9Meissner MH,Manzo RA,Bergelin RO,et al;Deep venous insufficiency :The relationship between lysis and subsequent reflux. J vasc Surg, 1993,18:596.
10Piefik E ,Tounder I ,Utk H,et al. Validation of duplex ultrasonography in detecting competent and incompetent perforating veins in patients with venous ulcertion of lower leg. J Vas Surg, 1997,26:49-52.