The invention relates to a drainage system made up of a drainage tube, a coupling and a drainage hose, in which the drainage hose is made up of a profile that runs along the entire length thereof. The profile of the drainage hose is made up of three symmetrical lobes defined therebetween by three dividing channels. Each lobe is made up of two radial straight walls at the centre of the hose structure and two circumferential curved walls in opposite directions at the periphery of the hose, each radial straight wall is connected to a circumferential curved wall, and a space is formed between the two circumferential curved walls. The radial straight walls and the circumferential curved walls define a lumen the other side of the radial straight walls defines the dividing channels. The configuration of the drainage hose provides suitable structural strength that can withstand the medical uses of the part, optimising the flow of the drainage fluid, avoiding the risk of any blockage or "sealing" of the drain caused by deposition of the extracted fluids, and preventing complications for the patient when removing the drain from the patient.La invención se refiere a un sistema de drenado compuesto por un tubo de drenado, un cople y una manguera de drenado, en donde la manguera de drenado está conformada por un perfil que corre a lo largo de toda su longitud. El perfil de la manguera de drenado está compuesto por tres lóbulos simétricos delimitados entre sí por tres canales divisores. Cada lóbulo está compuesto por dos paredes rectas radiales al centro de la estructura de la manguera y dos paredes curvas circunferenciales en direcciones encontradas en la periferia de la manguera, cada pared recta radial está unida a una pared curva circunferencial, un espacio se forma entre ambas paredes curvas circunferenciales. Las paredes rectas radiales y las paredes curvas circunferenciales definen un lumen, el otro lado de las paredes rectas radiales define los canales divisores. La confi
