Systems and methods for coupling and decoupling a catheter

A drainage stent delivery system is disclosed. The system can include a catheter body, a stent member, and a coupling member. The coupling member is configured to selectively couple and decouple the catheter body and the stent member. The coupling member can include a first connector, a second connector, and a telescoping connector. A tab of the first connector is configured to be received by a slot of the second connector when the first and second connectors are coupled. The telescoping connector can displace the tab radially outward to be received by the slot. The tab is biased radially inward when the telescoping connector is displaced. When coupled, the catheter body and the stent member are rotationally fixed.

TECHNICAL FIELD

The present disclosure relates generally to devices and methods to selectively couple tubular members, particularly in medical devices. More specifically, the present disclosure relates to drainage stent delivery systems comprising a catheter and a stent that can be percutaneously inserted into a patient, after which the stent can be remotely decoupled from the catheter.

DETAILED DESCRIPTION

Drainage stents can be used to drain fluid from various cavities and/or organs within a patient. In certain instances, a drainage stent is a medical device used within a patient population that experience one or more complications associated with the urinary system, including the kidneys, ureters, and/or bladder. In some instances, complications may affect urinary flow and how these organs handle this function. These complications range from decreased urine flow to swelling of the kidneys or bladder. Many of these conditions are adversely impacted by the formation of kidney stones. To alleviate urinary system complications, a drainage stent delivery system may be used to deliver a ureteral stent to within the bladder, one or both of the kidneys, and/or one or both of the ureters.

The drainage stent delivery system can include a catheter body, a drainage stent member, and a coupling member. The coupling member is configured to selectively couple and decouple the drainage stent member from the catheter body. The coupling member is also configured to facilitate rotation of the catheter body and the stent member in a 1:1 ratio, such as while the system is being delivered into a patient. In other words, when coupled, the catheter body and the stent member can be rotationally fixed. In certain embodiments, the coupling member can include a first or proximal connector coupled to a distal end of the catheter body, a distal or second connector coupled to a proximal end of the stent member, and a telescoping connector slidably coupled to the first and second connectors. The first connector includes a tab configured to be received by a slot of the second connector. The telescoping connector displaces the tab radially outward to be disposed within the slot when the catheter body and the stent member are coupled together. To decouple the stent member from the catheter body, the telescoping connector is retracted from the first and second connectors, the tab is biased radially inward to displace the tab from the slot, and the catheter body and the stent member can be separated.

In an exemplary use, the drainage stent delivery system can be percutaneously inserted into a patient's body such that a distal end of the drainage stent is positioned within the patient's bladder and the proximal end is positioned within the patient's kidney. A body of the stent member can be disposed in the patient's ureter between the kidney and the bladder. The stent member can be used to drain the kidney when there is a blockage or restriction of the ureter. Following a period of time, for example two weeks, to allow stabilization of the stent member, the catheter body may be remotely decoupled from the stent member, by retracting a cable coupled to the telescoping connector, and removed from the patient without surgical intervention. In some embodiments, the stent member may include retention features, for example pigtails, at the proximal and distal ends.

In other applications, the drainage stent delivery system may be used to drain bile from the patient's liver or gall bladder into the patient's small intestine, where the stent member is disposed within a blocked or restricted bile duct. In still other applications, the drainage stent delivery system may be used to drain any suitable organ of the patient where a natural drainage tube or duct is blocked or restricted. For example, the drainage stent delivery system may be used to drain fluid from a patient's cranial cavity, pericardial cavity, pleural cavity, etc.

It will be appreciated that various features are sometimes grouped together in a single embodiment, figure, or description thereof for the purpose of streamlining the disclosure. Many of these features may be used alone and/or in combination with one another.

The directional terms “distal” and “proximal” are given their ordinary meaning in the art. That is, the distal end of a medical device means the end of the device furthest from the practitioner during use. The proximal end refers to the opposite end, or the end nearest the practitioner during use. As specifically applied to the drainage stent delivery system, the proximal end of the system refers to the end that extends from the patient's body and the distal end refers to the opposite end, the end disposed within the patient's organ to be drained. For example, the patient's bladder. Thus, if at one or more points in a procedure the practitioner changes the orientation of the system, as used herein, the term “proximal end” always refers to the end of the system extending from the patient's body (even if the distal end is temporarily closer to the practitioner).

“Fluid” is used in its broadest sense, to refer to any fluid, including both liquids and gases as well as solutions, compounds, suspensions, etc., which generally behave as fluids.

FIGS.1-6illustrate different views of drainage stent delivery systems and related components. In certain views each system may be coupled to, or shown with, additional components not included in every view. Further, in some views only selected components are illustrated, to provide detail into the relationship of the components. Some components may be shown in multiple views, but not discussed in connection with every view. Disclosure provided in connection with any figure is relevant and applicable to disclosure provided in connection with any other figure or embodiment.

FIGS.1-5Bdepict one embodiment of a drainage stent delivery system100. In the illustrated embodiment ofFIG.1, the drainage stent delivery system100is partially composed of a catheter body110, a stent member130, and a coupling member150. The stent member130is configured to facilitate drainage of a cavity of an organ of a patient. For example, the stent member130of the illustrated embodiment can be configured to provide a drainage channel from a patient's kidney to the patient's bladder when the patient's ureter is blocked or restricted.

As further depicted in the embodiment ofFIG.1, the catheter body110includes an elongate tubular member111. A bifurcated hub112is coupled to a proximal end of the tubular member111. The hub112can include a central port113and a side port114. In other embodiments, the hub112may include three, four, or more ports. The central port113is in fluid communication with a lumen of the tubular member111and is configured for passage of an elongate medical instrument (e.g., guidewire) used to insert the drainage stent delivery system100into a patient. Additionally, the central port113can be used to deliver fluid into the patient and/or to drain fluid from the patient (e.g., urine from a kidney and/or bladder). The tubular member111may be formed from any suitable material. For example, the tubular member111can be formed from polymeric materials, including, but not limited to, polyurethane, polyethylene, polypropylene, nylon, etc. In other embodiments, the tubular member111may include a composite wall structure including a polymeric material as previously mentioned and a metal or fiber braid imbedded into the polymeric material. In yet another embodiment, the tubular member111may include an inner layer of a material configured to aid drainage of fluid through the tubular member111and/or increase lubricity of an inner surface of the tubular member111. An outer layer may be of the same material as the inner layer. A length of the tubular member111may range from about 20 cm to about 100 cm, and an outer diameter may range from about 6 Fr to about 16 Fr. Other sizes are also contemplated. In some embodiments, the tubular member111can include a radiopaque agent or radiopaque bands to facilitate visualization and positioning of the tubular member111within the patient.

In the depicted embodiment ofFIG.1, the stent member130includes a tubular body131. The tubular body131may be formed from any suitable material. For example, the tubular body131can be formed from polymeric materials, including, but not limited to, polyurethane, polyethylene, polypropylene, nylon, etc. In other embodiments, the tubular body131may include a composite wall structure including a polymeric material as previously mentioned and a metal or fiber braid imbedded into the polymeric material. In yet another embodiment, the tubular body131may include an inner layer of a material configured to aid drainage of fluid through the tubular body131and/or increase lubricity of an inner surface of the tubular body131. An outer layer may be of the same material as the inner layer. A length of the tubular body131may range from about 20 cm to about 120 cm, and an outer diameter may range from about 6 Fr to about 16 Fr. Other sizes are also contemplated. In some embodiments, the tubular body131can include a radiopaque agent or bands to facilitate visualization and positioning of the tubular body131within the patient.

When the stent member130is in an unrestricted state, as shown inFIG.1, the tubular body131includes a proximal retention member132and a distal retention member133. For example, the retention members132,133may be shaped as loops or pigtails disposed adjacent proximal and distal ends of the tubular body131. In other embodiments, the retention members132,133may be in the form of other expandable features, such as balloons, wings, bulges, etc. In the depicted embodiment, the retention members132,133may be pre-formed, using heat, in the shape of loops or pigtails such that when the guidewire is removed from the stent member130during the insertion procedure, the retention members132,133automatically transition from a straightened state to the unrestricted state shown inFIG.1. In other embodiments, one or more of the retention members132,133may include a shape memory insert (e.g., a metal or metal alloy) configured to transition the retention members132,133from the straightened state to the unrestricted state. In still other embodiments, a tether (e.g., suture) may be releasably coupled to the proximal retention member132and/or the distal retention member133to facilitate transitioning of the proximal retention member132and/or the distal retention member133from the straightened state to the unrestricted state. Additionally, the tether can retain the retention members132,133in the unrestricted state when the stent member130is coupled to the catheter body110. In the depicted embodiment, the stent member130also includes a plurality of drainage ports134disposed adjacent the retention members132,133.

As depicted in the embodiment ofFIG.1, the coupling member150selectively couples a distal end of the catheter body110to a proximal end of the stent member130. As illustrated inFIG.2, the coupling member150includes a first or proximal connector151, a second or distal connector160, and a telescoping connector170. The first connector151, as depicted inFIG.2, includes a body152and a tab153. The body152may be a hollow cylinder and may be formed from shape memory metals or metal alloys, such as nickel titanium alloy, copper aluminum nickel alloy, iron manganese silicon alloy, copper zinc aluminum alloy, etc. The body152may include at least one barb154extending radially outward from the body152. A free-end of the barb154is directed distally such that the barb154can engage with an internal surface of the tubular member111of the catheter body110when the first connector151is disposed within the distal end of the tubular member111. When the barb154is engaged, distal displacement of the first connector151from the tubular member111may be prevented. Optionally and/or alternatively, the body152may additionally include at least one barb155wherein a free-end of the barb155is directed proximally to prevent proximal displacement of the first connector151relative to the tubular member111.

The tab153is shown to extend from a distal end of the first connector151. In the illustrated embodiment, the first connector151includes two tabs153disposed circumferentially 180 degrees from each other. In other embodiments, the first connector151may include a single tab153. In another embodiment, the first connector151may include three, four, five, or more tabs153. The tab153is in a shape of a “T” with a cross portion disposed at a distal end of a longitudinal elongate portion. In other embodiments, the tab153may be of any suitable shape where a distal portion of the tab153is larger than a proximal portion. For example, the distal portion of the tab153may have a circular, oval, elliptical, triangular, square, polygonal, shape, etc. In a natural state, the tab153may be biased radially inward as depicted inFIG.2.

As illustrated inFIG.2, the second connector160includes a body161and a slot or receiver162. The body161may be a hollow cylinder and may be formed from any suitable material such as metallic materials, including, but not limited to, stainless steel, titanium, and shape memory metals or metal alloys, such as nickel titanium alloy, copper aluminum nickel alloy, iron manganese silicon alloy, copper zinc aluminum alloy, etc. The body161may include at least one barb163extending radially outward from the body161. A free-end of the barb163is directed proximally such that the barb163can engage with an internal surface of the tubular body131of the stent member130when the second connector160is disposed within the proximal end of the tubular body131. When the barb163is engaged, proximal displacement of the second connector160from the tubular body131may be prevented. Optionally and/or alternatively, the body161may additionally include at least one barb165wherein a free-end of the barb165is directed distally to prevent distal displacement of the second connector160relative to the tubular member131.

The slot162is shown disposed in a proximal end of the body161. The illustrated embodiment ofFIG.2shows two slots162disposed circumferentially 180 degrees apart. In another embodiment, the second connector160may include a single slot162. In other embodiments, the second connector160may include three, four, five, or more slots162. Stated another way, the number of slots162may equal the number of tabs153of the first connector151, or vice versa. The slot162is shaped and sized to receive the tab153when the first connector151is coupled to the second connector160. For example, in the illustrated embodiment ofFIG.2, the slot162is “T” shaped with a cross portion disposed distally of a longitudinal elongate portion. A sleeve164is shown disposed over the slot162. The sleeve164can prevent the tab153from being displaced radially outward from the slot162when the connectors151,160are coupled together.

The telescoping connector170can be disposed within bores or lumens of the first connector151and the second connector160. The telescoping connector170can be a hollow cylinder made from any suitable material, such as metallic materials, including, but not limited to, stainless steel, titanium, and shape memory metals or metal alloys, such as nickel titanium alloy, copper aluminum nickel alloy, iron manganese silicon alloy, copper zinc aluminum alloy, etc. An outer diameter of the telescoping connector170is smaller than inner diameters of the bores of the first and second connectors151,160to facilitate disposing of the telescoping connector170within the bores when the first and second connectors151,160are coupled together and retraction of the telescoping connector170from the first and second connectors151,160to enable decoupling of the first and second connectors151,160from one another. An elongate cable171is coupled to the telescoping connector170to facilitate retraction of the telescoping connector170from the first and second connectors151,160. Various types of elongate cables171can be used. In some embodiments, the elongate cable171comprises a plurality of strands wound together.

In another embodiment of a drainage stent delivery system100a, as depicted inFIG.6, an elongate cable171amay be configured as an elongate tube circumferentially coupled to a proximal end of a telescoping connector170a. The elongate cable171amay be formed of any suitable material, such as metals or plastics, and can be coupled to the telescoping connector170ausing any suitable method, such as welding, brazing, bonding, etc. When tension is applied to the elongate cable171ato retract the telescoping connector170afrom first and second connectors151a,160a, the elongate cable171ais configured to apply a uniform, circumferential tension force to the telescoping connector170a. This configuration may facilitate a linear displacement of the telescoping connector170afrom the first and second connectors151a,160aand provide a constant diameter through the tubular member111aof the catheter body110a.

The telescoping connector170can be configured to displace the tab153radially outward, as shown inFIG.3A, when the telescoping connector170is disposed through the bore of the first connector151. This displacement allows the tab153to be selectively received by the slot162when the first and second connectors151,160are coupled. As depicted inFIG.3B, when the telescoping connector170is displaced proximally relative to the tab153, the tab153biases radially inward. This biasing allows the tab153to be displaced from the slot162and the first and second connectors151,160to decouple.

FIGS.4A and5Adepict a portion of the drainage stent delivery system100in a coupled configuration, andFIGS.4B and5Bdepict the portion of the drainage stent delivery system100in a decoupled configuration. As shown inFIGS.4A and5A, the first connector151is disposed within the distal end of the tubular member111of the catheter body110. The barb154of the first connector151can be engaging the surface of the lumen of the tubular member111to prevent distal displacement of the first connector151. The tab153is displaced radially outward by the telescoping connector170and received into the slot162of the second connector160. The telescoping connector170is disposed within the bores of the first and second connectors151,160and is displacing the tab153radially outward. The cable171extends proximally from the telescoping connector170. The second connector160is disposed within the proximal end of the lumen of the tubular body131of the stent member130. The barb163can be engaging the inner wall surface of the tubular body131to prevent proximal displacement of the second connector160. The sleeve164is disposed over the slot162to prevent the tab153from being displaced radially outward from the slot162.

When in the coupled configuration, the lumens of the tubular member111and the tubular body131are aligned by the coupling member150. Additionally, rotation of the catheter body110to position the stent member130within the patient's body can cause an equal rotation of the stent member130. In other words, the catheter body110and the stent member130can be rotated at a 1:1 ratio as the drainage stent delivery system100is inserted into the patient's body. For instance, the tab153can engage the slot162to rotate the stent member130as the catheter body110is rotated. When coupled, the stent member130and catheter110can be described as being rotationally fixed.

As shown inFIGS.4B and5B, when the drainage stent delivery system100is in the decoupled configuration, the first connector151is disposed within the distal end of the tubular member111of the catheter body110. The barb154of the first connector151can be engaging the surface of the lumen of the tubular member111to prevent distal displacement of the first connector151. The second connector160is disposed within the proximal end of the lumen of the tubular body131of the stent member130. The barb163is engaging the inner wall surface of the tubular body131to prevent proximal displacement of the second connector160. The telescoping connector170is displaced proximally when tension is applied to the cable171such that the telescoping connector170is not disposed within the second connector160. This allows the tab153to bias radially inward out of the slot162of the second connector160.

The drainage stent delivery system100may be utilized to drain urine from the patient's kidney into the bladder when the patient's ureter is blocked or restricted. In some embodiments, the drainage stent delivery system may be used to drain bile from the patient's liver or gall bladder into the patient's small intestine, where the stent member is disposed within a blocked or restricted bile duct. In other embodiments, the drainage stent delivery system100may be utilized to drain any suitable body cavity, such as the cranial cavity, the pericardial cavity, the pleural cavity, etc.

An exemplary use of a drainage stent delivery system is to drain urine from the patient's kidney into the bladder when the patient's ureter is blocked or restricted. The drainage stent delivery system may be inserted into the patient over a previously inserted guidewire. A distal portion of the stent may be positioned in the bladder and a proximal portion positioned in the kidney. A body of the stent member can be disposed within a blocked or restricted ureter. Positioning of the stent member may require rotation of the stent member. A coupling member that selectively couples the stent member and a catheter body together can facilitate equal rotation of the catheter body and the stent member. The coupling member may include a proximal connector having a tab, a distal connector having a slot to receive the tab, and a telescoping connector removably disposed within the proximal and distal connectors. The telescoping connector can displace the tab radially outward and into the slot. Upon removal of the guidewire, retention members, such as pigtails, of the proximal and distal portions of the stent may form (automatically or manually) to retain the distal portion in the bladder and the proximal portion within the kidney.

A proximal portion of the catheter body can extend outside of the patient's body. A fluid drainage container may be coupled to a hub of the catheter body to collect the urine drained from the kidney and/or bladder. The drainage stent delivery system may remain indwelling for a period of time ranging from about one week to about three weeks. The catheter body may be decoupled from the stent member by proximally retracting the telescoping connector from the first and second connectors. For example, the telescoping connector can be retracted by a proximally directed force applied to a cable coupled to the telescoping connector. Upon retraction of the telescoping connector, the tab is biased radially inward and displaced from the slot. The catheter body is separated from the stent member and the catheter body is removed from the patient, leaving the stent member in place.

References to approximations are made throughout this specification, such as by use of the term “substantially.” For each such reference, it is to be understood that, in some embodiments, the value, feature, or characteristic may be specified without approximation. For example, where qualifiers such as “about” and “substantially” are used, these terms include within their scope the qualified words in the absence of their qualifiers. For example, where the term “substantially perpendicular” is recited with respect to a feature, it is understood that in further embodiments, the feature can have a precisely perpendicular configuration.

The claims following this written disclosure are hereby expressly incorporated into the present written disclosure, with each claim standing on its own as a separate embodiment. This disclosure includes all permutations of the independent claims with their dependent claims. Moreover, additional embodiments capable of derivation from the independent and dependent claims that follow are also expressly incorporated into the present written description.

Without further elaboration, it is believed that one skilled in the art can use the preceding description to utilize the invention to its fullest extent. The claims and embodiments disclosed herein are to be construed as merely illustrative and exemplary, and not a limitation of the scope of the present disclosure in any way. It will be apparent to those having ordinary skill in the art, with the aid of the present disclosure, that changes may be made to the details of the above-described embodiments without departing from the underlying principles of the disclosure herein. In other words, various modifications and improvements of the embodiments specifically disclosed in the description above are within the scope of the appended claims. Moreover, the order of the steps or actions of the methods disclosed herein may be changed by those skilled in the art without departing from the scope of the present disclosure. In other words, unless a specific order of steps or actions is required for proper operation of the embodiment, the order or use of specific steps or actions may be modified. The scope of the invention is therefore defined by the following claims and their equivalents.