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Intraclot alteplase injection an option for treating lower extremity DVT
As an alternative to continuous-infusion thrombolytic regimens, direct intraclot injection of alteplase is a suitable treatment for deep vein thrombosis (DVT) of the lower extremity that limits systemic exposure to thrombolytic agents, new research indicates.
As reported in the February issue of Radiology, Dr. Richard Chang and colleagues from the National Institutes of Health in Bethesda, Maryland, assessed the outcomes of 20 patients with first-onset acute DVT who were treated with intraclot alteplase plus systemic anticoagulation.
According to the authors, alteplase was selected because of its high fibrin affinity, which obviates the need for administration with continuous infusion.
Resolution of antegrade blood flow was achieved in 16 patients during thrombolytic therapy and 18 patients were symptom-free after six months of anticoagulation therapy, the report indicates.
Rapid clearance of circulating alteplase was noted on pharmacokinetic testing and plasminogen activator inhibitor-1 levels recovered within two hours of stopping the drug.
Pretreatment V/Q scans identified seven patients with a high probability of pulmonary embolism. Following treatment, three patients had high probability scans, including two who had pretreatment normal/low probability scan. None of the patients experienced a clinical significant pulmonary embolism or serious bleeding while receiving thrombolytic therapy.
No cases of postthrombotic syndrome or recurrent thromboembolism were noted during an average follow-up period of 3.4 years.
"Our study results indicate that the doses we tested can be effective, without causing major bleeding complications, but our funding allowed us to study only 20 patients. There is no evidence that the doses used in our study are optimal doses, and other dose regimens should be investigated before much-needed larger clinical trials to demonstrate safety are begun," Dr. Chang's team concludes.