A comparison of duplex scanning and continuous wave Doppler in the assessment of primary and uncomplicated varicose veins

Objectives: To compare the findings of continuous wave Doppler (CWD) with duplex ultrasound in the assessment of primary and uncomplicated varicose veins, and to determine how their relative roles might be best applied. Materials and Methods: One hundred consecutive limbs were studied in 73 patients with primary (no previous surgery) and uncomplicated (no significant skin change) varicose veins. CWD was employed by a single observer; followed by duplex scanning performed "blind" and independently. Results: There were 87 limbs with long saphenous incompetence on duplex; all but four of which were correctly identified by CWD, by which technique there were no false positives. (Sensitivity 95%, specificity 100%.) There were 21 limbs with short saphenous incompetence on duplex, all but two of which were recognised on CWD. However, CWD incorrectly diagnosed reflux at the saphenopopliteal junction in five limbs (false positives) with what was, in fact, segmental reflux in the long saphenous trunk on duplex (sensitivity 90%, specificity 93%.) This would have led to inappropriate exploration of the saphenopopliteal junction had surgery proceeded without checking with duplex. Conclusions: CWD is adequate for long saphenous incompetence. All "reflux" demonstrated an CWD in the popliteal fossa (about 25% of cases) should be checked by duplex. If this policy had been followed, all the patients in this study would have undergone the correct procedure. The only "errors" would have been missing coexistent short saphenous incompetence in two limbs undergoing appropriate long saphenous exploration.