[Steno-obstructions of haemodialytic FAV: new aspects of endovascular treatments]. / Trattamento endovascolare delle complicanze steno-ostruttive delle fistole artero-venose emodialitiche: nuovi aspetti di intervento con radiologia interventistica.

Angioplasty is the usual method for the treatment of stenosis of arteriovenous fistulas for hemodialysis, along with fibrinolysis and thrombus aspiration. We evaluated the efficacy and safety of interventional radiology procedures in the treatment of stenosis or occlusion of arteriovenous fistulas. One hundred thirteen patients suffering from malfunction of arteriovenous fistulas underwent interventional radiological procedures (140 treatments). In all patients color-Doppler was performed beforehand. Stenosis at the site of the fistula was found in all patients and was treated with percutaneous transluminal angioplasty (PTA); stenosis at the anastomosis site was found in 63 cases and was treated by angioplasty with a microcatheter. In 40 patients suffering from recent thrombotic occlusion, locoregional thrombolysis and PTA were necessary. Technical and clinical success was achieved in 107 patients (94.6%); in 1 of 6 unsuccessful treatments the procedure had to be interrupted due to the rupture of a vein. Follow-up exams demonstrated primary patency in 92.5%, 71.9% and 49.5% of patients at 6 months, 1 year and 2 years, respectively. In 19 patients (17.7%) hemodynamically significant restenosis was observed, which was treated with multiple PTAs (27 treatments, only 1 of which with a negative outcome), resulting in a 94.2% success rate; only 1 patient had to undergo a fourth PTA. The overall patency rate was 95%, 87.2%, 62.3% at 6 months, 1 year and 2 years, respectively. In our experience immediate success and excellent patency rates were observed, which persisted in the medium and long term. PTA, with thrombolysis and thromboaspiration, is the treatment of choice in cases of malfunctioning arteriovenous fistulas. PTA should always be attempted before making a new surgical access in order to preserve the vascular tree.

Impaired glucose oxidation and glucose-induced thermogenesis in renal transplant recipients.

BACKGROUND: Renal transplant recipients often show various metabolic abnormalities including reduced glucose tolerance, impaired insulin sensitivity and altered lipid metabolism. However, the acute effects of carbohydrate ingestion on substrate utilization and energy expenditure have not been fully elucidated. METHODS: We evaluated: (i) basal energy expenditure (EE) and substrate utilization, (ii) metabolic fate of an oral glucose load, and (iii) substrate-induced thermogenesis in: (a) 15 non-diabetic renal transplant recipients (Tx) (BMI 25+/-1) on triple immunosuppressive therapy, (b) 11 patients with primary glomerulonephritis (BMI 25+/-1) (Cort) receiving prednisone treatment, and (c) 12 healthy subjects (BMI 26+/-1) (N). Continuous indirect calorimetry was performed in the basal post-absorptive state for 60 min and continued for an additional 180 min following an oral glucose load (75 g). RESULTS: In the basal state, EE was similar in the three study groups. It averaged 14.6+/-0.7, 15.7+/-1.3, and 14.1+/-0.8 cal/kg/min in Tx, Cort, and N respectively. Glucose oxidation was higher in N (1.3+/- 0.2 mg/kg/min) than in Tx (0.7+/-0.2) and Cort (1.0+/-0.2) (P<0.05 in N vs. Tx and vs. Cort), whereas lipid oxidation was lower in N (0.6+/-0.1 mg/kg/min) than in Tx (0.9+/-0.1) and Cort (0.9+/-0.05) (P<0.03 in N vs. Tx and vs. Cort). After glucose ingestion, total carbohydrate oxidation averaged 21.2+/-2, 31.0+/-3, and 29.6+/-3 g, which represented 28+/-3, 41+/-3 and 39+/-2% of the total glucose load in Tx, Cort and N respectively (P<0.01 Tx vs Cort and N). The cumulative increase of EE (180 min) was 9.7+/-2, 13.2+/-3 and 13+/-3 kcal in Tx, Cort, and N respectively. CONCLUSIONS: The present data show that in non-diabetic renal transplant recipients basal EE is normal. However, basal lipid oxidation is higher and glucose oxidation is lower than in healthy subjects. In addition, the oxidative disposal of a glucose load and substrate-induced thermogenesis are impaired.

A case of transient blindness in a postoperative hyponatremic child.

Hyponatremia represents a common electrolyte disorder in postoperative patients. Headache, nausea, emesis, weakness and lethargy are all consistent symptoms of hyponatremia in children. Among the neurologic symptoms that are infrequently seen in severe hyponatremic pediatric patients seizure is included while visual disorders are not. We report a case of an 8-year-old boy who underwent abdominal surgery and developed severe hyponatremia. Five days after surgery the child suffered a seizure and successively experienced bilateral visual loss. However, after prompt correction of serum sodium concentration, a complete resolution of the blindness was obtained. Thus, we discuss the present case speculating on the pathogenesis of hyponatremic blindness and on its possible therapeutic approach. In conclusion, we suggest that blindness is to be considered a rare symptom that can occur in the clinical scenario of hyponatremia and we report its complete reversibility after timely treatment of hyponatremia.

Increased urinary albumin excretion is a marker of risk for retinopathy and coronary heart disease in patients with type 2 diabetes mellitus.

The prevalence of increased urinary albumin excretion (UAE) (micro- and macroalbuminuria) and its association with diabetic retinopathy (DR) (evaluated by fluorescent angiography), coronary heart disease (CHD), and various related risk factors were studied in 320 type 2 diabetic patients. In this subsample of type 2 diabetic patients, microalbuminuria was present in 15% of the patients; macroalbuminuria in 4.8%, CHD in 9.9%, DR in 53.4%, and arterial hypertension in 46%. UAE was independently related to CHD (P < 0.05), retinopathy (P < 0.001), hypertension (P < 0.001), and triglycerides (P < 0.02). We conclude that increased UAE is associated to a greater frequency of retinopathy and CHD in type 2 diabetic patients.

Microalbuminuria and severity of diabetic retinopathy in type 1 diabetic patients: association and relationship with some risk factors.

To investigate the relationship between microalbuminuria and severity of retinal damage, we studied 86 Albustix-negative insulin-dependent diabetic patients whose disease duration was more than 5 years (age 31.9 +/- 10.9 years; duration 14.7 +/- 7.1 years). Retinopathy was evaluated by fluorescein angiography in four groups of patients: a) 37 (43%) without retinopathy, b) 29 (34%) with background retinopathy, c) 10 (12%) with pre-proliferative retinopathy and d) 10 (12%) with proliferative retinopathy. Microalbuminuria (urinary albumin excretion > 30 mg/24 h) was calculated from timed 24-h urine collection and measured by a radioimmunoassay method. Microalbuminuria was found in 20 patients (23%); 16 of whom showed both retinopathy and microalbuminuria. Diabetic retinopathy was more frequent than microalbuminuria (57% vs 23%). The prevalence of microalbuminuria was significantly higher in the proliferative retinopathy group compared to the group without retinopathy (p < 0.0005) and the background retinopathy group (p < 0.007). The frequency of diabetic retinopathy was significantly higher (p < 0.04) in patients with than without microalbuminuria. These results indicate that microalbuminuria is associated with the presence and severity of diabetic retinopathy in insulin-dependent diabetic patients.