The saphenous venous compartments.

The relationships between the connective framework of the lower extremity hypodermis and the saphenous veins was studied by dissection, stereomicroscopy, ultrasonography and histology in 64 lower limbs. A fibroelastic lamina was evidenced in the hypodermis of the medial aspect of the thigh and leg and in the back face of the leg. This lamina, together with the underlying muscular fascia, fixed the boundaries of two compartments occupied by the saphenous veins and nerves. The adventitia of the saphenous veins was connected to the compartment walls by thick connective strands. The saphenous veins ran deeply in the hypodermis, closely ensheathed by a fibroelastic sleeve. As a consequence, they could no longer be considered as a truly superficial vein. This term seems to be appropriate only for their tributaries, which ran in a more superficial plane just below the dermis. The role of the saphenous vessels in blood return from the lower limbs may be greater than classically accepted. In fact, due to their close fascial ensheathing and adventitial anchoring, muscular contractions may enhance blood flow within these vessels as occurs in the intermuscular veins. Finally, dilative pathology of the saphenous vein may be resisted by the membranous lamina as a sort of a fibroelastic shield.