JP7650866B2 - Barbed microcatheter having a fluid exit opening for injecting therapeutic fluid into tissue and methods of making and using same - Patents.com - Google Patents

Description

CROSS-REFERENCE TO RELATED APPLICATIONS
This application claims priority to U.S. Patent Application No. 16/570,017, filed September 13, 2019, and U.S. Patent Application No. 16/570,028, filed September 13, 2019.

FIELD OF THEINVENTION
This patent application relates generally to medical devices, and more specifically to catheters that are implanted in patients and methods of making the same.

Many medical treatment protocols involve injecting therapeutic fluids into selected areas of a patient's body. Types of therapeutic fluids typically used by physicians to treat patients include anesthetics, antibiotics, antimicrobial agents, chemotherapeutic agents, and growth factors.

Historically, therapeutic fluids are delivered to patients using catheters that are temporarily implanted in the patient to deliver the therapeutic fluid for the duration of the treatment period. At the end of the treatment period, the catheter is removed from the patient. Unfortunately, catheter removal often results in wound breakdown and pain for the patient.

Linear catheters are often used to treat patients. Linear catheters are typically held in place using sutures or other fixation devices (e.g., staples), which can complicate the procedure, introduce additional foreign material into the patient, and impair the performance of the catheter by impeding the flow of therapeutic fluids through the catheter.

In some cases, rather than using linear catheters, it is necessary to use nonlinear catheters that are placed in complex three-dimensional configurations inside a patient. For example, nonlinear catheters with three-dimensional configurations can be used to extend around objects located inside the body, such as tumors, artificial joints, or complex surgical wounds. Due to their nonlinear shapes, medical personnel often have difficulty removing the nonlinear catheters from the patient.

Catheters that are implanted in patients come in many different sizes. In some cases, medical personnel must use fine catheters, also called microcatheters, to deliver therapeutic fluids to patients. Forming fluid passages within fine catheters can be very difficult due to the precise tolerances required to maintain uniform fluid flow over the length of the fine catheter.

When forming fluid passageways in larger sized catheters, sharpened hollow stainless steel tubing can be used to core material from the catheter wall. This approach becomes more difficult as catheter size decreases because there is a limit to the size of sharpened hollow stainless steel tubing that can be used to form fluid passageways in the catheter. Even when exceptionally fine steel tubing can be procured to form the fluid passageways, the material that is cored from the catheter wall to form the fluid passageways tends to become lodged within the catheter lumen and must be removed from the lumen. Removing the punched material is not without its challenges.

Fluid passages can be formed in the catheter tube using a laser to form the passage. However, because it is difficult to precisely control the power level of the laser, the fluid passages created by the laser are often drilled completely through the catheter tube as opposed to remaining on only one side of the catheter tube. The laser also vaporizes and removes material, which can recondense on or within the catheter tube. Furthermore, the chemical structure of the removed/vaporized material is often altered by the intense heat of the laser, such that the laser-drilled catheter is no longer biocompatible or easily quantifiable for medical device design control and regulatory registration purposes. In addition, the laser tends to locally heat the thermal material, changing the structure and molecular orientation of the catheter tube material, resulting in a catheter with inferior mechanical properties. Finally, lasers providing sufficient power and spot sizes less than 30 μm can be very expensive, increasing manufacturing costs.

In view of the above deficiencies, there remains a need for systems, devices, and methods for safely, effectively, economically, and reliably mass-producing microcatheters having fluid exit openings.

There remains a need for systems, devices, and methods for manufacturing microcatheters having fluid exit openings of different sizes along the length of the microcatheter to achieve uniform fluid delivery.

Furthermore, there remains a need for microcatheters having fluid exit openings of different sizes, including smaller fluid exit openings located closer to the fluid source and larger fluid exit openings located further away from the fluid source.

Additionally, there remains a need for systems, devices, and methods for fabricating microcatheters with fluid exit openings without altering the molecular structure, properties, and/or chemistry of the materials used to fabricate the microcatheters.

Additionally, there remains a need for automated systems and methods for safely, effectively, economically, and reliably mass-producing microcatheters having fine fluid exit openings for localized delivery of therapeutic fluids to a patient.

There also remains a need for an absorbent barbed microcatheter having a fluid exit opening for delivering therapeutic fluid to a patient, whereby the microcatheter is absorbed by the patient's body and does not need to be removed from the patient.

In one embodiment, the microcatheter having a fluid exit opening for delivering therapeutic fluid to the patient is made from a bioabsorbable material, thereby eliminating the need for catheter removal at the end of the treatment period.

In one embodiment, a microcatheter having a fluid exit opening for delivering a therapeutic fluid incorporates a continuous fixation method, such as a barb, that allows a medical professional (e.g., a surgeon) to precisely position the microcatheter within a patient without the need for additional fixation mechanisms, such as sutures or staples. Such catheters (e.g., barbed microcatheters) can be readily positioned preoperatively in any desired configuration with relative ease and minimal additional procedural time.

In one embodiment, the microcatheter having a fluid exit opening for delivering a therapeutic fluid preferably includes an elongated central lumen extending along the length of the catheter. The microcatheter preferably includes a punched or cut fixation barb for holding the catheter in place inside the patient.

In one embodiment, a barbed microcatheter for delivering a fluid to a patient preferably comprises a hollow tube having a proximal end, a distal end, and an elongated lumen extending between the proximal and distal ends of the hollow tube, barbs projecting outwardly from the hollow tube, and a plurality of fluid exit openings formed in the hollow tube that are in fluid communication with the elongated lumen of the hollow tube.

In one embodiment, the fluid outlet openings are spaced apart from one another between the proximal and distal ends of the hollow tube.

In one embodiment, the fluid outlet openings may be evenly spaced apart from one another between the proximal and distal ends of the hollow tube.

In one embodiment, each of the fluid outlet openings may be the same size.

In one embodiment, two or more of the fluid outlet openings may have different sizes. In one embodiment, the size of the fluid outlet openings may gradually increase in size between an end of the hollow tube closer to the fluid source and an end of the hollow tube further away from the fluid source.

In one embodiment, the fluid exit opening is a round hole.

In one embodiment, the fluid exit opening is an elongated slit. In one embodiment, the hollow tube has a longitudinal axis extending between the proximal and distal ends of the hollow tube, and the elongated slit has a length extending along a common axis parallel to the longitudinal axis of the hollow tube.

In one embodiment, the hollow tube preferably has an outer surface and an inner surface surrounding the elongated lumen. In one embodiment, a fluid outlet opening is formed in the hollow tube and extends from the outer surface of the hollow tube to the inner surface of the hollow tube and is in fluid communication with the elongated lumen.

In one embodiment, the inner surface of the hollow tube preferably defines an inner cross-sectional diameter of the hollow tube, and the outer surface of the cylindrical wall preferably defines an outer cross-sectional diameter of the hollow tube that is preferably about two times larger than the inner cross-sectional diameter of the hollow tube.

In one embodiment, the hollow tube has a wall thickness of about 0.125 mm, the outer cross-sectional diameter of the hollow tube is about 0.50 mm, and the inner cross-sectional diameter of the hollow tube is about 0.25 mm.

In one embodiment, the barbed microcatheter is desirably made of an absorbable biocompatible polymer such that the barbed microcatheter is absorbed and does not need to be removed from the patient at the end of the treatment period.

In one embodiment, a barbed microcatheter for delivering fluid to tissue preferably comprises a hollow tube having a proximal end, a distal end, and an elongated lumen disposed within the hollow tube extending between the proximal and distal ends of the hollow tube, barbs projecting outwardly from an outer surface of the hollow tube, and a plurality of fluid exit openings formed in the outer surface of the hollow tube in fluid communication with the elongated lumen of the hollow tube. In one embodiment, the fluid exit openings are evenly spaced from one another between the proximal and distal ends of the hollow tube.

In one embodiment, each of the fluid exit openings has the same size. In one embodiment, two or more of the fluid exit openings have different sizes. In one embodiment, the fluid exit openings have a shape selected from the group consisting of a round hole and an elongated slit.

In one embodiment, the elongated lumen of the hollow tube defines a cross-sectional diameter of about 0.25 mm and the exterior surface of the hollow tube defines a cross-sectional diameter of about 0.50 mm.

In one embodiment, the anchor is secured to the proximal end of the hollow tube.

In one embodiment, a surgical needle, such as a curved needle, is secured to the distal end of the hollow tube.

In one embodiment, a barbed microcatheter for delivering a therapeutic fluid to a tissue preferably comprises a hollow tube having a proximal end, a distal end, and an elongated lumen disposed within the hollow tube extending between the proximal and distal ends of the hollow tube, a plurality of barbs projecting outwardly from an outer surface of the hollow tube, and a plurality of fluid exit openings formed on the outer surface of the hollow tube in fluid communication with the elongated lumen of the hollow tube, the plurality of fluid exit openings being evenly spaced from one another between the proximal and distal ends of the hollow tube.

In one embodiment, the barbed microcatheter preferably comprises an anchor secured to the proximal end of the hollow tube and a surgical needle secured to the distal end of the hollow tube.

In one embodiment, the barbed microcatheter preferably includes two or more fluid exit openings having different sizes, including a first fluid exit opening located adjacent to the anchor having a first size, and a second fluid exit opening located adjacent to the surgical needle having a second size smaller than the first size of the first fluid exit opening.

Infections associated with orthopedic implants can be devastating for patients and often result in serious consequences including reoperation, amputation, or death. Delivery of local antibiotics to the infected site in large doses, which are harmful when delivered systemically but safe when delivered locally, can be achieved using the microcatheters disclosed herein.

Inoperable tumors often leave patients with limited options. Delivery of high-dose chemotherapeutic agents or immunotherapy (i.e., engineered T cells) directly to the tumor may provide unprecedented benefits. The bioabsorbable microcatheters disclosed herein may be used to provide localized delivery of this type of therapeutic fluid.

Post-operative pain management with opioids is often not ideal for several reasons, including the risk of addiction, severe constipation, and cognitive impairment. Delivery of local anesthetic directly to the wound site using the microcatheters disclosed herein preferably provides a mechanism for reducing opioid usage while minimizing patient pain and suffering.

In one embodiment, the barbed microcatheter can be coated and/or impregnated with an antimicrobial agent to prevent bacterial colonization. In one embodiment, the preferred antimicrobial agent is triclosan. In one embodiment, a steam process can be used to apply the triclosan antimicrobial agent to the barbed microcatheter, such as a polymeric barbed microcatheter made of polydioxanone or polycaprolactone. In one embodiment, the antimicrobial agent used in the barbed microcatheter can include, but is not limited to, triclosan, chlorhexidine, povidone-iodine, and/or silver compounds.

In one embodiment, a method for making a barbed microcatheter includes forming a microcatheter blank (e.g., a polymer tube), preferably simultaneously with forming a fluid exit opening (e.g., a fluid discharge passage), or alternatively, as a first prerequisite step to forming a fluid exit opening. In one embodiment, the microcatheter blank may be formed and consolidated by methods well known in the art of polymer extrusion and polymer drawing. In one embodiment, the microcatheter blank may be flattened to various degrees to produce lateral flattened regions that may be used to form barbs that protrude from the hollow tube.

In one embodiment, the sides of the microcatheter blank may be flattened and the flattened sides sealed using thermal or ultrasonic energy. The cross-sectional shape of the microcatheter blank with the flattened sides may be heat set before or during the barb forming step to produce a microcatheter with an elliptical cross-section. In one embodiment, the microcatheter blank may be shielded from the heat and returned to a predominantly circular cross-section after barb forming.

In one embodiment, the fluid exit openings may be formed simultaneously with any of the manufacturing steps disclosed herein, or may be accomplished in one or more separate steps as described herein.

In one embodiment, the barbed microcatheters disclosed herein preferably allow for controlled and equal distribution of therapeutic fluid from fluid exit openings (e.g., holes, slits) located along the length of the hollow tube of the barbed microcatheter. In one embodiment, the fluid exit openings/slits are formed on the upper side of the hollow tube of the barbed microcatheter. In one embodiment, the lower side of the hollow tube does not have a fluid exit opening/slit.

In one embodiment, the cross-sectional area of the fluid exit openings may increase in size in relation to increasing distance from the fluid source. In one embodiment, fluid exit openings closer to the fluid source may be smaller and fluid exit openings further away from the fluid source may be larger. The size of the fluid exit openings may increase gradually along the length of the barbed microcatheter.

In one embodiment, the fluid exit opening formed in the hollow tube of the barbed microcatheter may include an elongated slit. In one embodiment, the elongated slit may be substantially closed at a lower fluid pressure level (e.g., zero fluid pressure), but the elongated slit preferably opens when exposed to a higher fluid pressure level, which may be generated by a syringe or fluid pump. Using an elongated slit that opens when exposed to a higher pressure level, preferably, the entire length of the microcatheter may be initially filled with therapeutic fluid at a lower fluid pressure level. Thereafter, when the higher fluid pressure level is achieved, the elongated fluid exit slit opens to release therapeutic fluid from the elongated fluid exit slit.

In one embodiment, the barbed microcatheter may have an anchor fixed at one end and a needle (e.g., a curved needle) fixed at the opposite end. In one embodiment, the anchor is fixed at the proximal or rear end of the barbed microcatheter and the needle is fixed at the distal or front end of the barbed microcatheter. In one embodiment, a fixation device such as a loop or reverse barb may be used. In one embodiment, a symmetrical catheter with double arms and looped barbs may also be produced.

In one embodiment, the barbed microcatheter may have fluid exit openings/holes that are the same size. In one embodiment, the barbed microcatheter may have fluid exit openings/holes that are various sizes.

In one embodiment, the barbed microcatheter may have fluid exit slits that have the same length. In one embodiment, the barbed microcatheter may have fluid exit slits that have various lengths.

In one embodiment, needles are used to form fluid exit openings in the hollow tube of the barbed microcatheter. In one embodiment, the diameter of each needle can vary along the length of the microcatheter to vary the diameter of each fluid exit opening.

In one embodiment, the forming die may be configured to include a barbed microcatheter after the initial forming step and to hold the barbed microcatheter in a set position during a punching operation to form one or more fluid exit openings. In one embodiment, the fluid exit opening die may be used to simultaneously form the barbed microcatheter while punching the fluid exit openings.

In one embodiment, the forming die preferably has embedded piercing needles located along the length of the barbed microcatheter contained within the forming die. The insertion depth of each piercing needle may be varied along the length of the forming die to control the size (i.e., diameter) of the fluid exit opening. In one embodiment, the deeper the taper point of the needle is inserted into the die, the larger the size of the fluid exit opening formed in the hollow tube of the barbed microcatheter.

In one embodiment, the piercing needles may be made to move into the die cavity after the microcatheter (or microcatheter blank) is inserted into the die, rather than being permanently attached to the die. In one embodiment, the needles used to form the fluid exit openings may all articulate together to enter and exit the die cavity, or may be made to enter and exit the die individually.

In one embodiment, the systems, devices, and methods for making a barbed microcatheter may include using one or more cutting blades to cut slits into the hollow tube to form the fluid exit slits. In one embodiment, the cutting blades may be attached to at least half of the die or may be made to slide into and out of the die cavity simultaneously or individually. In one embodiment, the depth to which the cutting blades are inserted into the die may be controlled to create elongated slits of various lengths. Making elongated slits in the hollow tube of the microcatheter has minimal effect on the tensile strength of the microcatheter. In one embodiment, the elongated slits preferably provide a mechanism for controlling fluid flow rate, whereby the slits close at low fluid pressure levels and open at incrementally higher fluid pressure levels to release the fluid.

In one embodiment, a system, device, and method for forming an elongated slit in a hollow tube of a microcatheter may include inserting a cutting edge of a cutting blade into an outer wall of the hollow tube of the microcatheter and moving the cutting edge relative to the hollow tube to form an elongated slit in the hollow tube. The cutting blade may articulate in two axes, or the cutting blade may be configured to move up and down while a die holding the microcatheter translates horizontally relative to the cutting blade.

In one embodiment, one or more cutting blades can be used to form barbs on the sides of the microcatheter. In one embodiment, cutting blades can be used to form barbs that extend longitudinally, orthogonally, or at any angle between the longitudinal and orthogonal orientations. Crosses or "x-patterns" can also be created through multiple passes of the cutting blade or the use of specially shaped cutting blades.

In other embodiments, a laser and/or electron beam may be used to form the barbs of a barbed microcatheter.

In one embodiment, a method of making a barbed microcatheter having a fluid exit opening preferably includes compressing a first lateral side and a second lateral side of a polymer blank to form a barbed microcatheter blank, the barbed microcatheter blank including a first flattened region extending along the first lateral side of the barbed microcatheter blank, a second flattened region extending along the second lateral side of the barbed microcatheter blank, and a hollow tube having an elongated lumen located between the first flattened region and the second flattened region.

In one embodiment, a method of making a barbed microcatheter having a fluid exit opening may include removing material from a first flattened region and a second flattened region of a barbed microcatheter blank to form barbs that project outwardly from opposite sides of a hollow tube.

In one embodiment, a method of making a barbed microcatheter having a fluid exit opening may include forming a fluid exit opening in a wall of a hollow tube that is in fluid communication with an elongated lumen of the hollow tube.

In one embodiment, a method of making a barbed microcatheter having a fluid exit opening may include compressing a proximal end of a polymer blank to form a tissue anchor connected to the proximal end of a hollow tube and securing a needle to the distal end of the hollow tube.

In one embodiment, at least one cutting element is used to form a fluid exit opening in the wall of the hollow tube.

In one embodiment, the step of forming the fluid outlet opening may include forming a first fluid outlet opening in the wall of the hollow tube having a first size, and forming a second fluid outlet opening in the wall of the hollow tube having a second size that is larger than the first size of the first fluid outlet opening.

In one embodiment, the step of forming the fluid outlet openings may include forming a series of progressively larger fluid outlet openings in the wall of the hollow tube.

In one embodiment, the fluid outlet opening may be formed simultaneously during the step of forming the fluid outlet opening.

In one embodiment, the fluid outlet openings are formed at different times, independent of each other, during the step of forming the fluid outlet openings.

In one embodiment, the tissue anchor connected to the proximal end of the hollow tube preferably includes a flat tab having a length and a width.

In one embodiment, the step of compressing the first and second lateral sides of the polymer blank may include placing the polymer blank in a press die having an upper press die portion above the polymer blank and a lower press die portion opposite the upper press die portion and below the polymer blank. In one embodiment, the press die is preferably moved to a closed position for compressing the upper and lower surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened regions and the hollow tube.

In one embodiment, the upper press die portion preferably includes a plurality of cutting elements protruding from an underside of the upper press die portion. In one embodiment, when the press die is in a closed position, the cutting elements engage the hollow tube to form a fluid exit opening in the hollow tube.

In one embodiment, the step of removing material preferably includes cutting the first and second flattened regions of the barbed microcatheter blank to form barbs that project outwardly from opposite sides of the hollow tube.

In one embodiment, the cutting step may include placing the barbed microcatheter blank, including the first and second flattened regions and the hollow tube, in a cutting die, the cutting die having an upper cutting die portion and a lower cutting die portion opposite the upper cutting die portion, and moving the cutting die to a closed position to cut the first and second flattened regions of the barbed microcatheter blank to form barbs projecting outwardly from respective opposite sides of the hollow tube.

In one embodiment, the upper cutting die portion preferably includes a plurality of cutting elements protruding from an underside of the upper cutting die portion. In one embodiment, when the cutting die is in a closed position, the cutting elements engage the hollow tube to form a fluid exit opening in the hollow tube.

In one embodiment, press rollers can be used on the polymer blank to compress the top and bottom surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened regions of the barbed microcatheter blank and a hollow tube.

In one embodiment, a method of making a barbed microcatheter having a fluid exit opening desirably includes obtaining a barbed microcatheter blank, the barbed microcatheter blank including a hollow tube having a proximal end, a distal end, and an elongated lumen extending between the proximal and distal ends of the hollow tube, and first and second flattened regions extending along respective opposite sides of the hollow tube.

In one embodiment, a method of making a barbed microcatheter may include removing material from a first flattened region and a second flattened region of a barbed microcatheter blank to form barbs that protrude outwardly from opposite sides of a hollow tube, using one or more cutting elements to form a fluid exit opening in a wall of the hollow tube that is in fluid communication with an elongated lumen of the hollow tube, forming a tissue anchor connected to a proximal end of the hollow tube, and securing a surgical needle to a distal end of the hollow tube.

In one embodiment, a method of delivering a therapeutic fluid to tissue preferably includes positioning a barbed microcatheter adjacent to a wound having a first wound end and a second wound end, the barbed microcatheter may include a hollow tube having an elongated lumen extending between the first and second ends of the hollow tube, barbs projecting outwardly from opposite sides of the hollow tube, a fluid exit opening formed in the hollow tube in fluid communication with the elongated lumen, a tissue anchor secured to the first end of the hollow tube, and a needle secured to the second end of the hollow tube.

In one embodiment, a method of delivering therapeutic fluid to tissue may include using a needle to form a first tissue opening at a first end of the wound and pulling a hollow tube completely through the first tissue opening until a tissue anchor abuts the tissue at the first end of the wound.

In one embodiment, a method of delivering therapeutic fluid to tissue may include using a needle to form a second tissue opening at a second end of the wound and pulling the hollow tube completely through the second tissue opening such that barbs projecting outwardly from opposite sides of the hollow tube engage tissue within the wound located between the first and second ends of the wound.

In one embodiment, the method of delivering therapeutic fluid to tissue preferably includes passing a needle through a skin layer of a patient such that the needle and the second end of the hollow tube are located outside the patient.

In one embodiment, a method of delivering therapeutic fluid to tissue may include cutting the second end of the hollow tube to remove the needle from the hollow tube, and introducing therapeutic fluid into the cut second end of the hollow tube such that the therapeutic fluid flows into the elongated lumen and through the fluid exit opening to infuse the therapeutic fluid into the wound.

In one embodiment, after the needle passes through the skin layer to be positioned outside the patient, the intermediate section of the hollow tube, including the barb and the fluid exit opening, is preferably positioned between the first end and the second end of the wound.

In one embodiment, after the barbed microcatheter is positioned within the wound, the midsection of the hollow tube is placed within the closed wound.

In one embodiment, after the barbed microcatheter is positioned within the wound, the intermediate section of the hollow tube extends along a straight path between the first and second ends of the wound.

In one embodiment, after the barbed microcatheter is positioned within the wound, the intermediate section of the hollow tube extends along a nonlinear path between the first and second ends of the wound.

These and other preferred embodiments of the present invention are described in more detail below.

FIG. 1 is a top view of a barbed microcatheter having a fluid exit opening, according to an embodiment of the present patent application. FIG. 1 is a perspective view of a barbed microcatheter having a fluid exit opening, according to one embodiment of the present patent application. FIG. 2B is a top view of the barbed microcatheter shown in FIG. 2A. FIG. 2C is a bottom view of the barbed microcatheter shown in FIGS. 2A-B. FIG. 2C is a view of the proximal end of the barbed microcatheter shown in FIGS. 2A-2C. FIG. 2C is a left side view of the barbed microcatheter shown in FIGS. 2A-2D. FIG. 2C is a cross-sectional view of the barbed microcatheter shown in FIGS. 2A-2E. FIG. 1 is a perspective view of a microcatheter blank used to form a barbed microcatheter having a fluid exit opening, according to one embodiment of the present patent application. FIG. 4B is a cross-sectional view of the microcatheter blank shown in FIG. FIG. 1 is a perspective view of a pressing die used to form a microcatheter blank having flattened lateral regions extending along the length of the microcatheter blank in accordance with one embodiment of the present patent application. FIG. 1 is a perspective view of a microcatheter blank having flattened lateral regions extending along the length of the microcatheter blank in accordance with one embodiment of the present patent application. FIG. 1 is a perspective view of a press roller used to form a microcatheter blank having flattened lateral regions extending along the length of the microcatheter blank, according to one embodiment of the present patent application. FIG. 1 is a perspective view of a cutting die used to cut barbs into the flattened lateral regions extending along the length of a microcatheter blank according to one embodiment of the present patent application. FIG. 9 is a perspective view of the microcatheter blank shown in FIG. FIG. 10 is a perspective view of a needle used to form a fluid exit opening in the microcatheter blank of FIG. 9 according to an embodiment of the present patent application. FIG. 10B is a close-up view of the distal end of the needle shown in FIG. 10A. FIG. 2 is a perspective view of a die used to form a barbed microcatheter having a fluid exit opening according to one embodiment of the present patent application. FIG. 1 is a top view of a barbed microcatheter having a fluid exit opening formed on the upper side of a hollow tube, according to an embodiment of the present patent application. FIG. 1 is a top view of a barbed microcatheter having a hollow tube with spaced apart fluid exit openings having different sizes, according to an embodiment of the present patent application. FIG. 1 is a perspective view of a die used to form spaced apart fluid exit openings in a hollow tube of a barbed microcatheter according to one embodiment of the present patent application. FIG. 14B is a side view of the die shown in FIG. 14A. FIG. 1 is a perspective view of a die used to form spaced apart fluid exit openings in a hollow tube of a barbed microcatheter according to one embodiment of the present patent application. FIG. 15B is a side view of the die shown in FIG. 15A. FIG. 1 is a top view of a barbed microcatheter having spaced fluid exit openings, according to one embodiment of the present patent application. FIG. 1 is a perspective view of a barbed microcatheter having spaced exit slits in accordance with one embodiment of the present patent application. FIG. 17B is a top view of the barbed microcatheter shown in FIG. 17A. FIG. 17C is a bottom view of the barbed microcatheter shown in FIGS. 17A-B. FIG. 17B is a view of the proximal end of the barbed microcatheter shown in FIGS. 17A-17C. FIG. 17B is a left side view of the barbed microcatheter shown in FIGS. 17A-17D. FIG. 17B is a cross-sectional view of the barbed microcatheter shown in FIGS. 17A-17E. FIG. 1 is a perspective view of a die used to form spaced apart fluid exit slits in the upper surface of a hollow tube of a barbed microcatheter according to one embodiment of the present patent application. FIG. 1 is a perspective view of a cutting blade used to form a fluid exit slit in a hollow tube of a barbed microcatheter, according to an embodiment of the present patent application. FIG. 20B is an enlarged view of the distal end of the cutting blade shown in FIG. 20A. 1 illustrates a first step in a method for forming a fluid exit slit in a hollow tube of a barbed microcatheter, according to one embodiment of the present patent application. 1 illustrates a second stage of a method for forming a fluid exit slit in a hollow tube of a barbed microcatheter, according to an embodiment of the present patent application. 13 illustrates a third step in a method for forming a fluid exit slit in a hollow tube of a barbed microcatheter, according to an embodiment of the present patent application. 13 illustrates a fourth step in a method for forming a fluid exit slit in a hollow tube of a barbed microcatheter, according to an embodiment of the present patent application. FIG. 1 is a perspective view of the top surface of a die used to form a fluid exit slit in a hollow body of a barbed microcatheter according to an embodiment of the present patent application. FIG. 25B is another perspective side view of the die shown in FIG. 25A. 25A and 25B are diagrams illustrating steps in a method for forming spaced apart fluid exit slits in a hollow tube of a barbed microcatheter, according to one embodiment of the present patent application. FIG. 25D is a side view of the die shown in FIG. 25C. FIG. 1 is a top view of a barbed microcatheter including a hollow tube having spaced apart fluid exit slits formed in an upper side of the hollow tube, according to an embodiment of the present patent application. 1 illustrates a first step in a method of using a barbed microcatheter to inject therapeutic fluid into a wound, according to one embodiment of the present patent application. 1 illustrates a second step in a method of using a barbed microcatheter to inject therapeutic fluid into a wound, according to one embodiment of the present patent application. 13 illustrates a third step in a method of using a barbed microcatheter to inject therapeutic fluid into a wound, according to one embodiment of the present patent application. 1 illustrates a first step in a method of using a barbed microcatheter having a non-linear configuration to inject therapeutic fluid into a wound, according to one embodiment of the present patent application. 1 illustrates a second step in a method of using a barbed microcatheter having a non-linear configuration to inject therapeutic fluid into a wound, according to an embodiment of the present patent application. 13 illustrates a third step in a method of using a barbed microcatheter having a non-linear configuration to inject therapeutic fluid into a wound, according to an embodiment of the present patent application.

1, in one embodiment, the barbed microcatheter 100 preferably comprises a hollow tube 102 having a proximal end 104 and a distal end 106. In one embodiment, the barbed microcatheter 100 preferably has a length _L1 of about 2-12 inches, more preferably about 7-8 inches. The barbed microcatheter 100 desirably comprises barbs 108 spaced apart along the length of the hollow tube 102 and projecting from opposite sides of the hollow tube. In one embodiment, the barbed microcatheter comprises a plurality of fluid exit openings 110 formed in the outer wall of the hollow tube 102 and spaced apart along the length of the hollow tube. In one embodiment, the hollow tube 102 has an elongated lumen extending along the length of the hollow tube. The fluid exit openings 110 are preferably in fluid communication with the elongated lumen such that fluid flowing through the elongated lumen of the hollow tube may exit the hollow tube via the fluid exit openings. In one embodiment, the barbed microcatheter 100 may include a tissue anchor 112 secured to the proximal end 104 of the hollow tube 102 and a surgical needle 114 secured to the distal end 106 of the hollow tube 102 .

2A-2E, in one embodiment, the barbed microcatheter 100 preferably includes a hollow tube 102 with fluid exit openings 110 formed in an outer wall 116 of the hollow tube 102. In one embodiment, the fluid exit openings 110 are preferably spaced apart from one another along the length of the hollow tube 102. In one embodiment, the fluid exit openings 110 are round holes. In one embodiment, the outer wall 116 of the hollow tube 102 has an outer surface 118 and an inner surface 120 that surrounds an elongated lumen 122 of the hollow tube 102. The elongated lumen preferably extends along the length of the hollow tube and is in fluid communication with the spaced apart fluid exit openings such that fluid (e.g., a therapeutic fluid) may be dispensed from the barbed microcatheter.

In one embodiment, the barbed microcatheter 100 preferably comprises a plurality of barbs 108 extending from the side of the hollow tube 102. The barbs 108 are preferably spaced apart from one another along the length of the hollow tube 102. In one embodiment, the barbs 108 may be symmetrically arranged in pairs of barbs that are spaced apart from one another along the length of the hollow tube, such that each pair of barbs extend apart from one another on respective opposite sides of the hollow tube 102.

2B, in one embodiment, the fluid exit openings 110 (e.g., round holes having a diameter) are spaced apart from one another along the length of the hollow tube 102 of the barbed microcatheter 100. In one embodiment, the distance _D1 between adjacent spaced apart fluid exit openings 110 may be about 4-25 millimeters, more preferably about 4-12 millimeters. In one embodiment, the spaced apart fluid exit openings 110 may be the same size (i.e., the same diameter). In one embodiment, the spaced apart fluid exit openings 110 may have different sizes (i.e., different diameters).

2B and 2C, in one embodiment, the fluid exit opening 110 is desirably formed on the upper side of the hollow tube 102 of the barbed microcatheter 100. In one embodiment, the fluid exit opening is formed on the upper side of the hollow tube, and no opening is formed on the lower side of the hollow tube. FIG. 2C shows the underside of the hollow tube 102 of the barbed microcatheter without a fluid exit opening.

2D, in one embodiment, the hollow tube 102 of the barbed microcatheter 100 preferably includes an outer wall 116 having an outer surface 118 and an inner surface 120 surrounding an elongated lumen 122. In one embodiment, the fluid exit opening 110 is formed on the upper side of the outer wall 116 of the hollow tube 102. In one embodiment, the fluid exit opening 110 is desirably in fluid communication with the elongated lumen 122 extending along the length of the hollow tube such that fluid within the elongated lumen can be distributed through the fluid exit opening 110.

In one embodiment, the outer surface 118 of the outer wall 116 of the hollow tube 102 defines an outer diameter OD ₁ of approximately 0.5 millimeters. In one embodiment, the inner surface 120 of the outer wall 116 of the hollow tube 102 defines an inner diameter ID ₁ of approximately 0.25 millimeters. In one embodiment, the outer diameter OD ₁ defined by the outer wall of the hollow tube is approximately two times greater than the inner diameter ID ₁ defined by the inner surface of the outer wall of the hollow tube. In one embodiment, the outer wall 116 of the hollow tube preferably has a thickness T ₁ of approximately 0.125 millimeters.

2A-2E, in one embodiment, the barbed microcatheter 100 preferably includes barbs 108 protruding from opposite sides of the hollow tube 102. The barbs are preferably spaced apart from one another on each side of the hollow tube. In one embodiment, the barbs have a thickness _T2 that is at least 10% of the size of the outer diameter _OD1 of the hollow tube 102. In one embodiment, the thickness _T2 of the barbs 108 may be between about 0.05 and 0.20 millimeters. In one embodiment, the pair of barbs 108 may define a tip-to-tip width _W1 of between about 1 and 3 mm.

Referring to FIG. 3, in one embodiment, the barbed microcatheter 100 (FIGS. 2A-2E) comprises a hollow tube 102 having an outer wall 116, preferably comprising an outer surface 118 and an inner surface 120 surrounding an elongated lumen 122 extending along the length of the hollow tube 102. The barbed microcatheter 100 preferably comprises fluid exit openings 110 spaced apart from one another along the length of the hollow tube 102. In one embodiment, the fluid exit openings 110 are formed on an upper side 124 of the hollow tube 102. In one embodiment, the hollow tube 102 has a lower surface 126 that is devoid of any fluid exit openings provided on the upper side 124.

In one embodiment, the fluid exit opening 110 penetrates completely through the thickness _T1 of the outer wall 116 of the hollow tube 102, thereby fluidly communicating with the elongated lumen 122 extending along the length of the hollow tube. In one embodiment, the barbed microcatheter 100 can be implanted in tissue and a fluid, such as a therapeutic fluid, can be introduced into the elongated lumen 122 of the hollow tube 102, whereupon the fluid passes through the fluid exit opening 110 to bathe the tissue surrounding the hollow tube. In one embodiment, the barbed microcatheter 100 preferably includes barbs 108 spaced apart from one another along the length of the hollow tube 102. In one embodiment, after the barbed microcatheter 100 is implanted in tissue, the barbs 108 protruding from the sides of the hollow tube 102 preferably engage the surrounding tissue to hold the hollow tube in place within the tissue.

In one embodiment, the barbed microcatheter having a fluid exit opening is preferably made from an absorbable biocompatible polymeric material. The absorbable polymer may include conventional biocompatible polymers such as lactide, polylactic acid, polyglycolic acid, glycolide, polydioxanone, polycaprolactone, copolymers thereof, and blends thereof.

In one embodiment, the barbed microcatheter can be coated and/or impregnated with an antimicrobial agent to prevent bacterial colonization. In one embodiment, the preferred antimicrobial agent is triclosan. In one embodiment, a steam process can be used to apply the triclosan antimicrobial agent to the barbed microcatheter, such as a polymeric barbed microcatheter made of polydioxanone or polycaprolactone. In one embodiment, the antimicrobial agent used in the barbed microcatheter can include, but is not limited to, triclosan, chlorhexidine, povidone-iodine, and/or silver compounds.

4A and 4B, in one embodiment, the barbed microcatheter 100 shown in FIGS. 1-3 and described above may be made by first forming a microcatheter blank 128 having an outer wall 130 with an outer surface 132, an inner surface 134, and an elongated lumen 136 extending along the length of the microcatheter blank 128. As used herein, the term blank refers to an object (e.g., a hollow tube precursor) intended for further shaping or finishing to create a final product (e.g., a barbed microcatheter with a fluid exit opening). The microcatheter blank may be stretched to control the molecular orientation of the grains of the microcatheter blank, which preferably improves the strength of the microcatheter blank. As described in more detail herein, the microcatheter blank 128 may be subjected to additional processing steps (e.g., forming, cutting, puncturing) to create the final product or medical device, i.e., a barbed microcatheter with barbs and an exit opening.

5, in one embodiment, the microcatheter blank 128 is preferably positioned between an upper die 138 and a lower die 140 of a press or press die. In one embodiment, the upper die 138 and the lower die 140 preferably move toward one another to compress and/or form the microcatheter blank 128 therebetween. In one embodiment, when the upper die 138 and the lower die 140 are moved to a closed position, the dies compress the microcatheter blank 128 to form a first flattened region 142 and a second flattened region 144 that extend along the sides of the microcatheter blank 128. In one embodiment, the first flattened region 142, 144 preferably extend along the length of the microcatheter blank. In one embodiment, the upper die 138 and the lower die 140 preferably have opposing surfaces that form a central portion of the microcatheter blank 128 into the hollow tube 102 of the barbed microcatheter shown in FIGS. 2A-2E and 3 and described above. The hollow tube 102 preferably includes an elongated lumen 122 extending along its length.

Figure 6 shows an end view of the microcatheter blank 128 after it has been molded and/or formed by the upper die 138 and lower die 140 shown in Figure 5. The microcatheter blank 128 desirably includes a first flattened region 142 extending along one side of the microcatheter blank 128 and a second flattened region 144 extending along an opposing second side of the microcatheter blank. The hollow tube 102 described above in Figures 2A-2E and 3 preferably extends along the length of the microcatheter blank 128. The hollow tube 102 desirably has an elongated lumen 122 extending along the length of the hollow tube 102. The pressed microcatheter blank 128 with the first and second flattened regions 142, 144 preferably has a width _W2 of about 0.75 to 3 mm. The first and second planarized regions 142, 144 preferably have a thickness _T2 that is approximately 10-30% of the outer diameter _OD1 of the hollow tube .

Referring to FIG. 7, in one embodiment, rather than using the upper and lower press dies 148, 150 shown in FIG. 5, the microcatheter blank 128 shown in FIG. 6 and described above may be formed using opposing press rollers 138', 140' that engage the upper and lower sides of the microcatheter blank 128 to form the first and second flattened areas 142, 144 (FIG. 6) and the hollow tube 102 shown in FIGS. 2A-2E and 3 and described above.

8, in one embodiment, the microcatheter blank 128 having flattened regions 142, 144 (FIG. 6) can be placed into a cutting die 146 having an upper cutting die 148 and a lower cutting die 150 having cutting teeth 149. In one embodiment, the upper and lower cutting dies 148, 150 can be moved to a closed position after which the cutting teeth 149 engage the first and second flattened regions 142, 144 (FIG. 7) of the microcatheter blank 128 (FIG. 6) to form barbs 108 (FIG. 2A) that extend along the length of the hollow tube 102. In one embodiment, rather than using a cutting die, the barbs 108 can be formed using a cutting instrument such as a razor blade that cuts the first and second flattened regions 142, 144 of the microcatheter blank 128 to form the barbs (FIG. 6). In one embodiment, the barbs 108 may be formed using one or more lasers that cut the first and second flattened regions 142, 144 (FIG. 6) of the microcatheter blank 128.

9, in one embodiment, after the barbs 108 are formed from the first and second flattened regions 142, 144 (FIG. 6), the microcatheter blank 128 preferably includes a hollow tube 102 having spaced apart barbs 108 protruding from opposite sides of the hollow tube 102. The hollow tube 102 preferably includes an outer wall 116 having an outer surface 118 and an inner surface 120 defining an elongated lumen 122 extending along the length of the hollow tube 102.

10A and 10B, in one embodiment, a needle 152 having a sharpened tip 154 may be utilized to form a fluid exit opening 110 (FIG. 2A) in the outer wall of a hollow tube 102 (FIG. 9). The sharpened tip 154 of the needle 152 preferably has a tapered region 156 such that the cross-sectional diameter of the needle 152 increases in size between the distal-most end of the tapered region 156 and the proximal end of the tapered region 156. The tapered region 156 of the sharpened tip 154 preferably allows for the formation of a fluid exit opening in the hollow tube of the barbed microcatheter, as described in more detail herein. Furthermore, in one embodiment, the tapered region 156 of the sharpened tip 154 preferably allows for the formation of fluid exit openings of different sizes (e.g., different diameters) in the hollow tube of the barbed microcatheter. Thus, the needle 152 may be used to form fluid exit openings having the same size or fluid exit openings having different sizes.

11, in one embodiment, the microcatheter blank 128 (FIG. 9) having a hollow tube 102 and barbs 108 extending from its sides can be placed into a fluid outlet opening die 158 used to form a fluid outlet opening 110 (FIG. 2A) in the hollow tube 102. In one embodiment, one or more of the needles 152 shown in FIGS. 10A-10B and described above can be introduced into the fluid outlet opening die 158 to create the fluid outlet opening 110 in the hollow tube 102 of the microcatheter blank 128. In one embodiment, the needles 152 can be slid in and out of the fluid outlet opening die and/or rotated about their longitudinal axis to form the fluid outlet opening 110 in the hollow tube 102 of the microcatheter blank.

12, in one embodiment, the microcatheter blank shown in FIG. 9 is preferably converted into a barbed microcatheter 100 having spaced apart fluid exit openings 110 after the needle 152 (FIG. 11) and the fluid exit opening die 158 of FIG. 11 are utilized to form the fluid exit openings 110 in the hollow tube 102. In one embodiment, the fluid exit openings 110 can be round holes or circular openings formed in the outer wall of the hollow tube 102. The fluid exit openings 110 can be evenly spaced apart from one another along the length of the hollow tube. The fluid exit openings 110 can have the same size or can have different sizes. In one embodiment, the size of the fluid exit openings increases between the distal and proximal ends of the hollow tube.

In one embodiment, the press die shown in FIG. 5, the press roller shown in FIG. 7, and the cutting die shown in FIG. 8 may have needles incorporated therein, so that the fluid exit openings may be formed at the same time that the first and second flattened regions 142, 144 (FIGS. 5 and 7) are formed or the barbs 108 are cut (FIG. 8).

13, in one embodiment, the barbed microcatheter 200 preferably comprises a hollow tube 202 having an elongated lumen 222 extending along its length. In one embodiment, the barbed microcatheter 200 preferably comprises fluid exit openings 210 spaced apart from one another along the length of the hollow tube 202. In one embodiment, the diameter of each fluid exit opening 210 may vary in size between the proximal end of the hollow tube 202 (e.g., the end adjacent the tissue anchor) and the distal end of the hollow tube 202 (e.g., the end adjacent the surgical needle). In one embodiment, a first fluid exit opening 210A near the proximal end 204 of the hollow tube 202 (e.g., the end near the tissue anchor) has a first diameter _D2 that is larger than a second fluid exit opening 210B having a second diameter _D3 . The size of the fluid outlet openings gradually decreases along the length of the hollow tube (e.g., gradually decreases between the proximal and distal ends of the hollow tube), with openings closer to the fluid source being smaller and openings further away from the fluid source being larger in order to maintain a constant flow of fluid from the fluid outlet openings.

14A and 14B, in one embodiment, the fluid outlet opening die 158 shown in FIG. 11 and described above may be utilized to form a fluid outlet opening in the hollow tube of the barbed microcatheter. In one embodiment, a pair of needles 152A, 152B having the same diameter may be utilized to puncture the hollow tube to form fluid outlet openings having different sizes. In one embodiment, the first needle 152A is inserted to a greater depth than the second needle 152B. The size of the hole depends on how far the needle is pushed into the hollow tube. As a result, the first fluid outlet opening 210A (FIG. 13) formed by the first needle 152A is larger in diameter and/or size than the second fluid outlet opening 210B (FIG. 13) formed by the second needle 152B. In one embodiment, multiple (e.g., 10-50) needles may be used to form multiple spaced apart fluid outlet openings extending along the length of the barbed microcatheter. The needles can operate together or independently to form spaced apart fluid exit openings.

15A and 15B, in one embodiment, the fluid outlet opening die 258 can be used to form a barbed microcatheter with fluid outlet openings having different sizes. In one embodiment, the fluid outlet opening die 258 can include a larger diameter needle 252A and a smaller diameter needle 252B. In one embodiment, the larger diameter needle 252A can be advanced into the fluid outlet opening die 258 to puncture the hollow tube to form the larger first fluid outlet opening 210A (FIG. 13) in the barbed microcatheter, while the smaller diameter needle 252B can be utilized to puncture the hollow tube to form the smaller second fluid outlet opening 210B in the barbed microcatheter. In one embodiment, the fluid outlet opening die can include multiple needles (e.g., 10-50 needles) with increasing diameters to form fluid outlet openings with increasing sizes and/or diameters.

In one embodiment, the fluid exit opening of the barbed microcatheter may include one or more elongated slits. Referring to FIG. 16, in one embodiment, the barbed microcatheter 300 preferably comprises a hollow tube 302 having a proximal end 304 and a distal end 306. The barbed microcatheter 300 preferably has a plurality of barbs 308 protruding from opposite sides of the hollow tube 302. The barbs 308 are spaced apart from one another along the length of the hollow tube 302. In one embodiment, the barbed microcatheter 300 preferably includes fluid exit slits 310 formed in the hollow tube 302 and spaced apart from one another along the length of the hollow tube 302. In one embodiment, the spaced apart fluid exit slits 310 are preferably elongated slits formed (e.g., cut, punctured) in the outer wall of the hollow tube 302, and the slits preferably are in fluid communication with an elongated lumen extending along the length of the hollow tube 302. The longitudinal axis of each fluid exit slit 310 may extend along and/or be parallel to the longitudinal axis of the hollow tube 302.

In one embodiment, the barbed microcatheter desirably includes a tissue anchor 312 secured to the proximal end 304 of the hollow tube 302 and a surgical needle 314 secured to the distal end 306 of the hollow tube 302. The surgical needle 314 may be utilized to position the barbed microcatheter 300 in tissue. After implantation in tissue, the barbs 308 preferably hold the barbed microcatheter in place within the tissue.

17A-17E, in one embodiment, the barbed microcatheter 300 preferably comprises a hollow tube 102 having a fluid exit slit 310 extending through an outer wall 316 of the hollow tube 302. The barbed microcatheter 300 desirably comprises a pair of barbs 308 extending from opposite sides of the hollow tube 302. The barb pairs are preferably spaced apart from one another along the length of the hollow tube. With the exception of the fluid exit slit 310 formed on the upper side of the hollow tube 302, the barbed microcatheter 300 shown and described in FIGS. 17A-17E may have similar dimensions and/or features as the barbed microcatheter shown and described above in FIGS. 1-3.

Referring to FIG. 17D, in one embodiment, the fluid exit slit 310 preferably passes completely through the outer wall 316 of the hollow tube 302 to provide fluid communication between the elongated lumen 322 of the hollow tube 302 and the fluid exit slit 310. As a result, fluid passing through the elongated lumen 322 of the hollow tube 302 can flow through the fluid exit slit 310 to bathe tissue surrounding the outside of the hollow tube 302 with the fluid disposed within the elongated lumen.

Referring to FIG. 18, in one embodiment, the barbed microcatheter 300 (FIGS. 17A-17E) comprises a hollow tube 302 having an outer wall 316, preferably comprising an outer surface 318 and an inner surface 320 surrounding an elongated lumen 322 extending along the length of the hollow tube 302. The barbed microcatheter 300 preferably comprises fluid exit slits 310 formed in the upper side 324 of the hollow tube 302 and spaced apart from one another along the length of the hollow tube. In one embodiment, fluid (e.g., therapeutic fluid) flowing through the elongated lumen 322 preferably passes through the fluid exit slits 310 to bathe the tissue surrounding the barbed microcatheter with the fluid. The barbed microcatheter 300 desirably comprises outwardly extending barbs 308 spaced apart from one another along the length of the hollow tube 302. In one embodiment, the barbs 308 may be a pair of symmetrical barbs projecting from opposite sides of the hollow tube 302.

19, in one embodiment, a fluid exit slit die 358 and a cutting blade 352 may be utilized to form a fluid exit slit (FIG. 18) on the upper side of the hollow tube 302 of the barbed microcatheter 300. In one embodiment, the fluid exit slit die 358 has an upper surface 360 with recesses formed therein that are adapted to seat on the underside of the hollow tube 302, barbs 308, and tissue anchors 312 of the barbed microcatheter 300. In one embodiment, after the barbed microcatheter 300 is positioned on the die 358, a cutting blade 352 with a sharp end may be utilized to form a fluid exit slit 310 (FIG. 18) on the upper side of the hollow tube 302.

20A and 20B, in one embodiment, the cutting blade 352 preferably has a sharp tip 354 that is utilized to form a fluid exit slit in the outer wall of the hollow tube of the barbed microcatheter. In one embodiment, the sharp tip 354 has a cutting edge 362 and angled sidewalls 365, 366 extending proximally from the cutting edge 362. The exact length of the fluid exit slit formed in the outer tube of the barbed microcatheter or microcatheter blank can be controlled by varying the degree to which the sharp tip 354 of the cutting blade 352 is inserted into the hollow tube. In one embodiment, more insertion of the sharp tip forms a longer fluid exit slit and less insertion of the sharp tip forms a shorter fluid exit slit.

Referring to FIG. 21, in one embodiment, after the barbed microcatheter 300 is positioned within a recess formed in the upper surface 360 of the fluid outlet slit die 358, the cutting edge 362 of the cutting blade 352 is preferably juxtaposed with the upper side of the hollow tube 302 of the barbed microcatheter 300.

Referring to FIG. 22, in one embodiment, the cutting edge 362 at the lower end of the cutting blade 352 is lowered onto the exterior surface of the hollow tube 302 to cut and/or pierce the exterior wall of the hollow tube 302.

23, in one embodiment, with the cutting edge 362 of the cutting blade 352 penetrating the outer wall of the hollow tube 302, the cutting blade 352 is moved in a direction DIR1 relative to the hollow tube 302 and the die 358 to form the fluid exit slit 310 on the upper side of the hollow tube 302. In an alternative embodiment, the cutting blade 352 can remain stationary and the die 358 and barbed microcatheter can be moved relative to the cutting edge 362 of the cutting blade 352 to form the fluid exit slit 310 on the upper side of the hollow tube 302.

24, in one embodiment, after the cutting edge 362 of the cutting blade 352 forms the elongated fluid exit slit 310 on the top side of the hollow tube 302, the cutting blade may be retracted so that the hollow tube 302 and die 358 may be indexed to a next position to form another fluid exit slit in the hollow tube. The process may be repeated to form multiple fluid exit slits (e.g., 25 slits, 50 slits, 100 slits) along the length of the hollow tube 302. In one embodiment, the slits may have the same length. In one embodiment, one or more of the fluid exit slits may have different lengths.

25A-25B, in one embodiment, the fluid exit slit 310 (FIGS. 17A-17E) may be formed in the barbed microcatheter by passing a cutting blade 352 (FIG. 20A) through an opening in the body of a fluid exit slit die 458. In one embodiment, the fluid exit slit die 458 preferably includes an upper surface 360 having a recess 365 formed therein that seats a microcatheter blank 128 (FIG. 9) having barbs cut along its sides. In one embodiment, the fluid exit slit die 458 desirably includes a first opening 466 configured to receive a first cutting blade 452A and a second opening 468 configured to receive a second cutting blade 452B. In one embodiment, the cutting edge of each cutting blade 452A, 452B is advanced into a recess 468 formed in the upper surface 460 of the die 458 so that the cutting edge can engage the outer wall of the hollow tube of the catheter blank and form a fluid exit slit in the outer wall of the hollow tube.

25C and 25D, in one embodiment, the first cutting edge 462A of the first cutting blade 452A is advanced to a greater depth than the second cutting edge 462B of the second cutting blade 452B. As a result, the length of the fluid exit slit formed by the first cutting blade 452A is greater than the length of the fluid exit slit formed by the second cutting blade 452B.

FIG 26 illustrates a barbed microcatheter 400 formed utilizing the fluid exit slit die 458 and cutting blades 452A, 452B shown in FIGS. 25A-25D and described above. In one embodiment, the barbed microcatheter 400 comprises a hollow tube 402 having an elongated lumen 422 extending along the length of the hollow tube 402. Barbs 408 protrude from the sides of the hollow tube 402. An anchor 412 is secured to the proximal end 404 of the hollow tube 402 of the barbed microcatheter 400. The barbed microcatheter comprises a first fluid exit slit 410A formed in the outer tube 402 having a first length _L2 greater than a second length _L3 of a second fluid exit slit 410B formed in the outer tube 402. As discussed above, the length of each of the fluid exit slits 410A, 410B can be controlled by the depth of insertion of the cutting edge of the cutting blade 352 (FIGS. 20A and 20B) or by controlling the length of the fluid exit slit cut into the hollow tube 402 as the cutting edge of the cutting blade is moved relative to the hollow tube and a fluid exit slit die that seats on the hollow tube of a microcatheter blank (e.g., microcatheter blank 128 shown in FIG. 9).

In one embodiment, the therapeutic fluid flows in a direction DIR2 through the elongated lumen 422 of the hollow tube 402. The therapeutic fluid flows from a fluid source located at a distal end of the hollow tube 402, preferably spaced from the proximal end 404 of the hollow tube. The first fluid exit slit 410A adjacent the anchor 412 is longer than the second fluid exit slit 410B distal to the first fluid exit slit 410A.

27A, in one embodiment, the barbed microcatheter 500 is preferably used to inject a therapeutic fluid into a patient's tissue, such as a wound of the patient. In one embodiment, the barbed microcatheter 500 preferably comprises a hollow tube 502 having a first end 504 and a second end 506. The barbed microcatheter 500 desirably comprises barbs 508 spaced apart from one another along the length of the hollow tube 502 and projecting from opposite sides of the hollow tube. In one embodiment, the barbed microcatheter comprises a plurality of fluid exit openings 510 formed in the outer wall of the hollow tube 502 and spaced apart from one another along the length of the hollow tube. In one embodiment, the hollow tube 502 has an elongated lumen (e.g., the elongated lumen 122 shown in FIG. 3) extending along the length of the hollow tube and adapted to receive a therapeutic fluid to be infused into the patient's tissue. The fluid exit opening 510 is preferably in fluid communication with the elongated lumen such that fluid flowing through the elongated lumen of the hollow tube can exit the hollow tube via the fluid exit opening 510. In one embodiment, the barbed microcatheter 500 can include a tissue anchor 512 secured to a first end 504 of the hollow tube 502 and a surgical needle 514 secured to a second end 506 of the hollow tube 502.

In one embodiment, the patient's epidermis E has a surgical opening SO formed therein to define a wound W having wound tissue including a subcutaneous layer SL and a fascial layer FL. The wound has a first end 575 and a second end 585 spaced from the first end 575.

In one embodiment, the barbed microcatheter 500 preferably includes a midsection 555 that includes at least some of the fluid exit openings 510 and the barbs 508. In one embodiment, the barbs 508 in the midsection 555 of the barbed microcatheter 500 preferably bite into tissue in the wound W to secure the barbed microcatheter in place in the wound W. In one embodiment, the second end 506 of the hollow tube 502 preferably does not have a fluid exit opening. In one embodiment, the second end 506 of the hollow tube 502 is preferably threaded outside the patient so that the needle 514 can be removed from the second end of the hollow tube, at which time the therapeutic fluid can be directed to the second end of the hollow tube.

27A and 27B, in one embodiment, a method of delivering therapeutic fluid to tissue desirably includes positioning a barbed microcatheter 500 adjacent a first end 575 of a wound W. In one embodiment, a needle 514 is used to create a first tissue opening 595 at the first end 575 of the wound, and a hollow tube 502 is pulled completely through the first tissue opening 595 until the tissue anchor 512 abuts the tissue at the first end of the wound W.

In one embodiment, the needle 514 is used to form a second tissue opening 597 at the second end 585 of the wound W, and the hollow tube 502 is pulled completely through the second tissue opening 597 such that the barbs 508 projecting outwardly from opposite sides of the hollow tube 502 engage tissue within the wound W located between the first end 575 and the second end 585 of the wound W.

In one embodiment, the needle 514 is subsequently passed through the patient's epidermis E such that the needle 514 and the second end 506 of the hollow tube 502 are located outside the patient.

27B, in one embodiment, after the barbed microcatheter 500 is implanted in the wound W, the intermediate portion 555 of the hollow tube 502, including the barbs 508 and the fluid exit openings 510, may extend along a straight path between the first end 575 and the second end 585 of the wound W. The barbs 508 preferably dig into tissue in the wound W to prevent the hollow tube 502 from sliding or moving in a direction designated DIR3. The tissue anchors 512 preferably engage tissue at the first end 575 of the wound W to prevent the hollow tube 502 from sliding or moving in a direction designated DIR4.

In one embodiment, the second end 506 of the hollow tube 502 is cut to remove the needle 514 from the hollow tube 502 and provide access to the elongated lumen extending through the hollow tube 502.

27C, in one embodiment, the wound W may be closed, such as by using sutures, staples, tissue fasteners, and tissue adhesives. A container 599 holding a therapeutic fluid may be coupled to the cut second end 506 of the hollow tube 502 that extends outside the patient to introduce the therapeutic fluid into the hollow tube 502. The therapeutic fluid preferably flows into the elongated lumen of the hollow tube and passes through a fluid exit opening 510 (FIG. 27B) to infuse the therapeutic fluid into the wound W.

28A, in one embodiment, a barbed microcatheter 600 is preferably used to inject a therapeutic fluid into a patient's tissue, such as a wound of the patient. In one embodiment, the barbed microcatheter 600 preferably comprises a hollow tube 602 having a first end 604 and a second end 606. The barbed microcatheter 600 desirably comprises barbs 608 spaced apart from one another along the length of the hollow tube 602 and projecting from opposite sides of the hollow tube. In one embodiment, the barbed microcatheter comprises a plurality of fluid exit openings 610 formed in an outer wall of the hollow tube 602 and spaced apart from one another along the length of the hollow tube. In one embodiment, the hollow tube 602 has an elongated lumen (e.g., the elongated lumen 122 shown in FIG. 3) extending along the length of the hollow tube and adapted to receive a therapeutic fluid to be infused into the patient's tissue. The fluid exit opening 610 is preferably in fluid communication with the elongated lumen such that fluid flowing through the elongated lumen of the hollow tube can exit the hollow tube via the fluid exit opening 610. In one embodiment, the barbed microcatheter 600 can include a tissue anchor 612 secured to a first end 604 of the hollow tube 602 and a surgical needle 614 secured to a second end 606 of the hollow tube 602.

In one embodiment, the patient's epidermis E has a surgical opening SO formed therein to define a wound W having wound tissue including a subcutaneous layer SL and a fascial layer FL. The wound has a first end 675 and a second end 685 spaced from the first end 675.

In one embodiment, the barbed microcatheter 600 preferably includes a midsection 655 that includes at least some of the fluid exit openings 610 and at least some of the barbs 608. In one embodiment, the barbs 608 in the midsection 655 of the barbed microcatheter 600 preferably bite into tissue in the wound W to secure the barbed microcatheter in place in the wound W. In one embodiment, the second end 606 of the hollow tube 602 preferably does not have a fluid exit opening. In one embodiment, the second end 606 of the hollow tube 602 is preferably threaded outside the patient so that the needle 614 can be removed from the second end of the hollow tube, at which time the therapeutic fluid can be directed to the second end of the hollow tube.

28A and 28B, in one embodiment, a method of delivering therapeutic fluid to tissue desirably includes positioning a barbed microcatheter 600 adjacent a first end 675 of a wound W. In one embodiment, a needle 614 is used to create a first tissue opening 695 at the first end 675 of the wound, and the hollow tube 602 is pulled completely through the first tissue opening 695 until the tissue anchor 612 abuts the tissue at the first end of the wound W. The needle 614 is used to make additional indentations into the tissue, such that the hollow tube 602 follows a nonlinear path between the first end 675 and the second end 675, 685 of the wound W.

In one embodiment, the needle 614 is used to form a final tissue opening 697 at the second end 685 of the wound W, and the hollow tube 602 is pulled completely through the second tissue opening 697 such that the barbs 608 projecting outwardly from opposite sides of the nonlinearly configured hollow tube 602 engage tissue within the wound W located between the first end 675 and the second end 685 of the wound W.

In one embodiment, the needle 614 is subsequently passed through the patient's epidermis E such that the needle 614 and the second end 606 of the hollow tube 602 are located outside the patient.

28B, in one embodiment, after the barbed microcatheter 600 is implanted in the wound W, the intermediate portion 655 of the hollow tube 602, including the barbs 608 and the fluid exit opening 610, may extend along a straight path between the first end 675 and the second end 685 of the wound W. The barbs 608 preferably dig into tissue in the wound W to prevent the hollow tube 602 from sliding or moving in a direction designated DIR5. The tissue anchors 612 preferably engage tissue at the first end 675 of the wound W to prevent the hollow tube 602 from sliding or moving in a direction designated DIR6.

In one embodiment, the second end 606 of the hollow tube 602 is cut to remove the needle 614 from the hollow tube 602 and provide access to the elongated lumen extending through the hollow tube 602.

28C, in one embodiment, the wound W may be closed, such as by using sutures, staples, tissue fasteners, and tissue adhesives. A container 699 holding a therapeutic fluid may be coupled to the cut second end 606 of the hollow tube 602 that extends outside the patient to introduce the therapeutic fluid into the hollow tube 602. The therapeutic fluid preferably flows into the elongated lumen of the hollow tube and passes through a fluid exit opening 610 (FIG. 28B) to infuse the therapeutic fluid into the wound W.

While the above description is of embodiments of the present invention, other and further embodiments of the invention may be made without departing from the basic scope of the invention, the scope of which is limited only by the appended claims. For example, the present invention contemplates that any feature shown in any embodiment described herein or incorporated by reference herein may be combined with any feature shown in any embodiment described herein or incorporated by reference herein and still be within the scope of the present invention.

[Embodiment]
(1) A barbed microcatheter for delivering a fluid, comprising:
a hollow tube having a proximal end, a distal end, and an elongated lumen extending between the proximal and distal ends of the hollow tube;
a barb projecting outwardly from said hollow tube;
a plurality of fluid exit openings formed in the hollow tube that are in fluid communication with the elongated lumen of the hollow tube.
(2) The barbed microcatheter of claim 1, wherein the fluid exit openings are spaced apart between the proximal and distal ends of the hollow tube.
3. The barbed microcatheter of claim 1, wherein the fluid exit openings are evenly spaced apart from one another between the proximal and distal ends of the hollow tube.
(4) The barbed microcatheter of claim 2, wherein each of the fluid exit openings has the same size.
(5) The barbed microcatheter of claim 2, wherein two or more of the fluid exit openings have different sizes.

6. The barbed microcatheter of claim 2, wherein the fluid exit opening comprises a round hole.
7. The barbed microcatheter of claim 2, wherein the fluid exit opening comprises an elongated slit.
8. The barbed microcatheter of claim 7, wherein the hollow tube has a longitudinal axis extending between the proximal and distal ends of the hollow tube, and the elongated slit has a length extending along a common axis parallel to the longitudinal axis of the hollow tube.
9. The barbed microcatheter of claim 1, wherein the hollow tube has an exterior surface and an interior surface surrounding the elongated lumen, and the fluid exit opening is formed in the hollow tube and extends from the exterior surface of the hollow tube to the interior surface of the hollow tube and is in fluid communication with the elongated lumen.
10. The barbed microcatheter of claim 9, wherein the inner surface of the hollow tube defines an inner cross-sectional diameter of the hollow tube and the outer surface of the cylindrical wall defines an outer cross-sectional diameter of the hollow tube that is about two times larger than the inner cross-sectional diameter of the hollow tube.

11. The barbed microcatheter of claim 10, wherein the hollow tube has a wall thickness of about 0.125 mm, the outer cross-sectional diameter of the hollow tube is about 0.50 mm, and the inner cross-sectional diameter of the hollow tube is about 0.25 mm.
12. The barbed microcatheter of claim 1, wherein the barbed microcatheter comprises an absorbable biocompatible polymer.
(13) A barbed microcatheter for delivering a fluid to a tissue, comprising:
a hollow tube having a proximal end, a distal end, and an elongated lumen disposed within the hollow tube extending between the proximal end and the distal end of the hollow tube;
a barb projecting outwardly from an outer surface of the hollow tube;
a plurality of fluid exit openings formed on the outer surface of the hollow tube in fluid communication with the elongated lumen of the hollow tube, the plurality of fluid exit openings being evenly spaced from one another between the proximal and distal ends of the hollow tube.
14. The barbed microcatheter of claim 13, wherein each of the fluid exit openings has the same size.
(15) The barbed microcatheter of claim 13, wherein two or more of the fluid exit openings have different sizes.

(16) The barbed microcatheter according to claim 13, wherein the fluid exit opening has a shape selected from the group consisting of a round hole and an elongated slit.
17. The barbed microcatheter of claim 13, wherein the elongated lumen of the hollow tube defines a cross-sectional diameter of about 0.25 mm and the exterior surface of the hollow tube defines a cross-sectional diameter of about 0.50 mm.
(18) an anchor fixed to the proximal end of the hollow tube;
14. The barbed microcatheter of claim 13, further comprising a surgical needle secured to the distal end of the hollow tube.
(19) A barbed microcatheter for delivering a fluid to a tissue, comprising:
a hollow tube having a proximal end, a distal end, and an elongated lumen disposed within the hollow tube extending between the proximal end and the distal end of the hollow tube;
a plurality of barbs projecting outwardly from an outer surface of said hollow tube;
a plurality of fluid exit openings formed in the exterior surface of the hollow tube in fluid communication with the elongate lumen of the hollow tube, the plurality of fluid exit openings being evenly spaced apart from one another between the proximal and distal ends of the hollow tube;
an anchor secured to the proximal end of the hollow tube;
a surgical needle secured to the distal end of the hollow tube, wherein two or more of the fluid exit openings have different sizes, including a first fluid exit opening located adjacent to the anchor having a first size, and a second fluid exit opening located adjacent to the surgical needle having a second size smaller than the first size of the first fluid exit opening.
20. The barbed microcatheter of claim 19, further comprising an antimicrobial agent coating or impregnating the barbed microcatheter.

(21) The barbed microcatheter according to claim 20, wherein the antibacterial agent is selected from the group of antibacterial agents consisting of triclosan, chlorhexidine, povidone-iodine, and silver compounds.
(22) A method of making a barbed microcatheter having a fluid exit opening, comprising the steps of:
compressing a first lateral side and a second lateral side of a polymer blank to form a barbed microcatheter blank, the barbed microcatheter blank including a first flattened region extending along the first lateral side of the barbed microcatheter blank, a second flattened region extending along the second lateral side of the barbed microcatheter blank, and a hollow tube having an elongated lumen located between the first flattened region and the second flattened region;
removing material from the first flattened region and the second flattened region of the barbed microcatheter blank to form barbs projecting outwardly from opposite sides of the hollow tube;
forming a fluid exit opening in a wall of the hollow tube in fluid communication with the elongated lumen of the hollow tube.
(23) compressing a proximal end of the polymer blank to form a tissue anchor connected to the proximal end of the hollow tube;
23. The method of claim 22, further comprising securing a needle to a distal end of the hollow tube.
24. The method of claim 22, further comprising using at least one cutting element to form the fluid exit opening in the wall of the hollow tube.
(25) The step of forming the fluid outlet opening comprises:
forming a first fluid exit opening in the wall of the hollow tube having a first size;
forming a second fluid outlet opening in the wall of the hollow tube having a second size larger than the first size of the first fluid outlet opening.

26. The method of claim 24, wherein the step of forming the fluid outlet openings comprises forming a series of progressively larger fluid outlet openings in the wall of the hollow tube.
27. The method of claim 22, wherein the fluid outlet opening is formed simultaneously during the step of forming the fluid outlet opening.
28. The method of claim 22, wherein the fluid outlet openings are formed independently of one another at different times during the step of forming the fluid outlet openings.
29. The method of claim 24, wherein the at least one cutting element comprises a cutting element selected from the group consisting of a needle, a tapered tip needle, and a cutting blade.
30. The method of claim 23, wherein the tissue anchor connected to the proximal end of the hollow tube comprises a flat tab having a length and a width.

(31) The step of compressing the first lateral side and the second lateral side of the polymer blank comprises:
placing the polymer blank in a press die, the press die having an upper press die portion overlying the polymer blank and a lower press die portion opposite the upper press die portion and below the polymer blank;
and moving the pressing die to a closed position to compress upper and lower surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened regions and the hollow tube.
32. The method of claim 31, wherein the upper press die portion includes a plurality of cutting elements protruding from an underside of the upper press die portion, the cutting elements engaging the hollow tube to form the fluid exit opening in the hollow tube when the press die is in the closed position.
33. The method of claim 22, wherein the step of removing material includes cutting the first and second flattened regions of the barbed microcatheter blank to form the barbs projecting outwardly from the opposing sides of the hollow tube.
(34) The cutting step includes:
placing the barbed microcatheter blank, including the first and second flattened areas and the hollow tube, into a cutting die, the cutting die having an upper cutting die portion and a lower cutting die portion opposite the upper cutting die portion;
and moving the cutting die to a closed position to cut the first and second flattened regions of the barbed microcatheter blank to form the barbs protruding outwardly from opposite sides of the hollow tube.
35. The method of claim 34, wherein the upper cutting die portion includes a plurality of cutting elements protruding from an underside of the upper cutting die portion, the cutting elements engaging the hollow tube to form the fluid exit opening in the hollow tube when the cutting die is in the closed position.

36. The method of claim 22, wherein the step of compressing the first and second lateral sides of the polymer blank comprises using a press roller to compress upper and lower surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened regions of the barbed microcatheter blank and the hollow tube.
(37) A method of making a barbed microcatheter having a fluid exit opening, comprising the steps of:
obtaining a barbed microcatheter blank, the barbed microcatheter blank comprising: a hollow tube having a proximal end, a distal end, and an elongated lumen extending between the proximal and distal ends of the hollow tube; and first and second flattened regions extending along opposite sides of the hollow tube;
removing material from the first flattened region and the second flattened region of the barbed microcatheter blank to form barbs projecting outwardly from the opposing sides of the hollow tube;
using one or more cutting elements to form a fluid exit opening in a wall of the hollow tube that is in fluid communication with the elongate lumen of the hollow tube;
forming a tissue anchor connected to the proximal end of the hollow tube;
and securing a surgical needle to the distal end of the hollow tube.
(38) A method for delivering a therapeutic fluid to tissue, comprising:
positioning a barbed microcatheter adjacent to a wound having a first end and a second end, the barbed microcatheter including: a hollow tube having an elongated lumen extending between the first and second ends of the hollow tube; barbs projecting outwardly from opposite sides of the hollow tube; a fluid exit opening formed in the hollow tube in fluid communication with the elongated lumen; a tissue anchor secured to the first end of the hollow tube; and a needle secured to the second end of the hollow tube;
forming a first tissue opening at the first end of the wound using the needle and pulling the hollow tube completely through the first tissue opening until the tissue anchor abuts tissue at the first end of the wound;
forming a second tissue opening at the second end of the wound using the needle and pulling the hollow tube completely through the second tissue opening such that the barbs projecting outwardly from opposite sides of the hollow tube engage tissue within the wound located between the first and second ends of the wound;
passing the needle through a skin layer of the patient such that the needle and the second end of the hollow tube are exterior to the patient;
severing the second end of the hollow tube to remove the needle from the hollow tube;
and introducing a therapeutic fluid into the cut second end of the hollow tube such that the therapeutic fluid flows into the elongated lumen and passes through the fluid exit opening to infuse the therapeutic fluid into the wound.
39. The method of claim 38, wherein after the step of passing the needle through the skin layer, an intermediate section of the hollow tube including the barb and the fluid exit opening is located between the first end and the second end of the wound.
40. The method of claim 39, further comprising closing the wound such that the intermediate section of the hollow tube is disposed within the closed wound.

41. The method of claim 39, wherein the intermediate section of the hollow tube extends along a straight path between the first end and the second end of the wound.
42. The method of claim 39, wherein the intermediate section of the hollow tube extends along a non-linear path between the first end and the second end of the wound.

Claims (37)

1. A barbed microcatheter for delivering a fluid, comprising:
A longitudinally extending hollow tube,
(i) a proximal end; and
(ii) a distal end; and
(iii) an elongated lumen extending between the proximal end and the distal end of the hollow tube; and
(iv) a hollow tube having a flattened region formed by flattening a portion of a wall of the hollow tube, the portion of the wall extending along the length, the flattened region extending radially outward from the elongated lumen; and
a plurality of planar barbs formed in the flattened region, the barbs projecting radially outward from the elongated lumen in the same plane as the flattened region;
a plurality of fluid exit openings formed in the hollow tube in fluid communication with the elongated lumen of the hollow tube; the fluid exit openings are spaced apart between the proximal and distal ends of the hollow tube;
2. The barbed microcatheter of claim 1, wherein two or more of the fluid exit openings have different opening areas , the fluid exit openings near a fluid source being smaller than the fluid exit openings away from the fluid source. The barbed microcatheter of claim 1, wherein the fluid exit openings are spaced apart from one another between the proximal and distal ends of the hollow tube. The barbed microcatheter of claim 1, wherein the fluid exit openings are evenly spaced apart from one another between the proximal and distal ends of the hollow tube. The barbed microcatheter of claim 3 , wherein each of the fluid exit openings has the same opening area . The barbed microcatheter of claim 3 , wherein two or more of the fluid exit openings have different opening areas . The barbed microcatheter of claim 3, wherein the fluid exit opening has a shape selected from the group consisting of a round hole and an elongated slit. the fluid exit opening comprises an elongated slit;
The barbed microcatheter of claim 3 , wherein the elongated slit has a length extending along the length of the hollow tube. The barbed microcatheter of claim 1, wherein the hollow tube has an outer surface and an inner surface surrounding the elongated lumen, and the fluid exit opening is formed in the hollow tube and extends from the outer surface of the hollow tube to the inner surface of the hollow tube and is in fluid communication with the elongated lumen. The barbed microcatheter of claim 9, wherein the inner surface of the hollow tube defines an inner cross-sectional diameter of the hollow tube, and the outer surface of the cylindrical wall defines an outer cross-sectional diameter of the hollow tube that is approximately twice as long as the inner cross-sectional diameter of the hollow tube. The barbed microcatheter of claim 10, wherein the hollow tube has a wall thickness of about 0.125 mm, the outer cross-sectional diameter of the hollow tube is about 0.50 mm, and the inner cross-sectional diameter of the hollow tube is about 0.25 mm. The barbed microcatheter of claim 1, wherein the barbed microcatheter comprises an absorbable biocompatible polymer. 1. A barbed microcatheter for delivering fluid to tissue, comprising:
A longitudinally extending hollow tube,
(i) a proximal end; and
(ii) a distal end; and
(iii) an elongated lumen disposed within the hollow tube extending between the proximal end and the distal end of the hollow tube; and
(iv) a hollow tube having a flattened region formed by flattening a portion of a wall of the hollow tube, the portion of the wall extending along the length, the flattened region extending radially outward from the elongated lumen; and
a plurality of planar barbs formed in the flattened region, the barbs projecting radially outward from the elongated lumen in the same plane as the flattened region;
a plurality of fluid exit openings in fluid communication with the elongated lumen of the hollow tube, the fluid exit openings being formed on an outer surface of the hollow tube, the fluid exit openings being evenly spaced from one another between the proximal end and the distal end of the hollow tube. The barbed microcatheter of claim 13 , wherein each of the fluid exit openings has the same opening area . The barbed microcatheter of claim 13 , wherein two or more of the fluid exit openings have different opening areas . The barbed microcatheter of claim 13, wherein the fluid exit opening has a shape selected from the group consisting of a round hole and an elongated slit. The barbed microcatheter of claim 13, wherein the elongated lumen of the hollow tube defines a cross-sectional diameter of about 0.25 mm and the outer surface of the hollow tube defines a cross-sectional diameter of about 0.50 mm. an anchor secured to the proximal end of the hollow tube;
14. The barbed microcatheter of claim 13, further comprising a surgical needle secured to the distal end of the hollow tube. 1. A barbed microcatheter for delivering fluid to tissue, comprising:
A longitudinally extending hollow tube,
(i) a proximal end; and
(ii) a distal end; and
(iii) an elongated lumen disposed within the hollow tube extending between the proximal end and the distal end of the hollow tube; and
(iv) a hollow tube having a flattened region formed by flattening a portion of a wall of the hollow tube, the portion of the wall extending along the length, the flattened region extending radially outward from the elongated lumen; and
a plurality of planar barbs formed in the flattened region, the barbs projecting radially outward from the elongated lumen in the same plane as the flattened region;
a plurality of fluid exit openings in fluid communication with the elongate lumen of the hollow tube, the fluid exit openings being formed in an outer surface of the hollow tube, the fluid exit openings being evenly spaced from one another between the proximal end and the distal end of the hollow tube;
an anchor secured to the proximal end of the hollow tube;
a surgical needle secured to the distal end of the hollow tube, wherein two or more of the fluid exit openings have different opening areas including a first fluid exit opening located adjacent the anchor having a first opening area , and a second fluid exit opening located adjacent the surgical needle having a second opening area smaller than the first opening area of the first fluid exit opening. 20. The barbed microcatheter of claim 19, further comprising an antimicrobial agent coating or impregnating the barbed microcatheter. 21. The barbed microcatheter of claim 20, wherein the antibacterial agent is selected from the group consisting of triclosan, chlorhexidine, povidone-iodine, and silver compounds. 1. A method of making a barbed microcatheter having a fluid exit opening, comprising:
compressing a first lateral side and a second lateral side of a polymer blank to form a barbed microcatheter blank, the barbed microcatheter blank including a first flattened region extending along the first lateral side of the barbed microcatheter blank, a second flattened region extending along the second lateral side of the barbed microcatheter blank, and a hollow tube having an elongated lumen located between the first flattened region and the second flattened region;
removing material from the first flattened region and the second flattened region of the barbed microcatheter blank to form barbs projecting outwardly from opposite sides of the hollow tube;
forming the fluid exit opening in a wall of the hollow tube in fluid communication with the elongated lumen of the hollow tube. compressing a proximal end of the polymer blank to form a tissue anchor connected to the proximal end of the hollow tube;
23. The method of claim 22, further comprising: securing a needle to a distal end of the hollow tube. 23. The method of claim 22, further comprising using at least one cutting element to form the fluid exit opening in the wall of the hollow tube. forming the fluid outlet opening,
forming a first fluid outlet opening in the wall of the hollow tube having a first opening area ;
and forming a second fluid outlet opening in the wall of the hollow tube having a second opening area greater than the first opening area of the first fluid outlet opening. 25. The method of claim 24, wherein the step of forming the fluid outlet openings includes forming a series of gradually larger fluid outlet openings in the wall of the hollow tube. 23. The method of claim 22, wherein the fluid outlet opening is formed simultaneously during the step of forming the fluid outlet opening. 23. The method of claim 22, wherein the fluid outlet openings are formed independently of one another at different times during the step of forming the fluid outlet openings. 25. The method of claim 24, wherein the at least one cutting element is selected from the group consisting of a needle, a needle with a tapered tip, and a cutting blade. 24. The method of claim 23, wherein the tissue anchor connected to the proximal end of the hollow tube includes a flat tab having a length and a width. Compressing the first lateral side and the second lateral side of the polymer blank comprises:
placing the polymer blank in a press die, the press die having an upper press die portion overlying the polymer blank and a lower press die portion opposite the upper press die portion and below the polymer blank;
and moving the pressing die to a closed position to compress upper and lower surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened areas and the hollow tube. 32. The method of claim 31, wherein the upper press die portion includes a plurality of cutting elements protruding from an underside of the upper press die portion, and when the press die is in the closed position, the cutting elements engage the hollow tube to form the fluid exit opening in the hollow tube. 23. The method of claim 22, wherein the step of removing material includes cutting the first and second flattened regions of the barbed microcatheter blank to form the barbs that project outwardly from the respective opposing sides of the hollow tube. The cutting step further comprises:
placing the barbed microcatheter blank, including the first and second flattened areas and the hollow tube, into a cutting die, the cutting die having an upper cutting die portion and a lower cutting die portion opposite the upper cutting die portion;
and moving the cutting die to a closed position to cut the first and second flattened regions of the barbed microcatheter blank to form the barbs projecting outwardly from opposite sides of the hollow tube. 35. The method of claim 34, wherein the upper cutting die portion includes a plurality of cutting elements protruding from an underside of the upper cutting die portion, the cutting elements engaging the hollow tube to form the fluid exit opening in the hollow tube when the cutting die is in the closed position. 23. The method of claim 22, wherein the step of compressing the first and second lateral sides of the polymer blank includes using a press roller to compress the top and bottom surfaces of the first and second lateral sides of the polymer blank to form the first and second flattened areas of the barbed microcatheter blank and the hollow tube. 1. A method of making a barbed microcatheter having a fluid exit opening, comprising:
obtaining a barbed microcatheter blank, the barbed microcatheter blank comprising: a hollow tube having a proximal end, a distal end, and an elongated lumen extending between the proximal and distal ends of the hollow tube; and first and second flattened regions extending along opposite sides of the hollow tube;
removing material from the first flattened region and the second flattened region of the barbed microcatheter blank to form barbs projecting outwardly from the opposing sides of the hollow tube;
using one or more cutting elements to form the fluid exit opening in a wall of the hollow tube in fluid communication with the elongate lumen of the hollow tube;
forming a tissue anchor connected to the proximal end of the hollow tube;
and securing a surgical needle to the distal end of the hollow tube.

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