Significant Renal Artery Stenosis Research Articles

Assessment of renal artery stenosis using renal fractional flow reserve and correlation with angiography and color Doppler ultrasonography: data from FAIR-pilot trial.

Renal fractional flow reserve (rFFR), a hemodynamic evaluation indicator for functional measurement, could be used for the detection of significant renal artery stenosis (RAS). In this study, we evaluated the correlation between color Doppler ultrasonography (CDU), angiography and rFFR in assessing RAS and to validate cut-off points of ultrasound parameters for significant RAS with rFFR<0.8. A total of 77 renal artery lesions from 58 patients with at least unilateral RAS were included into this study. All patients were participated in Fractional Flow Reserve to Determine the Appropriateness of Percutaneous Renal Artery Intervention in Atherosclerosis Renal Hypertension Patients (FAIR)-pilot study (NCT05732077). The rFFR was measured through a pressure wire after renal hyperemia induced by dopamine. Peak systolic velocity (PSV), renal-to-aortic ratio (RAR), resistive index (RI) and side-to-side differences of the intrarenal resistive indices (ΔRI) were obtained by CDU. The rFFR showed good correlation with both CDU and angiography assessment methods. Among CDU parameters, the best correlation was observed in rFFR with PSV (rho = -0.668, P < 0.0001) and RAR (rho = -0.597, P < 0.001). With a rFFR<0.80 as cut-off value for significant RAS, we computed sensitivity, specificity, and area under the curve (AUC) of CDU parameters. The most predicting cut-off points of CDU parameters were calculated as PSV for 2.415 m/s, RAR for 4.495, RI for 0.605 and ΔRI for 0.04, respectively. A PSV > 2.415 m/s provided a sensitivity of 90%, specificity of 75%, accuracy of 81% and AUC of 0.84 for detecting RAS with rFFR<0.8.

Atherosclerotic Renal Arterial Stenosis with Multivascular Involvement in a Patient Presenting with Uncontrolled Hypertension and Cardiac Dysfunction

Renal artery stenosis (RAS) is the most common cause of secondary hypertension, with an incidence rate of 1–3% and atherosclerosis being the most common cause in 90% of the cases. The detection of atherosclerotic RAS may portend multivascular involvement; hence, a more comprehensive approach is essential. Clinical outcomes depend on renal condition and atherosclerotic burden with other coexisting cardiovascular diseases. A haemodynamically significant RAS can be considered with the onset of hypertensive crisis associated with worsening renal function and flash pulmonary oedema, known as Pickering syndrome. Despite the current controversy regarding the lack of randomised studies supporting the benefits of revascularisation over medical therapy, this may be considered in patients with RAS and Pickering syndrome. Reported here is the case of a 76-year-old woman with bilateral RAS who presented with persistent elevated blood pressure and heart failure symptoms. The patient underwent successful bilateral percutaneous transluminal renal angioplasty. Long-term monitoring requires maintaining adequate blood pressure control and renal function.

Prevalence and Risk Factors of Renal Artery Stenosis in Patients Undergoing Simultaneous Coronary and Renal Artery Angiography: A Systematic Review and Meta-Analysis of 31,689 Patients from 31 Studies.

Background/Objectives: Renal artery stenosis (RAS) is associated with coronary artery disease (CAD), exacerbation of arterial hypertension, and progression to heart failure, but remains frequently unrecognized in clinical practice. Methods: We conducted a systematic review and meta-analysis of studies by pooling data of patients undergoing CAG due to suspected or stable CAD that received a bilateral renal artery angiography. Results: A total of 31 studies with 31,689 patients were included (mean age 63.2 ± 8.7 years, 20.9% were female). Overall, 13.4% (95%CI 10.5-16.7%) of patients undergoing coronary angiography had significant RAS, with 6.5% (95% CI 4.5-8.9%) and 3.7% (95%CI 2.5-5.2%) having severe and bilateral RAS. The mean weighted proportion of patients with three-vessel coronary disease (3VD) was 25.1 (95%CI 19.6-30.9%) while 4.2% (95%CI 2.6-6.2%) had left main (LM) coronary disease. Patients with RAS compared to those without RAS were significantly older (mean difference, MD 4.2 years (95%CI 3.8-4.6)). The relative risk of RAS was greater for the female sex (risk ratio, 95%CI; RR 1.3, 1.03-1.57), presence of diabetes (RR 1.2, 1.10-1.36), arterial hypertension (RR 1.3, 1.21-1.46), dyslipidemia (RR 1.1, 1.06-1.14), peripheral artery disease (PAD) (RR 2.1, 1.40-3.16), chronic kidney disease (CKD) (RR 2.6, 2.04-3.37), 3VD (RR 1.6, 1.30-1.87), and LM disease (RR 1.8, 1.28-2.47). Smoking had a neutral effect on the risk of RAS occurrence (RR 1.0, 0.94-1.06). Conclusions: RAS is common in patients undergoing coronary angiography. CKD, PAD, older age, and severe CAD were among the strongest predictors for the presence of significant RAS.

Treatment of renal artery fibromuscular dysplasia with drug-eluting balloon angioplasty and intravascular imaging: a case report

Fibromuscular dysplasia (FD) is a segmental, non-inflammatory and non-atherosclerotic disease of vascular smooth muscle of unknown etiology, which leads to stenosis of smalland medium-sized arteries. The choice of surgical treatment tactics for renal artery FD depends on the severity of clinical manifestations and the response to the conservative drug treatment used. Young age, female sex, high blood pressure with failure to achieve target values with therapy, as well as the absence of atherosclerotic involvement of other arterial systems gives reason to suspect renal artery FD. According to modern guidelines, the invasive treatment of hemodynamically significant renal artery stenoses includes transluminal drug-eluting balloon angioplasty. In this disease, renal artery stenting is not recommended. However, stent implantation is required if balloon angioplasty did not give the optimal result or in case of periprocedural complications, such as arterial dissection. Open reconstructive surgery is indicated for complex anatomy of the related artery, macroaneurysms in which stent grafts are ineffective, refractory intimal fibroplastic lesions, increased risk of endovascular treatment, or after unsuccessful endovascular intervention. The article presents a case of a young patient with renal artery FD, renovascular arterial hypertension, who successfully underwent renal artery transluminal drugeluting balloon angioplasty.

Ten-Year Outcomes in Patients Undergoing Simultaneous Coronary and Renal Angiography-Does Renal Artery Stenosis Matter?

Background: We aimed to characterize the population of consecutive patients undergoing coronary angiography with simultaneous renal artery angiography and assess prognostic factors at a 10 year follow-up. Methods: The KORONEF study was a prospective, single-center, observational, and descriptive study with 492 patients included. We analyzed several baseline demographics, clinical and periprocedural characteristics, and laboratory data, and we assessed the results of coronary angiography and renal artery angiography. Results: The study population consisted of 37.2% women, and the mean age was 64.4 ± 9.9 years (min. 30 years, max. 89 years). Angiography revealed significant renal artery stenosis (RAS) in 35 (7.1%) patients. Among patients with significant RAS (≥50%), we observed more women (57.1% vs. 35.7%, p = 0.011), and patients were older (69.1 ± 10.4 years vs. 64.0 ± 9.7 years, p = 0.005). In the whole population, all-cause death was reported in 29.9% of patients, myocardial infarction (MI) rate-in 11.8%, and stroke-in 4.9%. In the multivariable analysis, independent predictors of death were age 65-75 years (HR 2.88), age > 75 years (HR 8.07), diabetes (HR 1.59), previous MI (HR 1.64), chronic kidney disease (HR 2.22), unstable angina (HR 0.37), and left ventricular ejection fraction > 60% (HR 0.43). Conclusions: Over a 10 year follow-up, the all-cause death rate was 29.9%, showing no statistically significant differences between patients with and without significant RAS.

Оценка чувствительности методов диагностики в выявлении гемодинамически значимых односторонних стенозов почечных артерий

Objective. Assessment of renal artery stenosis significance in patients with resistant arterial hypertension using non-invasive diagnostic methods and to compare them with the results of selective angiography and methods of physiological assessment of renal artery stenoses.Materials and methods. Prospectively, 156 patients with drug-resistant arterial hypertension and signs of renal artery stenosis detected by doppler ultrasonography of renal arteries were included in the study. Subsequently, 25 patients were excluded from the study due to multiple variant renal blood supply and bilateral renal artery stenosis. The remaining patients (n=131) underwent selective angiography of renal arteries, and 66 of them additionally underwent CTA of renal arteries with intravenous contrast. If the artery narrowing was 90% or more (n=27) in diameter, the stenosis was considered hemodynamically significant and further stenting of the affected artery was performed, and in case of 60-90% stenosis (n=52) additional assessment of functional significance of the stenosis was performed by measuring translesional pressure gradient, fractional blood flow reserve, instantaneous blood flow reserve (iFR) and Pd/ Pa ratio. Results. Among all patients (n=131), in whom the doppler ultrasonography of renal arteries showed signs of unilateral renal artery stenosis, after angiography combined with additional methods of functional significance assessment, hemodynamically significant renal artery stenosis was confirmed in 41% of cases (n=54). Thus, the sensitivity of doppler ultrasonography of renal arteries in detection of hemodynamically significant stenoses was 74%, prognostic value of positive 78% and negative result 64% (p&lt;0,001). According to CTA (n=66) renal artery stenosis was confirmed in 56 patients. The results of CTA of renal arteries in 88% of cases coincided with the results of selective angiography, and using additional functional methods hemodynamically significant stenosis was confirmed in 32 (48%) patients. The sensitivity of CTA in detection of hemodynamically significant stenoses of renal arteries was 69%, specificity 91%, prognostic value of positive and negative results was 91 and 68% respectively. According to selective angiography, out of 131 patients, 24 patients had no renal artery stenosis, 28 patients had stenosis &lt;60%, 27 patients had renal artery stenosis &gt;90% and 52 patients had stenosis 60-90%. Patients with stenosis &lt;60% were not considered candidates for renal artery stenting.

Improving outcomes in atherosclerotic renovascular disease: importance of clinical presentation and multi-disciplinary review

Background and objectivesAtherosclerotic renal artery stenosis may cause hypertension, chronic kidney disease and heart failure, but large randomized control trials to date have shown no major additional benefit of renal revascularization over optimal medical management. However, these trials did not consider outcomes specifically in relation to clinical presentations. Given that atherosclerotic renal artery stenosis is a heterogenous condition, measures of success likely differ according to the clinical presentation. Our retrospective study objectives were to determine the effects of revascularization when applied to specific clinical presentations and after careful multi-disciplinary team review.MethodsAll patients presenting to our centre and its referring hospitals with radiological findings of at least one renal artery stenosis > 50% between January 2015 and January 2020 were reviewed at the renovascular multi-disciplinary team meeting with revascularization considered in accordance with international guidelines, notably for patients with anatomically significant renal artery stenosis, adequately sized kidney and presentations with any of; deteriorating kidney function, heart failure syndrome, or uncontrollable hypertension. Optimal medical management was recommended for all patients which included lipid lowering agents, anti-platelets and anti-hypertensives targeting blood pressure ≤ 130/80 mmHg. The effect of revascularization was assessed according to the clinical presentation; blood pressure and number of agents in those with renovascular hypertension, delta glomerular filtration rate in those with ischaemic nephropathy and heart failure re-admissions in those with heart failure syndromes.ResultsDuring this 5-year period, 127 patients with stenosis ≥ 50% were considered by the multidisciplinary team, with 57 undergoing revascularization (17 primarily for severe hypertension, 25 deteriorating kidney function, 6 heart failure syndrome and 9 for very severe anatomical stenosis). Seventy-nine percent of all revascularized patients had a positive outcome specific to their clinical presentation, with 82% of those with severe hypertension improving blood pressure control, 72% with progressive ischaemic nephropathy having attenuated GFR decline, and no further heart failure admissions in those with heart failure. Seventy-eight percent of patients revascularized for high grade stenosis alone had better blood pressure control with 55% also manifesting renal functional benefits.ConclusionsMulti-disciplinary team discussion successfully identified a group of patients more likely to benefit from revascularization based on 3 key factors: clinical presentation, severity of the renal artery lesion and the state of the kidney beyond the stenotic lesion. In this way, a large proportion of patients can clinically improve after revascularization if their outcomes are considered according to the nature of their clinical presentation.Graphical

Renal Artery Reimplantation Versus Bypass in Elective Open Aneurysm Repair

Complex open abdominal aortic aneurysm (AAA) repair often necessitates revascularization of renal arteries by either renal artery reimplantation or bypass. This study aims to evaluate the perioperative and short term outcomes between these two strategies of renal artery revascularization. We performed a retrospective review of patients who underwent open AAA repair from 2004-2020 at our own institution. Patients who underwent elective suprarenal, juxtarenal, or type 4 thoracoabdominal aneurysm repair were identified using current procedural terminology (CPT) codes as well as a retrospectively maintained database of AAA patients. Patients who had symptomatic aneurysm or significant renal artery stenosis prior to AAA repair were excluded. Patient demographics, intraoperative conditions, renal function, bypass patency and perioperative and postoperative outcome at 30 days and 1 year were compared. 143 patients underwent either renal artery reimplantation (n=86) or bypass (n=57) during this time period. The mean age was 69.7 years and 76.2% of the patients were male. Median preoperative creatinine was 1.2 mg/dL for the renal bypass group vs 1.06 mg/dL for reimplantation (P=0.088). Both groups had similar median preoperative glomerular filtration rate (GFR) of >60 mL/min (P=0.13). Bypass and reimplantation groups had similar perioperative complications including acute kidney injury (51.8% vs 49.4% P=0.78), inpatient dialysis (3.6% vs 1.2% P=0.56), myocardial infarction (1.8% vs 2.4% P=0.99), and death (3.5% vs 4.7% P=0.99), respectively. During the 30 day follow-up period, renal artery stenosis was identified in 9.8% of bypasses and 6.7% of reimplantations (P=0.71). 6.1% of patients in the bypass group had renal failure requiring dialysis (both acute and permanent) compared to 1.3% in reimplantation group (P=0.3). For those who had 1 year follow up, the reimplantation group had higher new incidence of renal artery stenosis compared to bypass group (6 vs. 0 p=0.16). Given that there is no significant difference in outcomes between renal artery reimplantation and bypass within 30 days or at 1 year follow-up, both bypass and re-implantation are acceptable means for renal artery revascularization during elective AAA repair.

Consensus on renovascular hypertension: diagnosis and treatment

The clinical significance of renovascular arterial hypertension is determined by it is high prevalence as well as it is negative impact on prognosis. The most common causes of renovascular arterial hypertension are atherosclerotic stenosis of the renal arteries and fibromuscular dysplasia. Renovascular arterial hypertension is characterized by the development of blood pressure resistant to antihypertensive therapy with an unfavorable prognosis of worsening renal function and cardiovascular complications. Currently, the most available screening method in the diagnosis of renovascular arterial hypertension is duplex scanning of the renal arteries. Non-invasive diagnostic methods also include magnetic resonance and multispiral computed tomography with intravenous contrast. Contrast angiography remains “the golden standard” for diagnosing renovascular arterial hypertension and determining the indications for surgical treatment. Together with the use of diagnostic techniques such as measurement of translesion pressure gradient and fractional blood flow reserve, it allows to assess the functional significance of renal artery stenosis. Treatment of renovascular arterial hypertension is a complex process aimed at normalization of blood pressure, improvement of renal function, as well as mortality and cardiovascular risk reduction. To date, the feasibility of endovascular treatment remains an open question. More often the preference is given to conservative treatment. The indications for renal artery revascularization are less obvious, available clinical guidelines and results of large trials are controversial.

Contrast-induced nephropathy after recanalization chronic coronary occlusion in patients with renal artery stenosis and normal creatinine levels

Introduction. Contrast-induced nephropathy (CIN) is a complication that occurs after contrast medium (CM) administration. The existing risk scales for possible CIN include chronic kidney disease and do not take into account stenotic changes in the renal artery with normal serum creatinine levels.The Objective was to study the frequency of CIN in patients with acute and chronic coronary occlusion (CCO) after endovascular recanalization in the presence of hemodynamically significant renal artery damage with initially normal creatinine levels.Methods and Materials. The study included 38 patients with acute coronary syndrome (control group) and 67 patients with CCO and hemodynamically significant renal artery stenosis (main group). Stenting of one of the renal arteries was performed in 25 patients out of 67 patients before planned coronary revascularization.Results. The incidences of CIN were significantly higher than the calculated one in patients with CCO and renal artery stenosis. In the group of patients with pre-stenting of the renal arteries, there was a decrease in cases of CIN.Conclusions. Renal artery stenosis with normal creatinine levels is an additional risk factor for CIN.

THE RISKS AND BENEFITS OF RENAL ARTERY STENTING IN FIBROMUSCULAR DYSPLASIA. LESSONS FROM ARCADIA-POL STUDY

Objective: Percutaneous transluminal angioplasty (PTA) is the recommended revascularization strategy in patients with renal artery stenosis (RAS) caused by fibromuscular dysplasia (FMD), limiting stenting to complications management. However this recommendation is based on cases reports and small series. The main aim of the study was to retrospectively analyze immediate and long-term results of renal stenting and PTA in FMD patients. The second aim was to evaluate the results of stenting as support of renal artery aneurysm (RAA) closure. Design and method: The study group consisted of 58 patients percutaneously treated due to significant RAS (70 arteries) and 9 patients (10 RAAs) with a history of stent implantation before aneurysm embolization, derived from 343 ARCADIA-POL registry patients. PTA was performed as initial treatment in 61 arteries (PTA-group), whereas primary stenting was done in 9 arteries (STENT-group). Stent-related complications(SRC) were defined as: in-stent restenosis (&gt;50%) or occlusion (ISR/O); stent fracture; stent underexpansion (SU) or migration. Results: In PTA-group, the first restenosis rate was 50.8%. Subsequently, 22 arteries underwent a second procedure: re-PTA(12 arteries) or stent implantation(10 arteries) . The incidence of recurrent restenosis after re-PTA was 41.7%. In the 10 arteries initially treated with PTA that underwent stenting for restenosis, complications occurred in 7 of them (70%), including 2 SUs and 5 ISR/Os . In STENT-group, SU occurred in one case (11.1%) and in-stent restenosis in 33.3% (3 of 9 stents). In combined analysis, SRC occurred following 11/19 stenting procedures (57.9%) including 3 periprocedural (SUs) and 8 late complications (ISR/Os). Finally, despite several subsequent revascularization attempts, 4 of 19 (21%) stented arteries were totally occluded and one remained significantly stenosed at follow-up imaging (Figure). In contrast to FMD-RAS procedures, there was only one intraprocedural complication (partial stent migration) and no late SRC in RAA patients. Conclusions: Renal artery stenting in FMD provides modest benefit in terms of restenosis prevention but poses high risk of immediate and late complications, including stent occlusion. Our study supports recommendations limiting stenting to the management of complications. In contrast, renal artery stenting in FMD RAA closure is associated with favorable long-term outcomes.

Defining Hemodynamic Significance of Renal Artery Stenosis: Insights From a Porcine Model of Graded Renal Artery Stenosis

To investigate the renal pressure-flow relationship and its relation to renin release, because the renal perfusion pressure below which renal flow starts to decline and renin secretion isupregulatedis unclear. A porcine model of graded unilateral renal artery stenosis was created. The severity of the stenosis was expressed as the ratio between distal renal pressure (Pd) and aortic pressure (Pa). Pd and renal flow velocity were continuously measured using a combined pressure-flow wire (Combowire®). Hemodynamic measurements and blood sampling for renin, angiotensin and aldosterone were performed in baseline conditions and during progressive balloon inflation in the renal artery leading to Pd decrease per 5% increment. Resistive index (RI)was computed as (1-(End Diastolic V/Peak Systolic V))*100. For a 5% decrease in renal perfusion pressure (95% of aortic pressure or 5% decrease compared to Pa), peak systolic velocity started to decrease. A significant decrease in average peak flow velocitywas observed when distal renal perfusion pressure decreased by 25% and was associated with activation of ipsilateral renin secretion. The RI decreased already for minimal changes in Pd/Pa ratio. In an animal model of unilateral graded renal artery stenosis, a 25% decrease in perfusion pressure results in a significant decrease in distal renal flow, causing upregulation of renin secretion.

PS-BPR02-9: RECURRENCE OF RENAL ARTERY STENOSIS BY PONATINIB, A MULTI-TARGETED TYROSINE-KINASE INHIBITOR

Introduction: Cardiovascular disease and drug induced hypertension have been reported with tyrosine-kinase inhibitor including ponatinib treatment in chronic myeloid leukemia (CML) and Philadelphia chromosome-positive acute lymphoblastic leukemia (Ph+ALL). We report bilateral renal artery stenosis (RAS) in a patient who had received ponatinib for relapsing Ph+ALL after 2nd allogeneic stem cell transplantation. Case: A patient was a 40-year-old woman with no history of cardiovascular disease and hypertension. She developed myocardial damage that appeared to be ponatinib -induced, and catheterization of the heart revealed multiple coronary artery lesions and started optical medical therapy. 16 months after ponatinib treatment, she was referred to the nephrology department for evaluation of hypertension and increase in serum creatinine from 1.47 to 2.02 mg/dL. Renal ultrasonography and MRI revealed significant stenosis of the right renal artery, and angiography and stenting were performed. 5 months after the stent treatment, progression of renal dysfunction due to exacerbated RAS was observed. Intravascular ultrasonography revealed diffuse intimal thickening occurred in-stent restenosis, and balloon dilation was performed. She required balloon dilatation a total of three times even after the discontinuation of ponatinib treatment. The patient was thought to have systemic vascular endothelial damage caused by ponatinib. Discussion: It should be considered when hypertension and renal dysfunction occurs after ponatinib use

Assessment of hemodynamic significance of renal artery stenoses in endovascular treatment of resistant vasorenal arterial hypertension

Objective. To determine the significance of renal artery stenosis according to different methods of assessing the functional significance of stenosis and to evaluate the safety and efficacy of stenting of unilateral renal artery stenosis after 6 months and 1 year according to office BP and ABPM.Materials and methods. The study included 44 patients with resistant arterial hypertension and renal artery stenosis (mean age 69 ± 11 years), while receiving multicomponent antihypertensive therapy, including diuretic. After assessing the degree of RA stenosis according to selective angiography and additional methods of assessing the functional significance of RA stenosis (iFR, Pd/Pa, translesional gradient and FFR) the patients underwent RA stenting. The safety of the procedure was assessed by creatinine and glomerular filtration rate dynamics (MDRD equation). The effectiveness of the procedure was study according to office blood pressure (BP) and ambulatory BP monitoring (ABPM).Results. According to the results of angiography, the patients were divided into two groups: group A – patients with subtotal PA stenosis (&gt; 90%) and group B – patients with moderate stenosis (60-90%), who underwent additional assessment of the functional significance of stenosis. The immediate angiographic result in both groups was optimal (the degree of residual stenosis was less than 5%). In group B, after stent implantation in the PA, there was a decrease of the translesional gradient by 38 ± 10 mm Hg (p &lt; 0,0001), FFR &gt; 0,8(p &lt; 0.0001). iFR &gt; 0.89, Pd/Pa&gt;0.9 (p = 0,093). In both groups, there was a significantly significant reduction in arterial blood pressure at distant times, according to clinical BP measurement and ABPM.Conclusion. The measurement of such parameters as translesional gradient and fractional reserve is the most reliable in assessing the hemodynamic significance of PA stenosis in comparison with iFR and Pd/Pa measurements in patients with moderate PA stenosis. PA stenting in patients with uncontrolled resistant AH and severe renal artery lesions, as well as moderate stenosis confirmed by additional methods of stenosis functional significance assessment is reasonable to consider in order to enhance the antihypertensive effect.

Ultra-Low-Dose Contrast Using Transluminal Renal Angioplasty: The ULTRA Study.

Although severe atherosclerotic renal artery stenosis (ARAS) is a predictor of future cardiovascular events, large trials have not shown the benefits of percutaneous transluminal renal angioplasty (PTRA). This study aimed to validate the safety and efficacy of PTRA using low-concentration digital subtraction angiography (LC-DSA) in patients with severe ARAS and advanced chronic kidney disease (CKD). This prospective study was conducted between August 2018 and October 2021. Eighteen patients with 20 lesions, CKD stage 3b or worse, and significant renal artery stenosis were included and underwent PTRA using ultra-low-dose contrast medium. The primary endpoint was a change in renal function based on serum creatinine (sCr) level. The mean sCr level significantly improved from 3.34 ± 1.8mg/dL pre-PTRA to 2.48 ± 1.19mg/dL at 1 month post-PTRA (P = .02). The mean amount of contrast used was 8.3 ± 3.9mL per vessel. More severe stenosis and rapid deterioration of renal function before treatment were associated with improved kidney function. No cardiovascular or renal complications such as stroke or contrast-induced nephropathy were observed during the 30-day period. PTRA using an ultra-low-dose contrast medium is safe and provides acceptable results.

Transplant Renal Artery Stenosis: Current Concepts.

Transplant renal artery stenosis is an increasingly recognized vascular complication after renal transplant. It can result in posttransplant hypertension and graft dysfunction and eventually in graft loss. Timely diagnosis and appropriate intervention for clinically significant transplant renal artery stenosis can potentially halt or reverse these adverse effects, leading to better outcomes. Duplex ultrasonography is the imaging modality of choice to screen suspected cases. Some patients with transplant renal artery stenosis will require invasive treatment with endovascular intervention or surgery, whereas others can be safely treated with blood pressure control and follow-up. In this review, we aimed to discuss the epidemiology, clinical presentation, pathogenesis, diagnosis, and management of this common posttransplant complication.

Incidence of renal artery stenosis and its hemodynamic significance in patients subjected to angiography for suspected coronary artery disease

Background: Renal artery stenosis (RAS) may occur alone (isolated anatomical RAS) or in combination with hypertension (renovascular or essential hypertension), renal insufficiency (ischemic nephropathy), or both. Renal artery stenting can be performed safely with nearly uniform technical success without exposing them to significant incremental risk. Aims and Objectives: The objectives of the study are as follows: (A) To study the incidence of RAS in suspected coronary artery disease patients. (B) To study the hemodynamic significance of RAS in patients diagnosed having RAS. (C) Should patients undergoing coronary angiography be subjected to routine renal angiography during the procedure? Materials and Methods: We prospectively did renal angiography of consecutive 100 patients, who underwent coronary angiography for their suspected coronary artery disease. Data regarding risk factors were recorded for every patient. Results: Out of 12 patients with RAS, 10 had significant stenosis (&gt;50%) out of which seven patients showed hemodynamically significant RAS on captopril renogram. These were the patients having stenosis of 70% or more on renal angiography. Three patients having RAS 50–70% on renal angiography were not having hemodynamically significant lesion on captopril renograms. Conclusion: Renal angiography should be performed in patients undergoing coronary angiography. Femoral artery should be the preferred access site for coronary angiography to approach renal arteries. The patients with RAS should undergo captopril renography to evaluate the hemodynamic significance of the stenosis.

CARDIOHEMODYNAMIC AND PROGNOSTIC SIGNIFICANCE OF RENAL ARTERY STENTING IN PATIENTS WITH CORONARY ARTERY DISEASE

The aim of the study is to evaluate cardiohemodynamic and prognostic significance of endovascular revascularization of renal arteries (ERRA) in patients with coronary artery disease (CAD).&#x0D; Materials and Methods. The authors examined 106 patients (84 men, 22 women; mean age 53±15). All the patients underwent both coronary angiography and renal artery angiography to verify chronic CAD. The authors analyzed the incidence and severity of arterial hypertension, the results of coronary and renal artery angiography, the outcomes of endovascular management of renal artery stenosis (RAS), and all-cause mortality rates. The follow-up period lasted for 10 years.&#x0D; Results. CAD was detected in 61 patients (58 %). Synchronous coronary and renal artery damage was detected in 12 patients (19.7 %), including hemodynamically significant renal artery stenosis (9 patients (14.8 %)). Eight patients underwent renal artery stenting. Arterial hypertension was observed in 58 of 61 patients (95.1 %) with verified CAD, including all the patients with synchronous coronary and renal artery damage. Seventeen patient (16 %) died during the monitoring period. During a 10-year period, 3 people (25 %) died from all causes in the group of RAS patients, while 14 people (14.8 %) died in the group of patients without RAS (χ=1.22; р=0.37). Twelve months after renal artery stenting, there was a decrease in systolic blood pressure load, a decrease in the number of unfavorable blood pressure profiles, and a decrease in end-diastolic dimension.&#x0D; Conclusions. In the medium term, ERRA is associated with a decrease in hypertensive load indices and systolic BP variability, an improvement of circadian blood pressure profiles, and a decrease in left ventricle end-diastolic and left atrium dimensions. Renal artery stenosis and ERRA did not significantly affect mortality over a 10-year follow-up.

A 63–year–old female with bilateral renal artery stenosis – highlights on diagnosis and optimal medical treatment

Renal artery stenosis is responsible for approximately 75% of secondary hypertensive cases. A 63-year-old female patient with uncontrolled hypertension and other comorbidities including type 2 diabetes mellitus and knee osteoarthritis presented with drastically raised systolic blood pressure in this case report (220 mmHg). Bilateral abdominal bruits were detected upon of physical examination. Imaging investigation showed significant bilateral atherosclerotic renal artery stenosis. An optimal combination of antihypertensive agents mainly with an angiotensin converting enzyme inhibitor, other than interventional revascularization, was applied and resulted in controlled blood pressure.

Impact of Percutaneous Transluminal Renal Angioplasty on Autonomic Nervous System and Natriuresis in Hypertensive Patients With Renal Artery Stenosis.

BackgroundWe investigated the early postoperative effect of percutaneous transluminal renal angioplasty on ambulatory blood pressure (BP) and the circadian characteristics of natriuresis and autonomic nerve activity.Methods and ResultsA total of 64 patients with hypertension with hemodynamically significant renal artery stenosis (mean age, 60.0±21.0 years; 31.3% fibromuscular dysplasia) who underwent angioplasty were included, and circadian characteristics of natriuresis as well as heart rate variability indices, including 24‐hour BP, low‐frequency and high‐frequency (HF) components, and the percentage of differences between adjacent normal R‐R intervals >50 ms were evaluated using an oscillometric device, TM‐2425, both at baseline and 3 days after angioplasty. In both the fibromuscular dysplasia and atherosclerotic stenosis groups, 24‐hour systolic BP (fibromuscular dysplasia, −19±14; atherosclerotic renal artery stenosis, −11±9 mm Hg), percentage of differences between adjacent normal R‐R intervals >50 ms, HF, brain natriuretic peptide, and nighttime urinary sodium excretion decreased (all P<0.01), and heart rate increased (both P<0.05) after angioplasty. In both groups, revascularization increased the night/day ratios of percentage of differences between adjacent normal R‐R intervals >50 ms (both P<0.01) and HF, and decreased those of low frequency/HF (all P<0.05) and nighttime urinary sodium excretion (fibromuscular dysplasia, 1.17±0.15 to 0.78±0.09; atherosclerotic renal artery stenosis, 1.37±0.10 to 0.99±0.06, both P<0.01). Multiple logistic regression analysis indicated that a 1‐SD increase in baseline low frequency/HF was associated with at least a 15% decrease in 24‐hour systolic BP after angioplasty (odds ratio, 2.30 [95% CI, 1.03–5.67]; P<0.05).ConclusionsSuccessful revascularization results in a significant BP decrease in the early postoperative period. Intrarenal perfusion might be a key modulator of the circadian patterns of autonomic nerve activity and natriuresis, and pretreatment heart rate variability evaluation seems to be important for treatment success.