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Reporting standards of the Society for Vascular Surgery for endovascular treatment of chronic lower extremity peripheral artery disease: Executive summary

      Recommended reporting standards for lower extremity ischemia were last published by the Society for Vascular Surgery in 1997. Since that time, there has been a proliferation of endovascular therapies for the treatment of chronic peripheral arterial disease. The purpose of this document is to clarify and update these standards, specifically for reports on endovascular treatment. The document is divided into sections: Claudication Reporting, Critical Limb Ischemia Reporting, Preintervention Assessment and Nonanatomic Treatment, Intervention, Outcome Measures – Procedural, Outcome Measures – Disease Specific, and Complications.
      Peripheral arterial disease (PAD) represents a spectrum from asymptomatic stenosis to limb-threatening ischemia. The last decade has seen a tremendous increase in the variety of endovascular devices and techniques to treat occlusive disease. As for many evolving technologies, the literature surrounding endovascular arterial therapy consists of mixed-quality manuscripts without clear standardization. Accordingly, critical evaluation of the reported results may be problematic. As such, providers and their patients make treatment decisions without the full benefit of a comparative effectiveness framework.
      The purpose of this document is to provide an overview and summary for the reporting of endovascular revascularization techniques in the setting of chronic disease, with the full document being available online. Much of the work in this document is based on prior publications and standards proposed by the Society for Vascular Surgery (SVS). The authors have also made recommendations based on current literature and have attempted to acknowledge shortcomings and areas for future research. The various sections contain summaries of required reporting standards and should serve as a guide for the design of clinical trials and a reference for journal editors and reviewers when considering scientific work pertaining to endovascular therapy for chronic lower extremity arterial disease.

      Claudication reporting

      • 1.
        An ankle-brachial index (ABI) ≤0.90 is the threshold for diagnosis of PAD. As stated in the recently published SVS guidelines, when the ABI is borderline or normal (>0.9) and symptoms of claudication are suggestive, we recommend exercise ABI.
      • 2.
        Baseline functional characterization with treadmill testing or preferably ambulatory testing by 6-minute walk test.
      • 3.
        Quality of life assessment by validated scoring system, such as the Walking Impairment Questionnaire.
      • 4.
        Classification of severity based on previously published SVS guidelines.

      Critical limb ischemia reporting

      • 1.
        In patients with rest pain, an ankle pressure <40 mm Hg, ABI <0.4, or toe pressure <30 mm Hg is sufficient to substantiate the diagnosis. For patients with ulcers or gangrene, a higher ankle pressure of <70 mm Hg or toe pressure of <50 mm Hg is accepted to meet criteria.
      • 2.
        Rest pain and tissue loss patients should not be grouped together in reporting outcomes.
      • 3.
        Use of the SVS comprehensive threatened limb staging system, Wound, Ischemia, and foot Infection (WIfI), which classifies severity on the basis of three components—grading of the wound (W), presence of ischemia (I), and foot infection (fI)—to stratify tissue loss patients.

      Preinterventon assesment and nonanatomic treatment

      • 1.
        Patient comorbidity and medical therapy factors should be categorized using standard supplied definitions and severity indices.
      • 2.
        Duplex ultrasound, axial angiography, and catheter-based angiography all have a role in delineating anatomy. Clear descriptions of protocols and criteria are required if these examinations are used to include or to exclude patients from a study.
      • 3.
        Anatomy should be categorized by TransAtlantic Inter-Society Consensus (TASC II) guidelines for aortoiliac and femoropopliteal segments, and use Bollinger or SVS runoff score for infrageniculate segments.
      • 4.
        Lesions should be further categorized by length and calcification. A validated calcium grading system does not exist at this time.

      Intervention

      • 1.
        Reports should characterize anatomic location (vessel-specific reporting) and primary vs secondary intervention.
      • 2.
        Angioplasty trials should report definitive balloon diameter and length.
      • 3.
        Stent trials should document predilation and other adjuncts in addition to definitive diameter and length.
      • 4.
        Atherectomy trials should report device-specific data, such as treatment time, quantitative measures of plaque excision, and use of embolic protection device.
      • 5.
        Radiation dose, contrast volume, total treatment time, and intraprocedural pharmacology should be recorded.

      Outcome measures—procedural

      • 1.
        Technical success is defined as successful use of a device or technique to establish vessel patency with a residual stenosis <30%. Procedural success is defined as technical success and completion of the procedure without complications (see later).
      • 2.
        Hemodynamic success is defined as a pressure gradient <10 mm Hg across a lesion or corresponding increase in ABI of 0.10 or toe pressure of 0.10. Other measures of hemodynamic success (such as pulse volume recording amplitude) may be acceptable.
      • 3.
        Patency is evaluated by an accepted imaging technique of the specific arterial site treated that clearly shows flow through the lesion.
      • 4.
        Within the context of a clinical trial, duplex ultrasound should be considered the standard for patency and restenosis surveillance. A peak systolic velocity >300 cm/s or peak systolic velocity ratio >3.0 indicates restenosis.
      • 5.
        Target lesion revascularization can be driven by clinical, anatomic, and hemodynamic indications and as such does not always contribute to the assessment of clinical failure. It should not be used as a primary end point.

      Outcome measures—disease specific

      • 1.
        In addition to anatomic and hemodynamic measures of success, claudication trials should include disease-specific quality of life outcome measures and functional assessment.
      • 2.
        Critical limb ischemia trials should use the objective performance goals as measures of efficacy and safety in addition to disease-specific and overall quality of life measures.
      • 3.
        Lower extremity endovascular therapy for PAD should be reported at minimum for 30-day, 1-year, and 2-year follow-up, promoting standardization and hence more clinically meaningful comparisons of peripheral vascular interventions. Five-year follow-up is preferable.

      Complications

      • 1.
        Complications are categorized into procedural or device related, as outlined in prior SVS documents.
      • 2.
        A minimum of 30 days of complication reporting is required; subacute and late complication reporting is suggested.