Patent ID: 12207805

DETAILED DESCRIPTION

The applicant has developed a collection device, assembly and procedure for more efficiently collecting tissue from bodily cavities. The collection device can be utilized for collecting various types of matter from cavities within the body. For purposes of this description, the collection device will be described as it would be used for collecting bone marrow from bone. When used for collecting bone marrow, the bone marrow can be collected for biopsy purposes, for use as a medium for bony regeneration, or for harvesting stem cells to be processed and used for the subsequent treatment of congenital defects, diseases or other conditions.

The collection device features a flexible cannulated shaft that allows for safe and efficient collection of bone marrow from a single entry point into the bone. The preferred flexible shaft is comprised of rigid components, including rigid interlocking segments that collectively form a flexible section. The rigid segments allow the shaft to be advanced though bone marrow without the need for a stylet or other type of structural reinforcement in or around the shaft. The flexible section allows the shaft to yield and bend as it advances through marrow, so as to follow a path of least resistance. Thus, after penetrating through the outer cortex, the flexible shaft can bend and advance along the inner aspect of the bone where higher concentrations of stem cells are found.

The flexibility of the shaft can also prevent the leading end of the shaft from penetrating through a bone wall opposite an entry point, because the flexible section causes the leading end to bend in response to contact with the bone wall. This provides a safe alternative to rigid needles, particularly when used in long bones or other areas in which the cavities are relatively narrow or confined.

Moreover, the flexible shaft can include a distal shaving tip with bone shaving features not present on conventional needles. The shaving features aid in cutting and displacing bone from the outer cortex during initial penetration into the bone. The shaving features can also allow the flexible shaft to cleanly remove a core of bone marrow material when advanced into an area containing a high concentration of stem cells. The core of material is cut cleanly from the surrounding material as the distal shaving tip moves through the material, yielding a core with a high concentration of stem cells preserved inside. By allowing a core of bone marrow to be removed, the stem cells are not diluted or mixed with blood and other matter. This avoids the need to employ subsequent processing such as centrifugation in order to separate the stem cells from other material.

Although the flexible shaft provides the benefit of removing a core of bone marrow, the flexible shaft also allows removal of stem cells by aspiration. This versatility allows the flexible shaft to be a dual purpose or “2-in-1” device that can alternate between being a coring device and an aspiration device, depending on conditions where the marrow is being collected. For example, the flexible shaft can be advanced through a non-linear trajectory in bone to cleanly remove a core of bone marrow from the bone. Once the core of bone marrow is retrieved from the flexible shaft, the flexible shaft can be reinserted into the bone through the same entry point, and advanced through the same trajectory to the location previously occupied by the core. The area previously occupied by the core is typically replaced by fluids containing stem cells, blood and other components. At this stage, the flexible shaft can be attached to a source of negative pressure, such as a syringe, to remove the stem cell-containing fluid by aspiration.

Referring now toFIGS.1and2, a collection instrument100for collecting tissue from a body cavity will be described in accordance with one embodiment of the invention. Collection instrument100features a hollow tubular body in the form of a hollow shaft110. Shaft110can be formed of any suitable medical grade material approved for surgical instrumentation, including but not limited to stainless steel. Shaft110includes a proximal end portion111that terminates at a proximal end112inside a handle portion160. For illustration purposes, the section of proximal end portion111and proximal end112inside handle portion160are shown in dashed line. Shaft110also includes a distal end portion113that terminates at a distal end114. Shaft110also includes a middle section116extending between proximal end portion111and distal end portion113. Middle section116includes a first end116acontiguous with and next to proximal end portion111, and a second end116bcontiguous with and next to distal end portion113. Shaft110features a tubular wall118extending between proximal end112and distal end114. Tubular wall118defines an outer wall surface118aand an inner wall surface118b, the latter having a small area visible through the open distal end114in the Figures. In addition, tubular wall118defines and surrounds a passage119that is circular in cross section. Passage119extends from proximal end112of shaft110to distal end114of the shaft.

Middle section116of shaft110includes an articulating section120that allows distal end portion113and a portion of the middle section to articulate or bend relative to proximal end portion111. Articulating sections in accordance with the invention can feature a variety of constructs that allow shaft110to articulate or bend. In one preferred embodiment, the articulating section includes a plurality of interlocking segments or elements, such as interlocking sections of the type and arrangement described in U.S. Pat. No. 8,366,559 entitled “Cannulated Flexible Drive Shaft”, the content of which is incorporated by reference herein in its entirety and for all purposes. For example, the articulating section can incorporate a FlexMetric® brand flexible surgical shaft marketed by Lenkbar, LLC of Naples, Fla., USA.

Articulating section120includes a first interlocking section130and a second interlocking section140. First interlocking section130has at least one pin132and at least one socket134. Likewise, second interlocking section140has at least one pin142and at least one socket144. Each pin is substantially triangular or trapezoidal shaped, and each socket is substantially triangular or trapezoidal shaped, having the same general shape as the corresponding pin. Pin132on first interlocking section130has a circumferential width that increases uniformly (i.e. at a constant rate) from outer wall surface118ato inner wall surface118b, so that the pin becomes gradually wider as it extends radially inwardly toward a longitudinal axis L of shaft110. Pin142on second interlocking section140has a circumferential width that decreases uniformly (i.e. at a constant rate) from outer wall surface118ato inner wall surface118b, so that the pin becomes gradually narrower as it extends radially inwardly toward longitudinal axis L of shaft110. The first and second interlocking sections130and140are cut at opposing angles to create at least one inward angled surface and at least one outward angled surface, the inward angled surface being adjacent to the outward angled surface.

Hollow shafts in accordance with the invention can be cannulated, with passages defined in various configurations. For example, passage119terminates at proximal end112to define a proximal opening122in shaft110. Passage119also terminates at distal end114to define a distal opening124in shaft110. Distal opening124is circular in cross section, as is the cross section of passage119, as noted earlier. In this arrangement, distal opening124is designed to receive a solid or semi-solid core of bone marrow into passage119as shaft110is advanced through a bone cavity. Inner wall surface118bforms a smooth, continuous and uninterrupted annular surface around passage119that slidingly receives a core. The smooth surface of inner wall surface118bminimizes frictional forces and shear stresses so that the core is removed cleanly and in a preserved condition.

Distal end portion113also includes a core drill150that can shave bone and cut smoothly through bone marrow as shaft110is manually driven through a bone cavity. Core drill150has an outer wall152which coincides with and is coextensive with outer wall surface118aof shaft. Thus, the outer diameter of core drill150is equal to the outer diameter of shaft110. Core drill150is divided into four cutting sections154, with each cutting section separated from adjacent cutting sections by recessed areas or flutes156. Flutes156extend in a longitudinal direction parallel to longitudinal axis L. Each cutting section154terminates with a cutting edge155at distal end114. In the example ofFIG.2, each flute156extends from the respective cutting edge155towards the second end116bof the middle section116and terminates at a respective flute end162. Each flute156is defined between a first (trailing) flute face156aand a second (leading) flute face156b, with the first flute face156aextending directly from the cutting edge155, and the second flute face156bbeing rotated around the longitudinal axis L relative to the first flute face156a. Each flute face166a,156bextends parallel to the longitudinal axis L. The suction port158is separate from the distal opening124and located adjacent to the flute156and between the cutting edge155and the flute end162. The illustrated suction port158extends through the second flute face156b. Each cutting edge155is connected to the second flute face156bof the adjacent flute156by a first connecting face155a, and a second connecting face155b, with the second connecting face155bbeing angled greater than the first connecting face155arelative to the longitudinal axis L.

As noted previously, shaft110is a versatile instrument that can remove bone marrow material by both coring and by aspiration. As such, shaft110functions in some instances as an auger-type tool that removes solid material in a preserved state from the body, and in other instances acts as a needle-type tool to remove liquid or fluid material by aspiration. With regard to aspiration, shafts in accordance with the invention can have one or more dedicated suction ports designed to aspirate fluid material from a bone cavity. For example, distal end portion113includes an elongated suction port158that extends through tubular wall118inside one of the flutes156. Suction port158and distal opening124act as suction inlets to remove material during aspiration.

Distal end portion113is shown with only one suction port158through wall118. Other embodiments in accordance with the invention can feature two, three or more suction ports through the tubular wall. The suction ports can all be located on the same cutting portion, or on more than one of the cutting portions. Therefore, it is contemplated that a shaft in accordance with the invention can feature a suction port on each cutting portion, with each suction port having an identical shape, relative position and relative orientation on its respective cutting portion as suction port158. Suction port158has the shape of a long narrow slot. The narrow width (i.e. the short dimension shown inFIG.2) of suction port158, combined with the relatively long length to width ratio, promotes the entry of liquid material into shaft110during aspiration, while substantially preventing large fragments of solid material, such as coagulated material or bone fragments, from entering the shaft.

Tissue collection instruments in accordance with the invention can have a variety of handle configurations to be gripped by a physician. In preferred embodiments, a handle portion is provided at the proximal end of the tissue collection instrument. The preferred handle portion is ergonomically configured to permit the physician to comfortably grip the instrument and manually apply different types of force to the shaft via the handle. These forces can include pushing and pulling forces to advance and withdraw the shaft, respectively, as well as twisting forces to rotate the shaft. Certain combinations of pushing force and twisting force can also induce bending of shaft110at the articulation section120during advancement of the shaft through the bone cavity.

Collection instrument100includes a T-shaped handle portion160that is attached to proximal end112of shaft110. Handle portion160includes a hex-shaped insert170and a winged portion180connected over the insert. Insert170has a proximal end172that provides a hub174for attaching other instruments to collection instrument100. Insert170also includes a distal end176that connects handle portion160to shaft110. Handle portions in accordance with the invention can be connected to shafts using any suitable connection, such as a pinned connection, a molded connection, or other alternative. In the present embodiment, distal end176of insert170is molded over proximal end112of shaft110, and winged portion180is press fitted over insert170. Winged portion180has two lateral extensions181. When handle portion160is attached to shaft110, lateral extensions181are arranged symmetrically with respect to longitudinal axis L.

Winged portion180includes a proximal end182and a distal end184. Proximal end182defines a generally flat planar surface183on each lateral extension181. In addition, distal end184defines a concave curvature or indent185on each lateral extension181. The indents185are designed to allow the physician to wrap his or her fingers around winged portion180, while resting his or her palm against planar surfaces183in a gripping position. In this gripping position, the physician can comfortably apply pushing force, pulling force, and twisting to shaft110. The physician can also sense or detect conditions around shaft110by tactile feel when collection instrument100is navigated in a patient. For example, when distal end114of shaft110contacts an obstruction, the physician can immediately sense resistance to further advancement in the direction of the obstruction. This resistance force can be sensed, for example, when collection instrument100advances no further, or advances more slowly. The resistance force is felt by the physician as planar surface183bears against the physician's palm with increased force. The physician can also sense when shaft110bends or yields in response to contact with an obstruction by the change in resistance force felt through winged portion180.

Collection devices in accordance with the invention can also include one or more features that assist the physician with visually monitoring the depth of insertion of the shaft inside the body. For example, shaft110includes a plurality of indicia190that are provided along outer wall surface118a. Indicia190can be produced by any suitable process, including but not limited to laser cutting, laser marking, etching, or other means. Various types of indicia can be provided in accordance with the invention. For example, indicia190include a first indicia in the form of incrementally spaced hash marks or lines192. Lines192extend circumferentially around outer wall surface118a. Indicia190also include a second indicia in the form of numberings194. Each numbering194is located adjacent to one of the lines192and corresponds to that line. The value of each numbering194represents a depth of insertion in centimeters. Each numbering194is an integer that represents the distance between its respective line192and distal end114of shaft110. When shaft110is advanced into an incision, and a line192aligns with the patient's skin surface, the numbering194corresponding to that line at the skin surface indicates the depth to which distal end114is advanced into the body.

Shafts in accordance with the invention can feature articulating sections that span a small fraction of the shaft's overall length, or a large fraction of the shaft's overall length, so as to provide a desired degree of bending, i.e. a desired “pivot cone”. For example, the longitudinal length of articulating section120is one-quarter or 25% of the total length of shaft110. Therefore, 25% of the shaft length is comprised of interlocking segments that allow distal end114to bend and pivot with respect to proximal end112. The remaining three-quarters or 75% of the total length of shaft110is a solid unitary section117that remains fixed in its orientation. Therefore, proximal end portion111and a majority of middle portion116are fixed in orientation, providing structural reinforcement that allows the shaft to be advanced through bone and tissue and maintain trajectory without buckling.

The length of the flexible section versus the length of the solid unitary section can of course be different in other embodiments. For example, a larger percentage of the length can be devoted to the articulating section to allow for a greater degree of bending and pivot motion. Alternatively, a smaller percentage of the length can be devoted to the articulating section to allow for a smaller degree of bending and pivot motion. As such, the length of the articulating section can be any percentage of the total length of the shaft, including but not limited to 5%, 10%, 15%, 20%, 25%, 30%, 35%, 40%, 45%, 50%, 55%, 60%, 65%, 70%, 75%, or 80% of the total length of the shaft. Percentages less than 5% or greater than 80% can also be used. Choosing a specific percentage allows the shaft's flexibility and pivot cone to be precisely controlled, unlike conventional flexible needles that are flexible along their entire lengths.

Collection instrument100can be used in combination with other instruments during different stages of a bone marrow harvesting procedure. Referring now toFIGS.3-5, a piercing instrument200is shown in accordance with another embodiment of the invention. Piercing instruments in accordance with the invention can include tools for puncturing or piercing tissue and bone, including but not limited to trocars. For example, piercing instrument200includes a sharp-tipped trocar portion201with a proximal end202, a distal end204, and a shaft206extending between the proximal end and the distal end. Piercing instrument200also includes a generally T-shaped handle portion260attached to proximal end202of trocar portion201.

The outer diameter of shaft206of trocar portion201is equal to or slightly smaller than the diameter of passage119in shaft110. That is, the outer diameter of shaft206is equal to or slightly smaller than the inner diameter of shaft110. In this configuration, passage119of shaft110is adapted to receive at least a portion of trocar portion201in a telescoping arrangement. In particular, shaft206of trocar portion201is adapted to be telescopically received into shaft110, so that collection instrument100and piercing instrument200are interconnected as an assembly. The longitudinal dimension or length of shaft206is slightly longer than the longitudinal dimension or length of shaft110. As such, a small leading portion207of shaft206projects beyond distal end114of shaft110in an exposed manner when trocar portion201is fully inserted into collection instrument100, as shown inFIG.5.

When trocar portions in accordance with the invention are fully inserted into tissue collection instruments, the handles of the two instruments preferably lock, nest or otherwise engage one another to limit movement of either instrument relative to the other instrument. For example, handle portion260is generally hollow and defines a recess268that conforms to the outer geometry of handle portion160. In this configuration, recess268receives winged portion180of handle portion160in a snug fit when trocar portion201is fully inserted into shaft110of collection instrument100, as shown inFIG.5. The snug fit secures the two handle portions160,260and their respective shafts together in a fixed assembly that only allows piercing instrument200to be withdrawn from collection instrument100, while preventing further advancement of the piercing instrument through shaft110, and preventing rotation of the piercing instrument relative to the collection instrument.

Collection instruments in accordance with the invention can also be connected to sources of negative pressure for purposes of aspirating material in liquid form. Referring now toFIGS.6-10, collection instrument100is shown with a source of negative pressure in the form of a suction syringe300. Suction syringe300includes a generally cylindrical collection chamber310and a plunger320that is axially displaceable inside the chamber to either draw fluid into the chamber under negative pressure, or to eject fluid from the chamber under positive pressure. Collection chamber310has a distal end314that attaches to hub174on collection instrument100. Syringes and collection devices in accordance with the invention can be attached to one another with any suitable attachment means. For example, distal end314of collection chamber310attaches to hub174in a fluid tight connection using a threaded Luer connection330. Luer connection330has a female threaded surface332that mates with a male threaded surface175on hub174.

When suction syringe300is attached to collection instrument100, plunger320can be pulled in a proximal direction to create negative pressure or suction inside shaft110. Liquid material that is present outside distal end portion113is drawn into shaft110in response to negative pressure created in passage119. Preferably, the forces that draw liquid into the passage are concentrated at the one or more suction ports158, but may also be present at distal opening124. The suction port(s)158and distal opening124are not the only openings in shaft110that can draw in liquids however. The interlocking sections of articulating section120are separated from one another by cutting lines that leave small gaps121through tubular wall118. Such gaps121could potentially draw in liquids. It is preferred that liquids only be drawn through the one or more suction ports and the distal opening. Therefore, preferred assemblies in accordance with the invention include one or more mechanisms to seal gaps121when negative pressure is applied inside shaft110.

Referring toFIG.9, instrument100is shown with an external mechanism in accordance with one embodiment for sealing gaps121between interlocking sections of articulating section120. The external mechanism is in the form of a flexible sheath or sleeve400placed over shaft110in a position covering gaps121. In this position, sleeve400prevents suction forces from drawing in liquid through the gaps. This, in turn, allows more negative pressure to develop inside shaft110to draw in more fluids through suction port(s)158. Sleeve400can be formed of any suitable medical material, including but not limited to medical grade plastic or silicone.

Referring toFIG.10, instrument100is shown with an internal mechanism in accordance with another embodiment for sealing gaps121between interlocking sections of articulating section120. The internal mechanism is in the form of a flexible cannula or suction tube330that attaches to syringe300generally, and more specifically, to the distal end314of collection chamber310. When plunger320is pulled to draw material into suction syringe300, negative pressure is created inside flexible cannula330and draws material into a distal end opening334defined at the distal end336of the cannula. The length of flexible cannula330can be such that the distal end336of the cannula terminates at a location adjacent to the suction port(s)158and distal to gaps121when suction syringe330is attached to collection device100. The sidewall331of flexible cannula330preferably engages inner wall surface118aof shaft110inside articulating section120to effectively seal off gaps121and prevent liquid from being drawn through the gaps.

Example—Bone Marrow Harvesting Procedure

Referring toFIG.11, one possible tissue collection procedure in accordance with the invention is shown in block diagram form. In this example, the procedure is a bone marrow harvesting procedure in which bone marrow and stems cells are collected from a patient's anterior or posterior ilium. The previously described collection instrument100, piercing instrument200, and suction syringe300will be referenced when describing individual steps. Other devices can also be used to carry out the method in accordance with the invention. In addition, the steps can be performed with or without additional steps known to physicians and medical professionals of ordinary skill in the art.

In step1000, the piercing instrument200is inserted through handle portion160of collection instrument100and into passage119of shaft110until the distal end of the piercing instrument is exposed through the distal end of the shaft. Prior to this step, the physician may apply an anti-coagulant to surfaces on tissue collection instrument100and piercing instrument200to prevent matter from clotting, particularly on the inside of the collection instrument.

A small incision is made in the patient's skin over the hip area, and the patient's tissue is bluntly dissected to expose the surface of the ilium. Tissue collection instrument100and piercing instrument200are then inserted into the incision and advanced to the exposed bone surface, at which time the sharp tip or point is placed on the desired entry point through the bone. The physician then presses their palm firmly against the winged portion180of handle portion160to apply axial pressure on the bone, while rotating the handle portion in a clockwise direction. Tissue collection instrument100and piercing instrument200are rotated in unison while axial pressure is maintained to manually drive piercing instrument200and shaft110through the cortical bone. The simultaneous application of axial pressure and rotation are continued until tissue collection instrument100and piercing instrument200completely penetrate through the cortical bone and enter the cavity in step2000. The moment of entry into the cavity can be sensed through tactile feel, as the amount of resistance to axial advancement drops the moment that the cortical bone is fully penetrated and no longer provides resistance. Entry into the bone cavity can also be confirmed using imaging. Once tissue collection instrument100and piercing instrument200enter the bone cavity, the piercing instrument is withdrawn from the tissue collection instrument in step3000, leaving the tissue collection instrument in place in the bone.

At this stage, tissue collection instrument100is used in a coring mode to collect a core of bone marrow in step4000. Handle portion160is simultaneously twisted and advanced to collect the bone marrow. Shaft110is no longer supported internally by piercing instrument200, and now has a moderate amount of freedom to bend. Nevertheless, the degree of flexibility of articulating section120is limited, so that shaft110is able to advance through bone marrow, albeit not in a straight path. The limited flexibility of articulating section120causes distal end portion113to yield under resistance as it is advances through marrow and/or contacts the inner aspect of the bone. This results in a bending movement that alters the direction of advancement as the collection instrument100is advanced, which prevents inadvertent penetration beyond the marrow space adding a safety advantage to the process

Tissue collection device100is simultaneously advanced and rotated through the bone like an auger until a core of bone marrow in the path of movement is collected inside passage119of shaft110. Shaft110is advanced into the ilium to a desired depth corresponding to the desired amount of marrow to be removed. For example, shaft110can be inserted to a depth of 3-4 cm. Once shaft110reaches the desired depth, further advancement is halted and the tissue collection device100is withdrawn from the patient in step5000. The core of bone marrow inside shaft110is then carefully removed from the shaft in step6000. The bone marrow can be removed from the shaft using a suitable instrument, such as piercing instrument200or other implement that can dislodge the core of bone marrow from passage119.

The removal of bone marrow from the bone can leave a void space in the bone cavity. Bone marrow in and around the void space can be agitated during insertion and/or removal of collection instrument from the bone cavity. This agitation can leave a fluid dispersion of stem cells and blood cells in the void space. At this stage, collection instrument100is operated in an aspiration mode to collect the stem cells dispersed in and around the void space. Collection instrument100is reinserted back through the same incision and entry point of the bone, and into the void space in step7000. In some instances, the physician may elect to insert piercing instrument200back into collection instrument100before reinserting the collection instrument into the incision. Piercing instrument200can provide an aid for finding the entry hole in the bone and inserting shaft110through the hole. Shaft110is advanced into the void space until distal end114of the shaft is located at an optimal position for drawing in stem cells.

To operate collection instrument100in the aspiration mode, the physician connects suction syringe300to collection instrument100by attaching distal end314of the suction syringe to hub174of the collection instrument. Negative pressure is then applied to the shaft to collect fluid and stem cells in the aspiration mode in step8000. To introduce negative pressure in the shaft, plunger320is pulled back, i.e. in a proximal direction away from collection instrument100. As negative pressure builds in shaft110, fluid and stem cells in the void space enter the shaft through the one or more suction ports158and travel up into collection chamber310of suction syringe300. The volume of fluid that is drawn into suction syringe can vary depending on various factors, including but not limited to the volume of the void space created during the prior coring step. The physician may elect to withdraw approximately 20 cubic centimeters of fluid, for example, to collect the fluid dispersion of stem cells. Once the desired volume of fluid is collected in collection chamber310, syringe300can be disconnected from collection instrument100, and the collected fluid with stem cells can be used immediately in a point-of-care application or transferred to storage for subsequent usage and/or processing. At this stage, the physician can withdraw the collection instrument100from the entry point and remove the instrument from the patient in step9000. Alternatively, the physician can reinsert collection instrument100back through the same incision and same entry point of the bone to collect additional material. For example, collection instrument100can remain connected with syringe300and guided into the same void space for further aspiration, or to a different location for aspiration. In such cases, steps7000and8000can be repeated. Alternatively, shaft110can be advanced into a new area in the bone to collect another core of bone marrow. In such a case, steps4000-6000can be repeated.

Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications, combinations, substitutions and/or rearrangements can be made with respect to the components and their features shown herein, with any such modification, combination, substitution and/or rearrangement being contemplated within the scope and range of equivalents of the claims and without departing from the invention.