Patent Application
20160022292
All publications and patent applications mentioned in this specification are herein incorporated by reference to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference.
The following patent is herein incorporated by reference in its entirety: U.S. patent application Ser. No. 11/969,827 titled, “ENDOLUMINAL FILTER WITH FIXATION” filed on Jan. 4, 2009.
Embodiments of the invention relate generally to devices and methods for retrieving or manipulating objects within a lumen. More specifically, embodiments of the invention relate to devices and methods for retrieving or manipulating medical devices from a body lumen and use of an ultrasound transducer to assist with navigation of the device.
Embolic protection is utilized throughout the vasculature to prevent the potentially fatal passage of embolic material in the bloodstream to smaller vessels where it can obstruct blood flow. The dislodgement of embolic material is often associated with procedures which open blood vessels to restore natural blood flow such as stenting, angioplasty, arthrectomy, endarterectomy or thrombectomy. Used as an adjunct to these procedures, embolic protection devices trap debris and provide a means for removal for the body.
One widely used embolic protection application is the placement of filtration means in the vena cava. Vena cava filters (VCF) prevent the passage of thrombus from the deep veins of the legs into the blood stream and ultimately to the lungs. This condition is known as deep vein thrombosis (DVT), which can cause a potentially fatal condition known as pulmonary embolism (PE).
The next advancement in filters added the element of recoverability. Retrievable filters were designed to allow removal from the patient subsequent to initial placement. These filters can incorporate retrieval features that can be grasped and/or secured by a retrieval device, such as a snare based retrieval device. Grasping the retrieval feature using a snare generally requires the user to manipulate the snare over the retrieval feature, which can be difficult due to a variety of factors, such as retrieval feature geometry and location within the lumen, the structure and properties of the snare, and ability to visualize the retrieval feature and/or snare using a real-time visualization technique such as fluoroscopy.
Accordingly, it would be desirable to have an improved retrieval device that would facilitate engagement with a retrieval feature on a device making retrieval and/or manipulation of the device easier and faster to complete.
The present invention relates generally to devices and methods for retrieving or manipulating objects within a lumen. More specifically, embodiments of the invention relate to devices and methods for retrieving or manipulating medical devices from a body lumen.
One embodiment of the present invention provides a novel and improved retrieval snare. The snare includes a snare wire, having a distal end and a proximal end, for use in the human anatomy, such as but not limited to blood vessels, pulmonary airways, reproductive anatomy, gastrointestinal anatomy, and organs such as the bladder, kidneys or lungs. The device enables a user to capture a foreign object located within the human anatomy, grasp said object in a controlled manner, and retrieve and remove said object from the human anatomy. Examples of foreign objects which might be removed from the human anatomy include implants such as stents, guidewires, leads, sheaths, filters, and valves, and organic objects such as kidney stones or calcified emboli. Other areas where embodiments of the snare can be used include, for example, removal and/or repositioning of distal protection devices that are used in a variety of medical procedures such as carotid stenting and percutaneous aortic valve replacement; and abdominal aortic aneurysm and thoracic aortic aneurysm devices. For example, a snare can be used to capture a vena cava filter and pull it into a retrieval sheath for removal from the patient. The snare is advanced through one or more retrieval sheaths, up to the site of a deployed filter. The snare is then deployed into the vessel, and engaged with the filter. Finally, the snare is held under tension while the sheath is advanced over said filter, collapsing it into the ID of said sheath. Another example is the use of a snare to grasp and extract loose kidney stones from a patient's kidneys. The snare is advanced through one or more sheaths, up to the site of the loose kidney stone. The snare is then deployed and engaged with the stone. Next, the snare is pulled into the sheath, drawing the stone into the distal ID of said sheath.
In some embodiments, a system for retrieving an object from a lumen is provided having a retrieval snare and an ultrasound transducer to assist in the intravascular navigation of the device. The system includes a retrieval device having a sheath configured to fit within the lumen, the sheath having a proximal end and a distal end. The device also includes a snare slidably disposed within the sheath, with the snare having a shaft with a longitudinal axis, a proximal end and a distal end and a plurality of loop elements in connection with the distal end of the shaft. The device further includes an intravascular ultrasound transducer located on the distal end of the sheath or shaft. A user interface configured to receive input from an operator regarding a surgical procedure including an insertion site and a destination site is also includes, as is a display. The device further includes a processor programmed to receive input from the user interface regarding the surgical procedure, determine anatomical landmarks between the insertion site and the destination site, receive an intravascular ultrasound signal from the intravascular ultrasound transducer, process the intravascular ultrasound signal into an image, and send the image to the display.
In some embodiments, the processor is further programmed to identify any anatomical landmarks in the image and tag the anatomical landmarks in the displayed image.
In some embodiments, the processor is further programmed to determine a location of the retrieval device based on the identified anatomical landmarks in the image.
In some embodiments, the processor is further programmed to determine whether the location is the destination site.
In some embodiments, the processor is further programmed to send a visual indicator to the display when the location has been determined to be the destination site.
In some embodiments, the visual indicator is color coded.
In some embodiments, the processor is further programmed to determine an orientation of the retrieval device with respect to anatomical landmarks using the processed intravascular ultrasound imaging signal.
In some embodiments, the processor is further programmed generate instructions for adjusting the position of the retrieval device based on the determined orientation of the retrieval device.
The novel features of the invention are set forth with particularity in the claims that follow. A better understanding of the features and advantages of the present invention will be obtained by reference to the following detailed description that sets forth illustrative embodiments, in which the principles of the invention are utilized, and the accompanying drawings of which:
As illustrated in
The loop elements 18 can have a region of overlap 31, with a span L1, between the adjacent loop elements. In some embodiments, L1 can be less than about 5, 10, 15, 20, 25, 30, 35, 40 or 45 degrees. In some embodiments, L1 can be between about 0 to 45 degrees, or about 0 to 15 degrees. The span of radial or circumferential coverage by each loop element 18 can be defined by the angle α between the two spoke elements 30 of the loop element 18, as shown in
The shape and flexibility of the loop elements 18 allows them to collapse and/or fold down easily into, for example, a 7Fr or smaller sheath catheter 22 during loading of the device 10 into the sheath 22 and/or during deployment of the device 10 from the sheath 22 and retraction of the device 10 into the sheath 22, as illustrated in
In some embodiments, as illustrated in
In some embodiments, the distal tip portion 32 of the sheath 22 can be radiopaque and/or include a radiopaque marker. For example, in some embodiments, the polymer forming the distal tip portion 32 can be doped with radiopaque elements or compounds, such as barium, tantalum, tungsten, palladium, platinum or iridium based compounds or elements. Alternatively or in addition to the radiopaque doping, a single or plurality of radiopaque markers, such as a radiopaque marker band made of the radiopaque elements or compounds described herein, can be incorporated into the distal tip portion 32. In some embodiments, the radiopaque marker band can be offset approximately 1-10 mm, or about 3-mm from the distal end of the sheath 22, so as to not interfere with the elasticity and eversion of the distal tip portion 32 during the capture process. The radiopaque doping and/or marker allow the operator to visualize the location of the distal tip portion 32 of the sheath 22 during insertion, advancement, and positioning of the sheath 22 near the foreign object within the lumen. This allows the operator to accurately and precisely advance and position the tip of sheath 22 to the foreign object. In some embodiments where an outer sheath is combined with the retrieval sheath, each sheath can employ different radiopaque marker patterns to allow the operator to differentiate between the two sheaths fluoroscopically.
In addition, the marker offset can also function as an alignment feature which aids the operator in positioning the distal end of the sheath 22 in the proper location relative to the foreign object to be retrieved. For example, the foreign object can be a filter 40 with a frame 52, a plurality of anchors 50 on the frame 40 and a retrieval element 42 as illustrated in
In some embodiments, the shaft 12 is straight and can be made of polymeric or metallic material, for example. The shaft 12 can be made of a solid design such as a wire, but can alternatively be hollow to facilitate passage of secondary devices through a lumen in the shaft 12. The shaft 12 can be of a single wire or element, but can also be constructed of a plurality of wires or elements which can be braided, twisted or stranded into a single shaft 12. The shaft 12 provides a means by which the user can advance, manipulate, and retract the distal end 14 of the device to capture and remove a foreign object from the human body. Typically, the user manipulates the device 10 at the proximal end 16, which is typically outside of the human anatomy. By manipulating the shaft 12, the motion is translated to the distal end 14 of the device 10, which in turn causes the loop elements 18 to move within the human anatomy. This motion allows the loop elements 18 to catch on the foreign object to be removed from the body. Consequently, the shaft 12 can be designed to have sufficient stiffness, flexibility, pushability and torqueability to accomplish the functions described herein. In some embodiments, a single wire shaft can provide sufficient stiffness, flexibility, pushability and torqueability. In other embodiments, a multiple wire shaft can provide sufficient stiffness, flexibility, pushability and torqueability.
In some embodiments, a hypo tube 20 attaches the loop elements 18 to the shaft 12. The hypo tube 20 has an inner diameter and an outer diameter, and is typically sized such that the shaft 12 and all of the loop elements 18 can fit within the inner diameter of the hypo tube 20. The inner diameter is sized such that there is adequate interference between the hypo tube 20 and the shaft 12 and the loop elements 18, so that the hypo tube 20 can be swaged or crimped circumferentially, mechanically locking the loop elements 18 and shaft 12 together. Additionally, the hypo tube can be radially shaped into a non-circular shape, such as but not limited to a hexagon or square or other rectilinear shape, to further facilitate mechanical fit and locking of said shaft 12 and loop elements 18. In some embodiments, the length of the hypo tube 20 is about at least two times its outer diameter, but can be as short as one times its outer diameter, or as long as twenty times its outer diameter. The loop elements 18 can also be attached to the shaft 12 via welding, soldering, capturing within a coil, or potting within a polymeric or rigid adhesive form, for example.
In some embodiments, the loop elements 18 have a geometric shape which allows them to deploy in a staged manner, where the shape and effective diameter of the snare 10 is dependent upon how far the snare 10 is deployed out of the sheath 22. In a first deployment stage as shown in
To facilitate engagement of the loop elements 18 with the retrieval element, the loop elements 18, when fully deployed, can be sized to conform approximately to the inner diameter of the lumen in which the foreign object is located. This allows full or substantially full apposition between the loop elements 18 and the full circumference of the lumen wall, which enhances the ability of the snare 10 to capture the retrieving element. In some embodiments, the geometry of the fully deployed loop elements 18 can be substantially elliptical, oval or oblong in order to conform to a lumen with a substantially elliptical, oval or oblong cross-sectional geometry. In these embodiments, the major axis of the elliptical or oblong geometry can be sized to conform approximately to the inner diameter of the lumen in which the foreign object is located. In general terms, the geometry of the fully deployed loop elements 18 can substantially match the geometry of the lumen.
For example, the vena cava may have a generally elliptical or oblong cross-sectional geometry. For use in the vena cava, a snare 10 with loop elements 18 having a substantially elliptical or oblong fully deployed configuration can be used advantageously, as shown in
In some embodiments, each individual loop element 18 can employ a single or plurality of radiopaque markers 56, such that each loop element 18 has a different quantity of radiopaque markers 56, or a different pattern of radiopaque markers 56, to allow the operator to visually differentiate and identify each loop element 18 fluoroscopically, as shown in
In some embodiments, the loop elements 18 can be attached or connected together using a variety of techniques, as illustrated in
In some embodiments, the loop elements 18 can include a single or plurality of loop collapse facilitator 23 features, as shown in
In addition, the loop collapse facilitator 23 can be oriented in a variety ways. For example, the loop collapse facilitators 23 can be pointed or extend either in a distal direction, as shown in
The diameters of the wires can be 0.002″-0.007″ each. The wires can be tightly wound together, and then formed into a loop element 18 of the desired shape. The loop element 18 outer radiused edge portion 26 can be angled such that the span of the radiused edge portion 26 is at angle of between about 45 degrees and 90 degrees, relative to the axis of the shaft 12.
The loop element 18 of one embodiment, as illustrated in
In contrast, in some embodiments a snare 10 with fewer loop elements 18, such as two loop elements 18, can be more easily visualized using real time imaging techniques, thereby allowing the operator to accurately identify each loop element 18 and therefore efficiently manipulate the position and orientation of the snare with respect to the foreign object. The two loop element embodiment, as discussed above, can still be capable of achieving complete or substantial circumferential apposition with the lumen wall. In some embodiments with too few loop elements 18, such as a single loop element, the single loop element can be too floppy, and a floppy loop element 18 can be difficult to precisely manipulate and position, making grasping a small retrieval element on a foreign object more difficult.
The loop elements 18 have a geometry that enables them to catch easily on foreign objects in the human anatomy. In some embodiments as shown in
In some embodiments, the two straight spoke portions 30, which radiate from the central axis of the hypo tube to the outer radius of the radiused edge portion 26, are set at an angle α of about 90 degrees, for a snare 10 with four loop elements 18. In some embodiments, the angle α between the two straight spoke portions 30 can be less than 90 degrees when, for example, the snare 10 has more than four loop elements 18, such as an angle of about 60 degrees for a snare 10 with six loop elements 18, or an angle of about 72 degrees for a snare 10 with 5 loop elements. To generalize, in some embodiments, the angle in degrees between the straight spoke portions 30 can be determined by dividing 360 by the number of loop elements 18 in the snare 10. This results in a configuration where the loop elements 18 cover an entire circle of space when viewed along the axial axis. Therefore, in an embodiment of the snare 10 with three loop elements 18, the angle between the two straight spoke 30 portions can be about 120 degrees. In some embodiments, the angle α between the straight spoke portions 30 can be greater than as determined using the formula set forth above, which results in an overlap of portions of the loop elements 18 with adjacent loop elements 18. In some embodiments, the angle between the two straight spoke 30 portions is greater than the value calculated in the formula set forth above, where an angle of about 5 to 15 degrees ensures that there is minimal or no gap about the perimeter of the snare, to form a closed circle.
In some embodiments, from a transverse view, the large radiused edge portion 26 of the loop element 18 can be angled between about 90 degrees and about 30 degrees relative to the axis of the shaft 12 of the device 10, as shown in
In other embodiments, from a transverse view, the large radiused edge portion 26 of the loop element 18 can be angled at an angle f3 that is from about 5 to 45 degrees relative to the longitudinal axis L of the shaft 12 of the device 10, as shown in
In these embodiments, the axial deployment length at full deployment of the loop elements 18 is relatively short when compared to some prior art devices which resemble the intermediate deployment configuration illustrated in
In addition to the axial deployment length, loop elements of prior art devices lack substantially complete circumferential apposition with the vessel wall, which makes it difficult to retrieve objects near the periphery of the blood vessel lumen. In contrast, embodiments of the snare disclosed herein achieve substantially complete circumferential apposition which facilitates retrieval of objections, such as retrieval elements on filters, that are located near the periphery of the blood vessel lumen.
One alternate embodiment of the device 10, illustrated in
In some embodiments, the loop elements 18 can be attached to a shaft 12 via a swaged or crimped hypo tube 20. These loop elements 18 can be made of two or more wires, including at least one Nitinol wire and at least one platinum wire. As illustrated in
Another alternate embodiment, as illustrated in
In some embodiments, this design offers several key features and capabilities, for example:
1. Loop Design
The design of the loop elements allows for deployment in different size lumens, and can conform to variations in lumen anatomy such as tapering, curvature, and angulations. This conformance feature can also enable the device to achieve full radial apposition with the target lumen regardless of lumen diameter or circularity. The loop configuration allows the device to catch a foreign object no matter where the object is located within the luminal space, since the loops reach full radial apposition within the lumen. The design of the elements allows the snare to fit into a very small guiding sheath, facilitating navigation through tortuous anatomies. The angled design of the loop radius allows the device to have axial reach both distal and proximal to the point where the loops are attached to the shaft, enabling the loops to locate foreign objects with minimal forward and backward axial manipulation of the device by the user. The non-angled design of the loop radius allows the device to have a flat, single plane circle geometry, enabling the loops to locate foreign objects with which may be against the vessel wall or partially embedded in the vessel wall. The loops can be made radiopaque, which allows visualization of the loop under fluoroscopy. Additionally, each individual loop element can employ a single or plurality of radiopaque markers such that each loop element has a different quantity of radiopaque markers, or a different pattern of radiopaque markers, to allow the operator to visually differentiate and identify each loop element fluoroscopically.
2. Shaft Design
The diameter and mechanical properties of the shaft, such as tensile strength, stiffness and/or elasticity, allows the user to manipulate the loops easily, by transferring axial and torsional motion from the proximal end of the device down to the distal end of the device. The diameter of the shaft allows for it to fit within a small diameter guiding sheath. The diameter of the shaft provides tensile support and strength to allow for high forces that may be required for removing a foreign object from the human anatomy. The shaft can be either solid or hollow, allowing the passage of devices, such as a guidewire, through the shaft. The shaft can be of a single element such as a wire, or a construction of a plurality of elements which are braided or stranded together. The shaft can be of a radiopaque material, to facilitate fluoroscopic visualization.
3. Hypo Tube Design
The inner diameter of the hypo tube allows the loop wires and shaft wire to fit snugly within the inner diameter, to facilitate mechanical swaging, soldering, or crimping of said hypo tube, mechanically locking the elements together. The outer diameter of the hypo tube provides adequate wall thickness to allow mechanical swaging or crimping of the hypo tube to provide a strong mechanical attachment, without cracking the hypo tube. The hypo tube can be of a radiopaque material, to facilitate fluoroscopic visualization. Additionally, the hypo tube can be radially shaped into a non-circular shape, such as but not limited to a hexagon or square or rectilinear shape, to further facilitate mechanical fit and locking of the shaft and loop elements.
In some embodiments, the fundamental design elements which achieve these features include, for example: (1) a plurality of loop elements, which are attached to a shaft via a hypo tube; (2) loops which are designed to be flexible and radiopaque; (3) loops which can be collapsed within a guiding catheter, and deployed outside of the guiding catheter; (4) loops which can reach full circular apposition within the luminal space in a human body; (5) loops which are attached to a shaft distally, which extend laterally towards the wall of the vessel of a human body; (6) loops which are angled relative to the axis of the shaft, typically less than 91 degrees and typically greater than 1 degrees; (7) loops which employ an attachment that is typically a crimped or swaged hypo tube; (8) a shaft which is attached to the loops; (9) a shaft having a diameter allows it to fit within a small diameter guiding catheter; (10) a shaft which can be either solid or hollow; (11) a shaft made of a material which can be polymeric, or can be of a metal such as but not limited to nickel titanium; and (12) a shaft having a length designed to enable the user to position the loops at a desired location to remove a foreign object from a human body.
In some embodiments, the snare device 10 is designed for placement into a guiding sheath 22, being advanced through said sheath 22, deploying near a foreign object located within the human anatomy, capturing said object, and removing the object from the human anatomy. The shape of the loop elements 18 allows them to conform to the diameter of the vessel in which they are deployed into, allowing easier capture of the foreign body with less manipulation.
The device 10 enables a user to capture a foreign object located within the human anatomy, grasp said object in a controlled manner, and retrieve and remove said object from the human anatomy. Examples of foreign objects which might be removed from the human anatomy include implants such as stents, guidewires, leads, filters, and valves, and organic objects such as kidney stones or calcified emboli. For example, a snare 10 can be used to capture a vena cava filter and pull it into a retrieval sheath 22 for removal from the patient.
As illustrated in
As the sheath 22 is advanced over the filter 40, the flexible distal tip portion 32 of the sheath 22 can expand and invert over the filter 40, providing a ramp in which the filter 40 can be drawn into the sheath 22. In some embodiments, the inversion of the distal tip portion 32 can be initiated by contact with specific structures on the filter, such as the retrieval element and/or anchors on the filter frame. In some embodiments, the snare 10 can be retracted in the proximal direction while the sheath 22 is advanced in the distal direction to capture the filter 40 within the sheath 22. In other embodiments, the snare 10 can be retracted in the proximal direction while the sheath 22 is held relatively immobile, i.e. neither advanced nor retracted, to capture the filter 40 within the sheath 22. In some embodiments, the entire filter 40 can be retracted into or captured by the inner sheath.
Another example is the use of a snare 10 to grasp and extract loose kidney stones from a patient's kidneys. The snare 10 is advanced through one or more sheaths 22, up to the site of the loose kidney stone. The snare 10 is then deployed and engaged with the stone. Next, the snare 10 is pulled into the sheath 22, or the sheath 22 advanced over the snare 10, drawing the stone into the distal ID of said sheath 22.
As described above, the retrieval system can include a plurality of different components, such as a guide wire, a snare 10, an inner sheath and an outer sheath 22. The proximal ends of these components are generally located outside the patient's body so that the operator can manipulate each of the components by grasping the proximal portion of the components and moving the component in a proximal or distal direction. Often, the proximal portions or ends of the components are or can be reversibly secured or fixed to one another in a proximal handle portion, using a rotatable or twist fitting, such as a luer lock, for example. Because one hand of the operator is often used to manipulate the component, only one hand is free to disconnect or connect the fittings, which can be difficult to do for a rotatable luer lock fitting. In addition, the twisting or rotation of the twist fitting can lead to unintentional and undesired twisting or rotation of the snare device.
Therefore, it would be advantageous to provide fittings that can more easily be manipulated with one hand, such as a snap fitting, as illustrated in
These snap fittings 100 can be integrated into the proximal ends of the various components described herein, and well as other components that can be used with the retrieval system. Alternatively, the snap fittings 100 can be made into luer lock adaptors, or other connector adaptors such as screw adaptors, that allow the operator to convert a luer lock fitting, or other fitting, into a snap fitting, as illustrated in
In some embodiments, the proximal gripping portions of the components can include an indicator that identifies which component the operator is gripping, thereby reducing the confusion that can occur in locating the corresponding proximal gripping portion for the desired component. In some embodiments, the gripping portion can include a visual indicator. For example, the different components can have color coded gripping portions, or can be labeled with, for example, an easily read symbol or the name of the component. In some embodiments, the gripping portion can include a tactile indicator that allows the operator to distinguish between the different components without having to look at the gripping portions, which allows the operator to maintain visual focus on more important matters, such as real-time imaging of the retrieval system within the patient provided through fluoroscopy. For example, one component can have a smooth gripping portion, another component can have a rough or knurled gripping portion, and another component can have a dimpled or ridged gripping portion. Each component can have a different tactile pattern to provide tactile contrast between the components.
Retrieval Device with IVUS and Pressure
In some embodiments, a pressure sensor and/or an intravascular ultrasound (IVUS) transducer can be added to or incorporated into the delivery system and method. The pressure sensor can be used to measure the pressure at various positions within the vasculature, which can be used to determine blood flow, while the intravascular ultrasound (IVUS) transducer can be used to measure fluid flow and/or provide imaging within the vessel. In some embodiments, the pressure sensor and/or IVUS transducer can be incorporated into the guidewire at one or more locations, such as the distal end or distal portion of a guidewire, as described in U.S. Pat. No. 8,277,386, U.S. Pat. No. 6,106,476 and U.S. Pat. No. 6,780,157 which are hereby incorporated by reference in their entireties for all purposes, as well as being incorporated into intermediate and proximal portions of the guidewire. The guidewire with the pressure sensor and/or the IVUS transducer can be used much like a normal guidewire to help navigate the delivery device through the vasculature, with the added benefit of providing pressure measurements and ultrasound imaging to help in the navigation, to visualize the device placement site, and to monitor and ensure proper device deployment. In some embodiments, the IVUS transducer generates image slices as it is advanced and retracted which can then be assembled together to form a three dimensional reconstruction of the vasculature and/or the device within the vasculature. In some embodiments, the guidewire with the pressure sensor and/or IVUS transducer can be fastened to a catheter in a similar manner to that described below for a catheter having a pressure sensor and/or IVUS transducer that is fastened to another catheter.
In some embodiments, the pressure sensor and/or IVUS transducer can be located on a catheter in a similar configuration to the guidewire. For example, the IVUS transducer can be located on the distal tip of the catheter while the pressure sensor(s) can be located proximally of the IVUS transducer at one or more locations along the catheter body, from the distal portion of the catheter to an intermediate portion of the catheter to the proximal portion of the catheter. The pressure and/or imaging catheter can be used in parallel with the delivery or retrieval device or any other catheter that is inserted into the vasculature. In some embodiments, the pressure and/or imaging catheter can be fastened to the delivery or retrieval device or other catheter by, for example, enclosing both catheters in a sheath or larger catheter or by fusing the two catheters together. For example, U.S. Pat. No. 6,645,152 and U.S. Pat. No. 6,440,077, both to Jung et al. and hereby incorporated by reference in their entireties for all purposes, discloses an intravascular ultrasound catheter joined together in parallel with a vena cava filter delivery device to guide placement of the filter in the vena cava. The pressure and/or imaging catheter can be used for the same purposes as the pressure and/or imaging guidewire.
In some embodiments as illustrated in
Use of the ultrasound imaging system allows the operator to deliver the device without fluoroscopy or using less fluoroscopy, thereby reducing the radiation exposure to the patient, while allowing more accurate evaluation of the vasculature, aiding placement of the device and allowing confirmation that device placement was proper. The imaging can be used to aid in the deployment of the filters or other devices. The imaging can also be used to aid in the retrieval of the deployed devices by providing visualization of, for example, the retrieval features on the deployed device and of the retrieval features, such as loops on a snare, of the retrieval device. The vasculature and implant location can be imaged prior to deployment, after deployment and/or during deployment. The imaging can be used during the retrieval process. The imaging can be used to aid in positioning of the filter or device within the vasculature. The imaging can be used to image the deployment location and determine the appropriate sizing of the filter or other device. The imaging can be used to help estimate treatment duration.
Although an imaging systems described above have been ultrasound based, other imaging systems can be used instead or in addition. For example, the imaging system can be based on intravascular ultrasound (IVUS), Forward-Looking IVUS (FLIVUS), optical coherence tomography (OCT), piezoelectric micro-machined ultrasound traducer (PMUT), and FACT.
Imaging System and Method for Navigation
One or more imaging modalities can be used to assist the navigation of the catheter and/or retrieval device through the vasculature and to assist in the surgical procedure at the surgical site. For example, fluoroscopy can be used to determine the location of the catheter and/or retrieval device in the vasculature and to assist in navigation. However, fluoroscopy involves the exposure of the patient to x-rays, which over time may increase the risk to a variety of diseases such as cancer, and may also cause burns to tissue such as the skin. The long procedure times for some operations can exacerbate these problems. In addition, medical personnel can also be exposed to incidental x-rays. Although the incidental exposure to the medical personnel is much lower than the patient during a given procedure, the numerous procedures using fluoroscopy conducted by the medical personnel during the course of the year can result in significant x-ray exposure to the medical personnel over time.
Therefore, the use of an additional or alternative imaging modality, such as intravascular ultrasound (IVUS) imaging, can be used to assist in navigation and assist in the surgical procedure at the surgical site, which can allow the use of fluoroscopy to be reduced, thereby lowering the x-ray exposure to both the patient and medical personnel. Another imaging modality that can be used is optical coherence tomography (OCT). Although the following embodiments have been described primarily using IVUS imaging, OCT imaging can be used by adding a fiber optic element and optical sensor to the catheter.
The multiple imaging modalities can generate different images that can be displayed separately on one or more displays and/or overlayed and combined or coregistered into a single image and for display on a single display.
In some embodiments, the imaging devices can be in communication with a computer system having a processor for executing instructions and software, memory for storing the instructions and software, one or more input devices such as a keyboard and mouse, and a display.
For example, the software can be imaging software that is designed for use to assist in various surgical procedures. For example, the imaging software can include a representative digital model of the cardiovascular system that includes all the blood vessels and the structures of the heart. In addition, the software can include a list of standard surgical procedures and allow the creation of custom surgical procedures, which can be a modification of the standard surgical procedures or can be created from scratch. The surgical procedures in the software contain information regarding the insertion site, the path of travel through the vasculature, the destination, and information regarding the performance of the procedure itself. For example, the surgical procedure can be linked to various instructions for use (IFU) associated with the devices used in the procedure. Also, given a particular insertion site and destination, the imaging software can anticipate the pathway through the vasculature that the surgeon will likely navigate and can determine the anatomical landmarks between the insertion site and destination site, as shown in step 3802. For example, the software can identify the vessel junctions that the guidewire, catheter, guide sheath, or other device will encounter and pass as it is advanced from the insertion site to the destination.
The software can also have information regarding the device and/or implant, such as the size and shape of the device and/or implant, the echogenic markings on the device and/or implant, the fluoroscopic markings on the device and/or implant, and the like. In one aspect, the various markings on the device and/or implant may be adapted and configured as an identification designation. In one embodiment, the identification designation includes a color designation selected by the user of provided by the system. For example, one or more markers in a distal portion of may be in a first color, a mid-portion may be in a second color and in a proximal portion in still a third color. In contrast to designating regions of the device and/or implant, the user or the system may designate individual markers each with a different color or grouped into zones of color. In still another aspect, the entire model or representation of the implant or device or portion thereof may be in color to permit easier identification in the navigation display. In still other embodiments, the color of all or a portion of the device/implant or the color indicated for one or more markers is determined by whether or not the device/implant or marker is in a proper or expected position or in an improper or unexpected position. In one embodiment, proper or expected positions may display as green, improper positions as red and unexpected or indeterminate positions as yellow. In each of the above examples, colors are exemplary of a kind of identification designation and other indicia such as numbers, letters, pictograms (e.g., check marks, X, thumb up, thumb down and the like) may be used.
The software can also have information regarding the delivery device and/or retrieval device including whether the delivery device and/or retrieval device is equipped with one or more IVUS transducers, pressure sensors, and the like. In some embodiments, the imaging software can construct a two dimensional and/or three dimensional reconstruction of the patient's vasculature in real time using the acquired imaging data from the one or more imagining modalities, as shown in step 3804. For example, in steps 3806 and 3808, fluoroscopy, if used, can be used to construct an initial two dimensional reconstruction of the patient's circulatory system and vasculature between at least the insertion site and the destination site. In addition, echocardiography, such as trans-esophageal echocardiography (TEE) and trans-thoracic echocardiography (TTE), can be used to generate images and/or determine blood velocity and tissue velocity. An intravascular imaging modality, such as IVUS and/or OCT, can be used to generate a two dimensional and/or three dimensional reconstruction of the patient's circulatory system and vasculature as the imaging device is moved through the vasculature, as shown in steps 3810 and 3812. The images can have an included scale that allows the distance between the vessels and other anatomical markers to be determined. The imaging device can have an outside surface with length or distance markings that allow the surgeon to determine what length of the imaging device has been inserted into the patient. In addition, the outside surface of the imaging device can include a longitudinal line along its length that allows the rotational orientation of the device to be determined.
Imaging data can be acquired as the imaging device is advanced through the vasculature, and also while the imaging device is retracted in reverse. In some embodiments, it can be desirable to scan a portion of the vasculature one or more times, such as two or three times for example, in order to enhance the resolution and/or accuracy of the reconstructed image.
In some embodiments, the imaging software can detect the presence of vessel junctions and/or other landmarks. In addition, as stated above, given a particular insertion site and destination, the imaging software can anticipate the pathway through the vasculature that the surgeon will likely navigate, and therefore, the software can identify the vessel junctions and/or other landmarks that the guidewire, catheter, guide sheath, or other device will encounter and pass as it is advanced from the insertion site to the destination. In some embodiments, for each detected vessel junction or other anatomical landmark, the imaging software can preliminarily tag, assign or suggest the name of the detected vessel junction and/or other landmark, as shown in step 3814. The surgeon can accept the recommendation of the imaging software, or can override the recommendation by assigning a different vessel or landmark name to the detected vessel junction and/or other landmark. In some embodiments, the software can provide the recommended name along with one or more alternative names for the detected vessel junction and/or other landmark, and the surgeon can select the recommended name or alternative name with a single mouse click or keyboard click. The recommendations can be placed over the image of the detected vessel junction and/or landmark. In addition or alternatively, the surgeon can be provided a list of potential names identified by the imaging software that can be selected by the surgeon. The surgeon can click or drag the name on top of the detected vessel junction and/or other anatomical landmark. In addition, the surgeon can manually enter in a name for the vessel junction and/or anatomical landmark, if, for example, the name does not appear in the recommendation or list. As the surgeon confirms and locks in the names of each detected vessel junction and/or other anatomical landmark, the imaging software can reevaluate and update its recommendations. The recommendations from the imaging software can be based on the insertion site, the destination, the anticipated pathway through the vasculature, the length of the device that has been inserted into the vasculature, the flow rate of blood, the blood pressure, the vessel diameter, the distance between other vessel junctions and/or anatomical landmarks, and the distance from and/or relative position to a confirmed or locked vessel junction and/or anatomical landmark.
This imaging procedure involving the identification of the vessel junctions and/or anatomical landmarks can be done either as a preliminary step before the catheter, which can be or include the retrieval device described herein, is inserted, or can be done concurrently with a catheter that doubles as an imaging device. In some embodiments, the guidewire and/or guide sheath and/or the catheter can include an imaging device, such as an imaging IVUS transducer located at the distal portion or tip of the device. The identified vessel junctions and/or anatomical landmarks can assist the surgeon in navigation the device through the vasculature to the destination site.
In some embodiments, the destination site, or a plurality of destination sites, can also be imaged in detail to assist the surgeon in accurately placing the device in the vasculature. For example, the femoral vein, the renal veins, and the inferior vena cave, for example, can be imaged along with other branch vessels. The locations of the vessels, the size and shapes of the vessel openings, the spacing between the openings, and the junction between vessels can be imagined and determined by the system and method.
In step 3816, the location of the delivery catheter can be determined. In some embodiments, the system can determine the location of the delivery catheter and/or retrieval device using one or more of the following: identification of anatomical landmarks in a previous step, the length of the delivery device that has been inserted into the vasculature, identification by the user, and identification of the implant or object to be removed. If the delivery catheter and/or retrieval device is not at the destination site, the system and software can instruct the operator to advance, retract, and/or rotate the delivery catheter and/or retrieval device, as shown in step 3820, based on the determined location of the delivery catheter and/or retrieval device. After or as the delivery catheter and/or retrieval device is moved through the vasculature, the system again acquires IVUS imaging data, as shown in step 3810. As shown in
Imaging Systems and Methods for Device Deployment
In some embodiments, the software can further include a module for assisting in the deployment of the implant or device. As described above, the user can select a medical procedure from a list or menu, at either the prompting of the software, or by manually selecting the option from a menu.
Each preprogrammed medical procedure includes information regarding the standard procedure steps, including for example, the access points, the typical routes of navigation, the equipment required or recommended, and information regarding the echogenic implant, including models of the implant and color sections or other identification designations described above. The user can be presented with a plurality of fields which each present one aspect of the medical procedure. For example, one field can present access points and can present as a default the most common access point typically used in the medical procedure. If the user desires to use a different access point, the user can click on the access point field to select from a plurality of different predetermined access points, or can manually customize an access point by dragging a marker over a schematic drawing of the human body or a representation of the patient's vasculature generated by patient specific imaging data.
For a given procedure, the destination is generally known, and therefore, the navigation route through the vasculature can be determined by the system based on the access point and the destination, as described above.
Another field can allow the user to select the implant being used in the medical procedure from a predetermined list. The software can be preprogrammed with all the features of the various implants, including size, three-dimensional shape, location of echogenic features, pattern of echogenic features, and nature of the echogenic features. Additionally or optionally, one or more of the identification designations associated with the device may be preprogrammed or provided by the user such that the display information relating to the position, orientation or placement of an implant is provided according to the user's preferred color or other identification designation. Once the particular implant to be used is selected, the system will be able to automatically identify the implant and its location and orientation within the vasculature using one or more imaging modalities, such as IVUS imaging or FLIVUS imaging, by identifying the various features of implant in the ultrasound imaging data and mapping the data to a model of the implant that is prestored in the software database. By determining the three dimensional location of each of these features within the vasculature, the location and orientation of the implant or device within the vasculature can be determined. The output presented to the user may also be updated to include one or more of the device identification designations.
The imaging system can also be used to image the deployment or retrieval site and can automatically identify the anatomical structures of interest, such as the inferior vena cava and the renal veins. The system can provide real-time imaging and implant deployment guidance by imaging the implant throughout the deployment procedure, displaying the real-time images to the user that includes a reconstruction of the deployment site and the current implant location and orientation within the deployment site, the current retrieval device location and orientation, and by providing instructions or recommendations to the user to achieve correct device deployment. The real time display may also be updated to include one or more identification designations or changes to an identification designation depending upon the stage of the procedure, user actions or other factors.
For example,
When the delivery device is determined to be at the target deployment location, as shown in step 3906, the operator can be instructed to begin deployment of the device or implant. During deployment of the device or implant, the system and software can determine the relative position between the partially deployed implant or device with the deployment site using IVUS, as shown in step 3908. The system and method can then determine whether the implant or device is correctly deployed based on the previous determination in step 3908. If the system and method determines that the implant or device is not correctly placed, the system and method can instruct the user to adjust the position of the implant or device based on the relative position between the implant or device and landmarks at the deployment site, as shown in step 3912. The system and method then loops back to step 3908. This loop can continue until the system and method determines that the implant or device is correctly deployed, upon which the system and method can instruct the user to complete the deployment of the implant or device, as shown in step 3614. Optionally or additionally, one or more identification designations may be updated or altered depending on the result of the operator action, adjustments to the device or subsequent determination(s) of the system. When the delivery device is determined to be at the target deployment location, as shown in step 3906, the operator can be instructed to begin deployment of the device or implant. During deployment of the device or implant, the system and software can determine the relative position between the partially deployed implant or device with the deployment site using IVUS, as shown in step 3908. The system and method can then determine whether the implant or device is correctly deployed based on the previous determination in step 3908. If the system and method determines that the implant or device is not correctly placed, the system and method can instruct the user to adjust the position of the implant or device based on the relative position between the implant or device and landmarks at the deployment site, as shown in step 3912. The system and method then loops back to step 3908. This loop can continue until the system and method determines that the implant or device is correctly deployed, upon which the system and method can instruct the user to complete the deployment of the implant or device, as shown in step 3914.
In some embodiments, as illustrated in
In some embodiments, as illustrated in
In some embodiments, as illustrated in
In some embodiments, as illustrated in
In some embodiments, as illustrated in
As illustrated in
In some embodiments, the echogenicity of the loop elements 2608 can be increased by employing twists or braids of two or more wires to form the loops. In some embodiments, an echogenic material can be used to coat the loop elements 2608 and other parts of the snare. For example, various echogenic features as described below can be incorporated into the loop elements 2608 and any other feature of the retrieval system 2600. In addition, echogenic materials and features can be incorporated into the filter device, as described below, in order to enhance its retrievability under IVUS imaging.
Filters are more complex structures in contrast to the relatively simple designs found in catheters and needles. In a more complex device like a filter there is a need to identify specific portions within the device during some medical procedures. In addition, it would be advantageous as well to determine the orientation of the device including components within the device to one another (as used for determining deployment, retrieval and the various intermediate stages thereof) as well as the overall filter orientation to the surrounding lumen or vessel. In contrast to the conventional techniques using location of the tip or start or end of the entire length, a more complex structure such as a filter position, orientation or relative placement information would yield specific benefits. In some cases, aspects, portions or attributes of the overall filter or filter components or portions will enable more useful determinations about the filter in relation to the physiological environment. In one aspect, an intravascular ultrasound (IVUS) catheter and processing system or signal processing algorithm is used to confirm filter sizing selection, guidance for filter placement, filter implantation steps, filter and/or vessel measuring using IVUS before during and/or after steps to confirm sizing selection and fit is appropriate under the physiologic environment and for confirmation and/or documentation of proper sizing selection, placement, engagement or degree of engagement of fixation elements (if present), clot burden, orientation and/or deployment in a patient or physician medical record.
In one aspect, embodiments of the present invention are directed toward medical devices having a complex shape or that are configured to move from stowed to deployed configurations that may also have specific orientation and placement criteria for proper use in a lumen, vessel or hollow organ. One such complex device is an IVC filter. Aspects of the present invention include such devices employed within the human body which have enhanced ultrasound visibility by virtue of incorporation of an echogenic material using any of the techniques described herein alone or in any combination.
In one aspect, there are described herein various alternative filter designs for increasing the echogenicity of the filter. A filter with enhanced echogenic characteristics may include one or more than one of: (a) a modification to one or more components of the filter to enhance the echogenic characteristics of the component; (b) formation of dimples into a component surface of sufficient number and scaled to a suitable size, shape, orientation and pattern for use with intravascular ultrasound systems; (c) protrusions formed in, placed on or joined to a filter surface; (d) roughening one or more surfaces of a filter, for example using a chemical process, a laser or bead blasting technique; and (e) altering one or more steps of a filter manufacturing technique to introduce cavities, voids or pockets to locally modify or adapt one or more acoustic reflection characteristics to improve echogenicity in one or more specific regions of a filter. One example of the manufacturing alteration is to introduce gaps between the segments of tubing or coverings whereby the gap provides the echogenic enhancement. In addition, cavities, voids, pockets, dimples, gaps and the like may be left empty or, optionally, filed, partially filed or lined with any of the echogenic materials described herein.
In one aspect, there are provided embodiments of a filter having enhanced echogenic characteristics in or related to at least one or a portion of: an proximal end, a distal end, a terminal proximal end, a terminal distal end, a retrieval feature, an atraumatic tip on a retrieval feature, a mid-strut region, a leg or strut portion having at least one orientation attribute to another portion of the filter, an indicia of a location of a fixation element or a retrieval feature, a location on a portion of the filter selected such that in use with a particular fixation element the marker in a location that indicates that the fixation element is fully deployed into a wall of a lumen or portion of a vessel or hollow organ (i.e., the marker is against the lumen wall or nearly so when the fixation element is fully engaged. As such, see the marker against the wall indicates proper deployment, spaced from or not visible would indicate, respectively, not fully engaged or over penetration); a portion of the distal tip and/or an elongated portion. The above described methods may also be applied to the other techniques and alternatives described herein.
In still further embodiments, a portion, component or aspect of an intraluminal filter may have enhanced echogenic attributes by applying a coating or sleeve containing one or more of the echogenic materials disclosed herein or fabricated according to any of the techniques or having any of the attributes to enhance echogenic qualities as described herein. In some aspects, the enhanced echogenic attributes are provided by the incorporation into, application onto or within a component or portion of a filter one or more echogenic materials or echogenic markers in a specific configuration, location, orientation or pattern on the filter.
Enhanced echogenic markers or locations may be devised and placed for use individually or in combinations such as to facilitate the identification to an IVUS system or ultrasound imaging modality an indication or signature for a specific location on a filter, such as, for example, a retrieval feature, a terminal proximal end, a terminal distal end, a location of a fixation element or a location of some other indicia that identifies a specific aspect of a particular filter design. In addition or alternatively, two or more enhanced echogenic markers or portions may be used in combination to provide additional information about a filter such as orientation with in a vessel, confirmation of deployment or a portion of a deployment sequence, confirmation of final placement, confirmation of migration or lack of migration, confirmation of retrieval or progress in a retrieval sequence and the like according to the various processes and used for filters within the vasculature or in lumens of the body. In another specific embodiment, the use of IVUS techniques with embodiment of the echogenic enhanced filters describe herein may also be used to measure the diameter of the vessel at specific device locations indicated by the echogenic markers during or after deployment or retrieval of a filter.
In still further aspects, the use of IVUS techniques with embodiment of the echogenic enhanced filters describe herein may also be used to determine, detect or indicate inadequate dilation, adequate dilation, filter expansion, degree of filter expansion, filter—vessel engagement and degree or engagement, strut/leg/anchor position and other attributes relating to the interaction between the filter and the surrounding physiological environment.
Still further, the echogenic markers are positioned with regard to the likely or planned positioning of the IVUS transducer and/or likely pathways for acoustic energy used by the imaging system. By way of example, if the IVUS transducer is forward looking, then those forward looking aspects of the filter will be provided with the enhanced echogenic aspects. In another example, if the IVUS transducer is cylindrically shaped and will be positioned through the interior portion of a filter then the filter will be provided with enhanced echogenic aspects on interior surfaces or portions that would receive acoustic energy from such as transducer in such a position. Other modifications are within the scope of the invention based on the particular style of IVUS transducer used, the position relative to the filter and the placement and type of echogenic feature incorporated into the filter. Put another way, the echogenic enhancements of the filters described herein are selected, designed and positioned on the filter with regard to the IVUS sensor type, acquisition mode and position relative to the filter. Additional details in the use of IVUS with filters is further described in U.S. Pat. Nos. 6,645,152 and 6,440,077, both of which are incorporated herein by reference in their entirety for all purposes.
In one aspect, the placement and signature of such enhanced echogenic markers are discernible to a human user viewing an ultrasound output alone or in combination with being discernible to a computer system configured for the processing of an ultrasound return including a return from the enhanced echogenic filter. Additional aspects of the formation and use of echogenic materials is made with reference to the following US Patents and Patent Publications, each of which is incorporated herein by reference in its entirety: US 2010/0130963; US 2004/0230119; U.S. Pat. Nos. 5,327,891; 5,921,933; 5,081,997; 5,289,831; 5,201,314; 4,276,885; 4,572,203; 4,718,433; 4,442,843; 4,401,124; 4,265,251; 4,466,442; and 4,718,433.
In various alternatives, the echogenic material may either be applied to a portion of or a component of a filter in any of a number of different techniques.
In one example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as a selective coating applied to a portion or component of a filter.
In one example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as a mold formed to be placed over or joined to a portion of component of a filter.
In one example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as an extruded sleeve formed in a continuous segment to cover a portion or component of a filter. In one embodiment, one of the inner tubular member or the outer sleeve or coating may be fabricated of a material according to the present invention, having increased echogenicity, with the other of the inner tubular member fabricated of a biocompatible polymer such as polyurethane or silicone rubber, for example.
In one example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as a compound or two layer structure comprising an inner tube and an outer tube or sleeve with one or both of the tubes made from or including or incorporating one or more echogenic materials or modifications as described herein. In addition or alternatively one or both sleeves, tubes described herein may include or encapsulate an echogenic marker or component of specific shape or geometry, for example, as in the case of a tube structure having within the sidewall of the tubing a coiled structure. In one aspect, the coiled structure is made from an echogenic material and the windings are provided in a manner that is useful in any of the aspects of the filter described herein. The coil may have a particular size or variation in size, pitch or variation in pitch or other attribute useful in providing an echo identifiable aspect of the filter property being determined. In one specific embodiment, the dimensions of the coil or other echogenic material has dimensions selected for increasing acoustic reflection with regard to the resolution or processing algorithms used in the imaging ultrasound system.
In one example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as a braided structure incorporated into a compound or two layer structure comprising an inner tube and an outer tube or sleeve with one or both of the tubes made from or including or incorporating one or more braid comprising echogenic materials or modifications as described herein. In addition or alternatively one or both sleeves, tubes described herein may include or encapsulate an braid formed into an echogenic marker or component of specific shape or geometry, for example, as in the case of a tube structure having within the sidewall of the tubing a braided structure. In one aspect, the braided structure is made from an echogenic material and the braided is a small diameter that is when wound around the tubes or sleeve or directly onto a portion of or component of a filter. The winding pattern and spacing of the braided materials are provided in a manner that is useful in any of the aspects of the filter described herein. The braid may have a particular braid strand composition, structure, size or variation in size, pitch or variation in pitch or other attribute useful in providing an echo identifiable aspect of the filter property being determined. One or more of the strands in the braid may be formed from an echogenic material. One or more of the strands may be formed from a material having improved radiopaque characteristic. One or more of the strands may be formed from a material having both echogenic and radiopaque properties. The strands of a braid may be combined using any of the above described strand characteristics.
In another alternative, in still another example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as the a series of short segments placed adjacent to one another along a portion or component of a filter in either a close packed or spaced arrangement. In another embodiment, the spacing or voids between adjacent segments may also be adjusted or selected so as to enhance echogenic capabilities of the filter using the material difference introduced by the spacings or voids.
In another alternative, in still another example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter as a tubing or sleeve suited to heat shrink operations. In one aspect, there is a manufacturing or assembly steps of sliding one or more sleeves over portion of the filter then apply heat to shrink down the segment about the portion of the filter. In particular, various embodiments provide for the specific placement of such a shrink fit tubing having enhanced echogenic characteristics as described herein. It is to be appreciated that the sleeves, segment or tubes may be provided from or have echogenic modifications or elements incorporated into suitable materials such as, for example, ePTFE, PTFe, PET, PVDF, PFA, FEP and other suitable polymers. Still further, these and other materials may be formed in shapes other than tubes but may also take the form of strands, lines, fibers and filaments to be applied in accordance with the echogenic enhancement techniques described herein. In some embodiments, the tubes or segments applied to a filter may have the same or different composition as well as have the same width or different widths. In one aspect, the width or thickness of a plurality of bands is used to provide a code or information about the filter. The use of echogenic bands of different widths is a marking technique similar to the way that different size and color rings on a resistor are arranged in a pattern to describe the resistor's value.
In another alternative, in still another example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter is extruded over a portion of or a component of the filter.
In another alternative, in still another example, an echogenic component or additive is applied to or incorporated into a filter or portion of a filter is by bonding an echogenic material or components to the filter using a suitable adhesive or bonding technique.
In any of the above described configurations, the portion or component of the filter may be modified with dimples, grooves, pockets, voids. In other aspects, there may be one or more full or partial circumferential recesses, rings, surface diffraction gratings or other surface features to selectively enhance or provide an echogenic property in that portion of the filter, to aid in or foster the application of the echogenic materials. In still further aspects, any of above described surface modifications may also be used to uniquely identify a portion of a filter or any of the above in any combination.
In still further aspects of any of the above echogenic markers or attributes the thickness of the sleeve or coating or component may decrease at its proximal and distal ends to provide for a smooth outer surface. As yet an additional alternative, a coating, marker or other echogenic material may extend proximally to or closely adjacent to the distal end or the distal end or both of the filter component or filtering device.
In still other alternatives or combinations, some filter design embodiments alter components of the filter to enhance echogenicity such as, for example, material selection to incorporate echogenic materials. Examples of echogenic materials include palladium, palladium-iridium or other alloys of echogenic materials.
In some embodiments, echogenic microbubbles are provided in a portion of a filter to enhance the acoustic reflections of that aspect of the filter. Echogenic microbubbles may be prepared by any convenient means and introduced into the component or portion thereof or by a coating or sleeve or shell or other transferring means or mixed with a polymer or other suitable base compound prior to extension of extrusion, molding casting or other technique. The echogenic microbubbles may be pre-prepared or prepared inside the component or element or marker as appropriate. Aspects of the preparation or use of microbubbles are described in U.S. Pat. Nos. 5,327,891; 4,265,251; 4,442,843; 4,466,442; 4,276,885; 4,572,203; 4,718,433 and 4,442,843. By way of example, echogenic microbubbles can be obtained by introducing a gas, e.g. carbon dioxide, into a viscous sugar solution at a temperature above the crystallization temperature of the sugar, followed by cooling and entrapment of the gas in the sugar crystals. Microbubbles can be formed in gelatin and introduced into a component or portion of a device. Microbubbles can also be produced by mixing a surfactant, viscous liquid and gas bubbles or gas forming compound, e.g. carbonic acid salt, under conditions where microbubbles are formed.
In still further alternatives, there is also the incorporation of dual mode materials (radiopaque and echogenic) into a polymer then used to form part of, be applied or otherwise incorporated with a filter device as described herein. Some of these polymer compounds may be fabricated to enhance aging and shelf life and have other beneficial attributes. In one aspect, a filter or portion thereof includes one or more selected segments that are constructed using visibility materials compounded with one or more polymeric materials that make the selected segments visible using both fluoroscopy and ultrasonic imaging. In one specific example, the visibility material may take the form of tungsten and/or tungsten carbide particles dispersed within a polymeric material. In one specific aspect, the radiopaque and echogenic material includes tungsten and/or tungsten carbide particles distributed within a base polymeric material.
In one embodiment, a portion of or a component of a filter includes or has been modified to have an inner layer including a radiopaque and echogenic material. In one alternative, the radiopaque and echo genic material includes particles distributed within a base polymeric material (i.e., a first polymeric material) including a polyether block amide; and an outer layer including an additional polymeric material (i.e., a second polymeric material). In certain embodiments, the additional polymeric material is a thermoplastic elastomer. Optionally, the additional polymeric material is more resistant to hydrolysis and/or oxidation than the base polymeric material.
In still further aspects, a component, a portion or an element added to a filter may be regarded as an echogenic body member that is a part of an echogenic filter to be sonically imaged. The echogenic body member is at least partially made up of a composite material which is echogenically imageable in the patient, such as by the use of ultrasonic imaging equipment used either within the patient or external to the patient. In one aspect, a composite material includes matrix material with discrete acoustic reflective particles embedded in matrix material. In one aspect, the matrix material is a biocompatible plastic. Examples of suitable plastics may include urethane, ethylene, silicone, polyethylene, tetrafluorethylene. In one aspect, a matrix is a formable, pliable material which may be molded and/or extruded to a variety of shapes, depending upon a specific application. The sound reflective particles are embedded in matrix material. Particles are, by way of example, made of a hard material, such as small glass particles that are solid or filled with an acoustically reflective medium. In one aspect, glass particles having a generally spherical shape forming glass microspheres. Glass microspheres with an outer diameter of about 5 microns is one acceptable size. Other sized particles may be utilized as, for example, ranging between 1 and 50 microns and beyond. Particles sized below the resolution size of the imaging ultrasound system in use may be arranged into patterns of sufficient size and orientation to the acoustic waves that result in a discernible feature by the imaging ultrasound system. Furthermore, the particles do not necessarily have to be spherical, or may be partially spherical. Still further, the shape of the particle could be altered to enhance acoustic reflection by presenting different shapes of particles, sizes of particles and combinations thereof to modify acoustic characteristics of the matrix material. By way of example, the particles may be shaped into an “Ordered array.” “Ordered arrays” can take the form of a macrostructure from individual parts that may be patterned or unpatterned in the form of spheres, colloids, beads, ovals, squares, rectangles, fibers, wires, rods, shells, thin films, or planar surface. In contrast, a “disordered array” lacks substantial macrostructure.
By way of example, an echogenic marker may comprise particles that individually are below the resolution of the imaging ultrasound system. The echogenic marker is the combination of these below imaging ultrasound resolution particles in combination, in 1D, 2D or 3D patterns, in graphic arrays, or in machine readable combinations to make a signature. Based on the specific characteristics of the combination of particles, the acoustic returns from an echogenic marker or combination of echogenic markers may be visually perceptible in a display for interpretation by a user or may be detected and interpreted by one or more acoustic reflection or spectral processing algorithms within a imaging ultrasound processing system.
In one aspect, the echogenic material is fabricated by incorporating nanometer sized particles of sonically reflective materials, for example iron oxide, titanium oxide or zinc oxide into a biocompatible polymer. In one method of fabrication, the acoustically reflective particles are mixed with a powdered thermoplastic or thermosetting material such as a polyether amide, a polyurethane or an epoxy, or polyvinylchloride followed by thermal processing of the mixture to provide a material of increased sonic reflectance which may be applied as a coating on medical devices of the type discussed above or may be incorporated as a structural component of the medical devices as described herein.
In still further embodiments and aspects, the particles included to provide echogenic enhancements may be selected, arranged or incorporated to provide acoustically geometrically tuned nanostructures, microstructures or macrostructures. The particles provided herein are formable in all shapes currently known or to be created for acoustic reflection enhancement. In non-limiting examples, the nano-, micro- or macro-particles are shaped as spheres, ovals, cylinders, squares, rectangles, rods, stars, tubes, pyramids, stars, prisms, triangles, branches, plates or comprised of an acoustically reflective surface or where one or more surfaces is adapted such as by roughening or dimpling or other technique used to alter acoustic reflection properties. In non-limiting examples, the particles comprise shapes and properties such as plates, solid shells, hollow shells, rods, rice shaped, spheres, fibers, wires, pyramids, prisms, or a combination thereof.
In one specific aspect, a partially spherical surface may be provided on the outside and/or the inside of particles, as for example a particle with a hollow spherical space therein. Particles are made up of a different material than the matrix. While desiring not to be bound by theory, it is believed that a spherical shape provides for sound reflections at a variety of angles regardless of the direction from which the ultrasonic sound waves are emanating from, and accordingly, are more likely to reflect at least a portion of the transmitted signal back to the ultrasonic receiver to generate an image. Since many of matrix materials available are relatively ultrasonically transparent in a patient, sound reflective particles provide adequate reflection. The use of a composite, rather than a solution, provides adequate size for acoustic reflection off of the discrete particles embedded in the matrix. As indicated, a variety of materials may be utilized for the sound reflective particles, such as aluminum, hard plastic ceramics, and, metal and/or metal alloys particles, and the like. Additionally, liquids, gases, gels, microencapsulants, and/or suspensions in the matrix may alternatively be used either alone or in combination, so long as they form a composite with the desired ultrasonically reflective characteristic.
Any of the above embodiments, alternatives or filter modifications to enhance echogenic characteristics may also be designed or implemented in such a way as to provide an echogenic identifiable or unique trait or acoustic reflection signature that may be registered by a human operator looking at a display or identified using signal processing techniques of a return containing acoustic reflections from the filter in an imaging ultrasound system. In one example, there is a surface of the filter having one or more echo registerable or identifiable feature, mark or indication in a position useful for determining one or more of: a location of an end of a filter; a location of a fixation element on a filter; a location of a retrieval feature on a filter; an orientation of one or more of a leg, a strut, a filter or an end of a filter relative to another of a leg, a strut, a filter or an end or the orientation of the overall filter to a lumen, vessel or hollow organ in a body. Moreover, in another widely applicable aspect of providing enhanced imaging characteristics to a filter as described herein, the characteristic or modification—however added or incorporated into the filter—enable a filter, a filter component or a specified portion of a filter to be more readily imaged by intravascular ultrasound as described herein. In still another aspect, the characteristics or modification to the filter are oriented and positioned in order to facilitate IVUS imaging via an IVUS probe borne by a filter deployment or retrieval catheter, snare, or other implement provided to facilitate the use of intravascular filters.
Also illustrated in
Echogenic characteristics may be added to each of the sections based on the type of function being measured or characterized. For example, echogenic markers, features or tags may be added to Section A in order to provide, for example: identification of the terminal end, end portion or retrieval portion of a filter. Echogenic characteristics of Section A may also be used for determinations related to Section A specifically or the filter generally of filter position, positioning, attitude within the lumen, localization of the filter within the vasculature and other traits common to the characterization of intravascular devices. For example, echogenic markers, features or tags may be added to Section B in order to provide, for example: identification of the mid strut portion, middle or capture region. Echogenic characteristics of Section B may also be used for determinations related to Section B such as for sizing, centering, symmetry of implantation, placement, apposition of implant to vessel walls, clot burden, deployment status or completion, gauge of filter capacity and/or filter contents as well as filter position, positioning, attitude within the lumen, localization of the filter within the vasculature and other traits common to the characterization of intravascular devices. For example, echogenic markers, features or tags may be added to Section C in order to provide, for example: identification of the rear portion, terminal end, retrieval feature, anchor location or depth of insertion, perforation indication or other aspects of the rear or proximal portion of a filter. Echogenic characteristics of Section C may also be used for determinations related to Section C such as for sizing, centering, symmetry of implantation or placement of legs struts and the like, as well as for determination of wall apposition, anchor penetration or perforation. Still further, the markers or tags may be added to aid in determining or evaluating filter position, positioning, attitude within the lumen, localization of the filter within the vasculature and other traits common to the characterization of intravascular devices.
A filter having enhanced echogenic properties is illustrated in
The filter 10 includes a plurality of elongated legs 16 which are of equal length and are identically configured to each other. The legs 16 are collectively arrayed in a conical geometric configuration so that the legs converge to the apical hub 14, and are symmetrically spaced about a central axis extending through the hub. Each of the legs is of equal diameter over its entire length and is made of a relatively resilient material, such as tempered stainless steel wire or the like. In addition to the echogenic attributes described herein, the legs may be coated with a polymeric, synthetic resin material having anti-thrombogenic properties.
In still other alternative embodiments, there is provided a material capture structure having one or more echogenic enhancements alone or in combination with radiopaque enhancements. In one aspect, the filter structure used in a filter includes both echogenic and radio opaque enhancements.
An one aspect, the filter includes material capture structure in the IVC filter will be viewable under fluoroscopic and ultrasound imaging modalities, including appropriate echogenic characteristics to enhance the view of the status or condition of the material capture structure while using IVUS. Enabling the material capture structure to be viewed will allow the physician to appropriately center and verify placement of a filter.
In one aspect, the filter elements or structures are doped to incorporate one or more of echogenic or radio opaque materials or treatments. In one aspect, the membrane, filaments or strands or other structures used to form the filter structure or webbing of the filter includes a radiopaque material having high echogenic properties, such as tungsten or gold, but not limited to either.
In other embodiments, one or more membranes, filaments or portions of a filament within a material capture structure includes one or more non-metallic echogenic features, such as those described elsewhere in this specification. For example, a membrane or filament or portion thereof may include air pockets either added to the material or by the use of materials with entrained air or gas that are used. Another example may include a membrane with a plurality of holes. In one embodiment, an ePTFE suture has echogenic properties due to air content of the ePTFE material. In other aspects, a suture material or a filament or polymer strand may also include dimpled/roughened/matrix/sponge materials, additives, or modifications to provide or enhance the overall echogenic nature of the suture, filament, material or material capture structure, in whole or in part.
In one aspect, these additional materials may assist the physician in centering or placing a filter within a vessel. In another aspect, this improvement is used in conjunction with IVUS will enable the adequate viewing of the filter portion of the filter and will allow for co-registration of filter placement along with an accurate entry/removal of the catheter through the webbing of the filter.
The advantages of this inventive aspect of a filter include, for example and not limitation, filter placement, accurate representation of filter location, ease of introducing/retracting catheter, more viewable space for more accurate assessments, ability to co-register filter location with IVUS and/or ability to better place filter in desired location.
Still other aspects of the use of the innovative filter include, for example, deployment of filters, positioning of filters, sizing of filters, and estimated treatment lengths as well as suture and/or material capture structure visibility. In still other aspects of the use of the innovative filter include, for example, deployment of a vena cava filter, positioning of an IVC filter, sizing of an IVC filter, and estimated treatment lengths as well as enhanced suture visibility.
In one embodiment, there is an IVC filter delivery system with an enclosed IVC filter. This filter would have a mesh, suture, web or other material capture structure suited to the anticipated filter use. The mesh, suture, web or other material capture structure has one or more components that is doped with a highly radiopaque material for better visibility under flouro and good echogenicity for better viewing under IVUS guidance. In still further alternative embodiments, the techniques described above may be applied to one or more material capture structure described in U.S. Patent Application Publication US 2008/0147111 entitled “Endoluminal Filter with Fixation” filed Jun. 4, 2008 as U.S. patent application Ser. No. 11/969,827, (the “'7111 publication”) incorporated herein by reference in its entirety for all purposes. In one particular aspect, the filament/strand/suture 461 shown in FIG. 58 of the '7111 publication may be coated or doped as described above alone or in combination with the illustrated pharmacological coating 466.
In some embodiments, the snare handle portion can include snare deployment indicators, such as detents, that allow the operator to easily identify and achieve the different stages of snare deployment described above. For example, the operator can deploy the snare using the snare handle until the snare handle reaches a first indicator, which signifies that the snare is deployed in the first deployment stage. The operator can then further deploy the snare using the snare handle until the snare handle reaches a second indicator, which signifies that the snare is deployed in the second or intermediate deployment stage. Then the operator can further deploy the snare using the snare handle until the snare handle reaches a third indicator, which signifies that the snare is fully deployed. In some embodiments, there is a snare deployment indicator for each stage of snare deployment. In some embodiments, the loop elements of the snare have different configurations in each of the different deployment stages as, for example, described above. For example, deployment indicators can be provided to allow the operator to deploy the snare in stages as described above with respect to
While described in various embodiments for retrieval of filters and other medical devices and objects, the sheath and snare designs may also be used to retrieve other filter devices, other embolic protection devices, and other objects. For example, filter devices and other devices described in commonly assigned, and concurrently filed U.S. Provisional Patent Application Ser. No. 61/586,661 (Attorney Docket Number 10253-701.102) is incorporated herein by reference in its entirety and for all purposes.
It is understood that this disclosure, in many respects, is only illustrative of the numerous alternative filtering device embodiments of the present invention. Changes may be made in the details, particularly in matters of shape, size, material and arrangement of various filtering device components without exceeding the scope of the various embodiments of the invention. Those skilled in the art will appreciate that the exemplary embodiments and descriptions thereof are merely illustrative of the invention as a whole. While several principles of the invention are made clear in the exemplary embodiments described above, those skilled in the art will appreciate that modifications of the structure, arrangement, proportions, elements, materials and methods of use, may be utilized in the practice of the invention, and otherwise, which are particularly adapted to specific environments and operative requirements without departing from the scope of the invention. In addition, while certain features and elements have been described in connection with particular embodiments, those skilled in the art will appreciate that those features and elements can be combined with the other embodiments disclosed herein.
This application is a continuation in part of U.S. patent application Ser. No. 14/777,224 filed on Sep. 15, 2015, which claims the benefit of PCT Application No. PCT/US2014/030392 filed on Mar. 17, 2014, which claims priority to U.S. Provisional Application No. 61/794,016 filed on Mar. 15, 2013. This application also claims priority to U.S. Provisional Application No. 62/052,406 filed on Sep. 18, 2014.
| Number | Date | Country | |
|---|---|---|---|
| 61794016 | Mar 2013 | US | |
| 62052406 | Sep 2014 | US |
| Number | Date | Country | |
|---|---|---|---|
| Parent | 14777224 | Sep 2015 | US |
| Child | 14858466 | US |
