Restenosis after stenting of atherosclerotic renal artery stenosis: Is there a rationale for the use of drug-eluting stents?

Endovascular treatment of renal artery stenosis in Germany: a retrospective analysis of the DEGIR registry 2018-2021

PURPOSE

 To provide an overview of endovascular treatment of renal artery stenosis (RAS) using the data of the Deutsche Gesellschaft für interventionelle Radiologie (DeGIR) quality management system.

MATERIALS AND METHODS

 A retrospective analysis was performed. Pre-, peri- and postprocedural data, technical success rates, complication rates, and clinical success rates at dismissal were examined.

RESULTS

 Between 2018 and 2021, 2134 angiography examinations of the renal arteries were performed: diagnostic angiography in 70 patients (3 %), balloon angioplasty in 795 (37 %), stent implantation in 1166 (55 %) and miscellaneous procedures in 103 (5 %). The lesion length was less than or equal to 5 mm in 1837 patients (87 %), between 5 and 10 mm in 197 (9 %), and between 10 and 20 mm in 62 (3 %). The degree of stenosis was less than 50 % in 156 patients (7 %), greater than 50 % in 239 (11 %), and greater than 70 % in 1472 (70 %). Occlusion was treated in 235 patients (11 %). Symptoms at discharge resolved in 600 patients (29 %), improved in 1012 (49 %), were unchanged in 77 (4 %), and worsened in 5 (0.2 %). Complications were reported in 51 patients (2.5 %) and the mortality rate was 0.15 %.

CONCLUSION

 A substantial number of patients with RAS and occlusions were treated by radiologists in Germany, with high technical success rates and low complication rates. The indication should be determined carefully as the current European guidelines for the treatment of RAS suggest that only carefully selected groups of patients will benefit from recanalizing treatment.

KEY POINTS

  · Carefully selected patient groups may benefit from endovascular treatment of renal artery stenosis.. · Analysis of the DEGIR quality management database shows that treatment of renal artery stenosis was performed by radiologists in Germany with high technical success rates and low complication rates.. · Recanalization even led to symptom improvement in a large proportion of patients with occlusions..

Restenosis Rates After Drug-Eluting Stent Treatment for Stenotic Small-Diameter Renal Arteries

PURPOSE

To determine primary rates in small-diameter renal arteries, including complex bifurcation lesions, treated with drug-eluting stents (DES) in patients with atherosclerotic renal artery stenosis.

MATERIALS AND METHODS

This is a retrospective single-institution study. A total of 37 patients with 39 stented renal arteries were included. Patient and procedural data were obtained from the electronic medical record. Survival free from restenosis was estimated using the Kaplan-Meier method with patients stratified into two groups based on renal artery diameters (≤ 3.5 mm or > 3.5 mm). Univariate Cox proportional models were used to estimate hazard ratios associated with clinical and angiographic variables.

RESULTS

Average renal artery diameter at time of treatment was 3.4 mm ± 0.4 mm. The median survival free from restenosis was 992 days, with 11 out of 37 (29.7%) developing an in-stent restenosis. Renal arteries < 3.5 mm in diameter had similar patency rates as renal arteries > 3.5 mm (P = 0.33). The 1-, 2-, and 5-year patency rates were 71%, 63%, and 38%, respectively. History of stroke was the only comorbidity to portend a significantly greater rate of restenosis (hazard ratio 3.77; 95%CI, 1.05-13.6; P = 0.04). Medications did not statistically alter the risk of restenosis.

CONCLUSION

Revascularization of renal arteries with DES achieved similar primary patency rates irrespective of renal artery diameter. Stent configuration was not associated with time to renal replacement therapy or all-cause mortality.

LEVEL OF EVIDENCE

Level 3, Cohort Study.

Drug-eluting stents versus bare metal stents for the prevention of restenosis in patients with renovascular disease

AIMS

The aim of this study was to assess the impact of drug-eluting stents (DES) compared to bare metal stents (BMS) for the endovascular treatment of atherosclerotic renal artery stenosis (ARAS).

METHODS AND RESULTS

We retrospectively evaluated all of our endovascular BMS and DES implantations performed in de novo ARAS between 2000 and 2014 at our institution. The occurrence of in-stent restenosis (ISR) detected by ultrasound or angiography, kidney function, blood pressure (BP), and the number of antihypertensive drugs were analysed as endpoints. Overall, 338 renal arteries were treated in 298 patients. BMS were implanted in 163 (48%), and DES in 175 lesions (52%). Of the 175 lesions treated with DES, 55 (31%) were treated with a BMS-in-DES hybrid technique. For reasons of comparability, only lesions treated with balloon sizes of 4-6.5 mm were included in the final analysis. After 12 months, the rate of ISR >50% was 18.6% in the BMS group and 7.2% in the DES group (p=0.031). None of the BMS-in-DES-treated (hybrid) lesions developed ISR (hybrid technique vs. BMS only p=0.008, hybrid technique vs. DES only p=0.034). Systolic BP and number of antihypertensive drugs remained unchanged in the BMS group but declined in the DES group (p=0.02). Renal function significantly deteriorated in the BMS group (p=0.03) but did not change significantly in the DES group (p=0.188).

CONCLUSIONS

DES were superior to BMS in preventing ISR. Overall, the BMS-in-DES-technique (hybrid) achieved the lowest risk for ISR.

Renal artery stenosis: prevalence of, risk factors for, and management of in-stent stenosis

Atherosclerotic renal artery stenosis is common and is associated with hypertension and chronic kidney disease. More frequent use of percutaneous renal artery stent placement for the treatment of renal artery stenosis during the past 2 decades has increased the number of patients with implanted stents. In-stent stenosis is a serious problem, occurring more frequently than earlier reports suggest and potentially resulting in late complications. Currently, there are no guidelines covering the approach to restenosis after renal artery stent placement. This article reviews data on the prevalence of and risk factors for the development of in-stent stenosis and the clinical manifestations, evaluation, and treatment of in-stent stenosis and suggests a strategy for the management of patients after percutaneous renal artery stent placement.

Use of drug-eluting stent with provisional T-stenting technique in the treatment of renal artery bifurcation stenosis; long-term angiographic follow-up

Atherosclerotic renal artery stenosis (RAS) usually involves the ostium and the proximal one-third of the renal artery main branch. Percutaneous renal artery angioplasty with stent placement is a well recognized treatment for atherosclerotic RAS. Occasionally, atherosclerotic RAS involves renal artery bifurcations. However, stent implantation in atherosclerotic RAS involving bifurcation is not only troublesome, but also challenging because of side branch occlusion and in-stent restenosis (ISR). In the present report, we describe the use of drug-eluting stents (DES) with provisional T-stenting technique for the treatment of renal artery bifurcation lesion. Follow-up angiogram showed no significant ISR 18 months after the procedure. In the treatment of renal bifurcation lesions, a two-stent strategy using DES could be a viable option in selected patients.

Renovascular hypertension and ischemic nephropathy

Renovascular disease remains among the most prevalent and important causes of secondary hypertension and renal dysfunction. Many lesions reduce perfusion pressure including fibromuscular diseases and renal infarction, but most are caused by atherosclerotic disease. Epidemiologic studies establish a strong association between atherosclerotic renal-artery stenosis (ARAS) and cardiovascular risk. Hypertension develops in patients with renovascular disease from a complex set of pressor signals, including activation of the renin-angiotensin system (RAS), recruitment of oxidative stress pathways, and sympathoadrenergic activation. Although the kidney maintains function over a broad range of autoregulation, sustained reduction in renal perfusion leads to disturbed microvascular function, vascular rarefaction, and ultimately development of interstitial fibrosis. Advances in antihypertensive drug therapy and intensive risk factor management including smoking cessation and statin therapy can provide excellent blood pressure control for many individuals. Despite extensive observational experience with renal revascularization in patients with renovascular hypertension, recent prospective randomized trials fail to establish compelling benefits either with endovascular stents or with surgery when added to effective medical therapy. These trials are limited and exclude many patients most likely to benefit from revascularization. Meaningful recovery of kidney function after revascularization is limited once fibrosis is established. Recent experimental studies indicate that mechanisms allowing repair and regeneration of parenchymal kidney tissue may lead to improved outcomes in the future. Until additional staging tools become available, clinicians will be forced to individualize therapy carefully to optimize the potential benefits regarding both blood pressure and renal function for such patients.

Sirolimus-eluting stent placement for refractory renal artery in-stent restenosis: sustained patency and clinical benefit at 24 months

Abstract

Renal artery stenosis may cause or exacerbate hypertension and renal failure. Percutaneous transluminal renal artery stent placement, increasingly the first-line therapy for ostial atherosclerotic renal artery stenosis, can be complicated by in-stent restenosis weeks to months after the procedure. There is currently no consensus for the treatment of in-stent restenosis. Sirolimus-eluting stents have been shown to be effective to treat in-stent restenosis in the coronary circulation. We report a case of sustained 24-month patency after repair of recurrent renal artery in-stent restenosis with use of a sirolimus-eluting stent.

Treatment of renal artery in-stent restenosis with sirolimus-eluting stents

The objective of this study was to analyze the use of sirolimus-eluting stent (SES) placement for the treatment of renal artery in-stent restenosis (RA-ISR). The optimal treatment of RA-ISR has not been fully elucidated to date. We retrospectively analyzed consecutive patients from our institution who underwent treatment of RA-ISR with a SES from May 2004 to June 2006. Using duplex ultrasound, RA-ISR (> 60% diameter) was determined by peak systolic velocity (PSV) > 300 cm/s and renal aortic ratio (RAR) > 4.0. Renal function (creatinine) and blood pressure were measured at baseline and follow-up. SESs were implanted in 16 patients (22 renal arteries) during the study period. The study cohort was predominantly female (75%) with a mean age of 68 +/- 12 years. RA-ISR was treated with SESs with a mean diameter of 3.5 mm and mean length of 17.9 +/- 3.8 mm. The mean post-dilation balloon diameter was 4.8 +/- 0.6. The baseline renal artery PSV was 445 +/- 131 cm/s with a mean RAR of 5.0 +/- 1.6. Follow-up information was available in 21 renal arteries. During a median follow-up of 12 months (range: 9-15 months), 15 renal arteries (71.4%) developed recurrence of ISR by ultrasonographic criteria. Univariate analysis revealed that female sex was an independent predictor of recurrence of ISR after SES implantation (p < 0.05). In conclusion, placement of a SES for the treatment of ISR in renal arteries is associated with high initial technical success but significant restenosis on duplex ultrasonography at follow-up.

Atherosclerotic renal artery stenosis: current therapy and future developments

Atherosclerotic renal artery stenosis affects between 2 and 4 million people in the United States alone and likely has a higher prevalence than previously thought. Renal artery stenosis has been increasingly recognized in recent years, especially in patients with cardiovascular disease. It has been associated with hypertension, renal dysfunction, and sudden onset of pulmonary edema. Patients with symptomatic and hemodynamically significant renal artery stenosis are candidates for revascularization. Revascularization is most often accomplished by renal artery stenting, which has high success rates in terms of patency and low complication rates. An important element in managing patients with renal artery stenosis is selecting those patients who are most likely going to benefit from revascularization. This review article focuses on the clinical diagnosis, current treatment options, and future directions regarding treatment of patients with renal artery stenosis.

Drug-eluting stents in the management of peripheral arterial disease

Since major meta-analyses of randomized controlled trials in interventional cardiology showed the potential of drug-eluting stents in decreasing restenosis and reintervention rates after coronary artery stenting, one of the next steps in the treatment of arterial occlusive disease is the transfer of the active coating technology towards peripheral arterial interventions. In this manuscript, we aim to provide a literature overview on available peripheral (lower limb, renal, and supra-aortic) drug-eluting stent applications, debate the cost implications, and give recommendations for future treatment strategies.

The role of percutaneous revascularization for renal artery stenosis

Renal artery stenosis (RAS) is usually caused by atherosclerosis or fibromuscular dysplasia. RAS leads to activation of the renin-angiotensin-aldosterone system and may result in hypertension, ischemic nephropathy, left ventricular hypertrophy and congestive heart failure. Management options include medical therapy and revascularization procedures. Recent studies have shown angiotensin receptor blockers (ARB) and angiotensin converting enzyme inhibitors (ACE-I) to be highly effective in treating the hypertension associated with RAS and in reducing cardiovascular events; however, they do not correct the underlying RAS and loss of renal mass may continue. Renal artery angioplasty was first performed by Gruntzig in 1978. The routine use of stents has increased technical success rates compared with angioplasty, and surgery is now only rarely performed. Although numerous case series claimed benefit in terms of blood pressure control, no adequately powered randomized, controlled, prospective study of renal artery interventions has reported their effect on cardiovascular morbidity or mortality. The CORAL trial, an ongoing study of renal artery stent placement and optimal medical therapy (OMT) funded by the National Institutes of Health, is the first study to attempt to do so. Until the CORAL trial results are in, physicians will continue to be faced with difficult choices when determining the optimal management for RAS patients and deciding which, if any, patients should be offered revascularization.

[Atherosclerotic renal artery disease management update]

In the case of atherosclerotic renal artery disease, the best conclusive results lie principally not in the degree of the stenosis but rather in the degree the renal parenchymal disease beyond the stenosis itself. These determining factors involve the controlling of the patients blood pressure, the improvement in the renal function and the beneficial results to the cardiovascular system. Besides the indispensable medical treatment, a revascularisation by angioplasty may be indicated. This procedure with or without vascular stent often allows satisfactory angiographic results. A treatment by surgical revascularisation is only recommended in the case of extensive atherosclerotic lesions of the aorta, complex lesions of the latter or an abdominal aortic aneurism. Although the frequency of restenosis of angioplasty with stent remains extremely low, the risk of cholesterol emboli due to the diffuse atherosclerotic lesions of the abdominal aorta, must be considered at the time of each aortic catheterization. The therapeutic approach of atherosclerotic renal artery disease must be dictated by the whole cardiovascular risk factors and by the threat of target organs. The control of the blood pressure and the maintenance of the renal function must be integrated in the decisional algorithm as well as the possible risks in carrying out an eventual revascularisation procedure. Finally, the renal angioplasty should in numerous situations be integrated in the overall assumption of responsibility of the atherosclerotic vascular diseases, and should be part of the medical treatment. Several questions still do exist; at what moment an atherosclerotic renal artery stenosis should and e considered critical, and which procedure should be considered for which patient? The purpose of this review is to propose a decisional tool for individualized treatments in the light of results from randomized and controlled studies.

Renal artery stenosis

Fibromuscular dysplasia (FMD) and aortoarteritis are the most frequent causes of secondary hypertension induced by renal artery stenosis (RAS). Revascularization of this disease entity usually cures arterial hypertension. Demographic evolution leads to an increasing incidence of atherosclerotic RAS, one of the major causes of end-stage renal failure. Furthermore, atherosclerotic RAS leads to deterioration of primary hypertension, progression of atherosclerosis manifestation such as occlusive and aneurysmatic peripheral artery disease, and chronic or acute organ damage such as left ventricular hypertrophy and recurrent flash pulmonary edema. Despite the lack of sufficiently powered randomized controlled trials, each hemodynamically relevant RAS (eg, > or = 70%) should be considered for stent angioplasty in patients without end-stage ischemic nephropathy or limited life expectancy due to concomitant disease (eg, cancer). Drug-eluting stents will probably reduce the overall low in-stent restenosis rate of 10% to 20%. Interventions in patients with dialysis-dependent end-stage nephropathy are left to appropriate clinical study protocols.

Sirolimus-eluting biodegradable poly-L-lactide stent for peripheral vascular application: a preliminary study in porcine carotid arteries

BACKGROUND

To assess technical feasibility and biocompatibility of a new Sirolimus (SIR)-eluting biodegradable poly-L-lactide (PLLA) stent for peripheral vascular application.

MATERIAL AND METHODS

In 15 pigs, both common carotid arteries (CCA) were surgically exposed and clamped in the proximal segment. After transverse incision, 12 316L stents, 12 unloaded and 6 SIR-loaded PLLA stents mounted on 6.0 x 40-mm balloon catheters were randomly implanted into the CCA and inflated to 8 bar. Angiographic equipment was not available. Stented CCA were explanted after 1 week (6 pigs; 316L versus PLLA) and 6 weeks (9 pigs; 316L versus PLLA versus SIR-PLLA), and processed for quantitative histomorphometry and estimation of vascular inflammation and injury scores.

RESULTS

No animals were lost during follow-up. All stents were patent on histological analysis without any signs of excessive recoiling or collapse. Unloaded PLLA stents showed decreased residual lumen area and increased neointimal area after 1 week (13.16 +/- 0.34, 1.94 +/- 0.26) and 6 weeks (11.57 +/- 0.30, 2.85 +/- 0.24) as compared with 316L stents (15.26 +/- 0.13, 1.27 +/- 0.41 and 13.99 +/- 0.51, 1.54 +/- 0.59). SIR-eluting stents demonstrated comparable neointimal area (1.75 +/- 0.38) and 50% lower intimal thickness as compared with 316L stents after 6 weeks, but a slightly decreased residual lumen (13.06 +/- 0.32) in the consequence of differences in strut thickness (PLLA, 270 microm; 316L, 155 microm). The vascular inflammation score against PLLA-stents could be reduced by Sirolimus. The vascular injury scores were low and similar in all groups.

CONCLUSIONS

PLLA stents showed sufficient mechanical stability after porcine CCA stenting. By incorporation of Sirolimus, a significant reduction of the inflammatory and neointimal response to the PLLA stent was seen without systemic toxicity or thrombotic complications. These findings need to be assessed with longer follow-up to confirm maintenance of efficacy. The greater strut height of PLLA stents is a major limitation and requires modification.

Treatment of instent restenosis following stent-supported renal artery angioplasty

OBJECTIVES

We prospectively studied the long-term outcome of endovascular treatment of instent renal artery stenosis (IRAS).

BACKGROUND

Restenosis is a considerable drawback of stent-supported angioplasty of renal artery stenosis especially in small vessel diameters. The appropriate treatment strategy is not yet defined.

PATIENTS AND METHODS

During a 10-year period 56 consecutive patients (65 lesions) with their first IRAS were included in a prospective follow-up program (mean follow-up 53 +/- 25 months, range 6-102). Primary endpoint of the study was the reoccurence of IRAS (>or= 70%) after primarily successful treatment of the first IRAS determined by duplex ultrasound.

RESULTS

Primary success rate was 100%, no major complication occurred. Nineteen lesions were treated with plain balloon angioplasty (group 1, 30%), 42 lesions with stent-in-stent placement (group 2, 65%) using various bare metal balloon expandable stents, and 4 lesions with drug-eluting stent angioplasty (group 3, 6%). During follow-up, overall 21 lesions (32%) developed reoccurence of IRAS: n = 7/19 in group 1 (37%), n = 14/42 in group 2 (33%), and n = 0/4 in group 3 (0%; P = 0.573). Reoccurence of IRAS was more likely to occur in smaller vessel diameters than in larger ones [3-4mm: 4/7 (57%); 5 mm: 11/26 (42%); 6 mm: 5/25 (20%); 7 mm: 1/7 (14%), P = 0.088]. Multivariable analysis found bilateral IRAS and IRAS of both renal arteries of the same side in case of multiple ipsilateral renal arteries as independent predictors for reoccurence of IRAS.

CONCLUSION

Treatment of IRAS is feasible and safe. The data demonstrate a nonsignificant trend towards lower restenosis with restenting of IRAS versus balloon angioplasty of IRAS. Individual factors influence the likelihood of reoccurence of IRAS.