The ability of cells to survive oxygen deprivation after a cardiac arrest, heart attack, or stroke can be significantly improved by rapidly cooling the affected organs. Argonne National Laboratory (ANL) engineers (Ken Kasza, lead engineer), working with the University of Chicago Medical School have developed an easy-to-use ice slurry, along with the associated slurry generation methods, delivery equipment, and medical use protocols that can more effectively cool organs than current technologies.

Poor Fluidity	Good Fluidity
Chemical and thermal smoothing of globular ice particles yields dramatic improvements in ice slurry loading, fluidity, and storability.

The ice slurry coolants are liquids that contain micron-sized ice particles suspended in salt water. The ice particles make up close to 60% of the mixture by weight. In order to be effective, the ice particles must be globular and very smooth so the slurry can be pumped through narrow delivery tubes without clogging. Because the ice slurries can be delivered using typical medical tubes, the use of the technology is uncomplicated, relatively noninvasive, and easily monitored and controlled. In addition, because the slurry can be placed inside the body, the body's natural insulation assists with the cooling process, resulting in quicker and more efficient cooling than other methods. For example, using traditional methods, cooling an adult's brain by 4°C may take more than four hours; using the ice slurry, an adult's brain can be cooled by 4°C in less than 15 minutes. This capability will markedly change emergency medical practices and allow better patient outcomes for emergency events such as cardiac arrest and stroke, where rapid cooling will protect the brain for period of time.

The ice slurry technology will also be useful for laparoscopic (so called "keyhole") surgery. Laparoscopic surgery is often preferred due to much smaller incisions, shorter hospital stays and reduced recovery times. By providing a minimally invasive method of cooling target organs, the surgical window for laparoscopic surgery can be greatly extended, allowing more complicated operations that currently must be performed by open surgery. In conventional open surgery through large incisions, cooling is implemented by the surgeon hand packing crushed ice around the readily accessible organ. For example, the typical laparoscopic surgical window for a partial nephrectomy (removal of a portion of the kidney) is 30 minutes. With ice slurry cooling, this surgical window can be extended to at least two hours by pumping slurry through a small tube to coat the organ remotely via endoscope viewing, thereby allowing much more complex surgeries to be performed laparoscopically.

A close collaboration between ANL and the University of Chicago Medical School has evolved into the formation of Cold Core Therapeutics, LLC, to further develop and commercialize the ice slurry technology. The research and development of the ice slurry also led to development and use of three-dimensional computational modeling of organs to aid doctors with identifying and evaluating organ cooling strategies. Computational modeling has proven to be a very valuable tool in this research, with even broader application to many other diverse medical treatments. The computational modeling performed for this project forms the basis for a proposed NIH Center for Developing Computational Thermal, Structural, and Fluid Models of Organs/Organ Networks that would be a partnership between five institutions: ANL; the University of Chicago Medical School; University of Kansas Medical Center; ABAQUS Central, Inc.; and Flowmaster USA, Inc.

Quantification of the effectiveness, repeatability, and development of therapeutic cooling for cardiac arrest using the ice slurry technology is being conducted through multiple animal experiments funded by a $4 million, 5-year National Institutes of Health (NIH) grant. Additionally, NIH funding is being sought for development of laparoscopic procedures utilizing the ice slurry. Food and Drug Administration approval of laparoscopic procedures utilizing the ice slurry is anticipated in 2008; similar approvals for cardiac arrest due to greater medical complexity may take an additional two to three years of study. The successful collaboration between ANL and the University of Chicago was recognized with the FLC Midwest Region 2006 Partnership Award.