Abstract
To the Editor:
We read with interest the article by DeMuth et al. Our purpose is not to criticize it but to take the opportunity to discuss a subject that has been debated for a long time in the field of vascular sonography. Although we agree with some of the findings, we do not want the readers of this journal to deviate from the main purpose of the venous reflux examination. Therefore, we are going to make a few suggestions and constructive comments.
The main purpose of a venous ultrasound study in patients presenting with signs and symptoms of chronic venous disease (CVD) is not to evaluate the great saphenous vein (GSV) but to evaluate the entire extremity. This should include the GSV, the small saphenous vein (SSV), their tributaries, the nonsaphenous veins, perforating veins, and the deep vein system.
Furthermore, the supine position, even with a modest reversed Trendelenburg (15–25°), will not allow precise examination of the extremity. We would like to believe that vascular technologists aspire to perform a vascular examination in the best possible manner to provide the greatest benefit to the patient. We also believe that we should not be debating if the venous reflux examination should be performed in the reversed Trendelenburg or standing position, but coaching the vascular technologist on factors that affect results, temporal or otherwise, to perform an accurate and complete examination.
Clearly, it may not be necessary to scan every single vein when you perform a venous reflux examination; common sense and experience should prevail to tailor it to the patients' clinical presentation. Examination of the GSV alone, although it has the greatest prevalence of reflux, is far from being sufficient to allow correct planning when treating patients with CVD.
This study addresses a key point, the lack of understanding that the venous system is extremely complex, and that there are many factors aside from patient positioning that impact the results of CVD studies. Therefore, those performing duplex ultrasound to examine patients with CVD would be helped by understanding factors that could produce false results and where to look beyond the GSV to understand more fully a patient's true pathology.
In this small study, the authors indicated that position “changed the clinical outcome in only one subject in this series.” There were both false-positive and false-negative findings in the reversed Trendelenburg position, like in our study. 1 It is worth mentioning that in our study we examined both patients and controls in multiple locations and had a standard stimulus to elicit reflux providing more robust data. The false-negative and false-positive findings should be emphasized. This is one more reason to be cautious when the reversed Trendelenburg is used alone.
Interpretation of the current study could potentially lead the reader to minimize positional effects in a larger sense. In our experience, the phenomenon of positional variation is greater for patients in CEAP class C2, as opposed to CEAP classes C4, 5, and 6. However, patients with CEAP classes 4 to 6 have more often reflux in the deep veins compared with those in 1 to 3.2,3 Furthermore, at least one quarter of patients with skin damage (CEAP classes 4–6) have also had a previous deep vein thrombosis.2,3 Reflux affecting veins at three levels, superficial, perforator, and deep, is mostly found in patients with skin damage.3,4 Therefore, a more detailed examination in the deep veins should be done. At least one quarter of patients present with some degree of skin damage among patients with CVD.3,4 Nonsaphenous vein reflux is found in at least 1 in 10 patients with CVD, which doubles in patients with recurrent varicose veins.5–7 More importantly all the aforementioned veins have their largest diameter in the standing position and are easier to see. Also, in this position, many veins become apparent, and it is easier to trace the pattern of reflux and make the examination faster and accurate. For example, veins of pelvic origin that communicate with the lower-extremity veins, the vein of the popliteal fossa, the thigh extension of the SSV, and the sciatic nerve veins are best seen in the standing position.5,8–10 The hydrostatic pressure is at the highest level and therefore the valvular function is challenged in a more physiologic manner.
Finally, the authors erroneously referred to the small saphenous vein (i.e., SSV) as the “lesser saphenous” vein, not promoting the use of current nomenclature.11,12