What is a venous duplex study anyway? Redefining ultrasound protocols in modern venous practice

Introduction: Venous duplex ultrasound (VDU) is the diagnostic standard for deep venous thrombosis (DVT); however, modern venous practice requires information for a variety of other venous disorders. Protocols and standards may not have kept pace with these demands. Our aims were to (1) identify disease-specific study standards, (2) survey the community practice of VDU, and (3) consider if there is a practice gap. Methods: A web-based search was conducted to identify standards for VDU studies under the headings of DVT, superficial vein thrombosis (SVT), chronic venous insufficiency (CVI), venous reflux (VR), venous mapping, and prevenous ablation studies. Only those returns that gave specific protocol recommendations were included for analysis. Fifty VDU reports from six community facilities were analyzed using an audit tool; these were compared to a specialized “index” laboratory. Gaps were identified by comparing the recommendations to the interpretation reports. Results: The search returned approximately 50,000 citations (range 855–21,000). Recommendations from recognized authorities (Society for Vascular Ultrasound, Intersocietal Accreditation Commission Vascular Laboratory (ICAVL), College of Physicians and Surgeons of Ontario, and Radiological Society of North America) and peer-reviewed publications were used to define appropriate study protocols. Studies used a “DVT protocol” (38/50 = 76%), regardless of the indication; all studies in the index laboratory used focused protocols. For SVT, it was not related to connections to the deep system (0%); index laboratory 100%. For CVI, VR level was noted in 25%; index laboratory 100%. For patients with venous ulceration, arterial assessments were not added to the venous study. For patients with other nonvenous findings, these were not described in the studies. The comparison of findings from the community laboratories to the index laboratory confirms practice gaps in the assessment of all areas of venous disease. Venous mapping and prevenous ablation studies were only done in specialized facilities. Conclusion: A significant gap is present between community VDU practice and recommended standards and index laboratory protocols for the spectrum of venous disease. Advocacy for established standards and redefined study protocols is required for appropriate VDU practice and quality care of these patients.