Disclosed are methods, devices, and systems for treating a body lumen with a sclerothepeutic agent. The method includes the steps of positioning a porous balloon assembly at a site in the lumen to be treated, inflating the assembly to establish a close approximation to the lumen wall, forcing the sclerotherapeutic agent to exit the pores and come in contact with the lumen wall, and to deflate and retrieve the balloon assembly. The methods, devices and systems disclosed herein are especially useful for the treatment of incompetent veins and their contributory branches.
