GSV Anatomy: The Most Important Vein in Varicose Disease
The great saphenous vein (GSV) is the longest vein in the human body, running from the medial ankle to the groin where it joins the common femoral vein at the saphenofemoral junction (SFJ). It travels superficially along the medial aspect of the leg and thigh, separated from the deep venous system by the saphenous fascia.
GSV incompetence — valve failure causing retrograde flow — is responsible for the majority of varicose vein presentations in clinical practice. When the SFJ valve fails, increased hydrostatic pressure propagates down the GSV and into tributary veins, creating the classic pattern of medial and posterior thigh varicosities.
VenaBlock® Catheter Positioning for GSV Treatment
Access is typically obtained at the level of the knee or upper calf using ultrasound-guided puncture. The VenaBlock® catheter is advanced proximally to a position 5 cm distal to the SFJ — a critical safety margin that prevents adhesive from entering the deep venous system.
This 5-cm safety distance is smaller than what is required for thermal ablation (which needs a larger heat-free zone to protect the common femoral vein and femoral nerve), allowing VenaBlock® to treat a longer segment of the incompetent GSV.
The Treatment Zone
Adhesive delivery proceeds from the proximal treatment point (5 cm from SFJ) distally to the access site, with controlled pull-back of the catheter and simultaneous external compression. The entire incompetent GSV segment is treated in a single pass.
Outcome Data for GSV Closure
Registry data for VenaBlock® GSV treatment reports:
- 6-month GSV occlusion rate: 97.5%
- 3-year GSV occlusion rate: 93–95%
- 12-month GSV occlusion rate: 93.75% (long-term follow-up ongoing)
These results are consistent with published outcomes for both EVLA and RFA, confirming that VenaBlock® provides long-term GSV closure equivalent to thermal techniques without the associated thermal risks.
Adjunctive Treatments
Following GSV closure with VenaBlock®, residual varicose tributaries can be treated in the same session or at a subsequent visit using ultrasound-guided foam sclerotherapy or ambulatory phlebectomy, completing the comprehensive treatment of the superficial venous system.