This invention relates to medical methods and apparatus.
A vertebral compression fracture (VCF) can occur when a vertebral body is too weak to support a load and the spine collapses. A VCF may cause the spine to shorten, leading to spinal deformities and altering spinal biomechanics. Collapse may result in thoracic and lumbar spinal deformity and is often seen in elderly people. The spinal deformity, commonly known as a Dowager's Hump, is also referred to as kyphosis. Several causes can lead to a VCF, including osteoporosis, cancer or a traumatic incident, such as a fall or car accident.
A treatment for a VCF can involve injecting a material into vertebra, either at low or high pressure. Optionally, a surgical balloon can first be inserted into a vertebra and expanded to restore a collapsed vertebra to its original shape. A material can then be inserted into the restored vertebra, which, upon hardening, can maintain the original shape of the vertebra. The technique of inserting a material into a cavity, such as a collapsed vertebra, can also be used to treat other medical conditions, for example, in knee or hand joints.
This invention relates to a method and apparatus for filling a cavity in a patient's body with a material. In general, in one aspect, the invention features an apparatus including a flexible tube, a barrel and a plunger. The flexible tube has a rigid first end, a second end, and a lumen extending from the first end to the second end and operable to hold a material for conveyance through the rigid first end into a cavity. The barrel is in fluid communication with the second end of the flexible tube and includes a lumen configured to receive material for delivery into the flexible tube. The plunger is configured to advance material through the lumen in the barrel and into the flexible tube. There is substantially a one to one ratio of advancement of the plunger to a volume of material advanced from the rigid first end of the flexible tube.
In general, in another aspect, the invention features an apparatus including a flexible tube, a barrel and a plunger. The flexible tube has a rigid first end, a second end, and a lumen extending from the first end to the second end and operable to hold a material for conveyance through the rigid first end and into a cavity. The barrel is in fluid communication with the second end of the flexible tube and includes a lumen configured to receive material for delivery into the flexible tube. The barrel's lumen has a diameter substantially the same as a diameter of the flexible tube's lumen. The plunger is configured to advance material through the lumen in the barrel and into the flexible tube.
In general, in another aspect, the invention features an apparatus including a flexible tube, a barrel and a plunger. The flexible tube has a first end and a second end, and a lumen extending from the first end to the second end and operable to hold a material for conveyance through the first end. The barrel is in fluid communication with the second end of the flexible tube and includes a lumen configured to receive material for delivery into the flexible tube. The plunger is configured to advance material through the lumen in the barrel and into the flexible tube.
In general, in another aspect, the invention features an apparatus including a flexible tube, a barrel, a cartridge and a plunger. The flexible tube has a rigid first end, a second end, and a lumen extending from the first end to the second end and operable to hold a material for conveyance through the rigid first end into a cavity. The barrel is in fluid communication with the second end of the flexible tube and includes a lumen configured to receive a cartridge pre-loaded with material for delivery into the flexible tube. The cartridge is configured for insertion into the barrel and includes a lumen configured to receive material for delivery into the flexible tube. The plunger is configured to advance material through the lumen in the cartridge and into the flexible tube, such that there is substantially a one to one ratio of advancement of the plunger to a volume of material advanced from the rigid first end of the flexible tube.
Implementations can include one or more of the following features. The apparatus can further include a cannula having a first end configured to receive the first end of the flexible tube and having a second end configured to provide the first end of the flexible tube access to the cavity. The lumen of the flexible tube can be pre-loaded with the material, and the plunger can be operable to advance material through the lumen in the barrel into the flexible tube. The pre-loaded material in the flexible tube is thereby advanced through the lumen and into the cavity.
The apparatus can further include a connector (e.g., a luer fitting) connecting the flexible tube to the barrel, where the flexible tube is connected to the barrel such that a longitudinal axis of the barrel is at an angle in the range of 0° to 90° to a longitudinal axis of the flexible tube. In one implementation, the angle is substantially 40° to 50°. The barrel can include threads on an end of the lumen and the connector can further include threads configured to mate with the threads on the barrel. An assembly of the flexible tube connected to the barrel can be pre-loaded with the material, where the plunger is operable to advance at least some of the pre-loaded material into the cavity.
The barrel can further include a plurality of lumens disposed in the barrel and configured to receive material for delivery into the flexible tube. The barrel can be rotatable about a longitudinal axis of the barrel, and each lumen of the plurality of lumens can be preloaded with material. Once a lumen has been emptied into the flexible tube by action of the plunger, the plunger can be withdrawn, the barrel can be rotated and the plunger can engage a next lumen to fill the flexible tube.
The apparatus can further include a cartridge configured to receive material for delivery into the flexible tube, where the barrel's lumen is configured to receive the cartridge and to receive the material via the cartridge, and the plunger is configured to advance material through the lumen in the barrel via advancement through the cartridge.
The apparatus can include a plurality of cartridges configured for insertion into the barrel, each cartridge including a lumen configured to receive material for delivery into the flexible tube. The barrel can further include a plurality of lumens configured to receive a plurality of cartridges. The barrel is rotatable about a longitudinal axis of the barrel and each lumen can be loaded with a cartridge pre-loaded with material, such that once a cartridge has been emptied into the flexible tube, the barrel can be rotated and a next cartridge used to fill the flexible tube.
Implementations of the invention can realize one or more of the following advantages. The cavity filling assembly can allow an operator of the assembly to perform a cavity filling operation, while keeping the operator's hands outside of an x-ray field created by an imaging device required to assist the operator in maneuvering the assembly during the operation. For example, in a kyphoplasty procedure to fill a vertebra with bone filling cement, a C-arm imaging device is typically used to provide the operator with instantaneous imaging information necessary for the operator to perform a cavity filling operation. Preferably, the operator is able to manipulate the necessary cavity filling apparatus throughout the kyphoplasty procedure while only minimally exposing, if at all, his or her own body to an x-ray field created by the C-arm imaging device. The cavity filling assembly described herein is configured to allow the operator to keep his or her hands a distance from the C-arm imaging device while performing a cavity filling operation.
The cavity filling assembly can be configured so as to be positioned during a cavity filling operation such that a material can be advanced through the assembly without interfering with an imaging device also required to perform the operation. For example, in a kyphoplasty procedure, a C-arm imaging device is typically used as discussed above. There can be relatively little clearance between the C-arm imaging device and the patient's body. The cavity filling assembly includes a nozzle assembly that can be inserted into a cannula that has been inserted into the patient's body. A barrel attached to the nozzle assembly can be used to receive the cavity-filling material and operate as a handle for the operator. A connector between the nozzle assembly and the barrel can be configured to connect the nozzle assembly to the barrel at a range of different angles. For example, the angle can be selected to accommodate the clearance between an imaging device and a patient's body, while maintaining a suitable flow path for the material through the cavity filling assembly.
The cavity filling assembly can be configured to allow all of the cavity filling material necessary for a cavity filling operation to be loaded into the assembly at one time, so that iterative loading procedures are not required during the cavity filling operation. For example, a barrel including multiple chambers is described, where each chamber can be loaded with a cavity filling material, either directly or by inserting a loaded cartridge into the chamber. By providing multiple chambers, the barrel can be loaded at the start of the operation with sufficient material to completely fill the cavity, thereby facilitating the procedure.
The details of one or more embodiments of the invention are set forth in the accompanying drawings and the description below. Other features, objects, and advantages of the invention will be apparent from the description and drawings, and from the claims.
FIGS. 8A-C show an alternative implementation of a multi-chambered barrel assembly.
Like reference symbols in the various drawings indicate like elements.
An apparatus and method is described for injecting a material into a cavity in a patient's body. For illustrative purposes, the apparatus and method shall be described in the context of injecting a bone filling cement into a vertebra of a patient to treat kyphosis, although the apparatus and methods can be used to treat other conditions.
Referring to
Referring to
The loaded cartridge 122 is inserted into the barrel 104 as shown in
The nozzle assembly 102 can be primed, i.e., pre-loaded with the material, so that when the plunging rod is pushed through the cartridge 122 and the material advances from the cartridge 122 into the nozzle assembly 102, the pre-loaded material in the nozzle assembly 102 is forced out of the distal end 110 and into the cavity 116 (
Referring again to FIGS. 1A-C and 2, including the flexible tube 108 in the nozzle assembly 102 can make it easier for an operator of the cavity-filling assembly 100 to maneuver the device during a cavity filling operation. For example, a C-arm imaging device for fluoroscopy may be used to provide instantaneous imaging data to the operator to assist the operator in filling a cavity 116 with the material. Maneuvering a cavity-filling device while constrained by the clearance between the C-arm imaging device and the patient's body can be difficult. The flexible tube 108 allows flexibility in positioning the cavity filling assembly 100 to accommodate the clearance constraint. Including a rigid distal end 110 at the end of the flexible tube 108 can make it easier for the operator to control the distal end 110 within the cavity 116, particularly while discharging the material into the cavity 116. The distal end 110 may include different configurations to further control dispensing of the cavity filling material.
Other implementations of the cavity-filling assembly 100 are possible, including a cavity-filling assembly 100 with a differently configured nozzle assembly 102. In one implementation, the nozzle assembly 102 can be a flexible tube 108 without a rigid distal end 110, i.e., an entirely flexible nozzle assembly 102. In another implementation, the flexible tube 108 can be replaced with a rigid tube. That is, the nozzle assembly 102 can be entirely rigid.
Referring to
Other embodiments of the connector 106 can be used. For example, a different fitting can be used in place of the luer fitting 130, e.g., a snug-fit, snap-on fit, or tapered fitting. The threads 132 formed on the connector 106 are optional.
Referring again to FIGS. 1A-C, the barrel 104 provides an extension from the nozzle assembly 102 that an operator can use as a handle during a cavity filling operation. The barrel 104 also acts to distance the operator's hands from the patient's body, which can also act to keep the operator's hands outside of a potentially harmful imaging field. For example, as described above, in a kyphoplasty operation a C-arm imaging device is typically used during the cavity filling operation to provide instantaneous imaging information to the operator. The barrel 104 operates as an extender that keeps the operator's hands and arms out of the imaging field created by the imaging device. The length of the barrel 104 and the length of the flexible tubing 108 can be designed based on how far the operator's hands must be from the imaging field. Further, there may be a relatively small clearance between the C-arm imaging device and the patient's body. The connector 106 between the nozzle assembly 102 and the barrel 104 allows the barrel 104 to be angled relative to the nozzle assembly 102 to achieve preferred flow characteristics. The flexible tubing 108 allows for low clearance. In one implementation, the barrel and plunging assembly can be a syringe.
The cavity-filling assembly 100 shown in
In either the two-part or unitary cavity-filling assembly 100 implementations, the barrel 104 can be configured to have substantially the same inner diameter as the nozzle assembly 102, so as to maintain a constant pressure across the cavity-filling assembly 100 as the material is advanced therethrough. Alternatively, the barrel 104 can be configured to have a larger inner diameter than the nozzle assembly 102, to increase the amount of material that can be preloaded into the cavity-filling assembly 100, thereby minimizing the number of loading iterations necessary to fill a cavity 116 (
A cavity filling operation may require that the nozzle assembly 102 and barrel 104 be reloaded (either directly or via a cartridge 122) with material more than once in order to completely fill the cavity. As shown in
FIGS. 8A-C show an alternative implementation of a multi-chambered barrel assembly 800. The barrel assembly 800 includes a barrel 802 rotatable about a longitudinal axis within a sleeve 802.
In one implementation where the barrel 104 is loaded with the material directly rather than using a cartridge 122, the distal end of the barrel 104 used to load the material into the barrel 104 is configured to mate with a mixer used to mix and contain the material. Referring to
In one implementation, the cartridge 122 can be a KyphX® Bone Filler Device available from Kyphon Inc. The cartridge 122 (or nozzle) can include a fitting configured to mate with a fitting on a dispenser of a mixer, such as the mixer 200 shown in
Referring again to FIGS. 3A-B, in one implementation, the plunging assembly 120 is included with the KyphX® Bone Filler Device available from Kyphon Inc. The plunging assembly 120 is configured to plunge the cartridge 120 (or nozzle) of the KyphX® Bone Filler Device available from Kyphon Inc. Alternatively, if the barrel 104 of the cavity-filling assembly 100 is to be loaded directly with the material (rather than via a loaded cartridge), then the plunging assembly 120 can be adapted to plunge the barrel 104, for example, to accommodate the interior diameter and length of the barrel 104.
The cavity filling assembly 100 is assembled (step 606), if necessary. For example, if the cavity filling assembly includes a separate nozzle assembly 102 and barrel 104, then the barrel 104 and nozzle assembly 102 can be joined by the connector 106. The cavity filling assembly 100 is inserted into a cannula 114 that has been positioned within the cavity 116 in the patient's body (step 608). In one implementation, one or more surgical balloons are first inflated within the cavity 116 to restore the cavity 116 to an original shape or to create or enlarge the cavity 116. The surgical balloons are removed, and optionally material, such as bone, may be removed from the cavity 116. Once the cavity is prepared, the cavity filling assembly 100 is inserted into the cannula 114.
The material is advanced from the cavity filling assembly 100 into the cavity 116 (step 610). This step can include, if necessary, inserting one or more cartridges 122 into the barrel 104 to load the barrel 104 with the material, i.e., in a configuration where the barrel 104 is not directly loaded with the material. A plunging assembly 120 is positioned to either plunge the barrel 104 or a cartridge 122 contained within the barrel 104. The plunging rod 122 is advanced into the barrel 104 or cartridge 122 to advance the material through the cavity filling assembly 100 and out the distal end 110 that is positioned within the cavity 116.
The operator can control the advancement of the plunging rod 122, thereby controlling the advancement of the material into the cavity 116. In one implementation, the material is advanced into the cavity 116 at a low pressure. If the inner diameters of the components of the cavity filling assembly 100, i.e., of the nozzle assembly 102 and barrel 104 or cartridge 122, are substantially the same, then the advancement of the plunging rod 122 is directly proportional to the advancement of the material from the distal end 110 of the nozzle assembly 102 into the cavity 116 (i e., an approximate one-to-one ratio). In one implementation, the diameters of the components of the cavity filling assembly 100 are uniform and allow for no drop-off or build-up of pressure in the cavity filing material. Further, the operator can retract the nozzle assembly 102 from the cannula 114 while advancing the plunging rod 122, thereby pulling the distal end 110 out of the cavity 116 as the cavity 116 is filled with the material. That is, the front portion of the cavity can be filled first with the viscous material to ensure a solid, compact fill with no air gaps. The one-to-one ratio of the advancement of the plunging road to the advancement of the material, and the ability to retract the nozzle assembly 102 from the cavity 116 during the filling operation provides improved control to the operator over the cavity filling procedure.
The cavity filling assembly 100 can be formed from any suitable material or combination of materials. The materials selected must be compatible with the cavity filling material that will be advanced through the assembly 100. The materials used for the flexible tubing 108 should also provide kink resistance, burst resistance and thermal resistance. The flexible tube 108 can be formed from polyamides, nylon, Teflon®, or nylon with a Teflon lining, Pebax®, PEEK, polypropylene, polyethylene, PTFE, FEP, PFA, Radel® R polyphenylsulphone and the distal end can be formed from stainless steel. In a preferred embodiment, the flexible tubing can be formed of Pebax® with an inner stainless steel coil reinforcement. Examples of material for the barrel 104 and connector 106 include nylon, polyethylene, polycarbonate, aluminum, Radel® R polyphenylsulphone or stainless steel.
A number of embodiments of the invention have been described. Nevertheless, it will be understood that various modifications may be made without departing from the spirit and scope of the invention. The logic flow depicted in
This application is a continuation-in-part of, and claims priority to, pending U.S. application Ser. No. 10/617,976, filed on Jul. 11, 2003, which is a divisional application of U.S. application Ser. No. 09/804,107, filed Mar. 12, 2001, now U.S. Pat. No. 6,613,054 issued Sep. 2, 2003, to Scribner, et al, which is a divisional application of U.S. application Ser. No. 09/134,323, filed Aug. 14, 1998, now U.S. Pat. No. 6,241,734 issued Jun. 5, 2001, Scribner et al. Priority is claimed to the above referenced applications and the contents of the above referenced applications are hereby incorporated by reference herein in their entirety.
Number | Date | Country | |
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Parent | 09804107 | Mar 2001 | US |
Child | 10617976 | Jul 2003 | US |
Parent | 09134323 | Aug 1998 | US |
Child | 09804107 | Mar 2001 | US |
Number | Date | Country | |
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Parent | 10617976 | Jul 2003 | US |
Child | 10979781 | Nov 2004 | US |