Patent Application
20100023065
The present invention relates generally to an apparatus for accessing bone or tissue structures and, more particularly, to an access assembly that incorporates a radiopaque alignment element adapted to aid in the placement of a cannula within a selected body structure.
A number of apparatus have been developed for accessing target areas of bone or tissue within a patient. Procedures such as vertebroplasty and kyphoplasty require the precise insertion and placement of an access device such as a cannula into a target area of bone to achieve access to an implantation site. In vertebroplasty, cancellous bone of an injured vertebra may then be supplemented with “bone cement,” e.g., polymethylmethacrylate (PMMA) or another material, in order to provide for stabilization of the vertebral body. In kyphoplastly, an expandable device such as a balloon is inserted into the interior of the vertebra and expanded. Following removal of the expandable device, the resulting void is typically filled with bone cement to promote stabilization of the vertebral body. Vertebroplasty and kyphoplasty are desirable from the standpoint that it is minimally invasive as compared to a conventional procedures requiring surgically exposing a tissue site that is to be supplemented with bone cement.
Several procedures are known for accessing a desired site in the cancellous bone of a vertebral body, or substantially any other cancellous bone, to deliver an expandable device and/or bone cement or another suitable hard tissue implant material to stabilize, or build up, a target site as taught by U.S. Pat. No. 6,280,456, U.S. Pat. No. 6,248,110, U.S. Pat. No. 5,108,404, and U.S. Pat. No. 4,969,888, which are each incorporated herein by reference.
To gain access to a hard tissue implantation site, as described in U.S. Pat. Nos. 6,019,776 and 6,933,411, which are each incorporated herein by reference, a straight needle or cannula in combination with a stylet may be employed. As discussed therein, a stylet incorporating self-tapping threads may be utilized to penetrate the cortical bone of the vertebra. Once access is achieved and the stylet is removed from the cannula, bone cement may be delivered through the cannula for the purpose of stabilizing the hard tissue implantation site.
Many access cannula devices incorporate a T-grip handle; however, alternate handle types are also available. For example, Clear-View® needles, manufactured and sold by the assignee, incorporate a barrel-shaped or cylindrical handle instead of a traditional T-grip type handle. The barrel handle of the Clear-View needle provides various advantages including presenting a so-called “bull's eye” image when viewed fluoroscopically. When viewed along the longitudinal axis of the cannula assembly, the outer wall and the interior interlocking assembly of the barrel-shaped handle have sufficient material thickness and radiopaque properties to appear as concentric circles when viewed under a fluoroscope and still allow visualization of the cannula and the target body structure. The concentric circles or “bull's eye” may then be used to gauge the alignment of the cannula with a target body structure. However, the size of barrel shaped handles may present problems in procedures that require the placement of multiple cannulas in a small area or closely juxtaposed, such as a vertebroplasty procedure requiring the bipedicular access of a vertebral body.
Therefore a need has arisen for an improved system and method for accessing a bone structure.
A further need has arisen for an improved system for showing the relative alignment of an access device and a radiographic viewing device.
The present disclosure presents an improved access assembly for use during a medical procedure including accessing a selected bone structure or other target tissue, and includes a cannula and stylet with an alignment guide removably attached to the cannula. The alignment guide preferably shows the relative alignment between the access assembly and the viewing axis of an imaging system when viewed fluoroscopically and/or radiographically, thereby making placement of the access assembly more accurate. Once a desired alignment of the access assembly is achieved, the access assembly may then be advanced further towards the target tissue until a desired placement is achieved.
In one aspect, an access assembly is disclosed including a cannula and an alignment guide. The cannula is adapted for percutaneously accessing a target tissue within a patient and includes a tubular elongate body and a handle. The tubular elongate body has a distal end, a proximal end, an outer surface and an inner luminal surface. The alignment guide includes an attachment portion and at least one radiopaque alignment indicator. The attachment portion of the alignment guide is adapted to removably attach to a portion of the outer surface of the tubular elongate body.
In another aspect, an access assembly is disclosed including a cannula and an alignment guide. The cannula is adapted for percutaneously accessing a target tissue within a patient and includes a tubular elongate body and a handle. The tubular elongate body has a distal end, a proximal end, an outer surface and an inner luminal surface. The alignment guide has an attachment portion and a radiopaque body. The attachment portion removably attaches to a portion of the outer surface of the tubular elongate body and the radiopaque body provides a visual reference of the alignment of the elongate body in relation to an axis of viewing of a radiographic device when viewed radiographically.
In another aspect a cannula for percutaneously accessing a target tissue within a patient is disclosed and includes a tubular elongate body and a handle. The tubular elongate body has a distal end, a proximal end, an outer surface and an inner luminal surface. The handle includes a first surface and a second surface separated by a thickness, where the first surface define a first plane and the second surface defines a second plane, and the first plane and second plane are substantially parallel. A first radiopaque landmark is disposed on the first surface and a second radiopaque landmark is disposed on the second surface.
In yet another aspect, a forceps assembly is adapted for grasping a tubular elongate body of a cannula. The forceps assembly includes a first member in pivotable connection with a second member, with each member having a proximal handle end and a distal grasping end. The distal grasping end of the first member and second member are pivotable between an open position and a closed position. The first member distal end includes a first grasping surface and the second member distal end having a second grasping surface, the first grasping surface and the second grasping surface are formed to grasp a portion of the tubular elongate body of the cannula in the closed position. A first radiopaque alignment indicator extends from a portion of the distal end of the first member and a second radiopaque alignment indicator extends from a portion on the distal end of the second member, such that the first radiopaque alignment indicator and the second radiopaque alignment indicator provide a visual reference of the alignment of the elongate body in relation to a target tissue when held therebetween in the closed position and viewed fluoroscopically.
In yet another aspect, an alignment guide for removably attaching to an elongate body includes an attachment portion and at least one alignment indicator. The attachment portion is adapted to removably attach to a portion of the outer surface of the elongate body and the radiopaque alignment indicator is adapted to provide a visual indication of the alignment of the cannula when viewed radiographically.
In still yet another aspect, a method of performing a medical procedure on a body is disclosed. The method includes providing a cannula assembly including a cannula adapted for percutaneously accessing a target tissue within a patient and an alignment guided. The cannula has a tubular elongate body and a handle; the tubular elongate body has a distal end, a proximal end, an outer surface and an inner luminal surface. The alignment guide has an attachment portion and at least one radiopaque alignment indicator, the attachment portion adapted to removably attach to a portion of the outer surface of the tubular elongate body. The method also includes attaching the alignment guide to a portion of the outer surface of the tubular elongate body and partially penetrating the body with the cannula. The method further includes aligning the cannula assembly with respect to a target tissue by viewing the cannula under fluoroscopy, advancing the assembled cannula system to access the target tissue, and treating the target tissue.
The present disclosure includes a number of important technical advantages. One technical advantage is that the alignment guide and alignment landmarks provide a clear indication of the relative alignment of the access assembly with respect to the viewing axis of a radiographic or similar viewing device. Another important advantage (in some embodiments) is that the alignment guide is removable and can be removed from the cannula following needle placement. This allow for the treatment area to remain uncluttered, especially when multiple needle are being placed, such as in a bipedicular procedure. Additional advantages will be apparent to those of skill in the art from the figures, description and claims provided herein.
The invention may best be understood by reference to the following description taken in conjunction with the accompanying drawings in which:
While the present invention is described in detail, it is to be understood that this invention is not limited to particular variations set forth herein as various changes or modifications may be made to the embodiments described and equivalents may be substituted without departing from the spirit and scope of the invention. As will be apparent to those of skill in the art upon reading this disclosure, each of the individual embodiments described and illustrated herein has discrete components and features which may be readily separated from or combined with the features of any of the other several embodiments without departing from the scope or spirit of the present invention. In addition, many modifications may be made to adapt a particular material, composition of matter, process, process act(s) or step(s) to the objective(s), spirit or scope of the present invention. All such modifications are intended to be within the scope of the claims made herein.
Methods recited herein may be carried out in any order of the recited events which is logically possible, as well as the recited order of events. Furthermore, where a range of values is provided, it is understood that every intervening value, between the upper and lower limit of that range and any other stated or intervening value in that stated range is encompassed within the invention. Also, it is contemplated that any optional feature of the inventive variations described may be set forth and claimed independently, or in combination with any one or more of the features described herein.
All existing subject matter mentioned herein (e.g., publications, patents, patent applications and hardware) is incorporated by reference herein in its entirety except insofar as the subject matter may conflict with that of the present invention (in which case what is present herein shall prevail). The referenced items are provided solely for their disclosure prior to the filing date of the present application. Nothing herein is to be construed as an admission that the present invention is not entitled to antedate such material by virtue of prior invention.
Reference to a singular item, includes the possibility that there are plural of the same items present. More specifically, as used herein and in the appended claims, the singular forms “a,” “an,” “said” and “the” include plural referents unless the context clearly dictates otherwise. It is further noted that the claims may be drafted to exclude any optional element. As such, this statement is intended to serve as antecedent basis for use of such exclusive terminology as “solely,” “only” and the like in connection with the recitation of claim elements, or use of a “negative” limitation. Last, it is to be appreciated that unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this invention belongs.
The systems of the present invention may be configured for use in any suitable minimally invasive procedure that involves accessing a target site within a patient. As discussed herein, the subject systems are particularly suitable for accessing and treating vertebral bodies and long bones. In certain embodiments, the system further includes one or more treatment devices suitably configured for treating a degenerative intervertebral disc.
The treatment device of the present invention may have a variety of configurations and characteristics as described below. However, one variation of the invention employs a tissue treatment device using Coblation® technology developed by the assignee. A more detailed discussion of spinal applications and devices using Coblation® technology may be found as follows: issued U.S. Pat. Nos. 6,105,581; 6,283,961; 6,264,651; 6,277,112; 6,322,549; 6,045,532; 6,264,650; 6,464,695; 6,468,274; 6,468,270; 6,500,173; 6,602,248; 6,772,012; and 7,070,596 each of which is incorporated by reference, and pending U.S. patent applications Ser. No. 09/747,311 filed Dec. 20, 2000 and Ser. No. 10/656,597 filed Sep. 5, 2003 both of which are incorporated by reference.
The description below includes an example of the inventive method as applied to a vertebroplasty or kyphoplasty procedure. However, it is understood that the invention is not limited to vertebroplasty and kyphoplasty procedures. It is also understood that while this invention is described using fluoroscopy, other radiographic imaging systems may be used, for example CT or X-ray. The access assembly configurations disclosed herein may be used in any procedure where it is desired to establish cannular access to a bone structure or another tissue structure. Moreover, other treatment modalities (e.g., chemical, other electrosurgical devices, etc.) may be used with the inventive method either in place of Coblation® technology as discussed herein or in addition thereto.
Now referring to
Elongate body 110 includes a generally smooth outer surface 120 and a generally smooth, substantially inviolate inner luminal surface 122 as shown in
Now referring to
Outer member 160 is substantially circular and includes opening 164. Opening 164 is shown to be approximately 0.157 inches. In alternate embodiments opening 164 may be substantially smaller or substantially closed, provided alignment guide 130 is somewhat plastic and deformable. The user may then bend, twist or temporarily deform alignment guide 130 in order to attach it to tubular body 110. Contrarily this opening 164 may be significantly larger. In such embodiments outer member 160 may be semi circular in shape for example, or outer member arc angle 166 may be less than 270 degrees. Alignment guide 130, in this case, may be smaller in overall size and less likely to interfere during the placement of multiple access assemblies 100.
In the present embodiment, member 160, hub 151 and radial supports 154 are molded as a single component and are constructed of a relatively radiolucent and possibly biocompatible material including, but not limited to, for example, polycarbonate, various polyolefins (e.g. polyethylene, polypropylene), nylon, polystyrene, polysulfone, PEEK, ABS, are examples. Biocompatibility is only a requirement to the extent of contact with surgeon's hands—not contact with patient's internal tissues. Outer member 160 further includes at least one radiopaque alignment indicator or “landmark” 162 disposed thereon. In the embodiment of
As shown in
A further alternative embodiment, not expressly shown, includes at least one radiopaque indicator 162 inside outer member 160. Alignment guide 130 is substantially the same shape as alignment guide described in previous embodiments. In this embodiment radiopaque wires or strips of material forming a substantially circular shape may be overmolded or encapsulated within a radiolucent alignment guide 130 during the manufacturing process.
In the present embodiment, body 260 is connected with attachment portion via radial support members 254. Three radial support members 254 connect attachment portion with body 260; in alternate embodiments, more or fewer radial support members 254 may be used. Attachment portion 250 includes hub 251 and center opening 253. Hub 251 is substantially circular and includes opening or gap 252 defined by slot 255. Attachment portion 250 and the dimensions of center opening 253 and gap 252 are preferably selected to facilitate the removable attachment of alignment guide 230 onto outer surface 120 of tubular body 110. For instance, in particular embodiments opening 252 and center opening are sized for attachment on cannulas 102 of a selected standard size such as, for instance a 13 gauge, 11 gauge or 8 gauge cannula or any other suitable standard cannula.
In general, alignment guides 130, 230 or 330 may be any size 157, 257 or 357 and thickness 175, 275 or 375 that is practical. As guides 130, 230 or 330 have a larger diameter and thick, the more precise the use of the alignment landmarks 162, 362 may be. However to be practical, the diameter (or other longest dimension for non-circular embodiments) would not significantly exceed handle 112 dimensions so as to make it easy to use.
Once longitudinal axis 422 and fluoroscope axis 414 are parallel, a radiographic or fluoroscopic image similar to that shown in
When access assembly axis 422 and fluoroscope axis 414 are not substantially parallel, fluoroscope 412 may show an image similar to that shown in
Now referring to
A subject kit such as kit 500 typically may preferably include instructions 560 and other pertinent documentation for using the subject systems, e.g., cannula 510 and stylet 520, in methods according to the subject invention. Instructions 560 for practicing the subject methods are generally recorded on a suitable recording medium. For example, the instructions may be printed on a substrate, such as paper or plastic, etc. As such, instructions 560 may be present in the kits as a package insert or in the labeling of the container of the kit or components thereof, i.e., associated with the packaging or subpackaging. In other embodiments, instructions 560 may include electronic data stored on a suitable computer readable storage medium, e.g., CD-ROM, DVD, diskette, etc. In yet other embodiments, the actual instructions are not present in the kit, but means for obtaining the instructions from a remote source, e.g., via the Internet, are provided in lieu of instructions 560. An example of this embodiment is a kit that includes a web address where the instructions may be viewed and/or from which the instructions may be downloaded. As with the instructions, this means for obtaining the instructions is recorded on a suitable substrate.
Now referring to
In the present embodiment tool system 600 is advanced until the distal end of cannula 610 accesses cancellous bone 606. Following the desired placement of tool system 600 within bone structure 602, stylet 612 is preferably removed, opening lumen 624 within cannula 610 and thereby providing access to cancellous tissue 606, as shown in
Now referring to
In alternate embodiments treatment device 650 may comprise any mechanical or electrosurgical device suitable for treating target tissue such as cancellous tissue 606 or tumor tissue existing within a bone structure. Treatment of target tissue may include, but is not limited to, heating, cutting, ablating and removing the target tissue.
Now referring to
Following initial placement of expandable structure 662, expandable structure is expanded, as shown in
Following initial placement of cannula 610, the treatment of cancellous tissue 606 and/or the use of an expandable device 662, cement or filler material may be introduced into the target site of bone structure 602, as shown in
As shown, a first alignment guide portion 711 extends from first distal end 708 and a second alignment guide portion 713 extends from second distal 709. Each alignment guide portion 711 and 713 is substantially semicircular in shape and includes a radiopaque alignment indicator portion 714 and 716 towards the outer circumference of each guide 711 and 713.
Once the forceps assembly 700 is in a closed position, these indicator portions 714 and 716 form an approximate circular shape. In alternate embodiments, the distal end of forceps assembly, when in a closed position may generally approximate the features of any of the alignment guide embodiments described in
Now referring to
Handle 812 includes a first surface 840 and second surface 842, separated by thickness 844. First surface 840 and second surface 842 are substantially parallel to each other and substantially perpendicular to elongate tubular body longitudinal axis 850. A first radiopaque landmark 830A is disposed on said first surface 840 and a second radiopaque landmark 830B is disposed on said second surface 842. Both landmarks 830 are substantially circular in shape, and first landmark 830A is concentric with 830B. Landmarks 830 do not need to be a complete circle, but enough of a circle to make landmarks 830 easy to visualize on an imaging system. Landmark 830A is shown on
Handle 812 material is constructed of a relatively radiolucent material. Landmarks 830 may be constructed from stainless steel of any other suitable radiopaque material or compound and comprised of a wire or narrow strip of material disposed on or in said handle 812.
As shown in
Another alternative embodiment, shown in
A method of performing a medical procedure using alignment guide is shown in
Treating the tissue may include inserting a distal end of a tissue ablation device 906 in the cannula and removing tissue from the target location 907.
Treating the target tissue may include inserting an expandable structure in the cannula 908, positioning the expandable structure within the target tissue 909 and causing the expandable structure to assume an expanded geometry 910.
The target tissue may be a portion of cancellous bone within a vertebral body and treating this tissue may include injecting a settable implant material 911 into the cancellous bone.
Although only a few embodiments of the present invention have been described, it should be understood that the present invention may be embodied in many other specific forms without departing from the spirit or the scope of the present invention. Therefore, the present examples are to be considered as illustrative and not restrictive, and the invention is not to be limited to the details given herein, but may be modified within the scope of the appended claims.
