Technique shows dramatic results when treating pulmonary emboli

pulmonary artery for sciencelife
Pulmonary angiograms on a 40-year-old patient injured in a motorcycle accident

If a picture's worth 1,000 words, this before-and-after of a blood clot in a lung is worth a short novel.

The comparison, shown here through a pulmonary angiogram on a 40-year-old patient at the University of Chicago Medicine, is stark.

The left image shows the lung of Michael Sanders, a Chicago man who was injured in a motorcycle accident this fall. A catheter injects dye into the left pulmonary artery. But a large blood clot obstructs blood flow in the pulmonary artery, so the dye can't flow very far. The right image shows the same patient 48 hours later. The clot is gone and there's flow throughout the entire left lung.

Jonathan Paul, MD, an interventional cardiologist who's an assistant professor of medicine, diagnosed Sanders with a submissive pulmonary embolism. The large blood clot was straining on Sanders' heart, which in turn caused his blood pressure and oxygen saturation to fall.

"It was like every time I took a breath someone was squeezing my lungs and I couldn't get enough air to breathe," Sanders said. "I was nervous because I heard a few different stories that people can die from that." Nationwide, almost 600,000 patients are diagnosed with pulmonary emboli of varying severity each year. They cause, or contribute to, nearly 200,000 deaths annually, according to data from the Society of Interventional Radiology.

Previously, Paul would have treated patients like Sanders with intravenous heparin "and waiting."

But for the past several months, UChicago Medicine has begun using invasive therapies typically reserved for dangerous clots known as "submassive pulmonary emboli" to focus delivery of the potent clot-busting medication tPA (tissue plasminogen activator) directly within the lung. That reduces bleeding complications associated with larger, intravenous dosages of the drug.

Now, rather than treating a high-risk patient with IV heparin and time, the UChicago team is using the EKOS EkoSonic Endovascular System that couples direct drug delivery with ultrasound waves, effectively "softening" the clot. The procedure is performed in the cardiac catheterization laboratory using minimal or no sedation.

"The procedure wasn't as scary as I thought it would be," said Sanders. "I thought it would have been more work than what actually they did. It wasn't painful and it was quick and easy."

Known as "ultrasound-assisted, catheter-directed thrombolytic therapy," the procedure's results are both dramatic and fast.

"The flow through the lungs typically improves within 24 hours, as does the strain on the heart and the clinical state of the patient," Paul said.

As for Sanders, who also broke his legs in the motorcycle accident? He was discharged the next day.

"He felt 100 percent better after the therapy was complete," Paul said.

Ashley Heher
Ashley Heher

Ashley Heher is the assistant director of media relations at UChicago Medicine.