Renal artery stenting may not be appropriate for patients with atherosclerotic renal artery stenosis.

INTRODUCTION: This study compared aortorenal bypass to renal artery stenting to determine the most efficacious and financially sound method for treating patients with atherosclerotic renal artery stenosis (RAS). METHODS: A decision analysis using direct and indirect costs, and value of statistical life (VSL) was completed. Direct costs were obtained using the Nationwide Inpatient Sample (NIS), indirect costs from the National Institute of Diabetes and Digestive and Kidney Diseases, and VSL from the Department of Transportation. A variance-based sensitivity analysis was completed to assess the accuracy of the decision analysis. RESULTS: Aortorenal bypass has a 95% five-year patency, a 98% 30-day survival, a 26% rate of overall complications, and a 70% five-year dialysis-free survival. Renal artery stenting has a 56% five-year patency, a 99% 30-day survival, a 40% rate of complications, and a 65% five-year dialysis-free survival. Renal artery stenting has an overall cost of $305,370 and aortorenal bypass has an overall cost of $103,453 per patient. After accounting for VSL, renal artery stenting has a negative value of -$182,270 and aortorenal bypass has a value of $415,881. CONCLUSIONS: Lower five-year patency and higher rate of complications from renal artery stenting that ultimately lead to significantly lower five-year dialysis-free survival.

Renal artery stenosis: cost-effectiveness of diagnosis and treatment.

PURPOSE: To use a decision analytic model to determine the cost-effectiveness of performing diagnostic digital subtraction angiography (DSA), computed tomographic (CT) angiography, or magnetic resonance (MR) angiography or proceeding immediately to tentative percutaneous revascularization in patients suspected of having renovascular hypertension. MATERIALS AND METHODS: With use of a Markov-Monte Carlo decision model, cost-effectiveness analysis was performed from a societal perspective. Data were derived from the Renal Artery Diagnostic Imaging Study in Hypertension and from published literature. The base-case analyses were used to evaluate a 50-year-old patient with a diastolic blood pressure higher than 95 mm Hg and one or more clinical clues suggestive of renovascular hypertension. Outcome measures were quality-adjusted life-year (QALY), lifetime costs, and incremental cost-effectiveness. RESULTS: For a 50-year-old male patient, immediate tentative revascularization was the least costly (euro54 415) and most effective (12.265 QALYs) strategy. For the other strategies, costs and QALYs, respectively, were euro55 570 and 12.195 for DSA, euro55 191 and 12.163 for CT angiography, and euro56 890 and 12.088 for MR angiography. For a 50-year-old female patient, costs and QALYs, respectively, were euro66 731 and 13.731 for MR angiography, euro63 970 and 13.749 for CT angiography, and euro63 079 and 13.902 for DSA. Immediate tentative revascularization yielded more QALYs (13.937) and was more costly (euro63 329) than DSA. The incremental cost-effectiveness ratio was euro7143 per QALY. As the prior probability increased, use of a more invasive diagnostic imaging strategy became justified. Also, the sensitivities of CT angiography and MR angiography and the costs of DSA influenced the results. CONCLUSION: Given currently accepted incremental cost-effectiveness ratios, immediate tentative percutaneous revascularization is a cost-effective strategy for the diagnosis of renal artery stenosis. Management decisions should be conditional on the prior probability.

Cost analysis of procedures related to the management of renal artery stenosis from various perspectives.

To determine the costs associated with the diagnostic work-up and percutaneous revascularization of renal artery stenosis from various perspectives. A prospective multicenter comparative study was conducted between 1998 and 2001. A total of 402 hypertensive patients with suspected renal artery stenosis were included. Costs were assessed of computed tomography angiography (CTA), magnetic resonance angiography (MRA), digital subtraction angiography (DSA), and percutaneous revascularization. From the societal perspective, DSA was the most costly (euro 1,721) and CTA the least costly diagnostic technique (euro 424). CTA was the least costly imaging procedure irrespective of the perspective used. The societal costs associated with percutaneous renal artery revascularization ranged from euro 2,680 to euro 6,172. Overall the radiology department incurred the largest proportion of the total societal costs. For the management of renal artery stenosis, performing the analysis from different perspectives leads to the same conclusion concerning the least costly diagnostic imaging and revascularization procedure.

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.

Outcome and cost comparison of percutaneous transluminal renal angioplasty, renal arterial stent placement, and renal arterial bypass grafting.

PURPOSE: To compare the outcomes and costs of percutaneous transluminal renal angioplasty (PTRA), percutaneous transluminal stent placement (PTSP) of renal arteries, and renal arterial bypass grafting (RABG) in treatment of renovascular hypertension. MATERIALS AND METHODS: Medical records and angiograms of 130 patients who underwent PTRA, PTSP, or RABG were retrospectively studied to determine success and complication rates, angiographic stenoses, blood pressures, antihypertensive medications, and serum creatinine levels. Actual costs were analyzed in detail. RESULTS: Technical success rates for PTRA, PTSP, and RABG were 91%, 98%, and 92%, respectively. Complication rates were 13%, 16%, and 38%, respectively. The mean arterial pressure was initially lowered by 29.2 mm Hg, 30.3 mm Hg, and 27.3 mm Hg, respectively, and maintained at 21.0 mm Hg, 19.8 mm Hg, and 20.2 mm Hg below baseline at 12 months. The number of antihypertensive medications was initially reduced on average by 0.63, 0.72, and 0.58, respectively, but returned to baseline in all patients by 12 months. The serum creatinine level did not change substantially with any treatment. Initial treatment costs were $1,402, $2,573, and $15,393, respectively. CONCLUSION: PTRA, PTSP, and RABG were equally efficacious for control of renovascular hypertension. The initial treatment cost for bypass grafting was substantially higher than that for PTRA and PTSP of renal arteries.

The cost-effectiveness of the diagnosis of renal artery stenosis.

The objective of this study was to assess the cost effectiveness of eight strategies to diagnose renovascular hypertension (RVHT) followed by treatment with percutaneous transluminal angioplasty (PTRA) with or without stent placement. The eight diagnostic strategies were compared with a reference strategy, i.e. antihypertensive medication. The diagnostic imaging techniques under consideration were captopril renography, spiral computed tomography angiography (CTA), magnetic resonance angiography (MRA) and conventional angiography. Cost-effectiveness analysis was carried out from the perspective of the health care system, based on data from the literature. A model was developed to predict the reduction in 10-year morbidity and 10-year mortality owing to myocardial infarction, stroke and chronic renal failure achieved after PTRA compared with the reference strategy. Life-years gained over a 10-year follow-up period and the incremental cost-effectiveness ratio per life-year saved were the outcome measures. The strategy CTA followed by angiography was more effective, but more costly, than captopril renography followed by angiography, with an incremental cost-effectiveness ratio per life-year gained of Dfl 64700. Combining captopril renography with CTA was even more effective, but the incremental cost-effectiveness ratio per life-year gained was Dfl 236400. Strategies including MRA were not cost-effective. The results suggest that diagnostic strategies that include CTA are more effective than captopril renography in detecting renal artery stenosis (> 50%) and cost saving due to prevented myocardial infarction, stroke or chronic renal failure. MRA is even more effective, but in order to achieve an acceptable cost-effectiveness ratio, the costs would need to be reduced. The cost-effectiveness of the diagnostic strategies is sensitive to the pre-test probability of RVHT. So, careful clinical evaluation, in order to achieve a pre-test probability of at least 20%, is an essential component of the complete workup strategy in patients suspected to have RVHT.

Clinical outcome and health care costs in renal revascularization--percutaneous transluminal renal angioplasty versus reconstructive surgery.

Clinical outcome and health care costs related to investigation, treatment with either percutaneous transluminal renal angioplasty (PTRA) or reconstructive surgery, and follow-up of patients with renovascular hypertension with or without uraemia were analysed in 21 PTRA-treated and 16 operated patients. Most renal artery stenoses were atherosclerotic. Nineteen PTRAs were successful or partly successful and two failed; the patients were operated on without delay. All surgical reconstructions were successful. In the PTRA group six restenoses occurred after 4-24 months. Four were treated with re-PTRA and two were operated on. No recurrence occurred in the operated group. At the end of follow-up (median 48, range 9-84 months) primary patency in the PTRA group was 69 per cent and in the operated group 100 per cent. Secondary patency in the PTRA group was 100 per cent. With regard to hypertension, including primary and secondary results, 19 out of 21 (90 per cent) patients were improved in the PTRA group and 13 out of 16 (81 per cent) in the operated group. The diagnostic and preprocedure costs were the same in both groups, whereas the procedure and postprocedure costs were lower in the PTRA group. However, the follow-up costs were considerably higher because of recurrences and their treatment in the PTRA group. The total median cost of reconstructive surgery was 12 per cent higher than for PTRA, a non-significant difference.

Cost effectiveness in the detection of renal artery stenosis.

Cost effectivenesses of four tests for diagnosing renal artery stenosis were examined. Sensitivity, specificity, cost per patient, and cost per stenosis found for a variety of diagnostic strategies using these tests were retrospectively evaluated using clinical data from 605 hypertensive patients. Cost effectiveness of a given strategy was found to depend on the sequence in which the tests were performed, but to be relatively independent of the exact cost of the tests. Auscultation for a systolic/diastolic abdominal bruit was the most cost-effective test for beginning a diagnostic strategy and showed a 99.6% specificity for stenosis. When the patient has a systolic bruit only or no bruit, plasma renin activity measurement should guide the clinician's choice of whether to test further with intravenous pyelography or renal arteriography. Diagnosis of renal artery stenosis using these tests is estimated to cost between $2,300 and $6,200 per stenosis found, depending on the prevalence of renal artery stenosis.

The potential impact of digital video subtraction angiography on screening for renovascular hypertension.

The success of digital video subtraction angiography (DVSA) in screening hypertensive patients for renal artery stenosis and the apparent value of percutaneous transluminal angioplasty (PTA) prompted re-evaluation of the philosophy of indiscriminate medical therapy for newly discovered cases of hypertension. DVSA was diagnostic in 87% of cases. The cost of screening for renovascular hypertension by DVSA and treatment by PTA when feasible is about the same as that of medical therapy. Considering the problems of noncompliance and drug side effects associated with medical antihypertensive therapy, DVSA screening for renovascular hypertension in a broader population seems both medically and economically sound.