Evaluation of Varicose Veins of the Lower Extremity: the Value of the Duplex Ultrasound (Part 1)

Safety and efficacy of endovenous thermal ablation for treatment of symptomatic varicose veins during summertime

Background: Traditionally, varicose vein treatment is predominately performed during the colder seasons. However, data whether higher outdoor temperatures affect the outcome and/or complication rate of endovenous thermal ablation (ETA) for treatment of symptomatic varicose veins are missing. Patients and methods: In this observational study, the medical records of all patients who had ETA of the great saphenous vein (GSV), accessory saphenous vein (ASV), or small saphenous vein (SSV) between September 2017 and October 2020 were reviewed. Results: In total 846 ETA interventions in 679 patients with 1239 treated truncal veins and an average length of 69 cm phlebectomy were included. The highest temperature recorded on and within the first 14 days after treatment was on average 19.0°C (SD±7.2°C) with a minimum and maximum of -1°C and 35.9°C. Interventions were categorized according to the recorded temperature (<25°C n=584; 25-29.9°C n=191; and ≥30°C n=71). The occlusion rates were excellent (99-100%) across groups. Despite a significantly higher proportion of patients with obesity, personal history of superficial vein thrombosis and length of phlebectomies in the high temperature groups, no significant difference regarding days of work loss, patients' satisfaction or complications including bleeding or thromboembolic events was observed. Infections were rare (0.8%), but more frequently observed in the 25-29.9°C group (2.6%; p=0.058). No infection was observed in the ≥30°C group and pain 6 weeks after the intervention was even lower (VAS 0.5±1.0 and 0.5±1.2 vs. 0.0±0.1, p=0.008). Conclusions: Given the minimal invasive nature of ETA, our results can reassure clinicians and patients that ETA varicose vein treatment is possible and safe throughout the year, even on hot summer days. A non-significant trend to more infections was observed but was not associated with other adverse outcomes such as prolonged analgetics intake or inability to work.

Evaluation of Peak Reflux Velocities with Vector Flow Imaging and Spectral Doppler Ultrasound in Varicose Veins

Purpose Spectral Doppler ultrasound (SDUS) is used for quantifying reflux in lower extremity varicose veins. The technique is angle-dependent opposed to the new angle-independent Vector Flow Imaging (VFI) method. The aim of this study was to compare peak reflux velocities obtained with VFI and SDUS in patients with chronic venous disease, i. e., pathological retrograde blood flow caused by incompetent venous valves. Materials and Methods 64 patients with chronic venous disease were scanned with VFI and SDUS in the great or the small saphenous vein, and reflux velocities were compared to three assessment tools for chronic venous disease. A flow rig was used to assess the accuracy and precision of the two methods. Results The mean peak reflux velocities differed significantly (VFI: 47.4 cm/s vs. SDUS: 62.0 cm/s, p<0.001). No difference in absolute precision (p=0.18) nor relative precision (p=0.79) was found. No correlation to disease severity, according to assessment tools, was found for peak reflux velocities obtained with either method. In vitro, VFI was more accurate but equally precise when compared to SDUS. Conclusion Both VFI and SDUS detected the pathologic retrograde flow in varicose veins but measured different reflux velocities with equal precision. VFI may play a role in evaluating venous disease in the future.

Vector and Doppler Ultrasound Velocities Evaluated in a Flow Phantom and the Femoropopliteal Vein

Ultrasound is used for evaluating the veins of the lower extremities. Operator and angle dependency limit spectral Doppler ultrasound (SDUS). The aim of the study was to compare peak velocity measurements in a flow phantom and the femoropopliteal vein of 20 volunteers with the angle-independent vector velocity technique vector flow imaging (VFI) and SDUS. In the flow phantom, VFI underestimated velocity (p = 0.01), with a lower accuracy of 5.5% (p = 0.01) and with no difference in precision, that is, error factor, compared with SDUS (VFI: 1.02 vs. SDUS: 1.02, p = 0.58). In vivo, VFI estimated lower velocities (femoral: p = 0.001; popliteal: p = 0.001) with no difference in precision compared with SDUS (femoral: VFI 1.09 vs. SDUS 1.14, p = 0.37; popliteal: VFI 1.13 vs. SDUS 1.06, p = 0.09). In conclusion, the precise VFI technique can be used to characterize venous hemodynamics of the lower extremities despite its underestimation of velocities.