MR-derived renal morphology and renal function in patients with atherosclerotic renovascular disease

Appropriate selection of patients with atherosclerotic renovascular disease (ARVD) for revascularization might be improved if accurate non-invasive investigations were used to assess severity of pre-existing parenchymal damage. The purpose of this study was to evaluate the associations between magnetic resonance imaging (MRI)-measured renal morphological parameters and single-kidney glomerular filtration rate (GFR) in ARVD. Three-dimensional (3D)-MRI was performed on 35 ARVD patients. Renal bipolar length (BL), parenchymal volume, parenchymal (PT), and cortical thicknesses (CT) were measured in 65 kidneys. Thirteen kidneys were supplied by normal vessels, 13 had insignificant (<50%) renal artery stenosis (RAS), 33 significant (>or=50%) RAS, and six complete vessel occlusion. All patients underwent radioisotopic measurement of single-kidney GFR (isoSK-GFR). Overall, 3D parameters such as parenchymal volume were better correlates of isoSK-GFR (r=0.86, P<0.001) than BL (r=0.78, P<0.001), PT (r=0.63, P<0.001) or CT (r=0.60, P<0.001). Kidneys with >or=50% RAS did show significant reduction in mean CT compared to those supplied by normal vessel (5.67+/-1.63 vs 7.28+/-1.80 mm, P=0.002; 22.1% reduction) and an even greater loss of parenchymal volume (120.65+/-47.15 vs 179.24+/-86.90 ml, P<0.001; 32.7% reduction) with no significant reduction in BL. In a proportion of >or=50% RAS kidneys, a disproportionately high parenchymal volume to isoSK-GFR was observed supporting a concept of 'hibernating parenchyma'. 3D parameters of parenchymal volume are stronger correlates of isoSK-GFR than two-dimensional measures of BL, PT or CT. 3D morphological evaluation together with isoSK-GFR might be useful in aiding patient selection for renal revascularization. Kidneys with increased parenchymal volume to SK-GFR might represent a subgroup with the potential to respond beneficially to angioplasty.     

Preservation of renal function with surgical revascularization in patients with atherosclerotic renovascular disease

OBJECTIVE: Clinical and anatomic factors predictive of a favorable response to renal revascularization performed for renal function salvage remain poorly defined. To clarify decision making in such patients we reviewed a contemporary experience of surgical renal artery revascularization (RAR) performed primarily for preservation of renal function. METHODS: Between June 1990 and March 2001 (ensuring 1 year minimum follow-up), 96 patients with renal insufficiency (serum creatinine [Cr] concentration >or=1.5 mg/dL) and hypertension underwent RAR for preservation of renal function. Study end points included early and late renal function response, progression to dialysis dependence, and long-term survival. Variables potentially associated with these end points were assessed with univariate analysis, Cox regression analysis, and logistic regression analysis, and survival was assessed with the Kaplan-Meier method. RESULTS: Perioperative failure of RAR occurred in 3 patients (3%), with perioperative mortality in 4 patients (4.1%); thus 92 patients were available for long-term follow-up (mean, 39 months). Mean patient age was 70 +/- 9 years with a mean baseline Cr of 2.6 mg/dL (range, 1.5-7.8 mg/dL). Operative management consisted of aortorenal bypass in 38% of patients, extraanatomic bypass in 38% of patients, and endarterectomy in 24% of patients; 32% of patients required combined aortic revascularization and RAR, and 27% underwent bilateral RAR. At hospital discharge renal function had improved (20% decrement in Cr) in 41 (43%) patients, including 7 patients who were removed from dialysis; remained unchanged in 40 (41%) patients; and declined (20% increase in Cr) in 15 (16%) patients. At last follow-up renal function was either improved or unchanged in 72% of patients. Predictors of a favorable response to RAR at last follow-up included stable Cr at hospital discharge (odds ratio [OR], 7.1; 95% confidence interval [CI], 2.5-21.8; P =.0004) and decreased Cr at hospital discharge (OR, 16; 95% CI, 1.6-307.8; P <.0001); bilateral renal artery repair (OR, 3.1; 95% CI, 0.9-10.6; P =.07) approached clinical significance. Predictors of worsened excretory function at last follow-up included decline of renal function at hospital discharge (OR, 28.9; 95% CI, 5.0-165.4; P =.0002), intervention to treat unilateral renal artery stenosis (OR, 3.8; 95% CI, 0.8-16.6; P =.05), and level of baseline Cr (OR, 3.0; 95% CI, 1.0-4.0; P =.04). Progression to dialysis occurred in 16 (17%) patients. Dialysis-free survival at 5 years was 50%, and overall actuarial survival at 5 years was 59%. Predictors of progression to dialysis during follow-up included treatment of complete renal artery occlusion (OR, 6.2; 95% CI, 1.3-29.5; P =.02), early failure of RAR (OR, 3.1; 95% CI, 0.7-14.2; P =.04) and baseline Cr (OR, 2.9; 95% CI, 1.3-6.1; P =.006). CONCLUSION: Long-term clinical success in the preservation of renal function, noted in 70% of patients, can be predicted by the initial response to RAR and by anatomic factors, in particular, bilateral repair. While extreme (mean Cr >or=3.2 mg/dL) renal dysfunction generally is predictive of poor long-term outcome, a subset of patients will experience favorable results, even to the extent of rescue from dialysis. These results may facilitate clinical decision making in the application of RAR for renal function salvage.     

血管紧张素转换酶抑制剂对单侧动脉粥样硬化性肾动脉狭窄患者肾功能的影响

目的 观察血管紧张素转换酶抑制剂(ACEI)对单侧动脉粥样硬化性肾动脉狭窄(ARAS)患者肾功能的影响&#65377;方法 结合临床表现及肾动脉造影结果诊断单侧ARAS患者共49例, 分为ACEI组20例与对照组29例&#65377;记录基础血压, 检测Scr&#65380; BUN&#65380; Alb, 以MDRD公式计算估计肾小球滤过率(eGFR),行肾动脉彩超检查测量肾脏阻力指数(RI)&#65377;每月测量血压,每6个月复查Scr&#65380;Urea&#65380;Alb并计算eGFR, 观察两组患者随访期间肾功能变化&#65377; 结果 两组患者试验前一般临床资料无显著性差异&#65377;平均随访9.9个月,随访期间两组血压均无明显变化(P > 0.05)&#65377;与试验前比,对照组eGFR无明显变化[(74.5±18.3 )ml·min^-1·(相似文献   

Left ventricular morphology and function in patients with atherosclerotic renovascular disease

Atherosclerotic renovascular disease (ARVD) is associated with heart disease. There has been no systematic study of cardiac structure and function in patients with this condition. In this study, the epidemiology of cardiac changes and their relationship to renal function, renovascular anatomy, and BP are delineated. With the use of a cross-sectional design, 79 patients with ARVD and 50 control patients without ARVD underwent echocardiography and 24-h ambulatory BP monitoring. Clinical and biochemical data were collected. Results were analyzed according to renal function, residual renal artery patency, and unilateral or bilateral ARVD. Only 4 (5.1%) patients with ARVD had normal cardiac structure and function. Patients with ARVD (age 70.7 +/- 7.5 yr; estimated GFR 36 +/- 19 ml/min) had significantly more cardiovascular comorbidity (77.2 versus 42.0%; P < 0.001), greater prevalence of left ventricular (LV) hypertrophy (78.5 versus 46.0%; P < 0.001) and LV diastolic dysfunction (74.6 versus 40.0%; P < 0.001), and greater LV mass index (183 +/- 74 versus 116 +/- 33 g/m2; P < 0.001) and LV end-diastolic volume index (82 +/- 35 versus 34 +/- 16 ml/m2; P < 0.001) than control subjects. BP was similar for both patient groups. For patients with ARVD, neither renal function nor renal artery patency predicted a difference in echocardiographic or ambulatory BP monitoring parameters. Patients with bilateral ARVD had greater LV mass index and LV dilation than patients with unilateral disease. Patients with ARVD exhibit a high prevalence of cardiac morphologic and functional abnormalities at early stages of renal dysfunction. Such patients must be identified early in their disease course to allow risk factor modification.     

Revascularization in atherosclerotic renovascular disease: problems beyond the obstruction

The main goal in the treatment of obstructive atherosclerotic renovascular disease (ARVD) is to preserve or recover renal function. The ARVD kidney continues to deteriorate in 20-40% of cases despite restoration of blood flow. Holden et al. report that renal function stabilized or improved in up to 97% of patients with the use of a distal embolic protection device.     

Incidence of end-stage renal disease in medically treated patients with severe bilateral atherosclerotic renovascular disease

Incidence of end-stage renal disease in medically treated patients with severe bilateral atherosclerotic renovascular disease. Atherosclerotic renovascular disease is an important cause of end-stage renal disease (ESRD). The exact incidence of ESRD and the rate of decline in glomerular filtration rate (GFR) in patients with this condition is unknown. We report the mortality, the rate of decline in renal function, and incidence of ESRD in 51 patients with bilateral atherosclerotic renovascular disease followed-up for a median period of 52 months. None of these patients had undergone any surgical or radiological intervention. Renal function was determined by serial measurements of serum creatinine. Bilateral atherosclerotic renovascular disease was associated with a high mortality rate; the crude mortality rate at 60 months was 45%. Assessment of renal function showed impaired renal function at time of angiography and a nonuniform and variable decline in renal function during the period of observation. The median GFR decreased from 39 mL/min (range, 15 to 80 mL/min) at time of angiography to 31 mL/min (range, 10 to 70 mL/min) and 24 mL/min (range, 10 to 40 mL/min) at 24 and 60 months, respectively (P < 0.05). The calculated mean rate of decline in GFR for all patients was 4 mL/min/yr (range, 1 to 16 mL/min/yr). Over the 5 years, there was a progressive increase in the incidence of ESRD. Of the original 51 patients who underwent angiography, six patients reached ESRD. The crude incidence of ESRD was, therefore, 12%. Patients who reached ESRD were characterized by advanced azotemia at the time of angiography (median GFR, 25 mL/min) and a rapid decline in GFR (8 mL/min) compared with patients who did not reach ESRD during the observation period (median GFR, 43 mL/min and an average rate of decline GFR of 3 mL/min).     

Relationship of renal dysfunction to proximal arterial disease severity in atherosclerotic renovascular disease.

BACKGROUND: Renal impairment is common in patients with atherosclerotic renovascular disease (ARVD), but its pathogenesis is uncertain. This study investigated whether any relationship existed between renal function and the severity of proximal renal arterial lesions in patients with ARVD. METHODS: A cohort of 71 patients had creatinine clearance measured at the time of digital subtraction angiography; eight patients were diabetics and were excluded from further analysis. The severity of proximal renovascular lesions was estimated by standard methodology, and patients were sub-grouped according to residual patency of the proximal renal arteries (e.g. normal=2.0; unilateral occlusion )RAO(=1.0). Renal bipolar lengths at ultrasound were also assessed. RESULTS: Sixty-three non-diabetic patients (mean+/-SD age 67.7+/-5.8 years; 34 males) were suitable for study. No differences in renal function (mean+/-SD creatinine clearance (ml/min)) were seen between patients with unilateral (32. 1+/-18.9, n=36) or bilateral (31.7+/-20.9, n=27) disease, or between sub-groups with RAS <60% (28.3+/-13.9, n=15), unilateral RAS >60% (38.9+/-24.6, n=12), bilateral RAS >60% (36.3+/-20.4, n=6) or unilateral RAO (30.3+/-17.7, n=28), and mean average renal size similarly did not differ between the sub-groups. No correlation existed between residual patency and creatinine clearance (r=0.015); mean+/-SD renal function was almost identical in the four patency sub-groups, and average renal size mirrored this pattern. Mean 24-h urinary protein excretion was similar for the four groups, but patients with minimal ARVD had significantly less comorbid vascular disease. CONCLUSIONS: These findings suggest that the severity of proximal renal artery lesions is often unrelated to the severity of renal dysfunction in patients with ARVD. Associated renal parenchymal damage is the more probable arbiter of renal dysfunction, and this should be considered when revascularization procedures are contemplated.     

Management of atherosclerotic renovascular disease: the effect of renal artery stenting on renal function and blood pressure

In the last few years, renal artery stenting has gradually evolved into one of the most important therapeutic modalities in the management of atherosclerotic renovascular disease. Stenting is nowadays preferred by a steadily increasing number of physicians, not only because of its significant contribution to blood pressure control, but also because of its documented ability to maintain, and even improve, renal function. At the same time, procedure-related morbidity and mortality rates are extremely low, while recurrent stenosis rates have been repeatedly reported to be␣minimal. Percutaneous transluminal renal angioplasty (PTRA) and stenting are nowadays considered by many physicians to be the treatment of choice for atherosclerotic renovascular disease.     

Effect of primary renal disease in patients with renovascular insufficiency

The effect of laboratory evidence of renal parenchymal abnormality on the results of renal revascularization in 83 patients with renovascular hypertension was determined. Primary renal disease (PRD) was defined as an abnormal urinalysis (proteinuria, hematuria, or casts) in the absence of urinary infection, or decreased renal function (elevated serum creatinine level greater than 1.5 mg/dl and/or decreased creatinine clearance). All patients were hypertensive on medical therapy preoperatively. Patients were defined as cured if postoperative diastolic blood pressure (BP) was less than 90 mm Hg on no medication and improved if BP less than 90 mm Hg on medication. Sixty-six patients (80%) were cured or improved following revascularization. Of 45 patients (63%) with evidence of PRD preoperatively, 28 (62%) were cured or improved compared with 33 patients without PRD, of whom all (100%) were cured or improved (p less than 0.001). Each of five patients with transplant renal artery stenosis had two operations; four were cured or improved. The serum creatinine level was elevated preoperatively in 37 cases. Eighteen of the 37 (49%) improved to within normal limits following operation. Fifteen patients had simultaneous bilateral renal artery revascularization, and 12 (80%) were cured or improved. Fourteen patients (17%) had concomitant vascular procedures: aortobifemoral bypass (seven), abdominal aneurysm resection (five), femoral endarterectomy (one), and aortoiliac bypass (one). Twelve of these 15 patients had PRD, and 8 of the 12 (67%) were cured or improved. Only one death occurred in the perioperative period. Thirty-eight patients (46%) had been treated for hypertension for more than 12 months before referral.(ABSTRACT TRUNCATED AT 250 WORDS)     

Emerging strategies to preserve renal function

Although there has been tremendous improvement in managing chronic kidney disease (CKD) with angiotensin-converting enzyme (ACE) inhibitors or angiotensin receptor blockers (ARBs) in the last 15 years, CKD still progresses. Therefore, new emerging strategies are needed. The gold standard still lies with optimum renin-angiotensin-aldosterone system blockade, although many questions remain about how this is best achieved, such as regarding the efficacy of combinations of ACE inhibitor and ARBs, supramaximal doses of ARBs alone and combinations of either ACE inhibitor or ARBs with direct renin inhibitors, antialdosterone agents. Other promising molecules currently being tested are endothelin receptor antagonists and glitazones. Also, the role of other current therapies being used during CKD, including statins, vitamin D and erythropoiesis-stimulating agents, will be discussed, as these may also exert nephroprotective effects.     

Clinicopathological correlation in biopsy-proven atherosclerotic nephropathy: implications for renal functional outcome in atherosclerotic renovascular disease.

BACKGROUND: Atherosclerotic renovascular disease (ARVD) is commonly associated with renal failure. It is now recognized that intrarenal damage, (ischaemic or atherosclerotic nephropathy) is a major contributor to the renal impairment in these patients. In this study the impact of histological changes upon renal functional outcome was investigated in patients with atherosclerotic nephropathy. METHODS: The Hope Hospital renal biopsy database (1985-1998) was interrogated for patients with histology compatible with atherosclerotic nephropathy. Case-note review enabled the assessment of several clinical parameters and outcomes, including change in creatinine clearance per year (DeltaCrCl (ml/min/year)), blood pressure control, dialysis need, and death. Renal parenchymal damage was analysed by morphometric analysis (of interstitial fibrosis and glomerulosclerosis) and a semi-quantitative chronic damage score (score 0-3 (normal-severe) for each of glomerulosclerosis, interstitial fibrosis, tubular atrophy, and arteriolar hyalinosis; maximum=12). Patients were stratified into two groups who had either deteriorating (group 1) or stable (group 2) renal function during follow-up. RESULTS: Twenty-five patients (age 64.7+/-10.5, range 43-83 years; 17 male, eight female) were identified. Sixteen patients had undergone angiography; two had significant (>50%) renal artery stenosis. Mean follow-up was 25.6+/-14.8 (range 5-50) months. Group 1 patients had DeltaCrCl -7.4+/-6.8 ml/min/year, n=14 and group 2 patients had DeltaCrCl 4.8+/-7.0 ml/min/year, n=11. Four patients in group 1 developed end-stage renal disease and five patients died (three in group 1 and two in group 2). At study entry, group 1 patients had worse renal function (CrCl 27.6+/-17.6 vs 36.0+/-33.9, NS), greater proteinuria (1.2 vs 0.5 g/24 h, NS), and higher systolic blood pressure (167.1+/-30.8 mmHg vs 150.6+/-37.8, NS) compared with group 2 patients. Group 1 patients showed more glomerulosclerosis (51.6 vs 24.9%, P:<0.01), greater proportional interstitial volume (44.9 vs 33.9%, P:<0.02), and higher overall chronic damage score (P:<0.05) than those in group 2. There was a significant correlation between renal functional outcome and chronic damage score, glomerulosclerosis and proportional interstitial volume for the entire patient cohort. CONCLUSION: In patients with atherosclerotic nephropathy the severity of histopathological damage is an important determinant and predictor of renal functional outcome.     

The management of atherosclerotic renovascular disease

Atherosclerotic renovascular disease (ARVD) seems to be a common clinical condition. ARVD is clinically presented as: 'silent' renal artery stenosis, renovascular hypertension, ischemic nephropathy leading to deterioration of renal function and recurrent 'flash' pulmonary edema. Management of ARVD involves both revascularization and medical treatment. However, the impact of revascularization on kidney function and blood pressure control is a matter of great controversy in view of the results of recent randomized clinical trials. At present, concerted medical management (includes lifestyle modifications, such as smoking cessation) remains the main treatment option for patients with ARVD. However, there is a need to accurately identify individuals who may benefit from renal revascularization.     

Surgical management of atherosclerotic renovascular disease

OBJECTIVE: This review describes the clinical outcome of surgical intervention for atherosclerotic renovascular disease in 500 consecutive patients with hypertension. METHODS: From January 1987 to December 1999, 626 patients underwent operative renal artery (RA) repair at our center. A subgroup of 500 patients (254 women and 246 men; mean age, 65 plus minus 9 years) with hypertension (mean blood pressure, 200 plus minus 35/104 plus minus 21 mm Hg) and atherosclerotic RA disease forms the basis of this report. Hypertension response was determined from preoperative and postoperative blood pressure measurements and medication requirements. Change in renal function was determined with estimated glomerular filtration rates (EGFRs) calculated from serum creatinine levels. Proportional hazards regression models were used for the examination of associations between selected preoperative parameters, blood pressure and renal function response, and eventual dialysis-dependence or death. RESULTS: Two hundred three patients underwent unilateral RA procedures, 297 underwent bilateral RA procedures, and 205 patients underwent combined renal and aortic reconstruction. After surgery, there were 23 deaths (4.6%) in the hospital or within 30 days of surgery. Significant and independent predictors of perioperative death included advanced age (P <.0001; hazard ratio [HR], 3.23; 95% confidence interval [CI], 1.85 to 5.70) and clinical congestive heart failure (P =.013; HR, 3.05; 95% CI, 1.26 to 7.34). Among the patients who survived surgery, hypertension was considered cured in 12%, improved in 73%, and unchanged in 15%. For the entire group, renal function increased significantly after operation (preoperative versus postoperative mean EGFR, 41.1 plus minus 23.9 versus 48.2 plus minus 25.5 mL/min/m(2); P <.0001). For individual patients, with a 20% or more change in EGFR considered significant, 43% had improved renal function (including 28 patients who were removed from dialysis-dependence), 47% had unchanged function, and 10% had worsened function. Preoperative renal insufficiency (P <.001; HR, 2.35; 95% CI, 1.86 to 2.98), diabetes mellitus (P =.007; HR, 2.14; 95% CI, 1.15 to 3.97), prior stroke (P =.042; HR, 1.50; 95% CI, 1.02 to 2.22), and severe aortic occlusive disease (P =.003; HR, 1.69; 95% CI, 1.19 to 2.31) showed significant and independent associations with death or dialysis during the follow-up examination period. After operation, blood pressure cured (P =.014; HR, 0.52; 95% CI, 0.30 to 0.88) and improved renal function (P =.011; HR, 0.40; 95% CI, 0.19 to 0.81) showed significant and independent associations with improved dialysis-free survival rate. All categories of function response and time to death or dialysis showed significant interactions with preoperative EGFR. CONCLUSION: The surgical correction of atherosclerotic renovascular disease resulted in blood pressure benefit and retrieval of renal function in selected patients with hypertension. The patients with cured hypertension or improved EGFR after operation showed increased dialysis-free survival as compared with other patients who underwent surgery.     

肾动脉狭窄患者肾动脉支架置入术后再狭窄及肾功能和血压的改变

目的评估肾动脉支架术后再狭窄的发生及肾功能及血压的改变。方法对135 例单侧或双侧肾动脉明显狭窄(管腔内径减少≥70％)的患者行肾动脉支架置入术(PTRAS),术后行肾动脉造影、血压及血肌酐(Scr)的随访观察。结果 135例患者植入147枚支架均获成功。术后肾动脉造影随访率70％,平均随访时间为(7．2±5．6)月,再狭窄率为7．4％。血压及肾功能随访率为95％,平均随访时间(22±6)月,随访患者的收缩压与舒张压均明显下降,分别为 [(172±23)比(159±20)mm Hg,P<0．05,(93±16)比(85±13)mm Hg,P<0．05]。但术后12个月及24个月Scr和GFR与术前比较无显著性差异。结论肾动脉支架置入术后的再狭窄率较低,PTRAS有助于患者的血压控制。