Fascial relations and structure of the tributaries of the saphenous veins.

The objective was to define planar anatomy, fascial relationships and structure of the tributary vessels (TVs) of the saphenous veins (SVs). The gross anatomy of the TVs was evaluated by dissection in cadaver limbs and by sonography and computerized tomography in healthy volunteers. Correlated light microscopy and scanning electron microscopy were used to evaluate and compare the wall structure in 45 specimens of SVs and 122 specimens of TVs. The TVs showed a subdermal path and were surrounded by an amorphous fatty tissue. Only the "Giacomini's vein" and the cranial segment of the "anterior accessory saphenous vein" ran deeply in the hypodermis, ensheathed by the muscular fascia and the membranous layer of the hypodermis. The wall of the TVs was weaker than that of the SVs due to the absence of intimal hyperplasia, to lesser muscularization and to scarce connective tissue proliferation. The absence of any fascial ensheathing and the parietal weakness are suggestive of a lower resistance of the TVs wall to increased endovascular pressure. This would explain why varicose changes occurring in the TVs are usually greater than those occurring in the affected SVs.