June 10, 2004 — Pharmacomechanical catheter-directed thrombolysis with reteplase and the Helix mechanical thrombectomy device followed by early stent placement is a safe and effective treatment for iliofemoral deep vein thrombosis (DVT), according to results of a retrospective study published in the June issue of the Journal of Vascular and Interventional Radiology.
Previously, catheter-directed thrombolysis of iliofemoral DVT involved intrathrombus infusion of urokinase until complete thrombolysis was achieved, followed by balloon venoplasty and/or stent placement to treat residual stenosis.
According to Suresh Vedantham, MD, and colleagues of the Mallinckrodt Institute of Radiology and the Department of Surgery at the Washington University School of Medicine in St. Louis, Missouri, this effective method of restoring deep venous patency had several limitations to widespread use. These included major complications such as bleeding (mean, 11%), long infusion times (mean, 53 hours), and significant hospital costs due to monitoring requirements.
The investigators examined the use of catheter-directed reteplase with two adjunctive measures to decrease the required dose and infusion time. First, the Helix mechanical thrombectomy device was used to accelerate removal of long segments of residual thrombus after initial thrombolysis. Second, "early stent placement" was employed instead of continued thrombolytic infusion to eliminate shorter segments of residual acute iliac vein thrombus.
Twenty-three symptomatic limbs in 18 patients with iliofemoral DVT were treated with reteplase catheter-directed thrombolysis over a 39-month period. After an initial eight- to 16-hour infusion, residual acute thrombi more than 10 cm in length were macerated using the Helix thrombectomy device. Residual short-segment (<10 cm) iliac vein thrombi and/or stenoses were treated with stent placement. All patients received subtherapeutic heparin (300-500 U/hour) through the vascular sheath.
Technical success, defined as successful restoration of venous patency with residual stenosis of less than 30%, was achieved in all 23 limbs (100%).
Clinical success, defined as the presence of technical success in conjunction with considerable improvement in lower extremity swelling and/or pain lasting at least three days or until discharge, was achieved in 22 (96%) of 23 limbs.
Complete (grade 3), partial (grade 2), and minimal (grade 1) thrombolysis was observed in 31%, 52%, and 17% of limbs, respectively. According to the authors, this is comparable to the effects achieved with use of urokinase.
The mean thrombolytic infusion time per limb was 19.6 hours ± 8.1hours and the mean total dose per limb was 13.8 U ± 5.3 U reteplase.
Mean serum fibrinogen nadir and percentage drop in serum fibrinogen were 282 mg/dL ± 167 mg/dL and 47% ± 24%, respectively. Major bleeding requiring blood transfusion occurred in one patient (6%).
Follow-up of 18 limbs in 15 patients (mean, 19.8 ± 11.6 months) showed six limbs to be asymptomatic. Late-day ambulatory edema occurred in 10 limbs, and moderate continuous edema with intermittent aching was present in two limbs.
"Most treated patients were asymptomatic or only slightly symptomatic at a mean follow-up interval of almost 2 years," the authors write. "[P]harmacomechanical thrombolysis with early stent placement merits further exploration in controlled, prospectively-designed studies with defined protocols for pharmacological thrombolysis, mechanical thrombectomy, and stent placement, as well as validated measures of health-related quality-of-life and venous disease severity."
Dr. Vedantham is an unpaid member of an advisory board to Genentech. No other conflicts of interest were disclosed.
J Vasc Interv Radiol. 2004;15:565-574
Reviewed by Gary D. Vogin, MD
Medscape Medical News © 2004
Cite this: Yael Waknine. Pharmacomechanical Thrombolysis and Early Stent Placement Effective for Iliofemoral DVT - Medscape - Jun 10, 2004.