Reflux origin of the insufficient small saphenous vein by duplex ultrasound determination and consequences for therapy considering the saphenopopliteal junction type.

OBJECTIVE: The reflux pathophysiology of the saphenofemoral junction (SFJ) of the insufficient great saphenous vein (GSV) has already been investigated and stratified. These results are still lacking for the small saphenous vein (SSV). The aim of the study was to analyze the pathophysiology of the saphenopopliteal junction (SPJ) in case of refluxing SSV. METHODS: The study included 1142 legs investigated between April 1, 2019, and February 15, 2023, with chronic venous insufficiency scheduled for endoluminal thermal ablation of the insufficient SSV. Preoperatively, a standardized duplex ultrasound assessment of the SPJ including the cranial extension of the SSV and the Giacomini vein, respectively, was performed to determine the origin of reflux. Having in mind, that the draining type according to Cavezzi is relevant to the treatment planning, after having scanned 152 legs, the protocol was extended to this feature: Cavezzi type A1 or A2 was recorded on 990 legs. RESULTS: In 984 cases (86%), saphenopopliteal reflux from the popliteal vein into the insufficient SSV was detected, and in 181 cases of these (16%), simultaneous refluxing blood from the cranial extension or Giacomini vein was found. In 119 cases (10%), reflux resulted only from the cranial extension or Giacomini vein with a competent SPJ, and in 39 cases (3%), the reflux source was diffusely from side branches and/or perforating veins. Cavezzi's junction types A1 (independent junction of SSV and muscle veins) and A2 (muscle veins join into SSV, draining together into the popliteal vein through the SPJ) were found in 65% and 35% of cases, respectively. CONCLUSIONS: The insufficient SSV shows a high frequency of axial reflux from the deep into the saphenous vein with an indication for high ligation or thermal ablation at the level of the SPJ or immediately distal to the inflow of muscular veins depending on the junction type. In 14%, based on this study, we observed a competent junction of the SSV without indication for ligation or thermal destruction of the SPJ.