Chronic renal artery occlusion: nephrectomy versus revascularization

Altered immune cell phenotypes within chronically ischemic human kidneys distal to occlusive renal artery disease

Renal artery stenosis (RAS) is a major cause of ischemic kidney disease, which is largely mediated by inflammation. Mapping the immune cell composition in ischemic kidneys might provide useful insight into the disease pathogenesis and uncover therapeutic targets. We used mass cytometry (CyTOF) to explore the single-cell composition in a unique data set of human kidneys nephrectomized due to chronic occlusive vascular disease (RAS, n = 3), relatively healthy donor kidneys (n = 6), and unaffected sections of kidneys with renal cell carcinoma (RCC, n = 3). Renal fibrosis and certain macrophage populations were also evaluated in renal sections. Cytobank analysis showed in RAS kidneys decreased cell populations expressing epithelial markers (CD45-/CD13+) and increased CD45+ inflammatory cells, whereas scattered tubular-progenitor-like cells (CD45-/CD133+/CD24+) increased compared with kidney donors. Macrophages switched to proinflammatory phenotypes in RAS, and the numbers of IL-10-producing dendritic cells (DC) were also lower. Compared with kidney donors, RAS kidneys had decreased overall DC populations but increased plasmacytoid DC. Furthermore, senescent active T cells (CD45+/CD28+/CD57+), aged neutrophils (CD45+/CD15+/CD24+/CD11c+), and regulatory B cells (CD45+/CD14-/CD24+/CD44+) were increased in RAS. RCC kidneys showed a distribution of cell phenotypes comparable with RAS but less pronounced, accompanied by an increase in CD34+, CD370+, CD103+, and CD11c+/CD103+ cells. Histologically, RAS kidneys showed significantly increased fibrosis and decreased CD163+/CD141+ cells. The single-cell platform CyTOF enables the detection of significant changes in renal cells, especially in subsets of immune cells in ischemic human kidneys. Endogenous pro-repair cell types in RAS warrant future study for potential immune therapy.NEW & NOTEWORTHY The single-cell platform mass cytometry (CyTOF) enables detection of significant changes in one million of renal cells, especially in subsets of immune cells in ischemic human kidneys distal to renal artery stenosis (RAS). We found that pro-repair cell types such as scattered tubular-progenitor-like cells, aged neutrophils, and regulatory B cells show a compensatory increase in RAS. Immune cell phenotype changes may reflect ongoing inflammation and impaired immune defense capability in the kidneys.

Role of late renal revascularization in functional renal salvage

The duration that renal parenchyma will tolerate ischemia has continued to be debated. We have reported the cases of three patients who had undergone revascularization procedures with successful return of baseline renal function after prolonged renal artery occlusion of 14 days to 3 months. These cases highlight that aggressive revascularization can lead to successful renal salvage in selected patients. We examined the characteristics of these patients and those of others in the literature and reviewed the factors favoring recovery.

Renal salvage using stent graft placement after acute renal artery occlusion with prolonged ischemic time

Purpose

To describe a patient with acute renal artery occlusion who underwent successful revascularization procedure after experiencing a protracted ischemic period, which resulted in successful retrieval of renal function.

Case report

A 58-year-old male with a history of left renal artery stenosis and stent graft placement presented with symptoms of chest pain, shortness of breath, and flank pain. The patient was admitted to the Intensive Care Unit with the diagnosis of multiorgan failure and subsequent anuria that led to the initiation of hemodialysis. Computed tomography angiography demonstrated an aortic occlusion along with bilateral proximal renal artery occlusion with reconstitution of the mid to distal renal arteries via collateralization. The patient underwent angioplasty with bilateral renal artery stent-graft placement and successful revascularization of proximal renal arteries. Post-operatively, his renal function and urine output improved, and the patient was able to be weaned off hemodialysis along with the benefit of concurrent amelioration of his renovascular hypertension.

Conclusion

For select patients with renal artery occlusion, revascularization of the renal arteries may result in dialysis independence and stabilization of renovascular hypertension, despite prolonged time of ischemia.

Successful endovascular treatment of chronic renal artery occlusion: a preliminary retrospective case series including 15 patients

PURPOSE

To evaluate in a retrospective, single-center, case series if percutaneous transluminal renal angioplasty/stenting of chronic renal artery occlusion is beneficial to renal function and blood pressure control, which remains controversial.

METHODS

Data from 15 consecutive patients with renal artery stump who underwent successful percutaneous transluminal renal angioplasty/stenting only for unilateral chronic renal artery occlusion at our center from January 2007 to February 2018 and completed follow-up were retrospectively evaluated. Of the 15 patients, 14 (93.3%) were treated with stenting and 1 with only balloon angioplasty. Estimated glomerular filtration rate (eGFR) was calculated using the Modification of Diet in Renal Disease (MDRD) formula corrected for Chinese, and changes in blood pressure and need for antihypertensive medications were recorded.

RESULTS

At median 1.5-year (interquartile range 0.5-5.0) follow-up, restenosis rate was 20.0%. Renal function improved or remained stable in 26.7% and 53.3% of patients, respectively, and blood pressure normalized or improved in 13.3% and 40.0% of patients, respectively. Young patients with Takayasu's arteritis or fibromuscular dysplasia appeared to benefit the most from revascularization.

CONCLUSIONS

In this preliminary retrospective series of select patients with renal artery stump, endovascular treatment of chronic renal artery occlusion appeared to preserve renal function and improve blood pressure.

Renal Artery Stenosis: Optimal Therapy and Indications for Revascularization

Atherosclerotic renal artery stenosis (ARAS) is associated with increased cardiovascular risk and overall mortality. Manifestations of ARAS include resistant or malignant hypertension, progressive deterioration of renal function, and cardiac dysfunction syndromes of flash pulmonary edema and angina. Diagnosis rests upon non-invasive studies such as duplex ultrasonography and is confirmed using invasive renal arteriography. Regardless of the severity of ARAS, management of this entity has been a topic of contentious debate. For over two decades, the use of percutaneous revascularization to treat ARAS has been studied with various clinical trials. Though case series seem to demonstrate favorable clinical response to revascularization, the overwhelming majority of randomized clinical trials have not mirrored a robust outcome. In these trials, poor correlation is noted between the reduction of stenosis and the improvement of renovascular hypertension and glomerular filtration rate, and decrease in cardiovascular outcomes and mortality. With dichotomizing results, the explanation for these discrepant findings has been attributed to improper trial design and inappropriate patient selection. An overview of the treatment options available will be provided, with a focus on the methodology and design of clinical trials investigating the efficacy of percutaneous revascularization. Emphasis is placed on appropriate patient selection criteria, which may necessitate the use of hemodynamic lesion assessment and clinical correlation based on individualized care. When clinical equipoise exists between optimal medical therapy and revascularization, the current paradigm supports ongoing medical therapy as the treatment of choice. However, renal artery stenting remains a viable therapeutic option for those who continue to have clinical syndromes consistent with renal hypoperfusion while adequately treated with optimal medical therapy. Despite observational studies suggesting clinical benefit for this specific patient population, there remains a paucity of randomized clinical trial data. Further trials targeting the patients who are inadequately treated with optimal medical therapy need to be undertaken to confirm the efficacy of revascularization.

Recovery of Renal Function after Prolonged Anuria in Acute Suprarenal Aortic Occlusion

Acute suprarenal aortic occlusion is a rare but often catastrophic event. Despite immediate treatment, mortality and morbidity are high. We present a case of acute suprarenal aortic occlusion presenting with renal failure and dyspnea but without lower limb ischemia. Diagnosis was initially not taken in consideration. The patient required hemodialysis and temporary mechanical ventilation. After 13 days, an abdominal ultrasound was performed which revealed thrombosis of the suprarenal abdominal aorta. Suprarenal aortic thrombectomy was performed followed by aortobi-iliac bypass grafting. Diuresis returned 4 hr after surgery, and the patient fully recovered. Thorough review of the literature revealed only 8 cases of acute suprarenal aortic occlusion. Only 3 patients survived. To our knowledge, this is the first reported case of acute suprarenal occlusion, in which renal function could be restored after a 14-day period of anuria. The case illustrates that in select cases with prolonged acute renal failure aortorenal revascularization can be performed successfully.

Reversible dialysis-dependent renal failure due to undiagnosed renovascular disease

Renovascular disease (RVD) can present with resistant hypertension, acute or rapidly progressive renal failure and occasionally nephrotic proteinuria. Revascularization plays an important role in controlling blood pressure and preserving renal function. It is widely believed that delay in revascularization would result in irreversible loss of renal function. However, we report a favorable outcome despite delayed revascularization in two patients of RVD- one presenting with recurrent flash pulmonary edema and other with progressive renal failure. The former's serum creatinine returned to normal despite 3 months of anuria and the latter became dialysis-independent despite 2 months of progressive decline in renal function. Both remain dialysis-free 3 years after surgery.

Percutaneous revascularization of occluded renal arteries in the setting of acute renal failure

Abstract

We report the case of a 60-year-old patient with acute renal failure and occluded bilateral renal arteries presenting with acute pulmonary edema and non-ST segment elevation myocardial infarction. The patient required renal replacement therapy with hemodialysis and was subsequently successfully treated with bilateral renal artery stent placement. Marked improvement in renal function was noted within 1 week with freedom from the need for renal replacement therapy at 4 months of follow-up.

Effect of hospital volume on in-hospital mortality for renal artery bypass

BACKGROUND

A recent report determined that the nationwide mortality for renal artery bypass (RAB) is surprisingly high-10%. We hypothesized that operative mortality for RAB is related to the volume of such operations performed in each center.

METHODS

The Nationwide Inpatient Sample was analyzed to identify patients undergoing RAB for the years 2000-2005. In-hospital mortality for RAB was compared between hospitals.

RESULTS

During the study period, RAB was performed on 7413 patients with an overall in-hospital mortality of 9.6%. The multivariate logistic regression analyses revealed that after adjusting for surgical risk, increasing hospital volume was significantly associated with decreased in-hospital mortality for RAB (odds ratio 0.98; 95% confidence interval, 0.96-0.99; P=.015).

CONCLUSIONS

Patient risk profile and hospital volume are critical determinants of in-hospital mortality for RAB, which should be factored into decision making for patients requiring intervention for renovascular disease.

Coronary bypass procedures in patients with renal artery stenosis

BACKGROUND AND AIM OF THE STUDY

We present our experience on patients with renal artery stenosis undergoing myocardial revascularization procedures.

METHODS

Eighteen patients with varying degrees of renal artery stenosis were operated for coronary artery bypass grafting between 1996 and 2003. The overall incidence was 0.15%. There were nine male and nine female patients with a mean age of 62 +/- 8.2 (40-72 years). Four had bilateral and eight had significant unilateral (>50%) renal artery stenoses. Preoperatively, three patients had renal arterial intervention (stenting), and one patient was on hemodialysis. The mean preoperative creatinine value was 2.6 +/- 2.7 mg/dL (range 0.7 to 9.3). The patients were followed medically: two patients underwent off-pump coronary bypass grafting and the others were operated on-pump.

RESULTS

There was only one mortality and two patients required hemodialysis postoperatively. The postoperative mean creatinine values were 3.4 +/- 4.9 mg/dL (range 1.0 to 12.5). No electrolyte imbalances were noted except that one case revealed a transient metabolic acidosis. Five patients required inotropic support with dopamine and two needed diuretic infusions. Only five patients demonstrated a refractory hyper tensive period postoperatively.

CONCLUSIONS

The concomitant correction of renal artery stenosis with CABG is usually not necessary, but the principles for renovascular diseases must be kept in mind and individually oriented strategies must be planned.

Intervention for renal artery stenosis: endovascular and surgical roles

The treatment options for renal artery stenosis include bypass surgery, surgical endarterectomy, or balloon angioplasty with/without stenting. Each of these procedures is delivered today with differing frequency, morbidity/mortality, and outcomes. The procedure most applicable to patients with atherosclerotic disease is percutaneous transluminal renal angioplasty with stenting. Stents prevent plaque recoil, minimizing early restenosis, and the relatively large size of the renal artery (5-7 mm) minimizes late stent restenosis rates. The clinical features that help predict a favorable response to intervention are reviewed. In short, intervention provides a durable means to control renovascular hypertension, ischemic nephropathy, and congestive heart failure due to poor renal volume control.

Asymptomatic renal infarction, due to fibromuscular dysplasia, in a young woman with 11 years of follow-up

We report a 27-year-old woman with renovascular hypertension, renal infarction, and hepatic artery aneurysm due to fibromuscular dysplasia. The patient was first noted to have renal artery aneurysm and hepatic artery aneurysm at the age of 17. The renal infarction was asymptomatic and was incidentally detected by magnetic resonance imaging (MRI) examination. Because of the rather peripheral location of the aneurysms, percutaneous transluminal renal artery angioplasty was considered inappropriate. This case suggests the need for long-term and periodical follow-up of patients with fibromuscular dysplasia.

Sustained beneficial effects on blood pressure during long time retrospective follow-up after endovascular treatment of renal artery occlusion

We retrospectively evaluated short- and long-term effects of percutaneous transluminal renal angioplasty (PTRA) with or without stent placement of renal artery occlusion (RAO) upon blood pressure (BP), serum (s)-creatinine, and the need for antihypertensive treatment in 34 RAO patients who underwent PTRA during 1996-2002. In 24/34 (71%) treatment was considered technically successful, 22/24 (92%) were treated with PTRA + stent, two with only PTRA. Patients were followed for mean 2.6 (range 0-8) years, during which 14/34 (41%) patients died. In all 34 patients, systolic and diastolic BP (SBP and DBP) before treatment were 184 +/- 30/95 +/- 15 mmHg and had decreased at discharge (to 157 +/- 21/80 +/- 10 mmHg; P < 0.001 for both SBP and DBP), and remained lower after 1 year (154 +/- 20/83 +/- 7 mmHg; P < 0.001 for SBP and P < 0.01 for DBP), and at last follow-up (148 +/- 20/80 +/-12 mmHg; P < 0.001 for both SBP and DBP). No changes occurred in s-creatinine or the number of antihypertensive drugs. Similar results were seen in the subgroup of 24/34 (71%) patients in whom treatment was technically successful. Among the 24 patients undergoing technically successful PTRA, absence of nephrosclerosis (P = 0.035) and a shorter duration of hypertension (P = 0.020) predicted favourable clinical outcome. No adverse effects upon s-creatinine or the need for antihypertensive medication were seen in patients in whom treatment was considered a technical failure. Seven of these patients were treated with PTRA of another renal artery than the occluded, or with embolisation. In conclusion, RAO can be treated with endovascular techniques. Technically successful results with decreasing blood pressure levels were obtained in 71% of patients.

Renal revascularization in Takayasu arteritis–induced renal artery stenosis

PURPOSE

This study was undertaken to define the long-term effects of renal revascularization on blood pressure, and renal and cardiac function in patients with Takayasu arteritis-induced renal artery stenosis (TARAS).

METHODS

Twenty-seven patients (25 women; mean age, 27 years) with TARAS underwent intervention. Primary, primary assisted, and secondary patency rates were determined, and the late effects on blood pressure, renal and cardiac function, and survival were analyzed.

RESULTS

All patients had hypertension (mean blood pressure, 167/99 mm Hg; 2.5 antihypertensive medications per patient). Mean estimated glomerular filtration rate in patients not receiving hemodialysis was 76 mL/min, and in five patients serum creatinine concentration was greater than 1.5 mg/dL. Three patients were hemodialysis-dependent, and two had intractable congestive heart failure. Forty interventions were performed, including 32 aortorenal bypass procedures, two repeat implantations, four nephrectomies, and two transluminal angioplasty procedures. Postoperative morbidity was 19%. There were no deaths. During follow-up (mean, 68 months), three graft stenoses, all due to intimal hyperplasia, and three graft occlusions occurred. Two of three graft stenoses were successfully revised. At 1, 3, and 5 years of follow-up, primary patency was 87%, 79%, and 79%, respectively; primary assisted patency was 93%, 89%, 89%, respectively; and secondary patency was 93%, 89%, and 89%, respectively. Intervention resulted in a decrease in blood pressure to a mean of 132/79 mm Hg (P<.0001), and the need for antihypertensive medications was reduced to one per patient (P<.01). Mean glomerular filtration rate increased to 88 mL/min (P<.005), and two patients no longer required hemodialysis. Congestive heart failure resolved in both patients, and did not recur. There were three deaths during follow-up, with 5-year and 10-year actuarial survival of 96% and 80%, respectively.

CONCLUSIONS

Renal revascularization to treat TARAS is durable, has a salutary effect on blood pressure, and enhances long-term renal and cardiac function. This response establishes renal revascularization as a successful and durable intervention for TARAS, and a benchmark to which other therapies should be compared.

Revisiting the role of nephrectomy for advanced renovascular disease

BACKGROUND

Despite the advances in antihypertensive therapy and renal revascularization, there remains a group of patients in whom renovascular disease leads to renal atrophy and treatment-resistant hypertension.

METHODS

We performed an observational cohort study in which we reviewed blood pressures, renal function, and predictors of response in 74 patients who underwent nephrectomy of a small kidney for uncontrolled hypertension between 1990 and 2000.

RESULTS

The median age of the patients was 65 years; 43 (58%) were women. Thirty-five patients (47%) underwent nephrectomy as part of combined revascularization of the contralateral kidney. Associated atherosclerotic diseases were common (28% to 49%), as were prior renal revascularization (21 [28%]) and hypertensive urgency/emergencies (23 [31%]). The mean (+/- SD) long axis of the affected kidney was 8 +/- 2 cm, and the mean function of the kidney (based on radioisotope renography) was 12% +/- 11% of total renal function. The average systolic blood pressure fell from 168 +/- 19 mm Hg to 136 +/- 18 mm Hg (P <0.0001) and diastolic blood pressure declined from 88 +/- 10 mm Hg to 76 +/- 9 mm Hg (P <0.0001) at the most recent available clinic visit (mean follow-up, 4.1 +/- 2.6 years). In addition, the number of antihypertensive medications decreased from 3.2 +/- 1.1 to 2.2 +/- 1.5 (P <0.0001). Renal function remained stable. Results were similar (preoperative blood pressure of 165/88 mm Hg taking three medications to 137/77 mm Hg taking two medications) among the 39 patients who had a nephrectomy without contralateral revascularization.

CONCLUSION

Our results suggest that in selected patients with resistant hypertension and renal artery disease that has resulted in atrophic kidneys with reduced function, nephrectomy can improve blood pressure control without further loss in overall renal function.

Renal vein renin measurements accurately identify renovascular hypertension caused by total occlusion of the renal artery

OBJECTIVE

To assess the usefulness of indexes derived from renal vein renin measurements.

DESIGN

A 12-year prospective study.

SETTING

A tertiary institutional referral centre.

PATIENTS AND METHODS

Between 1988 and 2000, we studied 152 consecutive hypertensive patients with a high pre-test probability of renovascular hypertension (RVH). RVH was diagnosed retrospectively on the basis of reduction in blood pressure after correction of ischaemia at follow-up. Renal vein renin measurements were used to calculate the ratios: Visch/Vctl (renal vein renin ratio; RVRR); Vctl/Viivc; (Visch - Viivc)/Viivc; (Vctl - Viivc)/Viivc, where Visch and Vctl indicate plasma renin activity (PRA) in the ischaemic and contralateral renal veins, respectively, and Viivc denotes PRA in the infrarenal inferior vena cava. A receiver operator characteristics (ROC) curve analysis was used to determine the cut-off value of renal vein renin measurement indexes that provided the best discrimination between patients with and without RVH and to identify patients with RVH caused by total occlusion of the renal artery.

RESULTS

Sixty-seven patients were diagnosed as having RVH: 51 had significant renal artery stenoses (RVH non-occluded) and 16 had total renal artery occlusion (RVH occluded). Of the remaining 85 patients in whom RVH was excluded (non-RVH group), 27 had reno-parenchymal hypertension and 58 had essential hypertension. Of the renal vein renin measurement indexes, only RVRR and (Visch - Viivc)/Viivc in RVH-occluded patients differed significantly (P < 0.005) from those in the non-RVH group and showed the best performance by ROC curve analysis. This analysis also showed that, at any cut-off value, RVRR was far more accurate for identification of RVH-occluded patients than for identification of RVH non-occluded patients, both in the subgroup with unilateral and, even more so, in those with bilateral renal artery lesions. The best trade-off between sensitivity and false-positive rate was provided by cut-off values of 1.55 and 1.70 of the RVRR for identification of non-occluded and occluded RVH, respectively.

CONCLUSIONS

RVRR is more useful for establishing an indication for nephrectomy in patients with renal artery occlusion than for identifying those patients with renal artery stenosis who will benefit from revascularization. In patients with RVH with bilateral renal artery lesions, lateralization of renin secretion occurs only in the presence of total renal artery occlusion. Different cut-off values are necessary for identification of non-occluded and occluded RVH.

Surgical management of atherosclerotic renovascular disease

OBJECTIVE

This review describes the clinical outcome of surgical intervention for atherosclerotic renovascular disease in 500 consecutive patients with hypertension.

METHODS

From January 1987 to December 1999, 626 patients underwent operative renal artery (RA) repair at our center. A subgroup of 500 patients (254 women and 246 men; mean age, 65 plus minus 9 years) with hypertension (mean blood pressure, 200 plus minus 35/104 plus minus 21 mm Hg) and atherosclerotic RA disease forms the basis of this report. Hypertension response was determined from preoperative and postoperative blood pressure measurements and medication requirements. Change in renal function was determined with estimated glomerular filtration rates (EGFRs) calculated from serum creatinine levels. Proportional hazards regression models were used for the examination of associations between selected preoperative parameters, blood pressure and renal function response, and eventual dialysis-dependence or death.

RESULTS

Two hundred three patients underwent unilateral RA procedures, 297 underwent bilateral RA procedures, and 205 patients underwent combined renal and aortic reconstruction. After surgery, there were 23 deaths (4.6%) in the hospital or within 30 days of surgery. Significant and independent predictors of perioperative death included advanced age (P <.0001; hazard ratio [HR], 3.23; 95% confidence interval [CI], 1.85 to 5.70) and clinical congestive heart failure (P =.013; HR, 3.05; 95% CI, 1.26 to 7.34). Among the patients who survived surgery, hypertension was considered cured in 12%, improved in 73%, and unchanged in 15%. For the entire group, renal function increased significantly after operation (preoperative versus postoperative mean EGFR, 41.1 plus minus 23.9 versus 48.2 plus minus 25.5 mL/min/m(2); P <.0001). For individual patients, with a 20% or more change in EGFR considered significant, 43% had improved renal function (including 28 patients who were removed from dialysis-dependence), 47% had unchanged function, and 10% had worsened function. Preoperative renal insufficiency (P <.001; HR, 2.35; 95% CI, 1.86 to 2.98), diabetes mellitus (P =.007; HR, 2.14; 95% CI, 1.15 to 3.97), prior stroke (P =.042; HR, 1.50; 95% CI, 1.02 to 2.22), and severe aortic occlusive disease (P =.003; HR, 1.69; 95% CI, 1.19 to 2.31) showed significant and independent associations with death or dialysis during the follow-up examination period. After operation, blood pressure cured (P =.014; HR, 0.52; 95% CI, 0.30 to 0.88) and improved renal function (P =.011; HR, 0.40; 95% CI, 0.19 to 0.81) showed significant and independent associations with improved dialysis-free survival rate. All categories of function response and time to death or dialysis showed significant interactions with preoperative EGFR.

CONCLUSION

The surgical correction of atherosclerotic renovascular disease resulted in blood pressure benefit and retrieval of renal function in selected patients with hypertension. The patients with cured hypertension or improved EGFR after operation showed increased dialysis-free survival as compared with other patients who underwent surgery.

Management of ischemic nephropathy: dialysis-free survival after surgical repair

PURPOSE

This retrospective review describes the surgical management of consecutive patients with severe hypertension and ischemic nephropathy due to atherosclerotic renovascular disease.

METHODS

From January 1987 through December 1998, a total of 590 patients underwent operative renal artery repair at our center. A subgroup of 232 hypertensive patients (97 women, 135 men; mean age, 66 +/- 8 years) with atherosclerotic renovascular disease and preoperative serum creatinine levels of 1.8 mg/dL or more forms the basis of this report. Change in renal function was determined from glomerular filtration rates estimated from preoperative and postoperative serum creatinine. The influence of selected preoperative parameters and renal function response on time to dialysis and dialysis-free survival was determined by a proportional hazards regression model.

RESULTS

In all, 83 patients underwent unilateral renal artery repair and 149 patients underwent bilateral repair, including repair to a solitary kidney in 17 cases. A total of 332 renal arteries were reconstructed, and 32 nephrectomies were performed in these patients. After surgery, there were 17 deaths (7.3%) in the hospital or within 30 days of surgery. Advanced patient age (P =.001; hazard ratio, 1.1; 95% CI [1.1, 1.2]) and congestive heart failure (P =.04; hazard ratio, 2.9 CI [1.0, 8.6]) demonstrated significant and independent associations with perioperative mortality. With a change of 20% or more in EGFR being considered significant, 58% of patients had improved renal function, including 27 patients removed from dialysis dependence; function was unchanged in 35% and worsened in 7%. Follow-up death from all causes or progression to dialysis dependence demonstrated a significant and independent association with early renal function response. Both patients whose function was unchanged (P =.005; hazard ratio, 6.0; CI [2.2, 16.6]) and patients whose function was worsened (P =.03; hazard ratio, 2.2; CI [1.1, 4. 5]) remained at increased risk of death or dialysis dependence. For patients with unchanged renal function after operation, risk of death or dialysis demonstrated a significant interaction with preoperative renal function. In addition to severe preoperative renal dysfunction, diabetes mellitus demonstrated a significant and independent association with follow-up death or dialysis.

CONCLUSION

Surgical correction of atherosclerotic renovascular disease can retrieve excretory renal function in selected hypertensive patients with ischemic nephropathy. Patients with improved renal function had a significant and independent increase in dialysis-free survival in comparison with patients whose function was unchanged and patients whose function was worsened after operation. These results add further evidence in support of a prospective, randomized trial designed to define the value of renal artery intervention in patients with ischemic nephropathy.

Surgery after failed percutaneous renal artery angioplasty

PURPOSE

This retrospective review describes the surgical management of 51 patients after failed percutaneous renal artery angioplasty (F-PTRA).

METHODS

From January 1987 through June 1998, 51 consecutive patients underwent surgical repair of either atherosclerotic (32 patients) or fibromuscular dysplastic (FMD; 19 patients) renovascular vascular disease after F-PTRA. These patients form the basis of this report. Surgical repair was performed for hypertension (29 patients with atherosclerosis: mean blood pressure, 205 +/- 34/110 +/- 23 mm Hg; 18 patients with FMD: mean blood pressure, 194 +/- 24/118 +/- 18 mm Hg) or ischemic nephropathy (20 patients with atherosclerosis: mean serum creatinine level, 2.0 +/- 0.8 mg/dL; three patients with FMD: mean serum creatinine level, 2.0 +/- 1.1 mg/dL). Emergency operation was required in four patients for acute renal artery thrombosis (one patient with atherosclerosis, one patient with FMD), renal artery rupture (one patient with atherosclerosis), or infected pseudoaneurysm (one patient with atherosclerosis). Operative management, blood pressure and renal function response to operation, and dialysis-free survival rate were examined and compared with 487 patients (441 patients with atherosclerosis, 46 patients with FMD) treated by operation alone.

RESULTS

Among the patients with atherosclerotic renovascular disease, there were three postoperative deaths (9.4%) after repair for F-PTRA. Secondary operative repair was associated with emergent repair or nephrectomy in 16% of cases, while more extensive renal artery exposure and more complex operative management was required in 50% of patients with atherosclerosis and 65% of patients with FMD repaired electively. Among the 28 operative survivors with hypertension and atherosclerotic renovascular disease, blood pressure benefit after F-PTRA was significantly lower when compared with patients with atherosclerosis who underwent treatment with operation only (57% vs 89%; P <.001). However, blood pressure benefit in the 19 patients with FMD did not differ (89% vs 96%). Among the 28 patients with atherosclerosis, preoperative estimated glomerular filtration rate (EGFR) as compared with postoperative EGFR was significantly increased (47.4 +/- 4.2 mL/min/1.73m(2) vs 56. 6 +/- 5.1 mL/min/1.73m(2); P =.002). However, EGFR prior to PTRA was not significantly different from postoperative EGFR (51.6 +/- 3.4 mL/min/1.73m(2) vs 56.6 +/- 4.9 mL/min/1.73m(2); P =.121). As compared with patients with atherosclerosis who underwent treatment with operation alone, there was no difference in the dialysis-free survival rate.

CONCLUSION

Operative repair after F-PTRA was altered in 59% of the patients with atherosclerosis and in 68% of patients with FMD. Blood pressure benefit for patients with FMD was unchanged after F-PTRA. However, the blood pressure benefit was significantly decreased among patients with atherosclerosis. Decreased EGFR after F-PTRA was recovered with operative renal artery repair. However, postoperative EGFR as compared with EGFR prior to PTRA was unchanged. Blood pressure and renal function response after F-PTRA for atherosclerotic renovascular disease warrants further study.