Patent Application
20140121677
Embodiments disclosed herein relate generally to a medical device system including one or more fiducials and methods of use for same. More particularly, the disclosed embodiments pertain to handle mechanisms and systems including same for deploying fiducials, and methods of use for same.
Medical procedures often require locating and treating target areas within a patient. Focused, dose-delivery radiation therapy requires locating the target with a high degree of precision to limit damaging healthy tissue around the target. It is particularly important to know or estimate the precise location of the target in radiation oncology because it is desirable to limit the exposure of adjacent body parts to the radiation in a patient already suffering the depredations of cancer. However, in all treatment procedures, whether radiologic or otherwise, it is most desirable to be able to accurately target a region to be treated.
In many applications, it is not possible to directly view a treatment target or portion thereof (such as, for example, a cancerous tumor, cyst, pseudocyst, or other target) that needs to be acted on in some manner. As one example, when treating a lung or pancreatic tumor with radiation, it may not possible to view the actual tumor within the patient immediately before the radiation treatment. It is therefore highly advantageous to have some mechanism for permitting the tumor to be located accurately so that the radiation treatment can be targeted at the tumor while avoiding damage to healthy tissue.
Even for target regions that may be visualized using CAT (computer-assisted tomography) scans, MRI (magnetic resonance imaging), x-rays, ultrasound, or other techniques, difficulties often arise in targeting a treatment. This is particularly true for target regions within a torso of a patient and soft tissue regions. Due to the mobility of tissues in those regions (e.g., movement of internal organs during respiration and/or digestion, the movement of breast tissue with any change of body position, etc.), a target region may not remain fixed relative to anatomical landmarks and/or to marks that can be placed onto an external surface of a patient's body during one of those visualization procedures.
Several techniques have been developed to address this problem. One such technique is to place markers into the patient along the margins of the target region. The markers may be active (e.g., emitting some kind of signal useful in targeting a therapy) or passive (e.g., non-ferromagnetic metallic markers—called fiducials—that can be used for targeting under ultrasound, MRI, x-ray, or other targeting techniques, which may be included in a treatment device).
A fiducial is typically formed of a radio-opaque material that the target can be effectively located and treated with a device that targets a site using the fiducials as positional markers under radiographic detection. Typically, the fiducials may be inserted into the patient during a simple operation. Percutaneous placement is most commonly used. However, use of minimally-invasive placement via an endoscope has recently developed for fiducial placement into a patient's internal organs. For example, percutaneous placement of fiducials along the margins of a pancreatic tumor can be complex and painful (particularly for obese patients, where the needle size is necessarily larger). Another process using percutaneously implanted objects in a patient is brachytherapy. In brachytherapy, radioactive sources or “seeds” are implanted into and/or adjacent a tumor to provide a high dose of radiation to the tumor, but not the healthy tissue surrounding the tumor.
In a “pre-loaded configuration,” the seed/fiducial 110 is retained in the cannula 108 by a plug 112 made from bone wax or other suitable bio-compatible material(s). This is typically accomplished by a “muzzle-loading” technique where the fiducial is placed into the distal needle and then held in place by the bone wax plug. This can present some challenges, as the bone wax plug 112 can be visible as an artifact in the patient, potentially interfering with clear visualization of body structures or treatment devices. With this configuration, the cannula 108 must be withdrawn and reloaded after delivery of each seed/fiducial 110. If the target locations for the fiducials are very far apart, use of a single percutaneous introducer cannula/trocar for multiple introductions of the cannula 108 may not be possible. In such a circumstance, the patient must endure several percutaneous punctures (and the increased attendant risk of infection for each).
To implant the desired arrangement of seeds/fiducials 110 at a target location in a patient, an operator pushes the cannula 108 in a first direction (arrow A) to insert the tip 105 into the patient (typically under fluoroscopic visualization). The operator then pushes the second handle 103 further in the first direction to position the tip 105 at the desired depth within the patient where a seed/fiducial 110 is to be implanted. Throughout this motion, the operator moves the needle 102 and the stylet 104 together as a unit. At the desired depth/location, the operator grasps the first handle 101 with one hand and the second handle 103 with the other hand. Then, the operator holds the first handle 101 stationary while simultaneously sliding the second handle 103 back in a second direction (arrow B) toward the first handle 101. As shown in
As will be appreciated from the disclosed structure, after deploying one fiducial, one may alternatively reload the introducer 100 from the proximal end by completely withdrawing the stylet 104, then placing another fiducial into the needle lumen and advancing it therethrough to a second location to which the distal needle tip 105 has been directed (a “breech-loading” technique). Provided that the fiducial target sites are sufficiently close together to allow this technique, it can reduce the number of percutaneous punctures or other access procedures needed to place more than one fiducial. However, it creates a problem for procedures where ultrasound is being used or is to be used in the near-future because it introduces air pockets into the tissue and related fluids. Those air pockets with tissue and/or fluid are echogenic in a manner that can interfere with ultrasound visualization of a target area and/or tools being used to diagnose or treat in/around the area. In some brachytherapy techniques, a series of fiducials may be preloaded into the needle—either separately or connected by a suture or similar device—then placed together in fairly close proximity; however, such a technique typically is not effective for placing three or more fiducials in sufficiently disparate locations to use for targeting a treatment relative to, for example, margins of a tumor. This may also be true for multifiducial systems that rely upon a distal plug to retain fiducials, which are thereafter released freely, in contrast with systems according to the present invention, which are configured for controlled serial release (e.g., one at a time, two at a time, or some other user-controlled retention and release of a pre-determined number of fiducials).
The process is similar when implemented endoscopically in the manner developed rather recently, except that the needle and stylet are of the type known in the art for use through the working channel of an endoscope. One limitation of current endoscopic techniques is the size of fiducial that can be introduced. With the size limitation of endoscope working channels, the largest needle that can typically be used without risking bending, crimping, curving or otherwise damaging a needle (that does not have an internal stylet or other support) during advancement out of the endoscope to an anatomical target is a 19-gauge needle. This limits the size of the fiducial that can be introduced through the needle lumen using current, cylindrical fiducials. The endoscopic technique generally suffers from the same reloading problems as described above. Even though the external percutaneous punctures are not an issue, having to withdraw and reload takes up valuable time and complicates the procedure, potentially requiring additional personnel, whether only the stylet is withdrawn for “breech-loading” or the entire device is withdrawn for “muzzle-loading.”
It would be desirable to use ultrasound, and particularly endoscopic ultrasound (EUS) for navigation and placement of fiducials. As such it would be desirable to provide and use the largest possible fiducial that will provide improved echogenicity based on its size and echogenic profile. It would be desirable to provide multiple fiducials in a needle that can be introduced in a controlled serial manner (one, or some other pre-determined number, at a time) rather than requiring manual reloading after placement of each fiducial.
Embodiments of a fiducial deployment system described herein may include one or more of: one or a plurality of fiducials having one or more protuberances, a slotted needle configured for delivering a plurality of fiducials in serial fashion where the slot receives the fiducial protuberances without a detent that occupies any internal diameter needle lumen portion, a handle configured for controlling the serial delivery by user-operated deployment of a predetermined number of fiducials, and a method of delivering fiducials to a target region.
The terms “proximal” and “distal” are used herein in the common usage sense where they refer respectively to a handle/doctor-end of a device or related object and a tool/patient-end of a device or related object.
A variety of fiducial and needle configurations may be used in keeping with the present embodiments including those described in U.S. Pat. App. Publ. Nos. 2010/0280367, 2011/0152611 to Ducharme et al., 2013/0006101 to McHugo et al., 2013/0006286 to Lavelle et al., and 2013/0096427 to Murray et al.), each of which is incorporated herein by reference in its entirety (except that any definitions of terminology from the present application shall govern). One embodiment, illustrated with reference to
Such a fiducial 400 preferably will be formed of a radio-opaque, non-ferromagnetic material such as, for example, gold, platinum, palladium, iridium, or alloys thereof, with one preferred embodiment including an alloy of palladium with rhenium (advantages of which may include desirable radio-opacity, market-price stability superior to gold, and ultrasound-reflectivity/echogenicity due to density). Being radio-opaque will allow the fiducial to be used in deployment techniques using fluoroscopy, as well as making it detectible/visualizable by radiographic means during a treatment or other procedure where it may be desirable to know the location(s) of one or more fiducials. Being non-ferromagnetic will lessen the likelihood that visualization techniques or other procedures employing magnetic fields such as, for example, MRI, will re-orient or otherwise dislodge a fiducial. Echogenic construction of a fiducial or needle may be enhanced by surface texture, but can also be provided by structural inclusions such as embedded bubbles or beads that provide for a different ultrasound reflectivity than material surrounding them. Fiducials may also be coated with a material (e.g., parylene) configured to reduce backscatter during radiography.
In a preferred embodiment, the fiducial 400 is configured and dimensioned for passage through and release from a needle lumen. For an endoscopic delivery system, the fiducial body 402 (exclusive of the protuberance) preferably will have an outer diameter (OD) of about the same or less than the inner diameter (ID) of a needle lumen, but the OD of the fiducial body preferably will be no greater than the needle ID. As used herein, the OD of the fiducial refers to an imaginary circle (or other geometric shape) whose outermost boundaries all fit within the ID of the needle lumen. In other words, it is preferable that the fiducial is dimensioned to fit slidably into the needle lumen, except the protuberance, which projects into the slot.
The longer body portion distal of the protuberance can help make certain that, during deployment through a needle, a first fiducial distal of this second fiducial will be fully advanced out of the needle before that second fiducial is positioned for deployment, as will be made clearer with reference to
The fiducial 400 has a generally cylindrical body 402 formed as a mass with a generally circular transverse cross-section along its proximal and distal end sections. A protuberance 408 projects from the longitudinal circumferential face 406 of the fiducial body 402. As viewed from the top, the protuberance 408 is generally obround. The irregular shape and increased surface area (as compared to a typical cylindrical fiducial of the type used in plug-ended systems and/or systems with some type of lumen-occupying detent) preferably enhances the echogenicity of the fiducial, which preferably will already be desirably high due in part to its composition.
The protuberance 408 includes protuberance end faces 407 that may provide one or more of chamfered, filleted, and radiused transition to the outer face 406 of the body 402. The body 402 is generally a right cylinder, but for the protuberance 408. In this embodiment, the protuberance 408 is rounded and substantially parallel to the longitudinal central axis of the fiducial body, and it is about one half the length of the body 402, and it is centered along the body length. In a preferred embodiment, the fiducial 400 is configured and dimensioned for passage through and release from a needle lumen. For an endoscopic delivery system, the fiducial body (exclusive of the protuberance) will have an outer diameter (OD) of about the same or less than the inner diameter (ID) of a needle lumen, but the fiducial body OD preferably will be no greater than the needle ID. The protuberance 408 will engage and ride along through a needle slot.
Dimensions of one exemplary embodiment are also described with reference to
In the embodiment of
The body wall cannula 804 generally circumferentially defines a needle lumen 810 configured to allow sliding passage therethrough of a fiducial such as, for example, a fiducial (e.g., as shown in
An exemplary needle embodiment is also described with reference to
The distal end portion of a fiducial deployment system 1000 is described with reference to
The protuberance 408 of the distal-most fiducial 400 is captured against the tabs 808 of the needle 800. A stylet 1006 configured for use as a pusher is disposed through a portion of the needle lumen 810 and preferably is configured for actuation from the proximal end, whereby it can be used to distally advance/push out the fiducials and/or hold them in place as the needle is withdrawn from around them. The presence of the fiducials and stylet in the needle 800 preferably improve its columnar strength reduce the likelihood that it will get bent, crimped, or otherwise damaged as it is navigated through and out of the distal end of an endoscope working channel (not shown).
Several different handle embodiments may be used to effect advancement and release of one or more fiducials. Certain handle embodiments are described with reference to
A method of using the fiducial deployment needle of
The endoscope 1100 is shown in
As shown in
As will be appreciated from the structure of the needle 800 and fiducials 400 as shown in
The user preferably will have a tactile sense of resistance as the protuberance 408 passes through the tabs 808, which resistance will decrease immediately as soon as the protuberance clears the tabs. Then the user preferably continues the relative motion of stylet and needle until resistance is again encountered, indicating that the next fiducial behind the distal-most one has met the proximal tab edges 808a.
It will often be preferred that the fiducials (and the protuberances thereon) be proportioned such that complete deployment of a distal-most fiducial includes it substantially clearing the distal needle tip 802 and coincides with the protuberance of the next distal-most fiducial meeting the proximal tab edges 808a. As such, it may be advantageous in some fiducial embodiments to position the protuberance more proximally on the fiducial body such that a fiducial body portion distal of the protuberance is longer than a body portion proximal of the protuberance. It should be appreciated that the protuberance of almost any fiducial embodiment in keeping with principles of the present invention may be disposed near the proximal end up to and including flush with the proximal end of the fiducial body).
Next, the user may retract the needle 800 into the sheath 1002 to a sufficient distance allowing it to be re-extended to a second target site, where the procedure described above may be repeated. These steps may be repeated for placement of third, fourth, and further fiducials. As is known in the art, these fiducials may be used for “positive targeting” and/or “negative targeting” of a therapy such as radiation therapy (“positive targeting” indicating “treat here”, and “negative targeting” indicating “do not treat here”). The present system presents numerous advantages. For example, consider a patient already undergoing an endoscopy procedure to biopsy a located but undiagnosed tissue mass. The endoscopic biopsy can be taken and a tissue slide prepared immediately. If a diagnosis is made (in conjunction with whatever other data are available and pertinent) that the tissue mass will benefit from a treatment where placement of fiducials is indicated, the physician can immediately deploy fiducials in the manner described above.
The ability to complete the method using direct/video and ultrasound imaging with little or no use of fluoroscopy presents an advantage of minimizing the radiation exposure of the patient (who may, for example, have to undergo radiation therapies where the total amount of exposure to radiation is desired to be minimized to that which is therapeutically and diagnostically necessary). Advantages of time and expense for the patient, physician and other treating/diagnostic personnel, and the treatment facility are likely as implementation of the present method may prevent all of those entities from having to schedule and conduct a second endoscopic procedure, and/or to extend the initial diagnostic procedure with the time-consuming methods and materials currently available in the prior art as described. It should also be appreciated that, when informed by the present disclosure, those of skill in the art may utilize and/or adapt the presently-disclosed embodiments for percutaneous use while remaining within the scope of one or more claims.
Fiducials with generally cylindrical or otherwise generally regular geometry may migrate after having been placed in a desired location, including that—over the course of multiple treatments of a target area delineated by fiducials—they may migrate with changes in the condition of surrounding tissues. For circumstances where it may be advantageous to minimize migration, a fiducial may be used that includes one or more anchoring projections.
The sheath-attached handle member 1602 includes numerical indicia 1608 and an adjustable ring 1609 that limits the movement of the needle-attached handle member 1604 and provides a way to select the distance to which the needle 1614 may be extended beyond the sheath 1612. By way of illustration, the configuration shown in
A stylet 1610 extends through a lumen of the needle 1614 and has a stylet cap 1611 fixed on its proximal end. The stylet 1610 is shown as being retracted proximally in
The clutched gear handle component 1650 may include an actuation member 1670 and an elongate first handle member 1654 including and defining a central longitudinal axis. It may be attached to an elongate distal outer body having a longitudinal body lumen (e.g., in some embodiments, needle-attached handle member 1604, or—in other embodiments—a fiducial needle and/or sheath). A stylet 1660 (which may correspond to the stylet 1610) extends through at least a portion of the first handle member 1654 along or generally aligned with its central longitudinal axis.
An axle 1662 is mounted rotatably within the first handle member 1654, disposed adjacent to and transverse of the central longitudinal axis. A clutched gear 1664 is mounted rotatably to the axle 1662 by a one-way clutch bearing allowing unidirectional rotation of the clutched gear 1664 around the axle 1662. A drive gear 1666 is fixed to the axle 1662, such that the drive gear rotates with the axle, and that rotation can be unidirectionally actuated by rotation of the clutched gear 1664 in a first direction, while counter-rotation of the clutched gear in the opposite direction will not rotate the axle and drive gear. Those of skill in the art should appreciate that a ratchet/pawl mechanism may be adapted for use as a function equivalent of the clutched gear, within the scope of the present invention.
An actuation member, embodied in
A rack member 1676 is engaged and generally longitudinally aligned with the stylet 1660. A surface of the rack member 1676 mechanically communicates with a surface of the other of the drive gear 1666 or the clutched gear 1664 such that actuation of the actuation member 1670 is mechanically translated to unidirectional movement of the stylet 1660 via the rack and gears. The L-shaped lever 1670, the rack 1676, the drive gear 1666, and the clutched gear 1664 are shown in this embodiment as including at least one toothed surface, and the mechanical communication is provided by interengagement of at least two of the toothed surfaces. Other forms of frictional or mechanical engagement may be used to provide the mechanical communication.
The mechanical communication of the actuation mechanism 1650 may be configured such that a predetermined number of actuations of the lever 1670 will advance the stylet 1660 a lengthwise distance corresponding to dispensing a single fiducial 400 out of a distal end of a needle 1614. This is indicated in
Those of skill in the art will appreciate that actuation may user-perceptibly be indexed by visual indicia, tactile indicia, audible indicia, or any combination thereof, and that the indicia may be configured to correspond to a pre-determined longitudinal movement distance of the stylet by the rack(s). A variety of such indicia are known and well within the skill in the art, given the present disclosure. For example one of the rack elements may include numerals, colored bands, or other visual indicia made viewable through a side window in the handle body (e.g., 1658, 1684, 1984). Types of indicia may include those disclosed in U.S. Pat. No. 6,613,002, which is incorporated by reference herein (except, as those of skill in the art will appreciate, placed proximally on the stylet, one or more racks, and/or other components such that a user may easily observe the handle embodiment and determine the number of fiducials dispensed and/or the distance of stylet advancement). A numeric or other “counter” type of indicator may be provided, attached to an actuator element, the stylet, or other component and configured to indicate the number of fiducials that have been dispensed and/or the number of fiducials remaining. This includes those described in U.S. Pat. App. Publ. 2011/0152611, which is incorporated herein by reference in its entirety. Opposed detents on a static component and one or more moving elements (e.g., rack, stylet) may easily be included to provide tactile and/or auditory feedback in addition to providing information about the distance of stylet advancement and/or needle retraction associated with a particular actuation movement. A method of use may include actuation of the lever 1670 to advance the stylet 1660 for deployment of one or more fiducials in one or more locations. Because deployment of multiple fiducials in a single location/actuation is disfavored (due, for example, to “train-wreck” misalignment and a desire to minimize use of fiducial materials), preferred method embodiments will deploy only one fiducial at a time.
The clutched gear component 1680 may include an actuation member 1690 and an elongate first handle member 1684 including and defining a central longitudinal axis. It may be attached to an elongate distal outer body having a longitudinal body lumen (e.g., in some embodiments, needle-attached handle member 1604, or—in other embodiments—a fiducial needle and/or sheath). A stylet 1660 (which may correspond to the stylet 1610) extends through at least a portion of the first handle member 1684 along or generally aligned with its central longitudinal axis.
An axle 1683 is mounted rotatably within the first handle member 1684, disposed adjacent to and transverse of the central longitudinal axis. A clutched gear 1685 is mounted rotatably to the axle 1683 by a one-way clutch bearing allowing unidirectional rotation of the clutched gear 1685 around the axle 1683. A drive gear 1687 is fixed to the axle 1683, such that the drive gear rotates with the axle, and that rotation can be unidirectionally actuated by rotation of the clutched gear 1685 in a first direction, while counter-rotation of the clutched gear in the opposite direction will not rotate the axle and drive gear.
An actuation member, embodied in
A second rack member 1689 is engaged and generally longitudinally aligned with the stylet 1660. A surface of the second rack member 1689 mechanically communicates with a surface of the other of the drive gear 1687 or the clutched gear 1685 such that actuation of the actuation member 1690 (e.g., depressing the button 1692) is mechanically translated to unidirectional movement of the stylet 1660 via the racks and gears. The first rack 1694, the second rack 1689, the drive gear 1687, and the clutched gear 1685 are shown in this embodiment as each including at least one toothed surface, and the mechanical communication is provided by interengagement of at least two of the toothed surfaces. Other forms of frictional or mechanical engagement may be used to provide the mechanical communication.
The mechanical communication of the actuation mechanism 1690 may be configured such that a predetermined number of actuations of the button 1692 will advance the stylet 1660 a lengthwise distance corresponding to dispensing a single fiducial 400 out of a distal end of a needle 1614. This is indicated in
The clutched gear component 1980 may include a rotary actuation member 1992 and an elongate first handle member 1984 (the wall/housing of which is shown as longitudinally sectioned to expose the internal components) including and defining a central longitudinal axis. It may be attached to an elongate distal outer body having a longitudinal body lumen (e.g., in some embodiments, needle-attached handle member 1604, or—in other embodiments—a fiducial needle and/or sheath). The stylet 1960 (which may correspond to the stylet 1610) extends through at least a portion of the first handle member 1984 along or generally aligned with its central longitudinal axis.
An actuation member, embodied in
The drive gear 1987, shown in
In certain preferred embodiments, a predetermined incremental rotation of the knob 1992 will advance the stylet a distal longitudinal distance corresponding to the length of (and thereby the dispensing of) one fiducial or another predetermined number of fiducials. Those of skill in the art will appreciate that the predetermined incremental rotation may be one full turn, a partial turn (e.g., with visual, tactile, and/or auditory indicia such as “clicks”), or some other user-controllable increment that advances the stylet 1960 a desired distance. Those of skill in the art will appreciate that other forms of frictional or mechanical engagement may be used to provide the mechanical communication in addition to and/or other than the meshed-gear and threaded interface shown in
Those of skill in the art will appreciate with reference to the embodiments disclosed above that a predetermined number of fiducials may be released into a desired location by a single actuation of the lever, button, or other actuation member. The predetermined number preferably will be one, but may include a plurality of fiducials. The configuration of the present embodiments provide clear advantages over prior designs that utilize releasable end-plugs in a needle to retain fiducials, and/or that use less refined means of controlling the fiducial release than the notch/tab needle design and/or actuation handles described herein.
Drawings and particular features in the figures illustrating various embodiments are not necessarily to scale. Some drawings may have certain details magnified for emphasis, and any different numbers or proportions of parts should not be read as limiting, unless so-designated by one or more claims. Those of skill in the art will appreciate that embodiments not expressly illustrated herein may be practiced within the scope of the present invention, including that features described herein for different embodiments may be combined with each other and/or with currently-known or future-developed technologies while remaining within the scope of the claims presented here. For example, a needle and fiducials of the present system may be used percutaneously, including in another minimally invasive surgical procedure, such as a laparoscopic-type procedure, within the scope of the claimed invention. For example, a target site may be a location in or near the gastrointestinal tract (e.g., liver, pancreas) such as those locations that may be accessible by endoscopy (using a minimally invasive endoscope introduced through a natural patient orifice, e.g., mouth, anus, vagina). This includes—more broadly—sites reachable through NOTES (natural orifice translumenal endoscopic surgery) procedures. The present method and device may also be used with other minimally-invasive surgical techniques such as percutaneous endoscopic procedures (e.g., laparoscopic procedures) or percutaneous non-endoscopic procedures, but most preferably is used with less invasive endoscopy procedures. It is therefore intended that the foregoing detailed description be regarded as illustrative rather than limiting. And, it should be understood that the following claims, including all equivalents, are intended to define the spirit and scope of this invention.
This application is a non-provisional application which claims priority to U.S. provisional application Ser. No. 61/712,611, filed Oct. 11, 2012, which is incorporated by reference herein in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61712611 | Oct 2012 | US |
