Patent Description:
The present invention relates to a lung access procedure, such as a lung biopsy, and, more particularly, to an introducer cannula having a pleural access liner for use in crossing pleural layers.

Pneumothorax is a problematic complication of the lung biopsy procedure where air or fluid is allowed to pass into the pleural space as a result of the puncture of the parietal pleura and visceral pleura. Pneumothorax and, more so, pneumothorax requiring chest tube placement, are significant concerns for clinicians performing, and patients undergoing, percutaneous lung biopsies. The incidence of pneumothorax in patients undergoing percutaneous lung biopsy has been reported to be anywhere from <NUM>-<NUM>%, with an average of around <NUM>%. On average, <NUM>% of all percutaneous lung biopsies result in pneumothorax requiring a chest tube to be placed, which results in an average hospital stay of <NUM> days.

Factors that increase the risk of pneumothorax include increased patient age, obstructive lung disease, increased depth of a lesion, multiple pleural passes, increased time that an access needle lies across the pleura, and traversal of a fissure. Pneumothorax may occur during or immediately after the procedure, which is why typically a CT scan of the region is performed following removal of the needle. Other, less common, complications of percutaneous lung biopsy include hemoptysis (coughing up blood), hemothorax (a type of pleural effusion in which blood accumulates in the pleural cavity), infection, and air embolism. <CIT> discloses a puncture needle having a swellable outer layer.

What is needed in the art is an introducer cannula having a pleural access liner for use in crossing pleural layers, which aids in the prevention of pneumothorax.

The present invention, as claimed in claim <NUM>, provides an introducer cannula having a pleural access liner for use in crossing pleural layers, which aids in the prevention of pneumothorax.

The invention, in one form, is directed to an introducer cannula for use in crossing pleural layers, which includes an elongate tubular member and a pleural access liner. The elongate tubular member has a proximal end, a distal end, and a side wall that longitudinally extends between the proximal end and the distal end. The side wall has an outer surface and an inner surface, wherein the inner surface defines a lumen. The pleural access liner is made of a swellable and bioabsorbable material that swells when hydrated. The pleural access liner has a shape of an elongate tube and the pleural access liner has an elongate opening that surrounds an outer surface portion of the outer surface of the elongate tubular member.

The outer surface of the side wall of the elongate tubular member has a first outer surface portion having a first diameter and a second outer surface having a second diameter that is less than the first diameter. The second outer surface portion of the side wall defines an elongate exterior recess that extends around the elongate tubular member. The pleural access liner resides in and surrounds the elongate exterior recess of the side wall of the elongate tubular member.

An advantage of the present invention is that the pleural access liner facilitates access across pleura layers to aid in preventing pneumothorax before, or coincident with, and after the performing of a lung biopsy.

Another advantage of the present invention is that the pleural access liner is made of a swellable and bioabsorbable material that is resorbed by the patient's body over time as the tissue heals to close the biopsy access opening. Methods of surgery are not claimed.

Corresponding reference characters indicate corresponding parts throughout the several views. The exemplifications set out herein illustrate at least one embodiment of the invention, and such exemplifications are not to be construed as limiting the scope of the invention in any manner.

Referring now to the drawings, and more particularly to <FIG>, there is shown a pleural layers crossing system <NUM>, which includes an introducer cannula <NUM> having a pleural access liner <NUM> for use in crossing pleural layers in a lung access procedure, and a stylet assembly <NUM>. Introducer cannula <NUM> and stylet assembly <NUM> are arranged along a longitudinal axis <NUM>, such that introducer cannula <NUM> and stylet assembly <NUM> are coaxial.

Stylet assembly <NUM> includes a stylet <NUM>-<NUM> and a stylet handle <NUM>-<NUM>. Stylet <NUM>-<NUM> has a piercing tip <NUM>-<NUM>. Stylet handle <NUM>-<NUM> is fixedly connected to a proximal end portion of stylet <NUM>-<NUM>. The term "fixedly connected" means a coupling between two or more components wherein the respective components are not readily separated from each other. For example, the fixed connection of stylet handle <NUM>-<NUM> to stylet <NUM>-<NUM> may be achieved, for example, by adhesive, weld, press fit, or screw connection.

Introducer cannula <NUM> includes a handle body <NUM> and an elongate tubular member <NUM>. Elongate tubular member <NUM> has a proximal end <NUM>-<NUM>, a distal end <NUM>-<NUM>, a distal end portion <NUM>-<NUM>, a lumen <NUM>-<NUM>, and a side wall <NUM>-<NUM>. Side wall <NUM>-<NUM> longitudinally extends between proximal end <NUM>-<NUM> and distal end <NUM>-<NUM>, e.g., along an entire length of elongate tubular member <NUM>. Side wall <NUM>-<NUM> has an outer surface <NUM>-<NUM> and an inner surface <NUM>-<NUM> that surrounds and defines lumen <NUM>-<NUM>.

Handle body <NUM> is fixedly connected to elongate tubular member <NUM>, e.g., at a location distal to proximal end <NUM>-<NUM>, wherein lumen <NUM>-<NUM> passes though handle body <NUM>. In other words, lumen <NUM>-<NUM> extends through handle body <NUM>, and extends from proximal end <NUM>-<NUM> of elongate tubular member <NUM> to distal end <NUM>-<NUM> of elongate tubular member <NUM>, e.g., along an entire length of elongate tubular member <NUM>.

In the present embodiment, with particular reference to <FIG>, outer surface <NUM>-<NUM> of side wall <NUM>-<NUM> of elongate tubular member <NUM> has a first outer surface portion <NUM>-<NUM> having a first diameter <NUM>-<NUM> and a second outer surface portion <NUM>-<NUM> having a second diameter <NUM>-<NUM> that is less than the first diameter <NUM>-<NUM>, wherein the second outer surface portion <NUM>-<NUM> of the side wall <NUM>-<NUM> defines an elongate exterior recess <NUM> in side wall <NUM>-<NUM> that extends around elongate tubular member <NUM>. In the present embodiment, elongate exterior recess <NUM> of the side wall <NUM>-<NUM> extends around an entirety of elongate tubular member <NUM>, and has a length <NUM>. The length <NUM> of elongate exterior recess <NUM> may be completely, or alternatively partially, longitudinally filled with pleural access liner <NUM>. In some implementations, for example, the length <NUM> of elongate exterior recess <NUM> may be in a range of <NUM> to <NUM> centimeters.

Referring also to <FIG>, in the present embodiment, pleural access liner <NUM> is a bioabsorbable member that is initially in a dehydrated state (see <FIG>), and which is configured to hydrate and swell (see <FIG>) upon contact with a fluid, e.g., upon contact with human bodily fluids during a lung access procedure. Referring again also to <FIG>, pleural access liner <NUM> may be configured as a swellable and bioabsorbable elongate cylindrical layer that is coupled to outer surface <NUM>-<NUM> of elongate tubular member <NUM>, wherein the coupling of pleural access liner <NUM> to outer surface <NUM>-<NUM> of elongate tubular member <NUM> may be a friction fit.

In the present embodiment, with particular reference to <FIG>, pleural access liner <NUM> has a shape, e.g., a cylindrical shape, and includes an elongate tube <NUM>-<NUM> having an elongate opening <NUM>-<NUM>. Elongate opening <NUM>-<NUM>, i.e., an elongate volume, is sized and shaped, e.g., having a circular cross-section, to surround outer surface <NUM>-<NUM> of elongate tubular member <NUM> in a friction fit. More particularly, referring again also to <FIG>, in the present embodiment elongate opening <NUM>-<NUM> is sized and shaped to surround second outer surface portion <NUM>-<NUM> at elongate exterior recess <NUM> of elongate tubular member <NUM>, such that pleural access liner <NUM> (a bioabsorbable member) resides in and radially surrounds elongate exterior recess <NUM> of side wall <NUM>-<NUM> of elongate tubular member <NUM>. For example, pleural access liner <NUM>, as a bioabsorbable member, may radially extend around an entirety of elongate exterior recess <NUM> of the side wall <NUM>-<NUM> of elongate tubular member <NUM>, and may longitudinally extend along an entirety of the length <NUM> of elongate exterior recess <NUM>.

Referring to <FIG>, for example, when pleural access liner <NUM> is in the non-deployed (e.g. dehydrated) state, e.g., prior to insertion into a patient, pleural access liner <NUM> is initially a dehydrated bioabsorbable material that radially extends around, e.g., is slipped over, outer surface <NUM>-<NUM> of elongate tubular member <NUM>, so as to be carried by elongate tubular member <NUM> for deployment. In an initial dehydrated state, a diameter of pleural access liner <NUM> may be substantially equal to the first diameter <NUM>-<NUM> of first outer surface portion <NUM>-<NUM> of elongate tubular member <NUM> of introducer cannula <NUM>. Pleural access liner <NUM> may be made of at least one of collagen, silk fibroin, polyethylene glycol, hydroxypropyl methylcellulose, dehydrated gelatin, and starch. Accordingly, in some embodiments, pleural access liner <NUM> may be made of a polysaccharide.

In the present embodiment, for example, elongate tube <NUM>-<NUM> of pleural access liner <NUM> may be pre-formed to include elongate opening <NUM>-<NUM>, and may be made of a foam material. During assembly, elongate tubular member <NUM> is inserted through elongate opening <NUM>-<NUM> such that elongate tube <NUM>-<NUM> is in friction contact with outer surface <NUM>-<NUM> of elongate tubular member <NUM>, and more particularly, is in friction contact with second outer surface portion <NUM>-<NUM> in elongate exterior recess <NUM> of elongate tubular member <NUM>. The foam material may be made of, or made to include, at least one of collagen, silk fibroin, polyethylene glycol, hydroxypropyl methylcellulose, dehydrated gelatin, and starch (or other polysaccharide), which swells when hydrated. In some embodiments, the pre-formed elongate tube <NUM>-<NUM> forming pleural access liner <NUM> may be, for example, a tube of woven or electrospun fibers.

In an alternative embodiment, for example, pleural access liner <NUM> may be a powder coating coupled to, e.g., adhered to, outer surface <NUM>-<NUM> of elongate tubular member <NUM> to form an elongate swellable cylindrical layer around outer surface <NUM>-<NUM> of elongate tubular member <NUM>. For example, the powder coating forming pleural access liner <NUM> may be coupled to second outer surface portion <NUM>-<NUM> at elongate exterior recess <NUM> of elongate tubular member <NUM>, and applied to radially surround elongate exterior recess <NUM> of side wall <NUM>-<NUM> of elongate tubular member <NUM>. Stated differently, the powder coating coupled to the outer surface <NUM>-<NUM> of elongate tubular member <NUM> may extend around an entirety of elongate exterior recess <NUM> of side wall <NUM>-<NUM> of elongate tubular member <NUM>.

In the powder coating embodiment, the powder coating forming pleural access liner <NUM> is made of, or made to include, at least one of collagen, silk fibroin, polyethylene glycol, hydroxypropyl methylcellulose, dehydrated gelatin, and starch (or other polysaccharide), which swells when hydrated.

Referring again to <FIG>, in some embodiments, it may be desired to confirm a deployed location of pleural access liner <NUM>, wherein the confirmation may be determined by imaging, e.g., X-ray imaging. Accordingly, optionally, pleural access liner <NUM> may include a marking material or feature, e.g., a radiopaque material <NUM>. Radiopaque material <NUM> may be, for example, a radiopaque substance (e.g., a barium composition) or a metallic element (e.g., stainless steel element).

<FIG> depicts a portion of a chest wall <NUM> and lung <NUM> of a patient, and shows pleural layers crossing system <NUM> having introducer cannula <NUM> and pleural access liner <NUM> in a deployed state, prior to hydration of pleural access liner <NUM>. To achieve the deployed state depicted in <FIG>, a stylet <NUM>-<NUM> is inserted through lumen <NUM>-<NUM> of introducer cannula <NUM> (see <FIG>), with a piercing tip <NUM>-<NUM> of stylet <NUM>-<NUM> protruding from distal end <NUM>-<NUM> of elongate tubular member <NUM> of introducer cannula <NUM> (see <FIG>, and <FIG>).

Referring again to <FIG>, stylet <NUM>-<NUM> in combination with introducer cannula <NUM> (carrying pleural access liner <NUM>) are inserted into the patient to form an access opening <NUM> to the interior of lung <NUM>. In particular, access opening <NUM> is formed between adjacent ribs <NUM>-<NUM>, <NUM>-<NUM> in the rib cage of chest wall <NUM>, and extends though the parietal pleura <NUM>, the pleural space <NUM>, and the visceral pleura <NUM> to provide access to the interior of lung <NUM>. Once introducer cannula <NUM> and pleural access liner <NUM> enters into the lung parenchyma, it may be confirmed, e.g., through imaging, that pleural access liner <NUM> is positioned so as to cross parietal pleura <NUM>, the pleural space <NUM>, and the visceral pleura <NUM>. Fluid in and around access opening <NUM> hydrates pleural access liner <NUM>, such that pleural access liner <NUM> swells (see also <FIG>) and seals the region between parietal pleura <NUM> and visceral pleura <NUM> along access opening <NUM>, so as to aid in preventing pneumothorax.

A lung access procedure, such as a lung biopsy, may be carried out by removing stylet <NUM>-<NUM> from lumen <NUM>-<NUM> of elongate tubular member <NUM> of introducer cannula <NUM>, and then inserting a lung biopsy device, e.g., a biopsy probe, through lumen <NUM>-<NUM> of elongate tubular member <NUM> of introducer cannula <NUM> and into the lung. At a conclusion of the lung access procedure, the lung biopsy device may be removed from elongate tubular member <NUM> of introducer cannula <NUM>. Elongate tubular member <NUM> of introducer cannula <NUM> then may be removed from pleural access liner <NUM>, such that pleural access liner <NUM> remains in access opening <NUM> to block air and fluid entry into pleural space <NUM>, so as to aid in preventing pneumothorax. Upon removal of elongate tubular member <NUM> from pleural access liner <NUM>, pleural access liner <NUM> may undergo further swelling to close elongate opening <NUM>-<NUM> of pleural access liner <NUM>.

In some implementations, following the swelling of pleural access liner <NUM> during and following deployment, the coefficient of friction between pleural access liner <NUM> and access opening <NUM> of the patient may exceed the coefficient of friction between pleural access liner <NUM> and elongate tubular member <NUM> of introducer cannula <NUM>, such that as elongate tubular member <NUM> of introducer cannula <NUM> is retracted from access opening <NUM>, pleural access liner <NUM> remains in position in access opening <NUM>.

However, it is contemplated that in some implementations, it may be desirable to provide a mechanical aid to assist in the removal of elongate tubular member <NUM> of introducer cannula <NUM> from pleural access liner <NUM>. For example, with further reference to <FIG>, prior to deployment, a removal tool <NUM>, e.g., in the form of an outer tube <NUM>-<NUM> having a lumen <NUM>-<NUM>, may be positioned over elongate tubular member <NUM> at a location proximal to pleural access liner <NUM>, e.g., between handle body <NUM> of introducer cannula <NUM> and elongate exterior recess <NUM> of elongate tubular member <NUM> that carries pleural access liner <NUM>.

Following deployment and swelling of pleural access liner <NUM> in the patient, removal tool <NUM> may be slidably distally advanced into contact (if not already in contact) with pleural access liner <NUM> to aid in maintaining the position of pleural access liner <NUM> as elongate tubular member <NUM> is proximally withdrawn from removal tool <NUM> and pleural access liner <NUM>. For example, removal tool <NUM> may be grasped by one hand of a user to maintain the fixed position of removal tool <NUM> in contact with pleural access liner <NUM>, and the user may also grasp handle body <NUM> of introducer cannula <NUM> with the user's other hand. The user then pulls handle body <NUM> proximally to in turn proximally withdraw elongate tubular member <NUM> from removal tool <NUM> to leave pleural access liner <NUM> in its position in the access opening <NUM> of the patient. Thereafter, removal tool <NUM> may be removed from the patient and discarded.

The following items also relate to the disclosure :.

In one form, the disclosure relates to an introducer cannula configured for crossing pleural layers / for use in crossing pleural layers. The introducer cannula may comprise an elongate tubular member and a pleural access liner. The elongate tubular member may have a proximal end, a distal end, and a side wall that longitudinally extends between the proximal end and the distal end, wherein the side wall has an outer surface and an inner surface, and wherein the inner surface defines a lumen. The pleural access liner may be made of a swellable and bioabsorbable material that is configured to swell when hydrated. The pleural access liner may have a shape of an elongate tube. The pleural access liner may have an optionally elongate opening that surrounds an outer surface portion of the outer surface of the elongate tubular member.

In some embodiments, the outer surface of the side wall of the elongate tubular member may have a first outer surface portion having a first diameter and a second outer surface portion having a second diameter that is less than the first diameter, wherein the second outer surface portion of the side wall defines an elongate exterior recess that extends around the elongate tubular member. The pleural access liner may reside in and surround the elongate exterior recess of the side wall of the elongate tubular member.

In any of the embodiments, the pleural access liner may be (initially, i.e. before use) a dehydrated material that radially extends around the outer surface of the elongate tubular member.

Optionally, in some embodiments, the pleural access liner may be an elongate cylindrical layer coupled to the outer surface of the elongate tubular member.

Optionally, in some embodiments, the pleural access liner may be a powder coating coupled to the outer surface of the elongate tubular member.

Optionally, the pleural access liner may be made of a polysaccharide.

Optionally, the pleural access liner may be made of at least one of collagen, silk fibroin, polyethylene glycol, hydroxypropyl methylcellulose, dehydrated gelatin, and starch.

Optionally, in some embodiments, the pleural access liner may be a pre-formed tube made of a foam material.

Optionally, in some embodiments, the pleural access liner may be a tube of woven or electrospun fibers.

Optionally, the pleural access liner may include a radiopaque material.

Optionally, the pleural access liner may be configured to be removed from the elongate tubular member.

In another form, the disclosure relates to an introducer cannula configured for crossing pleural layers / for use in crossing pleural layers, comprising an elongate tubular member and a bioabsorbable member. The elongate tubular member may have a proximal end, a distal end, and a side wall that longitudinally extends between the proximal end and the distal end, wherein the side wall has an inner surface that defines a lumen. The side wall may have a first outer surface portion having a first diameter and a second outer surface portion having a second diameter that is less than the first diameter, wherein the second outer surface portion of the side wall defines an elongate exterior recess of the side wall that extends around an entirety of the elongate tubular member. The bioabsorbable member may be positioned in the elongate exterior recess of the side wall of the tubular member. The bioabsorbable material may be configured to swell upon contact with a fluid.

In the embodiment of the preceding paragraph, the bioabsorbable member optionally may radially extend around an entirety of the elongate exterior recess of the side wall of the elongate tubular member.

Optionally, in some embodiments, the bioabsorbable member may be an elongate cylindrical layer coupled to the outer surface of the elongate tubular member and which extends around an entirety of the elongate exterior recess of the side wall of the elongate tubular member.

Optionally, in some embodiments, the bioabsorbable member may be a powder coating coupled to the outer surface of the elongate tubular member and which extends around an entirety of the elongate exterior recess of the side wall of the elongate tubular member.

Optionally, the bioabsorbable member may be made of a polysaccharide.

Optionally, the bioabsorbable member may be made of at least one of collagen, silk fibroin, polyethylene glycol, hydroxypropyl methylcellulose, dehydrated gelatin, and starch.

Optionally, in some embodiments, the bioabsorbable member may be a pre-formed tube made of a foam material.

Optionally, in some embodiments, the bioabsorbable member may be a tube of woven or electrospun fibers.

Optionally, the bioabsorbable member may include a radiopaque material.

Optionally, the bioabsorbable member may be configured to be removable from the elongate tubular member.

As used herein, "substantially," "generally," and other words of degree are relative modifiers intended to indicate permissible variation from the characteristic so modified. It is not intended to be limited to the absolute value or characteristic which it modifies but rather possessing more of the physical or functional characteristic than its opposite, and approaching or approximating such a physical or functional characteristic.

Claim 1:
An introducer cannula (<NUM>) for use in crossing pleural layers, comprising:
an elongate tubular member (<NUM>) having a proximal end (<NUM>-<NUM>), a distal end (<NUM>-<NUM>), and a side wall (<NUM>-<NUM>) that longitudinally extends between the proximal end (<NUM>-<NUM>) and the distal end (<NUM>-<NUM>), the side wall (<NUM>-<NUM>) having an outer surface (<NUM>-<NUM>) and an inner surface (<NUM>-<NUM>), wherein the inner surface (<NUM>-<NUM>) defines a lumen (<NUM>-<NUM>),
wherein the outer surface (<NUM>-<NUM>) of the side wall (<NUM>-<NUM>) of the elongate tubular member (<NUM>) has a first outer surface portion (<NUM>-<NUM>) having a first diameter (<NUM>-<NUM>) and a second outer surface portion (<NUM>-<NUM>) having a second diameter (<NUM>-<NUM>) that is less than the first diameter (<NUM>-<NUM>), wherein the second outer surface portion (<NUM>-<NUM>) of the side wall (<NUM>-<NUM>) defines an elongate exterior recess (<NUM>) that extends around the elongate tubular member (<NUM>); and
a pleural access liner (<NUM>) made of a swellable and bioabsorbable material that swells when hydrated, wherein the pleural access liner (<NUM>) has a shape of an elongate tube (<NUM>-<NUM>) and the pleural access liner (<NUM>) has an elongate opening (<NUM>-<NUM>) that surrounds an outer surface portion (<NUM>-<NUM>) of the outer surface (<NUM>-<NUM>) of the elongate tubular member (<NUM>), wherein the pleural access liner (<NUM>) resides in and surrounds the elongate exterior recess (<NUM>) of the side wall (<NUM>-<NUM>) of the elongate tubular member (<NUM>).