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.

Could an echo contrast agent be helpful in identifying renal artery stenosis?

BACKGROUND: Diagnosis of renal artery stenosis using echo color-Doppler is subjected to several limitations. The aim of this study was to examine if the routine use of a contrast agent could be helpful in identifying renal artery stenosis (RAS). METHODS: We analysed 35 patients affected by RAS using an echo color-Doppler coupled with a contrast agent. All patients presented arterial hypertension, with a good drugs control, and mean serum creatinine of 1.8 mg/dL. All patients previously underwent angiography. RAS was at the origin of the artery in 27 patients, at the intermediate tract in 8. All patients had already been submitted to a basal echo color-Doppler. RESULTS: The contrast agent determined a significant increase in the average colour signal in all the subjects, and a better evaluation of the spectral waveforms, if compared to the basal examination. CONCLUSIONS: The results obtained showed that the contrast agent doesn't improve the diagnosis of RAS, especially in vascular origin stenosis, while it shows a real advantage in the intermediate or distal stenosis which are better visualized.

[Comparison of 0.125% bupivacaine and 0.2% ropivacaine in obstetric analgesia]. / Confronto tra bupivacaina 0.125% e ropivacaina 0.2% nell'analgesia del parto.

This comparative study of low doses of ropivacaine was conducted in order to identify the most effective form of analgesia during labour with the aid of supplementary low doses of fentanyl and clonidine. 60 ASA I and II parturient primipares who had asked for epidural analgesia were randomly assigned to two groups. Group R was given 5-7 ml 0.2% ropivacaine and Group B 0.125% bupivacaine with both groups receiving 75 ng clonidine and 50 ng fentanyl with their first bolus of local anaesthetic. The parameters measured included the speed and spread of the sensory blockade and the scale of any motor blockade. The material haemodynamics and VAS pain relief scores were also measured at 30-minute intervals during labour and all side-effects (nausea, vomiting, localised or generalised itching, headache etc) were also monitored. Apgar anaesthetics and other drugs was decided on the basis of the VAS score (a further dose was given to women with a VAS of > 3-4). The study was completed by a telephone interview 6 months after delivery and the data were analysed using the Student's t-test and the chi 2 test. The analgesic effect was satisfactory in both groups and no statistically significant differences were found between the two groups under most of the headings analysed, apart from the top-up doses needed to maintain adequate analgesia. The average time between the first VAS to parturition was 292 mns in Group B and 267 mns in Groups R. Top-up doses of local anaesthetic (2.35 vs 5.05) came on average to 15.8 ml in Group B compared to 24.1 ml in Group R. There were 20% Caesarian sections in Group R and 13.8% in Group B. Optimum analgesia was achieved in Group R, the level of analgesia was insufficient or barely sufficient in 3.3% of cases. There was no Apgar score < 7 in either group. It was therefore concluded that both bupivacaine and ropivacaine offer excellent analgesia during labour and have no significant side effects on mothers or babies.

Color-Doppler sonography in ophthalmology.

BACKGROUND: With the present study we considered ocular blood flow by the use of color Doppler ultrasound. We compared the most clinically important arteries of both eyes. We valued the central retinal artery, the posterior long ciliary arteries, the posterior brief ciliary arteries and the central retinal vein. METHODS: We submitted to an ecd examination of the ophthalmic arteries 50 patients, of whom 30 were healthy, 4 presented a pallor of the optic disk, 6 were affected by chronic simple glaucoma and 10 were affected by arterial hypertension. RESULTS: This study has allowed us to define the normal and pathologic anatomic findings at the ecd tracing therefore qualitative and quantitative standards of this examination, repeatable and comparable. CONCLUSIONS: Currently the different techniques used to study ocular blood flow, do not allow its exact detection, but only a morphological evaluation of the eye artero-venous system. Acquisition of morphological and velocimetric data, at the same time, allows a more exact evaluation of the pathology. Therefore the ecd is a simple rapid and non-invasive approach, useful in the acquisition of important data concerning diagnostic confirmation, prognosis, and above all pharmacological follow-up of many pathologies such as diabetes, glaucoma and arterial hypertension. The diagnosed vascular alterations are correlated to the degree retinopathy and to the effectiveness of the pharmacological treatment.

[Penile ultrasonography. Characteristic velocimetric feature in the maximal erection phase in healthy subjects]. / Eco color-Doppler penieno. Caratteristico aspetto velocimetrico nella fase di massima erezione in soggetti sani.

BACKGROUND: A peculiar finding from penis eco color-Doppler, detected in healty subjects with erection dysfunction, is described. METHODS: 385 patients with erection dysfunction were studied, by using duplex scan with color Doppler, 85 of these patients normal Regiscan test were chosen and patients with Induratio penis plastica or hormonal disorder were excluded. RESULTS: A "reverse" flow during the entire diastolic phase was detected in 58 normal patients (68%) with age < of 41 years. CONCLUSIONS: In the evaluation of healthy subjects with erection dysfunction, the presence of a complete "reverse" diastolic flow is indicative of a venous reflux block, that may represent an important pathogenetic mechanism in this specific setting.

Poroelastic finite element analysis of a bone specimen under cyclic loading.

It had been suggested that the fluid embodied in bone lacunar-canalicular porosity may play an important role in bone remodelling [Weinbaum et al., 1994. Journal of Biomechanics 27, 339-360]. In this paper a finite element model of a poroelastic prismatic solid of rectangular cross-section is considered to simulate bone behaviour, precisely as in the previous work by Zhang and Cowin [Zhang and Cowin, 1994. Journal of Mechanical Physics of Solids 42, 1575-1599]. This solid is subject to combined cyclic axial and bending loads at its end. The objectives of the study are: (1) to verify the accuracy of the simplifying hypotheses underlying the analytical solutions established by the above authors; (2) to provide further insight into the behaviour of that solid; (3) to test the advantages in generality and versatility and the computing costs of general-purpose finite element codes in poroelastic analysis. The study is parametric with respect to the fluid leakage coefficient, to the ratio of the bending moment and axial load, and to the ratio of the characteristic relaxation time of the pore pressure over the excitation period. Results show that, for all the cases considered, the pore pressure distribution along the section height of the poroelastic beam exhibits a very good matching with previous analytical results. Stresses transversal with respect to the beam axis (assumed as constant or zero in previous analytical solutions) are evaluated. The analysis pointed out that: (1) the effects due to end-loads with zero resultants practically extinguish within a distance from the beam end almost equal to a typical length of the cross-section; (2) cross-sections remain plane above that distance; (3) the transversal total stresses are three orders of magnitude lower than axial stress.

Antineutrophil cytoplasmic antibodies in autoimmune thyroid disorders.

Different antibodies against both organ- and non-organ-specific autoantigens have been found in patients with autoimmune thyroid diseases. The aim of our study was to evaluate the presence of antineutrophil cytoplasmic antibodies (ANCA) in sera of patients affected by Graves' disease (GD) and Hashimoto's thyroiditis (HT). These antibodies were investigated by indirect immunofluorescence; the reactivity against myeloperoxidase and lactoferrin was assessed by ELISA. ANCA were detected by immunofluorescence in 28.5% of patients with GD and 9% of patients with HT. Anti-lactoferrin antibodies were found in 3 of 21 (14.2%) patients affected by GD and in 2 of 11 (18.1%) cases of HT. Anti-myeloperoxidase antibodies were detected only in one (4.7%) patient with GD.

Vascular endothelial growth factor: a key mediator of neoangiogenesis. A review.

Vascular endothelial growth factor (VEGF) is a multifunctional cytokine that exerts in vivo a key role in physiological and pathological neoangiogenesis by stimulating endothelial cell proliferation and vessel hyperpermeability. VEGF exists as one of four different isoforms, respectively, VEGF 121, VEGF 165, VEGF 189, VEGF 206, and seems to be a crucial mediator of physiological neoangiogenesis during the embryonic development and the female cycle. VEGF also has a major role in the pathogenesis of many diseases including hypervascularized tumors, rheumatoid arthritis, cutaneous diseases and proliferative retinopathies. Anti-VEGF anti-bodies or VEGF agonists may represent a novel approach in the treatment of these diseases.

[Indirect diagnosis of aortic coarctation by Doppler color echography. Velocimetric and spectral aspects in one of our cases]. / Diagnosi indiretta di coartazione aortica mediante eco color-Doppler. Aspetti velocimetrici e spettrali in un caso di nostra osservazione.

OBJECTIVE: Description of a case report. PATIENTS: The case of a 55-years-old man with a previous history of hypertension, treated for several years with many antihypertensive drugs without improvement is described. RESULTS: The patient was affected with a unknown coarctation of the aorta. This disease, in fact, is an important cause of secondary hypertension. Adult patients, if asymptomatic, are most often diagnosed because of hypertension or murmur on a routine examination. This congenital disease can be demonstrated on suprasternal notch two-dimensional echocardiographic views along with increased Doppler flow velocity across the coarctation site. TC scan and aortography confirm the degree and nature of the aortic narrowing. CONCLUSIONS: In the case reported color Doppler ultrasonography demonstrated two peculiar aspects of the coarctation of the aorta: 1) detection of a stenotic flow in the abdominal aorta, abdominal and lower extremities arteries; 2) marked renal vasodilatation secondary to compensatory mechanisms that intervene in the renal flow reduction; this finding is detectable in the presence of bilateral stenosis of renal arteries as well as in the hypertensive forms of coarctation of the aorta.