[Revascularization of the myocardium and kidneys in patients with combined atherosclerotic lesions of coronary and renal arteries]

The study included a total of 109 patients presenting with combined atherosclerotic lesions of coronary and renal arteries. Depending on severity of angina pectoris, the patients were subdivided into two groups. Group One consisted of patients subjected to revascularization of the myocardium and kidneys, and Group Two comprised those with a dominating clinical picture of vasorenal hypertension syndrome and undergoing surgery on renal arteries alone. Combined revascularizations were carried out in 31 patients. Of these, five underwent single-stage endovascular interventions on coronary and renal arteries. Isolated interventions were performed in 78 patients. Selectivity of revascularisations of vascular basins was determined first of all by the degree of coronary impairments, arterial hypertension, and the presence of chronic renal failure. No cases of hospital lethality were registered. The 10-year survival rate after renal revascularization amounted to 80.1%, after combined operations to 90.9%. In the immediate postoperative period improvement following isolated renal revascularization was achieved in 62 (86.1%) patients, after isolated coronary artery bypass grafting and combined operation - in all patients. The long-term outcomes turned out to be better after combined operations (80.0%) as compared to those after isolated operations on renal arteries (70.3%).

Renal artery stenting crucial to the recovery from acute worsening of chronic renal failure

Recent randomized studies have failed to note any benefits to adding renal artery stenting to optimal medical therapy in patients with atherosclerotic renal artery stenosis (ARAS). We herein present the case of a 75-year-old woman with acute worsening of chronic renal failure in whom renal stenting was essential to saving the patient's life and avoiding dialysis. Although the long-term usefulness of renal artery stenting for ARAS remains controversial, this procedure should be kept in mind as a viable option for treating acute critical cases such as this.

Co-existence of carotid artery disease, renal artery stenosis, and lower extremity peripheral arterial disease in patients with coronary artery disease

In atherosclerosis, carotid artery stenosis (CAS), renal artery stenosis (RAS), lower extremity peripheral arterial disease (PAD), and coronary artery disease (CAD) are common pathologic lesions; their interrelationship is, however, unclear. We studied concomitant multiple atherosclerotic lesions in patients with CAD to understand their prevalence and relations. A cross-sectional analysis was performed on data from consecutive patients who underwent nonemergent coronary angiography. Simultaneous carotid and renal artery Doppler studies and ankle-brachial systolic pressure measurements were reviewed to diagnose concomitant lesions and their severity. The study included 1,734 patients (aged 71 ± 9 years; 70% men), with prevalences of CAS, RAS, lower extremity PAD, and CAD of 6%, 7%, 13%, and 72%, respectively. In patients with CAD (n = 1,253), the prevalences of CAS, RAS, and lower extremity PAD were 7%, 9%, and 16%, respectively; 24% CAD patients had ≥1 additional atherosclerotic lesion. Significant interactions among the prevalences of these lesions were found. In addition, the extent of CAD and the prevalences of CAS, RAS, and lower extremity PAD were significantly correlated. Multivariate analysis supported these relationships. In conclusion, the prevalences of CAS, RAS, lower extremity PAD, and CAD were strongly interrelated in the study population; CAD severity was related to that of other atherosclerotic lesions. Additional systematic screening of other concomitant atherosclerotic lesions is recommended, especially in CAD patients having multivessel disease, left main disease, and/or already diagnosed with other concomitant atherosclerotic lesions.

[Feasibility of non-contrast enhanced magnetic resonance angiography for diagnosis of renal artery stenosis in elderly patients]

OBJECTIVE

To evaluate the diagnostic efficacy of IFIR-FIESTA technique in detecting renal artery stenosis in elderly patients.

METHODS

Twenty-seven aged patients underwent both IFIR-FIESTA and 3D CE-MRA examinations. The imaging quality and renal artery stenosis grades were evaluated. Kappa test was used to assess the consistency between the two methods. With CE-MRA as the reference, the diagnostic sensitivity, specificity, accuracy, PPV and NPV for IFIR-FIESTA were calculated in detecting renal artery stenosis.

RESULTS

The images by the two methods were 100% qualified for diagnosis, although the image quality of CE-MRA was significantly better. IFIR-FIESTA and CE-MRA showed excellent consistency in detecting renal artery stenosis. With CE-MRA as the reference, the diagnostic sensitivity, specificity, accuracy, PPV and NPV for IFIR-FIESTA were 97.1%, 100%, 98.1%, 100%, and 95% in detecting renal artery stenosis, respectively.

CONCLUSION

IFIR-FIESTA is feasible as a routine examination for detecting renal artery stenosis in elderly patients.

Role of non-contrast balanced steady-state free precession megnetic resonance angiography compared to contrast-enhanced megnetic resonance angiography in diagnosing renal artery stenosis: a meta-analysis

BACKGROUND

Balanced steady-state free precession MR angiography (b-SSFP MRA) has shown great promise in diagnosing renal artery stenosis (RAS) as a non-contrast MR angiography (NC-MRA) method. However, results from related studies are inconsistent. The purpose of this meta-analysis was to assess the accuracy of b-SSFP MRA compared to contrast-enhanced MR angiography (CE-MRA) in diagnosing RAS.

METHODS

English and Chinese studies that were published prior to September 4, 2013 and that assessed b-SSFP MRA diagnostic performance in RAS patients were reviewed. Quality of the literature was assessed independently by two observers. The statistical analysis was adopted by the software of Meta-Disc version 1.4. Using the heterogeneity test, a statistical effect model was chosen to calculate different pooled weighted values. The receiver operator characteristic (ROC) space and Spearman correlation coefficient were to explore threshold effect. Sensitivity analysis and the publication bias were performed to demonstrate if the pooled estimates were stable and reliable. We produced forest plots to calculate the pooled values and corresponding 95% confidence interval (CI) of sensitivity, specificity, positive likelihood ratio (PLR), negative likelihood ratio (NLR), diagnostic odds ratio (DOR), and constructed a summary receiver operating characteristic curve (SROC) to calculate the area under the curve (AUC).

RESULTS

A total of 10 high quality articles were used in this meta-analysis. The studies showed a high degree of heterogeneity. The "shoulder-arm" shape in the ROC plot and the Spearman correlation coefficient between the log(SEN) and log(1-SPE) suggested that there was a threshold effect. Sensitivity analysis demonstrated that the actual combined effect size was equal to the theoretical combined effect size. The publication bias was low after quality evaluation of the literature and the construction of a funnel plot. The pooled sensitivity was 0.88 (95% CI, 0.83-0.91) and pooled specificity was 0.94 (95% CI, 0.93-0.95); pooled PLR was 14.57 (95% CI, 9.78-21.71]) and pooled NLR was 0.15 (95% CI, 0.11-0.20). The AUC was 0.964 3.

CONCLUSION

In contrast to CE-MRA, the b-SSFP MRA is more accurate in diagnosing RAS, and may be able to replace other diagnostic methods in patients with renal insufficiency.

[Renal artery thrombosis and renal infarction, diagnostic and therapeutic difficulties--reports of two cases]

Renal artery thrombosis (RAT) is a rare condition, with a poor prognosis, which can lead to renal infarction (RI). RAT has both cardiogenic etiology (arrhythmia, endocarditis, valvular heart disease, coronary disease) and noncardiogenic etiology (renal artery injury and/or instrumentation, fibromuscular dysplasia, coagulation disorders, homocystinuria, cocaine intake). In 30% of cases RAT etiology remains undetermined and then it is labeled idiopathic RAT. Because of the absence of typical symptoms and abnormalities in laboratory tests as well as often ambiguous results of imaging scans, RAT frequently remains undiagnosed. Presently RAT treatment standards are lacking due to its being a rare disease, which renders making treatment decisions difficult. However, because of a high risk of developing its serious complication in the form of RI, it seems necessary to introduce patient-tailored treatment in each case. Two cases presented in this paper demonstrate diagnostic difficulties and the necessity to introduce personalized treatment. Case 1 concerns idiopathic RAT in which anticoagulation therapy was introduced. Case 2 describes cardiogenic RAT with renal artery stenosis treated interventionally, i.e., percutaneous transluminal angioplasty (PTA) combined with antiplatelet drugs. In both cases recanalization of the renal artery was successful and a stable renal function was achieved.

Acute bilateral renal artery chimney stent thrombosis after endovascular repair of a juxtarenal abdominal aortic aneurysm

The use of "chimney" stents to augment the proximal landing zone for endovascular aneurysm repair has been increasingly reported. Despite mounting enthusiasm for this technique, the durability of this type of repair and capability to preserve perfusion to target branches remains a paramount concern. Here, we report management of a patient presenting with acute bilateral renal chimney stent thrombosis and a type Ia endoleak.

The rise and fall of renal artery angioplasty and stenting in the United States, 1988-2009

OBJECTIVE

Optimal management of renal artery stenosis (RAS) remains unclear. Recent randomized controlled trials have shown no clear benefit with percutaneous transluminal angioplasty with or without stenting (PTRA/S) over medical management. We hypothesize that interventions for RAS are decreasing nationally.

METHODS

The Nationwide Inpatient Sample, 1988-2009, was used to identify patients with a diagnosis of renal artery atherosclerosis undergoing open surgical repair (bypass or endarterectomy) or PTRA/S. The rate of interventions, in-hospital death, and perioperative outcomes were analyzed over time. Additionally, we used individual state inpatient and ambulatory databases to better understand the influence of outpatient procedures on current volume and trends.

RESULTS

We identified 308,549 PTRA/S and 33,147 open surgical repairs. PTRA/S increased from 1.9/100K adults in 1988 to 13.7 in 2006 followed by a decrease to 6.7 in 2009. Open surgical repair steadily decreased from 1.3/100K adults in 1988 to 0.3 in 2009. In 2009, PTRA/S procedures (6.4/100K adults) greatly outnumbered procedures done by open repair alone (0.1/100K), combined open renal and aortic repair (0.2/100K), and combined PTRA/S and endovascular aneurysm repair (0.3/100K). From 2005 to 2009 33,953 patients underwent PTRA/S in the states of New Jersey Maryland, Florida, and California combined. The total number of PTRA/S performed in the outpatient setting remained stable from 2005 (3.8/100K) to 2009 (3.7/100K), whereas the total number of inpatient procedures mirrored the national trend, declining from 2006 (7.9/100K) to 2009 (4.2/100K). PTRA/S had lower in-hospital mortality (0.9% vs 4.1%; P < .001) compared with open repair. PTRA/S patients were more likely to be discharged home (86.2% vs 76.3%; P < .001) and had a shorter length of stay (4.4 vs 12.3 days; P < .001). Mortality was higher after combined open renal and open aortic surgery compared to open repair alone (6.5% vs 4.1%; P < .001). Mortality was similar for combined PTRA/S and endovascular aneurysm repair compared with PTRA/S alone (1.2% vs 0.9%; P = .04).

CONCLUSIONS

The performance of PTRA/S procedures for the management of RAS has decreased significantly after 2006. An increasing proportion of these procedures are performed in the outpatient setting. PTRA/S remains the dominant revascularization procedure for RAS with lower in-hospital mortality and morbidity than surgery.

Analysis of the sensitivity and specificity of noninvasive imaging tests for the diagnosis of renal artery stenosis

BACKGROUND

Aging and atherosclerosis are related to renovascular hypertension in elderly individuals. Regardless of comorbidities, renal artery stenosis is itself an important cause of cardiovascular morbidity and mortality.

OBJECTIVE

To define the sensitivity, specificity, positive predictive value, and negative predictive value of noninvasive imaging tests used in the diagnosis of renal artery stenosis.

METHODS

In a group of 61 patients recruited, 122 arteries were analized, thus permitting the definition of sensitivity, specificity, and the relative contribution of each imaging study performed (Doppler, scintigraphy and computed tomographic angiography in comparison to renal arteriography).

RESULTS

The mean age was 65.43 years (standard deviation: 8.7). Of the variables related to the study population that were compared to arteriography, two correlated with renal artery stenosis, renal dysfunction and triglycerides. The median glomerular filtration rate was 52.8 mL/min/m². Doppler showed sensitivity of 82.90%, specificity of 70%, a positive predictive value of 85% and negative predictive value of 66.70%. For tomography, sensitivity was 66.70%, specificity 80%, positive predictive value 87.50% and negative predictive value 55.20%. With these findings, we could identify the imaging tests that best detected stenosis.

CONCLUSION

Tomography and Doppler showed good quality and efficacy in the diagnosis of renal artery stenosis, with Doppler having the advantage of not requiring the use of contrast medium for the assessment of a disease that is common in diabetics and is associated with renal dysfunction and severe left ventricular dysfunction.

Evolution of cardiac and renal impairment detected by high-field cardiovascular magnetic resonance in mice with renal artery stenosis

BACKGROUND

Renal artery stenosis (RAS) promotes hypertension and cardiac dysfunction. The 2-kidney, 1-clip mouse model in many ways resembles RAS in humans and is amenable for genetic manipulation, but difficult to evaluate noninvasively. We hypothesized that cardiovascular magnetic resonance (CMR) is capable of detecting progressive cardiac and renal dysfunction in mice with RAS and monitoring the progression of the disease longitudinally.

METHODS

RAS was induced at baseline in eighteen mice by constricting the renal artery. Nine additional animals served as normal controls. CMR scans (16.4 T) were performed in all mice one week before and 2 and 4 weeks after baseline. Renal volumes and hemodynamics were assessed using 3D fast imaging with steady-state precession and arterial spin labelling, and cardiac function using CMR cine. Renal hypoxia was investigated using blood oxygen-level dependent (BOLD) MR.

RESULTS

Two weeks after surgery, mean arterial pressure was elevated in RAS mice. The stenotic kidney (STK) showed atrophy, while the contra-lateral kidney (CLK) showed hypertrophy. Renal blood flow (RBF) and cortical oxygenation level declined in the STK but remained unchanged in CLK. Moreover, cardiac end-diastolic and stroke volumes decreased and myocardial mass increased. At 4 weeks, STK RBF remained declined and the STK cortex and medulla showed development of hypoxia. Additionally, BOLD detected a mild hypoxia in CLK cortex. Cardiac end-diastolic and stroke volumes remained reduced and left ventricular hypertrophy worsened. Left ventricular filling velocities (E/A) indicated progression of cardiac dysfunction towards restrictive filling.

CONCLUSIONS

CMR detected longitudinal progression of cardiac and renal dysfunction in 2K, 1C mice. These observations support the use of high-field CMR to obtain useful information regarding chronic cardiac and renal dysfunction in small animals.

Hyponatremic-hypertensive syndrome: think of unilateral renal artery stenosis

Hyponatremic hypertensive syndrome (HHS) is an uncommon disorder, in which hypertension is associated with profound hyponatremia. It is mostly encountered in adults with unilateral renal artery stenosis. Although renovascular hypertension is one of the commonest causes for severe hypertension in children, HHS is rarely reported in childhood. The authors report a 9-y old boy with hypertensive emergency and severe hyponatremia due to unilateral renal artery stenosis who was successfully managed by vascular stenting of the affected vessel. Prompt recognition of this disorder can be life-saving and can subsequently lead to appropriate referral and treatment as in the present case.

[Clinical characteristics and imaging evaluation in children with renovascular hypertension]

OBJECTIVE

To characterize the clinical and angiographic features in children with renovascular hypertension.

METHOD

Clinical data of 14 children (7 male, 7 female; age 0.8-14 years, mean 8.7 years), who were diagnosed with renovascular hypertension by renal angiography in our institute from January 2005 to December 2012 were collected and retrospectively analyzed.

RESULT

The mean blood pressure at the diagnosis was 187/127 mm Hg. Chief complaints of symptomatic patients were headache (29%, 4/14), hypertensive encephalopathy (36%, 5/14), signs of congestive heart failure (14%, 2/14) and hematemesis (7%, 1/14). Renovascular hypertension was found incidentally in 14% (2/14) of patients who were asymptomatic. Conventional renal angiography elucidated the anatomical distribution of lesions in the renal arterial system. It was found that 14% (2/14) of patients had bilateral disease, 50% (7/14) had single stenosis at main or accessory renal artery, while multiple stenoses was seen in 43% (6/14) of children, with involvement of segmental renal artery and small interlobar or arcuate vessels. Compared with catheter angiography, 50% (7/14) of patients with renovascular hypertension, especially intrarenal arterial disease, were missed on computed tomography angiography or magnetic resonance angiography.

CONCLUSION

It is mandatory to emphasize blood pressure measurement in pediatric clinical practice for early recognition of renovascular hypertension. As children with renovascular hypertension display involvement of multiple arteries, including in smaller intrarenal arteries, digital subtraction angiography is the only method that can reliably diagnose pediatric renovascular hypertension.

[Clinical case of the month. Renovascular arterial hypertension complicated by diabetes insipidus: report of a case and review of the literature]

Mrs. A, a 62 year old patient with a history of hypertension, polyuria and polydipsia is hospitalized after a malaise. A severe hypokalemia, which is the cause of the polyuria and polydipsia, is discovered. The presence of hypertension and hypokalemia arises suspicion of a primary hyperaldosteronism and the plasma levels of renin and aldosterone are measured. Elevated aldosterone levels are combined with high plasma renin concentrations which permits to rule out primary hyperaldosteronism. Further explorations reveal a subocclusive ostial stenosis of the right renal artery. A treatment by sartan is instaured, which allows arterial pressure control and kalemia normalization. Chronic hypokalemia can be the cause of tubular nephropathy manifested by nephrogenic diabetes insipidus.

Late renal artery occlusion following endovascular repair of abdominal aortic aneurysm: a possible complication of mural thrombus formation within aortic endografts

Mural thrombus formation within aortic endoprostheses has been described to occur in up to one-third of aortic endografts depending on the device type. Data regarding the clinical significance of such a phenomenon are scarce, but in most cases it is considered to be clinically innocent. The authors describe a rare case of late renal artery occlusion due to intraprosthetic thrombus formation and extension into the right renal orifice 30 months after endovascular abdominal aortic aneurysm repair. Additionally, a brief literature review regarding the incidence and natural history of mural thrombotic deposits within aortic endografts is also conducted.

Ischemic nephropathy: more than a simple renal artery narrowing

Renal artery stenosis in elderly patients is mainly caused by atherosclerosis. The prevalence of this disorder in patients with chronic kidney diseases is reported to be 0.5% to 5.5%. However, because the patients with atherosclerotic renal artery disease are mostly asymptomatic, the true prevalence is expected to be higher. Renovascular hypertension and ischemic nephropathy are two main consequences of this disease, but it is difficult to determine in which patient the progress of stenosis may cause these syndromes. The big challenge in renal artery stenosis is how to manage the patients. In the past 70 years, it has been believed that simply maintaining of kidney perfusion by opening the stenosis could control blood pressure and preserve kidney function. Nowadays, the blood pressure can be controlled well by medical treatment without the need for revascularization; however, management of ischemic nephropathy remains a dilemma. With advancements in understanding the pathophysiology of changes in the parenchyma of the kidney after stenosis, it is now generally accepted that only a minority of patients with ischemic nephropathy will benefit from revascularization. Nonetheless, finding these patients is critical and need more randomized trials to show who mostly benefit from revascularization and when it may save the kidney.

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.

Hyponatremic hypertensive syndrome in pediatric patients: is it really so rare?

BACKGROUND

Hyponatremic hypertensive syndrome (HHS) is characterized by unilateral renal artery stenosis with secondary hypertension and glomerular and tubular dysfunction due to hyperfiltration and activation of the renin-angiotensin system (RAS).

CASE-DIAGNOSIS/TREATMENT

We describe four children with HHS. All presented with polyuria and polydipsia, electrolyte disturbances, metabolic alkalosis, variable tubular dysfunction, and nephrotic range proteinuria along with hypertension. Interestingly, in one patient, glomerular and tubular abnormalities preceded the development of hypertension. All symptoms resolved after the underlying renal ischemia was corrected by percutaneous angioplasty.

CONCLUSION

Hyponatremic hypertensive syndrome may be more common in children than previously thought. Clinicians should be alert of the signs and symptoms because cure is possible with timely diagnosis and treatment.

Time-resolved MR angiography of renal artery stenosis in a swine model at 3 Tesla using gadobutrol with digital subtraction angiography correlation

PURPOSE

To establish the minimum dose required for detection of renal artery stenosis using high temporal resolution, contrast enhanced MR angiography (MRA) in a porcine model.

MATERIALS AND METHODS

Surgically created renal artery stenoses were imaged with 3 Tesla MR and digital subtraction angiography (DSA) in 12 swine in this IACUC approved protocol. Gadobutrol was injected intravenously at doses of 0.5, 1, 2, and 4 mL for time-resolved MRA (1.5 × 1.5 mm(2) spatial resolution). Region of interest analysis was performed together with stenosis assessment and qualitative evaluation by two blinded readers.

RESULTS

Mean signal to noise ratio (SNR) and contrast to noise ratio (CNR) values were statistically significantly less with the 0.5-mL protocol (P < 0.001). There were no statistically significant differences among the other evaluated doses. Both readers found 10/12 cases with the 0.5-mL protocol to be of inadequate diagnostic quality (κ = 1.0). All other scans were found to be adequate for diagnosis. Accuracies in distinguishing between mild/insignificant (<50%) and higher grade stenoses (>50%) were comparable among the higher-dose protocols (sensitivities 73-93%, specificities 62-100%).

CONCLUSION

Renal artery stenosis can be assessed with very low doses (~0.025 mmol/kg bodyweight) of a high concentration, high relaxivity gadolinium chelate formulation in a swine model, results which are promising with respect to limiting exposure to gadolinium based contrast agents.