an anastomosis between two artery segments with different straining characteristics (1).

Artificial Kidney: Status of the Art and New Perspectives

Extracorporeal dialysis was first performed in 1943 and has become a routine for End Stage Renal Patients from the early sixties. In the last 30 years researchers have focused on biocompatibility of artificial materials and optimisation of removal of uremic toxins by the membrane as in the long term treatment many complications like amylodosis heart and bone lesions, accelerated amyloidosis and immune system failure can occur. From this point of view high flux dialytic membranes are currently considered more biocompatible therefore being able to prevent such diseases.