Small saphenous vein: where does reflux go? Veia safena parva: para onde se dirige o refluxo?

Background: The anatomy of small saphenous vein (SSV) is very variable because of its complex embryological origin. SSV incompetence often causes reflux that goes to the perforating veins, sometimes not respecting the anatomical course. Objective: To analyze differences in reflux direction and reentry in the SSV. Methods: In this prospective, observational study, 60 lower limbs with SSV incompetence of 43 patients were assessed using a color Doppler ultrasound protocol. Results: Reentry variations were grouped into four types and subtypes. Percentage results were: Type A, perforating veins on the medial side = 25/60 cases (41.66%); subtypes: Cockett, Sherman, paratibial and vertex; Type B, lateral malleolus and perforating veins on the lateral side (fibular 17-26 cm) = 15/60 cases (25%); subtypes: fibular and malleolus; Type C, two branches = 19/60 cases (31.66%); subtypes: gastrocnemius and Cockett, gastrocnemius and malleolus, and/or fibular, Cockett and malleolus, Cockett-vertex and fibular; Type D, reflux in the superficial system = 1/60 cases (1.66%). Conclusion: On most of the lower limbs assessed, reflux did not follow the classical anatomic course. Our findings demonstrated a high degree of variation in reflux/reentry, but no SSV anatomical variations. Reflux seems to, either look for the most accessible anatomical connection for reentry or be originated in the distal area and then reach the SSV.