Patent Application
20060142782
This invention pertains in general to devices and procedures for medical care and pertains in particular to medical devices and techniques for brain surgery.
As shown in
A subdural hematoma is the accumulation of blood in the subdural space 114. Subdural hematomas typically result from traumatic head injuries that cause the rupture of blood vessels located within the meninges. One way of treating subdural hematomas is by evacuation using percutaneous drainage. Percutaneous catheter drainage has emerged as a less invasive technique for the treatment of chronic subdural hematomas, which may be performed at the patient's bedside. A catheter is inserted through a single burr hole 120 in the cranium 110 into the subdural space 114 and connected to a drainage bag (not shown). Using this technique, the subdural hematoma is drained slowly, over a period of days, allowing the brain 124 to gradually expand out toward the cranium 110 without creation of a new space, thereby reducing the risk of subdural hematoma recurrence.
In order to ensure that the catheter is properly positioned, a surgeon will typically use a guide wire to create a path into the subdural space 114. The surgeon first inserts the curved end of a J-shaped cannula through the burr hole 120 and into the subdural space 114. While holding the J-shaped cannula in place, the surgeon will then insert the guide wire through the cannula and into the subdural space 114. Once the guide wire is in place, the surgeon will remove the cannula by sliding it back along the length of the guide wire.
The equipment and the procedure described above present a great danger of injury to the brain. Specifically, guide wires are typically made of high tensile strength stainless steel. These stainless steel guide wires will not tolerate the strain of bending ninety degrees without plastically deforming and therefore retaining the curvature of the forced bend. The result of being forced to curve seventy to ninety degrees after entering the subdural space 114 through the J-shaped cannula causes the stainless steel guide wire to arc backward into the skull and may potentially cause undesired piercing trauma. Furthermore, a stainless steel guide wire which is forced to curve seventy to ninety degrees by the J-shaped cannula used to guide it, by the very nature of that force and the resultant friction between the stainless steel guide wire and the J-shaped cannula, resists the removal of the J-shaped cannula without the associated disturbance of the location of the stainless steel guide wire. Still further, the small diameter of the stainless steel guide wire may cause piercing trauma as it is inserted into the subdural space 114 even though rounded on its distal end.
Therefore, a need existed for an assembly and method for guiding insertion of a medical device, such as a guide wire, into the subdural space surrounding a brain. Preferably, the assembly will be dimensioned to allow its removal from the target area without disturbance of the location of the guide wire. Further preferably, the device would protect the brain from injury during insertion of the guide wire by directing the guide wire through the subdural space at an angle substantially tangent to the curvature of the brain.
An object of the present invention is to provide an assembly for guiding insertion of a medical device, such as a guide wire, into the brain's surrounding subdural space.
It is a further object of the present invention to provide an assembly that may be removed from the target area without disturbance of the location of the guide wire.
It is a further object of the present invention to provide an assembly that would protect the brain from injury during insertion of a guide wire by directing the guide wire through the subdural space at an angle substantially tangent to the curvature of the brain.
In accordance with one embodiment of the present invention, an assembly for guiding insertion of a medical device into a target area of a vertebrate is disclosed. The assembly comprises: a first elongate member having a first end, a shaft portion coupled to and extending from the first end of the first elongate member, and a substantially C-shaped second end coupled to and extending from the shaft portion of the first elongate member and disposed opposite the first end of the first elongate member, the substantially C-shaped second end dimensioned to guide the medical device into the target area in a desired direction; and a second elongate member having a first end, a shaft portion defining a bore extending therethrough and the shaft portion being coupled to and extending from the first end of the second elongate member and being dimensioned to permit a medical device to be inserted therethrough, and a second end coupled to and extending from the shaft portion of the second elongate member and disposed opposite the first end of the second elongate member, the second end of the second elongate member dimensioned to be removably coupled to the substantially C-shaped second end of the first elongate member.
In accordance with another embodiment of the present invention, an assembly for guiding insertion of a medical device into a subdural space is disclosed. The assembly comprises: a first elongate member having a first end, a shaft portion coupled to and extending from the first end of the first elongate member, a neck portion coupled to and extending from the shaft portion of the first elongate member, a substantially C-shaped second end coupled to and extending from the neck portion of the first elongate member and disposed opposite the first end of the first elongate member, the substantially C-shaped second end dimensioned to guide the medical device into the subdural space in a direction substantially tangent to a curvature of a brain, and a groove defined by and extending along the substantially C-shaped second end of the first elongate member and dimensioned to permit a medical device to pass therethrough; a second elongate member having a first end, a shaft portion defining a bore extending therethrough and the shaft portion being coupled to and extending from the first end of the second elongate member and being dimensioned to permit a medical device to be inserted therethrough, a substantially half-cylindrical neck portion coupled to and extending from the shaft portion of the second elongate member, a substantially flat second end coupled to and extending from the substantially half-cylindrical neck portion of the second elongate member and disposed opposite the first end of the second elongate member, the substantially flat second end providing a roof for enclosing at least a portion of the groove defined by and extending along the substantially C-shaped second end of the first elongate member, and at least two clasps coupled to and curving inwardly from the roof of the substantially flat second end of the second elongate member, the clasps being dimensioned to engage the substantially C-shaped second end of the first elongate member; and a housing, defining a bore extending therethrough proximate a first side of the housing, the bore dimensioned to receive the shaft portion of the first elongate member and a groove extending along a second side of the housing, the groove dimensioned to snap-fit the shaft portion of the second elongate member wherein the housing being dimensioned to maintain the second elongate member at an approximately forty-five degree angle to the first elongate member.
In accordance with another embodiment of the present invention, an assembly for guiding insertion of a medical device into a subdural space is disclosed. The assembly comprises an elongate member having a first end, a shaft portion defining a bore extending therethrough and the shaft portion being coupled to and extending from the first end and being dimensioned to permit a medical device to be inserted therethrough, a neck portion coupled to and extending from the shaft portion, and a substantially C-shaped second end coupled to and extending from the neck portion and disposed opposite the first end, the substantially C-shaped second end dimensioned to guide the medical device into the subdural space in a direction substantially tangent to a curvature of a brain.
In accordance with yet another embodiment of the present invention, a method for guiding insertion of a medical device into a target area of a vertebrate is disclosed. The method comprises the steps of: providing an assembly having a first elongate member, a second elongate member, and a housing dimensioned to maintain the second elongate member at an approximately forty-five degree angle to the first elongate member; inserting a substantially C-shaped end of the first elongate member into the target area of the vertebrate; guiding the medical device substantially downwardly through a bore extending through the second elongate member; guiding the medical device along a groove defined by the substantially C-shaped end of the first elongate member; and inserting the medical device into the target area of the vertebrate in the desired direction.
In accordance with still another embodiment of the present invention, a method for guiding insertion of a super elastic nitinol guide wire into a subdural space is disclosed. The method comprises the steps of: providing an assembly having a first elongate member, a second elongate member, and a housing dimensioned to maintain the second elongate member at an approximately forty-five degree angle to the first elongate member; inserting a substantially C-shaped end of the first elongate member into the subdural space; guiding the super elastic nitinol guide wire substantially downwardly through a bore extending through the second elongate member; guiding the super elastic nitinol guide wire along a groove defined by the substantially C-shaped end of the first elongate member; inserting the super elastic nitinol guide wire into the subdural space in the direction substantially tangent to the curvature of the brain; detaching the second elongate member from the housing; sliding the second elongate member away from the target area while the super elastic nitinol guide wire passing therethrough while at the same time the super elastic nitinol guide wire maintaining its position within the subdural space; and removing the substantially C-shaped end of the first elongate member from the subdural space while at the same time the super elastic nitinol guide wire maintaining its position within the subdural space.
In accordance with still another embodiment of the present invention, a method for guiding insertion of a super elastic nitinol guide wire into a subdural space is disclosed. The method comprises the steps of: providing an elongate member having a first end, a shaft portion defining a bore extending therethrough and being dimensioned to permit a medical device to be inserted therethrough, a neck portion, and a substantially C-shaped second end defining a groove extending along the substantially C-shaped second end and dimensioned to permit a medical device to pass therethrough; inserting the substantially C-shaped second end into the subdural space; guiding the super elastic nitinol guide wire substantially downwardly through the bore; guiding the super elastic nitinol guide wire along the groove; inserting the super elastic nitinol guide wire into the subdural space in a direction substantially tangent to a curvature of a brain; removing the substantially C-shaped second end from the target area while the super elastic nitinol guide wire passing therethrough while at the same time the super elastic nitinol guide wire maintaining its position within the subdural space; and sliding the elongate member away from the target area while the super elastic nitinol guide wire passing therethrough while at the same time the super elastic nitinol guide wire maintaining its position within the subdural space.
The foregoing and other objects, features, and advantages of the invention will be apparent from the following, more particular, description of the preferred embodiments of the invention, as illustrated in the accompanying drawings.
The novel features believed characteristic of the invention are set forth in the appended claims. The invention will best be understood by reference to the following detailed description of illustrated embodiments when read in conjunction with the accompanying drawings, wherein like reference numerals and symbols represent like elements.
Referring to
As shown in
The first elongate member 18 preferably comprises a first end 20 (see
The second elongate member 30 (shown in
Referring to
Referring to
Referring now to
Referring now to
Once the guide wire 12 is in place, the surgeon will then detach the second elongate member 30 from the groove 54 (or the bore 52) extending along the second side 50 of the housing 46. After detaching the second elongate member 30, the surgeon will then slide it away while the guide wire 12 passes therethrough, while at the same time ensuring that the guide wire 12 maintains its position within the subdural space 114. And finally, the surgeon will remove the substantially C-shaped second end 26 of the first elongate member 18 from the subdural space 114, while at the same time ensuring that the guide wire 12 maintains its position within the subdural space 114. After the assembly 10a has been completely removed, the surgeon will then insert a catheter 56 into the subdural space 114. As shown in
If using the assembly 10b of
While the invention has been particularly shown and described with reference to preferred embodiments thereof, it will be understood by those skilled in the art that the foregoing and other changes in form and details may be made therein without departing from the spirit and scope of the invention. For example, although it is preferred that the medical device 14 being inserted through the assembly is a guide wire 12, it should be further understood that substantial benefit may be derived from using the assembly to aid the insertion of a different medical device 14, such as a lead, a catheter, a stent, a filter, a needle, a guide pin, or a cannula. It should be further understood that although it is preferred that the guide wire be made of superelastic nitinol, substantial benefit may be obtained from a guide wire being made of an alternate material, so long as the guide wire may easily maintain its position in the subdural space during removal of the assembly.
