Renal artery lesions in patients with moyamoya disease: angiographic findings.
(25/737)
BACKGROUND AND PURPOSE: Renal artery lesions in moyamoya disease have been described sporadically in several case reports. The purpose of this study is to evaluate the angiographic findings of renal artery lesions in moyamoya disease and to determine the prevalence of renal artery lesions in patients with moyamoya disease. METHODS: Eighty-six consecutive patients with idiopathic moyamoya disease were prospectively examined with both cerebral angiography and abdominal aortography. The findings of abdominal aortography were reviewed for the presence and appearance of renal artery lesions and compared with the clinical data and cerebral angiographic findings. RESULTS: Of 86 patients with idiopathic moyamoya disease, 7 patients (8%) were found to have renal artery lesions. Six patients (7%) had stenosis in the renal artery, and 1 patient (1%) had a small saccular aneurysm in the renal artery. Two patients (2%) with a marked renal artery stenosis presented with renovascular hypertension, which resulted in an intraventricular hemorrhage in 1 patient. Furthermore, the renal artery stenosis in the 2 patients with renovascular hypertension was successfully treated with percutaneous transluminal angioplasty. There was no significant correlation between the presence of renal artery lesions and cerebral angiographic findings. CONCLUSIONS: Seven (8%) of 86 patients with moyamoya disease showed renal artery lesions, including 6 stenoses (7%) and 1 aneurysm (1%). Renal artery lesions are a clinically relevant systemic manifestation in patients with moyamoya disease. (+info)
The effect of balloon angioplasty on hypertension in atherosclerotic renal-artery stenosis. Dutch Renal Artery Stenosis Intervention Cooperative Study Group.
(26/737)
BACKGROUND: Patients with hypertension and renal-artery stenosis are often treated with percutaneous transluminal renal angioplasty. However, the long-term effects of this procedure on blood pressure are not well understood. METHODS: We randomly assigned 106 patients with hypertension who had atherosclerotic renal-artery stenosis (defined as a decrease in luminal diameter of 50 percent or more) and a serum creatinine concentration of 2.3 mg per deciliter (200 micromol per liter) or less to undergo percutaneous transluminal renal angioplasty or to receive drug therapy. To be included, patients also had to have a diastolic blood pressure of 95 mm Hg or higher despite treatment with two antihypertensive drugs or an increase of at least 0.2 mg per deciliter (20 micromol per liter) in the serum creatinine concentration during treatment with an angiotensin-converting-enzyme inhibitor. Blood pressure, doses of antihypertensive drugs, and renal function were assessed at 3 and 12 months, and patency of the renal artery was assessed at 12 months. RESULTS: At base line, the mean (+/-SD) systolic and diastolic blood pressures were 179+/-25 and 104+/-10 mm Hg, respectively, in the angioplasty group and 180+/-23 and 103+/-8 mm Hg, respectively, in the drug-therapy group. At three months, the blood pressures were similar in the two groups (169+/-28 and 99+/-12 mm Hg, respectively, in the 56 patients in the angioplasty group and 176+/-31 and 101+/-14 mm Hg, respectively, in the 50 patients in the drug-therapy group; P=0.25 for the comparison of systolic pressure and P=0.36 for the comparison of diastolic pressure between the two groups); at the time, patients in the angioplasty group were taking 2.1+/-1.3 defined daily doses of medication and those in the drug-therapy group were taking 3.2+/-1.5 daily doses (P<0.001). In the drug-therapy group, 22 patients underwent balloon angioplasty after three months because of persistent hypertension despite treatment with three or more drugs or because of a deterioration in renal function. According to intention-to-treat analysis, at 12 months, there were no significant differences between the angioplasty and drug-therapy groups in systolic and diastolic blood pressures, daily drug doses, or renal function. CONCLUSIONS: In the treatment of patients with hypertension and renal-artery stenosis, angioplasty has little advantage over antihypertensive-drug therapy. (+info)
The prevalence and associated risk factors of renal artery stenosis in patients undergoing cardiac catheterization.
(27/737)
Renal artery stenosis may be a cause of hypertension and a potential contributor to progressive renal insufficiency. However, the prevalence of renal artery disease in a general population is poorly defined. The purposes of this study were to evaluate the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing routine cardiac catheterization, and to identify the risk factors for renal artery stenosis. After left ventriculography, abdominal aortography was performed to screen for the presence of renal artery stenosis. A total of 427 patients (274 males, 153 females) were studied and the mean age was 59 years. Renal artery narrowing was identified in 10.5% of patients. Significant (> or = 50% diameter narrowing) renal artery stenosis was found in 24 patients (5.6%) and insignificant stenosis was found in 21 patients (4.9%). Significant unilateral stenosis was present in 4.2% of patients and bilateral stenosis was present in 1.4%. The stem of the renal artery was a more common site of stenosis in 62.2% of patients than in the ostium (37.8%), but the severity of stenosis was not significantly different according to the site of stenosis. By univariate and multivariate logistic regression analysis, the association of clinical variables with renal artery stenosis was assessed. Multivariable predictors included age, hypertension and peripheral vascular disease (p < 0.05). The variables such as sex, smoking history, hyperlipidemia, renal insufficiency, as well as the presence of obesity, severity of coronary heart disease and D.M., were not associated. In conclusion, the prevalence of angiographically-determined renal artery narrowing in a patient population undergoing cardiac catheterization is 10.5%. Old age, hypertension and evidence of peripheral vascular disease represent the predictors of renal artery stenosis. (+info)
Incidence and treatment of intraoperative technical problems during endovascular repair of complex abdominal aortic aneurysms.
(28/737)
PURPOSE: The purpose of this study was to assess the incidence and management of intraoperative technical problems during endovascular repair (EVR) of complex abdominal aortic aneurysms (AAA). METHODS: From February 1995 to March 1999, 204 EVRs of nonruptured AAA were performed at our institution. One hundred seventy-six patients had an in-house custom-made graft; 172 were aorto-uni-iliac grafts, and four were aortoaortic grafts. Twenty- eight patients had a bifurcated graft. One hundred fourteen patients (56%) were high risk for conventional open repair. One hundred nine patients (53%) were not suitable for most commercially available devices. RESULTS: Intraoperative technical problems occurred in 81 patients (40%). There were 37 endoleaks (27 proximal, 10 distal), 15 graft stenoses, one failure of graft deployment, two graft thromboses, three aortoiliac ruptures, five renal artery occlusions (one bilateral, four unilateral), and 18 internal iliac occlusions (five bilateral, 13 unilateral). Endovascular management of these problems was successful in 37 of the 81 patients (46%) and included 15 balloon dilatations, 21 additional stent placements, and one graft thrombectomy. Fifteen of the 81 patients (19%) had open procedures (four periaortic ligature placements, six open aneurysm repairs, three common iliac ligations, and two extra-anatomic bypass grafts). In the remaining 29 patients, the on-table problem was managed expectantly. During follow-up, two of 37 patients (5%) who were treated successfully with endovascular procedures experienced recurrence. There were five deaths (33%) among the 15 patients who underwent open procedures. CONCLUSION: Intraoperative problems occur frequently during the endovascular management of complex aneurysms. Many of these problems can be managed with additional endovascular techniques without an increased risk of recurrence or procedure-related complications. Open procedures in high-risk patients carry a high mortality rate. The team performing EVR of AAA should be skillful in advanced endovascular and open surgical procedures. (+info)
Prevalence of renal artery stenosis in subjects with type 2 diabetes and coexistent hypertension.
(29/737)
OBJECTIVE: To assess the prevalence of renal artery stenosis (RAS) in subjects with type 2 diabetes and coexistent hypertension by using magnetic resonance angiography (MRA) of the renal arteries, to assess clinical and biochemical predictors of RAS, and to assess the hemodynamic significance of RAS, by using the captopril test (a measure of the response of plasma renin activity to a single oral dose of captopril). RESEARCH DESIGN AND METHODS: A total of 117 subjects with type 2 diabetes and coexistent hypertension between 40 and 70 years of age and with creatinine concentrations < 150 micromol/l were recruited from two inner-city general diabetes clinics. All subjects underwent MRA of the renal arteries. In a subgroup of 85 subjects, data concerning possible clinical and biochemical predictors of RAS were collected, and the captopril test was performed. For comparison of a continuous variable between subjects with a positive MRA and those with a negative MRA, the Mann-Whitney test was used. For comparison of a discrete variable between subjects with a positive MRA and those with a negative MRA, Fisher's exact test was used. RESULTS: The prevalence of RAS detected by using MRA in 117 hypertensive type 2 diabetic subjects was 17%; 19 subjects had unilateral RAS, and only 1 subject had bilateral RAS. A femoral bruit was significantly more common in subjects with a positive MRA versus subjects with a negative MRA (21 vs. 0%; Fisher's exact test P < 0.005); however, other clinical features of atherosclerotic disease were not statistically associated. Greater duration of hypertension and treatment with statins were features of subjects with RAS (P < 0.05). The captopril test was negative in all subjects, although the antihypertensive response to oral captopril was significantly greater in subjects with RAS detected by MRA. CONCLUSIONS: RAS is common in hypertensive type 2 diabetic subjects. The presence of a femoral bruit is a useful predictive clinical marker. The captopril test is not useful in predicting the hemodynamic significance of RAS in this patient group. (+info)
Intrarenal angiotensin II augmentation in angiotensin II dependent hypertension.
(30/737)
In several models of angiotensin II (ANG II) dependent hypertension, intrarenal ANG II levels increase to a much greater extent than the circulating levels even though the renal renin levels are decreased. The 2-kidney-1-clip (2K1C) Goldblatt rat model is particularly intriguing because hypertension develops in the presence of an intact kidney which would be expected to maintain sodium balance and protect against hypertension. Although the non-clipped kidney becomes renin depleted, it exhibits enhanced microvascular reactivity and increased tubular fractional sodium reabsorption. The non-clipped kidney ANG II content is either elevated or unchanged and proximal tubular fluid ANG II concentrations are not suppressed compared to the nanomolar concentrations found in normal rats. These results suggest that intrarenal ANG II content can be regulated independently of renal renin content. A similar hypertensive process occurs in rats infused chronically with low doses of ANG II. Renal ANG II content increases over 14 days to a greater extent than the circulating concentrations. Functionally, ANG II infused rats demonstrate reduced sodium excretion and marked suppression of pressure natriuresis. These ANG II dependent influences on kidney function contribute to the maintenance of hypertension. Renal augmentation of ANG II, hypertension, and suppressed sodium excretion are blocked by AT1 receptor blockers. To study the mechanisms responsible for intrarenal ANG II augmentation, we infused a different form of ANG II (Val5 ANG II), that can be separated from endogenous ANG II by HPLC. These results indicated that the increased renal ANG II content was due to accumulation of circulating ANG II in addition to continued production of endogenous ANG II. The renal accumulation of Val5-ANG II was markedly reduced by concomitant treatment with the AT1 receptor blocker, losartan. In addition, we found an unchanged overall ANG II-AT1 receptor protein which probably contributes to the maintained ANG II dependent influences. Collectively, the data support the concept that there is internalization of ANG II through an AT1 receptor mediated process and that some of the internalized ANG II is protected from degradation. The augmented intrarenal ANG II coupled with sustained levels of AT1 receptors contribute to the continued ANG II dependent suppression of renal function and sodium excretion thereby maintaining the hypertension. (+info)
Captopril-induced changes in MAG3 clearance in patients with renal arterial stenosis and the effect of renal angioplasty.
(31/737)
Angiotensin-converting enzyme inhibition by captopril decreases renal (131)I-o-iodohippurate sodium or iothalamate extraction in patients with renal artery stenosis (RAS). This study investigated the effect of captopril on another renal radiopharmaceutical, (99m)Tc-mercaptoacetyltriglycine (MAG3), in particular its plasma clearance. METHODS: Three groups of patients were studied. Group I contained 22 patients with hypertension but a low likelihood of RAS according to negative captopril renography results, confirmed by angiography in 5. Group II contained 22 hypertensive patients with RAS documented by angiography and positive captopril and plasma renin response. Group III contained 10 patients after successful percutaneous transluminal renal angioplasty (PTRA) with negative captopril renography results. The 60-min, single-sample technique was used for measurement of the plasma clearance of MAG3 during baseline and captopril renography. RESULTS: In 18 of 22 group I patients, clearance increased (P < 0.01) during captopril renography compared with baseline conditions, whereas in 18 of 22 group II patients, clearance decreased (P< 0.01). In group III patients, clearance was not significantly altered. The clearance decrease in group II did not correlate with the blood pressure decrease or plasma renin activity increase during captopril renography. CONCLUSION: Renal function assessed by MAG3 plasma clearance decreases in hypertensive patients with RAS but increases in patients without RAS. MAG3 clearance measurements during baseline and captopril renography can thus serve as additional diagnostic information when investigating patients with hypertension for the possibility of an RAS. (+info)
Evaluation of duplex ultrasound and captopril renography for detection of renovascular hypertension.
(32/737)
BACKGROUND: Renovascular hypertension is the most common form of curable secondary hypertension and, if untreated, may lead to end-stage kidney disease. Given that renal function and hypertension may improve after renal angioplasty, it is pertinent to identify patients with renal artery stenosis. The aim of the present study was to evaluate both duplex ultrasound and captopril renography for detection of renal artery stenosis among hypertensive patients. METHODS: To avoid selection bias, all patients referred to our center for evaluation of renovascular hypertension were asked to participate in the study. Patients were examined by intra-renal duplex ultrasound (N = 121), measuring pulsatility index and acceleration of the blood flow during early systole. In 98 patients, 99mTc-DTPA captopril renography was performed in conjunction with duplex ultrasound. Renal angiography was performed in all patients regardless of the results of the noninvasive tests. RESULTS: The prevalence of renal artery stenosis was 19%. In the 98 patients examined by both duplex ultrasound and captopril renography, sensitivity and positive predictive values for detection of a renal artery stenosis of 50% degree or more were 84 and 76%, respectively, for duplex ultrasound, whereas captopril renography was associated with a sensitivity and positive predictive value of 68% for both (P = NS). Specificity and negative predictive values were 94 and 96%, respectively, for duplex ultrasound, whereas the corresponding values for captopril renography were 92% for both (P = NS). Specificity and negative predictive values were 94 and 96%, respectively, for duplex ultrasound, whereas the corresponding values for captopril renography were 92% for both (P = NS). CONCLUSIONS: Both duplex ultrasound and captopril renography are associated with high specificity and negative predictive values for detection of renal artery stenosis. Sensitivity and positive predictive values are at least as good for duplex ultrasound compared with captopril renography. Given that duplex ultrasound is easier to perform and more cost effective, we propose that it should be the method of first choice when screening for renal artery stenosis in a hypertensive population. (+info)