An implant for regulating fluid flow comprising: a tube comprising an inlet end, an outlet end, and a tube passage extending between the inlet end and the outlet end for permitting fluid to flow through the tube passage； and absorbable material located within the tube passage, wherein initially the absorbable material serves to partially or wholly obstruct flow through the tube passage and wherein the absorbable material erodes as it contacts fluid such that the obstruction of flow through the tube passage is reduced over time.
