Long-term outcome of surgical revascularization in ischemic nephropathy: normalization of average decline in renal function

Outcome following renal autotransplantation in renal artery stenosis

Introduction

With significant advances in the area of interventional radiology, angioplasty and stenting have become preferred first-line treatment in patients with significant renal artery stenosis. However, not all patients have favorable anatomy to undergo minimally invasive treatments, and reconstruction of the renal artery is an option. In select cases, either improved renal function or maintenance of existing function and sometimes resolution of hypertension can follow surgical treatment.

Material and Methods

This was a prospective observational study conducted from August 2010 to June 2016. Patients <45 years of age with uncontrolled hypertension secondary to renovascular hypertension (RVH) and refractory to medical management and renal arterial disease unfavorable for percutaneous intervention were included in the study. All patients were evaluated thoroughly using computed tomography angiography and diethylenetriaminepentaacetic acid renal scan. Patients underwent autotransplantation either into the right or left iliac fossa. Some kidneys required bench reconstruction of the renal artery and/or its branches before being implanted into either iliac fossa.

Results

Nine patients were included in the study. The mean age was 27 years. Seven were males and two were females. Five patients had bilateral renal artery stenosis. After autotransplantation, initially five patients became free of antihypertensive medicines, but on the follow-up, two patients showed rising trend of blood pressure. The evaluation revealed narrowing at anastomosis site in both patients with salvageable kidney function in one patient. Angioplasty with stenting was done in this patient while the second patient underwent secondary nephrectomy. At 2 years of follow-up, four patients required no antihypertensive medicines.

Conclusion

Autotransplantation can be a successful treatment of severe RVH and should be considered in patients with renal arterial disease unfavorable for percutaneous intervention.

Management of atherosclerotic renovascular disease: the effect of renal artery stenting on renal function and blood pressure

In the last few years, renal artery stenting has gradually evolved into one of the most important therapeutic modalities in the management of atherosclerotic renovascular disease. Stenting is nowadays preferred by a steadily increasing number of physicians, not only because of its significant contribution to blood pressure control, but also because of its documented ability to maintain, and even improve, renal function. At the same time, procedure-related morbidity and mortality rates are extremely low, while recurrent stenosis rates have been repeatedly reported to be minimal. Percutaneous transluminal renal angioplasty (PTRA) and stenting are nowadays considered by many physicians to be the treatment of choice for atherosclerotic renovascular disease.

Effect of renal artery stenting on renal function in patients with ischemic nephropathy

The aim of this study was to evaluate the effects of stenting on blood pressure and renal functions in azotemic patients with proximal/ostial atherosclerotic renal artery stenosis. Thirteen azotemic patients (5 females, 8 males, average age, 62.7 +/- 8.3 years) who had renal artery stenosis were included in the study. Their blood pressure, estimated glomerular filtration rate (EGFR), and creatinine levels were measured at baseline and during follow-up. Stents were implanted successfully in all of the cases. The average stent diameter and stent length were 7.2 +/- 0.5 mm and 17.2 +/- 3.4 mm, respectively. Antihypertensive drug was abandoned in 1 (7.6%) patient, reduced in 10 patients (76.9%), and not changed in 2 (15.3%) patients. Significant improvement was observed in the mean serum creatinine level at the 12th month when compared with baseline (2.56 +/- 0.88; 1.83 +/- 0.62, P < 0.001). EGFR was 18.38 +/- 4.64 before the procedure and 22.67 +/- 3.81 during follow-up (P < 0.0001). According to the GFR criteria, renal function was determined to be worse in 1 (7.6%) patient, stabilized in 2 (15.3%), and improved in 10 (76.9%) patients. One patient died during the follow-up period. Angiographic restenosis was observed in 2 (15.3%) patients. Follow-up major events were observed in 3 (23%) patients. Stenting azotemic patients with renal artery stenosis is a reliable and effective procedure for achieving an improvement in renal function.

Percutaneous Transluminal Renal Angioplasty (PTRA) and Surgical Revascularisation in Renovascular Disease—A Retrospective Comparison of Results, Complications, and Mortality

OBJECTIVE

To evaluate results, complications and mortality following percutaneous transluminal renal angioplasty (PTRA) and open surgical revascularisation for renovascular disease.

METHODS

A retrospective evaluation of 381 renovascular patients (median age 64, range 9-99 years, 152 women) treated at Malmö University Hospital during 1987-1996. Two hundred and sixty-two (69%) of the patients were treated with PTRA, 106 (28%) with open revascularisation.

RESULTS

Thirty-day mortality was 2% in the PTRA group and 9% after open surgery (p<0.001). There were no differences between groups concerning the number of re-do procedures, but first re-do was performed after seven (IQR 3-14) months in the PTRA group, and after 15 (IQR 10-44) months after open revascularisation (p<0.0001). After a median follow-up of 4 months (IQR 0-13) systolic and diastolic blood pressure (BP) had decreased (p<0.0001) in both groups. The number of antihypertensive drugs was reduced (p<0.0001) and S-creatinine levels were unchanged in both groups. Long-time survival assessed with log-rank analysis was better (p<0.01) in the PTRA group. The risk ratio for death with open revascularisation was 1.69 (p<0.01).

CONCLUSIONS

In this retrospective comparison, PTRA was as effective as open revascularisation, with lower complication rate and lower early and long-time mortality, but with shorter time to first re-do.

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.

Spontaneous dissection of renal artery: long-term results of extracorporeal reconstruction and autotransplantation1

PURPOSE

We undertook this study to assess the outcome of spontaneous dissection of the renal artery and its branches surgically treated with extracorporeal reconstruction and autotransplantation.

SUBJECTS

Between 1975 and 1996, 15 consecutive patients (19 kidneys) with spontaneous renal artery dissection underwent renal artery reconstruction. Fourteen patients had accelerated hypertension. Five patients had impaired renal function. In 14 patients the dissection was associated with fibrodysplasia, and in 1 patient it was related to arteriosclerosis.

INTERVENTION

In 17 kidneys extracorporeal reconstruction and autotransplantation was used. The renal artery of 1 kidney was reconstructed in situ. One primary nephrectomy was performed.

RESULTS

There were no operative deaths or major morbidity. All but 1 reconstruction was successful (94.4%). Results at follow-up (range, 1-8 years) were favorable in 14 patients; 79% had satisfactory blood pressure control, and all patients had normal renal function, including those with impaired renal function preoperatively.

CONCLUSIONS

Extracorporeal reconstruction and autotransplantation can be effectively used in patients with spontaneous renal artery dissection located in or extending into the distal branches. Early recognition and appreciation of the clinical presentation of spontaneous renal artery dissection are important.

Percutaneous stenting of incidental unilateral renal artery stenosis: decision analysis of costs and benefits

PURPOSE

To determine the incremental cost-effectiveness of prophylactic percutaneous transluminal angioplasty with stent placement (PTA-S) in patients with incidentally discovered, asymptomatic renal artery stenosis (RAS) compared to delaying PTA-S until patients develop refractory hypertension or renal insufficiency (therapeutic PTA-S).

METHODS

The Markov decision analysis model was used to determine the incremental cost per quality adjusted life year (QALY) saved for prophylactic PTA-S as compared to therapeutic PTA-S in a hypothetical cohort of patients with 50% unilateral atherosclerotic RAS followed from age 61 to death.

RESULTS

Prophylactic PTA-S compared to therapeutic PTA-S results in more QALYs/patient (10.9 versus 10.3) at higher lifetime costs ($23,664 versus $16,558). The incremental cost effectiveness of prophylactic PTA-S was estimated to be $12,466/QALY. Prophylactic stenting was not cost effective (>$50,000/QALY) if the modeled incidence of stent restenosis exceeded 15%/year and the incidence of progression in the contralateral renal artery was <2% of arteries/year.

CONCLUSIONS

PTA-S of incidental, asymptomatic unilateral RAS may improve patients' quality of life at an acceptable incremental cost. However, this technology should be used hesitantly until a randomized comparison confirms its effectiveness.

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.

Long-term renal function preservation after renal artery stenting in patients with progressive ischemic nephropathy

We assessed the long-term effect of successful renal artery stent revascularization on renal function, blood pressure control, and survival in patients with progressive renal dysfunction due to ischemic nephropathy. Ischemic nephropathy presents a potentially serious risk of complete loss of renal function. Surgical renal revascularization is associated with significant risk of mortality/morbidity in this patient population. The potential role and long-term effect of renal artery stent revascularization in this patient population is not well defined. A cohort of 51 patients (mean age, 72 years; 52.9% men) with progressive azotemia, defined as a preprocedure serum creatinine (Scr) value of >or= 1.5 mg/dl and a negative slope of the reciprocal 1/Scr curve during the 12 months preceding revascularization, underwent successful primary stent deployment in 93 atherosclerotic renal artery lesions (42 bilateral, 9 solitary kidneys). Estimated glomerular filtration rate (EGFR) and serum creatinine values, blood pressure, antihypertensive medication requirements, and survival rates were monitored over a mean of 30-month follow-up. Renal artery duplex Doppler or renal angiography were performed at a mean of 13 months (range, 7-15 months) to assess stent patency. Stent implantation was successful in 92/93 (98.9%) stenotic renal arteries (mean preprocedure serum creatinine 2.3 +/- 0.9 mg/dl; range, 1.5-8.2 mg/dl). Forty-seven patients were eligible for 30-month follow-up of the procedural effect on renal function, blood pressure control, number of antihypertensive medications, and survival. At 1-year follow-up, the slope of the 1/Scr curve increased and the EGFR values significantly improved compared to preprocedure values (19.9 +/- 6.2 to 26.8 +/- 10.1 ml/min; P < 0.0001), serum creatinine decreased from the mean preprocedure value to 1.75 +/- 0.69 mg/dl (P < 0.001), with renal function improvement or stabilization observed in 94% of patients; three patients (7.3%) required permanent hemodialysis during the 30-month follow-up period. Systolic and diastolic blood pressure significantly decreased (from 177 +/- 28 to 148 +/- 25 mm Hg and from 92 +/- 15 to 78 +/- 14 mm Hg, respectively; P < 0.001) with fewer antihypertensive medications required to control blood pressure (3.5 +/- 0.9 vs. 1.9 +/- 1.3; P < 0.001). The patient survival rate after 30-month follow-up was 87%, with three deaths related to end-stage renal failure. Renal artery stent revascularization reversed progressive renal dysfunction within the first 12 months and maintained the improved level of renal function at 30-month follow-up while improving blood pressure control and reducing the number of antihypertensive medication requirements. Renal stent revascularization should be considered a valid therapeutic option for the long-term treatment of ischemic nephropathy.

Prospective multicentre study of the natural history of atherosclerotic renal artery stenosis in patients with peripheral vascular disease

BACKGROUND

Many patients with peripheral vascular disease have coincident renal artery stenosis. The present study characterized the natural history of the condition.

METHODS

Some 98 patients (71 men) with more than 50 per cent atherosclerotic renal artery stenosis (unilateral 64, bilateral 34) were recruited prospectively. Measurements of serum creatinine, blood pressure and renal size were recorded at baseline and every 6 months, for a minimum of 2 years.

RESULTS

Data were available for 85 patients with a minimum follow-up of 2 years. The mean age was 71 (range 51-87) years. All 52 patients with unilateral renal artery stenosis were managed conservatively (group 1); 21 of the 33 patients with bilateral disease had no intervention (group 2) and the remaining 12 had angioplasty or reconstruction (group 3). The overall mortality rate was 32 per cent at 2 years (27 patients) and this was similar in all three groups. In only three patients was death related directly to renovascular disease; coronary disease accounted for the majority of deaths. All three patients who needed dialysis died within 1 year. In survivors from groups 1 and 3 there was a significant increase in serum creatinine concentration at follow-up. Blood pressure did not increase significantly.

CONCLUSION

Patients with renal artery stenosis and peripheral vascular disease had a poor prognosis, but this was not directly attributable to renal failure.

Primary renal artery stenting: characteristics and outcomes after 363 procedures

BACKGROUND

Stenting improves the acute results of percutaneous balloon angioplasty for atherosclerotic renal artery stenosis. Predictors of benefit and angiographic restenosis are not well understood. We describe the technical and clinical success of renal artery stenting in a large consecutive series of patients with hypertension or renal insufficiency. We identify clinical, procedural, and anatomic factors that might influence outcome, restenosis, and survival.

METHODS

Primary renal artery stenting was performed in 300 consecutive patients who underwent 363 stent procedures in 358 arteries. Angiograms were analyzed quantitatively. Clinical and angiographic follow-up data are available after a median of 16.0 months.

RESULTS

At baseline, 87% of patients had hypertension, and 37% had chronic renal insufficiency. The mean age was 70 years (interquartile range 63.1-74.6) years. The stenosis was unilateral in 49% and bilateral in 48% and involved a solitary functioning kidney in 3.6%. The stenting procedure was successful in all attempts. There were no procedural deaths or emergency renal surgical procedures. Postprocedure azotemia was seen in 45 of 363 (12%) procedures but persisted in only 6 patients (2%), all of whom had baseline renal insufficiency. Systolic and diastolic blood pressures were significantly reduced (systolic blood pressure from 164.0 +/- 28.7 to 142.4 +/- 19.1 mm Hg, P <.001). At follow-up, 70% of patients had improved blood pressure control regardless of renal function. In patients with baseline renal insufficiency, 19% had improvement in serum creatinine levels at follow-up, 54% had stabilization, and 27% had deterioration. Follow-up mortality was 10% and was predicted by baseline creatinine levels (odds ratio 1.72 for each 1 mg/dL creatinine increment, 95% confidence interval 1.13-2.49) and extent of coronary artery disease (odds ratio 1.66 for each diseased coronary artery, 95% confidence interval 1.03-2.67). Angiographic restenosis was found in 21% of 102 patients overall and was less common (12%) in arteries with a reference caliber >4.5 mm (P <.01 vs caliber <4.5 mm). Neither poststenotic dilation nor severity of angiographic stenosis predicted clinical outcome.

CONCLUSIONS

Primary renal artery stenting can be performed safely with nearly uniform technical success. The majority of patients with hypertension or renal insufficiency derive benefit. Follow-up mortality is 5-fold higher in patients with baseline renal insufficiency. Clinical and angiographic features did not predict blood pressure or renal functional outcome. Restenosis is more common in renal arteries with a reference caliber less than 4.5 mm.

Ischemic nephropathy: clinical characteristics and treatment

Ischemic nephropathy is a long-term cause of hypertension and renal failure. Although its real incidence is unknown, ischemic nephropathy is growing because of the increased mean age of the population and the greater prevalence of hypertensive and diabetic populations. This review describes the clinical profile of afflicted patients. Atherosclerosis in different vascular beds is common in these patients. The evolution of ischemic nephropathy is generally progressive, although some patients present with acute renal failure, either secondary to the administration of angiotensin-converting enzyme inhibitors or caused by thrombosis of the renal arteries. Revascularizing surgery may stabilize or improve renal function, even in patients with nonfunctioning kidneys. The results obtained with intraluminal angioplasty are worse, with a high percentage of restenosis. Placement of an endoprothesis is recommended when the lesions affect the ostium or proximal third of the artery. This complex disease typically affects multiple organs, thus making individual assessment essential.