By Caitlin E. Cox

A catheter-based device that disperses thrombolytic solution directly into the clot of patients with deep vein thrombosis (DVT) appears safe and effective, according to new short-term follow-up data from 2 company-sponsored studies.

The device, called the Trellis-8 infusion catheter (Bacchus Vascular Inc., Santa Clara, CA), was approved by the Food and Drug Administration in 2005 for use in the peripheral vasculature and is more commonly used to treat peripheral arterial occlusions. However, the device can also help treat DVT.

“Standard therapies [for DVT] are simply anticoagulation and bed rest,” Gerard J. O’Sullivan, MB, of University College Hospital (Galway, Ireland), told TCTMD in an e-mail communication. “Coumadin and heparin do not attack the clot; they merely decrease the risk of proximal propagation.”

Trellis is among several devices being developed as alternatives to catheter-directed thrombolysis, which is sometimes used as an adjunct to anticoagulation in more severe DVT cases.

On March 16, 2008, at the 33rd annual meeting of the Society of Interventional Radiology, Dr. O’Sullivan presented data from the largest commercial registry using the Trellis device to date. Alongside coauthor Mahmood K. Razavi, MD, of Stanford University Hospital (Stanford, CA), he gathered details on a total of 565 limbs treated in 532 patients between February 2005 and August 2007 at several international sites.

The researchers reported no adverse events in the acute follow-up period, typically 24 hours. Veins were successfully opened in all cases. In 88% of patients, adjunctive measures such as venous angioplasty and/or stenting were necessary.

Another study on the Trellis device, also coauthored by Dr. Razavi, appears in the March 2008 issue of the Journal of Vascular and Interventional Radiology (JVIR). He and Daniel E. Hilleman, PharmD, of the Creighton University Cardiac Center (Omaha, NE), compared Trellis registry data in 147 patients with a meta-analysis of 14 published studies on catheter-directed thrombolysis, measuring technical success, bleeding complications, and cost of treatment, with most endpoints favoring Trelllis (table 1).

Table 1: Trellis-8 Infusion Catheter vs. Conventional Catheter-Directed Thrombolysis

*A measure of DVT treatment success defined according to the National Venous Registry scale

Cost of therapy averaged $5,473 for conventional thrombolysis and $3,697 for Trellis. “The reason the Trellis-based therapy was less costly is primarily that [catheter-directed thrombolysis] is really expensive and causes a small but important percentage of patients to have bleeding. With the Trellis they use so little thrombolytic that there’s no bleeding and cost for the drug is minimal,” Dr. Hilleman told TCTMD in a telephone interview, adding that the Trellis device also requires less time in the catheterization lab.

Neither the registry nor the JVIR study, however, measured long-term safety and efficacy for the device. “I think that the real question overall, the big picture question is, does an aggressive catheter-based approach to treating DVT have merit? Are there patients where this intervention is superior to a more conservative anticoagulation regimen?” said Dr. Hilleman. “I don’t know that we have an answer to those quesitons.”

1. O’Sullivan GJ, Razavi MK. An endovascular approach to deep venous thrombosis utlilizing isolated thrombolysis and adjunctive measures. 33rd Annual Scientific Meeting of the Society for Interventional Radiology. 2008; abstract No. 4.

2. Hilleman DE, Razavi MK. Clinical and economic evaluation of the Trellis-8 Infusion Catheter for Deep Vein Thrombosis. J Vasc Interv Radiol 2008;19:377-383.