Ultrasound evaluation of the anatomy and hemodynamics of the Giacomini vein.

BACKGROUND: Ultrasound characteristics of the Giacomini vein (GV) in Chinese populations remain poorly defined. The aim of this study was to analyze the anatomical and hemodynamic characteristics of the GV using color Doppler ultrasound and to provide evidence to support clinical diagnosis and treatment. METHODS: Prospectively, 121 patients with lower extremity discomfort and varicose veins were continuously collected from July 2025 to January 2026, involving a total of 238 limbs. Patients were categorized into a primary group (C0) and a varicose group (C1-C4) according to the CEAP (Clinical, Etiological, Anatomical, and Pathophysiological) classification. All patients underwent ultrasound examination, and 38 cases underwent digital subtraction angiography (DSA). The GV was classified into four types. Agreement between ultrasound and DSA findings was assessed using Kappa statistics. Differences in GV detection rate, inner diameter, and reflux-related parameters were compared between groups, among GV types, and according to the severity of saphenous vein reflux. RESULTS: Ultrasound and DSA demonstrated high concordance in GV classification (kappa =0.854). The overall GV detection rate was 73.95%, with a significantly higher rate in the right lower limb than in the left lower limb (P<0.05) and no significant difference between sexes. The great saphenous vein (GSV) confluence type was the most prevalent (73.3%). Detection rates of GV presence and reflux were significantly higher in the varicose group than in the primary group (P<0.05), whereas no significant difference in inner diameter was observed. Reflux detection rates showed an increasing trend across varicose subgroups; however, this trend did not reach statistical significance. The incidence of GV reflux was significantly higher in the small saphenous vein (SSV) reflux group and in the group with both GSV and SSV reflux than in the GSV reflux group (P<0.05). The severity of saphenous vein reflux had no significant effect on GV-related parameters. CONCLUSIONS: Ultrasound demonstrated significant clinical utility in the assessment of the GV. GV reflux was closely associated with the severity of lower extremity varicose veins and with the type of saphenous vein reflux. Prioritization of preoperative GV assessment may reduce postoperative recurrence rates and minimize intraoperative injury.