Association between venous reflux and diameter of great saphenous vein in lower thigh

Venous reflux may occur in all parts of the great saphenous vein (GSV). The GSV diameter generally increases when venous reflux occurs, and the extent of venous dilation may be altered on the basis of size and location of the reflux within the GSV. We examined which part of the GSV is the most sensitive and dilated in association with venous reflux.

We retrospectively evaluated the data of 99 patients (198 limbs) with signs and symptoms of venous insufficiency of both lower limbs from January 2016 to December 2016. We performed ultrasound to examine the venous reflux and to measure the diameter of the GSV. The GSV was divided into four locations: saphenofemoral junction, midthigh, lower thigh (LT), and below the knee. The patients were divided into two groups according to the presence or absence of reflux.

There were 87 limbs that had venous reflux and 111 limbs that had no reflux. The diameter of the GSV with reflux was significantly larger than that of GSVs without reflux only at the LT (4.7 mm vs 4.2 mm; P < .001), and the highest area under the receiver operating characteristic curve was 0.642 at the LT. The cutoff value of the LT diameter for association with reflux was 5 mm (P = .025).

The cutoff diameter of the LT was 5 mm. We recommend treatment of symptomatic reflux, and LT diameter may be useful for follow-up before and after treatment.