For Referring Physicians
Newsletter

January 1999

New Advances in Treating Extensive Ilio-Femoral DVT

Deep vein thrombosis (DVT) is responsible for significant morbidity, mortality, and health care costs in the United States due to pulmonary emboli, chronic venous insufficiency, and post-phlebitic syndrome. In recent years significant advances have been achieved in diagnosing and treating patients with extensive deep vein thrombosis. Non-invasive duplex ultrasound with colorflow Doppler remains the best choice for diagnosing DVT and has all but replaced conventional ascending venography.

Traditionally DVT has been treated using I.V. unfractionated heparin followed by administration of oral sodium warfarin. New treatments utilizing low-molecular weight heparin may eliminate the need for hospitalization during the initial period of anticoagulation. A major misconception, however, is that "thinning the blood" helps dissolve thrombus. Anticoagulation does not promote thrombolysis, but is merely prophylactic and prevents thrombus propagation which will reduce the risk of pulmonary emboli, and attempt to minimize the long-term sequelae of DVT, ie. post-phlebitic syndrome ( chronic leg edema, pain, skin discoloration, venous claudication, and venous stasis ulcers).

Numerous trials have shown a significant number of patients with acute DVT will develop long term sequelea. This is a result of obstruction of the deep venous system and damage to the venous valves in the lower extremity. These two processes lead to ambulatory venous hypertension which causes persistent leg edema and if not properly managed, may eventually lead to the advanced stage of post-phlebitic syndrome. Once the patient develops the advanced stage of this disease process, there is significant disability, socio-economic implications, and increased utilization of health care resources.

While heparin and warfarin prevents further thrombus formation, they cannot activate thrombolysis directly. The venous system can spontaneously lyse small clot through autologous pathways but is often overwhelmed where there is extensive thrombosis, especially DVT that involves the large diameter iliac and femoral venous systems. New advances in catheter-directed thrombolysis using urokinase seem to be a better form of treatment of proximal lower extremity DVT than anticoagulation alone. Patients with DVT are less likely to develop valvular incompetence if early and complete recanalization is obtained.

The optimal management of DVT has not yet been defined. It is clear that standard therapy with heparin/warfarin sodium is sufficient for symptomatic palliation, but insufficient to prevent the long term sequelea of chronic venous insufficiency. Preliminary reports of catheter-directed urokinase thrombolysis for DVT are encouraging. Our experience in using this technique in the iliofemoral region seems to confirm these reports.

If you have any questions regarding this new technique, please feel free to contact us at any time.

Thank you for your continued support!