Evaluation of the Clinical Anatomy of the Most Important Perforator Veins of the Lower Extremities by Dissection and Duplex Ultrasound Scanning

Abstract

Introduction - literature sources provide significant amount of data on the anatomy of the perforator veins (PVs) of the lower extremities. However, detailed descriptions of the topography of PVs are rare. Methods - 70 amputated lower extremities were subjected to anatomical dissection; 2800 patients (3500 extremities) underwent duplex ultrasound scanning (DUS). Results - There were 4 to 6 PVs on the medial surface of the foot. They directly connected the medial tributary of the medial marginal vein and vv. plantaris medialis and were located along the medial intermuscular septum. There were 2 to 3 PVs on the lateral surface of the foot. They connected the tributary of the lateral marginal vein (which together with the main trunk of the lateral marginal vein formed small saphenous vein) and vv. plantaris lateralis in a direct manner. Topographically PVs passed behind the lateral muscle group of the foot along the lateral intermuscular septum. Moreover, both PVs had tributaries, which drained the subcutaneous tissues of the lateral and medial surfaces of the foot. Presence of the muscular/venous pump of the calf complicates the structure of the PVs, among which are direct, indirect, and mixed PVs. Anatomical dissection has shown that the most constant were PVs located at a distance of 7-10 cm and 11-16cm from the lower edge of the medial ankle. Each PV of the calf (direct or indirect) and the foot was accompanied by an arterial twig, and it was often possible to identify a twig from a nearby nerve. There were 2 PVs in the subfascial area, located by the sides of the artery. PVs in the popliteal region may be referred to as “atypical” due to their rare presence (0.4% according to the DUS and no cases during dissection) in combination with the lack of a typical saphenopopliteal junction. PVs in this area were not supported by the intermuscular septa. 0.34% of the PVs emptied into the popliteal vein at the lateral side, while the small saphenous vein emptied into the great saphenous vein (GSV) at the upper 3rd of the or into the Giacomini vein. Arterial twigs accompanied every PV. DUS has shown the typical localization of the PVs on the thigh: middle third of the thigh where PVs emptied into the femoral vein at the level of the adductor canal, PVs connected GSV and femoral vein in 82.8% cases; lower third of the thigh – PVs emptied into the popliteal vein below the level of the adductor canal, PVs connected GSV and popliteal vein in 73.6% cases. All PVs passed along the medial intermuscular septum and were accompanied by an arterial branch from the femoral artery in all cases. The angle of the confluence of the PVs and the deep veins was approximately 45°, the length of their subfascial course was 5 to 7cm. Such characteristics prevent incompetence of the PVs in patients with varicose disease but create higher risks of introducing a Babcock’s probe into the deep veins in antegrade direction during phlebectomy (0.5% of cases). Conclusion - 1. Perforator veins mostly constitute the neurovascular bundles. 2. Perforator veins are primarily located along the intermuscular septa, which provides a solid support for the perforator vessels due to the rigid fixation of the intermuscular septa to the bones. 3. Presence of a concomitant artery makes it possible to propose an additional mechanism of venous outflow via the perforator vascular bundles - an arterio-venous pump.