Public Release: 

Temple-led research analyzes impact of case volume on outcomes for DVT treatment

Temple-led research found higher institutional case volume is associated with improved outcomes for catheter-based blood clot removal in patients with deep vein thrombosis of the legs

Temple University Health System

(Philadelphia, PA) - Patients who have lower extremity proximal deep vein thrombosis (LE-DVT), or a blood clot in their leg, are increasingly undergoing minimally invasive catheter-based blood clot removal - also referred to as catheter-directed thrombolysis (CDT) - rather than solely being treated with traditional blood-thinning medications (anticoagulation alone). This trend is due to recent literature showing reductions in lifestyle-limiting post-thrombotic complications of acute DVT in patients who undergo CDT compared to those that are treated with anticoagulation alone. One of those complications is post thrombotic syndrome, or PTS, a very frequent and disabling complication of DVT which is characterized by pain, swelling, itching, skin discoloration and heaviness in the legs and, in severe cases, skin ulcers.

Despite its benefits, however, nationwide data from the United States has shown CDT to be associated with increased bleeding complications. Riyaz Bashir, MD, Professor of Medicine at Temple University School of Medicine and Director of Vascular and Endovascular Medicine at Temple University Hospital, led a study aimed at determining whether those increased bleeding complications were correlated with the volume of CDT procedures performed at a particular institution.

The study, published online this week by leading cardiology journal Circulation, found that a higher volume of CDT cases annually was associated with lower in-hospital mortality rates and lower intracranial hemorrhage rates.

"These findings have potentially major future implications for the treatment of deep vein thrombosis," says Dr. Bashir. "For the first time we have shown a significant inverse relationship between the institutional CDT volumes and adverse outcomes like death and intracranial hemorrhage."

Dr. Bashir and his team used the Nationwide Inpatient Sample (NIS) database to identify 90,618 patients admitted to U.S. hospitals with an LE-DVT diagnosis from 2005 to 2010. They further narrowed that group down to 3,649 patients treated with CDT. The researchers then divided the hospitals into two groups: high volume centers, which performed six or more CDT procedures per year, and low volume centers, which performed less than six CDT procedures per year.

Dr. Bashir and his team found that in-hospital mortality in patients treated with CDT was significantly lower at high volume centers (0.6% vs. 1.5%) compared to low volume centers, and that intracranial hemorrhage rates were less than half at high volume centers (0.4% vs. 1.0%) as they were at low volume centers.

"This does not mean that low volume centers should not perform CDT for patients with LE-DVT," says Dr. Bashir. "It means that we should focus on standardizing CDT protocols that include careful patient selection as well as peri-procedural patient monitoring. In addition, establishment of centers of excellence in treating venous thromboembolic disease may provide the necessary framework within which bleeding risk to the patient can be minimized."

Dr. Bashir says the next step should be to focus on lowering these bleeding complication rates at low volume centers by standardizing their CDT protocols. Also, patients with leg DVT - especially young patients - should feel comfortable considering clot removal, particularly at a high volume center, as a viable option to prevent post thrombotic syndrome. "Our overall goal is to treat these DVT patients early on and prevent post-thrombotic syndrome and its adverse consequences on the quality of life. We feel this research provides more clarity and direction in identifying the best strategies for how to achieve that goal," Dr. Bashir adds.

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In addition to Dr. Bashir, authors on the paper include:

Temple University School of Medicine: Harish Jarrett, Vikas Aggarwal, Mohammad A. Alkhouli, Alfred A. Bove, Vladimir Lakhter, Huaqing Zhao.

Mayo Clinic: Chad J. Zack.

ProMedica Toledo Hospital: Anthony Comerota.

About Temple Health

Temple University Health System (TUHS) is a $1.8 billion academic health system dedicated to providing access to quality patient care and supporting excellence in medical education and research. The Health System consists of Temple University Hospital (TUH), ranked among the "Best Hospitals" in the region by U.S. News & World Report; TUH-Episcopal Campus; TUH-Northeastern Campus; Fox Chase Cancer Center, an NCI-designated comprehensive cancer center; Jeanes Hospital, a community-based hospital offering medical, surgical and emergency services; Temple Transport Team, a ground and air-ambulance company; and Temple Physicians, Inc., a network of community-based specialty and primary-care physician practices. TUHS is affiliated with Temple University School of Medicine.

Temple University School of Medicine (TUSM), established in 1901, is one of the nation's leading medical schools. Each year, the School of Medicine educates approximately 840 medical students and 140 graduate students. Based on its level of funding from the National Institutes of Health, Temple University School of Medicine is the second-highest ranked medical school in Philadelphia and the third-highest in the Commonwealth of Pennsylvania. According to U.S. News & World Report, TUSM is among the top 10 most applied-to medical schools in the nation.

Temple Health refers to the health, education and research activities carried out by the affiliates of Temple University Health System (TUHS) and by Temple University School of Medicine. TUHS neither provides nor controls the provision of health care. All health care is provided by its member organizations or independent health care providers affiliated with TUHS member organizations. Each TUHS member organization is owned and operated pursuant to its governing documents.

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