1. Field of the Invention
The present invention generally relates to kyphoplasty. More particularly, the invention relates to a method and apparatus for performing kyphoplasty.
2. Description of Related Art
Vertebral compression fractures represent a generally common spinal injury, cause pain and spinal deformity, and may result in prolonged disability. These fractures involve the collapse of one or more vertebral bodies in the spine and can result, for example, from metastatic diseases of the spine, from trauma, or can be associated with osteoporosis.
Kyphoplasty is a minimally-invasive procedure that has been developed to access and treat diseased or fractured bone, such as collapsed or fractured vertebral bodies. In a kyphoplasty procedure, a surgeon manipulates the cancellous and/or cortical bone of the weakened and/or fractured vertebral body with surgical tools, and then introduces a bone-filling material such as bone cement into the bone, desirably into a cavity formed within the vertebral body, in an attempt to repair, reinforce and/or prevent further fracture or subsidence of the bone. This procedure seeks to reduce the pain and discomfort experienced by patients suffering from vertebral compression fractures.
A source of complication with the kyphoplasty technique is leakage of the bone-filling material which can cause compression of the spine or the dorsal nerves, or pulmonary embolism caused by leakage of the bone-filling material into the veins. Because of this hazard, the bone-filling material must be very viscous. This requires large needles, high needle insertion force, and high injection pressure, all of which create risk to the patient. Leakage into the arterial system is less of a concern because the arteries break up into small arterioles. Venous returns, however, are located in the center of the anterior and posterior walls of the vertebral cavity and are large. Therefore, leakage of the bone-filling material into the veins is a major concern.
To lessen leakage complications, a kyphoplasty procedure using a resorbable balloon-tipped catheter has been proposed, wherein the catheter is inserted into a fractured vertebral body and a bone-filling material is injected through the catheter and into the expandable balloon to stabilize the fracture. The balloon is held in place until the bone-filling material begins to set which prevents leakage of the bone-filling material into the bloodstream. The catheter is removed and the balloon remains in place within the vertebral body and resorbs over time. This technique minimizes the opportunities for leakage of the bone-filling material outside of the targeted bone.
While this procedure has been shown to reduce some pain associated with vertebral compression fractures, it has certain inherent drawbacks. The bone-filling material is contained within the balloon as it sets, preventing adhesion of the bone-filling material to the vertebral fragments. Although the balloon filled with the bone-filling material may provide a large enough lump in between vertebral fragments to prevent them from grinding together, the bone-filling material is not well integrated with the vertebral body which can lead to relative motion between the bone-filling material and the vertebral fragments, causing the patient pain.
Accordingly, there is a need to provide an improved method and apparatus for performing kyphoplasty which relieves pain caused by vertebral compression fractures and prevents leakage of bone-filling materials into the bloodstream of a patient.
Embodiments of the present invention provide a balloon catheter and a method for performing kyphoplasty which promotes healing of fractured vertebral bodies and prevents leakage of a bone-filling material into the bloodstream of a patient, thereby reducing patient discomfort associated with vertebral fractures. This invention also allows the use of a less viscous bone-filling material, which improves working time and allows for smaller instruments (i.e., a smaller injection needle and balloon catheter).
In at least one embodiment of the present invention, a balloon catheter for insertion into a vertebral body having first and second endplates is provided. The balloon catheter comprises a shaft having a proximal end and a distal end. A lumen extends through the shaft along a longitudinal axis. An inflatable balloon is positioned near the distal end of the shaft. The balloon has an uninflated configuration and an inflated configuration. The balloon has a proximal portion and a distal portion, an interior and an exterior. The lumen is in fluid communication with the interior of the balloon. An expandable band is wrapped around a section of the exterior of the balloon in a generally proximal-distal direction.
In at least one other embodiment, a balloon catheter for insertion into a vertebral body having first and second endplates is provided is provided. The balloon catheter comprises a shaft having a proximal end and a distal end. A lumen extends through the shaft along a longitudinal axis. An inflatable balloon is positioned near the distal end of the shaft. The balloon has an uninflated configuration and an inflated configuration. The balloon has a proximal portion and a distal portion, an interior and an exterior. The lumen is in fluid communication with the interior of the balloon. An expandable band is wrapped around a section of the exterior of the balloon in a generally proximal-distal direction. The balloon includes a first section, a second section, and a third section. The second section is disposed between the first and third sections and the band is wrapped around the second section. The balloon catheter is configured to be inserted into the vertebral body such that the first section of the balloon substantially opposes the first endplate and the third section of the balloon substantially opposes the second endplate such that the band wrapped around the second section of the balloon is configured to expand in a generally lateral direction relative to the vertebral body when the balloon is inflated.
In at least one other embodiment, a method of performing kyphoplasty is provided. The method comprises providing a balloon catheter including a shaft having a distal end and a proximal end. A lumen extends through the shaft along a longitudinal axis. An inflatable balloon having an uninflated configuration and an inflated configuration is positioned near the distal end of the shaft. The balloon includes a proximal portion and a distal portion and an interior and an exterior. The lumen is in fluid communication with the interior of the balloon. An expandable band is wrapped around a section of the exterior of the balloon in a generally proximal-distal direction.
The balloon catheter is positioned for insertion into a vertebral body having first and second endplates and inserted into the vertebral body when the balloon is in the uninflated configuration. A cavity is formed within the vertebral body by inflating the balloon to the inflated configuration which expands the band to an expanded configuration. The balloon catheter is removed from the vertebral body by deflating the balloon to the uninflated configuration and removing the shaft and balloon from the vertebral body. The band is configured to at least partially maintain the expanded configuration during deflation of the balloon and remains within the vertebral body during removal of the shaft and the balloon. A bone-filling material is dispensed into the cavity of the vertebral body. The band is configured to prevent leakage of the bone-filling material in a generally lateral direction relative to the vertebral body and facilitate adhesion of the bone-filling material to the vertebral body in a generally vertical direction relative to the vertebral body.
Further objects, features and advantages of this invention will become readily apparent to persons skilled in the art after a review of the following description, with reference to the drawings and claims that are appended to and form a part of this specification.
a is a side view of a device for stabilizing a collapsed vertebral body in accordance with an embodiment of the present invention, showing the balloon in the uninflated configuration and the band in the unexpanded configuration;
b is a top cross-sectional view of
a is a side view of the device in
b is a top cross-sectional view of
a is a side view of the device in
b is a top cross-sectional view of
a-d are partial side views of a device for stabilizing a collapsed vertebral body in accordance with embodiments of the present invention;
e is a top cross-sectional view of
a is a partial side view of a device for stabilizing a collapsed vertebral body in accordance with another embodiment of the present invention;
b is a partial side view of a stabilized collapsed vertebra in accordance with one example of the present invention;
a is a side view of a device for stabilizing a collapsed vertebral body in accordance with another embodiment of the present invention, showing the balloon in the uninflated configuration and the band in the unexpanded configuration;
b is a side view of a device for stabilizing a collapsed vertebral body in accordance with another embodiment of the present invention, showing the balloon in the uninflated configuration and the band in the unexpanded configuration; and
The present invention generally provides a balloon catheter device for treating damaged vertebral bodies. The device forms a cavity within a damaged vertebral body for receiving a bone-filling material and prevents leakage of the bone-filling material into a patient's bloodstream. Embodiments of the present invention seek to overcome the complications associated with leakage of the bone-filling material and promote adhesion of the bone-filling material with vertebral fragments within the vertebral body to repair the damaged vertebral body and reduce patient discomfort.
Referring now to the drawings,
The collapsed vertebral body 12 may be stabilized by kyphoplasty, a medical procedure for introducing a bone-filling material into the collapsed vertebra. This procedure stabilizes the collapsed vertebra by forming a cavity within the interior open spaces within the cancellous bone of the vertebral body 12 which is subsequently filled with a bone-filling material to provide a more continuous and solid form. Kyphoplasty may further stabilize the vertebral body 12 by restoring vertebral spacing which alleviates nerve pinching from the vertebra 10. It should be noted that the present invention applies to this medical procedure and other procedures for stabilizing and/or repairing damaged bones of patients.
Desirably, kyphoplasty is performed under a local anesthesia and/or a light sedative. A small nick is made in the skin near the spine and an insertion instrument is inserted percutaneously into the fractured vertebral body 12 through, preferably, a targeted area of the patient's back. The insertion instrument may be any type and size of hollow instrument, preferably having a sharp end. For example, the insertion instrument may include a hollow needle having a hollow lumen configured to permit the passage of various instruments and materials. The hollow needle, for instance, may be anywhere from a six to a 14 gage needle. As illustrated in
Referring to
In this embodiment, an expandable, and preferably resorbable, band 64 is wrapped around a section of the balloon 52 in the proximal-distal direction, i.e., the band 64 is wrapped around the balloon 52 from at least part of the proximal portion 54 of the balloon 52 toward at least part of the distal portion 56 of the balloon 52. As illustrated in the embodiments of
In this embodiment, the balloon catheter 34 is configured to fit through the hollow interior of the needle body 36 and into the vertebral body 12. An adhesive may be used to keep the band 64 in place around the balloon 52 as the balloon catheter 34 is pushed through the needle body 36 and introduced into the vertebral body 12. The balloon catheter 34 is configured to be positioned within the vertebral body 12 so that the first section 51 of the balloon 52 substantially opposes either of the first and second endplates 14, 15 and the third section 55 of the balloon 52 substantially opposes the other one of the first and second endplates 14, 15.
Thus, the balloon catheter 34 is configured to be positioned within the vertebral body 12 such that the band 64 wrapped around the second section 53 of the balloon 52 is substantially parallel to the first and second endplates 14, 15 and configured to expand generally laterally with respect to the vertebral body 12 when the balloon is inflated. The balloon catheter 34 is likely inserted into the vertebral body 12 on an angle. Therefore, the substantially parallel description includes a parallel relationship, as well as a slightly angled relationship, between the first, second, and third sections 51, 53, and 55 of the balloon 52 and the first and second endplates 14, 15 such that the band 64 wrapped around the second section 53 of the balloon 52 is configured to expand generally laterally with respect to the vertebral body 12.
Referring to
In the embodiments illustrated in
During insertion of the balloon catheter 34, the location of the balloon catheter 34 may be monitored using visualization equipment such as real-time X-Ray, CT scanning equipment, MRI, or any other commonly used monitoring equipment. In this embodiment, once in a desired position within the vertebral body 12, the lumen 58 supplies the balloon 52 with an appropriate volume of inflation medium 40 suitable for use in medical applications including, but not limited to, air, nitrogen, saline or water. The inflation medium 40 may further include a radiopaque fluid to allow the physician to visualize the balloon catheter 34 during inflation. As the inflation medium 40 fills the balloon 52, the balloon 52 inflates from the uninflated configuration 66 to the inflated configuration 68. Likewise, the band 64 expands with the balloon 52 from an unexpanded configuration 70 to an expanded configuration 72.
As the balloon 52 inflates the adhesive bond between the balloon 52 and the band 64 breaks. Alternatively, the hydration of a film of suitable material between the balloon 52 and the band 64, used to hold the balloon 52 and the band 64 together, may cause the balloon 52 and band 64 to become uncoupled. Suitable materials for this application may include many types of water-based gels that become solid when desiccated. With the inflation of the balloon 52, the first section 51 of the balloon 52 moves generally toward the first endplate 14 and the third section 55 of the balloon 52 moves generally toward the second endplate 15, thereby displacing cancellous bone and forming a cavity 38 within the vertebral body 12.
In this embodiment, once a desired cavity size is reached and the inflated balloon 52 has provided sufficient pressure to force at least one of the first and second endplates 14 and 15 of the vertebral body 12 back into their pre-fractured configurations (
The band 64 is preferably formed of small intestinal submucosa (SIS). SIS is a resorbable, acellular, naturally occurring tissue matrix composed of extracellular matrix (ECM) proteins in various growth factors. SIS is derived from the porcine jejunum and functions as a remolding bioscaffold for tissue repair. SIS has characteristics of an ideal tissue engineered biomaterial and can act as a bioscaffold for remodeling of many body tissues including skin, body wall, musculoskeletal structure, urinary bladder, and also supports new blood vessel growth. SIS has been shown to be completely replaced by the patient's own tissues over time. Alternatively, the band 64 may be formed of any other suitable implantable material including, but not limited to, polylactic acid, polyglycolic acid, poly (ortho esters), poly (glycolide-co-trimethylene carbonate), poly-L-lactide-co-6-coprolactone, polyanhydrides, poly-n-dioxanone, poly (PHB-hydroxyvaleric) acid, surgical mesh, graft fabric, and any mixture or composite thereof.
Referring to
As opposed to solutions which seek to prevent leakage of the bone-filling material in all directions, by injecting the bone-filling material into a resorbable balloon and allowing it to cure within the balloon, the band 64, in accordance with embodiments of the present invention, promotes integration of the bone-filling material 78 within the vertebral body 12 and substantially reduces pain associated with the grinding between the solidified bone-filling material 78 and vertebral fragments. Further, the stabilizing solid structure 80 helps restore vertebral spacing and alleviate nerve pinching by adhering to and supporting the collapsed vertebral body 12. Preferably, the structure 80 generally fills in the open spaces of the collapsed vertebral body 12 providing a more dense and continuous vertebral body 12 which enhances mobility of the patient. The band 64, preferably made of SIS, remains in the vertebral body 12 and promotes tissue growth. The positioning of the band 64 allows the body cells to adhere to the SIS and subsequently differentiate, growing into the SIS. The ability to block the venous return from the vertebral body 12 allows the bone-filling material 78 to be less viscous and the instruments (i.e., the needle 32 and balloon catheter 34, as well as the injection system (not shown)) to be smaller and operate under lower pressures. A less viscous bone-filling material 78 will also allow a longer working time of the material, so that the clinician is not as rushed.
It is also within the scope of the present invention for the balloon 52 to be attached to an opening at the distal end 50 of the shaft 46 such that the shaft 46 does not pierce through the balloon 52, but rather the proximal portion 54 of the balloon is bonded to the distal end 50 of the shaft 46 by means known in the art, such as by a suitable adhesive. In this embodiment, the lumen 58 and the interior 60 of the balloon 52 may be in fluid communication via an opening at the distal end 50 of the shaft 46. In this embodiment, the band 64 may be at least partially wrapped around the second section 53 of the balloon 52 and may be pierced by the distal end 50 of the shaft 46 at the proximal portion 76 of the band 64 so as not to obstruct the fluid communication between the lumen 58 and the interior 60 of the balloon 52. When the balloon catheter 34 is removed from the vertebral body 12 after inflation and deflation of the balloon 52 and expansion of the band 64, the distal end 50 of the shaft 46, including the deflated balloon 52, may be withdrawn through an opening in the proximal portion 76 of the band 64 before being withdrawn through the needle 32.
Referring to
The balloon catheter is positioned for insertion into a vertebral body (92). The balloon catheter is then inserted into the vertebral body (94).
A cavity is formed within the vertebral body (96). This includes inflating a balloon to an inflated configuration. This causes a band wrapped around a section of the balloon to expand to an expanded configuration.
The balloon catheter is removed from the vertebral body (98). This includes deflating the balloon to an uninflated configuration and removing a shaft and the balloon of the balloon catheter from the vertebral body. The band is configured to at least partially maintain the expanded configuration during deflation of the balloon. The band remains within the vertebral body during removal of the shaft and the balloon.
A bone-filling material is dispensed into the cavity of the vertebral body (100). The band prevents leakage of the bone-filling material in generally a lateral direction relative to the vertebral body and facilitates adhesion of the bone-filling material to the vertebral body in generally a vertical direction relative to the vertebral body.
As a person skilled in the art will readily appreciate, the above description is meant as an illustration of implementation of the principles this invention. This description is not intended to limit the scope or application of this invention in that the invention is susceptible to modification, variation and change, without departing from spirit of this invention, as defined in the following claims.