Dr. Robert J. Kennedy Described His Study of Ultrasound Accelerated Thrombolysis for the Treatment of Acute PE at ISET 2012

Q: Do you feel that further interventions are needed for the treatment of pulmonary embolism?

A: In my opinion, PE is an undertreated disease in the United States. There are approximately 600,000 cases of pulmonary embolism per year and about 60,000 deaths per year in the U.S. Many of those cases go undiagnosed but of those that are diagnosed, most are treated with anticoagulation alone as the standard of care. I believe that will change as more data becomes available about interventions for pulmonary embolism.

Q: What was the purpose of your study?

A: This study was a retrospective review of our experience in treating acute pulmonary embolism with catheter-directed techniques.

Q: What prompted you to begin this research?

A: We’ve been treating patients with catheter-directed techniques for many years. When we started using the EKOS device for pulmonary embolism, we found that we were getting better results, getting faster lysis of clot in the pulmonary arteries, and patients were doing better. The volumes of cases that we had been doing kept growing because of good results and increased referrals so we decided to go back and look at our total experience of treating more than 40 PE patients this way.

Q: How did you choose the subjects for this study?

A: We chose all of the patients that were treated with EKOS over 2.5 years but there was one patient excluded because we didn’t have follow-up imaging to document the amount of clot that had been lysed.

Q: Can you summarize your results for us?

A: Of the 40 patients in the study, there was documented symptomatic improvement in all patients, including a statistically significant decrease in systolic and mean pulmonary artery pressures. There was complete lysis of clot in two-thirds of patients and near-complete lysis in the other third. All patients survived to discharge from the hospital and there were no major complications. One patient had a retroperoneal hemorrhage that did not require transfusion.

Q: Do you see any new trends in PE?

A:  I think there is an increasing awareness of pulmonary embolism in the general public and among physicians. For a long time, it was a very difficult disease to diagnose and treat (and still is), but the trend toward more aggressive management of pulmonary embolism is starting to take off.

Q: How will smaller community hospitals handle this procedure?

A: We get referrals from several different hospitals in the community. We deal with a large volume of patients in our hospital alone, which is fairly large with over 500 beds, but we are the only ones in our community who currently perform this treatment. Many physicians in this community work at different hospitals and are referral sources that are well aware of our capabilities. I don’t think this is something that will be available in the near future at smaller hospitals as it requires significant expertise to be able to perform these types of interventions.

Q: Is there anything that we haven’t covered that you would like to add?

A:  I think we need continued study with prospective trials to evaluate both the short-term and long-term effects on pulmonary embolism in this manner. Our study focused on the immediate short-term effects and we didn’t really look at the long-term outcomes of these patients.

Q: Will you continue to look at your patients for potential long-term effects with this treatment?

A:  One of the reasons for treating pulmonary embolism aggressively is to prevent long-term adverse outcome of secondary pulmonary hypertension, which can be very debilitating. We’ll try to look at these patients in a longitudinal fashion but that may require many years of follow-up.

Dr. Robert J. Kennedy is a vascular and interventional radiologist at the Holmes Regional Medical Center in Melbourne, Florida.