Treatment of renovascular hypertension with percutaneous transluminal angioplasty: experience in Spain

Outcomes Following the Endovascular Treatment of Renal Artery Stenosis Caused by Fibromuscular Dysplasia: A Systematic Review and Meta-Analysis

OBJECTIVE

Renal artery revascularization has been performed to improve blood pressure control and to cure hypertension in patients with renal artery fibromuscular dysplasia (RAFMD). We herein conducted a systematic review and meta-analysis of studies assessing outcomes associated with the treatment of hypertensive RAFMD patients via endovascular angioplasty in order to offer an up-to-date overview of the relative costs and benefits of this approach to revascularization in RAFMD patients.

METHODS

We systematically searched the PubMed and Embase databases and the Cochrane Central Register for Controlled Trials to identify relevant studies published as of January 15, 2020. Key outcomes of interest in these studies included technical success, the incidence of perioperative complications, cure rates, and overall improvement rates.

RESULTS

In total, we identified 36 relevant studies of 1916 total repairs conducted in 1191 patients. Of these included studies, 33 were retrospective, while 3 were prospective. The overall technical success rate across these studies was 94.3%. Rates of total, major, and minor complications in these pooled studies were 12.9%, 4.6%, and 7.4%, respectively. Pooled rates of cured hypertension and improved hypertension following angioplasty, defined according to study-specific criteria, were 37.0% [95% CI: 27.0%-47.0%] and 80.0% [95% CI: 75.0% to 84.0%], respectively, although these rates varied highly among studies. Cure rates for studies used current clinical definitions for substantial variations across studies. Cure rates in studies using current definitions of cured hypertension (blood pressure <140/90 mm Hg without treatment) were just 18.1% following angioplasty. Cure rates fell markedly with increasing mean patient age (OR associated with an increase in mean age of 10 years: -0.24 [95% CI: -0.44 to -0.04, P = 0.019] and with mean known duration of hypertension (OR associated with an increase in mean hypertension duration of 5 years: -0.09 [95% CI: -0.12 to -0.05, P = 0.001]).

CONCLUSIONS

These findings suggest that endovascular treatment yielded moderate benefits to RAFMD patients, with substantial variation across studies. The blood pressure outcome was strongly influenced by patient age.

Treatment of severe renal artery stenosis by percutaneous transluminal renal angioplasty and stent implantation: review of the pediatric experience: apropos of two cases

The clinical course of two children with mid-aortic syndrome and renal artery stenosis (RAS) who suffered from severe arterial hypertension is described. Hypertension was uncontrollable by antihypertensive medication and was managed by percutaneous transluminal renal angioplasty (PTRA) with stent implantation. The pediatric experience with PTRA is limited, and there are only few cases reported with additional stent implantation. Complications of these procedures are well known from experience with adult patients. However, since surgical revascularization may be technically difficult especially in small children, PTRA with or without stenting should be considered as a valuable treatment option in pediatric RAS.

[Interventional therapy in renal artery dissection due to renal artery PTA. Case report]

Percutaneous angioplasty of a renal artery stenosis may lead to dissection and acute thrombosis that may put the organ at risk. In this case, it should be discussed individually how to treat the patient and the decision on interventional therapy should be based on interdisciplinary consensus. Local fibrinolysis usually allows to recognize the cause of obstruction which then is the basis for further treatments. The case report presented in this article describes how a dissection involving two thirds of the renal artery and leading to significant obstruction may successfully be treated by means of interventional radiology.

Guidelines for the Reporting of Renal Artery Revascularization in Clinical Trials

Although the treatment of atherosclerotic renal artery stenosis with use of percutaneous angioplasty, stent placement, and surgical revascularization has gained widespread use, there exist few prospective randomized controlled trials (RCTs) comparing these techniques to each other or against the standard of medical management alone. To facilitate this process as well as help answer many important questions regarding the appropriate application of renal revascularization, well-designed and rigorously conducted trials are needed. These trials must have clearly defined goals and must be sufficiently sized and performed so as to withstand intensive outcomes assessment. Toward this end, this document provides guidelines and definitions for the design, conduct, evaluation, and reporting of renal artery revascularization RCTs. In addition, areas of critically necessary renal artery revascularization investigation are identified. It is hoped that this information will be valuable to the investigator wishing to conduct research in this important area.

Use of external iliac artery in renal revascularization surgery: long-term angiographic assessment

PURPOSE

The external iliac artery has physical characteristics, in particular, caliber and length, similar to those of the renal artery and would thus seem to be an ideal substitute for it. However, there are no studies in the literature designed to confirm this possibility. The present study was designed to demonstrate the feasibility of use of the external iliac artery as a substitute for the renal artery in surgical revascularization of renal artery fibrodysplasia and to assess the long-term biologic behavior of the external iliac artery so used.

METHODS

Twelve patients (11 female, 1 male), ages 1 to 43 years (mean, 24.4 years), with severe hypertension underwent aortorenal bypass grafting with use of the external iliac artery to treat preocclusive stenotic lesions (n = 7), complete occlusion (n = 3), or aneurysm (n = 2) of the renal artery. It was considered unnecessary to reestablish circulation in the donor limb in 2 patients (young children), and transposition of the ipsilateral internal iliac artery was performed in 9 patients; in the remaining patient circulation was reestablished with insertion of an iliofemoral prosthesis.

RESULTS

There were no operative deaths. In 1 patient nephrectomy was necessary because of occlusion of the graft as a consequence of technical complications. In 8 patients there was immediate normalization of blood pressure without aid of medication, and in the remaining 3 patients an antihypertensive drug was prescribed. Two patients were lost to follow-up; the other 9 were assessed with angiography at a mean of 8.8 years after the operation. All grafts were found to be in excellent condition, with no evidence of dilatation, kinking, twisting, anastomotic fibroplasia, or wall irregularities.

CONCLUSION

On the basis of this experience, the external iliac artery is confirmed as a substitute for the renal artery, and the excellent long-term results would seem to make it particularly useful in young patients with long life expectancy, such as those with renal artery fibrodysplasia.

Guidelines for the reporting of renal artery revascularization in clinical trials

Although the treatment of atherosclerotic renal artery stenosis with use of percutaneous angioplasty, stent placement, and surgical revascularization has gained widespread use, there exist few prospective randomized controlled trials (RCTs) comparing these techniques to each other or against the standard of medical management alone. To facilitate this process as well as help answer many important questions regarding the appropriate application of renal revascularization, well-designed and rigorously conducted trials are needed. These trials must have clearly defined goals and must be sufficiently sized and performed so as to withstand intensive outcomes assessment. Toward this end, this document provides guidelines and definitions for the design, conduct, evaluation, and reporting of renal artery revascularization RCTs. In addition, areas of critically necessary renal artery revascularization investigation are identified. It is hoped that this information will be valuable to the investigator wishing to conduct research in this important area.

Percutaneous revascularization of the renal arteries: predictors of outcome

PURPOSE

To identify predictors of clinical outcome after percutaneous revascularization of the renal arteries.

MATERIALS AND METHODS

In 63 patients, the therapeutic response was retrospectively assessed after percutaneous revascularization of the renal arteries indicated for hypertension (41.3%), renal failure (4.8%), or both (53.9%). All patients underwent percutaneous transluminal renal angioplasty, complemented by stent insertion in 30 patients. The authors analyzed the role of clinical and imaging factors, including scintigraphy, Doppler sonography, and angiography for predicting clinical success.

RESULTS

In the hypertensive population, there were three cures (5.6%), 26 improvements (48.1%), and 25 failures (46.3%). Among patients with renal insufficiency, 12 were improved (37.5%), 11 were stabilized (34.4%), and nine deteriorated (28.1%). Predictors of favorable outcome for hypertension were shorter duration of hypertension, higher diastolic blood pressure, fibromuscular dysplasia, abnormal Doppler study, higher percentage of angiographic stenosis, and lower grade of aortic atheromatous disease. Predictors of favorable outcome for renal failure were nondiabetic status, abnormal Doppler study, and higher percentage of angiographic stenosis. Abnormal Doppler and scintigraphic examinations predicted successful treatment of hypertension in 60% and 53.8% of cases, respectively, and renal insufficiency in 85% and 60% of cases, respectively.

CONCLUSION

Clinical and angiographic variables were the best predictors of therapeutic success for hypertension. Doppler sonography was useful in patients with renal failure.

Outpatient percutaneous transluminal renal artery angioplasty: a Canadian experience

PURPOSE

The authors performed a retrospective study of their experience and complication rate while performing outpatient percutaneous transluminal renal artery angioplasty (PTRA) during a 5-year period.

MATERIALS AND METHODS

From July 1992 to July 1997, 87 PTRAs were performed. Of these, 62 PTRA procedures were performed on 53 outpatients. In total, 66 arteries were dilated in 62 PTRA sessions using standard, established techniques. During the same period, only 25 PTRAs were performed on inpatients. Angioplasties were performed on those patients with demonstrated renal artery stenosis and poorly controlled hypertension and/or renal failure. Patients chosen for PTRA were picked by a team that included a vascular surgeon, a nephrologist, and a radiologist. Patients who were deemed suitable for an outpatient procedure were recommended by a nephrologist. Radiological input was sought at that time. Specific guidelines were used to select these patients who were otherwise healthy, well-orientated, and able to respond to an emergency situation. None of the subjects had significant risk factors. All were accompanied by an adult for the first 24 hours and all lived no more than an hour's travel time from a hospital. All were stable on discharge and were seen within 24 hours by a nephrologist.

RESULTS

The technical success rate, defined as a residual stenosis on imaging of less than 30% and/or by a pressure gradient of less than 10 mm Hg across the stenosis, was 85%. The early complication rate was 5.6%, including two patients who developed a localized hematoma. In all, four patients were admitted to the hospital rather than being discharged to home after an average of 4.2 hours of observation. The late complication rate was 3% and involved two patients. One patient, who reported pain after balloon deflation, was readmitted 6 hours after discharge with hypotension, and a diagnosis of renal artery rupture was confirmed with computed tomography. Another patient developed peripheral atheroemboli 20 days after the procedure.

CONCLUSION

Outpatient PTRA can be performed on selected patients. In this study, late complications occurred in only 3% of patients. Early complications were readily recognized in 5.6% of patients, and these patients were admitted for observation after the procedure.

Stents for atherosclerotic renovascular disease

There is extensive documentation of excellent clinical results with renal stents in patients who have technically failed angioplasty and who would have been expected to otherwise have a high incidence of clinical failure. In addition, the technical success of renal stents is vastly superior to that of conventional angioplasty in atherosclerotic renovascular disease, and stents have been a major factor in making the endovascular treatment of ASRVD both practical and reliable in experienced hands. Restenosis rates appear roughly equivalent or lower for stents versus PTA as far as can be determined without good comparative studies. Restenosis appears to be decreasing to 15%-20% in more recent series, perhaps because of the accumulation of knowledge regarding patient selection and techniques. It is, therefore, clear that the use of stents to treat technical failures of angioplasty will result in overall improved patency in the treated population; however, it remains to be determined whether stents should be routinely placed with the intention of inhibiting restenosis, in the presence of technically successful angioplasty with minimal residual stenosis or pressure gradient. Such a determination may require comparative study that is more complicated than a simple randomized comparison of angioplasty versus stents.

Four-year follow-up of Palmaz-Schatz stent revascularization as treatment for atherosclerotic renal artery stenosis

BACKGROUND

Stent revascularization is perceived as superior to balloon angioplasty and surgical revascularization, but the paucity of stent publications precludes even historical comparison with surgical data.

METHODS AND RESULTS

Palmaz-Schatz stent revascularization of renal artery stenosis was successfully performed on 163 consecutive patients for poorly controlled hypertension or preservation of renal function. Of these, 145 were eligible for > or =6-month clinical follow-up of the effect of the procedure on renal function, blood pressure control, number of antihypertensive medications, and survival. At 4 years, systolic and diastolic blood pressures significantly decreased (from 166+/-26 to 148+/-22 mm Hg and from 86+/-14 to 80+/-11 mm Hg, respectively; P<0.05), and blood pressure control was more facile in approximately half of the patients. Creatinine decreased or remained stable in approximately two thirds of the patients. The cumulative probability of survival was 74+/-4% at 3 years, with few deaths related to end-stage renal disease. Survival was good in patients with normal (92+/-4%) baseline renal function, fair (74+/-7%) in those with mildly impaired renal function, and poor (52+/-7%) in patients with elevated baseline creatinine levels (> or =2.0 mg/dL). The combination of impaired renal function and bilateral disease adversely affected survival.

CONCLUSIONS

Renal artery stent revascularization in the presence of normal or mildly impaired renal function had a beneficial effect on blood pressure control and a nondeleterious effect on renal function. Survival was adversely affected by renal dysfunction despite adequate revascularization. Early diagnosis and adequate revascularization before the onset of renal dysfunction could beneficially affect blood pressure control, preserve or prevent deterioration of renal function, and improve patient survival.

Renal artery angioplasty: technical results and clinical outcome in 320 patients

OBJECTIVE

To review the results of percutaneous transluminal renal artery angioplasty (PTRA), including technical success and clinical outcome, at Mayo Clinic Rochester.

DESIGN

We retrospectively reviewed our experience with 320 patients who underwent PTRA for stenosis of 396 arteries during a 14-year period.

MATERIAL AND METHODS

We reviewed medical records and angiograms of patients who underwent PTRA at Mayo Clinic Rochester between January 1980 and December 1993. The patients were divided into four groups, based on clinical history and angiographic appearance of the stenosing lesion: renal artery atherosclerosis (ASO group), fibromuscular dysplasia (FMD group), previous renal artery bypass or endarterectomy, and renal artery stenosis in a solitary kidney. Technical results of the PTRA were determined by evaluation of angiograms obtained before and after the procedure. Data on patient demographics, blood pressure, antihypertensive medications, and serum creatinine were recorded for the period preceding PTRA, after the procedure, and at last follow-up.

RESULTS

All groups had statistically significant reductions in mean arterial pressure and antihypertensive medications after PTRA. The percentage of patients who benefited after renal artery angioplasty was 70% for patients with ASO (8.4% cured), 63% for patients with FMD (22% cured), 53.8% for patients with prior surgical revascularization (23.1% cured), and 91.7% for patients with a solitary kidney (0% cured). No significant overall change in serum creatinine level was noted after the procedure in any group. Complications were comparable to those reported in other studies. The 30-day all-cause mortality rate was 2.2% for the current study, all deaths occurring in the ASO group.

CONCLUSION

PTRA rarely leads to a "cure" of renovascular hypertension but provides effective control of blood pressure and decreases the medication requirements in selected patients.

Follow-up of primary Palmaz-Schatz stent placement for atherosclerotic renal artery stenosis

A Palmaz-Schatz stent was successfully placed in 92 stenotic renal arteries (76 patients) for (1) hypertension in 62 (82%), and/or (2) chronic renal failure (serum creatinine > or = 1.5 mg/dl) and preservation of renal function in 39 (51%). Patients were followed to assess clinical and angiographic 6-month outcome. Angiography, performed in 45 of 62 eligible patients (73%) and in 56 of 74 treated arteries (76%), showed restenosis occurring in 14 renal arteries (25%). Serum creatinine improved or remained stable in 78% of patients. In patients with chronic renal failure, improvement or stability was observed in 55%. Blood pressure recordings significantly decreased for the entire cohort (systolic: 168 +/- 25 to 156 +/- 22 mm Hg, p < 0.0001; diastolic: 87 +/- 11 to 81 +/- 11 mm Hg, p < 0.005), and for hypertensive patients with normal creatinine (systolic: 179 +/- 20 to 155 +/- 23 mm Hg, p < 0.0001; diastolic: 92 +/- 9 to 83 +/- 12 mm Hg, p < 0.002). These follow-up data of a prospective, nonrandomized, observational study showed that stent recanalization of atherosclerotic renal artery stenoses was beneficial with regard to renal function and blood pressure response, and had a restenosis incidence of 25%.