2Sawada Y, Kudo H, Sone K. Cause of closed suction drainage tube obstruction and its prevention using a tube coated on the inside with a silicone gel drung delivery system. Br J Plast Surg, 1991 : 44 : 589.
3Pitt HA, Gomes AS, Lois JF. Does preoperative percutaneous biliary drainaga reduce oprative risk or increas hospital cost Ann Surg, 1985:201:545.