This was a Phase IV, open-label, single-arm, multicenter trial that was to be conducted at ~60 sites in the United States. Approximately 300 pediatric subjects with dysfunctional CVADs (including catheters with valves, multiple lumens, umbilical catheters, and implanted ports) were to be treated with up to two serially instilled doses of Cathflo Activase.

Inclusion Criteria:

Subjects had to meet the following inclusion criteria to be eligible for study entry:

• Less than 17 years of age
• Clinically stable
• Occlusion of CVAD (including catheters with valves, multiple lumens, umbilical catheters, and implanted ports)
• For subjects who weighed >= 10 kg, inability to withdraw 3 mL of blood from the CVAD
• For subjects who weighed < 10 kg, inability to withdraw 1 mL of blood from the CVAD
• Ability to infuse fluids at the volume necessary to instill Cathflo Activase into the CVAD
• Written informed consent and assent (if appropriate) provided by parent or legal guardian and compliance with study assessments for the full duration of the study

Exclusion Criteria:

• Ability to withdraw blood following subject repositioning
• CVAD insertion < 48 hours prior to enrollment
• Selected study catheter implanted specifically for hemodialysis
• Evidence of mechanical, non-thrombotic occlusion of the CVAD (e.g., kink in the CVAD or suture constricting the catheter)
• Previous enrollment in this study
• Use of fibrinolytic agent (e.g., alteplase, reteplase, tenecteplase, urokinase, streptokinase) within 24 hours of enrollment
• At high risk for bleeding events, embolic complications (i.e., recent pulmonary embolism, deep vein thrombosis, endarterectomy, clinically significant right-to-left shunt) in the opinion of the investigator, or with known condition for which bleeding constituted a significant hazard
• Known hypersensitivity to alteplase or any component of the formulation