In general, progress to develop an artificial lung lags years behind that of the artificial kidney, liver and heart. Together with bioengineer William J. Federspiel of Pitt's surgery department, Hattler has created an intravenous respiratory assist device that is easily inserted through a vein in the leg and positioned into the vena cava, the major vein returning blood to the heart. It consists of hollow fiber membranes that introduce oxygen into and remove carbon dioxide from the body. Key to its design, and a distinction from the device that failed, is a central balloon within the fibers that can inflate and deflate at a rate of 300 beats per minute to move the fibers and mix the blood. This allows for more efficient oxygenation of blood and removal of carbon dioxide.
Respiration takes place even though the lungs are severely injured and functioning poorly.
The surface area of two lungs is about the size of a tennis court. The Hattler Catheter has a surface area equivalent to an 8 x 11inch sheet of paper and can perform about 50 percent of the gas exchange requirements of an adult. Because the Hattler Catheter is intended to temporarily take over the function of the lungs, it could meet a need for patients with acute respiratory failure, such as those with emphysema or those who have suffered trauma to the lungs. Currently, the standard of care is the use of extracorporeal membrane oxygenators, which are bulky and expensive units that can cause life-threatening complications and death in more than half of those who are treated with them. The device is not envisioned for prolonged support, say as a bridge to transplant or as a total replacement of the lungs.