An Evaluation of Doppler Ultrasound and Photoplethysmography in the Investigation of Venous Insufficiency

Abstract

Non‐invasive methods of venous assessment have been developed to improve diagnostic accuracy in the assessment of venous insufficiency. Of these, continuous wave Doppler (CWD) ultrasound and photoplethysmography are the cheapest and most simple to perform. In this study duplex scanning was used to test the accuracy of these two methods. One hundred and thirty‐six patients attending the venous outpatient clinic at Middlesex Hospital, London were examined by all three techniques and a diagnosis was reached using each technique. The technicians performing the examinations were unaware of the diagnoses reached by the other methods. Continuous wave Doppler ultrasound was found to be most accurate in the diagnosis of long saphenous incompetence (sensitivity 73%, specificity 85%). Due to the variability of venous anatomy at the popliteal fossa and the ‘blindness’ of the technique, it was inaccurate in the diagnosis of short saphenous incompetence (sensitivity 33%) and deep vein reflux (sensitivity 48%). Photoplethysmography was found to be most accurate in the diagnosis of deep vein reflux (sensitivity 79%, specificity 70%) but was inaccurate in identification of the site of superficial vein reflux. Inaccuracies may be attributed to the presence of incompetent perforating veins and variation in arterial inflow.

Venous Reflux at the Sapheno-Femoral Junction

“…It demonstrates incompetence at the saphenofemoral junction but not incompetence through the sapheno-femoral junction. The limitations of continuous-wave Doppler are well know; assumptions based on Doppler findings may be inaccurate to a certain extent, because of lack of visualization and localization [16][17][18].…”

The care of patients with varicose veins and associated chronic venous diseases: Clinical practice guidelines of the Society for Vascular Surgery and the American Venous Forum

“…It has much better diagnostic accuracy in the assessment of venous insufficiency than continuous-wave Doppler ultrasonography. 80 B-mode imaging permits accurate placement of the pulsed Doppler sample volume, and the addition of color makes it easier to establish obstruction, turbulence, and the direction of venous and arterial flow. 44 Duplex scanning is excellent for the evaluation of infrainguinal venous obstruction and valvular incompetence.…”

“…The technique of venous duplex scanning has been described in detail previously by several authors. 80,[83][84][85][86][87][88] The pulsed-wave Doppler of 4 to 7-MHz linear array tranducers are used most frequently for the deeper veins, with the higher-frequency probes used more to assess the superficial veins. Evaluation of reflux in the deep and superficial veins with duplex scanning should be performed with the patient upright, Pigmentation and/or eczema C 4b…”

Management of venous leg ulcers: Clinical practice guidelines of the Society for Vascular Surgery® and the American Venous Forum

“…Whereas continuous-wave Doppler ultrasonography can be used, comprehensive color flow venous duplex ultrasound including B-mode gray-scale imaging, pulsed Doppler sampling, and color flow analysis has improved diagnostic accuracy and reproducibility and is the preferred first-line diagnostic test for all patients with suspected VLU. [145][146][147][148] Comprehensive venous duplex ultrasound evaluates for both venous obstruction/DVT and venous reflux and includes the following components: direct visualization of deep, superficial, and perforator venous anatomic segments; compressibility; phasic venous flow with and without augmentation maneuvers; and documentation of venous reflux with measurement of valve closure time. 149,150 Venous obstruction is present when thrombosis is directly visualized, noncompressibility of vein segment is present, phasic venous flow is absent with and without augmentation maneuvers, and extensive collateral vessels are present around the segment.…”