SYSTEM, DEVICE, AND METHOD COMBINING BIOABSORBABLE FOAM WITH VACUUM TECHNOLOGY FOR NEOPLASTIC CYSTS

Abstract

A device for draining cysts includes a catheter system configured to deploy an absorbent material, including but not limited to a foam, into a cyst. The absorbent material advantageously absorbs fluid contained within the cyst, for example fluid that may remain following aspiration, reducing the potential for cyst recurrence. In various embodiments, the absorbent material may be bioabsorbable, radiolucent, echogenic, drug eluting, or a combination thereof. In some embodiments the device may further include or be coupled to a vacuum source which applies negative pressure to the cyst during foam delivery, thereby reduce the overall size and/or profile of the cyst.

Claims

1. A medical device comprising: an elongated body having a proximal end, a distal end, and a lumen extending from the proximal end to the distal end; a sheath disposed about the elongated body, wherein the sheath defines a chamber that is distal to the distal end of the elongated body, and wherein the chamber is in communication with the lumen; an absorbent material disposed within the chamber; and a release mechanism configured to force the absorbent material from the chamber, wherein the elongated body is configured to couple to a source of suction to apply suction through the lumen.

2. The medical device of claim 1, further comprising a handle coupled to the proximal end of the elongated body, wherein the handle comprises the source of suction.

3. The medical device of claim 2, wherein the handle comprises a bore in communication with the lumen, and wherein the source of suction comprises: a cylinder disposed within the bore; and a plunger disposed within the cylinder, wherein the plunger is configured to move proximally within the cylinder to apply suction through the lumen.

4. The medical device of claim 3, wherein the cylinder is adjustably disposed within the bore.

5. The medical device of claim 4, wherein the handle comprises a tab lock configured to control a height of the cylinder within the bore.

6. The medical device of claim 1, wherein the release mechanism comprises a pneumatic-assisted mechanism or a push mechanism.

7. The medical device of claim 6, wherein the push mechanism comprises a push rod extending through the lumen, and wherein an entirety of the absorbent material is distal to the push rod.

8. The medical device of claim 1, wherein the absorbent material comprises a foam, a gel, or a powder.

9. The medical device of claim 1, wherein the absorbent material comprises a radiolucent material, an echogenic material, a drug eluting material, a bioabsorbable material, a hemostatic material, or a combination thereof.

10. The medical device of claim 1, wherein a distal end of the sheath comprises one or more echogenic markers.

11. The medical device of claim 1, wherein the sheath and the elongated body are fixedly disposed relative to one another.

12. The medical device of claim 1, wherein the elongated body is configured for translation through a working channel of an endoscope or through a needle catheter.

13. A medical device comprising: an elongated body having a proximal end, a distal end, and a lumen extending from the proximal end to the distal end, a sheath disposed about the elongated body, wherein the sheath defines a chamber that is distal to the distal end of the elongated body, and wherein the chamber is in communication with the lumen; an absorbent material disposed within the chamber, wherein the absorbent material comprises a radiolucent material, an echogenic material, a drug eluting material, a bioabsorbable material, a hemostatic material, or a combination thereof; and a release mechanism configured to force the absorbent material from the chamber, wherein the elongated body is configured to couple to a source of suction to apply suction through the lumen.

14. The medical device of claim 13, further comprising a handle coupled to the elongated body, wherein the handle comprises: a bore in communication with the lumen; a cylinder disposed within the bore; and a plunger disposed within the cylinder, wherein the plunger is configured to move proximally within the cylinder to apply suction through the lumen.

15. The medical device of claim 13, wherein the elongated body is fixed to the sheath.

16. The medical device of claim 13, wherein the release mechanism comprises a pneumatic-assisted mechanism or a push mechanism.

17. The medical device of claim 16, wherein the push mechanism comprises a push rod extending through the lumen.

18. The medical device of claim 17, wherein the push rod is configured to move distally within the lumen to thereby force the absorbent material from the chamber.

19. A medical device comprising: an elongated body having a proximal end and a distal end, and a lumen extending from the proximal end to the distal end, a sheath disposed about the elongated body, wherein the sheath defines a chamber that is distal to and in communication with the lumen; an absorbent material disposed within the chamber; and a release mechanism configured to force the absorbent material from the chamber, wherein the release mechanism comprises a push mechanism or a pneumatic-assisted mechanism, and wherein the elongated body is configured to couple to a source of suction to apply suction through the lumen.

20. The medical device of claim 19, further comprising a handle, wherein the handle comprises the source of suction.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0012] The foregoing and other features of the present disclosure will become more fully apparent from the following description and appended claims, taken in conjunction with the accompanying drawings. Understanding that these drawings depict only several embodiments in accordance with the disclosure and are not to be considered limiting of its scope, the disclosure will be described with additional specificity and detail through use of the accompanying drawings. In the following detailed description, reference is made to the accompanying drawings, which form a part hereof. In the drawings, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, drawings, and claims are not meant to be limiting. Other embodiments may be utilized, and other changes may be made, without departing from the spirit or scope of the subject matter presented here. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the drawing, can be arranged, substituted, combined, and designed in a wide variety of different configurations, all of which are explicitly contemplated and make part of this disclosure.

[0013] FIGS. 1A and 1B illustrate one embodiment of a catheter system for deploying an expandable material;

[0014] FIG. 2 is a cross-sectional view of the catheter system of FIG. 1A;

[0015] FIG. 3 illustrates one embodiment of an ultrasound endoscope including a working channel though which the catheter system of FIG. 1A may be deployed as disclosed herein;

[0016] FIGS. 4A and 4B are cross sectional views illustrating one embodiment of a method of use in a catheter system such as that described with regard to FIG. 1A with an endoscope such as that of FIG. 2;

[0017] FIGS. 5A and 5B are cross-sectional views illustrating one embodiment of a method of use in a catheter system such as that described with regard to FIG. 1A with an endoscope such as that of FIG. 2;

[0018] FIGS. 6A-6D illustrate various views of a pancreas having a cyst treatment site, and are used to describe one embodiment of a method for deploying an expandable material using the catheter system of FIG. 1A to treat pancreatic cysts.

DETAILED DESCRIPTION

[0019] A device such as for managing cysts includes a catheter system shaped and configured to deploy an absorbent material, including but not limited to a foam, such as into a cyst. The absorbent material advantageously absorbs fluid (e.g., contained within a cyst), for example fluid that may remain following aspiration, reducing the potential for cyst recurrence. In various embodiments, the absorbent material may be bioabsorbable, radiolucent, echogenic, drug eluting, or a combination thereof.

[0020] In one embodiment, the device may further include or be coupled to a vacuum source which applies negative pressure to the cyst during and/or following foam delivery for drainage of the cyst, thereby reducing the overall size and/or profile of the cyst. Reducing the overall profile of the cyst may decrease the potential for cyst recurrence. In addition, reducing the overall profile may increase contact between the foam and the cyst sidewalls. In embodiments where the foam is coated with or otherwise incorporates drugs for localized therapy of the cyst, applying such vacuum pressure may increase treatment efficacy.

[0021] Various embodiments of such a device and method of cyst management will now be described. Reference in this specification to one embodiment, an embodiment, or in some embodiments means that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment of the invention. The appearances of the phrases one embodiment, an embodiment, or in some embodiments in various places in the specification are not necessarily all referring to the same embodiment, nor are separate or alternative embodiments necessarily mutually exclusive of other embodiments. Moreover, various features are described which may be exhibited by some embodiments and not by others. Similarly, various requirements are described which may be requirements for some embodiments but may not be requirements for other embodiments.

[0022] As used herein, the term distal refers to the end farthest away from the medical professional when introducing a medical device into a patient, while the term proximal refers to the end closest to the medical professional when introducing a medical device into a patient. A central axis means, with respect to an opening, a line that bisects a center point of the opening, extending longitudinally along the length of the opening when the opening comprises, for example, a tubular frame, a strut, or a bore.

[0023] FIG. 1A illustrates an example of a catheter system 100 including a handle 120 coupled to a catheter 140. The catheter 140, in one embodiment, comprises an elongate body 142 having a proximal end 141 releasably coupled to the handle 120 (for example, screwed on via knob 121) and a distal end 143. In one embodiment, the catheter may comprise a composite of layers of thermoplastic elastomer (TPE). Alternatively, nylon, polyurethanes, polyester, silicone, or other similar materials may be used to provide thin walls that may be extruded and layered over braided wires or coils for tensile and hoop strength, although the disclosed system is not limited to any particular material composition.

[0024] According to one embodiment, the catheter system is shaped and configured for management of pancreatic cysts, although the disclosure is not limited to use in the pancreas, and it is appreciated that the principles disclosed herein may be extended by one of skill in the art to cyst management throughout a body.

[0025] However, for embodiments wherein the catheter is shaped and configured for pancreatic cyst management, the length of the catheter 140 may be selected to enable the catheter to be transluminally navigated through the gastrointestinal tract to the pancreas. For example, the length of the catheter may range from at least about 1300 millimeters (mm) to about 1600 mm, such as between about 1300 mm and 1500 mm, or between about 1400 mm and 1600 mm or the like.

[0026] In one embodiment, the catheter 140 may comprise a sheath 145, disposed over the elongate body of the catheter 140. Similar to the elongate body, the sheath may be comprised of a thermoplastic elastomer, nylon, polyurethane, polyester, silicone, or other similar materials. In one embodiment, the sheath 145 may have a distal end 147 that extends past the distal end 143 of the elongate body 142, forming a chamber inside the distal end 147 of the sheath, wherein an absorbent material (such as foam) may be disposed for delivery to a cyst treatment site. In some embodiments, the distal end 147 may include one or more echogenic features 148, facilitating visualization of the distal end 147 during ultrasound.

[0027] Outer diameters of the elongate body 142 and/or sheath 145 are selected to enable the catheter to be advanced freely within a working channel of an endoscope. For example, in various embodiments the outer diameter of the elongate body 142 and/or sheath 145 may be at least about 1.5 mm and at most about 3.5 mm, such to fit and be extendible within an endoscope working channel (for example, a working channel having a 3.8 mm diameter) although the disclosure is not so limited.

[0028] In some embodiments, the sheath 145 and elongate body 142 may be translatably disposed relative to each other to enable release of the foam from the distal end 147 of the sheath 145. For example, in some embodiments, the sheath may be shaped and configured to be withdrawn proximally of the distal end 143 of the elongate body 142 of the catheter 140, or the elongate body 142 may be disposed to move proximally within the sheath 145.

[0029] In other embodiments, the sheath 145 and elongate body 142 may be fixedly disposed relative to each other, and the elongate body may comprise a suitable release mechanism (e.g., a push rod or the like) configured and positioned to release and/or expel and/or deploy (hereinafter release for the sake of convenience, without intent to limit) the sheathed foam from the distal end 147 of the sheath. Various embodiments of release mechanisms known to those of ordinary skill in the art as configured and positioned to release a material, such as the absorbable material from the distal end 147 of the sheath 145, at a desired site are considered within the scope of this disclosure. For example, any of the following release mechanisms may be used: a pneumatic-assisted mechanism to release foam/powder/gel; a mechanical structure (e.g., screw mechanism, plunger (push) mechanism etc.) to release foam/powder/gel; a release foam (by changing state of foam/powder/gel).

[0030] In one embodiment, a lumen 144 (FIG. 2) extends from the proximal end 141 of the elongate body 142 of the catheter 140 through the distal end 147 of the sheath. The lumen 144 provides a fluid flow pathway between the distal end 147 and a vacuum source associated with the handle 120, enabling proximal fluid suction through the catheter 140 during a cyst management process as disclosed below.

[0031] The handle 120 includes a housing 126 having a bore 250 (FIG. 2) extending therethrough. In one embodiment, a vacuum cylinder 125 is adjustably disposed within the proximal portion of the handle housing bore and a distal inlet port 123 is disposed at a distal end of the bore of the housing 126. In one embodiment, the housing 126 may include a tab lock 127 that may be used to control an adjustment height, and concomitantly an available vacuum force, provided by the vacuum cylinder 125. The distal inlet port 123 fluidly couples the lumen 144 of the catheter 140 to the bore 250 of the housing 126.

[0032] In one embodiment, a plunger rod 124 is translatably disposed within the vacuum cylinder 125, wherein the plunger rod 124 includes a distal plunger 224 that seals the proximal end of the bore against air inflow from outside the housing 126. As a result, proximal translation of the plunger rod 124 within the vacuum cylinder 125 creates a negative pressure within the bore of the housing 126, providing a proximal vacuum/suction force through the distal inlet 123 of the housing that draws fluid (e.g., gas and/or liquid) through the lumen 144 of the catheter 140.

[0033] In some embodiments, the handle 120 may also comprise release mechanisms configured and positioned to control delivery of the absorbent material to the cyst. For example, a dial 129 is shown disposed about the vacuum cylinder 125 of the handle 120. In one embodiment, rotation of the dial may control a release mechanism internal to the handle/catheter, that is configured and positioned to release the absorbent material from the distal end 147 of the catheter sheath 145. It is appreciated that any of a variety of release mechanisms may be used to manage the release of the absorbent material, and other release mechanisms, such as switches, knobs, buttons, thumbwheels, and the like are considered to be within the scope of this disclosure.

[0034] FIG. 1B illustrates one embodiment of an absorbent material 160 that may be disposed within the chamber at the distal end 147 of the sheath 145 and used as disclosed herein. In one embodiment, the absorbent material 160 may comprise a foam or gel or powder or similar material having the ability to absorb and retain biological fluid from the cyst, including but not limited to blood, mucus, and other bodily fluids. The foam may be an open cell foam for promoting drainage. According to one aspect, it is appreciated that deploying foam into the cyst to absorb excess fluids may reduce the recurrence of a cyst in that location. Examples of foams that may be suitable for such purpose include those having hemostatic properties, such as those formed from of porcine gelatin (e.g. the GelForm Sponge, manufactured by Pharmacia, of Kalamazoo, MI, or Surgifoam Sponge, manufactured by Ethicon, of Somerville, NJ), those comprised of bovine collagen (e.g. Ultrafoam, manufactured by Integra, of Plainsboro, NJ, Helistat, manufactured by Ethicon/J&J of Somerville, NJ), those composed of oxidized regenerated cellulose (ORC) (e.g., Surgicel Oxycel, manufactured by Ethicon/J&J) and the like or a combination thereof. Although the absorbent material 160 of FIG. 1B is shown having a generally cylinder shape, the present disclosure is not limited to a foam having any particular shape and/or size. It is appreciated that the amount of foam delivered to a cyst is dependent upon the size of the cyst cavity, and it is anticipated that the amount of foam disposed within the distal end 147 of the sheath 145 may store foam sufficient to treat multiple cysts. In various embodiments foam may be stored in a compressed form having a smaller volume than in a delivered form, which may be an expanded form, when the foam is outside of the sheath 145. In various embodiments, foam may take on substantially the same volume, shape, and/or form within the sheath 145 and when delivered outside of the sheath 145. By way of example, sufficient foam may be stored to treat more than one cyst, or a cyst requiring a foam larger than the foam provided. The foam may be provided in one or more cartridges and deployed depending on cyst size and/or the number of cysts. It will be appreciated that the foam need not be stored in the catheter. Instead (or in addition) the foam can be loaded through the handle 120 (such as by syringe) or through the distal end 143 of the catheter 140.

[0035] In some embodiments, the foam may comprise additional characteristics, in addition to properties of absorption. For example, in one embodiment, the foam may be a soft, resilient hemostatic bio foam capable of conforming to the cyst cavity and transitioning to a porous gel or other substance that may be absorbed by the body over time. In some embodiments, the foam may be coated by, or otherwise incorporate, therapeutic agents that accelerate healing of the cyst, and/or provide localized treatment, including cancer treatment, such as any therapeutic agents having properties to delay generation of fluid or to delay conversion of a cyst to malignant tissue, or any drug or drugs (known or to be developed) having healing properties. In some embodiments, the foam may be marked with or formed from substances increasing visibility of the treated cyst cavity during subsequent foam placement and subsequent imaging, for example, including radiolucent or echogenic markers or the like.

[0036] FIG. 2 is a cross-sectional view of the catheter system 100, showing a distal portion of catheter 140, and the handle 120. In FIG. 2, the foam 160 is visible within the distal end 147 of the catheter 140, disposed within a chamber 230 extending between the distal end 143 of the elongate body 142 of the catheter 140 and the distal end 147 of the sheath 145. A push rod 240 is positioned with a distal end 241 thereof adjacent to the chamber 230, and extends axially within the lumen 220 of the elongate body 142, from adjacent the chamber 230, through the distal inlet 123 of the handle housing 126 and into the housing 126 to a proximal end 242 of the push rod 240 positioned adjacent the release mechanism (e.g., dial) 129. Distal advancement of the push rod 240 by actuation of release mechanism 129 expels the foam 160 through the distal end 147 of the sheath 145.

[0037] An example of a vacuum source in the form of a plunger rod and plunger is illustrated in FIG. 2. A vacuum cylinder 125 is shown disposed within the bore 250 of the housing 126 and a plunger rod 124 is shown axially disposed within the vacuum cylinder 125. A plunger 224, disposed on the distal end of the plunger rod 124, may be formed of rubber or other material that enables the plunger rod 124 to move axially within the vacuum cylinder 125 without allowing external airflow into the bore 250. In various embodiments, a lumen (e.g., lumen 144 of FIG. 2) may be in fluid communication with a vacuum source (e.g., at a proximal end of the system 100).

[0038] According to one aspect, the catheter system 100 may be used as part of an Endoscopic Ultrasound (EUS) procedure for pancreatic cyst management. FIG. 3 illustrates one embodiment of an ultrasound endoscope 300 including a handle 310 and a steerable catheter 320 having an ultrasound transducer 330 disposed at its distal end. Various working channels may be disposed within the catheter 320, and instruments may access the working channels using one or more of the ports 340 disposed within the handle. Dials 315 of the handle 310 may be used to navigate a distal end 325 of the catheter 320 to a treatment site, e.g., to a cyst. FIG. 3 illustrates an aspiration needle 350, that has been disposed through a working channel of the endoscope 300 and deployed to aspirate fluid from a cyst.

[0039] FIGS. 4A and 4B are cross-sectional illustrations of a distal end of the endoscope 300, during a procedure, for example during cyst management. In FIG. 4A, an aspiration needle system 360, including a distal aspiration needle 350, has been forwarded distally through the working channel 322 of the catheter 320 of the endoscope. The needle 350 extends distally adjacent to the ultrasound transducer 330, enabling visualization of the aspiration procedure.

[0040] Following aspiration, the aspiration needle system 360 may be withdrawn from the working channel 322 while the endoscope is kept in position, and, as shown in FIG. 4B, the catheter 140 of the catheter system 100 may be advanced through the working channel 322 of the steerable catheter 320 to the aspirated cyst. Visualization of the distal end 147 of the catheter 140 is facilitated using the echogenic markers 148, which may be visualized using the ultrasound transducer 330.

[0041] FIGS. 5A and 5B are cross-sectional illustrations of a distal end of the endoscope 300, for example during another embodiment of a procedure such as cyst management. As in FIG. 4A, in FIG. 5A an aspiration needle system 360, including a distal aspiration needle 350 has been forwarded down the working channel 322 of the catheter 320 of the endoscope 300. The needle 350 extends distally adjacent to the ultrasound transducer 330, enabling visualization of the aspiration procedure. In FIG. 5A, the needle lumen 365, defining the aspiration path, is visible.

[0042] In FIG. 5B, following aspiration, the aspiration needle system 360 remains in place in the working channel 322, and the catheter 140 of the catheter system 100 may be advanced through the needle lumen 365 of the needle system 360 to the aspirated cyst. Accordingly, the catheter system may be advanced towards a cyst, and visualized, using a variety of available paths within the ultrasound endoscope.

[0043] FIGS. 6A-6D illustrate an example of a process for cyst management utilizing the catheter system 100 described above.

[0044] In FIG. 6A, the endoscope 300 may be advanced to a target position proximate a cyst 610 in the pancreas 600, for example along a gastrointestinal tract. Visualization of the environment and targeting of the cyst may be facilitated using the ultrasound transducer 330. An aspiration needle 350 may be advanced from the working channel of the endoscope 300 into the cyst 610 to drain cyst fluid.

[0045] As shown in FIG. 6B, following draining of cyst fluid, in one embodiment the needle is withdrawn and the distal end 147 of the catheter 140 may be advanced through the endoscope 300 towards the cyst 610.

[0046] As shown in FIG. 6C, following advancement of the distal end 147 of the catheter 140 to the cyst 610, the foam 160 may be released into the cyst 610. In one embodiment, prior to, during and/or after release of the foam 160 into the cyst 610, a proximal vacuum force draws the walls of the cyst and/or the foam towards the distal end 147 of the catheter 140, reducing the size of the cyst.

[0047] Following administration of the foam, in FIG. 6D, the endoscope may be removed from the gastrointestinal tract, and/or positioned to treat a different cyst. The cyst 610 remains, in reduced form with added foam 160, which continues to absorb cyst fluid over time, reducing cyst recurrence.

[0048] It should be noted that although the catheter system and method of use has been described as part of a transluminal procedure, other methods of access, including laparoscopic, percutaneous, and/or using endoscopic retrograde cholangiopancreatography may similarly benefit from the concepts disclosed herein.

[0049] Accordingly, catheter system and method of use thereof has been shown and described. Various modifications to the implementations described in this disclosure will be readily apparent to those skilled in the art, and the generic principles defined herein can be applied to other implementations without departing from the spirit or scope of this disclosure. Thus, the disclosure is not intended to be limited to the implementations shown herein but is to be accorded the widest scope consistent with the claims, the principles and the novel features disclosed herein. The word example is used exclusively herein to mean serving as an example, instance, or illustration. Any implementation described herein as example is not necessarily to be construed as preferred or advantageous over other implementations, unless otherwise stated.

[0050] Certain features that are described in this specification in the context of separate implementations also can be implemented in combination in a single implementation. Conversely, various features that are described in the context of a single implementation also can be implemented in multiple implementations separately or in any suitable sub-combination. Moreover, although features can be described above as acting in certain combinations and even initially claimed as such, one or more features from a claimed combination can in some cases be excised from the combination, and the claimed combination can be directed to a sub-combination or variation of a sub-combination.

[0051] Similarly, while operations are depicted in the drawings in a particular order, this should not be understood as requiring that such operations be performed in the particular order shown or in sequential order, or that all illustrated operations be performed, to achieve desirable results. Additionally, other implementations are within the scope of the following claims. In some cases, the actions recited in the claims can be performed in a different order and still achieve desirable results.

[0052] It will be understood by those within the art that, in general, terms used herein are generally intended as open terms (e.g., the term including should be interpreted as including but not limited to, the term having should be interpreted as having at least, the term includes should be interpreted as includes but is not limited to, etc.). It will be further understood by those within the art that if a specific number of an introduced claim recitation is intended, such an intent will be explicitly recited in the claim, and in the absence of such recitation no such intent is present. For example, as an aid to understanding, the following appended claims may contain usage of the introductory phrases at least one and one or more to introduce claim recitations. However, the use of such phrases should not be construed to imply that the introduction of a claim recitation by the indefinite articles a or an limits any particular claim containing such introduced claim recitation to embodiments containing only one such recitation, even when the same claim includes the introductory phrases one or more or at least one and indefinite articles such as a or an (e.g., a and/or an should typically be interpreted to mean at least one or one or more); the same holds true for the use of definite articles used to introduce claim recitations. In addition, even if a specific number of an introduced claim recitation is explicitly recited, those skilled in the art will recognize that such recitation should typically be interpreted to mean at least the recited number (e.g., the bare recitation of two recitations, without other modifiers, typically means at least two recitations, or two or more recitations). Furthermore, in those instances where a convention analogous to at least one of A, B, and C, etc. is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., a system having at least one of A, B, and C would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). In those instances where a convention analogous to at least one of A, B, or C, etc. is used, in general such a construction is intended in the sense one having skill in the art would understand the convention (e.g., a system having at least one of A, B, or C would include but not be limited to systems that have A alone, B alone, C alone, A and B together, A and C together, B and C together, and/or A, B, and C together, etc.). It will be further understood by those within the art that virtually any disjunctive word and/or phrase presenting two or more alternative terms, whether in the description, claims, or drawings, should be understood to contemplate the possibilities of including one of the terms, either of the terms, or both terms. For example, the phrase A or B will be understood to include the possibilities of A or B or A and B.