What is the reason for the swelling in the leg after the flap replacement surgery? Generally, there is no leg edema when discharged from the hospital after valve replacement surgery, unless bypass surgery is done at the same time and a blood vessel is removed from the lower leg, then there will be a certain degree of edema in the lower leg where the blood vessel is removed, which is a normal phenomenon. If edema of both lower limbs occurs after a period of time after being discharged from the hospital and returning home, it is generally considered to be related to drinking too much water and cardiac insufficiency, and needs to go to the hospital as soon as possible for consultation and treatment. At the same time, we should also consider that the lower limbs may be caused by vascular lesions, and need to go to the hospital for detailed examination and treatment.