[A closed cycle]. / Un ciclo chiuso.

A young girl was admitted to the Renal Unit of our Hospital because of loin pain and mild renal failure with bilateral hydronephrosis. The abdomen ultrasound was very helpful to get the right diagnosis.

[Twinkling artifact in kidney stone disease]. / Arlecchino e la calcolosi urinaria.

BACKGROUND: Ultrasonography artifacts are false representations of the image caused by the interaction between the ultrasound and the tissues. The ability to identify artifacts is an important source of information that can help the clinician in performing a correct diagnosis. The twinkling artifact (called 'Effetto Arlecchino' by the Italians) consists of a series of colored pixels that appear inside, around and often along the shadow cone of the calculi. METHODS: We evaluated the clinical effectiveness of this artifact in the diagnosis of kidney stone disease. In 107 ultrasonography cases of hyperechogenic formations with clinical features of kidney stones, we used the color box to evoke the twinkling artifact. Of the 107 cases, 102 cases (95%) presented this artifact, while five cases did not. Moreover, this artifact was present in all urethral and bladder stones and in 62/67 kidney stone cases. CONCLUSIONS: In our experience, we found that the twinkling artifact is often positive in urinary stone disease, and the ability to identify it adds useful information to the diagnosis of urinary kidney stone disease.

The management of hemodialysis arteriovenous fistulas in well functioning renal transplanted patients: many doubts, few certainties.

UNLABELLED: Vascular access (VA) for hemodialysis (HD) is one of the most important clinical problems in end-stage renal disease (ESRD) patients because it can limit a life support system and can influence long-term dialysis patient survival. Nevertheless, VA becomes useless after a successful renal transplant. Therefore, we wanted to evaluate the natural history of arteriovenous fistulas (AVF) in renal transplanted patients and the possibility of maintaining the fistula as patent or not. METHODS: A retrospective study was conducted to evaluate kidney transplant patients in our unit from April 1994 to April 2004. We studied 542 patients. RESULTS: There were 365 patients with a well functioning kidney. Eighty-six patients died. Ninety-one patients were put back on dialysis: 89 patients on HD and two patients on CAPD. Of the 365 patients with functioning kidney transplants, 198 patients demonstrated a patent fistula, while 167 patients had a closed fistula. One hundred and twenty-five patients had a spontaneous closure and 42 patients had a surgical closure. Of the 89 patients put back on dialysis, 49 patients used the previous AVF, while it was necessary to create a new VA in 40 patients. CONCLUSIONS: As demonstrated by the results of our study, after renal transplantation the possibility of spontaneous AVF closure caused by a thrombosis is not a rare event. The dilemma is whether to preserve a fistula that could be useful in case of restarting HD or to perform a systematic fistula closure because of cardiac output and cardiac failure risks. Concerning this question there is no consensus between different authors in the literature. In reviewing the literature and analyzing our data, we conclude that the definite indications for AVF closure in well functioning renal transplanted patients are heart failure, high flow fistula, VA complications and important aesthetic reasons. Routine AVF closure is not indicated until prospective and randomized studies can demonstrate the ability of this procedure to reduce the high incidence of cardiac morbidity and mortality that is present, even after renal transplantation.

Which kind of vascular access for hemodialysis in pediatric patients?

The choice of vascular access in hemodialysis pediatric patients can be challenging, due to the small diameter of vessels. In the last 19 years, 38 arteriovenous fistulas (AVF) for hemodialysis have been created on 21 patients; 25 of them were radio-cephalic AVF. The evaluation of the vessels was, in the majority of cases, done by clinical criteria. A local anesthesia was used in all surgical procedures. The percentage of early AVF failure was 24%. Long-term AVF survival was 97%, 65% and 55% at respectively 1, 3 and 5 years. Our data indicate that even in pediatric patients the radio-cephalic fistula is the first choice surgical procedure.

[Temporary vascular access for haemodialysis: is infection still the most important complication?]. / L'accesso vascolare temporaneo per emodialisi: e' ancora l'infezione la complicanza da temere maggiormente?

BACKGROUND: Aging in the dialitic population currently shows the problem of vascular access for haemodialysis. The use of temporary catheters for haemodialysis has increased the risk of infections. DOQI guidelines underline this problem. We think that the thrombosis of central veins is a problem as important as infection. METHODS: In the last two years we studied prospectively 310 patients. 686 catheters for haemodialysis were placed. Infection, malfunctioning of catheters and thrombosis of central veins were studied. We compared femoral catheters with jugular catheters. Finally we studied by ultrasound the jugular vessels diameter and thrombi of jugular vein. RESULTS. Fever was present in 5.55% of patients with femoral catheters and in 5.84% of the patients with jugular catheters. The malfunctioning incidence in patients with femoral catheters was 22.75% and 8.76% in patients with jugular catheters with statistic difference. Ultrasound study of jugular veins showed thrombotic incidence of internal jugular vein in 20,8% of patients. CONCLUSIONS: We think that with correct management of catheters there is no difference in the incidence of fever in patients with jugular catheters versus femoral catheters. Probably jugular catheters have better performance than femoral catheters. We need controlled studies to better understand the problem of central vein thrombosis.

Internal jugular vein thrombosis after positioning CVC in dialysis patients: The most common ultrasound patterns.

Frequently patients are started on hemodialysis after the placement of a central venous catheter (temporary or tunneled) in the internal jugular vein (IJV). Currenty this procedure is facilitated by ultrasound probes that improve the rate of success of catheter placement in vessels and diminishes the possible complications, minimizing the gap between nephrologists with wide surgical expertise and those with limited surgical experience. Stenosis and thrombosis of the subclavia vein are well documented complications derived from the placement of the venous catheter. Internal jugular vein thrombosis is not seen very often due to scarce clinical evidence. In our paper we have been able to systematically document various extrinsic thrombotic complications outside the central venous catheter, by use of ultrasound (periluminar or related to the vessel).

Acute renal failure after massive ingestion of gliclazide in a suicide attempt.

Gliclazide, a sulfonlyurea class molecule, is used to control glycaemic levels in non-insulin-dependent diabetes mellitus. Acute and chronic toxicity studies, conducted in various animal species, have demonstrated a very low toxicity. We report a patient who developed acute renal failure due to acute tubular necrosis following a massive ingestion of gliclazide in an suicide attempt. The patient ingested 28 grams of gliclazide; the normal dose of gliclazide is 80 mg one or twice a day. At admission the patient was hypoglycaemia and in a few days became oliguric with an increase in the serum creatinine concentration, but with a normal blood urea nitrogen level. He underwent dialysis and ten days after ingestion of gliclazide, his renal function improved rapidly.