Patent Description:
The present disclosure relates to microsurgical tools, and more specifically, to ophthalmic cutting devices.

Many microsurgical procedures require precision cutting and/or removal of various body tissues. For example, vitreoretinal procedures such as retinotomies, retinectomies, autologous retinal transplants, and vitrectomies typically require the cutting, removal, dissection, delamination, coagulation, or other manipulation of intraocular tissues such as the retina, vitreous humor, traction bands, and membranes.

The retina, or the innermost layer lining the back wall of the eye, is responsible for receiving, modulating, and transmitting visual stimuli from the external environment to the optic nerve, and ultimately, the visual cortex of the brain. Structurally, the retina is a complex and delicate tissue with numerous types of cells arranged in multiple cellular layers. Due to the retina's role in vision and its fragility, damage thereto may result in severe loss of vision or even permanent blindness. Therefore, cutting, removal, or other manipulation of the retina must be done with great care to avoid unwanted retinal trauma. Ophthalmic microsurgical instruments, such as vitrectomy probes, fiber optic illuminators, infusion cannulas, aspiration probes, scissors, forceps, and lasers are typically utilized during vitreoretinal surgery. These devices are generally inserted through one or more surgical incisions in the sclera near the pars plana, which are called sclerotomies. One exemplary ophthalmic surgical device includes a cutting tool having a cutting blade disposed within a tubular probe needle. The cutting blade moves reciprocally within the probe needle relative to a second blade that is fixed within the tubular needle. The moving blade cuts material, e.g., retinal or membrane tissue, in a guillotine-like motion adjacent the fixed blade.

In order to reduce potential damage to the surgical site and reduce patient recovery time, ophthalmic surgical tools, such as the cutting tool described above, are being designed in progressively smaller sizes to facilitate correspondingly smaller surgical incisions. However, despite the smaller size, avoiding unwanted trauma during vitreoretinal procedures can still be very challenging with currently available cutting tools due to the shape and/or indelicate material compositions thereof. Therefore, there is a need in the art for ophthalmic cutting devices and methods of use thereof that address the drawbacks described above. Reference is made to the documents <CIT> and <CIT> which have been cited as exemplary of the background state of the art.

The present disclosure relates to ophthalmic surgical tools, and more specifically, to ophthalmic microsurgical cutting devices and methods of use thereof. The methods described are not part of the claimed invention and described for illustrative purposes.

In certain embodiments, a cutting tool assembly is provided. The cutting tool assembly includes a first blade in a fixed position and a second blade configured to move relative to the first blade. The first blade includes a first longitudinal body portion and a first end portion extending laterally from a distal end of the first longitudinal body portion. A distal surface of the first end portion is coated with a first polymer coating. The second blade includes a second longitudinal body portion and a second end portion extending laterally from a distal end of the second longitudinal body portion. A distal surface of the second end portion includes a cutting edge, while a proximal surface thereof is coated with a second polymer coating. Longitudinal movement of the second blade facilitates cutting of a tissue by the cutting edge.

In certain embodiments, a surgical tool assembly is provided. The surgical tool includes a tubular shaft and a cutting tool assembly. The tubular shaft defines a longitudinal axis and an aperture at a first end of the tubular shaft. The cutting tool assembly is received at least partially within the tubular shaft through the aperture and extends along the longitudinal axis. The cutting tool assembly includes a first blade in a fixed position and a second blade configured to move relative to the first blade. The first blade includes a first longitudinal body portion and a first end portion extending laterally from a distal end of the first longitudinal body portion. A distal surface of the first end portion is coated with a first polymer coating. The second blade includes a second longitudinal body portion and a second end portion extending laterally from a distal end of the second longitudinal body portion. A distal surface of the second end portion includes a cutting edge, while a proximal surface thereof is coated with a second polymer coating. Longitudinal movement of the second blade facilitates cutting of a tissue by the cutting edge.

It is to be noted, however, that the appended drawings illustrate only exemplary embodiments and are therefore not to be considered limiting of its scope, and may admit to other equally effective embodiments.

In the following description, details are set forth by way of example to facilitate an understanding of the disclosed subject matter. It should be apparent to a person of ordinary skill in the field, however, that the disclosed implementations are exemplary and not exhaustive of all possible implementations. Thus, it should be understood that reference to the described examples is not intended to limit the scope of the disclosure. Any alterations and further modifications to the described devices, instruments, methods, and any further application of the principles of the present disclosure are fully contemplated as would normally occur to one skilled in the art to which the disclosure relates. In particular, it is fully contemplated that the features, components, and/or steps described with respect to one implementation may be combined with the features, components, and/or steps described with respect to other implementations of the present disclosure.

Note that, as described herein, a distal end, segment, or portion of a component refers to the end, segment, or portion that is closer to a patient's target tissue during use thereof. On the other hand, a proximal end, segment, or portion of the component refers to the end, segment, or portion that is distanced further away from the patient's target tissue.

As used herein, the term "about" may refer to a +/-<NUM>% variation from the nominal value. It is to be understood that such a variation can be included in any value provided herein.

Embodiments of the present disclosure generally relate to microsurgical cutting devices for ophthalmic procedures. As described above, currently, microsurgical cutting devices are used in a wide range of vitreoretinal procedures, including retinotomies, retinectomies, proliferative vitreoretinopathies (PVR), autologous retinal transplants, and similar procedures. However, certain existing cutting tool designs, though effective for cutting, may facilitate unwanted damage to tissues (e.g., the retina and retinal pigment epithelium (RPE)) adjacent to target cut sites due to the unrefined outer surface profiles of their cutting blades and/or the indelicate materials they are formed of.

The cutting devices described herein address the deficiencies of certain existing designs and reduce the risk of unwanted damage to peripheral tissues by providing cutting blades with curved outer surface profiles, which may further be coated, such as with a polymer coating, to further enhance the safety thereof. Accordingly, the cutting devices described herein may be utilized to more safely perform, for example: linear retinotomies to insert induced pluripotent stem cell (iPSC) derived retinal pigment epithelium (RPE) monolayers on a biodegradable scaffold for treatment of geographic atrophy from dry age-related macular degeneration (AMD); linear retinotomies to insert photoreceptor progenitor (PhRP) monolayers on biodegradable scaffolds for treatment of a variety of retinal disorders including dry AMD, long standing retinal detachment, and inherited retinal disorders such as retinitis pigmentosa (RP); circumferential retinotomies to treat PVR-related retinal detachments, e.g., by removing tissue anterior to a circumferential cut to reduce PVR recurrence rate and epiciliary tissue which can cause hypotony; autologous macular patch graft transplants to treat large macular holes, which are all very challenging with current cutting tool designs; as well as other similar procedures.

In certain embodiments described herein, a cutting tool assembly includes a first blade in a fixed position and a second blade configured to move relative to the first blade. The first blade includes a first longitudinal body portion and a first end portion extending laterally from a distal end of the first longitudinal body portion. A distal surface of the first end portion has a bowed morphology to match a curvature of a retinal surface and is further coated with a first polymer coating to reduce damage to retinal tissues (e.g., retinal pigment epithelium (RPE) or photoreceptor layer) during use thereof. The second blade includes a second longitudinal body portion and a second end portion extending laterally from a distal end of the second longitudinal body portion. A distal surface of the second end portion includes a cutting edge, while a proximal surface thereof is coated with a second polymer coating. Longitudinal movement of the second blade facilitates linear or circumferential cutting of a tissue, such as retinal or membrane tissue, for performance of ophthalmic surgical procedures such as those described above.

<FIG> illustrates a cross-sectional view of an eye <NUM> with a surgical device <NUM> at least partially inserted therein for performance of an ophthalmic surgical procedure, according to certain aspects of the present disclosure. The surgical device <NUM> is used in combination with a cutting tool assembly <NUM> for performing various vitreoretinal procedures within the eye <NUM>, including retinotomies, retinectomies, and other procedures requiring the cutting of one or more tissues of the eye <NUM>.

A number of features of the eye <NUM> are illustrated herein for reference. Generally, the eye <NUM> includes the sclera <NUM> that is attached to the retinal membrane or retina <NUM> by the choroid. The choroid includes connective tissue that attaches the retina <NUM> to the inside wall of the sclera <NUM> at the back of the eye and provides oxygen and nourishment to the outer layers of the retina <NUM>. The retina <NUM> is a delicate and complex multi-layered tissue containing photo-activated cells that transmit signals, based on visual stimuli, through the optic nerve <NUM> to the brain. The cornea <NUM> permits light to enter the eye <NUM>, the light being focused by a lens <NUM>.

The surgical device <NUM> generally includes a handpiece <NUM>, which is connected to the cutting tool assembly <NUM> at a distal end of the handpiece <NUM> for use therewith. The cutting tool assembly <NUM> consists of a tubular body <NUM> and a pair of blades <NUM> at least partially disposed in the tubular body <NUM> and extending from a distal end thereof. As illustrated, the cutting tool assembly <NUM> is introduced into an intraocular space <NUM> by a user through an opening <NUM> in the sclera <NUM>, which may be formed by a trocar blade that is positioned inside cannula <NUM>. The cannula <NUM> is configured to allow a user to insert various surgical devices into the eye <NUM> without causing damage to the surrounding tissue (e.g., sclera <NUM>). The cannula <NUM> may range in size from <NUM>-gauge to <NUM>-gauge, and the cutting tool assembly <NUM> may have corresponding dimensions to fit therethrough. In certain embodiments, the cutting tool assembly <NUM> is sized to fit through a <NUM>-gauge, <NUM>-gauge, or <NUM>-gauge cannula <NUM>.

After the cutting tool assembly <NUM> is inserted into the eye <NUM> via the cannula <NUM>, the user can move the handpiece <NUM> to vary the position and depth of the cutting tool assembly <NUM>, and in particular, the blades <NUM>, within the eye <NUM>. Once the blades <NUM> are positioned proximate to a target tissue to be cut (in this example, the blades <NUM> are positioned adjacent to the retina <NUM>), the user may operate an actuation mechanism <NUM> of the surgical device <NUM> to cause a cutting motion by the blades <NUM>, described in further detail with reference to <FIG>. In certain embodiments, the actuation mechanism <NUM> is manual actuator that can be directly manipulated by the user. In certain other embodiments, the actuation mechanism <NUM> is a pneumatic or electric actuator.

<FIG> illustrates the surgical device <NUM> in more detail. As described above, the surgical device <NUM> includes the handpiece <NUM> configured to be grasped, e.g., by a surgeon, and the actuation mechanism <NUM> operable to actuate the cutting tool assembly <NUM>. In the embodiments of <FIG> and <FIG>, the actuation mechanism <NUM> is radially pivotable relative to the handpiece <NUM>. The lever can be actuated by a finger or other portion of a user's hand while grasping the handpiece <NUM>, thus decoupling the actions of positioning and actuating the cutting tool assembly <NUM> for increased positioning precision. In certain embodiments, the surgical device <NUM> further includes a rotatable component <NUM> operable to adjust the rotational orientation of the cutting tool assembly <NUM> for improved versatility during a surgical procedure. For example, the rotatable component <NUM> may include a disc that is rotatable about a longitudinal axis A of the tubular member <NUM> of the cutting tool assembly <NUM> (represented by arrows in <FIG>).

The cutting tool assembly <NUM> couples to the handpiece <NUM> at a proximal end of the cutting tool assembly <NUM> and the distal end of the handpiece <NUM>, and may be permanently or impermanently secured thereto. For example, in certain embodiments, the cutting tool assembly <NUM> is removable from the handpiece <NUM> and interchangeable with other surgical tools. In such embodiments, the cutting tool assembly <NUM> may include one or more adapters disposed at a proximal end of the tubular body <NUM> for coupling the cutting tool assembly <NUM> with a handpiece, e.g., handpiece <NUM>. <FIG> illustrates an example adapter <NUM> disposed at the proximal end of the tubular body <NUM>.

The tubular body <NUM> of the cutting tool assembly <NUM> may be configured to be inserted into a cannula or surgical incision, e.g., during various posterior and anterior ophthalmic surgical procedures such as retinotomies and retinectomies, merely as examples. The pair of blades <NUM>, which are at least partially received within the tubular body <NUM>, extend from a distal end of the tubular body <NUM> along the longitudinal axis A. As described above, the blades <NUM> may be actuated by manipulation of the actuation mechanism <NUM> by the user. For example, depressing and/or releasing the actuation mechanism <NUM> relative to the handpiece <NUM> (represented by arrows in <FIG>) may cause the blades <NUM> to perform a cutting motion.

Turning now to <FIG>, another exemplary surgical device <NUM> is illustrated. Similar to the surgical device <NUM>, the surgical device <NUM> is an exemplary embodiment of the surgical device <NUM> for use with the cutting tool assembly <NUM>. Unlike the surgical device <NUM>, however, the surgical device <NUM> includes a handpiece <NUM> which itself acts as an actuation component for the cutting tool assembly <NUM>. As shown, the handpiece <NUM> is comprised of two housing components 428a and 428b, which may be semi-circular in shape. The housing components 428a, 428b are connected at distal ends thereof by a joint <NUM>, and are further operatively engaged with a sliding member <NUM> disposed between the housing components 428a, 428b. The sliding member <NUM> is connected to an adapter arm <NUM>, which is permanently or impermanently secured to the cutting tool assembly <NUM> and may include a rotatable component <NUM>. Compression of the housing components 428a, 428b (represented by arrows in <FIG>) activates the sliding member <NUM>, which then actuates the blades <NUM> of the cutting tool assembly <NUM> to perform a cutting motion.

<FIG> illustrate enlarged perspective views of the cutting tool assembly <NUM>, and in particular, the blades <NUM>, from opposite sides of the cutting tool assembly <NUM>, in accordance with certain embodiments of the present disclosure. Accordingly, <FIG> are herein described together for clarity.

As shown, the blades <NUM> include a first blade <NUM> and a second blade <NUM> that are each at least partially received in the tubular body <NUM> and extend along the longitudinal axis A. The first blade <NUM> may be fixed relative to the tubular body <NUM>, e.g., by welding or similar techniques. The first blade <NUM> includes a body portion <NUM> disposed along the longitudinal axis A and an end portion <NUM> laterally extending from the body portion <NUM>. The second blade <NUM> may be configured to move longitudinally within the tubular body <NUM> relative to the first blade <NUM> along a cutting path P. Similar to the first blade <NUM>, the second blade <NUM> includes a body portion <NUM> disposed along the longitudinal axis A and an end portion <NUM> laterally extending from the body portion <NUM>. The end portion <NUM> includes a cutting edge <NUM> on a distal surface <NUM> thereof. The cutting edge <NUM> may be configured to cut material, e.g., ocular tissue, disposed adjacent or against the end portion <NUM> of the first blade <NUM>. More specifically, the cutting edge <NUM> may cut material in a scissor-like cutting motion, in cooperation with the end portion <NUM> of the first blade <NUM>. In certain examples, the end portion <NUM> is pressed against an ocular tissue, e.g., a retinal layer, while the cutting edge <NUM> cuts a membrane or layer disposed between the cutting edge <NUM> and the end portion <NUM>.

The first blade <NUM> and the second blade <NUM> may include relatively thin neck portions <NUM>, <NUM>, respectively, disposed between the end portions <NUM>, <NUM>, and the body portions <NUM>, <NUM>. The utilization of at least the thin neck portion <NUM> may facilitate movement of the second blade <NUM> relative to the first blade <NUM> while also allowing a cutting surface S that can fully engage with the cutting edge <NUM>. In other terms, the neck portion <NUM> defines a lateral width W<NUM> that is smaller than a lateral width W<NUM> of the cutting edge <NUM>. Any wear, e.g., as caused by friction between the cutting edge <NUM> and the first blade <NUM>, may also be reduced while allowing a relatively larger width of the cutting edge <NUM> to be applied to a material, e.g., tissue, for cutting.

As shown in <FIG>, one or both end portions <NUM>, <NUM> of the blades <NUM>, <NUM> may include rounded, curved, or bowed surfaces to reduce the risk of undesired damage to intraocular tissues during ophthalmic surgical procedures. For example, the end portion <NUM> may include a bowed distal surface <NUM> and/or a bowed proximal surface <NUM>. In certain embodiments, the bowed distal surface <NUM> is shaped to correspond with a radial curvature of, e.g., the retina and/or RPE, thus enabling the first blade <NUM> to be pressed upon a retinal layer during a surgical procedure with reduced risk of damaging any overlying or underlying membranes or layers, e.g., the photoreceptor layer and RPE. In certain embodiments, the end portion <NUM> of the second blade <NUM> has a corresponding morphology to the end portion <NUM>, and includes a bowed distal surface <NUM> and/or a bowed proximal surface <NUM> as well. In embodiments where both proximal and distal surfaces of each end portion <NUM>, <NUM> are bowed, as shown in <FIG>, the end portions <NUM>, <NUM> define a generally "hook" shape extending laterally, e.g., relative to the longitudinal axis A. In further embodiments, the end portions <NUM>, <NUM> include rounded tips <NUM>, <NUM>, respectively, between proximal and distal surfaces thereof.

To further reduce the risk of damage to ocular tissues when using the cutting tool assembly <NUM>, one or more surfaces of the end portions <NUM>, <NUM> may also be coated with a coating <NUM>, which provides a softer surface for contacting against ocular tissues. For example, in certain embodiments, at least the distal surface <NUM> of the end portion <NUM>, which may be pressed against an ocular structure (e.g., the retina) during an ophthalmic surgical procedure, is coated with the coating <NUM>. In further embodiments, the proximal surface <NUM> of the end portion <NUM>, and/or the proximal surface <NUM> of the end portion <NUM>, are coated with the coating <NUM>. Exemplary materials for the coating <NUM> generally include materials that are neither lipophilic nor hydrophilic, thus having a low surface activity and reducing the likelihood of ocular tissue cells (e.g., retinal cells such as RPE cells, rods, and cones) adhering to the cutting tool assembly <NUM>. For example, the coating <NUM> may comprise or be formed of polymeric materials such as polytetrafluoroethylene (PTFE), fluorinated ethylene propylene (FEP), polyvinylidene fluoride (PVDF), rerfluoroalkoxy (PFA), ethylene tetrafluoroethylene (ETFE), ethylene chlorotrifluoroethylene (ECTFE), tetrafluoroethylene perfluoromethylvinylether (MFA), polychlorotrifluoroethylene (PCTFE), polytetrafluoroethylene (PEEK), terpolymer of tetrafluoroethylene (THV), and the like. In embodiments where multiple surfaces of the end portions <NUM>, <NUM> are coated with the coating <NUM>, one or more of the coated surfaces may have coatings comprising or formed of the same or different materials, e.g., polymers.

<FIG> illustrates a cross-sectional view of the tubular body <NUM> and blades <NUM>, in accordance with certain embodiments of the present disclosure. More specifically, <FIG> illustrates a cross-sectional view of the body portions <NUM>, <NUM> of the first blade <NUM> and second blade <NUM>, respectively. As shown, the cross-sections of the body portions <NUM>, <NUM>, as viewed normal to the longitudinal axis A of the tubular body <NUM>, are each defined by inner (i.e., centrally disposed) edges <NUM> and <NUM>, as well as outer (i.e., lateral) edges <NUM> and <NUM> extending between opposing sides of the inner edges. Further, though the cross sections of body portions <NUM>, <NUM> in <FIG> are symmetrical with respect to each other, each of the cross sections is generally asymmetrical with respect to a line B that is substantially parallel to the inner edges <NUM>, <NUM>. The asymmetrical cross-sections of each body portion <NUM>, <NUM> may facilitate an enlarged section modulus and thus, improved strength, as compared to blades having a quadrangular-shaped cross-section.

The inner edges <NUM>, <NUM> of the body portions <NUM>, <NUM> are generally adjacent to one another and extend across substantially the entire inner diameter of the tubular member <NUM>. In certain embodiments, the inner edges <NUM>, <NUM> have similar lengths and cross-sectional shapes. Alternatively, the inner edges <NUM>, <NUM>, and/or the blades <NUM>, <NUM> in general, may be different sizes, e.g., where one of the blades is enlarged for more secure positioning within the tubular body <NUM>. The outer edges <NUM>, <NUM> of each body portion <NUM>, <NUM> are generally curved or rounded in shaped, similar to the surfaces of the end portions <NUM>, <NUM>, to reduce the risk of damage when using the cutting tool assembly <NUM> during an ophthalmic surgical procedure. However, in certain embodiments, the outer edges <NUM>, <NUM> may include one or more linear surfaces. Note that the cross-sections of the body portions <NUM>, <NUM> depicted in <FIG> are but one embodiment thereof, and that other geometries are also contemplated. For example, in certain embodiments, the cross-sections of body portions <NUM>, <NUM> may be asymmetrical with respect to each other, and/or the body portions <NUM>, <NUM> may be substantially quadrangular.

<FIG> illustrates an orthogonal front view of the tubular body <NUM> and blades <NUM>, in accordance with certain embodiments of the present disclosure. More specifically, <FIG> illustrates an orthogonal front view of the end portions <NUM>, <NUM> of the first blade <NUM> and second blade <NUM>, respectively. Accordingly, the distal surface <NUM> of the blade <NUM>, shown with coating <NUM>, and the distal surface <NUM> of the blade <NUM>, shown with cutting edge <NUM>, are illustrated. Similar to the body portions <NUM>, <NUM>, the end portions <NUM>, <NUM>, as viewed normal to the longitudinal axis A of the tubular body <NUM>, are each laterally defined by the inner edges <NUM> and <NUM>, as well as the outer edges <NUM> and <NUM>. However, in certain embodiments, along the end portions <NUM>, <NUM>, the inner edges <NUM>, <NUM> and/or outer edges <NUM>, <NUM> may have different lateral dimensions (e.g., lengths or widths) as compared to the same along different portions of the body portions <NUM>, <NUM>. In such embodiments, the diminished lateral dimensions of the end portions <NUM>, <NUM> relative to the body portions <NUM>, <NUM> may reduce the risk of damage to ocular tissues when using the cutting tool assembly <NUM>, thus providing improved safety therewith as compared to other cutting tools.

In summary, embodiments of the present disclosure generally relate to microsurgical cutting devices for ophthalmic procedures. In particular, the embodiments herein provide an improved cutting tool design with one or more cutting blades having a curved outer based on a curvature of a target tissue, e.g., the retina and/or RPE. Even further, the curved surfaces of the one or more cutting blades may be coated with a polymer coating, thus providing a softer surface for contacting against ocular tissues. Accordingly, the described embodiments enable safer performance of ophthalmic surgical procedures, such as retinotomies and retinectomies, with reduced risk of unwanted damage to periphery tissues, as compared to conventional tools and devices.

The foregoing description is provided to enable any person skilled in the art to practice the various embodiments described herein. Various modifications to these embodiments will be readily apparent to those skilled in the art, and the generic principles defined herein may be applied to other embodiments. Thus, the claims are not intended to be limited to the embodiments shown herein, but are to be accorded the full scope consistent with the language of the claims.

Within a claim, reference to an element in the singular is not intended to mean "one and only one" unless specifically so stated, but rather "one or more. " The word "exemplary" is used herein to mean "serving as an example, instance, or illustration.

The following paragraphs set out example arrangements according to the specification and are provided to assist in understanding the invention.

Example Arrangement <NUM>: A cutting tool assembly, comprising: a first blade in a fixed position, the first blade comprising: a first longitudinal body portion; and a first end portion extending laterally from a distal end of the first longitudinal body portion, the first end portion comprising a distal surface coated with a first polymer coating; and a second blade configured to move relative to the first blade, the second blade comprising: a second longitudinal body portion; and a second end portion extending laterally from a distal end of the second longitudinal body portion, the second end portion comprising a distal surface having a cutting edge and a proximal surface coated with a second polymer coating, wherein longitudinal movement of the second blade facilitates cutting of a tissue by the cutting edge.

The cutting tool assembly described above, wherein the second polymer coating comprises polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

The cutting tool assembly described above, wherein a proximal surface of the first end portion is coated with a third polymer coating.

: The cutting tool assembly described above, wherein the third polymer coating comprises polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

: The cutting tool assembly described above, wherein the first polymer coating and the second polymer coating comprise the same polymer.

Example Arrangement <NUM>: A surgical tool, comprising: a tubular shaft defining a longitudinal axis, the tubular shaft further defining an aperture at a first end of the tubular shaft; and a pair of blades received at least partially within the tubular shaft through the aperture and extending along the longitudinal axis, the pair of blades comprising: a first blade in a fixed position relative to the tubular shaft, the first blade comprising: a first body portion; and a first end portion extending laterally from a distal end of the first body portion, the first end portion comprising a distal surface coated with a first polymer coating; and a second blade configured to move relative to the first blade and the tubular shaft along the longitudinal axis, the second blade comprising: a second body portion; and a second end portion extending laterally from a distal end of the second body portion, the second end portion comprising a distal surface having a cutting edge and a proximal surface coated with a second polymer coating.

The surgical tool described above, wherein the first polymer coating and the second polymer coating comprise the same polymer.

The surgical tool described above, the first polymer coating and the second polymer coating comprise polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

The surgical tool described above, wherein the first end portion further comprises a proximal surface coated with a third polymer coating.

The surgical tool described above, wherein the third polymer coating comprises polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP).

The surgical tool described above, wherein the surgical tool is configured to fit through a <NUM>-gauge cannula.

The surgical tool described above, further comprising: a handle connected to the tubular shaft, the handle comprising a lever configured to move the second blade along the longitudinal axis upon manipulation of the lever while the first blade remains stationary.

Claim 1:
A cutting tool assembly (<NUM>), comprising:
a first blade (<NUM>) in a fixed position, the first blade comprising:
a first longitudinal body portion (<NUM>); and
a first end portion (<NUM>) extending laterally from a distal end of the first longitudinal body portion (<NUM>), the first end portion (<NUM>) comprising a distal surface (<NUM>) coated with a first polymer coating (<NUM>); and
a second blade (<NUM>) configured to move relative to the first blade (<NUM>), the second blade comprising:
a second longitudinal body portion (<NUM>); and
a second end portion (<NUM>) extending laterally from a distal end of the second longitudinal body portion (<NUM>), the second end portion (<NUM>) comprising a distal surface (<NUM>) having a cutting edge (<NUM>) and a proximal surface (<NUM>) coated with a second polymer coating (<NUM>), wherein longitudinal movement of the second blade (<NUM>) facilitates cutting of a tissue by the cutting edge (<NUM>).