D. Eugene Strandness, Jr., MD, vascular surgeon of persistent curiosity.

As a junior colleague of Dr. D. E. Strandness, Jr., for almost 30 years, I had the unique professional opportunity to witness the development of duplex ultrasonography at the University of Washington. "Gene" as he liked to be called, was a surgeon with a persistent curiosity about vascular disease. He led the multidisciplinary team that developed the technique of duplex ultrasound, measured its diagnostic accuracy, and performed research studies to reduce stroke due to carotid bifurcation atherosclerosis. My reflections on the legacy of Dr. Strandness are offered with gratitude for the curiosity "bug" he nurtured in me, which continues today.

Carotid duplex criteria: What have we learned in 40 years?

Before the development of the first prototype duplex ultrasound scanner at the University of Washington in the late 1970s, the only noninvasive tests available for extracranial carotid artery disease were indirect methods, such as the periorbital Doppler examination and oculoplethysmography. The duplex scanner combined real-time two-dimensional B-mode imaging and pulsed-Doppler flow detection in a single instrument and provided Doppler spectral waveforms from discrete sites within the vessel lumen. Spectral waveforms allowed characterization of the flow patterns and velocity changes associated with normal and diseased arteries. In a series of validation studies, Dr. D. Eugene Strandness, Jr. and colleagues compared various spectral waveform parameters obtained from internal carotid arteries to independently read carotid arteriograms and established quantitative threshold criteria for classification of carotid artery disease. These criteria were based on peak systolic velocity and end-diastolic velocity, as well as features such as spectral broadening and flow separation. Internal carotid arteries were classified as normal, 1% to 15% diameter reduction, 16% to 49% diameter reduction, 50% to 79% diameter reduction, 80% to 99% diameter reduction, and occluded. Since the 1980s, the University of Washington carotid duplex criteria have been widely used and modified in vascular laboratories throughout the world. Additional clinically relevant criteria have also been developed, such as a threshold for the 70% to 99% North American Symptomatic Carotid Endarterectomy Trial (NASCET) stenosis. Validation of carotid criteria has always depended on comparing spectral waveform parameters to the "gold standard" of contrast arteriography. However, experience has shown that the relationship between velocity and arteriographic stenosis is subject to significant variability. Based on these observations, standardization of carotid duplex criteria should lead to more consistent reporting among vascular laboratories, but it is unlikely to result in improved correlation with arteriography.

Historical overview of varicose vein surgery.

Varicose veins are as old as Hippocrates. Varicose vein treatments come and go. Surgery for varicose vein disease is one of the commonest elective general surgical procedures. The history of varicose vein surgery has been traced. We note the first descriptions of varicose veins, and we particularly focus on the ligation of the saphenofemoral junction, stripping of the great saphenous veins, phlebectomy, and perforant vein surgery. We end with the rapid rise of minimally invasive procedures, such as foam sclerotherapy, radiofrequency ablation, and endovenous lasertherapy. Within 10 years, the advantages of minimal invasiveness for these procedures, combined with claims of equivalent short-term outcomes and even better long-term results, have already influenced our everyday practice. At present, the gold standard treatment of varicose veins still is surgical ligation and stripping of the insufficient vein. Concomitantly or sequentially with the treatment of truncal insufficiency, residual varicosities can be treated by phlebectomy. New minimally invasive techniques, however, have changed the clinical landscape for varicose vein surgery tremendously. The dramatic changes of the last decade are probably the precursors of the next generation.

History of ultrasonic duplex scanning.

Ultrasonic duplex scanning was developed and introduced into clinical practice by the combined efforts of engineers and physicians. The instrumentation represents a marriage of B-mode imaging and Doppler technology. Since its introduction in 1974, numerous modifications and upgrading of the technology have taken place. The modern duplex scanner can be used to study vascular disease wherever it is found in the body.