Expandable tissue cavity marker devices, systems and deployment methods

Embodiments relate to expandable tissue cavity markers and corresponding systems and deployment methods. In one embodiment, an expandable tissue cavity marker comprises a pouch and at least one radiopaque marker element. The pouch can transition between a compressed state, in which a profile or dimension of the tissue cavity marker is reduced such that the tissue cavity marker can be deployed through a minimally invasive surgical procedure incision, and an expanded state, in which a profile or dimension of the tissue cavity marker is increased such that the tissue cavity marker fills or defines a volume of a tissue cavity. In one embodiment, the pouch can be transformed between the compressed state and the expanded state by delivery of a fill material into the pouch. The pouch can comprise one or more functional materials in embodiments, including materials that provide an anti-infection, hemostasis, anti-migration, medicinal, or other function to the tissue cavity marker.

TECHNICAL FIELD

This disclosure relates generally to tissue markers and more particularly to expandable tissue cavity markers and corresponding systems and deployment methods.

BACKGROUND

Treatment of breast and other cancers often involves a biopsy, lumpectomy, or tumor or tissue resection. Many of these procedures now can be performed using minimally invasive procedures, such as by forming a small incision through which a biopsy tool or device can be inserted and removed. Minimally invasive procedures can be more comfortable and provide quicker healing for patients than open surgical procedures, while at the same time being less complex to perform.

After a biopsy, lumpectomy or resection procedure to remove tissue, localized radiation therapy can be provided to treat tissue remaining proximate the procedure area (e.g., at the “margin” of the cavity created when the tissue was removed) and reduce the chance of local recurrence in cases in which the removed tissue is found to be abnormal or cancerous and some abnormal or cancerous cells may have been left behind. To provide an accurate and lasting target for radiation, or simply to mark a tissue or cavity site for monitoring or future reference even if radiation therapy is not needed, radiopaque markers can be placed at the tissue removal site. While radiopaque markers can be placed at the site immediately after the tissue is removed, conventional markers typically are small in size and therefore can migrate within the cavity created when the tissue was removed or later as new tissue grows and fills the cavity. Conventional radiopaque markers also cannot fully define or mark the walls of the cavity.

To address this, some markers are mounted on or coupled to a support structure device that more completely fills the cavity volume. These support structure devices are large, however, and cannot be delivered via the same incision used in the minimally invasive procedure to remove the tissue. Moreover, these devices can be uncomfortable for patients both as they are delivered (and removed, if they must be later) and when they are in place.

SUMMARY

Embodiments of expandable tissue cavity markers and corresponding systems and deployment methods are disclosed.

In an embodiment, a tissue cavity marker for delivery to a tissue cavity via a delivery path between a minimally invasive surgical incision and the tissue cavity, the tissue cavity marker comprising an expandable pouch comprising at least one functional material and having a compressed state for delivery of the tissue cavity marker to the tissue cavity and an expanded state for residence within the tissue cavity, wherein injection of a fill material into the expandable pouch causes the expandable pouch to transition from the compressed state to the expanded state, wherein the expandable pouch is configured to retain the fill material therein in the expanded state, and wherein a diameter of the expandable pouch in the expanded state is at least about 1.5 times larger and not more than about 3.5 times larger than a diameter of the delivery path; and at least one radiopaque marker.

In an embodiment, a tissue cavity marking system for delivering a tissue cavity marker to a tissue cavity via a delivery path between a minimally invasive surgical incision and the tissue cavity, the system comprising a deployment device comprising a control mechanism at a proximal end and a tissue cavity marker aperture at a distal end, the control mechanism operable in use to deploy a tissue cavity marker from the tissue cavity marker aperture; and at least one tissue cavity marker comprising an expandable pouch comprising at least one functional material and having a compressed state for temporary arrangement in the tissue cavity marker aperture and an expanded state for residence within the tissue cavity, wherein injection of a fill material into the expandable pouch causes the expandable pouch to transition from the compressed state to the expanded state within the tissue cavity, wherein the expandable pouch is configured to retain the fill material therein in the expanded state, and wherein a diameter of the expandable pouch in the expanded state is at least about 1.5 times larger and not more than about 3.5 times larger than a diameter of the distal end of the deployment device; and at least one radiopaque marker.

DETAILED DESCRIPTION OF THE DRAWINGS

Embodiments relate to expandable tissue cavity markers and corresponding systems and deployment methods. In one embodiment, an expandable tissue cavity marker comprises a pouch and at least one radiopaque marker element coupled with the pouch. The pouch can transition between a compressed state, in which a profile or dimension of the tissue cavity marker is reduced such that the tissue cavity marker can be deployed through a minimally invasive surgical procedure incision, and an expanded state, in which a profile or dimension of the tissue cavity marker is increased such that the tissue cavity marker fills or defines a volume of a tissue cavity. In one embodiment, the pouch can be transformed between the compressed state and the expanded state by delivery of a fill material into the pouch. The pouch can comprise one or more functional materials in embodiments, including materials that provide an anti-infection, hemostasis, anti-migration, medicinal, or other function to the tissue cavity marker.

In another embodiment, an expandable tissue cavity marker comprises a pouch, a scaffold structure arranged in or on the pouch, and at least one radiopaque marker element coupled with either the pouch or the scaffold structure. Both the pouch and the scaffold structure can transform between a compressed state, in which a profile or dimension of the tissue cavity marker is reduced such that the tissue cavity marker can be deployed through a minimally invasive surgical procedure incision, and an expanded state, in which a profile or dimension of the tissue cavity marker is increased such that the tissue cavity marker fills or defines a volume of a tissue cavity. In one embodiment, the pouch and the scaffold structure can be transformed between the compressed state and the expanded state by delivery of a fill material into the pouch. One or both of the pouch or the scaffold structure can comprise one or more functional materials in embodiments, including materials that provide an anti-infection, hemostasis, anti-migration, medicinal, or other function to the tissue cavity marker.

Embodiments also relate to expandable tissue cavity marker deployment devices and systems. In one embodiment, a deployment device comprises a catheter, syringe or other tool having a proximal (operator) end and a distal (patient) end. The proximal end comprises a control mechanism by which the deployment device can be operated during use. The distal end comprises an aperture into which an expandable tissue cavity marker in the compressed state can be loaded. The tissue cavity marker can comprise a pouch with or without a scaffold structure. The distal end can be inserted through a minimally invasive surgical incision to deliver the tissue cavity marker to a target site, such as a tissue cavity. At the target site, the control mechanism can be used to deploy and release the tissue cavity marker from the deployment device. As it is being deployed, or after it has been deployed, the tissue cavity marker can be transitioned to the expanded state, such as by using the deployment device to deliver a fill material to the pouch. In other embodiments, the fill material can be delivered to the pouch using a separate device or tool.

Throughout this disclosure, some like elements are referenced similarly in different figures, iterated by factors of 100 (e.g.,100inFIG. 1A and 200inFIG. 2Aeach refer to tissue cavity markers but different embodiments thereof). Additionally, the drawings are not necessarily to scale, and the relative shapes and sizes of various components in some embodiments may not be exactly as depicted.

Referring toFIGS. 1A, 1B and 1C, one embodiment of an expandable tissue cavity marker100is depicted. Tissue cavity marker100comprises an expandable pouch110and at least one radiopaque marker120coupled with pouch110. InFIG. 1A, tissue cavity marker100and pouch110are depicted in a compressed or non-expanded state. InFIG. 1B, tissue cavity marker100and pouch110are depicted in an expanded state, and inFIG. 1Ctissue cavity marker100is depicted in the expanded state and comprising a fill material130within pouch110.

In this disclosure, the expanded state of tissue cavity marker100(and pouch110) is the state or configuration of tissue cavity marker100when it is deployed and resident in a tissue cavity, while the compressed state of tissue cavity marker100(and pouch110) is a state that enables at least one dimension (e.g., a diameter, radius, width or volume) but sometimes two or all three dimensions of tissue cavity marker100to be temporarily reduced in order to enable or ease delivery and deployment of tissue cavity marker100in a tissue cavity via a minimally invasive surgical incision. For example, in one embodiment at least two dimensions of tissue cavity marker100in its expanded state are greater than a length of a minimally invasive surgical incision, but in its compressed state these dimensions are reduced such that tissue cavity marker100can be delivered via the minimally invasive surgical incision. Minimally invasive surgical incisions can be about 3 centimeters (cm) long or less, such as about 2 cm long or less, or about 1 cm long or less, or less than about 7 mm long, for example about 6 mm long in one example. A range of minimally invasive surgical incision lengths is between 5 mm and 1 cm in one example. In some embodiments, tissue cavity marker100can have a third, rest state, which is a state in which tissue cavity marker100is not actively compressed, e.g., for deployment, but also is not expanded.

Pouch110of tissue cavity marker100is generally of a size and three-dimensional shape with both sufficient flexibility (to be compressed for delivery and deployment, and then expanded once in place) and rigidity (to maintain, for some amount of time and aided by fill material130or other structures in some embodiments, an expanded state) to be used as a marker in a tissue cavity created by a biopsy, lumpectomy or other resection of tissue. In embodiments, pouch110is compatible with a minimally-invasive deployment device. For example, pouch110or tissue cavity marker100overall can have a diameter dcin its compressed state (seeFIG. 1A) of about 10 millimeters (mm) or less, such as about 8 mm or less, about 7.5 mm or less, about 7 mm or less, about 6.5 mm or less, about 6 mm or less, or about 5 mm or less, in various embodiments. After deployment and in its expanded state, pouch110or tissue cavity marker100overall can have a diameter of about 10 mm or more, such as about 12 mm or more, about 15 mm or more, about 20 mm or more, about 25 mm or more, or about 30 mm or more, in various embodiments. A range of diameters de(seeFIGS. 1B and 1C) of pouch110or tissue cavity marker100overall in the expanded state is about 10 mm to about 30 mm in one example.

In one particular example, a diameter dcof pouch110in its compressed state is less than about 7.5 mm such that it can be delivered by a device having a diameter of about 7.5 mm, and a diameter deof pouch110is about 20 mm. In this example, a diameter of the delivery path taken by the distal end of a deployment device between the incision and the tissue cavity is also about 7.5 mm or slightly larger, such as about 7.6 mm or 7.7 mm, though the path may partially collapse after the distal end of the deployment device is withdrawn and removed. In various embodiments, a diameter of the distal end of the deployment device is between about 6 mm and about 8 mm, such as between about 6.4 mm and about 7.6 mm, or about 6.5 mm in embodiment, or about 7.5 mm in another embodiment. The difference between diameter deof pouch110and the 7.5 mm diameter of the insertion portion of the deployment device (and therefore also the approximate diameter of the delivery path) can discourage or prevent migration of tissue cavity marker100along the track of the deployment device.

In various embodiments, the diameter deof pouch110is at least about 1.5 times, at least about 2 times, at least about 2.5 times, at least about 3 times, at least about or at least about 5 times the diameter of the insertion portion or distal end of the deployment device. Thus, the diameter deof pouch110can be about 1.5 times to about 5 times, or about 1.6 times to about 3 times, the diameter of the insertion portion or distal end of the deployment device. At the same time, the diameter deof pouch110is not more than about 10 times, or not more than about 8 times, or not more than about 7 times, or not more than about 6 times, or not more than about 5 times the diameter of the insertion portion of the deployment device. For example, in one embodiment the diameter deof pouch110is at least about 3 times but not more than about 5 times the diameter of the insertion portion of the deployment device.

In some embodiments, diameter dein an expanded but unfilled state (FIG. 1B) and diameter dein a filled state (FIG. 1C) may not be identical. For example, fill material130can cause the diameter to increase slightly if a sufficient amount of fill material130is added to pouch110and pouch110has at least some elasticity. In some situations, it can be advantageous to completely fill or slightly overfill pouch110with fill material130as the pressure provided by pouch110on the tissue margin around the tissue cavity can ease or prevent bleeding. This also can be achieved by selecting a size of pouch110with a diameter dethat is the same as or slightly larger than the diameter of the tissue cavity. In another example, underfilling of pouch110with fill material130can result in the diameter decreasing slightly if pouch110is not rigid.

Pouch110generally comprises a pouch, pocket, sac, membrane, bag or other structure with an exterior perimeter that defines an internal volume in which fill material130can be retained. Pouch110can comprise an uninterrupted, unitary body in some embodiments, while in other embodiments pouch can comprise one or more seams, fill apertures, or other features. Pouch110can comprise a cloth or other woven material, a mesh material, a non-woven material, a fiber material, or another material or combination of these or other materials. The material can be stiffened, coated, permeated, or otherwise treated by another material or process in various embodiments. In various embodiments, pouch110can be porous or non-porous.

In some embodiments, pouch110comprises a functional or multifunctional material. For example, pouch110can comprise a material with one or more of anti-infection, anti-migration or hemostasis properties. Materials with anti-infection properties are those capable of acting against infection, such as by preventing the occurrence of an infectious agent, inhibiting the spread of an infectious agent, or harming or killing the infectious agent. One example of a material with anti-infection properties is TYRX available from MEDTRONIC. Materials with anti-migration properties are those that inhibit movement such that the structure remains in an intended location or orientation. One example of a material with anti-migration properties is PROGRIP available from MEDTRONIC. Materials with hemostasis properties are those that inhibit the flow of blood. One example of a material with hemostasis properties is VERISET available from MEDTRONIC. In some embodiments, pouch110also comprises a material that bioabsorbable or resorbable.

Pouch110can comprise these or other functional or multi-functional materials with the aforementioned or other properties in various embodiments110. For example, in some embodiments pouch can comprise a medicament or drug to treat a tissue surrounding the cavity in which tissue cavity marker100is deployed. Pouch110itself can comprise a functional or multifunctional material in its entirety, or select portions of pouch110can comprise a functional or multifunctional material, or a functional or multifunctional material can be applied to at least a portion of pouch110, or some other arrangement or technique for incorporation a functional or multifunctional material into or on pouch110can be used.

In some embodiments, pouch110or a portion or feature thereof (e.g., scaffold structure240discussed in more detail below) comprises a shape-memory alloy material, such as Nitinol. Shape-memory alloys are not bioabsorbable but may have application in some procedures or situations in which bioabsorbability is not desired or required.

In some embodiments, pouch110can comprise features or structures in addition to, or in or on, the pouch itself. For example, pouch110can comprise a fill aperture (not shown), such as a one-way valve, by which fill material130can be added to pouch110. In one embodiment, the fill aperture also comprises a deployment aperture via which tissue cavity marker100is removably coupled with a device to facilitate delivery and deployment to a tissue cavity. In another embodiment, pouch110can comprise a self-healing material or portion such that pouch110can be pierced by a device delivering fill material130and after removal of the device the piercing closes and fill material130is retained within pouch110. In yet another embodiment, a clip, suture, or other closure device can be used to close a fill aperture or otherwise seal pouch100after fill material130is injected therein. In still other embodiments, pouch110can comprise a porous material, with fill material130selected such that its properties prevent it from leaking or otherwise escaping the confines of pouch110. Materials and features of various embodiments of pouch110and fill material130are discussed below.

Pouch110of tissue cavity marker100can comprise a variety of different three-dimensional shapes in an expanded state in various embodiments, such as the generally spherical configuration shown inFIGS. 1B and 1C. In other embodiments, pouch110can be ovular, ovoid, spheroid, ellipsoid, cylindrical, cuboid, conical, prismatic, pyramid, or some other three-dimensional shape, including a combination of two or more of these shapes. A particular tissue cavity size, configuration, patient anatomy or type (e.g., human adult, human pediatric, veterinary), deployment device or situation, or other characteristic may benefit from a custom shape, which can be created in some embodiments. For example, tissue cavity marker100is sized and shaped for residence in a tissue cavity and can be sized and shaped so as to just fit within a particular cavity or to be slightly compressed when installed in and restrained by the tissue surrounding the cavity. In at least this sense, tissue cavity marker100can physically interact with at least a portion of a margin of the cavity in which it is deployed.

Tissue cavity marker100also comprises at least one radiopaque marker120in embodiments. Radiopaque materials are those that are opaque to and therefore visible on X-ray or other radiation images. Examples of radiopaque materials include metals (e.g., titanium, nonferromagnetic stainless steel) as well as some plastics and polymers known to those of ordinary skill in the art. Including radiopaque markers120on tissue cavity marker100makes it possible to locate markers120(and thereby the cavity in which tissue cavity marker100is resident) on radiation images after tissue cavity marker100is deployed in the cavity, including after pouch110is resorbed in embodiments in which pouch110is bioabsorbable. The longevity of radiopaque markers120can be helpful for follow-up treatments (e.g., targeted radiation therapy) and ongoing monitoring of the cavity and tissue margins of the cavity, while coupling radiopaque markers120with pouch110can prevent migration until new tissue has grown into a tissue cavity.

The number, size and relative arrangement of markers120can vary from those depicted inFIGS. 1A, 1B and 1C. As depicted, tissue cavity marker100comprises four markers120arranged in or on a surface of pouch110. In other embodiments, more or fewer markers120can be used, and the placements and relative arrangement of markers120can vary. Additionally, some markers120may be smaller, larger, or differently shaped than other markers120. The compressed and expanded states of tissue cavity marker100can be considered when arranging a plurality of markers120thereon. For example, two markers120can be staggered such that when tissue cavity marker100is in the compressed state ofFIG. 1Aadjacent markers120do not align in ways that interfere with one another, and a profile of tissue cavity marker100can still be sufficiently reduced to be loaded into a deployment device and delivered by a minimally invasive surgical incision.

Structurally, markers120can comprise clips that are coupled to pouch110in one embodiment. This coupling can be accomplished in a variety of ways, such as by folding, wrapping, crimping, embedding, adhering, applying, or otherwise attaching a portion of marker material to a portion of pouch110. In other embodiments, markers120can be coupled with pouch110by being at least partially embedded or arranged therein (e.g., within pouch110). In still other embodiments, pouch110can be formed in or on one or more markers120, such as by being woven into or injection-molded through a marker120that comprises a ring, tube or other structure that is hollow or comprises an aperture through which a portion of pouch110can pass. In further embodiments, one or both of pouch110and markers120can be three-dimensionally printed, together or separately.

In embodiments, tissue cavity marker100transitions from a compressed (or rest) state to an expanded state by insertion of a fill material130. In other words, delivery of fill material130into pouch110causes pouch110to expand. In one embodiment, a volume of fill material130is provided to completely fill pouch110, causing tissue cavity marker100to fully occupy the cavity. In other embodiments, the volume of fill material130to use in any particular situation can be selected by a medical professional, including by adjustment during filling (e.g., continuing to inject fill material130until a desired state is reached, or having the ability to remove injected fill material130). Fill material130can be delivered into pouch110in a variety of ways, such as by injection by the same deployment device that delivers and deploys tissue cavity marker100or by a separate device, for example a syringe.

Fill material130can comprise a gas, liquid, gel, powder, particulate, or other material or combination of materials (e.g., a particulate suspended in a liquid). Example materials include air, water, saline, a bioabsorbable material (e.g., DURASEAL, a bioabsorbable hydrogel available from MEDTRONIC), a biocompatible hydrogel, collagen (e.g., PERMACOL, a collagen paste available from MEDTRONIC), or a combination of these or other suitable materials. In one embodiment, fill material130, like pouch110discussed above, can comprise a functional or multifunctional material, such as one that provides anti-infection or hemostasis functions. In still other embodiments, fill material130can comprise a material that changes state, such as from a liquid when injected to a gel after some amount of time passes, or from a dehydrated gel to a hydrated gel upon injection of saline. The state transition can be effected by combination or compounding with another material, a temperature change, passage of time, being acted on by an external factor (e.g., application of radiation), or some other factor.

Referring toFIGS. 2A, 2B and 2C, a tissue cavity marker200comprises a pouch210, at least one marker220, and a scaffold structure240. The materials, properties, behaviors, and other characteristics of tissue cavity marker200, pouch210and markers220are similar to or the same as those discussed above with respect to tissue cavity marker100, pouch110and markers120, respectively, unless otherwise discussed explicitly herein.

Scaffold structure240can provide additional structural support to tissue cavity marker100, particularly in an expanded state. As depicted in the embodiment ofFIG. 2A, scaffold structure240can be present within pouch210in a compressed state. In other words, scaffold structure240can be arranged within pouch210prior to tissue cavity marker100being delivered to and deployed with a tissue cavity. In another embodiment, tissue cavity marker100can be delivered without scaffold structure240, then scaffold structure240can be provided later, such as before, with or after fill material230. In yet another embodiment, scaffold structure240can be delivered and deployed to a tissue cavity first, and then pouch210can be delivered and deployed into or around scaffold structure240, followed by fill material230. In a further embodiment, pouch210and scaffold structure240are integrally formed with one another. In any embodiment, scaffold structure240, like pouch210, also has compressed and expanded states to facilitate delivery and deployment via a minimally invasive surgical incision as discussed herein.

Scaffold structure240can comprise a stent-type structure, a spring or coil structure, a helical structure, a shape-memory material structure, a sponge-type material structure, a dehydrated gel material structure, or some other material or structure. For example, scaffold structure240can comprise one of the shape-memory or other materials discussed herein with respect pouch110. In embodiment in which scaffold structure240comprises a stent or spring structure, the stent or spring structure can comprise compression spring-type structures that are compressed in the compressed state of pouch210and become uncompressed in the expanded state of pouch210such that they provide internal structural support to pouch210in the expanded state. In still other embodiments, and departing from the embodiment depicted inFIGS. 2A, 2B and 2C, scaffold structure240can be integrated with or comprise the same material as that of radiopaque markers120or220.

InFIGS. 2A, 2B and 2C, scaffold structure240comprises a plurality of angular members, which can be coupled with another at hinge or flex points. This is but one example embodiment of scaffold structure240. In other embodiments, scaffold structure240can comprise more or fewer members, curved rather than or in addition to angular members, a spring or helical structure, or some other configuration that can be compressed for deployment and delivery and expand with a tissue cavity to provide support to pouch210. For example, in one embodiment scaffold structure240can comprise a unitary element, such as a helical body or spring. In yet another embodiment, scaffold structure240can be integrated with or comprise part of fill material230.

Referring toFIGS. 3A, 3B and 3C, and returning to the example embodiment of tissue cavity marker100ofFIGS. 1A, 1B and 1C, a deployment device300is depicted. Deployment device300comprises a proximal control end310and a distal delivery end320. Here and throughout, “proximal” is used with respect to an operator/physician end (310) of deployment device300, and “distal” is used with respect to a patient or delivery end (320) of deployment device300.

Deployment device300can comprise a catheter, syringe or other device into which a tissue cavity marker (e.g., tissue cavity marker100) can be loaded in its compressed state, delivered to a cavity site via a minimally invasive surgical incision, deployed within the cavity, and transitioned from the compressed state to the expanded state, such as by injection of filler material130. In some embodiments, the transition from compressed to expanded state of tissue cavity marker100can be accomplished using at least one additional tool or device.

Proximal control end310of deployment device300comprises a control system312(depicted in simplified form but appreciate by those of skill in the art) via which deployment device300can be controlled. In particular, control system312allows an operator of deployment device300to manipulate deployment device300to insert distal delivery end320through an incision, guide distal delivery end320to a delivery site (such as a tissue cavity), and control deployment of tissue cavity marker100from distal delivery end320to the delivery site. Additionally, in the embodiment ofFIG. 3A, control system312further enables an operator to facilitate delivery of one or more fill materials130(discussed in more detail below). Control system312can comprise one or more of a plunger (depicted inFIG. 3A), guidewire, mechanical actuator, robotic or computer-assisted control mechanism, or some other control mechanism that can be manipulated in order to control deployment device300and effect delivery and deployment of tissue cavity marker100and injection of one or more fill materials130.

InFIG. 3A, deployment device300and control system312are configured to deliver fill material130that comprises a two-part compound130aand130bthat is mixed to form fill material130. Compound130ais arranged in chamber314, and compound130bis arranged in chamber316. In other embodiments, deployment device300and control system312can accommodate other multi-part compounds (e.g., three-part compound) or be configured for a single-part fill material130. In yet another embodiment, deployment device300and control system312can be configured to deliver multi-part fill materials in which the multiple parts are delivered sequentially rather than mixed as inFIG. 3A. In still other embodiments, as discussed above, fill material130can be delivered using a separate deployment device.

Distal delivery end320comprises a distal end aperture322into which compressed tissue cavity marker100can be loaded. In some embodiments, distal end aperture322can comprise or be part of a cannula, trocar, catheter or other hollow device forming part or all of distal delivery end320or deployment device300. Though many different configurations and types of devices can be used in various embodiments, they will be generally referred to herein, inclusively, as deployment device300and distal delivery end320. Distal delivery end320can be rigid or flexible, and straight, curved or angled, in various embodiments. In some particular embodiments, a first portion of distal delivery end320can be rigid, and a second portion of distal delivery end320can be flexible. Similarly, a first portion of distal delivery end320can be straight, and a second portion of distal delivery end320can be curved. At least a portion of distal delivery end320being rigid can be advantageous in some embodiments to assist an operator in manipulating deployment device300to maneuver tissue cavity marker100into place in a tissue cavity, though some operators may prefer a degree of flexibility.

In the embodiment ofFIG. 3A, distal delivery end320comprises at least two lumens: an outer lumen324comprising distal end aperture322and an inner lumen326for delivery of fill material130. In such an embodiment, control system312can facilitate independent operation of outer lumen324and inner lumen322, as discussed in more detail below. In another embodiment, inner lumen326can comprise an array of lumens for delivering multiple compounds or components. InFIG. 3A, outer lumen324has a larger diameter than inner lumen326, and inner lumen326is arranged within outer lumen324such that the two lumens are coaxial. In other embodiments, outer lumen324and inner lumen326can instead be adjacent one another or have some other relative arrangement.

InFIG. 3A, tissue cavity marker100(in its compressed state) is loaded into distal end aperture322, and fill material compounds130aand130bare loaded into chambers314and316, respectively. One tissue cavity marker100can be loaded into distal end aperture322, or multiple tissue cavity markers100can be loaded into distal end aperture322for sequential delivery, such as in a case in which multiple tissue cavities of a single patient are to be marked. In some embodiments, tissue cavity marker100can be preloaded into distal end aperture322, and compounds130aand130bcan be preloaded into chambers314and316, respectively. In such an embodiment, deployment device300can be provided in sterile packaging and need only be removed from the packaging by a physician or other medical professional in order to deliver and deploy tissue cavity marker100. In other embodiments, tissue cavity marker100can be provided in separate sterile packaging or in some other configuration separate from but relative to deployment device300. For example, tissue cavity marker100can be provided preloaded in its compressed state in distal delivery end320, with distal delivery end320provided in sterile packaging separate from proximal control portion310of deployment device300, which may be sterilizable and reusable in some embodiments. Prior to use, distal delivery end320can be removed from its packaging, coupled with proximal control portion310, and used to deliver and deploy tissue cavity marker100at a desired site. Similarly, compounds130aand130bcan be provided separately from deployment device300, with a desired amount of selected compounds130aand130bobtained and loaded into chambers130aand130bprior to use.

Still other ways of providing tissue cavity marker100, fill material130, deployment device300or portions thereof can be implemented in other embodiments. For example, it may be helpful to provide, separate from deployment device300, a variety of tissue cavity markers (100,200, etc.) and fill materials130from which a physician or other medical professional can select an appropriate one for any particular cavity, patient or procedure. In general, however, it can be convenient for tissue cavity marker100(in its compressed state) and fill material130to be preloaded in deployment device300to avoid a physician having to transition tissue cavity marker100from its rest state to its compressed state in order to load tissue cavity marker100into deployment device300. Nevertheless, there may be situations in which this is necessary or desired (e.g., according to physician preference).

Referring toFIG. 3B, deployment device300is depicted in use, with distal delivery end320inserted via a minimally invasive incision301in a patient's skin to an internal tissue cavity303, such as one created by a breast tissue biopsy or lumpectomy. In some embodiments, tissue cavity marker100in its compressed state is deployed in cavity303from distal delivery end320. For example, the tip of distal delivery end320and outer lumen324can be advanced to a proximal edge of cavity303, and tissue cavity marker100can be deployed from distal end aperture322by continuing to advance inner lumen326within outer lumen324using control system312as outer lumen324is maintained at the proximal edge of cavity303to deliver tissue cavity marker100into cavity303. In another embodiment, inner lumen326begins partially within tissue cavity marker100, the tip of distal delivery end320and outer lumen324can be advanced to a distal edge of cavity303, and tissue cavity marker100can be deployed from distal end aperture322by maintaining positioning of inner lumen326proximate the distal edge of cavity303while retracting outer lumen324using control system312, thereby delivering tissue cavity marker100into cavity303. In such an embodiment, fill material130can be injected into tissue cavity marker100during delivery and deployment, or afterward.

In some embodiments, image-guided surgical techniques can be used to view distal delivery end320as it is directed to cavity303and ensure tissue cavity marker100is placed within cavity303prior to or after deployment of tissue cavity marker100from deployment device300. In these embodiments, deployment device300can comprise a colorant, radiopaque or radiographic marker or filler, or other additive in or coating on distal delivery end320to aid in visualization or navigation.

Referring toFIG. 3C, tissue cavity marker100is transitioned to its expanded state within cavity303. In the embodiment ofFIG. 3C, this is accomplished by injecting fill material130into cavity tissue cavity marker100via inner lumen326(seeFIG. 3A) in distal delivery end320. As previously mentioned, this can be done using deployment device300(as tissue cavity marker100is being deployed within cavity303, or after tissue cavity marker100is deployed within cavity303) or by using a separate device (e.g., a syringe or separate fill material delivery device) after tissue cavity marker100is deployed within cavity303and deployment device300is retracted and removed.

In embodiments using tissue cavity marker200comprising scaffold structure240, the delivery and filling/expansion processes can be modified. For example, in one embodiment in which scaffold structure240is arranged in or otherwise coupled with pouch210, injecting fill material230into pouch210can cause scaffold structure240to expand along with pouch210. In another embodiment, scaffold structure240can be inserted into pouch210before or with fill material230, such as by deployment device300. In such an embodiment, deployment device300can comprise one or more additional inner lumens (not depicted) to deliver and deploy scaffold structure240, or scaffold structure240can be delivered via inner lumen326with fill material230, or scaffold structure240can be arranged sequentially after pouch210in distal end aperture322for delivery into pouch210after pouch210is already delivered to cavity303. In some embodiments, one or both of pouch110,210or scaffold structure240can be removably or temporarily coupled with inner lumen326to aid delivery and deployment to tissue cavity303. In any embodiment, either or both of fill material130,230or scaffold structure240can be delivered by deployment device300or some other, separate device.

Upon transition to its expanded state, tissue cavity marker100will remain in cavity303, and distal delivery end320can be retracted and removed. Because tissue cavity marker100generally will be left in cavity303indefinitely, incision301can be closed. As previously mentioned, tissue cavity marker100, and thereby cavity303, can be located on X-ray or other images via radiopaque markers120,220(seeFIGS. 1A, 1B, 1C, 2A, 2B and 2C) and will not migrate from cavity303because tissue cavity marker100holds them in place. Over time, new tissue will grow into cavity303and around tissue cavity marker100, and tissue cavity marker100(including both pouch110,210and scaffold structure240) will resorb, leaving only radiopaque markers120,220behind in the tissue now filling former cavity303.

While the examples discussed herein include tissue cavity marker100loaded in its compressed state into distal end aperture322of distal delivery end320of deployment device300, in other embodiments tissue cavity marker100can be loaded into distal end aperture322in its rest state or a partially expanded state.

Referring toFIG. 4, a method400of providing a tissue cavity marker, such as tissue cavity marker100or tissue cavity marker200, is depicted. At410, a tissue cavity marker is formed, such as comprising a pouch and optionally a scaffold structure. Forming the tissue cavity marker can include selecting an expanded shape of the tissue cavity marker, and cutting, molding, extruding, three-dimensionally printing, or otherwise manipulating a material to enable the desired complex, three-dimensional expanded shape. Forming the tissue cavity marker also can include one or more of forming at least one radiopaque marker, coupling at least one radiopaque maker to the pouch or the scaffold structure, forming the scaffold structure, or inserting the scaffold structure into the pouch or otherwise coupling the scaffold structure with the pouch, among other tasks. At420, a fill material can be selected. Selecting a fill material can include one or more of forming a fill material or assembling a plurality of compounds to be mixed to form the fill material. At430, one or both of the tissue cavity marker and the fill material can be loaded into a deployment device. This can include loading multiple compounds of the fill material into distinct chambers of the deployment device. The tissue cavity marker can be loaded into the deployment device in a rest state, a compressed state, or some other suitable state. At440, the loaded deployment device or an individual tissue cavity marker can be sealed in sterile packaging. In various embodiments, the order of activities depicted inFIG. 4can be changed, additional activities can be inserted, and depicted activities can be omitted.

Embodiments of the tissue cavity markers discussed herein provide advantages with respect to conventional tissue markers. For example, the ability of tissue cavity marker to be transitioned from a compressed or rest state to an expanded state enables the tissue cavity marker to be delivered via an incision with a length or other dimension that is smaller than a diameter or other dimension of the tissue cavity marker in its expanded state. The shape, dimensions and other characteristics of the tissue cavity maker in various embodiments also can be selected to provide a snug or custom fit of the tissue cavity marker within a cavity, thereby providing a secure support structure for the radiopaque marker(s) coupled to the tissue cavity marker and inhibiting the radiopaque markers from migrating within the cavity. Moreover, embodiments comprising a scaffold structure can provide additional support within the cavity and for radiopaque markers. The configuration of the tissue cavity marker and its ability to expand three-dimensionally within the cavity also provides for a plurality of radiopaque markers to be used to more completely define the margins of the cavity. Once new tissue has grown into the cavity and around the radiopque markers, the markers are less likely to migrate, such that the tissue cavity marker can be formed from a bioabsorbable material and need not be removed by another surgical procedure. This can increase patient comfort and recovery, reduce expense, and eliminate procedures (as well as the likelihood for complications) by eliminating the need for a second procedure to remove the tissue cavity marker. Additionally, the ability to customize the shape of the tissue cavity marker, whether or not a scaffold structure is used, and the type of fill material means it can be used in a variety of different places and procedures, including but not limited to breast tissue biopsies and lumpectomies as well as other tissue biopsy sites. Also, tissue cavity makers comprising functional materials (e.g., for any or all of the pouch, scaffold structure, or fill material) can provide additional benefits related to anti-infection, hemostasis or anti-migration of the tissue cavity marker or its components within a tissue cavity.