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...