Patent Application
20090088723
The present invention relates generally to apparatus and methods for delivering materials into a patient's body, and, more particularly, to apparatus and methods for delivering polymeric particles and/or other materials into body lumens or cavities, e.g., for treating pseudoaneurysms.
A pseudoaneurysm, also known as a “false aneurysm,” results from disruption or injury of a vessel wall, creating a pulsatile build-up of blood and blood clot in communication with the lumen of the vessel. The bleeding to the pseudoaneurysm from the vessel may be contained, at least temporarily, by a blood clot or surrounding tissue structures.
Pseudoaneurysms often result from an accident or a blood vessel being damaged during a surgical procedure, although disease may also contribute to pseudoaneurysm formation. Pseudoaneurysms may heal naturally by thrombosis and need no treatment. However, there is a risk that the pseudoaneurysm may rupture and bleed into the body, such that it is desirable to treat the pseudoaneurysm before such an event occurs. While a pseudoaneurysm may be treated with surgery, it may be useful to treat a pseudoaneurysm with less invasive techniques, e.g., that may be less traumatic for the patient.
The present invention is directed to apparatus and methods for delivering materials into a patient's body. More particularly, the present invention is directed to apparatus and methods for delivering polymeric particles and/or other materials into body lumens or cavities, e.g., for treating a pseudoaneurysm.
In accordance with one embodiment, an apparatus is provided that includes a delivery lumen for carrying an expandable material therein that is dischargeable from the apparatus through an outlet communicating with the delivery lumen. The apparatus may include a plunger and/or other actuator for discharging the material from the outlet of the apparatus. The apparatus may also include one or more elements for positioning the apparatus and/or for imaging the apparatus during introduction into a patient's body. In one embodiment, the apparatus may include a bleed-back channel for receiving fluids within the patient contacted by the device. In particular, blood received in the bleed-back channel may indicate that the device is located at a pseudoaneurysm or other body lumen or cavity intended for treatment. In alternative embodiments, the apparatus may include one or more echogenic and/or radiopaque markers for monitoring the apparatus using ultrasound and/or x-ray imaging. In another embodiment, the apparatus may include a flow sensor that detects laminar and/or turbulent flow of fluids adjacent the apparatus. In particular, a sensor may detect a turbulent flow condition that may indicate when the apparatus is located adjacent or within a pseudoaneurysm. In addition or alternatively, the sensor may detect laminar flow when blood is no longer flowing to and/or within the pseudoaneurysm.
The material carried by the apparatus may include one or more polymeric components, e.g., a bolus of expandable particles. In one embodiment, the material includes xerogel, e.g., freeze-dried hydrogel. The xerogel may rapidly swell when exposed to an aqueous environment, such as within a pseudoaneurysm, and may swell to multiple times its initial mass. The xerogel may also expand to multiple times its initial volume.
In accordance with another embodiment, a method is provided for treating a pseudoaneurysm in communication with a vessel. A delivery device may be inserted through tissue and advanced toward a pseudoaneurysm or other body lumen or cavity being treated. Optionally, the device may include one or more elements, e.g., to locate the device relative to the pseudoaneurysm or other body lumen or cavity. For example, the device may include a bleed-back channel, and blood exiting from the bleed-back channel may indicate that the device is located in the pseudoaneurysm, i.e., when the bleed-back channel is in communication with the pseudoaneurysm. Alternatively, a change in pressure or flow condition may be detected to indicate when the device is disposed adjacent to or within the pseudoaneurysm.
Once the device is inserted into the pseudoaneurysm, an expandable material, e.g., a plurality of particles, may be delivered from the device into the pseudoaneurysm. In one embodiment, before delivering the absorption agent, pressure may be applied to the patient's skin upstream to the vessel communicating with the pseudoaneurysm to reduce or substantially discontinue flow through the vessel adjacent the pseudoaneurysm. This may reduce the risk of the expandable material exiting from the pseudoaneurysm into the vessel. After the material is delivered into the pseudoaneurysm, the material may absorb blood and/or other fluid within the pseudoaneurysm and expand, e.g., to substantially block flow of fluid between the vessel and the pseudoaneurysm, to substantially fill the pseudoaneurysm, and/or to contain blood, clot, and/or other material within the pseudoaneurysm. In another embodiment, the initial size of the particles may be larger than the aneurysm opening such that the particles pose essentially no risk of outflow from the pseudoaneurysm into the vessel.
Optionally, the particles may be coated with and/or otherwise include varying amounts of materials, such as thrombogin or other pro-thrombotic materials. Thus, the blood within the pseudoaneurysm may clot and seal the aneurysm substantially immediately on contact with the particles and thereby may not allow blood flow out from the pseudoaneurysm into the vessel. In addition or alternatively, the polymer may be radiopaque and/or echogenic.
In another embodiment, the polymer may be injected in the form of a flowable material, e.g., a putty-consistent material and, when pressure is applied, a superabsorbent elongate bead, rod, wire, or other extrusion of the flowable material may be extruded from the delivery device or otherwise injected at the site of the pseudoaneurysm.
The material may slowly degrade within the body over a period of time, ranging from a day to one or more months, or the agent may be substantially non-degradable such that the material may not degrade within about one to two years.
In accordance with still another embodiment, an apparatus for treating a pseudoaneurysm or other body cavity is provided that includes an elongate body including a proximal end, a distal end sized for introduction through tissue into a pseudoaneurysm or other body cavity, and a lumen communicating with an outlet on the distal end. A plurality of particles may be provided within the lumen and dischargeable through the outlet into a pseudoaneurysm or other body cavity. The particles, e.g., formed from xerogel, such as freeze-dried hydrogel, may be configured for absorbing fluid within the pseudoaneurysm or other body cavity to cause the particles to expand to substantially fill the pseudoaneurysm or other body cavity.
In accordance with yet another embodiment, an apparatus is provided for treating a pseudoaneurysm or other body cavity that includes an elongate body including a proximal end, a distal end sized for introduction into a pseudoaneurysm or other body cavity, a delivery lumen extending between the proximal and distal ends, and a bleed-back channel extending between the distal end a proximal opening. A plurality of particles may be provided within the delivery lumen and dischargeable through an outlet at the distal end, e.g., a xerogel, such as a freeze-dried hydrogel, that absorbs fluid within the pseudoaneurysm or other body cavity to cause the particles to expand to substantially fill the pseudoaneurysm or other body cavity. The apparatus may also include an actuator operable from the proximal end for discharging the particles from the outlet into a pseudoaneurysm or other body cavity, e.g., a plunger depressible to discharge the particles from the outlet.
In accordance with still another embodiment, a method is provided for treating a pseudoaneurysm or other body lumen or cavity within a patient's body that includes inserting a distal end of a delivery device into tissue having the cavity therein; inserting the distal end of the delivery device into the cavity; delivering from the delivery device into the cavity, the particles absorbing fluid and expanding within the pseudoaneurysm.
In accordance with yet another embodiment, a method is provided for treating a pseudoaneurysm communicating with a vessel that includes introducing a delivery device into tissue adjacent the pseudoaneurysm; monitoring introduction of the distal end using an element on the distal end until the element provides an indication that the distal end is within the pseudoaneurysm; and delivering the particles from the delivery device into the pseudoaneurysm, the particles absorbing fluid and/or expanding within the pseudoaneurysm. The particles may include xerogel, e.g., freeze-dried hydrogel, that may expand upon absorbing fluid within the pseudoaneurysm to substantially fill the aneurysm, substantially isolate the pseudoaneurysm from the vessel, relieve pressure within the pseudoaneurysm, contain blood, clot, other materials within the pseudoaneurysm, and/or deliver diagnostic and/or therapeutic agents into the pseudoaneurysm.
Other aspects and features of the present invention will become apparent from consideration of the following description taken in conjunction with the accompanying drawings.
The drawings illustrate exemplary embodiments in which:
Turning to the drawings,
The tubular member 12 generally includes a proximal end 14, a distal end 16, and one or more lumens 20, 34 extending between the proximal and distal ends 14, 16. The tubular member 12 may be sized and/or shaped for percutaneous insertion into tissue, e.g., having a length between about five and thirty centimeters (5-30 cm) or between about ten and twenty five centimeters (10-25 cm), and an outer diameter between about 0.7 and five millimeters (0.7-5 mm), or between about one and four millimeters (1-4 mm) As shown, the distal end 16 includes a sharpened distal tip 18, e.g., for puncturing skin and/or facilitating advancement of the device 10 through tissue.
The tubular member 12 may be formed from a substantially rigid body, e.g., having sufficient column strength such that the tubular member 12 may be advanced through tissue, e.g., without additional supporting devices. Alternatively, the tubular member 12 may be semi-rigid or substantially flexible, e.g., to permit different orientations for facilitating positioning of the apparatus 10. In such alternatives, the apparatus 10 may include one or more other instruments (not shown), e.g., an internal obturator or an external sheath or introducer (not shown), which may facilitate advancement of the apparatus 10 through tissue. Exemplary materials for the tubular member 12 include metal, such as stainless steel, plastic, or composite materials.
As shown in
The plunger 28 extends longitudinally through the inlet 22 and into the delivery lumen 20, and generally includes a proximal end 29 protruding from the inlet 22 and a distal end 31 disposed within the delivery lumen 20, e.g., initially adjacent or otherwise proximal to the material 27. The plunger 28 is slidable within the delivery lumen 20 and may be operated to advance and/or retract therein, e.g., using a handle 32 on the proximal end 29 of the plunger 28. The plunger 28 also includes a distal end 31, e.g., including a piston or other enlarged region 33 that extends across the delivery lumen 20 and/or slidably engages the wall of the delivery lumen 20. Thus, when the plunger 28 is depressed, the enlarged region 33 causes material 27 in the delivery lumen 20 to be discharged from the outlet 26. Alternatively, other actuators may be provided instead of or in addition to the plunger 28, e.g., for manually or automatically advancing a piston or enlarged region, e.g., similar to enlarged region 33 to discharge material 27 from the delivery lumen 20.
In addition, as shown in
Optionally, the apparatus 10 may include one or more additional features, e.g., in addition to or as an alternative to the bleed-back channel 34. For example, in one embodiment, one or more echogenic elements (not shown) may be provided on the end portion 16, e.g., to facilitate imaging the apparatus 10 using external ultrasound imaging equipment. The echogenic elements may include, for example, bubbles, particles, or discontinuities on a surface of the distal end 16. In an alternative embodiment, one or more radiopaque markers, such as one or more circumferential bands (not shown), may be provided on the distal end 16, e.g., to facilitate imaging the apparatus 10 using fluoroscopy or other x-ray imaging equipment. Such markers may be embedded in or printed on a surface of the tubular member 12, crimped around the tubular member 12, and the like. In yet another embodiment, a series of hashes or other marks (not shown) may be vertically aligned along a length of the tubular member 12. For example, a series of marks scaled from the distal tip 18 may be provided that correspond to the distance to the distal tip 18 from each mark. Such marks may be used to indicate a distance that the distal tip 18 of the apparatus 10 has been inserted into a patient based on the marks exposed above the patient's skin.
Optionally, as shown in
For example, blood flowing through a vessel in communication with a pseudoaneurysm may undergo turbulent flow as it enters, exits, and/or flows within the pseudoaneurysm. In contrast, blood in an uninterrupted vessel may exhibit substantially laminar flow. Thus, a turbulent flow condition may indicate that that the distal end 16′ is located near or within the pseudoaneurysm as opposed to the adjacent tissue or vessel. Also, when blood ceases flowing into, from, and/or within the pseudoaneurysm, the blood in the adjacent vessel may resume laminar flow. Thus, a laminar flow condition or a no flow condition may indicate that blood is no longer entering the pseudoaneurysm from the vessel, as described further elsewhere herein.
Similarly, if the sensor 44′ is a pressure sensor, a relatively low pressure may indicate that the distal end 16′ is within tissue, while an increase in pressure may indicate that the distal end 16′ is within the pseudoaneurysm P.
The sensor 44′ may be coupled to an output device 44,′ e.g., one or more lights or other indicators, a display, and the like, e.g., by one or more leads (not shown), for providing an output based upon the conditions detected by the sensor 44.′ For example, as shown in
For example, when the sensor 44′ detects laminar flow (or no flow), a first light 46a′ may be lit, as shown in
Returning to
In one embodiment, the material 27 may be a PEG polymeric material, e.g., a xerogel or hydrogel formed exclusively by the reaction of high molecular weight PEG-esters with PEG-amines, such as a freeze-dried hydrogel or other xerogel, having a density between about 0.05 and 0.90 grams per cubic centimeter (g/cc). As used herein, “xerogel” refers to a hydrogel material in a dehydrated state, which may be achieved by freeze-drying the hydrogel or by other methods. The term “hydrogel” may be used generically or may refer to the material in a hydrated state. Density, along with the precursor components and/or other process parameters, may affect one or more properties of the xerogel material, e.g., rate of swelling, magnitude of swelling, compressive modulus, and the like. For example, the xerogel may rapidly swell when exposed to an aqueous environment, such as when delivered within a pseudoaneurysm, e.g., swelling between about two hundred and three thousand percent (200-3000%) of the initial mass within about five to sixty (5-60) seconds (“rate of swelling”). In addition or alternatively, the xerogel may expand between about two and fifty (2-50) times in volume from its dehydrated state after being formed to its fully hydrated state (“magnitude of swelling”). Once hydrated, the hydrogel may be absorbed or otherwise degrade within the body over a period of time, e.g., between about one and ninety (1-90) days or between about five and sixty (5-60) days. Alternatively, the hydrogel may be substantially non-degradable, i.e., may not substantially degrade within about one to two years in a physiological environment. Additional information on materials that may be used and/or methods for making and/or using them are disclosed in U.S. Pat. Nos. 6,152,943, 6,165,201, 6,179,862, 6,514,534, and 6,379,373, and in co-pending applications Ser. No. 09/776,120 filed Feb. 2, 2001, Ser. No. 10/010,715 filed Nov. 9, 2001, Ser. No. 10/068,807 filed Feb. 5, 2002, Ser. No. 10/454,362, filed Jun. 4, 2003, and Ser. No. 11/465,791, filed Aug. 18, 2006. The disclosures of these references and any others cited therein are expressly incorporated by reference herein.
The material 27 may be initially prepared in sheet form, e.g., using the methods disclosed in application Ser. No. 11/465,791, incorporated by reference herein. A plurality of particles may then be created from the resulting sheet, for example, by successively punching individual particles or simultaneously punching multiple particles out of the sheet, for example, using a hole punch having desired dimensions for the resulting particles, e.g., one or more diameters between about 0.5-10 millimeters. The diameters of the particles may be substantially uniform or may vary, if desired. Alternatively, the particles may be cut from the sheet using other methods, such as die-cutting, laser cutting, and the like. Optionally, the particles may be synthesized using conventional particle manufacturing technologies, such as oil/water mixture, which may include adjusting the mixture ratio and stirring rate in such a way that desired particle sizes are obtained. The concentration of the solvent and the particles, along with the stirring speed, may be adjusted to obtain a desired final particle size. The particles may then be filtered and dried to obtain xerogel particles.
The porosity of the particles may be adjusted by freeze-drying, or any other process known in the art. Adjusting the porosity of the particles may also adjust the rate at which the particles expand and/or absorb fluid. More specifically, the porosity of the particles may be adjusted so the rate at which the particles absorb bodily fluids is extremely rapid, e.g., having a time to substantial completion of absorption of less than about one and ninety seconds. In another embodiment, the particles may be treated with saline, e.g., to produce a hydrogel, after which the hydrogel may then be dried back to a xerogel state.
Alternatively, the material 27 may be provided as a flowable material within the delivery lumen 20. For example, the material 27 may be a paste or putty-consistent material, e.g., that includes xerogel particles disposed within an inert carrier material. Thus, instead of a bolus of separate particles, an elongate bead, rod, or other extrusion of the material 27 may extruded or otherwise injected from the delivery device 10
The material 27 may be loaded into the delivery lumen 20 of the tubular member 12 during manufacturing or otherwise before the apparatus 10 is delivered to a user. Alternatively, the material 27 may be provided separately from the apparatus 10, e.g., within a bottle or other container, such that a desired amount may be loaded into the delivery lumen 20 immediately before use. Thus, the user may select the size of the bolus desired, e.g., based upon the specific anatomy encountered, and load the desired bolus, e.g., by pouring into the outlet 26 or a side port (not shown) communicating with the delivery lumen 20, inserting the distal end 16 into a container to force material 27 into the outlet 26, or otherwise loading the material 27 into the delivery lumen 20. Alternatively, multiple apparatus 10 (not shown) may be provided to a user, each having different sizes of boluses such that the user may select the appropriate size bolus corresponding to the actual anatomy encountered.
During use, as shown in
Turning to
In one embodiment, the bleed-back channel 34 may be used to locate the end portion 16 within the pseudoaneurysm P. As shown in
In addition or alternatively, the distal end 16 may be monitored using other methods. For example, ultrasound imaging may be used to identify one or more echogenic elements (not shown) on the distal end 16 to facilitate inserting the distal end 16 towards and into the pseudoaneurysm P. Alternatively, fluoroscopic or other x-ray imaging may be used to locate the pseudoaneurysm P and/or the apparatus 10, e.g., to identify one or more radiopaque markers (not shown) on the distal end 16. Radiopaque contrast may be injected upstream of the vessel V to facilitate determining the relative location of the vessel V, the pseudoaneurysm P, and the apparatus 10.
In another alternative, shown in
After the distal end 16 of the apparatus 10 is inserted into the pseudoaneurysm P, the plunger 28 may be depressed to advance the material 27 from the delivery lumen 20 out the outlet 26, as shown in
Optionally, before the material 27 is discharged from the apparatus 10, the user may apply pressure to the patient's skin above a region of the injured vessel V upstream from the pseudoaneurysm P. This may temporarily slow or substantially stop flow through the vessel V adjacent the pseudoaneurysm, which may reduce the risk of the material flowing out of the pseudoaneurysm P into the vessel B.
In the embodiment of
Turning to
Optionally, the material 27 may include one or more diagnostic and/or therapeutic agents. For example, the material 27 may include a pro-thrombotic agent, e.g., thrombogin, to enhance clotting of blood within the pseudoaneurysm, a blood thinner to reduce the risk of clotting, antibiotics, agents to enhance healing, and the like. In addition or alternatively, the material 27 may be coated with, may carry, and/or may otherwise include echogenic and/or radiopaque materials, e.g., which may facilitate subsequently monitoring the pseudoaneurysm P, e.g., to confirm that the material 27 has expanded to substantially fill the pseudoaneurysm P.
Although the above methods describe treatment of a pseudoaneurysm, the apparatus and methods described herein for other medical treatments may also be contemplated. For example, the apparatus 10 may be inserted in a bodily tissue region where it is desired to embolize or occlude a vessel, or to reduce blood flow to a region, such as aneurysm sites, arteriovenous malformations, uterine fibroids, and tumors. Additionally, pharmaceutical agents may also be combined with the material 27 to treat infected and/or diseased tissue regions, such as tumors, liver toxins, osteomyelitis, and other conditions in which pharmaceutical treatment is desired and the material 27 may be beneficial to and/or cooperative with such treatment.
While the invention is susceptible to various modifications, and alternative forms, specific examples thereof have been shown in the drawings and are herein described in detail. It should be understood, however, that the invention is not to be limited to the particular forms or methods disclosed, but to the contrary, the invention is to cover all modifications, equivalents and alternatives falling within the scope of the appended claims.
The present application claims benefit of co-pending provisional application Ser. No. 60/976,351, filed Sep. 28, 2007, the entire disclosure of which is expressly incorporated by reference herein.
| Number | Date | Country | |
|---|---|---|---|
| 60976351 | Sep 2007 | US |
