Veins in the Lateral Fascial Compartment of the Calf

Abstract

Venous insufficiency mostly arises from valvular incompetence in the great saphenous vein (GSV) and small saphenous vein (SSV). However, non-saphenous reflux (NSR) remains relatively unexplored in clinical practice and ultrasound investigations. This study reports an uncommon anatomical finding and the associated venous reflux, which is believed to involve the peripheral nerve. A systematic database search was conducted to identify patients from our clinic previously diagnosed with an interfascial vein in the lateral calf compartment during duplex ultrasound examination. Subsequently, a questionnaire was distributed to those who volunteered to participate, collecting further demographic details and clinical information related to peripheral neuropathy of the calf. Ultrasound findings, including venous competency and diameter measurements, were included for data analysis. In total, 20 legs with an interfascial vein were identified from 19 patients between 2008 and 2022. Of the 6 patients who returned the questionnaire and provided consent for inclusion, 2 reported lateral calf pain in the lower calf. Calf numbness was noted in 2 patients, primarily affecting the upper and mid portions with 2 further patients reporting foot drop. Reflux flow in the interfascial vein was detected in 5 patients. Sonographic findings revealed interfascial vein diameters range from 1.1 to 4.0 mm, with a mean of 2.4 mm. The distance between the interfascial vein and SSV varied, with a mean of 36.3 mm. Based on topographic anatomy and reflux flow originating from sciatic nerve varices, we hypothesize that the interfascial vein identified in our patients likely represents the superficial peroneal nerve vein. This study sheds light on the existence of an interfascial vein in the lateral calf compartment and its role in producing lateral calf neuropathy.