The anatomy of the small saphenous vein: Fascial and neural relations, saphenofemoral junction, and valves

Abstract

Varicose veins are a frequent burden, also in the small saphenous system. Yet its basic anatomy is not described consistently. We therefore investigated the fascial and neural relationships of the small saphenous vein (SSV) as well as the frequency and position of valves and the different junctional patterns, also considering the thigh extension. We dissected the legs of 51 cadavers during the regular dissection course held in winter 2007 at Innsbruck Medical University, with a total of 86 SSVs investigable proximally and 94 SSVs distally. A distinct saphenous fascia is present in 93 of 94 cases. It starts with a mean distance of 5.1 cm (SD 1.2 cm) proximal to the calcaneal tuber, where the tributaries to the SSV join to form a common trunk. The neural topography at the level of the gastrocnemius muscle's origins shows the medial sural cutaneous nerve in 88% medially and in 12% laterally to the SSV, the tibial nerve in 64% medially and in 36% laterally, and the common fibular nerve in 98% medially and in 2% laterally to the vein. The saphenopopliteal junction (SPJ) resembled in about 37% type A (UIP-classification), 15% type B, and 24% type C. A total of 17% of specimens showed a venous web or star at the popliteal fossa and 6% had a doubled junction. A thigh extension could be demonstrated in about 84%. A most proximal valve was present in only 94% at a mean distance of 1.2 cm (SD 1.4 cm) to the SSVs orifice. A consecutive distal valve was only present in 65% with a mean distance of 5.1 cm (SD 2.3 cm). Two fascial points or regions can be described in the SSVs' course and its own saphenous fascia is demonstrated macroscopically in almost all cases. The neural topography is highly individual. The SPJ is highly individual where we found hitherto unclassified patterns in a remarkable number of veins. Venous valves are not as frequent as we supposed them to be. Furthermore, not all most proximal valves seem to be terminal valves.