FIELD

[0001] Surface features for device retention are disclosed herein, e.g., for retaining an access port within a patient during a surgical procedure.

BACKGROUND

[0002] Access systems can be used in orthopedic surgery or neurosurgery to enable surgeons to introduce devices and/or instruments into a surgical site of a patient. For example, in spinal surgery, an access system can be implanted in situ to allow dilators, scalpels, and/or bone anchors to be passed to the surgical site to the one or more vertebrae. A typical access system can be advanced into the patient until it reaches the surgical site and secured therein, after which instruments and devices can be passed therethrough. Implantation of the access system, while invasive, can provide a clear path of access to the surgical site while minimizing damage to surrounding tissue that can be caused by operating tools.

[0003] Existing access systems can have numerous shortcomings. Muscle tissue, e.g. spine muscle, is very strong and can be prone to resisting advancement of the access system therethrough. Muscle activity can also exert a force that can dislodge or even eject the access system back out of the patient, which can cause slippage of surgical instruments that would damage surrounding tissue and increase time spent in the operating room reinserting the system. Securing the access system to the patient by way of anchors or staples can be overly invasive and hinder frequent repositioning of the system that may be required during surgery. Such modifications can also make removal of the access system difficult and cause excessive tissue damage.

[0004] Accordingly, there is a continual need for systems and methods that can discourage ejection and retain access systems within surgical sites while minimizing damage to surrounding tissue. SUMMARY

[0005] Surface features for device retention are disclosed herein, e.g., for retaining an access port within a patient during a surgical procedure. The surface features can prevent ejection of the access port from a body of a patient. The surface features can be positioned along the access port and configured to glide along body tissues with minimal friction so as not to hinder travel of the access port in an insertion direction. After insertion of the access port, the surface features can engage with surrounding tissue to increase friction therebetween and to prevent ejection of the access port from the patient. Deployment of the surface features can occur due to friction with the surrounding tissue and/or via activation of the surface features to protrude from the access port. The surface features can include teeth, hooks, scales, fins, bristles, braids, and/or threads for engaging tissue. The surface features can be disengaged from the tissue to enable withdrawal of the access port without damaging the surrounding tissue.

[0006] In one aspect, a surgical device is provided that can include an access device. Further, the access device can include an inner sidewall, an outer sidewall, a proximal end, a distal end, and an opening extending between the proximal and distal ends to receive an instrument therethrough, and one or more structures can be coupled to the outer surface. Still further, the one or more structures can include a first surface and a second surface, such that the first surface contacts the tissue during advancement of the access device in an insertion direction into a body of a patient, and is configured to minimize friction between the first surface and tissue, and the second surface contacts the tissue during advancement of the access device in a direction opposite to the insertion direction to prevent proximal movement of the device out of the body, and is configured to increase friction between the second surface and tissue.

[0007] The devices and methods described herein can have a number of additional features and/or variations, all of which are within the scope of the present disclosure. In some embodiments, for example, the one or more structures can be coupled to the outer surface at a flexion point. Further, the one or more structures can be configured to flex about the flexion point with respect to the access device. Still further, flexion of the structures about the flexion point can alternate the structures between the first surface and the second surface for contacting tissue. [0008] In certain embodiments, the structures can flex due to friction with surrounding tissue. For example, in some embodiments, the structures can flex from approximately 20 degrees relative to the outer surface of the access port to approximately 180 degrees relative to the outer surface of the access device. In some embodiments, the surgical device can be entirely comprised of the access device having the one or more structures formed thereon. Further, in certain embodiments, the one or more structures on the outer surface can be positioned unidirectionally relative to one another. Still further, in some embodiments, the one or more structures can be formed on a sleeve that is coupled to the device. And in some embodiments, the surface structures can include a layer of biased fibers on the outer surface of the access device.

[0009] In certain embodiments, the one or more structures can project radially outward from the outer surface to prevent proximal movement of the device out of the body. Further, in some embodiments, the one or more structures can be arranged to point in a direction that is opposite of the insertion direction. The one or more structures, in certain embodiments, can further include any of teeth, fish scales, fins, flaps, skins, bristles, braids, hooks, and threads. And in certain

embodiments, the one or more structures can be made of any of rubber, polystyrene, nylon, yam, mohair, plastic, polyalkenes, polypropylene, polyethylene, fluorinated polyolefins,

polytetrafluoroethylene, PTFE, ePTFE, cPTFE, polyvinylidene fluoride, blends of

polyvinylidene fluoride and copolymers of vinylidene fluoride and hexafluoropropene, polyamides, polyurethanes, polyisoprenes, polystyrenes, polysilicones, polycarbonates, polyetheretherketones (PEEK), polyarylether ketones (PAEK), polymethacrylic acid esters, polyacrylic acid esters, aromatic polyesters, polyimides, or polyamides.

[0010] In some embodiments, the second surface can include one or more edges configured to penetrate tissue to become disposed therein. And in some embodiments, the access device cannot be housed in another device during insertion.

[001 1] In another aspect, a surgical method is provided that can include inserting an access device into a body of a patient. Further, the access device can include an inner surface, an outer surface, a proximal end, a distal end, an opening extending between the proximal and distal ends to receive an instrument therethrough, and one or more structures formed on an outer surface thereof. The method can further include translating the access device through the body in a first direction, the one or more structures traveling relative to the body; and deploying one or more structures from the outer surface of the access device to couple the structures to the body to increase friction between the structures and the body.

As with the above-described aspect, a number of additional features and/or variations can be included, all of which are within the scope of the present disclosure. In some embodiments, for example, a surface of the structures can contact tissue in the body of the patient during translation of the access device in the insertion direction. In some embodiments, the structures cannot be housed in another device during insertion. Further, in certain embodiments, deploying the structures can further include flexing of the structures relative to the outer surface. Still further, in certain embodiments, flexing of the structures can occur about a flexion point formed on the access device.

[0012] In certain embodiments, the surface structures can deploy due to friction with tissue. In some embodiments, deploying the structures can further include rotating the access device relative to its longitudinal axis in a first direction to deploy the structures into the tissue to prevent movement of the device relative to the body and rotating the access device relative to its longitudinal axis in a second, opposite direction to retract the structures to allow movement of the device relative to the body. And, in certain embodiments, the method can further include decoupling the structures from the body and withdrawing the access device from the body of the patient, the access device translating in a second, opposite direction to the insertion direction, the structures contacting tissue in the body of the patient during translation of the access device in the second direction.

[0013] Any of the features or variations described above can be applied to any particular aspect or embodiment of the present disclosure in a number of different combinations. The absence of explicit recitation of any particular combination is due solely to the avoidance of repetition in this summary.

BRIEF DESCRIPTION OF THE DRAWINGS

[0014] The following detailed description is provided with the accompanying drawings, in which:

[0015] FIG. 1 is a perspective view of an exemplary access port;

[0016] FIG. 2 is a perspective view of an access port having surface features thereon; [0017] FIG. 3 is a perspective view of a sleeve that can be used with the access port of FIG. 1;

[0018] FIG. 4A is a perspective view of the sleeve of FIG. 3 coupled to the access port of FIG. i ;

[0019] FIG. 4B is a perspective view of the access port of FIG. 4A cut open while inserted into a patient;

[0020] FIG. 5 is a perspective view of an exemplary embodiment of surface features formed on the access port of FIG. 1 ;

[0021] FIG. 6 is a perspective view of another exemplary embodiment of surface features formed on the access port of FIG. 1 ;

[0022] FIG. 7 is a perspective view of another exemplary embodiment of surface features formed on the access port of FIG. 1 ;

[0023] FIG. 8 is a perspective view of another exemplary embodiment of surface features on the access port of FIG. 1;

[0024] FIG. 9A is perspective view of another exemplary embodiment of surface features on a sheet material;

[0025] FIG. 9B is a detail perspective view of the surface features of FIG. 9A;

[0026] FIG. 9C is a side perspective view of the surface features of FIG. 9A;

[0027] FIG. 10A is another exemplary embodiment of surface features formed on the access port of FIG. 1;

[0028] FIG. 10B is a detail perspective view of the surface features of FIG. 10A; and

[0029] FIG. IOC is a detail perspective view of the surface features of FIG. 10A, showing a main strand having bristles thereon. DETAILED DESCRIPTION

[0030] Surface features for device retention are disclosed herein, e.g., for retaining an access port within a patient during a surgical procedure. The surface features can prevent ejection of the access port from a body of a patient. The surface features can be positioned along the access port and configured to glide along body tissues with minimal friction so as not to hinder travel of the access port in an insertion direction. After insertion of the access port, the surface features can engage with surrounding tissue to increase friction therebetween and to prevent ejection of the access port from the patient. Deployment of the surface features can occur due to friction with the surrounding tissue and/or via activation of the surface features to protrude from the access port. The surface features can include teeth, hooks, scales, fins, bristles, braids, and/or threads for engaging tissue. The surface features can be disengaged from the tissue to enable withdrawal of the access port without damaging the surrounding tissue.

[0031] Certain exemplary embodiments will now be described to provide an overall

understanding of the principles of the structure, function, manufacture, and use of the devices and methods disclosed herein. One or more examples of these embodiments are illustrated in the accompanying drawings. Those skilled in the art will understand that the devices and methods specifically described herein and illustrated in the accompanying drawings are non-limiting exemplary embodiments. The features illustrated or described in connection with one exemplary embodiment may be combined with the features of other embodiments.

[0032] FIG. 1 illustrates an exemplary embodiment of an access port 100 that can be inserted or slid into a patient. For example, the access port 100 can be used to create an access path for objects, e.g., devices such as bone anchors, instruments and/or surgical material, e.g., sutures, to be introduced into a surgical site. The access port 100 can include a generally tubular or cylindrical-shaped body defined by a sidewall 102 having a central opening 104. The opening 104 can extend along an axis A1 from a proximal end lOOp of the access port 100 to a distal end of the access port lOOd. In some embodiments, the opening 104 can be shaped to correspond with a shape of an object or an instrument being inserted therethrough. It will be appreciated that the access port 100 can be a cannula, tube, retractor, bladed retractor, dilator, and/or another example of an access device known to one having ordinary skill in the art for creating an access path into a surgical site of a patient. As shown, the access port 100 can have a uniform diameter D, though, in some embodiments, the access port 100 can have two or more diameters.

[0033] The access port 100 disclosed herein can be made from a rigid or a flexible material. Some non-limiting examples of rigid materials can include stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and so forth. Some non-limiting examples of flexible materials can include rubber, any of a variety of flexible polymers, and so forth. The material can be chosen based on the surgical site, type of surgery, and/or the objects used during the procedure. Rigid materials can provide added support for objects introduced into the surgical site, while flexible materials can be more easily manipulated by a surgeon to increase an amount of space at the surgical site. It will be appreciated that flexible materials that are sufficiently deformable can allow the access port to be removed when intended, without damaging surrounding tissue. For example, in some embodiments an access port can be made from a flexible woven material that can allow the access port to dynamically change size based on whatever instrument, implant, etc. is being passed therethrough. Such a construction can minimize tissue damage by minimizing a size of the port passing through tissue during times when, e.g., no instrument (or a small instrument) is being passed therethrough. Such woven ports, however, can be particularly susceptible to backing out in response to muscle activity and, as a result, can benefit from inclusion of the surface features described herein.

[0034] The sidewall 102 of the illustrated access port 100 can be smooth to facilitate insertion of the access port with minimal friction. While minimizing damage to surrounding tissue, having a smooth sidewall 102 can make the access port 100 prone to unintended backing out of the patient. In some embodiments, surface structures can be added to the access port 100 to retain the access port within the surgical site and prevent ejection, as described further below.

[0035] FIG. 2 illustrates an exemplary embodiment of an access port 100 having surface features 110 that can be used to retain and/or anchor the access port 100. For example, the surface features 110 can prevent axial ejection of the port 100 from the surgical site. The surface features 110 can be formed on, or attached to, the sidewall 102 of the access port 104. The surface features 1 10 can protrude from the sidewall 102 to modify and/or alter the sidewall 102. [0036] In some embodiments, the surface features 1 10 can include a roughening of the sidewall 102 to modify the structure thereof. The surface features 1 10 can create a counter-friction when the sidewall 102 engages with tissue. More particularly, roughening the sidewall 102 increases friction between the sidewall 102 and the tissue to help minimize and/or prevent the risk of unintended ejection of the access port 102. The surface features 110 can be shaped such that any tearing of tissue is minimized during insertion and ejection of the access port 102. For example, the surface features 110 can have gliding properties in an insertion direction A so as to minimize friction in the insertion direction A and not hinder insertion, as described further below.

[0037] The surface features 1 10 can engage and/or become disposed in tissue at the surgical site to create counter-friction therebetween, thereby preventing ejection of the access port. The surface features 110 can be formed integrally with the access port 110, or can be separate components that are welded, threaded, glued, thermally or mechanically fixed, or otherwise associated with the access port. In some embodiments, the surface features 1 10 can be formed on a sleeve that can be coupled, threaded, glued, thermally or mechanically fixed, or otherwise associated with the access port, as further described below.

[0038] The surface features 1 10 can be arranged along the sidewall 102 extending from the proximal end 1 OOp to the distal end 1 OOd of the access port 100, as shown, though, in some embodiments, the surface features 110 can be located on one or more of the proximal portion lOOp, the distal portion lOOd, or an intermediate portion.

[0039] Varying a location of the surface features 110 on the access port 100 can affect a location at which the access port will be disposed. In some embodiments, a distal-most end of the access port 100, e.g., approximately 1-10 mm of the distal-most end, approximately 3-7mm of the distal-most end, or approximately 5mm of the distal-most end, can be free of surface structures. Allowing a sidewall 102 free of surface features to be introduced into the surgical site prior to the access port 100 have surface features 110 thereon can gradually dilate the surgical site to prepare the patient for introduction of the surface features therein.

[0040] In use, the access port 100 can be advanced distally in an insertion direction A into the surgical site. During insertion of the access port 100, the surface features 110 can travel along a surface of the tissues without becoming engaged therein. It will be appreciated that the surface features 110 can be oriented to minimize friction with the tissue when the access port is being advanced to allow the access port to be advanced to the desired location. Once inserted, the surface features 110 can engage surrounding tissue to prevent ejection of the access port 100. In some embodiments, the surface features 1 10 can deploy due to friction with the surrounding tissue, or can actively deploy to engage surrounding tissue, as described further below. After engaging tissue to be sufficiently secured at the desired location, devices, instruments, and other materials can be introduced into the body of the patient through the access port 100. At the conclusion of the surgical procedure, the surface features 110 can disengage from the tissues and the access port 100 can advanced in a direction opposite to the insertion direction A, e.g.

proximally, to remove the access port 100 from the surgical site. It will be appreciated that the surface features 110 can be sufficiently manipulated to disengage from the tissue to allow the port to be removed from the surgical site when intended without damaging surrounding tissues.

[0041] FIGS. 3-10 illustrate a number of variations on the surface features described above. Except as indicated or as will be readily appreciated by one having ordinary skill in the art having read the present disclosure, the structure and operation of these variations is substantially the same as that of the surface features described above and therefore a detailed description is omitted here for the sake of brevity.

[0042] FIG. 3 illustrates an exemplary embodiment of a sleeve 200 having surface features or teeth 210 attached thereto. The sleeve can include a generally tubular or cylindrical-shaped body defined by a sidewall 202 having a central opening 204. The opening 204 can extend along an axis A2 from a proximal end 200p of the sleeve to a distal end 200d of the sleeve 200, which can be parallel to the axis A1 that extends through the access port 100. In some embodiments, the opening 204 can be shaped to correspond with a shape of an object or an instrument being inserted therethrough. As shown, the sleeve can have a uniform diameter D 1 , though, in some embodiments, the sleeve 200 can have two or more diameters. In some embodiments, the diameter D1 of the sleeve 200 can be equal to the diameter D of the access port 100, though, in some embodiments, the diameter D1 of the sleeve 200 can be larger and/or smaller than the diameter D of the access port 100. [0043] One or more surface features 210 can extend from the sidewall 202 of the sleeve 210. As shown, the surface features 210 can resemble teeth that penetrate tissue to secure the access port thereto. The teeth can have one or more edges 212 for grasping surrounding tissue. As shown, the teeth can have a leading edge 214 and a trailing edge 216. The leading edge 214 can have a sharp surface that penetrates the tissue to retain the access port 100 at a given location. The trailing edge 216 can follow the leading edge 214 into the tissue to provide an additional point of engagement for the teeth with the tissue.

[0044] While teeth having two edges are shown, it will be appreciated that, in some

embodiments, teeth having one edge, or three or more edges can be used. Similarly, while the surface features have a generally triangular shape, as shown, the surface features 210 can be rectangular, square, pentagonal, hexagonal, and so forth. Surface features of different shapes can include a smaller or larger number of edges 214 that can engage tissue. The greater the number of edges 212 of each surface feature 210 that can engage with tissue, the more stable the retention of the access port 100 in the surgical site, which can reduce the chances that the access port 100 can be ejected unintentionally from the surgical site.

[0045] As shown, the surface features 210 can be arranged uniformly along a circumference of the sleeve 200, though it will be appreciated that alternate arrangements with random and/or non- uniform distribution of surface features 210 are possible. The size, number, and spacing of the surface features 210 can be selected based on the type of surgical procedure, the location of the surgical site, and a degree of securement desired to prevent ejection of the access port.

[0046] For example, as shown, the surface features 210 can be arranged in one or more rings R along a circumference of the sleeve 200. Arranging the surface features in rings can allow the surface features 210 to be distributed throughout the circumference of the sleeve 200, which can allow the sleeve to be inserted into the surgical site in any orientation. Each surface feature 210 can be equally spaced from each adjacent surface feature, as shown, though, in some

embodiments, equal spacing between adjacent surface features is not maintained. Equal spacing between surface features 210 can allow for maximum flexion of each surface feature 210 during insertion and ejection without interference from adjacent surface features, as described further below. [0047] The number of surface features 210 per ring R can vary based on a diameter D1 of the sleeve 200. Each ring R can include approximately five surface features thereon, approximately ten surface features thereon, approximately fifteen surface features thereon, and/or

approximately twenty or more surface features thereon. Likewise, the number of rings formed on the sleeve 200 can vary based on a length L of the sleeve 200. Each sleeve can include approximately two rings thereon, approximately five rings thereon, approximately ten rings thereon, and/or approximately fifteen or more rings thereon. It will be appreciated that a larger number of surface features 210 formed on the sleeve can increase a strength of the engagement between the surface features 210 and the tissue.

[0048] The surface features 210 can be manufactured such that no other component or device houses the surface features 210 during insertion. The surface features 210 can include gliding properties thereon so as not to hinder advancement of the access port through the surgical site. For example, the surface features 210 can include a top surface 230 that glides along a surface of the tissue during advancement of the access port in the insertion direction A. The top surface 230 can be manufactured from materials having a low coefficient of friction to facilitate insertion while preventing inadvertent engagement and/or damage to tissue during insertion. In some embodiments, the surface features 210 can be withdrawn into an interior of the access port 100 so as to prevent contact of the tissue during insertion of the access port.

[0049] The surface features 210 can flex and/or pivot relative the sidewall 202. Flexing of the surface features 210 can reduce and/or minimize friction with surrounding tissue. As shown, the surface features 210 can protrude from the sidewall 202 at an angle with respect to the sidewall 202. The angle of the surface feature 210 can be such that a force applied by tissues during insertion of the sleeve 200 in the insertion direction A can flex the surface features 210 towards the sidewall to decrease the angle of the surface feature 210 relative to the sidewall 202. The degree to which the surface features 210 can flex with respect to the sidewall 202 is discussed in further detailed with regards to the embodiments below, while still applying to the instant embodiment.

[0050] The surface features can be formed and/or manufactured from a soft, elastic and/or a flexible material, e.g., rubber, polystyrene, nylon, yam, mohair, plastic, that can bend and/or flex. In some embodiments, the surface features 210 can be formed from a material of the sleeve, e.g., by cutting a series of flaps into the sleeve and/or the access port, molded, extruded, or any other technique known in the art for manufacturing surface features. In some embodiments, one or more of fish scales, fins, flaps, skins, hairs, hooks, threads, and/or other examples of features known to one skilled in the art for engaging tissue can be used in lieu of, or in addition to, teeth to increase friction with surrounding tissue.

[0051] The surface features 210 can deploy from the access port 100 in a variety of ways. For example, the surface features 210 can be arranged to point in a given direction such that motion in an opposite direction activates the surface features 210, causing them to flex and engage surrounding tissues. As shown in FIG. 3, the surface features 210 can be arranged to point proximally, e.g., in a direction substantially opposite of the insertion direction A of the sleeve 200. A tip 218 of the surface features can point at an angle that is approximately 155 degrees with respect to the insertion direction A, approximately 165 degrees with respect to the insertion direction A, approximately 175 degrees with respect to the insertion direction A, and/or approximately 180 degrees with respect to the insertion direction A.

[0052] When the tip 218 points substantially opposite to the insertion direction A, during advancement in the insertion direction, the surrounding tissue imparts a force onto the surface features 210 that causes them to flex to lie against the sidewall 102. In this position, in some embodiments, the edges 212 of the surface features 210 do not engage the surrounding tissue. Rather, the surface features 210 are flexed such that the top surface contacts tissue to slide therealong. Once advancement is stopped, the force on the surface features 210 decreases, causing them to return to their initial position. During removal of the access port 100, friction between the surface features and the tissue can cause the surface features 210 to deploy to flex in a direction that is perpendicular to the insertion direction A to engage the tissue, which resists removal of the access port 100. In some embodiments, the surface features 210 can actively deploy by virtue of being made from a shape memory material and/or via mechanical actuation such as a deployment sleeve or another deployment means known to one skilled in the art.

[0053] The sleeve 200 can be coupled to a distal end lOOd of the access port 100, as shown in FIG. 4A, though, in some embodiments the sleeve 200 can be coupled to the proximal end lOOp of the access port 100, be formed integrally with the port 100, conform to an outer shape of the access port 100, or slide over the access port 100 to receive the access port therein. The access port 100 can be manufactured from the same material as the sleeve 200, though, in some embodiments, the access port 100 can be flexible while the sleeve 200 is more rigid. Use of a flexible access port 100 can allow for a greater degree of manipulation of the access port 100 during the procedure to provide a surgeon with more room to operate. In some embodiments, after being inserted into the patient, the access port 100 can be cut such that the access port lies flush with the skin, as shown in FIG. 4B. Cutting the access port in this manner can increase access to the surgical site when performing surgery.

[0054] FIG. 5 illustrates an alternate embodiment of surface features 210' that can be used with the access port 100 described above. As shown, the surface features 210' can be coupled and/or attached directly to the sidewall 102 of the access port 100. As discussed with regards to the embodiments above, a leading edge 214' and a trailing edge 216' of the surface features 210' can come to a pointed tip 218' at one of the edges 212' of the surface features 210' to penetrate tissue.

[0055] Flexion of the surface features 210' can vary based on a shape and orientation of the surface features 210' on the sidewall 202. For example, the surface features 210' can have one or more flexion points along the access port 100. Flexion points can determine a degree of flexion of a surface feature 210' with respect to the access port 100 and/or the direction in which each surface feature 210' can flex and/or pivot. As shown in FIG. 5, each surface feature 210' includes two flexion points 220', 222' at a location where the surface feature 210' meets the access port 100, the flexion points resembling a base of an oblique triangle. As mentioned above, while the surface features have a generally triangular shape, as shown, the surface features 210 can be rectangular, square, pentagonal, hexagonal, and so forth. The surface features 210' can include one, or three or more flexion points that connect the surface features 210' to the access port to allow flexion relative therewith.

[0056] The number of flexion points can determine a direction and/or plane about which the surface feature can pivot. For example, as shown in FIG. 5, the surface features 210' can pivot about flexion points 220', 222'. The surface features 210' can pivot about both flexion points from being substantially parallel to an insertion direction A of the access port 100 to being substantially perpendicular to the insertion direction A. Pivoting of the surface features 210' about both flexion points 220', 222' can occur during insertion and/or withdrawal of the access port 100 from the surgical site and during engagement and disengagement with surrounding tissue.

[0057] A distance between flexion points can also determine the degree of flexion of a surface feature relative to the sidewall 202. For example, increasing a distance between flexion points can increase stiffness of the surface features, thereby limiting the degree to which surface features can flex and/or bend. The surface features 210' can flex about flexion points 220', 222' approximately to 10 degrees relative to the sidewall of the access port, can flex approximately to 25 degrees relative to the sidewall of the access port, can flex approximately to 45 degrees relative to the sidewall of the access port, can flex approximately to 65 degrees relative to the sidewall of the access port, can flex approximately to 75 degrees relative to the sidewall of the access port, and/or can flex approximately to 90 degrees relative to the sidewall of the access port.

[0058] FIG. 6 illustrates an alternate embodiment of surface features that can be used with the access port described above. The surface features 210" can include a hooking feature 224 thereon to increase counter-friction and retention within the tissue to prevent backing out. As shown, the hooking feature 224 can be formed in a trailing edge 216", though it will be appreciated that, in some embodiments, the hooking feature 224 can be formed in a leading edge 214".

[0059] The surface features 210" can have one or more additional features for increasing the flexibility and/or decreasing the stiffness of the surface features. For example, as shown, the trailing edge 216" can include a hinge 226 formed therein. The hinge 226 can be cut-out from the surface feature 210" or formed as a notch in the surface feature. The hinge 226 decreases the stiffness of the surface feature 210", thereby allowing the surface feature to move across a larger degree of flexion.

[0060] The surface features 210" can include two flexion points 220”, 222". As discussed above, when a distance between flexion points is reduced, the degree of flexion of a surface feature relative to the sidewall 202 increases. For example, the surface features 210" can flex about flexion points 220", 222" approximately to 20 degrees relative to the sidewall of the access port, can flex approximately to 50 degrees relative to the sidewall of the access port, can flex approximately to 70 degrees relative to the sidewall of the access port, can flex approximately to 90 degrees relative to the sidewall of the access port, can flex approximately to 120 degrees relative to the sidewall of the access port, and/or can flex approximately to 145 degrees relative to the sidewall of the access port, which represents a larger degree of flexion than the embodiment of FIG. 5.

[0061] FIG. 7 illustrates an alternate embodiment of surface features that can be used with the access port described above. The surface features 210'" can be attached to the access port 100 via a flange 228. As shown, the surface features 210'" can pivot, bend, and/or flex relative to the access port about the flange 228 during insertion, retention, and/or withdrawal. The narrow distance between the contact points 220'", 222'" of the flange can allow the surface feature 210"' to flex approximately to 30 degrees relative to the sidewall of the access port, to flex

approximately to 70 degrees relative to the sidewall of the access port, to flex approximately to 90 degrees relative to the sidewall of the access port, to flex approximately to 120 degrees relative to the sidewall of the access port, to flex approximately to 145 degrees relative to the sidewall of the access port, to flex approximately to 165 degrees relative to the sidewall of the access port, and/or to flex approximately to 180 degrees relative to the sidewall of the access port which represents a larger degree of flexion than the embodiments of FIGS. 5 and 6.

[0062] The durability and/or stiffness of the material used to form the surface features can also impact flexion. The surface features 210', 210", 210"', as discussed with regards to FIGS. 5-7, as well as the remainder of the embodiments discussed herein, can be formed and/or

manufactured from a soft, elastic and/or a flexible material, e.g., rubber, polystyrene, nylon, yam, mohair, plastic, that can bend and/or flex. In some embodiments, the surface features 210', 210", 210'" can be formed from a material of the sleeve, e.g., by cutting a series of flaps into the sleeve and/or the access port, molded, extruded, or any other technique known in the art for manufacturing surface features. In some embodiments, one or more of fish scales, fins, flaps, skins, hairs, hooks, threads, and/or other examples of features known to one skilled in the art for engaging tissue can be used in lieu of, or in addition to, the surface features described herein to increase friction with surrounding tissue. [0063] FIG. 8 illustrates an alternate embodiment of surface features 310 that can be used with the access port 100 described above. As shown, the surface features can include a layer of biased structures 310 formed and/or attached to the sidewall 102 of the access port 100. The structures 310 can be attached by strips or sleeves onto the sidewall 102. In some embodiments, the structures 310 can be formed on a sleeve (not shown) that can be pulled over the access port 100.

[0064] Similar to the embodiments described above, the biased structures 310 can be arranged such they point unidirectionally. The biased structures 310 can then flex in a given direction to facilitate insertion of the access port 100 in the insertion direction A. In some embodiments, the structures can flex from approximately 0 degrees to approximately 180 degrees relative to the sidewall 102 of the access port. The structures 310 can include top surfaces 330 for engaging tissue. During advancement in the insertion direction A, the tissue can exert a force on the structures 310 to flex the structures such that the top surfaces 330 point away from the tissue to minimize friction during advancement. Movement in the opposite direction can bring the top surfaces 330 in contact with the tissue, causing the structures to adhere to tissues and create counter-friction to prevent backing out.

[0065] The structures can be formed and/or manufactured from a soft, elastic and/or a flexible material, e.g., rubber, polystyrene, nylon, yam, mohair, plastic, that can bend and/or flex. In some embodiments, the surface features 310 can be formed from a material of the sleeve, e.g., by cutting a series of flaps into the sleeve and/or access port, molded, extruded, or any other technique known in the art for manufacturing surface features. In some embodiments, one or more of fish scales, fins, flaps, skins, teeth, hooks, threads, and/or other examples of features known to one skilled in the art for grasping tissue can be used in lieu of, or in addition to, the structures described herein to increase friction with surrounding tissue.

[0066] FIGS. 9 A— 9C illustrate another exemplary embodiment of surface features or hooks that can be used with the access port described above. As shown, the hooks 410 can be printed on a sheet and/or film 432 for being attached to the sidewall 102 of the access port 100. The film 432 can have one or more surface features 410 that project radially outward from a surface thereof to engage with tissue. The film 432 can be fabricated using laser cutting machines and/or any other technique known to one skilled in the art, e.g., extrusion punched and/or laser cut having specifically defined shapes therein. As shown in FIG. 9B, the surface features are shaped like hooks, though it will be appreciated that the features can include one or more of fish scales, fins, flaps, skins, hairs, teeth, threads, and/or other examples of features known to one skilled in the art for grasping tissue can be used in lieu of, or in addition to, the hooks described herein to increase friction with surrounding tissue. In some embodiments, the surface features can be formed and/or manufactured from a soft, elastic and/or a flexible material that can bend and/or flex, e.g., rubber, polystyrene, nylon, yam, mohair, plastic, polyalkenes, polypropylene, polyethylene, fluorinated polyolefins, polytetrafluoroethylene, PTFE, ePTFE, cPTFE, polyvinylidene fluoride, blends of polyvinylidene fluoride and copolymers of vinylidene fluoride and hexafluoropropene, polyamides, polyurethanes, polyisoprenes, polystyrenes, polysilicones, polycarbonates, polyetheretherketones (PEEK), polyarylether ketones (PAEK), polymethacrylic acid esters, polyacrylic acid esters, aromatic polyesters, polyimides, and/or polyamides. In some embodiments, the surface features 410 can be formed from a material of the sleeve, e.g., by cutting a series of flaps into the sleeve and/or access port, molded, extruded, or any other technique known in the art for manufacturing surface features.

[0067] The hooks 410 can point unidirectionally to reduce and/or minimize friction during advancement of the sleeve 200 and/or the access port 100 in the insertion direction A. For example, as shown in FIGS. 9B-9C, the hooks 410 can extend in a direction B that is substantially perpendicular to the insertion direction A of the access port 100 to engage tissue, though, in some embodiments, the hooks 410 can point proximally, e.g., in a direction opposite to the insertion direction A, as discussed above, or at an oblique angle with respect to the insertion direction A. Engaging tissue in a direction perpendicular to the insertion direction A can enhance retention of the access port 100 by increasing the counter-friction with the surrounding tissue. Once the hooks 410 have engaged tissue, exertion of a proximal force onto the access port is less likely to disengage the hooks 410 from the tissue, which will prevent unwanted ejection of the access port.

[0068] The film 432 can be wrapped around the sidewall 102 and mechanically fixed thereto, though, in some embodiments, the film 432 can be welded, threaded, glued, thermally or mechanically fixed, or otherwise associated with the access port to engage with tissue. In some embodiments, the film 432 can be manufactured to form a helically-shaped hook pattern, though it will be appreciated that a variety of patterns can be imprinted on the film.

[0069] FIGS. 10 A- IOC illustrate another exemplary embodiment of surface features that can be used with the access port described above. As shown in FIG. 10A, the access port 100 can include a groove 106 in the sidewall 102 thereof. The groove 106 can be formed in a helical shape, as shown. The groove 106 can extend from the proximal end 1 OOp to the distal end 1 OOd of the access port 100, as shown, or it can extend through a single end of the port, as shown in FIG. 10B.

[0070] The groove 106 can include a main strand 108 therein. The main strand 108 can be seated in the groove 106 such that the main strand 108 does not protrude from the groove 106, though, in some embodiments, the main strand 108 can extend from the groove 106 or wrap around the sidewall 102 between adjacent portions of the groove. The main strand 106 can include a single, continuous piece of filament or yam that extends through the groove, or the main strand 108 can be composed of two or more strands that are glued, tied, wrapped, thermally or mechanically fixed, or otherwise associated with one another and/or the groove. The main strand 108 can extend through an entire length of the groove 106, as shown in FIG. 10B, in which the groove is located on a distal end of the access port, or through a portion of the groove. In some embodiments, the main strand 108 can be fixed to the groove 106 at its first end and at its second end, though, in some embodiments, the main strand 108 can be fixed to the groove 106 at more than two points or throughout its length.

[0071] The main strand 108 can include one or more surface features or bristles 510 that protmde therefrom. The bristles 510 can be hair-like projections that extend from the main strand 108. As shown in FIG. IOC, the bristles 510 can extend can point substantially unidirectionally from the main strand 108 to reduce and/or minimize friction during

advancement of the sleeve 200 and/or the access port 100 in the insertion direction A, though, in some embodiments, the bristles 510 can extend in multiple directions to engage tissue. The bristles 510 can be formed and/or manufactured from a soft, elastic and/or a flexible material that can bend and/or flex, e.g., rubber, polystyrene, nylon, yam, mohair, plastic, polyalkenes, polypropylene, polyethylene, fluorinated polyolefins, polytetrafluoroethylene, PTFE, ePTFE, cPTFE, polyvinylidene fluoride, blends of polyvinylidene fluoride and copolymers of vinylidene fluoride and hexafluoropropene, polyamides, polyurethanes, polyisoprenes, polystyrenes, polysilicones, polycarbonates, polyetheretherketones (PEEK), polyarylether ketones (PAEK), polymethacrylic acid esters, polyacrylic acid esters, aromatic polyesters, polyimides, and/or polyamides. In some embodiments, the bristles 510 can be formed from a material of the sleeve, e.g., by cutting a series of flaps into the sleeve and/or access port, molded, extruded, or any other technique known in the art for manufacturing surface features. In some embodiments, one or more of fish scales, fins, flaps, skins, teeth, hooks, threads, and/or other examples of features known to one skilled in the art for grasping tissue can be used in lieu of, or in addition to, the structures described herein to increase friction with surrounding tissue.

[0072] During insertion of the access port 100 of the instant embodiment into the surgical site, the bristles can flex outward to protrude from the sidewall to engage surrounding tissue to retain the port at the desired location. In some embodiments, the bristles 510 can flex from

approximately 0 degrees to approximately 180 degrees relative to the sidewall 102 of the access port. The bristles 510 can include top surfaces 530 for engaging tissue. During advancement in the insertion direction A, the tissue can exert a force on the bristles 510 to flex the bristles such that the top surfaces 530 point away from the tissue to minimize friction during advancement. Movement of the access port in the opposite direction can bring the top surfaces 530 in contact with the tissue, causing the structures to adhere to tissues and create counter-friction to prevent backing out.

[0073] In use, an incision can be made in the surgical site of the patient. The access port 100 having one or more of the surface features discussed in the embodiments above can be positioned near the surgical site and advanced distally therethrough in an insertion direction A. The access port 100 can be inserted and advanced through the surgical site by pushing, via rotation, or by any other method known to one in the art for inserting instruments into a surgical site to minimize damage to surrounding tissue. During insertion and advancement, the surface features can bend, flex, and/or pivot toward the sidewall of the access port and/or away from the tissue so as to create minimal friction between the surface features and surrounding tissues to allow advancement of the access port. [0074] Once advanced to the desired location, the surface features can be deployed to engage surrounding tissue to prevent ejection of the access port. The surface features can be deployed due to friction with surrounding tissue or actively deployed, e.g., by rotation the access port 100. For example, rotation of the access port 100 relative to its longitudinal axis A1 in a first direction can deploy the surface features to engage the tissue to prevent movement of the device relative to the tissue and rotation of the access port relative to its longitudinal axis A1 in a second, opposite direction can disengage the surface features from the tissue to allow retraction of the access port 100 from the surgical site. Devices, instruments, and other materials can then be introduced into the body of the patient through the access port. At the conclusion of the procedure, the surface features can be withdrawn from the tissues and the access port 100 can advanced in a direction opposite to the insertion direction A, e.g. proximally, to remove the access port 100 from the patient. It will be appreciated that the surface features can be sufficiently manipulated to allow the port to be removed from the surgical site when intended without damaging surrounding tissues.

[0075] It should be noted that any ordering of method steps expressed or implied in the description above or in the accompanying drawings is not to be construed as limiting the disclosed methods to performing the steps in that order. Rather, the various steps of each of the methods disclosed herein can be performed in any of a variety of sequences. In addition, as the described methods are merely exemplary embodiments, various other methods that include additional steps or include fewer steps are also within the scope of the present disclosure.

[0076] The devices disclosed herein can be constructed from any of a variety of known materials. Exemplary materials include those which are suitable for use in surgical applications, including metals such as stainless steel, titanium, nickel, cobalt-chromium, or alloys and combinations thereof, polymers such as PEEK, ceramics, carbon fiber, and so forth. The various components of the devices disclosed herein can be rigid or flexible. One or more components or portions of the device can be formed from a radiopaque material to facilitate visualization under fluoroscopy and other imaging techniques, or from a radiolucent material so as not to interfere with visualization of other structures. Exemplary radiolucent materials include carbon fiber and high-strength polymers. [0077] The devices and methods disclosed herein can be used in minimally-invasive surgery and/or open surgery. While the devices and methods disclosed herein are generally described in the context of navigated surgery on a human patient, it will be appreciated that the methods and devices disclosed herein can be used in any type of surgery on a human or animal subject, in non-surgical applications, on non-living objects, and so forth.

[0078] Although specific embodiments are described above, it should be understood that numerous changes may be made within the spirit and scope of the concepts described.