Predictor factors for renal outcome in renal artery stenosis

BACKGROUND

Atherosclerotic ischemic renal disease is a frequent cause of end-stage renal failure. Correction of renal artery stenosis (RAS) may fail to stabilize or improve renal function.

AIMS OF THE STUDY

Carotid and aortic Intima media thickness (IMT), resistance renal resistance index (RI), arterial blood pressure (BP), serum creatinine (SCr), creatinine clearance (CrCl), proteinuria and uricemia were considered as possible predictive factors and measured before renal-artery stenosis correction and during 12 months follow-up.

MATERIALS AND METHODS

we performed an observational study on a total of 55 patients to find predictive factors of the outcome of renal function after renal percutaneous transluminal angioplasty and stenting (RPTAs).

RESULTS

We found that uricemia, proteinuria and IR were higher at baseline in patients who worsened renal function after revascularization.

CONCLUSIONS

The identification of predictive factors (uricemia; proteinuria and RI) of chronic kidney disease (CKD) progression in patients with RAS undergone revascularization could be useful to predict renal long term outcome and to select patients that really could benefit of this.

Primary stenting for renal fibromuscular-dysplastic stenosis: a case report

Fibromuscular dysplasia (FMD) is a non-inflammatory, non-atherosclerotic vascular disease that has been reported in renal and internal carotid arteries and in almost every arterial bed, primarily affecting young to middle-aged people, mainly female individuals. These patients may be asymptomatic or may present with hypertension. A 29 year-old hypertensive woman was referred for a renal color Doppler ultrasound (CDU) scan because of a suspicion of renovascular hypertension and we revealed the presence of three separate stenosis on the right renal artery. Digital selective angiography (DSA) and percutaneous transluminal angioplasty (PTA) were performed but an incomplete dilation of the vessel was obtained. Because of the suboptimal result, it was decided to stent the lesions during two different procedures. Percutaneous transluminal renal angioplasty is the primary treatment of renal FMD, but should not be excluded primary stent implantation as an alternative technique to surgical revascularization.

Plasma levels of adrenomedullin, a vasoactive peptide, in type 2 diabetic patients with and without retinopathy

AIM

The aim of this study was to investigate whether adrenomedullin (AM) secretion is modified in type 2 diabetic patients with and without retinopathy.

METHODS

The study was performed on 92 patients with type 2 diabetes, 65 of whom had uncomplicated diabetes, 27 had retinopathy, and 40 had mild to moderate hypertension. Patients with serum creatinine levels >1.2 mg/dL, were excluded. Circulating AM was assayed using a specific radioimmunoassay.

RESULTS

AM concentrations were significantly higher in type 2 diabetic patients (25+/-2.1 pg/mL) than in the 31 normal subjects (11+/-0.8 pg/mL) (P<0.001). Type 2 diabetic patients with retinopathy had significantly greater AM levels (30.8+/-3.4 pg/mL) than both controls (P<0.001) and type 2 diabetic patients without retinopathy (25.2+/-2 pg/mL same as previous value) (P<0.001). No statistical difference was found between diabetic patients with pre-proliferative retinopathy (27.3+/-4.7 pg/mL) and proliferative retinopathy (24+/-3.1 pg/mL) (P=0.543). In type 2 diabetic patients, a significant correlation between plasma AM levels and HbA1c values (r=0.467; P<0.01) was found.

CONCLUSION

Our findings indicate that circulating AM is increased in type 2 diabetic patients and that increase correlates with poor glucose metabolic control and presence of retinopathy.

Diagnosis and outcome of renal function in patients with renal artery stenosis: which role have color Doppler sonography and magnetic resonance angiography?

AIM

Minimally invasive diagnostic techniques would be useful in the preoperative diagnosis of patients with hypertension and ischemic renal disease. The aim of our study was to compare color Doppler sonography (CDS), and magnetic resonance angiography (MRA) with the reference standard, digital subtraction angiography (DSA), in the diagnosis of renal artery stenosis.

METHODS

Thirty-nine patients with arterial hypertension and monolateral or bilateral renal artery stenosis documented by CDS underwent renal artery MRA and then DSA during corrective percutaneous transluminal angioplasty. CDS and MRA scans were evaluated by 3 independent observers who studied 78 main renal arteries. Stenosis of 70% or more were regarded as significant. Sensitivity, specificity, positive and negative predictive values and two-sided 95% confidence intervals of CDS and MRA for the detection of significant renal artery stenosis were calculated. The statistical significance of the differences in sensitivities between CDS and MRA was assessed by means of the kappa test (< or =1).

RESULTS

CDS and MRA, therefore, both achieved 97.6% sensitivity and 100% specificity for diagnosing stenoses at the origin of the renal artery; CDS yielded 100% sensitivity and 97.1% specificity and MRA 87.5% sensitivity and 98.6% specificity for diagnosing stenosis in the intermediate distal segments.

CONCLUSIONS

Statistically significant differences between CDS and MRA in the diagnosis of renal artery stenosis have not been observed. However, according to our experience, CDS is the preferred technique because it also provides useful information about the development of kidney disease before correction.

Suprarenal artery stenosis may be mistaken for renal artery stenosis in Doppler studies

There are several limitations in using colour-flow-Doppler (CFD) to diagnose renal artery stenosis. This report describes a case of "false positive" stenosis of the renal artery diagnosed using CFD. A patient affected by arterial hypertension and with a suspected stenosis of the renal artery was examined using CFD. However, the patient was in fact suffering from suprarenal artery stenosis.