Device and method for manipulating intervertebral tissue

#This invention relates to surgical devices and, more particularly, to devices used to loosen tissue for removal in a surgical patient.

#The spinal column acts as a major structural support. Various mechanisms, however, affect the ability of intervertebral disks to provide the requisite stability and support. For example, the normal aging process tends to weaken the bones and tissues associated with the spinal column increasing the risk of spinal injuries. Additionally, sudden movements may cause a disk to rupture or herniate. A herniation of the disk is primarily a problem when the nucleus pulposus protrudes or ruptures into the spinal canal placing pressure on nerves which in turn causes spasms, tingling, numbness, and/or pain in one or more parts of the body, depending on the nerves involved. Further deterioration of the disk can cause the damaged disk to lose height and to produce bone spurs. These mechanisms may result in a narrowing of the spinal canal and foramen, thereby causing undesired pressure on the nerves emanating from the spinal cord.

#Treatments of spinal cord conditions include various procedures which involve the removal of all or a portion of a spinal component. Such procedures may include the injection of an enzyme into an affected disk to dissolve tissues. The enzymes typically used in this procedure are protein-digesting enzymes which must be carefully placed with respect to the spinal defect to avoid inadvertent dissolution of spinal tissue.

#FIG. 1 shows a schematic view of an intervertebral tissue removal system with a single abrading member on a node of an expandable member wherein aspiration fluid is fed into an expansion media conduit through an inlet on a cannula to provide expansion media incorporating principles of the present invention;

#FIG. 2 shows a cross-sectional view of the flow path of aspiration fluid through the cannula, conduit and expandable member of FIG. 1;

#FIG. 3 shows a partial cross-sectional view of the cannula of FIG. 1 after puncturing a disc with the cannula in preparation for forming a cavity within the disc;

#FIG. 1 depicts an intervertebral tissue removal system 100 which includes a fluid reservoir 102, a cannula 104 and an expandable member 106. The fluid reservoir 102 is in fluid connection with the cannula 104 through a tube 108 which is connected to a fluid inlet 110. In this embodiment, the fluid reservoir 102 is configured to provide a liquid in the form of saline solution under pressure to the fluid inlet 110. The fluid may be pressurized in a number of acceptable ways such as using a gas to pressurize the fluid reservoir 102 or a pump that takes suction from the fluid reservoir 102. In alternative embodiments, the fluid may be in the form of a gas. In the embodiment of FIG. 1, however, the fluid is preferably a liquid.

#An outlet port 112 is located on the cannula 104. The outlet port 112 is in fluid connection with a drain 114 through a tube 116. In alternative embodiments, the drain 114 may be replaced with a vacuum collection system so as to provide a suction source for the cannula 104 through the outlet port 112.

#The expandable member 106 is connected to a conduit 118 which extends into an internal bore 120 of the cannula 104 as best seen in FIG. 2. The expandable member 106 may be formed integrally with the conduit 118. Alternatively, the expandable member 106 may be removably coupled to the conduit 118 to allow for the use of different expandable members with the intervertebral tissue removal system 100.