A venous nitinol embolization insert for restricting blood flow includes a tubular member and an embolization material attached to the tubular member. The embolization insert provides a predetermined blood flow rate based on experimental data. A method of controlling restriction of blood flow to a targeted vascular site within a patient's body includes selecting an insert that provides a predetermined blood flow rate corresponding to a desired blood flow rate. The embolization insert is selected from a plurality of embolization inserts that provide varied blood flow rates.