In the winter of 2009, we reported that Surgery Department Chairman Joseph B. Zwischenberger, MD and Dongfang Wang, MD, PhD, director of the Artificial Organ Laboratory, were awarded a patent for the double lumen cannula. More recently [April 28, 2009], the team has been awarded another patent for a device and system that supports a failing heart.
Commonly known as a heart attack, myocardial infarction (MI) occurs when the blood supply to the heart is interrupted. It is most frequently due to blockage of a coronary artery following a rupture or blockage in the wall of an artery. The resulting ischemia, or restriction of blood supply, and oxygen shortage causes damage and/or death of the heart muscle tissue. The prognosis for healing after an MI can be greatly affected by the efficiency and availability of providing rapid assistance to the heart to encourage healing and provide oxygenation and circulation to supply blood to the anatomy.
Current technologies utilized to support the failing heart after MI are left ventricle assist device (LVAD), extracorporeal membrane oxygenation (ECMO) and cardiopulmonary support (CPS). Though state-of-the-art, they are traumatic to the blood and body, often resulting in complications and death.
LVAD provides left ventricular support and reduces damage to the red blood cells. LVAD removes blood flowing into the left ventricle, resulting in a more relaxed state. Current technology requires insertion into both left ventricle and the aorta by a separate additional cannula. The outlet cannula can cause complications and the possibility of clotting, thrombosis and stroke. ECMO requires multiple catheter insertions and blood trauma can result in bleeding. In addition, ECMO does not relieve the left ventricle.
Zwischenberger’s and Wang’s new patented apparatus, the Apex-to-Aorta Cannula Assembly, is designed to be less invasive and to provide rapid cardiac and pulmonary support.
The single cannula assembly has an inner and outer catheter that is inserted into the left ventricle. The inner cannula portion is guided past the aortic valve and into the aorta without requiring a secondary incision for cannula insertion. The Wang/Zwisch device has a motor and impeller that can be inserted directly into the heart through the left ventricle. This provides a pump within the heart, via the single insertion, that can reduce blood clots and lessen complications. More importantly, the pump serves to relieve the burden on the heart, provide rest to the left ventricle, and efficiently circulate blood to the rest of the body.
While the Apex-to-Aorta Cannula Assembly is patented, it has not yet been manufactured and much refinement remains to be accomplished in the labs at UK. Nevertheless, we congratulate Drs. Zwischenberger and Wang for their foresight and ingenuity. Kudos and Congrats!