Outcomes after stenting of renal artery stenosis in patients with high-risk clinical features.

BACKGROUND: In patients with renal artery stenosis, revascularization was seen as a mean to improve outcomes, but large studies failed to show significant benefit in general population. However, data on benefits of renal artery stenting in patients with high-risk features, such as rapidly declining renal function and cardiac destabilization syndromes, are limited, as they were excluded from trials. In this descriptive study, we aimed to evaluate short- and long-term outcomes in high-risk patients with renal artery stenosis, treated by angioplasty and stenting. We have retrospectively interrogated our local databases for renal artery percutaneous interventions; patients at high-risk (rapidly declining renal function; stable chronic renal failure and bilateral renal artery disease; severe hypertensive crisis) were selected for the current analysis. RESULTS: Of 30 patients undergoing renal artery stenting, 18 patients were deemed "high-risk." On short term, good in-hospital control of hypertension and cardiac stabilization were obtained in all patients. Renal function improved significantly only in patients admitted with rapidly declining renal function, with significant creatinine level fall from median 3.98 mg/dL to 2.02 mg/dL, p = 0.023. However, for the whole group, creatinine change was non-significant (- 0.12 mg/dL, p = NS). On the long term, five patients (27.8%) ended-up on chronic hemodialysis and six patients died (33.3%) after a median of 20 months. No death occurred during the first year after the procedure. CONCLUSIONS: Percutaneous procedures are feasible and safe in patients with high-risk renal artery stenosis, especially in those with rapidly declining renal function, probably saving some of them from the immediate need for renal replacement therapy, but long-term results are negatively influenced by the precarious general and cardio-vascular status of these patients and by the pre-existing significant renal parenchymal disease, non-related to the renal artery stenosis.

Endovascular treatments of atherosclerotic renovascular disease: a narrative review and literature search.

In recent years, endovascular treatments have become more common in patients with renal artery stenosis and aneurysm. Although the treatment algorithms are not universally accepted, endovascular therapy can be readily utilized for the appropriate indications in the context of surgical treatment for renovascular diseases. The most important factor to consider is that the correct indication is applied for such treatment. Although the applied procedures are believed to have minimal risk, any complications that occur may result in major problems. Moreover, the pathology that is being treated (e.g., hypertension, high serum creatinine concentration, or low glomerular filtration rate) must be well defined. As stent and balloon technologies continue to be developed, more positive results are expected in the coming years. In the present study, we reviewed the endovascular treatment algorithms for atherosclerotic renovascular disease and performed a narrative review of the current literature.

Urgent endovascular maneuvers to rescue a failing transplant kidney with a T-stent approach.

Renal artery thrombosis (RAT) is a major cause of renal transplant loss and, for this reason, should be treated promptly. We present a case of a 48-year-old man with external iliac thrombosis associated with thrombosis of a transplant renal artery that led to worsening of renal function. Multiple mechanisms have been identified in the literature as risk factors for RAT. In our patient, a combination of anastomotic stenosis, hypercoagulability, and diabetic nephropathy had resulted in RAT, and an unconventional endovascular revascularization technique with a T-stent approach was needed to guarantee patency of the treated vessels. No 30-day perioperative complications occurred, and the postoperative follow-up examination showed patency of the treated vessels; thus, transplant loss was avoided.

Predicting renal function response to renal artery stenting.

OBJECTIVE: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions Trial found no benefit of renal artery stenting (RAS) over medical therapy, although it was underpowered to detect a benefit among patients with chronic kidney disease (CKD). A post hoc analysis demonstrated improved event-free survival after RAS for patients whose renal function improved by 20% or more. A significant obstacle to achieving this benefit is the inability to predict which patients' renal function will improve from RAS. The objectives of the current study were to identify predictors of renal function response to RAS. METHODS: The Veteran Affairs Corporate Data Warehouse was queried for patients who underwent RAS between 2000 and 2021. The primary outcome was improvement in renal function (estimated glomerular filtration rate [eGFR]) after stenting. Patients were categorized as responders if the eGFR at 30 days or greater after stenting increased by 20% or more compared with before stenting. All others were nonresponders. RESULTS: The study cohort included 695 patients with a median follow-up of 7.1 years (interquartile range, 3.7-11.6 years). Based on postoperative change in eGFR, 202 stented patients (29.1%) were responders, and the remainder (n = 493 [70.9%]) were nonresponders. Before RAS, responders had a significantly higher mean serum creatinine, lower mean eGFR, and higher rate of decline of preoperative GFR in the months before stenting. After stenting, responders had a 26.1% increase in eGFR, compared with before stenting (P < .0001), which remained stable during follow-up. In contrast, nonresponders had a progressive 5.5% decrease in eGFR after stenting. Logistic regression analysis identified three predictors of renal function response to stenting: (1) diabetes (odds ratio [OR], 0.64; 95% confidence interval [CI], 0.44-0.91; P = .013), (2) CKD stages 3b or 4 (OR, 1.80; 95% CI, 1.26-2.57; P = .001), and (3) rate of decline in preoperative eGFR per week before stenting (OR, 1.21; 95% CI, 1.05-1.39; P = .008). CKD stages 3b and 4 and the rate of decline in preoperative eGFR are positive predictors of renal function response to stenting, whereas diabetes is a negative predictor. CONCLUSIONS: Based on our data, patients in CKD stages 3b and 4 (eGFR 15-44 mL/min/1.73 m2) are the only subgroups with a significant probability of improved renal function after RAS. The rate of decline of preoperative eGFR over the months before stenting is a powerful discriminator of patients who are most likely to benefit from RAS. Specifically, patients with a more rapid decrease in eGFR before stenting have a significantly greater probability of improved renal function with RAS. In contrast, diabetes is a negative predictor of improved renal function, so interventionalists should be circumspect about RAS in diabetic patients.

Transradial Renal Angioplasty and Stent Placement for Systemic Hypertension Caused by Severe Unilateral Renovascular Stenosis.

Percutaneous transluminal angioplasty and stent placement for renovascular hypertension is a recognized albeit seldom used therapy. We present a case of severe renovascular hypertension, due to renal artery atherosclerosis, treated successfully with stent placement via the radial artery access approach.

Retrieval of renal function after renal artery stenting improves event-free survival in a subgroup analysis of the Cardiovascular Outcomes in Renal Atherosclerotic Lesions trial.

OBJECTIVE: The Cardiovascular Outcomes in Renal Atherosclerotic Lesions (CORAL) trial, a multicenter randomized controlled trial with 947 patients, concluded that there was no benefit of renal artery stenting (RAS) over medical therapy. However, patients with chronic kidney disease (CKD) were not analyzed separately in the CORAL trial. CKD is a risk factor for cardiovascular and renal morbidity. We hypothesized that improved renal function after RAS would be associated with increased long-term survival and a lower risk of cardiovascular and renal events in patients with CKD. METHODS: This post hoc analysis of the CORAL trial included 842 patients with CKD stages 2 to 4 at baseline who were randomized to optimal medical therapy alone (OMT; n = 432) or RAS plus OMT (RAS + OMT; n = 410). Patients were categorized as responders or nonresponders based on the change in the estimated glomerular filtration rate (eGFR) from baseline to last follow-up (median, 3.6 years; interquartile range, 2.6-4.6 years). Responders were defined by a 20% or greater increase in eGFR from baseline; all others were designated as nonresponders. Event-free survival was defined as freedom from death and multiple cardiovascular and renal complications. Event-free survival was analyzed using the Kaplan-Meier method and log-rank test. Multivariable Cox proportional hazards regression analysis was used to identify independent predictors of event-free survival. RESULTS: The RAS + OMT group had a higher proportion of patients with improved renal function (≥20% increase in eGFR over baseline), compared with the OMT group (25.6% vs 17.1%; P = .003). However, event-free survival was no different for the two cohorts (P = .18 by the log-rank test). Multivariable Cox proportional hazards regression analysis identified four variables that independently correlated with event-free survival for the stented cohort. Higher preoperative eGFR (hazard ratio, 0.98; 95% confidence interval [CI], 0.96-0.99; P = .002) and being a responder to stenting (hazard ratio, 0.49; 95% CI, 0.26-0.95; P = .033) increased event-free survival, whereas a history of congestive heart failure (hazard ratio, 2.52; 95% CI, 1.46-4.35; P < .001) and a higher preoperative systolic BP (hazard ratio, 1.02; 95% CI, 1.01-1.03; P = .002) decreased event-free survival. Within the stented group, 105 of 410 patients (25.6%) were responders. Event-free survival was superior for responders, compared with nonresponders (P = .009 by log-rank test). The only independent preoperative negative predictor of improved renal function after stenting was diabetes (odds ratio, 0.37; 95% CI, 0.16-0.84; P = .017), which decreased the probability of improved renal function after RAS + OMT. A subset of patients (23.4%) after RAS had worsened renal function, but OMT alone produced an equivalent incidence of worsened renal function. An increased urine albumin/creatinine ratio was an independent predictor of worsened renal function after RAS. CONCLUSIONS: CORAL participants who demonstrated improved kidney function after RAS + OMT demonstrated improved event-free survival. This finding reinforces the need for predictors of outcome to guide patient selection for RAS.

Percutaneous transluminal renal artery stenting using digital subtraction angiography with diluted contrast medium in a patient with severe chronic kidney disease.

Atherosclerotic renal artery stenosis (ARAS) is associated with ischemic nephropathy, kidney failure, and secondary hypertension. Percutaneous transluminal renal artery stenting (PTRAS) is required for patients with hemodynamically significant ARAS. However, PTRAS can be problematic in patients with chronic kidney disease (CKD) because the use of a large amount of iodinated contrast medium is associated with an increased risk of contrast-induced nephropathy. We describe a case of PTRAS with successful revascularization by using digital subtraction angiography (DSA) with diluted contrast medium (1:10 dilution). An 89-year-old man with resistant hypertension and CKD was hospitalized in our institution for acute coronary syndrome. During hospitalization, the patient's blood pressure was extremely high (180-200/70-90 mmHg), despite the use of four antihypertensive agents. We examined the cause of hypertension and detected significant right renal artery stenosis and left kidney atrophy with renal artery obstruction. We performed PTRAS on the right renal artery by using DSA with a diluted contrast medium. Revascularization was successful using only 3 mL of the contrast medium. PTRAS using DSA with diluted contrast medium can be an effective technique for treating ARAS in patients with CKD to preserve renal function. Learning objectives: Atherosclerotic renal artery stenosis (ARAS) is associated with ischemic nephropathy, kidney failure, and secondary hypertension. Percutaneous transluminal renal artery stenting (PTRAS) is required for patients with hemodynamically significant ARAS. However, PTRAS can be problematic in patients with chronic kidney disease because of the increased risk of contrast-induced nephropathy. We describe a technique of PTRAS using digital subtraction angiography with a diluted contrast medium to achieve a successful revascularization.

Acute Embolic Occlusion of Renal Artery after the Bentall Procedure: the Role of Primary Renal Angioplasty.

Acute renal occlusion is an uncommon emergency problem in daily practice. The diagnosis is often missed or delayed not only because of its rarity but also nonspecific of clinical presentation. Sudden and complete termination of arterial blood supply to the kidney may lead to renal infarction and a complete loss of renal function. Although the need of early revascularization is uniformly recommended, but the methods has not been established. We presented a case of acute thromboembolic renal artery occlusion in patient who had a history of Bentall's surgery. Renal infarction and artery occlusion were clearly visualized by computed tomography angiogram (CTA). The patient was successfully treated with angioplasty and stenting of main renal artery with complete disappearance of symptoms and recovery of his renal function.

Revascularization for controlling hypertension and improving cardiorenal failure in Leriche syndrome.

Leriche syndrome usually occurs when atherosclerotic obstructions result in luminal narrowing of the abdominal aorta or iliac arteries and leads to thrombosis; it rarely causes heart or renal failure. We report the case of a 58-year-old Asian man with heart and renal failure as the dominant clinical manifestations of renovascular hypertension caused by Leriche syndrome. We performed an aorto-bifemoral bypass and unilateral renal artery stenting. Post-operative echocardiography showed improved cardiac function, with the left ventricular ejection fraction increasing from 30% before surgery to 54.2% after surgery. Moreover, his heart rate and blood pressure became stable, and his serum creatinine and brain natriuretic peptide levels decreased from 3.46 to 1.08 mg/dL and 685 to 4 pg/mL, respectively. Our case report shows that aorto-bifemoral bypass and unilateral renal artery stenting can effectively treat heart and renal failure resulting from renovascular hypertension caused by Leriche syndrome.

Prediction of Split Renal Function Improvement After Renal Artery Stenting by Blood Oxygen Level-Dependent Magnetic Resonance Imaging.

Background: The discrepancy between the high technical success rate and the relatively low clinical response rate of renal artery stenting (RAS) raises the importance to identify atherosclerotic renal artery stenosis (ARAS) patients who are most likely to benefit from RAS. This study aimed to investigate the feasibility and accuracy of blood oxygen level-dependent magnetic resonance imaging (BOLD-MRI) in predicting split renal function (SRF) improvement after RAS in patients with ARAS. Methods: Thirty patients with severe ARAS who were treated with RAS were enrolled. Baseline cortical and medullary R2* values of each kidney were measured by BOLD-MRI, and each patient's SRF was evaluated by nuclear renal dynamic imaging at baseline and 1-month follow-up. Results: In total, 35 severe stenotic renal arteries of the 30 patients were analyzed. At 1-month follow-up, 34 kidneys (97.1%) of severe ARAS had acquired SRF. SRF improved in 12 kidneys of 10 patients. The cortical R2* and medullary R2* values in the SRF improvement kidneys were higher than those in the non-improvement kidneys (P ≤ 0.001). The area under the curve of medullary R2* was 0.879 (95% confidence interval [CI] 0.736-1.000). A medullary R2* value ≥29.1 s-1 was noted to provide good sensitivity (0.833, 95% CI 0.552-0.970) and specificity (0.864, 95% CI 0.667-0.953) in predicting SRF improvement. Medullary R2* value was the only independent predictor of SRF improvement in multivariable analysis (P = 0.034, OR 3.017, 95%CI 1.089-8.358). Conclusion: This study showed that a BOLD-MRI medullary R2* value ≥29.1 s-1 was an excellent predictor of SRF improvement in patients with severe ARAS who underwent renal artery stenting.

Renal artery revascularization is a controversial treatment strategy for renal artery stenosis: A case series and a brief review of the current literature.

Renal artery stenosis (RAS) may cause secondary hypertension, progressive decline in renal function, and cardiac destabilization syndromes including "flash" pulmonary edema, recurrent congestive heart failure, and cerebro-cardiovascular disease. Atherosclerotic lesions, fibromuscular dysplasia, and vasculitides are the pathophysiological basis of the disease. Common therapeutic pathways for RAS include medical therapy and revascularization with or without stenting. Randomized controlled trials evaluating renal revascularization have not reported any advantages of revascularization over medical therapy alone in terms of renal function improvement or prevention of cardiovascular events. However, mounting clinical experience suggests that the best strategy in RAS management is to identify which patients are most likely to benefit from renal artery stenting and to optimize the safety and durability of the procedure. This review presents 3 cases of patients who have undergone renal revascularization and discusses the available clinical evidence for the identification of RAS patients who will potentially respond well to revascularization.

Salvage from hemodialysis via percutaneous transluminal renal artery stenting for a jeopardized solitary functioning kidney: A case report.

Atherosclerotic renal artery stenosis (ARAS) causes resistant hypertension, progressively declining renal function, and cardiac destabilization syndromes, including heart failure. We report a patient who underwent successful percutaneous transluminal renal angioplasty (PTRA) for anuretic acute kidney injury (AKI) due to ARAS. This patient, admitted to our hospital with congestive heart failure, developed anuretic AKI and started hemodialysis 3 days after admission. Computed tomography and magnetic resonance angiograms showed total occlusion of the proximal right renal artery, with atrophy of the right kidney and severe stenosis of the proximal left renal artery. These findings suggested that only the left kidney was functioning. We performed PTRA of the left renal artery in which the culprit lesion causing the AKI appeared to be located. Using intravascular ultrasound, severe calcification in the ostium of the left renal artery and a necrotic core with plaque rupture in the culprit lesion were observed. Kidney function recovered immediately after revascularization, which permitted successful withdrawal of hemodialysis. There is no clear consensus regarding the indication for PTRA in patients with ARAS; however, our experience suggests that PTRA may be beneficial for patients with a jeopardized solitary functioning kidney. .

Determinant role of renal artery stenting in recovery from acute worsening of atherosclerotic renal failure.

Because previous randomized clinical trials have failed to show any benefits of renal artery stenting (RAS), clinicians have been confused regarding the optimal management of patients with atherosclerotic renal artery stenosis (ARAS). Here, we report a notable case with ARAS whose clinical course could help clinicians identify patients suitable for RAS. A 66-year-old woman with ARAS and some parameter abnormalities on renal duplex ultrasound was admitted to our hospital with severe hypertension (>250 mmHg). After the initiation of antihypertensive intravenous treatment, the patient manifested acute worsening of renal function over 6 days and required dialysis. Because renal failure continued to deteriorate over more than 4 weeks, we performed stenting to the severe ostial stenosis of the right renal artery. As a result, the patient achieved dramatic improvement in renal function and successful withdrawal from dialysis and has maintained stable control of blood pressure without additional events for more than 2 years since discharge. This case suggests that careful analysis of the patient's profile, such as history of rapidly deteriorating renal failure, presence of bilateral ARAS, or a solitary functional kidney, in addition to various parameters of renal duplex ultrasound, may help predict the efficacy of RAS in patients with ARAS. .

Is the Renal Resistive Index a Marker for Revascularization in Atherosclerotic Renal Artery Stenosis?

Renal artery stenosis (RAS) is one of the major causes of resistant/malignant hypertension. It can be described as atherosclerotic or non-atherosclerotic. Atherosclerotic RAS comprises almost 90% of all RAS cases and is a prevalent disease of the elderly. Multiple risk factors contribute to atherosclerosis development, which leads to the release of renin and aldosterone, causing resistant/malignant hypertension. Early recognition is prudent but challenging as there are no early clinical signs. We believe that renal resistive index with supportive clinical, laboratory, and imaging modalities can help select revascularization patients.

Long-Term Mortality After Renal Artery Stenting in Patients With Severe Atherosclerotic Renal Artery Stenosis and High-Risk Clinical Manifestations.

BACKGROUND: Atherosclerotic renal artery stenosis is a risk factor for cardiovascular death. Observational studies support the benefit of renal revascularization on outcomes in patients with high-risk clinical manifestations. In this context, we evaluated the factors associated with long-term mortality after renal artery stenting in patients with severe renal artery stenosis, impaired kidney function, and/or uncontrolled hypertension. METHODS: The medical records of patients undergoing renal artery stenting between 2004 and 2014 were extracted. Blood pressure and creatinine were recorded at baseline, 24 hours poststenting and in the 1-month to 1-year interval that followed revascularization. Long-term follow-up was performed in March 2020. RESULTS: The cohort consisted of 65 patients. Median follow-up was 120 months. In the first year after stenting, less patients had chronic kidney disease (CKD) class 3b-5 as compared with baseline (35.3% vs. 56.9%, P = 0.01). The number of patients with controlled blood pressure after revascularization increased with 69.2% (P < 0.001). Long-term all-cause mortality reached 44.6%. Age (odds ratio (OR) 1.1; 95% confidence interval (CI) 1.0-1.2; P = 0.01), male gender (OR 7.9; 95% CI 1.9-43.5; P = 0.008), poststenting CKD class 3b-5 (OR 5.8; 95% CI 1.5-27.9; P = 0.01), and postrevascularization uncontrolled hypertension (OR 8.9; 95% CI 1.7-63.5; P = 0.01) were associated with long-term mortality independent of diabetes mellitus and coronary artery disease. CONCLUSIONS: Improved CKD class and blood pressure were recorded in the first year after renal artery stenting in patients with severe renal artery stenosis and high-risk clinical manifestations. The lack of improvement in kidney function and blood pressure was independently associated with long-term mortality.

Successful Retrieval of a Stuck Guidewire by Guiding Catheter Lock Technique in Renal Artery Stenting.

INTRODUCTION: The guiding catheter lock technique is a therapeutic technique to increase backup force of the guiding catheter in coronary artery interventions. SURGICAL TECHNIQUE: A 71 year old man presented with rapidly declining kidney function resulting from bilateral renal artery stenosis. During the renal artery stenting procedure, the 0.014" guidewire became trapped at the stent's distal edge. Although attempts were made to advance a microcatheter and balloon catheter over the trapped guidewire, these failed because of insufficient pushability of the guiding catheter. Therefore, the guiding catheter lock technique was used with a second guiding catheter, and the guidewire was successfully retrieved. DISCUSSION: The guiding catheter lock technique facilitated strong pushability to allow for successful retrieval of a stuck guidewire during renal artery stenting.

Intra-Arterial Hemodynamics to Guide the Percutaneous Treatment of a Difficult-to-Engage Transplant Renal Artery Stenosis.

Transplant renal artery stenosis (TRAS) is the most frequent vascular complication after renal transplantation. TRAS is associated with resistant hypertension and allograft dysfunction, early diagnosis and either endovascular or surgical treatment is crucial to preserve graft function. Noninvasive imaging can usually detect the underlying stenosis. In this report we present a novel technique for successful angioplasty and stent deployment in a difficult-to-engage transplant-renal artery.

Renal Artery Stenosis in the Patient with Hypertension: Prevalence, Impact and Management.

Atherosclerosis is the primary cause of renal artery stenosis. Atherosclerotic renal artery stenosis (ARAS) is associated with three clinical problems: renovascular hypertension, ischemic nephropathy and cardiac destabilization syndrome which pose huge healthcare implications. There is a significant rate of natural disease progression with worsening severity of renal artery stenosis when renal revascularization is not pursued in a timely manner. Selective sub-groups of individuals with ARAS have had good outcomes after percutaneous renal artery stenting (PTRAS). For example, individuals that underwent PTRAS and had improved renal function were reported to have a 45% survival advantage compared to those without improvement in their renal function. Advances in the imaging tools have allowed for better anatomic and physiologic measurements of ARAS. Measuring translesional hemodynamic gradients has allowed for accurate assessment of ARAS severity. Renal revascularization with PTRAS provides a survival advantage in individuals with significant hemodynamic renal artery stenosis lesions. It is important that we screen, diagnosis, intervene with invasive and medical treatments appropriately in these high-risk patients.

[In-hospital results of renal artery stenting in patients with multifocal atherosclerosis]. / Gospital'nye rezul'taty stentirovaniia pochechnykh arterii u patsientov s mul'tifokal'nym aterosklerozom.

OBJECTIVE: A retrospective analysis of in-hospital results of renal artery stenting in patients with multifocal atherosclerosis. MATERIAL AND METHODS: The study included 19 patients who underwent stenting for renal artery stenosis for the period 2011-2015 in the Kemerovo Cardiology Dispensary. Renal function was assessed considering glomerular filtration rate (GFR). Blood pressure and GFR were evaluated before the stenting procedure and at discharge. RESULTS: Stenting resulted optimal outcomes in all 19 patients. Severity of residual stenosis was 11±3%. In-hospital mortality was absent. Blood pressure in early postoperative period was similar to baseline values. One patient had a normalization of blood pressure up to 115-140/85-90 mm Hg without administration of antihypertensive drugs. Decrease of systolic blood pressure up to 155.3±32.6 mm Hg was noted in other patients at discharge. Blood creatinine levels decreased up to 0.167±0.56 mmol/L. In addition, mean GFR increased from 34.17 ml/min/1.69 m2 up to 37.16 ml/min/1.69 m2. CONCLUSION: Endovascular treatment of renal artery stenosis and secondary hypertension is effective and relatively safe approach.