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HetaCoolTM
STATUS: IND PREPARATION STAGE |
LOW TEMPERATURE BLOOD REPLACEMENT HYPOTHERMIC HEART AND BRAIN SURGERY |
PRODUCT DESCRIPTION
HetaCool is a modified formulation of Hextend specifically designed for use at low temperatures. Interruption of blood flow can be maintained only for short periods of time at normal body temperatures because many critical organs, particularly the brain, are quickly damaged by the resultant loss of oxygen. As a result, certain surgical procedures are performed at low temperatures because lower body temperature helps to minimize the chance of damage to the patient's organs by reducing the patient's metabolic rate, thereby decreasing the patient's needs during surgery for oxygen and nutrients which normally flow through the blood.
Current technology limits the degree to which surgeons can lower a patient's temperature and the amount of time the patient can be maintained at a low body temperature because blood, even when diluted, cannot be circulated through the body at near-freezing temperatures. As a result, surgeons face severe time constraints in performing surgical procedures requiring blood flow interruption, and those time limitations prevent surgeons from correcting certain cardiovascular abnormalities. In this regard, surgeons are already using a variety of other solutions to carry out certain limited procedures involving shorter term (up to nearly one hour) arrest of brain and heart function at temperatures between 15 and 20o C. However, BioTime is not aware of any fluid currently used in medical practice or any medically-approved protocol allowing operations which can completely replace all of a patient's blood at temperatures close to the ice point.
The Company is in the process of preparing an IND application to conduct clinical trials using HetaCool as a solution to replace all of a patient's circulating blood volume during profound hypothermic (carried out at near-freezing temperatures) surgical procedures, such as repair of the aortic arch, during which heart and brain activity could be arrested for 2 hours or more. HetaCool would be introduced into the patient's body during the cooling process. Once the patient's body temperature is nearly ice cold, and heart and brain function are temporarily arrested, the surgeon would perform the operation. During the surgery, HetaCool may be circulated throughout the body in place of blood, or the circulation may be arrested for a period of time if an interruption of fluid circulation is required. Upon completion of the surgery, the patient would be slowly warmed and blood would be transfused.
The Company believes that these low temperature bloodless surgical techniques could be developed for open heart and minimally invasive closed chest cardiovascular surgeries, and removal of tumors from the brain, head, neck or heart.
EARLY POSITIVE RESULTS
HetaCool has been used to completely replace the blood volume of hamsters, dogs and baboons at temperatures approaching freezing. Many of these animal subjects survived long term after hypothermic blood substitution with HetaCool. In these laboratory tests, the animals' blood was removed and they were chilled for one to more than four hours with deep body temperatures between 1oC and 10oC while chilled HetaCool was oxygenated and slowly circulated.
MARKET SIZE
If HetaCool can be used safely and effectively in low temperature surgery, the market size for the product could be substantial given the large numbers of potential patients and the large volume (up to fifty liters) of solution that would be used in each treatment.
MULTI-ORGAN PRESERVATION
BioTime is also developing HetaCool for use as a multi-organ preservation solution. When used as an organ preservation solution, HetaCool would be perfused into the donor's body while the body is chilled, thereby eliminating an undesirable condition called "warm ischemia," caused when an organ is warm while its blood supply is interrupted. The use of HetaCool in conjunction with the chilling of the body should help to slow down the process of organ deterioration by a number of hours so that a surgeon can remove all organs for donation and transplant. The Company's current estimates are that each such preservation procedure could require as much as 50 to 100 liters of HetaCool.
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BioTime, Inc.
1301 Harbor Bay Pkwy
Alameda, CA 94502
tel: 510.521.3390
fax: 510.521.3389
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© 2007 BioTime, Inc. | All Rights Reserved.
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The anesthetized patient is wrapped in a cooling blanket and connected to a cardiopulmonary bypass circuit. He is cooled, and his blood is completely replaced with BioTime's ice cold blood substitute.
Chilling is then continued until he is near freezing. He is maintained ice cold and bloodless while surgery on his heart or brain, requiring complete cessation of blood flow, is completed.
He is then rewarmed, his blood replaced, and he is revived.