Invited commentary

Abstract

This meticulous evaluation of the repeatability and reproducibility of venous duplex imaging by a distinguished group of investigators represents the first phase of the Investigating Venous Evaluation and Standardization of Testing (INVEST) study, the program initiated by the American Venous Forum to develop reporting standards for diagnostic venous studies. Given the extraordinarily widespread use of venous duplex imaging and its critical role in the diagnosis and treatment of chronic venous insufficiency, such standardization is vital for the clinical and research missions associated with this disease. All duplex examinations, as we know from our arterial experience, are highly operator dependant, and thus, establishment of their reliability is essential. On the arterial side, this has largely been accomplished through the application of standard methodologies to perform and report studies and validation by comparison with arteriography. The current study is the first step in such an effort for venous noninvasive diagnosis. It should be noted at the outset that this study is not designed to evaluate the accuracy of venous duplex imaging, but only its repeatability and reproducibility and the factors that can affect these end points. The key findings of this study were that the greatest repeatability was achieved when scans were performed in the morning with the individual standing, and that use of the shorter 0.5-second cut point improved agreement between interpretations of reflux (not validity). In addition, education by standardized training of technologists and the application of a single examination protocol improved reproducibility. This rigorously conducted study is a strong first step in the process of standardizing venous duplex imaging. From it we have learned that adhering to a standard protocol matters more than factors that cannot be controlled, that experience and precision matter, and that studies performed by different individuals in different laboratories on different patients can be compared in a meaningful way when standardization is applied. These important observations allow us to take the next steps in the process, which will involve formalizing performance and reporting standards and creating the expectation that they will be adhered to. Despite the accomplishments of this study in determining the repeatability and reproducibility of venous duplex imaging, there remains an important but unanswered question yet to be addressed: What is the validity of venous duplex imaging? This may prove quite challenging because we lack a gold standard, such as carotid arteriography, for comparison, but most certainly merits our further investigation. Multicenter assessment of venous reflux by duplex ultrasoundJournal of Vascular SurgeryVol. 55Issue 2PreviewThis prospective multicenter investigation was conducted to define the repeatability of duplex-based identification of venous reflux and the relative effect of key parameters on the reproducibility of the test. Full-Text PDF Open Archive