Primary intraoperative transluminal angioplasty: a new approach to reduce the early failure of distal arteriovenous fistulas.

PURPOSE: About 8 years ago, we approached an intraoperative transluminal angioplasty (ITA) performed during the arteriovenous fistula (AVF) creation, to treat arterial or venous stenosis diagnosed by a preliminary ultrasound examination. Objective of this study is to validate the efficacy of ITA. METHODS: Early failure (EF) and failure to mature (FTM) were evaluated in 69 AVFs with ITA created in 58 patients in the last 3 years. In the same period, 160 patients received 188 AVFs without ITA and were considered control group. Of the two groups, age, comorbid factors, sex, primary and secondary patency rate (PR) were also analysed. RESULTS: The two groups were homogeneous for gender and age (70.4 + 11.1 years of ITA group vs. 66.3 + 14.4, p = 0.059). The incidence of diabetes, heart disease and peripheral artery disease was higher in the ITA group (43% vs. 17%, p<0.0001, 35% vs. 6%, p<0.0001 and 56% vs. 15%, p<0.0001, respectively). EF and FTM occurred in seven and eight cases in the ITA group and in 15 and 13 cases in the controls, respectively. Total failure occurred in 24% of ITA group and 14% of the controls (p = 0.2). The primary PR at 6, 12 and 24 months was 78%, 72% and 59% for ITA group and 85%, 78% and 78 % for control group (p<0.01). The secondary PR at 6, 12 and 24 months was 91%, 86% and 80% for ITA group and 95%, 95% and 92% for the controls (p<0.01). CONCLUSIONS: Our ITA approach has allowed satisfactory results in patients at a high risk of AVF failure.

[A case of Xanthinuria in a patient with marked hypouricemia]. / Un caso di xantinuria in una paziente con marcata ipouricemia.

Xanthinuria is a rare autosomal recessive disorder associated with a deficiency of xanthine oxidoreductase (XOR), which normally catalyzes the conversion of hypoxanthine to uric acid. The effects of this deficit are an elevated concentration of hypoxanthine and xanthine in the blood and urine, hypouricemia, and hypouricuria. The deficit in XOR can be isolated (type I xanthinuria) or associated with a deficit in aldehyde oxidase (type II xanthinuria) and sulfite oxidase (type III xanthinuria). While the first two variants have a benign course, are often asymptomatic (20%), and clinically indistinguishable, type III xanthinuria is a harmful form that leads to infant death due to neurological damage. The clinical symptoms (kidney stones, CKD, muscle and joint pain, peptic ulcer) are the result of the accumulation of xanthine, which is highly insoluble, in the body fluids. We describe a case of type I xanthinuria in a 52-year-old woman who presented with hypouricemia, hypouricuria and kidney stones. The diagnosis was based on purine catabolite levels in urine and serum measured by 3 nonroutine methods: high-pressure liquid chromatography, mass spectrometry, and magnetic resonance imaging. To identify the type of xanthinuria the allopurinol test was used. We believe that these tests will facilitate the diagnosis of xantinuria especially in asymptomatic patients without the need for a biopsy of the liver or intestines, which is useful only for scientific purposes.