Systems and Methods for Cutting a Hole in Bony Matter for Implantation of a Medical Device
Publication Date: 2002-Sep-20
The IP.com Prior Art Database
A template-guidance system is secured to an even or uneven bony surface. A surgical tool, such as a drill, possibly with tool attachments, such as a shield, follows a template-guide of the template-guidance system to cut a precisely shaped hole without damaging underlying tissue. The bone is removed, exposing the precisely shaped hole for placement of a correspondingly shaped medical device. The disclosed template-guidance systems also allow for placement of slanted holes in the bone to facilitate suturing around the base of the hole. The template-guidance systems also provide a slot for creating a groove in the bone for a neurostimulation lead or catheter exit. The template-guidance systems also provides a deformable member(s) (or are themselves deformable) for use on uneven surfaces.
for Implantation of a Medical Device
Background & Summary
� � � � � � � � � � � � � � � � � � � � � � � Implantable medical devices such as stimulators, shunts, pumps, and monitors are often implanted in a bony area of the body.� For example, portions of some cochlear implants are implanted in the temporal bone of the skull.� To ensure that an implantable device is secured in a bony member, such as the skull, a precise hole that is dimensionally similar to the implantable device is desired.� Further, precise and dimensionally similar holes are more physically and aesthetically satisfying for patients.� Unfortunately, there is no reliable or cost effective system currently on the market that allows for such an operation.
� � � � � � � � � � � � � � � � � � � � � � � U.S. Patent Nos. 4,941,466; 4,920,958; 4,901,711; and 4,823,780 disclose methods, systems, and apparatuses for drilling through bony material.� However, none of the methods, systems, or apparatuses teaches cutting a variety of precisely shaped holes that fit a variety of correspondingly shaped implantable medical devices by means of a guiding device that is anchored to the bony matter that is cut.
� � � � � � � � � � � � � � � � � � � � � � � The present invention allows for cutting a precisely shaped hole in a bone for the purpose of fixation of an implantable device of corresponding precise shape in a bony member, such as the skull.� This is accomplished by a novel device that is capable of being attached to a regular or irregular bony surface, such as, but not limited to, the skull.� The device also creates a guide for a cutting tool, such as commercially available, high-speed router with or without an attached shield for protecting the underlying tissue against destruction.� The cutting tool does not have to be a commercially available drill, but the device may advantageously accommodate such.� A precise shape is any size and shape, regular or irregular, rounded or sharply angled, which is needed to house an implantable medical device of corresponding dimension.
Described herein is a template-guidance system 160 (see FIG. 1) for a router that allows for simultaneous cutting of a precisely shaped hole and guiding of a rotating cutter.� The template-guidance system 160 is secured to a bony surface, such as a skull, by fasteners, e.g. screws of preferably stainless steel or titanium material.�
In one embodiment discussed in detail presently, between a template-guide 300 and the bone is a deformable positioning member that levels the device and allows for firm placement of the device on an irregular bony surface, such as the skull.� In another embodiment of the present invention, adjustable legs or tabs 150 on a template-guide 300 can be retracted or extended in order to position and level the template-guide 300 on an irregular bony surface.� In another embodiment, the fasteners securing the template-guidanc...