Update on intervention versus medical therapy for atherosclerotic renal artery stenosis

Focus on the Most Common Paucisymptomatic Vasculopathic Population, from Diagnosis to Secondary Prevention of Complications

Middle-aged adults can start to be affected by some arterial diseases (ADs), such as abdominal aortic or popliteal artery aneurysms, lower extremity arterial disease, internal carotid, or renal artery or subclavian artery stenosis. These vasculopathies are often asymptomatic or paucisymptomatic before manifesting themselves with dramatic complications. Therefore, early detection of ADs is fundamental to reduce the risk of major adverse cardiovascular and limb events. Furthermore, ADs carry a high correlation with silent coronary artery disease (CAD). This study focuses on the most common ADs, in the attempt to summarize some key points which should selectively drive screening. Since the human and economic possibilities to instrumentally screen wide populations is not evident, deep knowledge of semeiotics and careful anamnesis must play a central role in our daily activity as physicians. The presence of some risk factors for atherosclerosis, or an already known history of CAD, can raise the clinical suspicion of ADs after a careful clinical history and a deep physical examination. The clinical suspicion must then be confirmed by a first-level ultrasound investigation and, if so, adequate treatments can be adopted to prevent dreadful complications.

Renovascular Disease and Mesenteric Vascular Disease

Renal artery stenosis is caused by atherosclerosis and fibromuscular dysplasia and is associated with ischemic nephropathy, renovascular hypertension, and accelerated cardiovascular disease. Routine screening for renal artery stenosis is not recommended but is reasonable in patients who have rapid onset of hypertension, resistant hypertension, progressive renal insufficiency, recurrent pulmonary edema, or repeat admissions for heart failure. Acute mesenteric ischemia is caused by arterial embolism or thrombosis, mesenteric venous thrombosis, or nonocclusive mesenteric ischemia, whereas chronic mesenteric ischemia is most often caused by arterial obstruction. This article reviews the epidemiology, pathophysiology, diagnosis, and management of these two conditions.

Endovascular Treatment of Transplant Renal Artery Stenosis: A Systematic Review and Meta-analysis

OBJECTIVE

Endovascular treatment through either percutaneous transluminal angioplasty (PTA) alone or stenting has been previously used as a treatment for transplant renal artery stenosis (TRAS). This review aimed to investigate the results of endovascular treatment for renal artery stenosis in transplanted kidneys as compared with the outcomes of interventions, medical management, and graft survival in non-TRAS patients.

METHODS

A systematic review of PubMed, Google Scholar, Cochrane, and Scopus was conducted in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines in which studies that reported outcomes of the treatment of TRAS via the endoluminal approach were identified, and their results were meta-analyzed.

RESULTS

Fifty-four studies with a total of 1522 patients were included. A significant reduction of serum creatinine level was found, favoring the stenting group, with a mean difference of 0.68 mg/dL (95% confidence interval (CI), 0.17-1.19; Z=2.60, p=0.0009). Comparison of pre- and post-intervention values of any intervention revealed a significant decrease in overall serum creatinine level (0.65 mg/dL; 95% CI, 0.40-0.90; Z=5.09, p=0.00001), overall blood pressure, with a mean difference of 11.12 mmHg (95% CI, 7.29-14.95; Z=5.59, p=0.00001), mean difference in the use of medications (0.77; 95% CI, 0.29-1.24; p=0.002), and peak systolic velocity (190.05; 95% CI, 128.41-251.69; p<0.00001). The comparison of serum creatinine level between endovascular interventions and best medical therapy favored endovascular intervention, with a mean difference of 0.23 mg/dL (95% CI, 0.14-0.32; Z=5.07, p<0.00001). Graft survival was similar between the treated patients and those without TRAS (hazard ratio, 0.98; 95% CI, 0.75-1.28; p=0.091). The overall pooled success rate was 89%, and the overall complication rate was 10.4%, with the most prevalent complication being arterial dissection.

CONCLUSION

The endovascular treatment of TRAS improves graft preservation and renal function and hemodynamic parameters. PTA + stenting appears to be a more effective option to PTA alone in the stabilization of renal function, with additional benefits from decreased restenosis rates. Further high-quality studies could expand on these findings.

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.

<Learning objective: Because several randomized studies have reported negative results for renal artery stenting (RAS), an individual-based approach is required for the treatment of atherosclerotic renal artery stenosis (ARAS). To determine whether RAS could be effective in patients with ARAS, it is important to assess patient-specific characteristics such as progression of renal failure (e.g. acute worsening), presence of bilateral ARAS, or the existence of a solitary functional kidney, as well as parameters of related examinations such as the renal arterial resistive index.>

Improvement in Hypertension Management with Pharmacological and Non- Pharmacological Approaches: Current Perspectives

PURPOSE

Improving hypertension management is still one of the biggest challenges in public health worldwide. Existing guidelines do not reach a consensus on the optimal Blood Pressure (BP) target. Therefore, how to effectively manage hypertension based on individual characteristics of patients, combined with the pharmacological and non-pharmacological approach, has become a problem to be urgently considered.

METHODS

Reports published in PubMed that covered Pharmacological and Non-Pharmacological Approaches in subjects taking hypertension management were reviewed by the group independently and collectively. Practical recommendations for hypertension management were established by the panel.

RESULTS

Pharmacological mechanism, action characteristics, and main adverse reactions varied across different pharmacological agents, and patients with hypertension often require a combination of antihypertensive medications to achieve the target BP range. Non-pharmacological treatment provides an additional effective method for improving therapy adherence and long-term BP control, thus reducing the risk of cardiovascular diseases, and slowing down the progression of the disease.

CONCLUSION

This review summarizes the available literature on the most convincing guideline principles, pharmacological treatment, biotechnology interference, interventional surgical treatment, managing hypertension with technical means of big data, Artificial Intelligence and Behavioral Intervention, as well as providing future directions, for facilitating Current and Developing knowledge into clinical implementation.

Efficiency of Percutaneous Stent Angioplasty in Renal Artery Stenosis - 15 Years of Experience at a Single Center

PURPOSE

 To determine the therapeutic efficiency of percutaneous revascularization in renal artery stenosis (RAS), as well as the role of comprehensive factors such as patient selection and degree of artery stenosis, on clinical outcome.

METHODS AND MATERIALS

 101 patients with hemodynamically relevant RAS underwent percutaneous angioplasty (PTA). 65.7 % were male (mean age: 64 years; range: 18-84). The clinical data was retrospectively analyzed. The serum creatinine (Cr), glomerular filtration rate (GFR), and blood pressure (BP) levels pre- and postprocedural, between 6 months and 1 year, were retrospectively collected and statistically analyzed.

RESULTS

 Follow-up data was available in 34 (33.7 %) and 28 patients (27.7 %) for Cr and MAP, respectively. A significant drop in mean arterial pressure (MAP) was observed on follow-up (mean -5.27 mmHg). Higher baseline Cr and MAP values showed a more pronounced drop in the follow-up (Cr: p 0.002; difference to baseline -0.25 mg/dL, 95 %CI:-0.36, -0.07 and BP p < 0.001; diff. to baseline -0.72 mmHg; 95 %CI: -1.4, -0.40). There was no association between comorbidities, gender, and degree of stenosis with renal and BP outcome. No significant improvement in renal function was observed on follow-up (mean Cr drop: -0.015 mg/dL). The age group 51-60 years showed a significant improvement in BP (p 0.030; diff. to baseline -19.2 mmHg; 95 %CI: -34, -4.3). There was a slight reduction in antihypertensive medication following angioplasty (0.2 fewer). Minor complications were recorded in five procedures (4.9 %).

CONCLUSION

 Percutaneous renal artery revascularization in the presence of atherosclerotic RAS is a safe procedure associated with a significant drop in post-procedural BP. No significant improvement in renal function was observed. Further prospective studies focused on patient selection are necessary.

KEY POINTS

  · Percutaneous stent angioplasty in renal artery stenosis is associated with a significant improvement in post-procedural blood pressure control.. · There is no improvement in renal function after percutaneous stent angioplasty for renal artery stenosis (RAS).. · Percutaneous stent angioplasty is a safe procedure..

CITATION FORMAT

· Guerreiro H, Avanesov M, Dinnies S et al. Efficiency of Percutaneous Stent Angioplasty in Renal Artery Stenosis - 15 Years of Experience at a Single Center. Fortschr Röntgenstr 2021; 193: 298 - 304.

Results of renal artery revascularization in the post-ASTRAL era with 4 years mean follow-up

Purpose: To investigate contemporary results of percutaneous transluminal renal angioplasty (PTRA).Materials and Methods: A multicentre retrospective study analysing all patients treated with PTRA for primary symptomatic renal artery stenosis (RAS) between 2010 and 2013 at four tertiary centres. Procedures during the preceding four years were counted to evaluate for change in PTRA frequency.Results: The number of PTRA procedures decreased by approximately 50% from 2006 to 2013. Patients treated in the post-ASTRAL period (n = 224) had a significant reduction in mean systolic pressure (168 to 146 mmHg, p < 0.01), diastolic pressure (84 to 76 mmHg, p < 0.01), number of anti-hypertensive drugs (3.54 to 3.05, p < 0.01), and anti-hypertensive treatment index (21.75 to 16.92, p < 0.01) compared to before PTRA. These improvements were maintained at one year and at the last clinical evaluation after a mean follow-up of 4.31 years. Renal function increased transiently without sustained improvement, or deterioration, during later follow-up. Thirteen patients (5.8%) eventually required dialysis, nine of these had eGFR <20 ml/min/1.73 m² before PTRA. There was no difference in outcomes between subgroups differentiated by different indications for PTRA.Conclusion: The frequency of PTRA has decreased, indicating a higher threshold for invasive treatment of RAS in recent years. The reduction in blood pressures, the reduced need for anti-hypertensive medication, and stabilization of renal function over time suggest a clinical benefit for most patients who are now being treated with PTRA.

Understanding and managing atherosclerotic renovascular disease: still a work in progress

Atherosclerotic renovascular disease (ARVD) is an unresolved therapeutic dilemma despite extensive pre-clinical and clinical studies. The pathophysiology of the disease has been widely studied, and many factors that may be involved in progressive renal injury and cardiovascular risk associated with ARVD have been identified. However, therapies and clinical trials have focused largely on attempts to resolve renal artery stenosis without considering the potential need to treat the renal parenchyma beyond the obstruction. The results of these trials show a staggering consistence: although nearly 100% of the patients undergoing renal angioplasty show a resolution of the vascular obstruction, they do not achieve significant improvements in renal function or blood pressure control compared with those patients receiving medical treatment alone. It seems that we may need to take a step back and reconsider the pathophysiology of the disease in order to develop more effective therapeutic strategies. This mini-review discusses potential therapeutic alternatives that focus on the renal parenchyma distal to the vascular obstruction and may provide additional tools to enhance current treatment of ARVD.

A randomized, multi-center, prospective study comparing best medical treatment versus best medical treatment plus renal artery stenting in patients with hemodynamically relevant atherosclerotic renal artery stenosis (RADAR) - one-year results of a pre-maturely terminated study

BACKGROUND

The indications for conservative "best medical treatment" (BMT) versus additional renal artery stenting are a matter of ongoing debate. The RADAR study aimed to evaluate the impact of percutaneous renal artery stenting on the impaired renal function in patients with hemodynamically significant atherosclerotic renal artery stenosis (RAS).

METHODS

RADAR is an international, prospective, randomized (1:1) controlled study comparing BMT alone versus BMT plus renal artery stenting in patients with duplex sonographic hemodynamically relevant RAS. Follow-up assessments were at 2, 6, and 12 months and at 3 years. The primary endpoint was change in estimated glomerular filtration rate (eGFR) at 12 months.

RESULTS

Due to slow enrollment, RADAR was terminated early after inclusion of 86 of the scheduled 300 patients (28.7%). Change in eGFR between baseline and 12 months was 4.3 ± 15.4 ml/min/1.73 m² (stent group) and 3.0 ± 14.9 ml/min/1.73 m² (BMT group), p > 0.999. Clinical event rates were low with a 12-month composite of cardiac death, stroke, myocardial infarction, and hospitalization for congestive heart failure of 2.9% in the stent and 5.3% in the BMT group, p = 0.526, and a 3-year composite of 14.8% and 12.0%, p = 0.982. At 3 years, target vessel (re-)vascularization occurred in one patient (3.0%) in the stent group and in 8 patients (29.4%) in the BMT group.

CONCLUSION

In RADAR, outcomes of renal artery stenting were similar to BMT. These results have to be interpreted with the caveat that the study did not reach its statistically based sample size.

TRIAL REGISTRATION

Clinicaltrials.gov, NCT00640406. Registered on 17 March 2008.

Issues related to renal artery angioplasty and stenting

Renal artery stenosis may play a significant role in the pathogenesis of secondary hypertension, renal dysfunction, and flash pulmonary edema. Currently correction of renal arterial inflow stenosis is reserved for resistant hypertension patients who have failed maximal medical therapy, have worsening renal function and/or unexplained proximal congestive failure. With the recent advances in minimally invasive percutaneous stent placement techniques, open surgical revascularization has been largely replaced by renal artery stenting. The potential benefit of revascularization seemed intuitive; however, the initial enthusiasm and rise in the number of percutaneous interventions have been tempered by many subsequent negative randomized clinical trials that failed to prove the proposed benefits of the percutaneous intervention. The negative randomized trial results have fallen under scrutiny due to trial design concerns and inconsistent outcomes of these studies compared to pivotal trials undertaken under US Food and Drug Administration scrutiny. Treatment of atherosclerotic renal artery occlusive disease has become one of the most debatable topics in the field of vascular disease. The results from recent randomized clinical trials of renal artery stenting have basically limited the utilization of the procedure in many centers, but not every clinical scenario was covered in those trials. There are potential areas for improvement focusing mainly on procedural details and patient selection with respect to catheter based treatment of atherosclerotic renal artery stenosis. We believe, limiting patient selection, enrollment criteria and outcomes measured functioned to reduce the benefit of renal artery stenosis stenting by not enrolling patients likely to benefit. Future studies incorporating potential procedural improvements and that include patients more likely to benefit from renal stenting than were included in ASTRAL and CORAL are needed to more carefully examine specific patient subgroups so that “the baby is not thrown out with the bath water.” We also discuss several other concerns related to renal artery stenting which include diagnostic, procedure, indication, and reimbursement issues.

Issues related to renal artery angioplasty and stenting

Renal artery stenosis may play a significant role in the pathogenesis of secondary hypertension, renal dysfunction, and flash pulmonary edema. Currently correction of renal arterial inflow stenosis is reserved for resistant hypertension patients who have failed maximal medical therapy, have worsening renal function and/or unexplained proximal congestive failure. With the recent advances in minimally invasive percutaneous stent placement techniques, open surgical revascularization has been largely replaced by renal artery stenting. The potential benefit of revascularization seemed intuitive; however, the initial enthusiasm and rise in the number of percutaneous interventions have been tempered by many subsequent negative randomized clinical trials that failed to prove the proposed benefits of the percutaneous intervention. The negative randomized trial results have fallen under scrutiny due to trial design concerns and inconsistent outcomes of these studies compared to pivotal trials undertaken under US Food and Drug Administration scrutiny. Treatment of atherosclerotic renal artery occlusive disease has become one of the most debatable topics in the field of vascular disease. The results from recent randomized clinical trials of renal artery stenting have basically limited the utilization of the procedure in many centers, but not every clinical scenario was covered in those trials. There are potential areas for improvement focusing mainly on procedural details and patient selection with respect to catheter based treatment of atherosclerotic renal artery stenosis. We believe, limiting patient selection, enrollment criteria and outcomes measured functioned to reduce the benefit of renal artery stenosis stenting by not enrolling patients likely to benefit. Future studies incorporating potential procedural improvements and that include patients more likely to benefit from renal stenting than were included in ASTRAL and CORAL are needed to more carefully examine specific patient subgroups so that "the baby is not thrown out with the bath water." We also discuss several other concerns related to renal artery stenting which include diagnostic, procedure, indication, and reimbursement issues.

Renal artery stent in solitary functioning kidneys: 77% of benefit: A systematic review with meta-analysis

BACKGROUND

Solitary functioning kidney (SFK) is tough issue to address in clinical, mostly developed from renal artery stenosis (RAS) in adults. Although renal artery stent is widely used to help SFK patients, the efficacy of the stent is still disputable. This study is aimed at reviewing a series of SFK cases to draw a conclusion about the efficacy of renal artery stent.

METHODS

All related papers published in PubMed, Web of Science, EMBASE, and Cochrane Library were searched. Studies or subsets were included only if they satisfied certain criteria. The benefit rate which equaled the rate of improvement subjoining the rate of stabilization was calculated. All analyses were conducted with Stata version 12.0 (Stata Corporation, College Station, TX).

RESULTS

According to 7 papers on the efficacy of renal artery stent, 253 SFK patients were included. The result revealed that the renal artery stent could help SFK patients to improve or stabilize their renal function (RF). The benefit rate was 0.77, with 95% confidence interval between 0.72 and 0.83.

CONCLUSIONS

With proper patient selection, renal artery stent could benefit SFK patients with a percentage odd of 0.77 to improve or stabilize the RF.

Treatment of In-Stent Restenosis in Patients with Renal Artery Stenosis

PURPOSE

To determine clinical outcomes of patients treated for renal artery in-stent restenosis (ISR) with atherosclerotic renal artery stenosis.

MATERIALS AND METHODS

A retrospective review was performed of the clinical data of all patients who underwent renal artery stent placement for atherosclerotic renal artery stenosis from 1996 to 2009. Medical records of patients were reviewed for relevant clinical history, including blood pressure, antihypertensive medications, and renal function data before and after an intervention. In 1,052 patients, 1,090 renal artery stent placements were performed. Of these, 101 stents in 79 patients developed ISR, which was treated with either percutaneous transluminal angioplasty (PTA) or repeat stent placement. Procedural details, including modality of intervention, stent diameter, and time to restenosis, were recorded. Hypertensive agent and use of statins were recorded. Univariate analysis was performed to identify risk factors associated with restenosis after treatment of ISR.

RESULTS

Patients treated with repeat stent placement were 6.89 times more likely to lose patency after treatment than patients treated with PTA (P < .01). No additional clinical or procedural factor, including smoking history; presence of cardiac, renal, or metabolic disease; use of statin at time of ISR treatment; or diameter of treatment (stent or PTA), had a significant association with duration of stent or angioplasty patency.

CONCLUSIONS

Treatment of renal artery ISR with PTA among patients with atherosclerotic renal artery stenosis has a lower rate of subsequent ISR compared with repeat stent placement.