PURPOSE: To establish the optimal protocol of heparin administration during interventional neuroradiology. METHODS: We assessed 100 cases of neuroangiography, including endovascular surgery, and measured activated coagulation time before and 5 minutes after heparin administration, and before and 5 minutes after protamine neutralization. In some cases actual heparin concentration was assayed using a chromogenic substrate technique. RESULTS: The actual plasma heparin concentration significantly correlated with the dose of heparin administered intravenously (r = .98; P < .0001) and changes in activated coagulation time (r = .85; P < .0001). The change in activated coagulation time significantly correlated with the dose of heparin injected intravenously (r = .54, P < .0001). The ratio of change in activated coagulation time significantly correlated with time elapsed after heparin administration (r = -.70, P < .0001). CONCLUSIONS: The activated coagulation time is useful in monitoring administration and neutralization of heparin during neuroangiography, and a bolus injection of 60 U/kg heparin should be adequate to carry out neuroangiography for 75 minutes safely, even for endovascular surgery.
PURPOSE: To establish the optimal protocol of heparin administration during interventional neuroradiology. METHODS: We assessed 100 cases of neuroangiography, including endovascular surgery, and measured activated coagulation time before and 5 minutes after heparin administration, and before and 5 minutes after protamine neutralization. In some cases actual heparin concentration was assayed using a chromogenic substrate technique. RESULTS: The actual plasma heparin concentration significantly correlated with the dose of heparin administered intravenously (r = .98; P < .0001) and changes in activated coagulation time (r = .85; P < .0001). The change in activated coagulation time significantly correlated with the dose of heparin injected intravenously (r = .54, P < .0001). The ratio of change in activated coagulation time significantly correlated with time elapsed after heparin administration (r = -.70, P < .0001). CONCLUSIONS: The activated coagulation time is useful in monitoring administration and neutralization of heparin during neuroangiography, and a bolus injection of 60 U/kg heparin should be adequate to carry out neuroangiography for 75 minutes safely, even for endovascular surgery.