The report is a product of the VA/HSR Evidence Synthesis Program.

Cost-Effectiveness of Leg Bypass versus Endovascular Therapy for Critical Limb Ischemia

Critical limb ischemia (CLI) is a severe form of peripheral arterial disease marked by ischemic rest pain, tissue loss, or gangrene. CLI is associated with significant morbidity, mortality, and resource utilization. Diagnostic evaluation and revascularization are important steps in the management of patients with CLI, with revascularization taking two primary forms – surgery or endovascular therapy. While the efficacy of surgical versus endovascular therapy for CLI continues to be debated, the economics are also unclear.

The aim of this rapid review was to help clinicians, patients, and policymakers decide between surgery-first and endovascular-first approaches for patients with CLI. Investigators with VA's Evidence Synthesis Program in West Los Angeles, CA reviewed the literature in PubMed from 1/1/2000 to 1/16/2019 and Embase from 1/1/2000 to 1/17/2019. After conducting a full-text review of 143 publications, investigators identified 27 articles that were useful for this review, which included 5 reports from the BASIL RCT to which they added 4 cost-effectiveness models and 18 observational studies.

Summary of Findings

Cost-effectiveness
The cost-effectiveness of surgery compared to an endovascular approach is not known and won't be known until ongoing trials report their results. The only randomized trial of this comparison resulted in an incremental cost-effectiveness ratio for surgery at or above the thresholds normally used to categorize an intervention as cost-effective, but the report is too dated in terms of the endovascular intervention (limited to balloon angioplasty) and general improvements in care (e.g., length of stay) to be used as a basis for a conclusion about contemporary CLI care.

More recent cost-effectiveness models have found a lower incremental cost-effectiveness ratio, yet these results can only be as sound as their underlying data, for which no randomized comparisons of modern therapies have been published.

Observational studies of effectiveness and utilization have found, in general, that endovascular therapy is associated with shorter initial hospital lengths of stay and similar (or even better) short-term outcomes (e.g., 30-day mortality) than surgery; however, there are signals that longer-term outcomes like mortality and patency may favor surgical therapy. However, baseline differences between patients may be as – or more responsible for long-term differences in mortality than initial choice of endovascular or surgical therapy.

Hospital length of stay
The certainty of evidence is high that endovascular therapy has a lower initial hospital length-of-stay compared to surgical therapy. One RCT found shorter LOS for patients treated endovascularly, and it is a consistent finding in observational studies. This finding also is compatible with what is known about the need for in-hospital care for the two treatments, and that in cardiovascular disease these differences between surgery and percutaneous coronary interventions in length-of-stay also exist.

Mortality
The certainty of evidence is low that endovascular therapy has lower short-term mortality than surgical therapy. The one RCT is too dated to be of much value, with respect to mortality as an outcome, and the observational studies are consistent but at high risk of bias.

The certainty of evidence is very low that surgical therapy has lower long-term mortality than endovascular therapy. There is a signal in the observational studies, and there is a statistically significant benefit in the one RCT, but these are subject to the same reservations about the RCT.

Cost-effectiveness by population
There is insufficient evidence to assess whether surgery versus endovascular therapy may be preferred in certain populations or settings. Evidence for the outcome of cost-effectiveness varying in certain populations also was very low, with one exception: investigators judge the certainty of evidence is low that endovascular therapy will be less cost-effective than surgery in infrapopliteal disease, based on the evidence from the one RCT suggesting possibly worse outcomes for endovascular therapy in such patients.

VA studies
Investigators identified two studies that were specifically about VA settings and VA care, but these (by the same first author) likely have overlapping patient populations. The earlier study assessed 275 patients treated between June 2001 and June 2005, and the later study assessed 433 patients between December 2002 and September 2010. For survival, the authors noted similar results to the BASIL trial. They found an initial, non-significant difference favoring endovascular treatment (3% vs 6%), but after one year or so, a trend favoring surgical therapy (proportion alive at 24 months, 66% vs 60%). Length of stay was shorter for patients treated endovascularly (4.8 vs 9.7 days). Long-term primary patency rates favored surgical patients (5-year primary patency rates of 66% vs 39%), while long-term limb salvage rates did not differ between groups.

Future Research
The biggest research gap is high-quality evidence of the differences in outcomes between CLI patients treated with surgery or an endovascular approach. This gap has been recognized for some time now, and there are several trials underway. Recently the investigators for BEST-CLI modified its protocol to increase the sample size and extend the duration of follow-up, an indication that definitive results from this trial are not expected soon. In the meantime, if the VA Surgical Quality Improvement Program (VASQIP) – a comprehensive all-specialty surgical database – has a sufficient number of cases, an analysis of the rich data in this prospective observational database would be informative.

Register for the "Cost-Effectiveness of Leg Byass versus Endovascular Therapy for Critical Limb Ischemia" cyberseminar to be held on Monday July 1, 2019 from 3:00pm to 4:00pm EST..

Reference
Childers C, Lamaina M, Liu C, Mak S, Booth M, Gibbons M, Shekelle PG. Cost-effectiveness of Leg Bypass versus Endovascular Therapy for Critical Limb Ischemia. Washington, DC: Evidence Synthesis Program, Health Services Research and Development Service, Office of Research and Development, Department of Veterans Affairs.VA ESP Project#05-226; 2019.

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• Diabetes
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• Hypertension
• Stroke

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