Spinal cord stimulators have been used to treat patients who experience chronic and severe back pain. A spinal cord stimulator is a device that stimulates the spinal cord by tiny electrical impulses from small electrical wires placed on the spinal cord itself. These electrical impulses interrupt nerve conduction (i.e. the conduction of pain signals) to the brain.
As shown in
Within the vertebral canal 112, the spinal cord 122 is surrounded and protected by the dura mater 124 (see
The method of insertion of a spinal cord stimulator depends upon its width. The width of existing spinal cord stimulators varies between 1 mm and 8 mm and the height varies between 1 mm and 3 mm. Smaller, narrower leads and cannulas are sometimes inserted into the epidural space by placement of a Tuohy needle, which has a curved tip, into the epidural space. The curve of the Tuohy needle tip guides the lead into the epidural space, parallel to the spinal cord, so as to avoid injury to the spinal cord 122 by the lead during insertion.
For wider spinal cord stimulators 200 (see
Tubular retractors 300 (see
Although tubular retractors 300 offer a minimally invasive exposure of the epidural space 126, the length of the tubular retractor 300 (typically between 3 cm and 9 cm) makes it difficult for the surgeon to manually guide wider spinal cord stimulators 200 into the epidural space 126. Additionally, the paddle probe has too large of an angle to fit conveniently through a tubular retractor 300.
Therefore, a need existed for a device and method for guiding insertion of a medical device into the spinal epidural space of a vertebral column. Preferably, the device will be dimensioned to guide insertion of a medical device through a tubular retractor. Further preferably, the device may be used by surgeons to dissect the dura mater away from the lamina. Still further preferably, the device would protect the spinal cord from injury during insertion of a spinal cord stimulator by directing the spinal cord stimulator through the epidural space at an angle substantially parallel to the spinal cord.
An object of the present invention is to provide a device for guiding insertion of a medical device into the spinal epidural space of the vertebral column.
It is a further object of the present invention to provide a device for guiding insertion of a medical device through a tubular retractor.
It is a further object of the present invention to provide a device that may be used to dissect the dura mater away from the lamina of the vertebra.
It a still further object of the present invention to provide a device that will protect the spinal cord from injury during insertion of a spinal cord stimulator by guiding the spinal cord stimulator through the epidural space at an angle substantially parallel to the spinal cord.
In accordance with one embodiment of the present invention, a device for guiding insertion of a medical device into a target area of a vertebrate is disclosed, comprising a substantially J-shaped angled probe comprising a first end, a shaft portion coupled to and extending from the first end, a substantially curved neck portion coupled to and extending at an angle from the shaft portion, the shaft portion dimensioned to guide a medical device from the first end of the angled probe through the substantially curved neck portion, a second end coupled to the substantially curved neck portion and disposed opposite the first end, the second end dimensioned to guide the medical device to the target area of the vertebrate at an angle substantially perpendicular to the shaft portion of the angled probe, and at least one side rail coupled to and extending at an angle substantially perpendicular from at least one of the neck portion and the second end.
In accordance with another embodiment of the present invention, a device for guiding insertion of a medical device into a target area of a vertebrate is disclosed, comprising a substantially J-shaped angled probe comprising a first end, a shaft portion coupled to and extending from the first end, a substantially curved neck portion coupled to and extending at an angle from the shaft portion, the shaft portion dimensioned to guide a medical device from the first end of the angled probe through the substantially curved neck portion, a second end coupled to the substantially curved neck portion and disposed opposite the first end, the second end dimensioned to guide the medical device to the target area of the vertebrate at an angle substantially perpendicular to the shaft portion of the angled probe, and a roof portion coupled to and enclosing at least a portion of at least one of the substantially curved neck portion and the second end.
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, comprising, in combination, the steps of providing a substantially J-shaped angled probe having a first end, a shaft portion coupled to and extending from the first end, a substantially curved neck portion coupled to and extending at an angle from the shaft portion, a second end coupled to the substantially curved neck portion and disposed opposite the first end, and at least one side rail coupled to and extending at an angle substantially perpendicular from at least one of the neck portion and the second end, inserting the angled probe into the target area of the vertebrate, guiding a medical device substantially downwardly along the angled probe, and inserting the medical device into the target area of the vertebrate at an angle substantially parallel to the target area.
In accordance with still another embodiment of the present invention, a method for guiding insertion of a medical device into a target area of a vertebrate is disclosed, comprising, in combination, the steps of providing a substantially J-shaped angled probe having a first end, a shaft portion coupled to and extending from the first end, a substantially curved neck portion coupled to and extending at an angle from the shaft portion, a second end coupled to the substantially curved neck portion and disposed opposite the first end, and a roof portion coupled to and enclosing at least a portion of at least one of the substantially curved neck portion and the second end, inserting the angled probe into the target area of the vertebrate, guiding the medical device substantially downwardly along the angled probe between the roof portion and at least a portion of at least one of the substantially curved neck portion and the second end, and inserting the medical device into the target area of the vertebrate at an angle substantially parallel to the target area.
In accordance with still another embodiment of the present invention, a method for guiding insertion of a spinal cord stimulator into a spinal epidural space through a tubular retractor is disclosed, comprising, in combination, the steps of providing a tubular retractor, positioning the tubular retractor to allow access to the spinal epidural space, providing a substantially J-shaped angled probe having a first end, a shaft portion coupled to and extending from the first end, a substantially curved neck portion coupled to and extending at an angle from the shaft portion, a second end coupled to the substantially curved neck portion and disposed opposite the first end, and at least one side rail coupled to and extending at an angle substantially perpendicular from at least one of the neck portion and the second end, inserting the angled probe through an aperture defined by the tubular retractor, penetrating the spinal epidural space with the second end of the angled probe, dissecting at least a portion of the dura mater from the lamina with the second end of the angled probe, providing a spinal cord stimulator, and dissecting the dura mater from the remaining lamina while the spinal cord stimulator being guided substantially downwardly along the angled probe into the spinal epidural space at an angle substantially parallel to a spinal cord.
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.
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Preferably, the angled probe 10 is dimensioned to be used with a spinal cord stimulator 200 having a length of between 4 cm and 6 cm, a width of between 1 mm and 8 mm, and a height of between 1 mm and 3 mm. It should be clearly understood, however, that substantial benefit may be derived from an angled probe 10 that is dimensioned to be used with a spinal cord stimulator 200 having a length, width, or height that deviates, even substantially, from the length, width, and height of the preferred spinal cord stimulator 200. And although it is preferred that the angled probe 10 be dimensioned to guide insertion of the spinal cord stimulator 200 through a tubular retractor 300 having a length of between 3 cm and 10 cm it should be clearly understood that substantial benefit may be derived from the angled probe 10 being dimensioned to be used with a tubular retractor 300 having a length that deviates, even substantially, from the length of the preferred tubular retractor 300.
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While, in the various embodiments described above, the angled probe 10 is shown having various combinations of side rails 22 of varying dimensions, side grooves 12 of varying dimensions, and roof portions 24 of varying dimensions, it should be clearly understood that substantial benefit could be derived from alternative configurations of the angled probe 10 in which other combinations not described here are used. For example, substantial benefit may be derived from an angled probe 10 having both side grooves 12 as well as a roof portion 24.
In order to implant a spinal cord stimulator 200, a laminotomy or a limited laminectomy is performed. Then the angled probe 10 is passed through the tubular retractor 300 and inserted into the spinal epidural space 126 of the vertebral canal 112. The angled probe 10 is used to dissect a portion of the dura mater 124 away from the lamina 120. Then, the spinal cord stimulator 200 is used to dissect the dura mater 124 from the remaining lamina 120 distal to the site of the laminotomy or laminectomy, while the spinal cord stimulator 200 is guided substantially downwardly along the angled probe 10 and into the spinal epidural space 126 at an angle substantially parallel to the spinal cord 122.
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 the angled probe is intended to guide insertion of medical devices into the epidural space of a vertebral column, it should be clearly understood that substantial benefit may be derived from its use in guiding insertion of medical devices into alternate target areas of the body.
This application claims priority to a corresponding provisional application U.S. Ser. No. 60/506,446, filed Sep. 26, 2003 in the name of the applicant of this application.
Number | Date | Country | |
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60506446 | Sep 2003 | US |