Nitinol stents with polymer-free paclitaxel coating for stenosis of failing infrainguinal bypass grafts.

AIM: This study was designed to investigate the immediate and one-year outcomes of polymer-free paclitaxel coated drug-eluting stent (DES) implantation in a consecutive series of patients presenting with stenosis of infrainguinal bypass grafts. METHODS: Between January 2011 and January 2012, 11 patients with failing infrainguinal bypass grafts were treated in two institutions. Clinical status and Duplex scan parameters were recorded at baseline and over a follow-up period of one year. RESULTS: DES implantation was successfully performed in all patients. Ten patients received a single stent and one patient received two stents. At one year, one patient showed total bypass graft occlusion (9%). In all the remaining patients, Duplex scan examination documented patency of the treated grafts. CONCLUSION: DES implantation in failing infrainguinal bypass grafts can be safely performed and provides satisfactory clinical outcomes. The patency rate of 91% favourably compares with those obtained with other endovascular treatments such as plain balloon or cutting balloon angioplasty.

Bailout directional atherectomy for side branch salvage following subintimal recanalization of infragenicular arteries.

A 64-year old diabetic male presenting with critical limb ischemia was treated with percutaneous angioplasty for occlusion of the infragenicular popliteal artery and crural vessels. Directional atherectomy was uncommonly used in the false lumen created by following subintimal angioplasty of the infrapopliteal vessels for re-access into the true lumen. The positive clinical and angiographic results indicate that atherectomy can be considered a useful tool for rescue interventions to reopen large side branches unintentionally occluded during subintimal angioplasty.

Defining a new standard for IVUS optimized drug eluting stent implantation: the PRAVIO study.

OBJECTIVES: Preliminary Investigation to the Angiographic Versus IVUS Optimization Trial is a single center prospective observational intravascular ultrasound (IVUS) guided stent implantation study assessing new criteria for optimal drug eluting stent (DES) deployment. BACKGROUND: IVUS assessment of DES often reveals underexpansion and malapposition. Optimal stent deployment is currently poorly defined and previous criteria may not be suitable in long and complex lesions. METHODS: Optimization was defined as achieving >/or 70% of the cross-sectional area (CSA) of the postdilation balloon. This criterion was applied in 113 complex lesions. The size of this balloon was calculated according to vessel media-to-media diameters at various sites inside the stented segment. The IVUS guided treated lesions were matched according to diabetes, vessel type, reference vessel diameter, minimum lumen diameter (MLD), and lesion length with a group of angiographic treated lesions to compare final MLD achieved. RESULTS: Mean minimum stent CSA according to the postdilation balloon utilized was 4.62 mm(2), 6.26 mm(2), 7.87 mm(2), and 9.87 mm(2) for 2.5 mm, 3.0 mm, 3.5 mm, and 4 mm balloons, respectively. Final MLD (mm) was significantly larger in the IVUS compared to the angiographic-guided group (3.09 +/- 0.50 vs. 2.67 +/- 0.54; P < 0.0001). There were no procedural complications related to IVUS use. CONCLUSIONS: We propose new IVUS criteria based on vessel remodeling that results in an increment in the final MLD, compared to angiographic guidance, which is much larger than any previously published study. This criterion seems to be safely achievable. A proposed randomized study (angiographic vs. IVUS optimization trial) has been launched to test these concepts.

Treatment of bifurcation lesions with two stents: one year angiographic and clinical follow up of crush versus T stenting.

OBJECTIVES: To compare long term outcomes of the crush versus the T technique in bifurcation lesions. DESIGN: 182 consecutive patients were identified who underwent percutaneous coronary interventions for bifurcation lesions with drug eluting stents between April 2002 and January 2004. Two techniques were used according to the operator's discretion: crush (group C, n = 121) or T (group T, n = 61). RESULTS: In-hospital outcome differed significantly between the two groups. Angiographic follow up was available for 142 (78%) patients. Groups C and T did not differ significantly regarding late loss (0.42 (0.39) mm v 0.34 (0.35) mm, p = 0.52) and rate of restenosis (16.2% v 13.0%, p = 0.80) in both the main and the side branch without final kissing balloon post-dilatation. However, when final kissing balloon post-dilatation was performed, group C had significantly lower late lumen loss (0.23 (0.21) mm v 0.37 (0.33) mm, p = 0.02) and restenosis rate (8.6% v 26.5%, p = 0.04) in the side branch. At one year's clinical follow up, group C compared with group T had lower rates of target lesion revascularisation (14.0% v 31.1%, p = 0.01) and target vessel revascularisation (16.5% v 32.8%, p = 0.02). CONCLUSIONS: In non-selected bifurcation lesions treated with drug eluting stents, the restenosis rate remains relatively high in the side branch. Compared with the T stenting technique, crush stenting with kissing balloon post-dilatation is associated with a reduced rate of restenosis in the side branch.

New pharmacological protocols to prevent or reduce contrast media nephropathy.

Contrast media associated acute renal failure represents the third cause of in-hospital renal function deterioration after decreased renal perfusion and post-operative renal insufficiency. Although generally benign, this complication shows a mortality rate ranging from 3.8% to 64%, depending on the increase of creatinine concentration. The mechanism by which contrast-induced renal failure occurs is not well understood. Contrast agent-associated nephrotoxicity appears to be a result of direct contrast induced renal tubular epithelial cell toxicity and renal medullary ischemia. Furthermore, a key mechanism seems to be alteration in renal dynamics, probably caused by imbalances between vasodilator and vasoconstrictor factors, including the activities of nitric oxide, prostaglandins, endothelin and reactive oxygen species. Recommendations to prevent contrast-associated nephrotoxicity are: 1) periprocedural hydration, 2) use of a low osmolality contrast, and 3) limiting the amount of contrast agent. Recently, considerable interest has resulted from the preliminary positive data on the effectiveness of prophylactic administration of antioxidant compounds (such as acetylcysteine and ascorbic acid) and fenoldopam.

Coronary bifurcation stenting. Current techniques, outcome and possible future developments.

Percutaneous treatment of coronary bifurcation lesions remained challenging in the stent era, with restenosis rates greater than 30% and no advantage from the routine use of kissing stents. Drug eluting stents (DES) have dramatically reduced the restenosis rates (RR) in the main vessel, but with conventional T-stenting double digits figures are still reported for the side-branch because of poor ostial coverage. The techniques of kissing stenting able to provide full lesion coverage (Culotte, V-stenting, Crush) have the potential to improve these results but the development of dedicated DES is probably needed to obtain consistently high procedural and long-term success.

The use of drug eluting stents in single and multivessel disease: results from a single centre experience.

OBJECTIVE: Drug eluting stents have been shown to reduce the rate of in-stent restenosis in cases where single lesions are treated. The performance of these stents, in patients with multivessel disease and complex lesions, however, remains unknown. Our experience with sirolimus eluting stents in such patients is presented. DESIGN AND PATIENTS: This study includes all consecutive patients treated at San Raffaele Hospital and EMO Centro Cuore Columbus, Milan, Italy treated with sirolimus eluting stents. RESULTS: Between April 2002 and March 2003, 486 patients with 1027 lesions were treated (437 males, 49 females) with a mean (SD) age of 62.2 (10.5) years. Of all patients studied, 19.1% had single vessel disease, 33.8% had two vessel disease, and 47.1% had three vessel disease. Of the whole study group, 20.3% of patients had diabetes mellitus. A mean (SD) of 2.3 (0.4) stents per patient and 1.1 (0.2) stents per lesion were implanted. The baseline mean reference diameter was 2.7 (0.6) mm with a mean minimal luminal diameter of 0.9 (0.5) mm. Post-stenting, the acute gain was 1.8 (0.6) mm. During hospital stay one patient died (0.2%) and 13 (2.7%) patients had in-hospital myocardial infarction (MI). One patient required urgent repeat percutaneous coronary intervention. Six months clinical follow up was performed in all 347 eligible patients. Six months mortality was 2.0% (n = 7) and acute MI occurred in 0.3% (n = 1). Target lesion revascularisation occurred in 9.5% (n = 33) of the patients and target vessel revascularisation (TVR) in 11.5% (n = 40) of the patients. Major adverse cardiac event rate was 13.8% (n = 48). TVR was 4.5% for single vessel disease and 13.2% for multivessel disease. Diabetes mellitus was the only significant predictor for TVR. CONCLUSION: The use of drug eluting stents in single and multivessel coronary disease produces good short and medium term results with a low rate of revascularisation. Longer term follow-up is required to confirm these observations.

Clinical and angiographic outcome of directional atherectomy followed by stent implantation in de novo lesions located at the ostium of the left anterior descending coronary artery.

BACKGROUND: Lesions located at the ostium of the left anterior descending coronary artery (LAD) are considered an ideal target for directional atherectomy (DCA), but few data are available about the value of using this strategy before stenting in comparison with stenting alone. OBJECTIVES: To investigate the immediate and mid term clinical and angiographic results of DCA followed by stent implantation for ostial LAD lesions. DESIGN: Retrospective comparison of the immediate and mid term angiographic and clinical results of a series of 117 consecutive patients with de novo lesions located at the ostium of the LAD. Of these, 46 underwent DCA before stenting and 71 were treated with stenting alone. RESULTS: Technical success in the two groups was similar at around 98%. DCA plus stenting provided a larger minimum lumen diameter at the end of the procedure than stenting alone (3.57 (0.59) mm v 3.33 (0.49) mm, p = 0.022). There were no differences for in-hospital major adverse events (MACE) (7.5% for atherectomy plus stenting, and 5.3% for stenting alone; p = 0.41). All patients had clinical follow up at a mean of 7.9 (2.7) months. Angiographic follow up was done in 89 patients (76%) at a mean of 5.9 (2.2) months. The atherectomy plus stenting group had a larger minimum lumen diameter than the stenting group (2.79 (0.64) mm v 2.26 (0.85) mm, p = 0.004) and a lower binary restenosis rate (13.8% v 33.3%, p = 0.031). Six month MACE were reduced in the atherectomy plus stenting group (8.7% v 23.9%, p = 0.048). CONCLUSIONS: Debulking before stenting in de novo lesions located at the ostium of the LAD is safe and is associated with a high rate of technical success. Follow up data show that DCA plus stenting results in a significantly larger minimum lumen diameter and a lower incidence of restenosis than stenting alone.

Immediate and long-term clinical and angiographic results from Wiktor stent treatment for true bifurcation narrowings.

From January 1996 to December 1998, 90 consecutive patients with true bifurcation lesions underwent percutaneous coronary angioplasty with Wiktor stent implantation in our centers. In 1 group (group I, n = 45), a simple approach (main vessel stenting and balloon angioplasty of the side branch) was pursued. In the other group (group II, n = 45), both the main vessel and the side branch were stented ("T" technique). There was no significant difference in clinical and angiographic characteristics between the 2 groups. Angiographic and procedural successes were 100% and 95.6%, respectively, in both groups. Angiographic results for the side branch were better in group II than in group I. In-hospital and long-term (12 month) major cardiac events were similar in the 2 groups. Target lesion revascularization was 15.5% in group I and 35.5% in group II (p = 0.12). In the main vessel, restenosis rate was 12.5% in group I and 25% in group II (p = 0.15). In the side branch, restenosis rate was 37.5% in group II and 12.5% in group I (p = <0.05; odds ratio 2.42; 95% confidence interval 1.05 to 6.26). Event-free probability at 12 months was 61% in group II and 80% in group I (p = 0.10). When dealing with true bifurcation lesions, a simple strategy is associated with a lower risk of restenosis in the side branch. In contrast, a complex approach does not appear to give any benefit in terms of early or long-term outcome or restenosis rate.

Usefulness and limits of distal echo-Doppler velocimetric indices for assessing renal hemodynamics in stenotic and non-stenotic kidneys.

BACKGROUND: Distal echo-Doppler velocimetric indices are widely used for revealing the presence of a renal artery stenosis but there is scarce information as to whether they reflect the renal hemodynamics in stenotic and nonstenotic kidneys. OBJECTIVES AND METHODS: We evaluated the pulsatility and resistive indices (PI and RI), acceleration (A) and acceleration time (At) and correlated their values with those of effective renal plasma flow (ERPF), glomerular filtration rate (GFR), renal vascular resistance (RVR) and filtration fraction (FF) estimated by single kidney scintigraphy in 24 kidneys with 70-95% renal artery stenosis (atherosclerotic n = 17, fibromuscular n = 7) and in 27 non-stenotic kidneys (11 contralateral to renal artery stenosis and 16 of patients with essential hypertension). In patients with stenotic kidneys, these measurements were repeated within 7 days after a successful percutaneous transluminal renal angioplasty (PTRA) (in 11 arteries performed in combination with stent implantation). RESULTS: Prior to dilation we found that the stenotic kidneys had significantly lower values of ERPF, GFR and higher RVR than the non-stenotic kidneys and that these hemodynamic alterations were associated with those, also statistically significant, of the four velocimetric indices. In non-stenotic kidneys, there were highly significant relationships between PI and ERPF, and RVR (r = -0.68 and 0.81 respectively P < 0.01); similar relationships were found for RI (r = -0.67 and 0.78 P < 0.01) whereas no such correlations were found between these two velocimetric indices and GFR and FF; also no correlations were found between A and Atand ERPF, GFR, RVR and FF. In stenotic kidneys no significant correlations were found between any of the velocimetric and the hemodynamic indices. Renal artery dilation induced clear cut increments in ERPF, GFR and reduction in RVR in post-stenotic kidneys, which were associated with normalization of all four velocimetric indices. No relationships were observed between the renal hemodynamic and the velocimetric changes induced by dilation; however in post-stenotic kidneys the relationships between PI and RI, ERPF and RVR were restored as in nonstenotic kidneys. CONCLUSIONS: These data indicate that PI and RI can be used to assess ERPF and RVR both in non-stenotic and post-stenotic kidneys; however, none of the velocimetric indices examined in this study can provide valid informations on the renal hemodynamics of stenotic kidneys and on their changes induced by PTRA.

Emergency stenting to treat neurological complications occurring after carotid endarterectomy.

OBJECTIVES: The purpose of this study was to assess the efficacy of emergency stent implantation for the treatment of perioperative stroke after carotid endarterectomy (CEA). BACKGROUND: Carotid endarterectomy has been proven safe and effective in reducing the risk of stroke in symptomatic and asymptomatic patients with >60% carotid artery stenosis. However, perioperative stroke has been reported in 1.5% to 9% of CEA cases. The management of such a complication is challenging. Recently, percutaneous transluminal carotid angioplasty with stent deployment has emerged as a valuable and alternative strategy for the treatment of carotid artery disease. METHODS: Between April 1998 and February 2000, 18 of the 995 patients (1.8%) who had CEA in our institution experienced perioperative major or minor neurological complications. Of these, 13 patients underwent emergency carotid angiogram and eventual stent implantation, whereas the remaining five had surgery re-exploration. RESULTS: Carotid angiogram was performed within 20+/-10 min and revealed vessel flow-limiting dissection (five cases) or thrombosis (eight cases). Percutaneous transluminal carotid angioplasty with direct stenting (self-expandable stent) was performed in all 13 cases. Angiographic success was 100%. Complete remission of neurological symptoms occurred in 11 of the 13 patients treated by stent implantation and in one of the five patients treated by surgical re-exploration (p = 0.024). CONCLUSIONS: Stent implantation seems to be a safe and effective strategy in the treatment of perioperative stroke complicating CEA, especially when carotid dissection represents the main anatomic problem.

Surgical and percutaneous myocardial angiogenesis induction. Part II--neoangiogenesis.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable to a subset of patients with angina refractory to medical treatment. Bypass surgery might not be feasible because of lack of suitable conduits, diffuse coronary disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. We have previously reviewed the available experience with laser-induced direct myocardial revascularization, one of the new potential treatment modalities for this patient subset. One of the potential mechanisms of action for laser treatment is the induction of neoangiogenesis. In the second part of our article we review the available experience with the induction of myocardial angiogenesis using different growth factors or the genes encoding for them.

Intravascular ultrasound criteria for the assessment of the functional significance of intermediate coronary artery stenoses and comparison with fractional flow reserve.

The functional significance of coronary artery stenoses of intermediate severity is important in determining strategy in patient care. Intravascular ultrasound (IVUS) is often used to evaluate coronary stenosis severity. However, at present, few data are available about the role IVUS in the assessment of functional significance of intermediate lesions. Myocardial fractional flow reserve (FFR) <0.75 is a reliable index of a functionally severe coronary stenosis. In 53 lesions we assessed (1) by pressure wire: FFR (index of functional significance), and (2) by IVUS: minimal lumen cross-sectional area (MLA, square millimeters), minimal lumen diameter (MLD, millimeters), lesion length (millimeters), and percent area stenosis at the lesion site. By regression analysis, percent area stenosis and lesion length had a significant inverse correlation with FFR (r = -0.58, p <0.001, r = -0.41, p <0.004, respectively). MLD and MLA showed a significant positive relation with FFR (r = 0.51, p <0.001, r = 0.41, p <0.004, respectively). By using a receiver operating characteristic (ROC) curve, we identified a percent area stenosis > 70% (sensitivity 100%, specificity 68%), a MLD < or = 1.8 mm (sensitivity 100%, specificity 66%), a MLA < or =4.0 mm2 (sensitivity 92%, specificity 56%), and a lesion length of >10 mm (sensitivity 41%, specificity 80%) to be the best cut-off values to fit with a FFR <0.75. The combined evaluation of both percent area stenosis and MLD made the IVUS examination more specific (sensitivity 100%, specificity 76%). In 53 intermediate coronary lesions found by angiography, IVUS area stenosis >70%, MLD < or =1.8 mm, MLA < or =4.0 mm2, and lesion length > 10 mm reliably identified functionally critical intermediate coronary stenoses.

Angioplasty of atherosclerotic and fibromuscular renal artery stenosis: time course and predicting factors of the effects on renal function.

The effects of percutaneous transluminal renal angioplasty (PTRA) on the renal function of stenotic kidneys are usually assessed by evaluating the changes in serum creatinine, which is quite a rough indicator of glomerular filtration rate (GFR). In 27 hypertensive patients with 19 atherosclerotic and 11 fibromuscular significant renal artery stenoses, we investigated with renal scintigraphy the short-term (5 days) and long-term (10 months) effects of a technically successful PTRA (in seven cases combined with a stent implantation) on GFR of the stenotic and contralateral kidneys; these measurements were combined with those of plasma renin activity (PRA) and of angiotensin II (AII). We found that in short-term studies after PTRA GFR rose from 29.7 +/- 3.5 to 34.6 +/- 3.1 mL/min and from 36.9 +/- 4.0 to 45.1 +/- 4.3 mL/min, respectively, in atherosclerotic and fibromuscular poststenotic kidneys. In long-term studies GFR further and significantly increased, to 37.8 +/- 3.2 mL/min in the former group, whereas it stabilized in the latter group (46.0 +/- 3.6 mL/min). In patients with fibromuscular stenosis these changes in GFR were associated with clear-cut reductions in blood pressure (BP), PRA, and AII; these decrements also occurred in patients with atherosclerotic stenosis but to a much lesser extent. We also found that in short- and long-term studies the percent of PTRA-induced increments of GFR in the poststenotic kidneys were inversely correlated with the baseline values of GFR. In addition, the absolute and percent increments of GFR were positively correlated with the basal levels of AII. Thus the time course of the improvement in GFR after angioplasty may differ in kidneys, depending on the etiology of the stenosis, in that in those with fibromuscular stenosis it was entirely apparent within a few days whereas in those with atherosclerotic stenosis it required several months to be fully expressed. Also, it appears that the more compromised kidneys are those that benefit most from the dilatation and that AII levels are useful indicators of the possibility that the stenotic kidney will have a favorable functional outcome in terms of restoration of renal blood flow.

Plasma endothelin levels: a meaningless number?

Endothelin (ET)-1 is a potent vasoactive peptide which is mostly secreted toward the vessel wall and the circulatory levels of which are quite low; for these reasons changes in plasma ET-1 may be difficult to detect even after the application of strong stimuli, which, in theory, should profoundly alter its production. We have examined the effects of a number of such stimuli and found that in humans the only one which consistently increased plasma ET-1 was the exposure to hypobaric hypoxia; moreover under these circumstances the increments in plasma ET-1 were correlated with the changes in pulmonary systolic pressure, suggesting a role of circulating ET-1 in the adaptation of pulmonary vessels to high altitude. In contrast no consistent changes of ET-1 were observed in response to sympathetic activation induced either by exposure to cold, standing, reduction in blood pressure and blood withdrawal. In response to angioplasty of renal artery stenosis a concomitant reduction in plasma ET-1 and angiotensin II (AngII) was observed in patients who, prior to angioplasty, had a high degree of activation of the renin system, supporting the possibility that in these specific conditions AngII may actually stimulate ET-1 production in vivo.

Progressive decrease of outflow gradient and septum thickness after percutaneous alcoholization of the interventricular septum in hypertrophic obstructive cardiomyopathy.

BACKGROUND: The aim of this study was to evaluate the immediate- and mid-term results of percutaneous transluminal septal myocardial ablation (PTSMA) of the interventricular septum performed in 15 consecutive patients with hypertrophic obstructive cardiomyopathy between 1996 and 1999. METHODS: Prior to intervention, all patients (7 males, 8 females, mean age 62 +/- 11 years) complained of severe dyspnea (NYHA functional class III-IV) despite medical treatment with beta-blockers and/or verapamil. Family history of hypertrophic cardiomyopathy was present in 2 cases. Dehydrated alcohol (4.8 +/- 1.5 ml/pt) was selectively infused into the first septal perforator artery through over-the-wire balloon catheters. In 5 patients a second or a third septal branch was treated because the intraventricular gradient persisted above 50 mmHg after the initial alcohol infusion. RESULTS: Alcohol infusion induced an average peak creatine phosphokinase level of 1,524 +/- 427 IU/l. No iterating ventricular arrhythmias occurred during the procedure or in the 2-3 days of continuous ECG monitoring after the procedure. Two patients (13%) developed a complete atrioventricular block after the procedure, requiring permanent double-chamber pacing. Electrocardiographic changes included a > 2 mm ST segment elevation and transient right bundle branch block or left anterior/left posterior hemiblock in all patients. Peak basal intraventricular gradient decreased from 80 +/- 27 to 24 +/- 27 mmHg (p < 0.01) during cardiac catheterization and from 81 +/- 27 to 35 +/- 25 mmHg (p < 0.01) at the echocardiographic control performed during the hospital stay. At follow-up (mean 5.1 +/- 3.6 months), all patients were in NYHA functional class I or II. Repeat echocardiography showed a further significant decrease in intraventricular gradient to 25 +/- 26 mmHg (p < 0.01) and a progressive decrease in intraventricular septum thickness (25 +/- 5 mm before treatment, 21 +/- 6 mm before hospital discharge, 17 +/- 3 mm at follow-up, p < 0.01). CONCLUSIONS: PTSMA of the intraventricular septum effectively relieves symptoms in selected patients with hypertrophic obstructive cardiomyopathy. The immediate decrease in intraventricular gradient is followed by a further decline at follow-up with a progressive reduction in the intraventricular septum thickness.

Surgical and percutaneous myocardial angiogenesis induction. Part I--laser revascularization.

Coronary artery bypass surgery and angioplasty provide symptomatic relief in patients with ischemic heart disease, but despite advancement in technique and devices, these methods are not applicable in a subset of patients with angina refractory to medical treatment. Bypass surgery may not be feasible because of lack of suitable conduits, diffuse coronary artery disease or poor distal run-off, and coronary angioplasty is sometimes not applicable due to chronic total occlusion, diffuse disease or extreme tortuosity. Transmyocardial laser revascularization and the stimulation of neoangiogenesis by a variety of growth factors have recently emerged as a new tool in the management of these patients. In the first part of this article, we review laser-induced direct myocardial revascularization, its indications, potential risks, and published clinical trials. The induction of neoangiogenesis using different growth factors or the genes encoding for them will be the subject of the second part of our review.

Successful treatment of a bifurcation lesion with the Carina Bard stent: A case report.

In the last years new techniques and user-friendly stents have improved the results of stent implantation in coronary bifurcational lesions but difficulties in stent deployment and incomplete coverage of the bifurcation remain a problem. We describe the case of a proximal lesion of the anterior descending artery involving a large diagonal branch treated with the Carina Bard bifurcate stent, a new device that allows the complete immediate coverage of a bifurcational lesion with a single stent. Cathet. Cardiovasc. Intervent. 48:89-92, 1999.

Renovascular hypertension. Clinical and diagnostic clues.

Renovascular hypertension (RVH), although relatively rare, is the most frequent among the secondary forms of arterial hypertension; in addition interventional radiology has remarkably increased, because of its relative invasiveness, the possibilities of treating and in many cases curing RVH bypassing the traditional surgical approach. For these reasons in recent years a number of screening tests has been developed and added to renal angiography and to the measurement of plasma renin which, still now, represent the reference methods among the morphological and the functional tests respectively. These new and promising techniques include the magnetic resonance angiography, the spiral computed tomography, the renal scintigraphy and the ultrasound scanning of renal arteries with the associated measurement of velocimetric indices. In selected populations all these methods have been shown to possess an high specificity and sensitivity but if applied to a general population of hypertensive patients their positive predictive values are going to be necessarily low because of the low prevalence of the disease. Accordingly, it is mandatory for the physician, before sending patients to these investigations, to preselect those who, on the basis of a thorough clinical examination are more likely to harbour a renal artery stenosis.