Patent Application
20050246000
n/a
n/a
The present invention relates to a medical method and apparatus for treating swelling of the brain.
In head injuries and stroke, neurological damage generally is caused by swelling of the brain within the confined space of the skull. With increased swelling, the brain can no longer be contained in the cranium and thus shifts, with the brain stem possibly becoming twisted. Blood flow to the brain is impeded resulting in brain damage or death. In trauma cases, further complications can result from a badly contused brain tissue.
The traditional approach to dealing with brain swelling in trauma situations has been to medically manage the patient with various pharmaceuticals, remove brain tissue, or in some cases remove entire lobes of the brain, with certain brain damage resulting. However, in an attempt to spare brain tissue, a procedure has been developed to provide room for the brain to swell. This procedure, known as a decompressive craniectomy, is illustrated in
Although the decompressive craniectomy has the potential to save brain tissue, it is believed that patients would further benefit if swelling could be reduced and/or if the duration of the swollen state were reduced.
The present invention advantageously provides a method and system for reducing the extent and duration of brain swelling in a trauma or stroke victim, or patient otherwise requiring a decompressive craniectomy.
In an exemplary method, a medical procedure for inhibiting swelling of the brain include the steps of: performing a decompressive craniectomy to expose intracranial tissue and immediately relieve intracranial pressure; placing a cooling structure on the exposed intracranial tissue; and cooling the exposed intracranial tissue with the cooling structure.
A more complete understanding of the present invention, and the attendant advantages and features thereof, will be more readily understood by reference to the following detailed description when considered in conjunction with the accompanying drawings wherein:
The present invention includes a medical procedure for inhibiting swelling of the brain by locally cooling the brain. In an exemplary procedure, known medical techniques are used to remove a relatively large portion of the skull, such as in the decompressive craniectomy illustrated in
Having determined whether the brain is to be cooled directly or indirectly through the dura, a cooling structure as described below is placed directly on the exposed intracranial tissue. The cooling structure is then cooled to a predetermined temperature below normal body temperature (98.6 degrees F.), but above freezing (32 degrees F.), thereby cooling the intracranial tissue to a temperature above freezing, but below body temperature. The cooling structure is left in place on the intracranial tissues for a selected period of time or until tissue swelling has subsided. To the extent possible, the cooling structure is dimensioned so as to cover and in be in contact with substantially as much of the exposed intracranial tissue as possible.
Turning now to
Although the source of coolant 18 can be a reservoir from which cooling fluid is expelled to be collected elsewhere or discarded, in view of the expected long duration of the above described treatment, a looped or closed system is believed to be desirable, wherein the cooling fluid is continuously recirculated between the source of coolant and the cooling structure. More particularly, the source of coolant 18 can include a heat exchanger, a pump, and a control mechanism. Temperature, pressure and flow sensors are distributed through the system to provide information to the control mechanism which can, in response to sensor data, alter the performance of the system. The control mechanism can be set or programmed to maintain a specific temperature of the cooling structure and/or to monitor and maintain desired intracranial tissue at a selected temperature.
The cooling structure 18 can include a very flexible element, having a surface area greater than two square inches, that readily follows the curvature of the intracranial surface, through which the cooling fluid is circulated. Although the cooling structure 18 can be circular, square, rectangular, or irregular, the particular shape is not significant. Rather, the feature of importance is that the cooling structure 18 covers as much exposed tissue as possible and readily conforms to the tissue without injuring it or causing further trauma as shown in
Using a system, such as that described above, a medical procedure is possible for localized cooling of the brain, thereby avoiding systemic temperature reduction throughout the body that can lead to cardiac arrhythmia, immune suppression and coagulopathies.
It will be appreciated by persons skilled in the art that the present invention is not limited to what has been particularly shown and described herein above. In addition, unless mention was made above to the contrary, it should be noted that all of the accompanying drawings are not to scale. A variety of modifications and variations are possible in light of the above teachings without departing from the scope and spirit of the invention, which is limited only by the following claims.
