The multicenter partnership, led by OHSU pediatric cardiologist David Sahn, M.D., a pioneer of echocardiography, was awarded a $7.8 million Bioengineering Partnership grant by the National Heart, Lung and Blood Institute of the National Institutes of Health. The unique team includes General Electric, University of Michigan, Pennsylvania State University, JOMED (EndoSonics) and Irvine Biomedical, Inc., all leaders in the development of biomedical equipment and cardiac catheterization. Sahn spent seven years forming this unique team and securing NIH funding. According to the NIH, the grant program was designed to encourage multidisciplinary teams of engineers, scientists and clinicians to solve medical and biological problems within a five - to10 - year timeframe.
"This feels great and is a real affirmation in recognizing that they believe in our vision," said Sahn, professor of pediatrics (cardiology) in the OHSU School of Medicine. "The most exciting element will be to integrate therapy with imaging, which we expect to be more efficient and improve patient outcomes."
The core of the five-year grant will be to develop three types of miniaturized ultrasound devices that can be inserted into the heart to provide treatment through a single catheter. Catheters act as long tunnels that allow physicians to access areas inside the body and provide treatment through tiny, pin-hole incisions, instead of invasive surgeries. Ultrasound devices, which use high-frequency sound waves to help physicians look inside the body, are currently inserted down a patient's throat during cardiac procedures to view the heart from behind while medications or impulses are administered via catheter. Producing an ultrasound image through a catheter already in the heart, rather than a patient's throat, can greatly improve patient outcomes while eliminating the need for anesthesia as well as reducing procedure duration, radiation exposure and cost. Other intracardiac catheter ultrasound systems have been developed, but they are expensive and are not reusable. Also, a separate catheter is needed in addition to the ultrasound device to provide additional testing and treatment of the heart condition.
Some of the most common cardiac catheter procedures use an electric charge to correct abnormal heart rhythms, which are prevalent in the elderly. More than one million of these procedures are performed each year, and that number will increase as the population ages. Sahn hopes the new ultrasound devices will allow these procedures to be performed in less time, at less cost and with less risk to the patient.
The first of the Sahn team's ultrasound devices will look like a hockey stick when fully extended, with ultrasound channels on the side of the tip. The device will include Doppler imaging, which tracks the movement of the heart's walls -- a vital tool in determining where an abnormal heart rhythm originates so those tissues can be removed as precisely as possible without damaging surrounding cells. All three devices will feature this type of imaging. This first device will offer a large two-dimensional (2-D) view of the heart, high ultrasound frequency and will be equipped to record abnormal electrical currents of the heart.
The second ultrasound device will retain the hockey-stick shape with the ultrasound channels positioned on the tip offering a smaller 2-D view, but a higher frequency ultrasound. This device will have the ability to not only detect and locate abnormal electrical currents in the heart, but also to treat them by burning the cells generating the abnormal charge.
The final device will take a revolutionary approach, with a ring of ultrasound channels inside the tip, surrounded by the electrical testing and treatment region. The ring configuration provides an extra opening where a separate smaller, more flexible treatment catheter can be inserted. This allows the physician to use moving 3-D ultrasound images inside the heart to guide and place the smaller catheter in intricate areas of the heart generating the arrhythmia. At the same time the physician can treat the abnormal heart rhythm more accurately using these detailed images.
Once developed, each device will be tested on pigs before undergoing human clinical trials. During the last three years of the study, the team plans to test the devices on 40-60 patients each year. The team hopes the devices' extremely small size will also make them an effective ultrasound tool for use in children and infants.
Sahn has worked on developing new ultrasound methods for children and newborns for almost 30 years. During that time, with NIH funding, he helped create one of the first high frequency minaturized ultrasound probes for imaging babies. Sahn hopes the ultrasound technology developed with this grant will be used for diagnosis and treatment of other conditions throughout the body for which a small probe for imaging and treatment might replace major surgery.
VISUALS: Photos of one of the proposed devices and of David Sahn, M.D., are available on the OHSU Web site at http://www.