Answer
Access to the iliofemoral venous circulation is usually obtained via the popliteal vein, using ultrasonographic guidance, although the common femoral, tibial, or internal jugular veins are also used. When thrombolysis is planned, use of ultrasonography and a micropuncture 21-gauge needle are recommended to minimize bleeding risk. [15]
Diagnostic venography is used to identify the extent of DVT. Fluoroscopic guidance is the most accurate and straightforward means of placing infusion catheters or devices. A sheath is placed, and a multiple–side-hole catheter or wire is used to maximize delivery of the thrombolytic agent to the surface area of the thrombus.
During thrombolysis, patients remain on bed rest, with frequent monitoring of vital signs and puncture sites performed. Pericatheter oozing, enlarging hematoma, or evidence of gastrointestinal or genitourinary bleeding warrant immediate attention. Additional punctures, particularly arterial or intramuscular ones, should be avoided.
A separate IV access facilitates blood sampling, which is performed at 6-hour intervals to monitor the patient’s hematocrit; platelet count; activated partial thromboplastin time (aPTT), if concomitant heparinization is used; and possibly fibrinogen values. Monitoring of fibrinogen levels is controversial, although levels < 4.4 µmol/L (150 mg/dL) might indicate a clinically significant systemic effect.
