Patent Application
20060015160
n/a
n/a
The present invention relates to a medical method and apparatus for treating swelling of the spinal cord and related nerve tissue and providing neuroprotection to such tissues.
In back injuries, neurological damage to the spinal cord, the tissue that surrounds it, and nerves that join the spinal cord can be caused by tissue swelling within the confined space of spinal canal that is defined by the vertebrae. With increased swelling, the pressure of the cerebrospinal fluid increases and spinal tissue impinges upon the hard bone of the vertebrae and where spaces exist, the injured tissue presses outward from its normal containment in the longitudinal passage defined by the spinal canal. The impingement of the soft nerve tissue against the hard bone can result in temporary or permanent nerve damage and possible paralysis or functional impairment of portions of the body or its organs.
One approach to dealing with spinal cord and associated nerve swelling, known as a laminectomy (open decompression), includes the removal of a small portion of the vertebral bone over the nerve root and/or disc material from under the nerve root to give the nerve root more space and a better healing environment.
Although the laminectomy 1 can be beneficial for certain conditions, it is believed that patients would further benefit by techniques and apparatus that reduce tissue swelling and/or reduce the duration of the inflamed condition.
The present invention advantageously provides a method and system for reducing the extent and duration of swelling of a spinal cord and related tissues and providing neuroprotection by cooling.
In an exemplary method, a medical procedure is provided for inhibiting swelling or inflammation of spinal tissue and/or providing neuroprotection. The method includes the step of subdermally (locally, beneath the skin), epidurally, or subdurally cooling spinal tissue. Such cooling can be effected by exposing spinal tissue, placing a cooling structure on the exposed spinal tissue, and cooling the exposed spinal tissue with the cooling structure to below body temperature for an extended period of time. Alternatively, a fluid below body temperature can be circulated through the spinal canal. Exemplary fluids include cerebrospinal fluid and non-bodily fluids such as saline.
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 cerebrospinal tissue swelling, decreasing tissue inflammations, and reducing cerebrospinal fluid pressure by cooling tissue or cerebrospinal fluid directly and/or by cooling cerebrospinal fluid to cool tissue indirectly. In addition, cooling tissue also has the effect of providing neuroprotection to tissues as the reduction of temperature has the effect of lowering cellular metabolism and reducing chemical reactions in damaged or compromised tissue.
In an exemplary procedure, known medical techniques are used to retract skin and muscle and to expose and remove vertebral bone, thereby providing access to the spinal canal and spinal tissue. As shown in
Having determined whether the spinal cord is to be cooled directly or indirectly through the dura, a cooling structure as described below is placed directly on the exposed 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 tissue to a temperature above freezing, but below body temperature. The cooling structure is left in place on the tissue 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 all of the exposed tissue.
Turning now to
Although the source of coolant 22 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 22 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 tissue at a selected temperature.
The cooling structure 24 can include a very flexible element, having a surface area that readily follows the curvature of the tissue surface, through which the cooling fluid is circulated. Although the cooling structure 24 can be circular, square, rectangular, or irregular, the particular shape is not significant. Rather, the feature of importance is that the cooling structure 24 covers as much exposed tissue as possible and readily conforms to the tissue without injuring it or causing further trauma. Exemplary materials suitable for the cooling structure 24 include rubber, silicone, flexible polymers and other bio-compatible materials known in the art.
In an exemplary embodiment, as shown in
Referring now to
Whereas the medical procedure illustrated in
In an alternative procedure to that illustrated in
Although the cooling effect described above with respect to
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.
