Direct Injection

Catheter-directed thrombolysis saves lives

Catheter-directed therapy, or catheter-directed thrombolysis, is an interventional radiology treatment that uses targeted image-guided drug delivery with specially designed catheters to dissolve dangerous blood clots in the lungs. Research in the November Journal of Vascular and Interventional Radiology shows that it can be a life-saving procedure and should be considered a first-line treatment option for massive pulmonary embolism. 

“Modern catheter-directed therapy for acute pulmonary embolism saves lives, and we need to raise awareness about its safety and effectiveness not only among the general public but also within the medical community. It’s a matter of life and death,” says William Kuo, MD, an interventional radiologist and assistant professor and fellowship director of vascular and interventional radiology in the Department of Radiology at Stanford University Medical Center in Stanford, Calif. “In our study, we conclude that modern catheter-directed therapy is a relatively safe and effective treatment for acute massive pulmonary embolism and should be considered as a first-line treatment option.”

During the treatment, an interventional radiologist inserts specially designed catheters through a tiny incision into one’s blood vessels and guides the catheters using real-time imaging without traditional open surgery. This allows an interventional radiologist to deliver a clot-busting medicine directly into the clot. The catheters may also be used to mechanically break up clots and suction them away.

This treatment offers less pain and less recovery time than traditional open surgery, says Kuo. 
Stanford University researchers conducted a meta-analysis of the treatment on 594 patients in 18 countries who were treated between 1990 and 2008. The treatment was lifesaving in 86.5 percent of the cases studied and had only a 2.4 percent chance of major complications. Researchers found that not only was the treatment effective, but it also appeared much safer than the historical complication rates reported from injecting high-dose clot-busting medicine systemically or directly into the blood stream where the drug can circulate throughout the body and cause major bleeding in up to 20 percent of patients.

Kuo began this study three years ago after he was asked to assist with a 62-year-old woman who had collapsed at home and was rushed to the emergency room with massive blood clots in her lungs. The patient had been given a large-dose intravenous infusion of clot-busting medicine, or systemic thrombolysis, but that had failed.

While Kuo was initially consulted to place a special filter to prevent more clots from traveling from the legs to the lungs, he knew it would do little to save her. “I remember telling the staff, ‘We can do more than just insert a filter. We can go after these clots using specially designed catheters,’” says Kuo.

– Society of Interventional Radiology