New Heart-Lung Bypass System Avoids Harmful Effects of Conventional Machines For Coronary Bypass

A new, compact heart-lung
bypass system was shown to be safe and effective in reducing the blood trauma
and morbidity often associated with conventional heart-lung machines, surgeons
reported today.

In a feasibility study for the system’s manufacturer, CardioVention Inc.,
of Santa Clara, Calif., Valavanur Subramanian, M.D., chairman of the
department of surgery at New York’s Lenox Hill hospital, Jose Navia, M.D.,
chief surgeon at Hospital Austral in Buenos Aires, and a medical team from the
Cleveland Clinic Foundation, tested the CORx™ System in seven patients who
each underwent a coronary artery bypass procedure.

Initial results showed that, compared to the blood circuitry of today’s
much larger heart-lung bypass machines, the small unit — slightly larger than
a coke can — is able to function with one-tenth the amount of surface area
exposed to blood and with minimal to no priming volume required for activating
the system. The effect of priming, known as “hemodilution,” thins the
patient’s blood, reduces its oxygen carrying capacity and compromises other
body functions. By reducing hemodilution and the surface area exposed to
blood, the new system is expected to play a critical role in minimizing
platelet loss, blood damage, blood transfusions and systemic inflammation.
“This is the first major advance in heart-lung bypass technology in more
than 20 years,” said Dr. Subramanian. “Using the CORx heart-lung machine is
like going from a mainframe computer to a laptop. While the data is still
under evaluation, the system functioned remarkably well in oxygenating blood,
removing carbon dioxide, providing adequate circulation and taking over the
heart and lungs during bypass surgery. Because the system maintained excellent
hemodynamics, it should enable better heart access in beating-heart
procedures.”

Heart-lung machines, also known as cardiopulmonary bypass (CPB) systems,
allow surgeons to perform surgical procedures that require the heart and lungs
to be completely shut down. CPB attempts to duplicate the functions of the
heart and lungs by providing blood flow and the exchange of oxygen and carbon
dioxide. Although CPB has enabled the widespread adoption of such surgical
procedures as coronary artery bypass grafting and heart valve replacement and
repair, studies have shown CPB can have harmful short- and long-term effects
on the patient. These include the risk for stroke, memory loss, as well as
immunosuppression, systemic inflammation, post-operative blood loss and organ
dysfunction.

Although cardiac surgeons have tried alternative procedures such as
“beating-heart surgery” to avoid these problems, these techniques are much
more difficult and not applicable to all cardiac patients, thereby limiting
their prevalence. Avoiding the harmful effects of conventional CPB, the CORx
System may enable these and other more difficult minimally invasive procedures
to be performed by providing assisted heart-lung support on an intermittent or
continual basis.

“The results look very encouraging and exceeded our expectations,” said
Delos Cosgrove, M.D., chairman of the department of cardiovascular surgery at
the Cleveland Clinic Foundation and a member of CardioVention’s scientific
advisory board. “Given the CORx System’s much smaller blood-flow circuitry
compared to conventional heart-lung machines, we can expect major benefits to
the patient and the surgeon over a wide-range of cardiac procedures.”

For use in both traditional stopped-heart and beating-heart surgery, and
for valve replacement and repair procedures, the CORx System was designed to
avoid many of the deleterious effects of current heart-lung bypass technology.
Because of its small and efficient size, the system’s fluid circuitry
minimizes foreign surface contact, while providing optimal oxygen and carbon
dioxide transfer and maximum micro-air filtration.

“The CORx System was simple and easy to use and has clinical benefits for
both stopped- and beating-heart surgery,” said Dr. Navia. “In our first
patient who underwent a triple bypass, the CORx System only required 100 cc of
hemodilution rather than the 2,000 cc typically needed with a standard CPB.
Platelet count showed only an 8% decline compared to 50%-90% one sees with
conventional systems. If we can negate the detrimental effects of hemodilution
and priming, we can expect a major reduction in lung congestion and bleeding
and faster overall recovery.”

Earlier this month, CardioVention received ISO 9001 certification and the
CORx System received a CE Mark recommendation, establishing a regulatory path
for European marketing clearance.

About CardioVention Inc.
An emerging leader in minimally invasive technologies, CardioVention, of
Santa Clara, Calif., is a privately held developer of the CORx line of
cardiopulmonary bypass products. Aimed at the $1 billion-dollar annual
cardiovascular surgery market, the company’s products are designed to avoid
many of the harmful effects of current heart-lung machine technology.