OVERVIEW
The double flush technique is one that is utilized frequently in neurointerventional radiology. It is used to prevent the formation and dispersal of thromboemboli within the patient. This technique requires two heparinized saline syringes that are NOT filled all the way (leaving room for aspiration) and is used to flush equipment/catheters within the patient.
Using the first saline syringe, several mL of arterial blood is withdrawn to remove clots that might have formed in the catheter. This also allows confirmation that the catheter tip is positioned properly in the arterial lumen and not against the arterial wall, as the latter would prevent the aspiration of blood. A second saline syringe is used to forward flush the catheter, and the stopcock is turned off during forward saline injection to combat the backflow of arterial blood into the catheter tip. The “injecting” hand must always be higher than the “catheter” hand, tipping the syringe tip downward to limit the possibility of air emboli from the syringe entering into the system.