Because catheter is aggravating oedema of bladder mucous membrane, haemorrhage is necrotic, accentuated infection, the bacterium is kept clear of very hard in cystic mucous membrane.

• 因为导尿管加重了膀胱粘膜水肿、出血坏死，加重了感染，细菌在膀胱粘膜里很难被清除。