Risk Factors for Thrombosis in Tunneled Double Lumen Catheter as Hemodialysis Access with Heparin Lock Administration in Chronic Kidney Disease Stage V Patients Liber Siahaan1, Ketut Putu Yasa2, and Made Mulyawan3 Abstract Aim: This study, concerning the risk factors of thrombosis on tunneled double-lumen catheters with administration of Heparin locking