Flexible catheter and related methods

Abstract

Various embodiments of flexible catheters including one or more flexible regions are described herein. In one embodiment, the catheter includes an elongate body having a proximal segment and a distal segment, a first lumen defined by the elongate body and configured to drain fluid from a body region, and a plurality of flexible regions on or within the distal segment of the elongate body. The plurality of flexible regions are collectively configured to passively bend forward. Additionally, at least one of the plurality of flexible regions has a cut depth percentage of about 50% to about 75% of the wall thickness of the elongate body. The function and configuration of the flexible regions described herein reduce the force required by the catheter during insertion into a body lumen.

Description

[Technical field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This international application under the Patent Cooperation Treaty (PCT) claims the benefit of priority to U.S. Provisional Patent Application No. 63 / 193,228, filed May 26, 2021, the contents of which are incorporated herein by reference in their entirety. Literature citations

[0002] All publications and patent applications mentioned in this specification are herein incorporated by reference in their entirety to the same extent as if each individual publication or patent application was specifically and individually indicated to be incorporated by reference in its entirety.

[0003] The present disclosure relates generally to the field of catheterization, and more particularly to the field of urology. Described herein are flexible catheters and associated methods for improving catheterization into body lumens (e.g., urinary tract, nasopharynx, gastrointestinal tract, neurolumens, etc.). [Background technology]

[0004] Physicians use a variety of catheters to perform a variety of tasks in acute and chronic healthcare settings. Common indications for placing a urinary catheter in a patient include: 1) acute or chronic urinary retention (e.g., benign prostatic hyperplasia, atonic bladder, overactive bladder, etc.), 2) urine output measurement, 3) incontinence, and 4) post-surgery patient conditions for the bladder or prostate. Catheters that can be used include Foley catheters, Robinson catheters, Coude® catheters, etc.

[0005] For example, indwelling catheters (also called Foley catheters) are designed to be placed in the urethra for extended periods of time. Foley catheters have an inflatable balloon at their tip that fixes the catheter in place in the bladder to reduce the chance of expulsion from the bladder. In other situations, Robinson or intermittent catheters may be used to drain urine from the bladder for short periods of time. Unlike Foley catheters, they do not have a balloon at their tip and are therefore not self-fixating. Yet another option may be the Coud® catheter, which has a curved tip with or without a balloon (as described above), the purpose of the curve being to facilitate insertion of the tip through the urethral structure or prostatic obstruction (e.g., in cases of benign prostatic hyperplasia). Additionally or alternatively, the catheter may include a temperature probe thereon or one or more irrigation lumens that carry irrigation fluid (e.g., chemotherapy, saline, rinse, etc.) to the bladder. It is primarily used to irrigate the bladder in cases of hematuria with or without the presence of blood clots in the bladder.

[0006] Not only does the wide variety of adult catheters cause confusion for hospital staff as to which catheter to use in which cases, but even the most common adult urinary catheters come in a variety of diameters, ranging from 12F (4 mm) to 30F (10 mm).

[0007] If the catheter is not placed properly, various complications can occur, including bleeding (gross hematuria), urethral injury (e.g., urethral stricture, occurrence of false passage, difficulty in future catheter insertion, etc.), potential sexual side effects on the erectile body (corpus cavernosum) which runs adjacent to the urethra on the side of the urethra, Peyronie's disease (i.e., abnormal curvature of the penis due to scarring on the tunica albuginea layer of the erectile body), urinary tract infection, and urinary retention.

[0008] Furthermore, the wide variety of catheters, each in a variety of sizes, often results in confusion and / or multiple catheters being placed per patient or indication, resulting in excessive medical waste, redundancy, and disruptive workflow.

[0009] Thus, there is a need for a universal catheter that is safe, effective, non-messy, and minimizes medical waste and disruptions to workflow. Summary of the Invention [Problem to be solved by the invention]

[0010] The present invention has been made to solve the problems in the conventional techniques described above. [Means for solving the problem]

[0011] One aspect of the present disclosure is directed to a catheter including an elongate body having a proximal segment and a distal segment, a first lumen defined by the elongate body and configured to drain fluid from a body region, and a plurality of flexible regions on or within the distal segment of the elongate body. In any of the foregoing embodiments, the plurality of flexible regions are configured to passively bend forward upon advancement through a curved path.

[0012] In any of the foregoing embodiments, the cut depth percentage of at least one of the plurality of flexible regions is between about 50% and about 75% of the wall thickness of the elongate body.

[0013] In any of the foregoing embodiments, the percent volume removed from at least one of the plurality of flexible regions is between about 15% and about 20%.

[0014] In any of the foregoing embodiments, the force causing the flexible region to bend is less than the force causing a portion of the elongate body that does not include any of the flexible regions. In any of the foregoing embodiments, the force causing the distal segment to bend forward is less than the force causing the distal segment to bend backward.

[0015] In any of the above embodiments, the percentage of volume removed from at least one of the plurality of flexible regions is between about 15% and about 20%. In any of the above embodiments, the percentage of volume removed from at least one of the plurality of flexible regions is between about 25% and about 35%.

[0016] In any of the foregoing embodiments, at least a subset of the plurality of flexible regions has a combined bend angle of between about 30 degrees and about 200 degrees.

[0017] In any of the preceding embodiments, the catheter is a urinary catheter.In any of the preceding embodiments, the body region includes one of a tissue, an organ, a blood vessel, or a cavity.

[0018] In any of the foregoing embodiments, at least a subset of the plurality of flexible regions extends into the first lumen and further functions as an evacuation port. In any of the foregoing embodiments, the catheter further includes a retention balloon disposed about at least a portion of the distal segment of the elongate body. In any of the foregoing embodiments, the catheter further includes a second lumen configured to inflate the retention balloon.

[0019] In any of the foregoing embodiments, the cut depth percentage of one or more of the plurality of flexible regions is between about 40% and about 50% of the outer diameter of the elongated body.In any of the foregoing embodiments, the cut depth percentage of one or more of the plurality of flexible regions is between about 51% and about 67% of the outer diameter of the elongated body.

[0020] In any of the foregoing embodiments, the cut length percentage of at least a subset of the plurality of flexible regions is between about 10% and about 90%.In any of the foregoing embodiments, the cut length percentage is between about 70% and about 80%.

[0021] In any of the above-described embodiments, the plurality of flexible regions includes three or more flexible regions. In any of the above-described embodiments, the plurality of flexible regions includes three to five flexible regions.

[0022] In any of the foregoing embodiments, the elongated body has a durometer hardness of about 20 Shore A to about 80 Shore A. In any of the foregoing embodiments, the elongated body has a durometer hardness of about 40 Shore A to about 70 Shore A.

[0023] In any of the foregoing embodiments, the distal segment has a length of about 1 cm to about 10 cm.

[0024] In any of the foregoing embodiments, the distal segment has a length of about 3 cm to about 5 cm.

[0025] In any of the foregoing embodiments, the ratio of the outer diameter of the elongate body to the outer thickness of the protrusion at the distal tip of the distal segment is from about 1.0:0.8 to about 1.0:0.2.

[0026] In any of the foregoing embodiments, one or more of the plurality of flexible regions extend through the front sidewall of the elongate body, through the first lumen, and into the luminal surface of the rear sidewall of the elongate body.

[0027] In any of the aforementioned embodiments, one or more of the plurality of flexible regions pass through the front sidewall of the elongate body, extend circumferentially around at least a portion of the first lumen, and extend into the luminal surface of the rear sidewall of the elongate body.

[0028] In any of the foregoing embodiments, a distal-most flexible region of the plurality of flexible regions has a greater cut depth percentage than a subset of the plurality of flexible regions.

[0029] In any of the foregoing embodiments, the cut depth percentage of the distal most flexible region is between about 80% and about 95% of the outer diameter of the elongate body.

[0030] In any of the foregoing embodiments, at least a portion of the elongate body is polygonal in shape. In any of the foregoing embodiments, the polygonal shape is a prism having a trapezoidal base.

[0031] In any of the previous embodiments, the plurality of flexible regions includes a plurality of front flexible regions.In any of the previous embodiments, the catheter further includes a plurality of front flexible regions.

[0032] In any of the foregoing embodiments, the plurality of rear flexible regions each include a groove in the interior sidewall of the first lumen of the elongate body. In any of the foregoing embodiments, the groove in the interior sidewall of the first lumen has a cut depth percentage of between 5% and about 20% of the wall thickness.

[0033] Another aspect of the present disclosure is directed to a catheter including an elongate body having a proximal segment and a distal segment, a first lumen defined by the elongate body and configured to drain fluid from a body region, and at least one flexible region on or in the distal segment of the elongate body.

[0034] In any of the foregoing embodiments, at least one flexible region is configured to bend forward at an absolute bend angle of between about 20 degrees and about 200 degrees.

[0035] In any of the foregoing embodiments, the cut depth percentage of the at least one flexible region is between about 30% and about 70% of the outer diameter of the elongate body.

[0036] In any of the preceding embodiments, the catheter is a urinary catheter.In any of the preceding embodiments, the body region includes one of a tissue, an organ, a blood vessel, or a cavity.

[0037] In any of the foregoing embodiments, at least one flexible region extends into the first lumen and also functions as an evacuation port.

[0038] In any of the foregoing embodiments, the catheter further includes a retention balloon disposed about at least a portion of the distal segment of the elongate body. In any of the foregoing embodiments, the catheter further includes a second lumen configured to inflate the retention balloon.

[0039] In any of the foregoing embodiments, the cut depth percentage is about 40% to about 50% of the outer diameter of the elongated body. In any of the foregoing embodiments, the cut depth percentage is about 58% to about 67% of the outer diameter of the elongated body. In any of the foregoing embodiments, the cut depth percentage is about 50% to about 60% of the outer diameter of the elongated body.

[0040] In any of the foregoing embodiments, the cut length percentage of at least a subset of the plurality of flexible regions is between about 10% and about 90%. In any of the foregoing embodiments, the cut length percentage is between about 70% and about 80%.

[0041] In any of the foregoing embodiments, the elongated body has a durometer hardness of about 20 Shore A to about 80 Shore A. In any of the foregoing embodiments, the elongated body has a durometer hardness of about 40 Shore A to about 70 Shore A.

[0042] In any of the foregoing embodiments, the distal segment has a length of about 1 cm to about 10 cm.In any of the foregoing embodiments, the distal segment has a length of about 3 cm to about 5 cm.

[0043] In any of the foregoing embodiments, the ratio of the outer diameter of the elongate body to the outer thickness of the protrusion at the distal tip of the distal segment is from about 1.0:0.8 to about 1.0:0.2.

[0044] In any of the foregoing embodiments, at least one flexible region extends through the front sidewall of the elongate body, through the first lumen, and into the luminal surface of the rear sidewall of the elongate body.

[0045] In any of the foregoing embodiments, at least a portion of the elongate body is polygonal in shape. In any of the foregoing embodiments, the polygonal shape is a prism having a trapezoidal base.

[0046] In any of the previous embodiments, the plurality of flexible regions includes a plurality of front flexible regions.In any of the previous embodiments, the catheter further includes a plurality of front flexible regions.

[0047] In any of the foregoing embodiments, the plurality of rear flexible regions each include a groove in the inner wall of the first lumen of the elongate body. In any of the foregoing embodiments, the groove in the inner wall of the first lumen has a cut depth percentage of between 5% and about 90% of the wall thickness.

[0048] Another aspect of the present disclosure is directed to a urinary catheter including an elongate body having a proximal segment and a distal segment, the distal segment defining at least one port configured to drain fluid from an organ, a retention balloon disposed about at least a portion of the distal segment of the elongate body, two or more lumens defined by the elongate body, and one or more flexible regions disposed on or in the distal segment of the elongate body.

[0049] In any of the foregoing embodiments, the first lumen is configured to drain fluid from the organ and the second lumen is configured to inflate the retention balloon.

[0050] In any of the foregoing embodiments, the one or more flexible regions are configured to facilitate unidirectional deflection of at least a portion of the distal segment during navigation of the elongate body.

[0051] In any of the above described embodiments, there are two flexible regions on the anterior distal region and two flexible regions on the posterior distal region.

[0052] In any of the foregoing embodiments, the two front flexible regions and the two rear flexible regions are generally aligned in the transverse direction.

[0053] In any of the foregoing embodiments, the combined bend angle of the at least two flexible regions is between about 20 degrees and about 70 degrees.

[0054] In any of the foregoing embodiments, the combined bending angle of the at least two flexible regions is between about 60 degrees and about 200 degrees.

[0055] In any of the above described embodiments, there are at least two flexible regions, a first flexible region that is more proximal has a bend angle of about 50 degrees to about 70 degrees, and a second flexible region that is more distal has a bend angle of about 40 degrees to about 80 degrees.

[0056] In any of the foregoing embodiments, one or more of the flexible regions includes a through hole.

[0057] In any of the foregoing embodiments, one or more of the flexible regions includes a blind hole.

[0058] In any of the foregoing embodiments, the one or more flexible regions include a material having a lower durometer than the distal segment surrounding the one or more flexible regions.

[0059] In any of the foregoing embodiments, the one or more flexible regions comprise a material having a lower durometer than the material comprising the elongated body.

[0060] In any of the foregoing embodiments, the one or more flexible regions extend semi-circumferentially around the elongate body.

[0061] In any of the foregoing embodiments, the one or more flexible regions include less material than the distal segment surrounding the one or more flexible regions.

[0062] In any of the above-described embodiments, the elongate body further defines a third lumen and the distal segment further defines an irrigation port, the third lumen configured to transport fluid to the organ through the irrigation port.

[0063] In any of the foregoing embodiments, the distal segment further defines an aperture configured to pass a guidewire therethrough.

[0064] In any of the foregoing embodiments, the organ is a bladder.

[0065] Another aspect of the present disclosure is directed to a method of navigating or positioning a urinary catheter. In some embodiments, the method includes: navigating an elongate body through a patient's urethra; passively deflecting, optionally temporarily and / or optionally unidirectionally, at least a portion of a distal segment of the elongate body during navigation, the deflecting occurring near one or more of the patient's bulbar urethra, membranous urethra, or prostatic urethra, the temporary and unidirectional deflection occurring in a region including one or more flexible regions; inflating a retention balloon disposed about the distal segment of the elongate body to retain at least one region of the distal segment within the patient's bladder, the inflation occurring through an inflation lumen defined by the elongate body and fluidly connected to a space defined by the retention balloon; and drawing fluid from the patient's bladder through at least one port defined by the distal segment and fluidly connected to a lumen defined by the elongate body.

[0066] In any of the foregoing embodiments, the method further includes the step of deflating the retention balloon.

[0067] In any of the foregoing embodiments, the method further includes removing the elongate body from the patient's bladder and urethra.

[0068] In any of the above embodiments, the navigating step further includes inserting the elongate body into the patient's urethra.

[0069] In any of the foregoing embodiments, the method further includes the step of irrigating at least a portion of the bladder.

[0070] In any of the foregoing embodiments, irrigation is provided through at least one irrigation port that is fluidly connected to an irrigation lumen defined by the elongate body.

[0071] In any of the foregoing embodiments, the method further includes the step of removing the particles from the patient's bladder, wherein the distal end of the elongate body defines an aperture therein.

[0072] Another aspect of the present disclosure is directed to a urinary catheter including an elongate body having a proximal segment and a distal segment, a retention balloon disposed about at least a portion of the distal segment of the elongate body, two or more lumens defined by the elongate body, and at least one port defined by the distal segment.

[0073] In any of the foregoing embodiments, the first lumen is configured to drain fluid from the organ and the second lumen is configured to inflate the retention balloon.

[0074] In any of the foregoing embodiments, at least one port is configured to drain fluid from the organ or to pass a guidewire.

[0075] In any of the foregoing embodiments, the at least one port is further configured to facilitate temporary unidirectional deflection of at least a portion of the distal segment during navigation of the elongate body.

[0076] The above is a summary and, by definition, has not been given in detail. These and other aspects, features and advantages of the present technology will now be described with reference to various embodiments and with reference to the accompanying drawings.

[0077] The depicted embodiments are examples only and are not intended to limit the present disclosure. The schematic diagrams are drawn to illustrate features and concepts and are not necessarily drawn to scale. [Brief description of the drawings]

[0078] [Figure 1] Shown is the male urinary tract. [Diagram 2] A typical two-way catheter is shown. [Diagram 3] A typical three-way catheter is shown. [Figure 4A] 1 shows a cross-sectional view of a typical two-way catheter. [Figure 4B] 1 shows a cross-sectional view of a typical three-way catheter. [Diagram 5] 1 shows various planes and sides of the catheter. [Figure 6A] FIG. 1 shows a front view of one embodiment of a flexible catheter. [Figure 6B] FIG. 6B shows a side view of the embodiment of FIG. 6A. [Figure 6C] FIG. 6C shows a side view of the embodiment of FIG. 6B in a bent configuration. [Figure 7A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 7B] 7B shows a cross-sectional view of the embodiment of FIG. 7A along section AA. [Figure 8A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 8B]8B shows a cross-sectional view of the embodiment of FIG. 8A along section AA. [Figure 9A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 9B] 9B shows a cross-sectional view of the embodiment of FIG. 9A along section AA. [Figure 10A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 10B] 10B shows a cross-sectional view of the embodiment of FIG. 10A along section AA. [Figure 11A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 11B] 11B shows a cross-sectional view of the embodiment of FIG. 11A along section AA. [Figure 12A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 12B] 12B shows a cross-sectional view of the embodiment of FIG. 12A along section AA. [Figure 12C] FIG. 12B shows a side view of the embodiment of FIG. 12A in a bent configuration. [Figure 12D] FIG. 12B shows a side view of the embodiment of FIG. 12A in another bent configuration. [Figure 13A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 13B] 13B shows a cross-sectional view of the embodiment of FIG. 13A along section AA. [Figure 13C] FIG. 13B shows a side view of the embodiment of FIG. 13A in a bent configuration. [Figure 14A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 14B] 14B shows a cross-sectional view of the embodiment of FIG. 14A at section DD. [Figure 15A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 15B] FIG. 15B shows a side view of the embodiment of FIG. 15A. [Figure 15C] FIG. 15B shows a rear view of the embodiment of FIG. 15A. [Figure 15D] 15B shows a cross-sectional view of the embodiment of FIG. 15A at section DD. [Figure 16A] 1 shows a side view of another embodiment of a flexible catheter. [Figure 16B] 16B shows a front cross-sectional view of the embodiment of FIG. 16A, taken along section AA. [Figure 16C] 16B shows a rear cross-sectional view of the embodiment of FIG. 16A at section BB. [Figure 16D] 16C shows a side cross-sectional view of the embodiment of FIG. 16B, taken at section CC. [Figure 16E] 16D, a cross-sectional view of the embodiment of FIG. 16D is shown at section DD. [Figure 16F] 16D, a cross-sectional view of the embodiment of FIG. 16D is shown at section EE. [Figure 16G] An enlarged view of a portion of FIG. 16D is shown. [Figure 16H] A three-dimensional perspective view of two flexible regions removed from a tube is shown, showing the volume of each region. [Figure 17A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 17B] 1 shows a front view of another embodiment of a flexible catheter. [Figure 17C] 1 shows a front view of another embodiment of a flexible catheter. [Figure 18A] 13A shows a side view of another embodiment of a flexible catheter in a bent configuration. [Figure 18B] FIG. 18B shows a front view of the embodiment of FIG. 18A. [Figure 19A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 19B] FIG. 19B shows a side view of the embodiment of FIG. 19A. [Figure 19C] 19C shows a front cross-sectional view of the embodiment of FIG. 19B, taken along section AA. [Figure 19D] 19C shows a rear cross-sectional view of the embodiment of FIG. 19B, taken at section BB. [Figure 19E] 19D shows a side cross-sectional view of the embodiment of FIG. 19C, taken at section CC. [Figure 19F] 19E shows a cross-sectional view of the embodiment of FIG. 19E at section DD. [Figure 19G] 19E shows a cross-sectional view of the embodiment of FIG. 19E at section EE. [Figure 20A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 20B] 20B shows a cross-sectional view of the embodiment of FIG. 20A along section AA. [Figure 20C] 1 shows a front view of another embodiment of a flexible catheter. [Figure 20D] 20D shows a cross-sectional view of the embodiment of FIG. 20C at section BB. [Figure 20E] The volume is calculated to show the flexible area within the tube. [Figure 20F] 20F shows material removed from the flexible region of FIG. 20E. [Figure 20G] 20D shows an enlarged view of a portion of the flexible region of FIG. 20C. [Figure 21A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 21B] 21B shows a cross-sectional view of the embodiment of FIG. 21A at section BB. [Figure 22A] 1 shows a front view of another embodiment of a flexible catheter. [Figure 22B] FIG. 22B shows a side view of the embodiment of FIG. 22A. [Figure 22C] 22C shows a front cross-sectional view of the embodiment of FIG. 22B at section AA. [Figure 22D] 22C shows a rear cross-sectional view of the embodiment of FIG. 22B at section BB. [Figure 22E] 22D shows a cross-sectional side view of the embodiment of FIG. 22C, taken at section CC. [Figure 22F] 22E shows a cross-sectional view of the embodiment of FIG. 22E at section DD. [Figure 22G] 22E shows a cross-sectional view of the embodiment of FIG. 22E at section EE. [Diagram 23] 13A shows a side cross-sectional view of another embodiment of a flexible catheter having offset lumens. [Figure 24A] FIG. 1 shows a side view of an embodiment of a flexible catheter having one or more proximally located flexible regions. [Figure 24B] 24B shows a cross-sectional view of the embodiment of FIG. 24A along section AA. [Figure 24C] 24B shows a cross-sectional view of the embodiment of FIG. 24A at section BB. [Figure 24D]24B shows a cross-sectional view of the embodiment of FIG. 24A at section CC. [Figure 24E] 24B shows a side cross-sectional view of the embodiment of FIG. 24A. [Figure 24F] FIG. 24B shows a side view of the embodiment of FIG. 24A in a flexed configuration. [Figure 25A] 1 shows a top view of another embodiment of a flexible catheter having a tapered distal tip. [Figure 25B] 25B shows a side view of the embodiment of FIG. 25A. [Figure 25C] 25B shows a side cross-sectional view of the embodiment of FIG. 25A. [Figure 25D] An enlarged view of a portion of FIG. 25C is shown. [Figure 25E] FIG. 25C shows a three-dimensional perspective view of the distal-most flexible region of the embodiment of FIG. 25B. [Figure 25F] FIG. 25D shows a close-up of the distal-most flexible region of FIG. 25C. [Figure 25G] 25B shows a three-dimensional perspective view of the flexible region of the embodiment of FIG. 25A. [Fig. 25H] Shown are two flexible regions removed from the tube in FIG. 25G to indicate the volume of each region. [Figure 25I] FIG. 25B shows a three-dimensional perspective view of the distal most flexible region (the front flexible region joining the rear flexible region) of the embodiment of FIG. 25A. [Figure 25J] The distal most flexible regions are shown removed from the tube in FIG. 25I to indicate the volume of each region. [Figure 26A] 1 shows a side cross-sectional view of another embodiment of a flexible catheter having one or more polygon-shaped apertures. [Figure 26B] Cross section BB of FIG. 26A is shown. [Figure 27A] 1 shows a top view of another embodiment of a flexible catheter having an elongated flexible bending section. [Figure 27B] 27B shows a cross-sectional view of the embodiment of FIG. 27A. [Figure 28A] 1 shows a top view of another embodiment of a flexible catheter. [Figure 28B] FIG. 28B shows a side view of the embodiment of FIG. 28A. [Figure 28C]28B shows a cross-sectional view of the embodiment of FIG. 28A. [Figure 29A] FIG. 1 shows a perspective view of an elongated body labeled with various measurable parameters. [Figure 29B] 13 shows a close-up cross-sectional view of one embodiment of the cut depth of the flexible region. [Figure 29C] 13 shows an enlarged cross-sectional view of another embodiment of the cut depth of the flexible region. [Figure 29D] 1 illustrates an enlarged cross-sectional view of one embodiment of a flexible region shape. [Figure 29E] 13 shows an enlarged cross-sectional view of another embodiment of a flexible region shape. [Figure 29F] 13 shows an enlarged cross-sectional view of another embodiment of a flexible region shape. [Figure 29G] 13 shows an enlarged cross-sectional view of another embodiment of a flexible region shape. [Figure 30A] Graphs containing data from an ANSYS® computational analysis analyzing various catheter functions with respect to their effect on wall pressure and column strength are shown. [Figure 30B] 1 shows a graph containing data from an ANSYS® computer analysis comparing various standard of care catheters to the catheter embodiments described herein. [Figure 31A] 1 shows an image of a test device for testing insertion force versus insertion depth into a test lumen. [Figure 31B] 1 shows a graph containing data from physical testing comparing various standard of care catheter analogs to various catheter embodiments described herein. [Diagram 32] 1 shows a schematic diagram of a testing apparatus for testing the force required to deflect a distal end portion of an exemplary deflectable catheter. [Diagram 33] 33 shows a graph containing the relationship between deflection amount and deflection force against a fixed curved surface using the test apparatus of FIG. 32 for a catheter including a flexible region extending from an outer surface to an interior region. [Diagram 34] 33 shows a graph containing deflection force data from the test apparatus of FIG. 32 for a catheter that includes an internal (not breaching the outer surface) flexible region. [Diagram 35] 30B is shown normalized to the test rig data of FIG. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0079] The above is a summary and, by definition, has not been described in detail. The above aspects, as well as other aspects, features, and advantages of the present technology, will now be described with reference to various embodiments. The inclusion of the following embodiments is not intended to limit the disclosure to those embodiments, but rather to enable one of ordinary skill in the art to make and use the contemplated invention. Other embodiments may be utilized, and modifications may be made without departing from the spirit or scope of the subject matter. The aspects of the present disclosure described and illustrated herein may be arranged, combined, modified, and designed in various ways, all of which are expressly contemplated and made a part of the present disclosure.

[0080] As described herein, various flexible catheters are described. It will be appreciated by those skilled in the art that although the catheters described herein are described with respect to the urinary system or urinary tract, they may also be used in other peripheral, vascular, or organ systems. For example, the catheters described herein may be configured for use in the nasopharynx, larynx / trachea / bronchi, gastrointestinal tract, neurovascular system, peripheral vascular system, or any other suitable body lumen or organ system.

[0081] The flexible catheters described herein are intended to cause less trauma to the tissues they pass through (tissues within blood vessels) and to the target organs. To achieve this, they are highly flexible, highly bendable, less stiff, and more compliant (e.g., low insertion force), resulting in one or more of the following advantages: less risk of perforation, less formation of strictures and scars (e.g., urethral strictures, esophageal strictures), less spasm (e.g., bladder spasm, laryngeal spasm, vasospasm, etc.), less risk of infection as a result of less trauma, less risk of exposure of various tissue layers, and less risk of mispassage (e.g., urethral mispassage, pseudoaneurysm).

[0082] As used herein, "proximal" means the side of the device closer to or toward the operator, and "distal" means the side away from the operator, toward the patient or target tissue or organ into which the catheter is inserted. Distal end 21 and proximal end 23 are further labeled in Figure 2 for clarity, but it should be understood that this applies to all embodiments described herein.

[0083] As used herein, the "front" refers to the inner radius above or in front of the longitudinal AP (front-to-back) plane of the catheter's bent configuration, as shown in FIG. 5, and the "back" refers to the outer radius below or in back of the longitudinal AP plane of the catheter's bent configuration. Also shown are the inner (M) and outer (L) longitudinal portions of the catheter. Furthermore, in some embodiments described herein, the flexible regions may be arranged transversely, i.e., arranged in a transverse plane. For example, the first flexible region may be located in the front and the second flexible region may be located in the back, but the first and second flexible regions may be arranged transversely, i.e., arranged in a transverse plane, relative to each other. In some embodiments, the flexible regions may be arranged longitudinally, i.e., arranged in a longitudinal plane, as shown in FIG. 5.

[0084] As used herein, "passive" deflection includes deflection as a result of anatomical and physiological curvature, which does not necessarily require an active mechanism (e.g., pull wires, concentric tubes, etc.). Such "active" deflection mechanisms (e.g., pull wires, concentric tubes, etc.) additionally require an actuating mechanism to cause the deflection.

[0085] As used herein, as shown in Figure 29A, "cut length percentage" is defined as the cut length 5700 (i.e., the flexible region length, i.e., the length of the region that has been modified to change the flexibility of that region) divided by the cut length plus the length between cuts (i.e., between the flexible regions) 5710. The cut length percentage may vary depending on the size of the catheter used.

[0086] In some embodiments herein, as shown in FIG. 29A, a "cut depth percentage" is defined as the depth 5720 of a transverse cut perpendicular to the longitudinal axis of the elongate body, as in FIG. 5, in a flexible region, i.e., a region that has been modified to change the flexibility of that region (such as a region of lower durometer material or a region where material has been removed), divided by the outer diameter 5730 of the elongate body, multiplied by 100. The cut extends from the outer surface of the elongate body to a transversely offset interior region of the elongate body. In some embodiments, as shown in FIG. 29B, the flexible region has material removed circumferentially from the inner sidewall of the lumen, such that the transversely offset region includes a cut depth corresponding to where material was removed from the inner sidewall. In another embodiment, as shown in FIG. 29C, the transversely offset interior region penetrates the lumen into the opposite inner sidewall of the lumen, whereby the cut depth percentage includes the inner diameter of the lumen and the depth of the cut into the opposite inner sidewall (e.g., the rear sidewall when the flexible region is in the anterior sidewall). Although cross-sectional views of the flexible regions of various embodiments are provided, it should be understood that the removal of material to form the flexible region may be accomplished in a number of different ways. As shown in FIG. 29D, the edge portion 358 of the flexible region 350 may transition from a convex section 354 near the outer surface 356 of the catheter to a concave section 352. As shown in FIG. 29E, the edge portion 368 of the flexible region 360 may have a convex shape 362. As shown in FIG. 29F, the edge portion 378 of the flexible region 370 may have a concave shape 372. As shown in FIG. 29G, edge portions 388 of flexible region 380 may be inclined (382) (e.g., angled relative to the transverse axis) or vertical (parallel to the transverse axis). This list is not intended to be comprehensive, but rather illustrative of the various shapes of material that may be removed to form the flexible region. The cut depth 5720 may be measured from the rear of the elongated body to an interior region that is transversely offset from the front of the elongated body.

[0087] In other embodiments herein, the cut depth percentage is defined relative to the wall thickness (rather than the outer diameter) of the elongate body. For example, as shown in FIG. 16G, the cut depth percentage relative to the sidewall thickness is about 10% to about 80%, about 20% to about 80%, about 20% to about 30%, about 30% to about 70%, about 70% to about 80%, etc. Embodiments based on sidewall thickness are shown when describing each embodiment.

[0088] "Percent volume removed" or "percent volume" is defined herein as the volume of material removed to create a cut in the sidewall of the catheter (inner or outer sidewall) or the volume of material replaced with a higher or lower durometer material in the sidewall of the catheter (inner or outer sidewall). The volume removed does not necessarily have to penetrate into the lumen of the catheter, but may be superficial to the lumen. In some embodiments, the percent volume removed from the flexible region is a good indicator of the actual material removed because it takes into account material removed circumferentially from the front region, from the rear region, and / or from the sidewall of the lumen.

[0089] The extent of the bare tube for the calculation of the percent volume has already been defined as the cut length of the flexible region. The percent volume of the flexible region is then calculated by determining the volume of material removed relative to the volume of the bare tube (i.e., the unmodified tube), taking into account the material removed from the front, outer, inner and / or rear walls (as applicable).

[0090] In general, the overall length of any of the urinary catheter embodiments described herein may be from about 40 cm to about 60 cm, for example, from about 45 cm to about 50 cm. User-specific catheters for other indications may be of various lengths depending on clinical need. Additionally, any of the embodiments described herein may be modified by one skilled in the art to have a bulbous tip (along a cross section). Any of the embodiments described herein may be modified to have a tapered tip (e.g., as shown in Figures 25A-25B and described in detail elsewhere herein). Any of the embodiments described herein may be modified to have an offset tip (offset from the longitudinal axis of the elongate body) (e.g., as shown in Figures 22A-22G and described in detail elsewhere herein). In any of the embodiments described herein, the distal tip of the catheter or elongate body may be modified to include a bulge (e.g., such as the tips shown in Figures 19A-19G and described in detail elsewhere herein).

[0091] As used herein, a "flexible region" may include any one or more of the following features or functions: through holes, blind holes, apertures, cutouts in the outer diameter of the catheter, cutouts in the inner diameter of the catheter, cutouts across the sidewall of the catheter to allow fluid communication between the lumen and the outside environment, material with a different durometer than the rest of the catheter body, concave surfaces, convex surfaces, etc. Additionally, the flexible region may be elongated, circular, elliptical, rectangular, square, dotted, non-cylindrical, spherical, tapered cylinder, hollow cone, polygonal, etc. in shape. Furthermore, one or more flexible regions may be arranged in a pattern that confers flexibility to the region, for example, the features or characteristics included in the flexible regions may be arranged radially, arranged linearly, located in the front half of the catheter, located in the back half of the catheter, located distal to the irrigation / evacuation port, located proximal to the irrigation / evacuation port, located both distal and proximal to the irrigation / evacuation port, or arranged or positioned in any other manner.

[0092] In some embodiments, flexible regions are created by removing a volume of material to make the region more flexible, or by replacing a volume of material with a material of a different durometer to make the region more flexible. This volume of material may be removed or replaced at the outer surface of the catheter, from the outer surface of the catheter all the way to the lumen, at least a portion of the circumference of the lumen of the catheter, at the back inner wall of the lumen, at the inner region of the sidewall to prevent tearing of the outer surface of the catheter or the luminal surface of the catheter, or elsewhere. The volume removed or replaced may range from about 0.1% to about 95%, for example, from about 0.1% to about 2%, from about 1% to about 5%, from about 5% to about 10%, from about 10% to about 20%, from about 20% to about 30%, from about 30% to about 40%, from about 40% to about 50%, from about 50% to about 60%, from about 60% to about 70%, from about 70% to about 80%, from about 80% to about 90%, or greater than 90%. When a material is replaced with a material of a different durometer, 100% by volume of the flexible region is made up of the material of the different durometer.

[0093] In some embodiments, one or more flexible regions, alone or in combination, are configured to impart a bend in the distal section of the catheter of about 5 degrees to about 180 degrees, about 15 degrees to about 85 degrees, about 20 degrees to about 80 degrees, about 20 degrees to about 60 degrees, about 20 degrees to about 40 degrees, about 15 degrees to about 30 degrees, etc. For example, a first flexible region may impart a bend in the proximal portion of the distal segment of the catheter body of about 15 degrees to about 25 degrees, and a second flexible region may impart a bend in the distal portion of the distal segment of the catheter body of about 50 degrees to about 80 degrees. Bend angle measurements (in degrees) described herein are absolute values ​​measured relative to an initial "flat and horizontal" axis, and not relative values ​​measured relative to the curvature or bending of a more proximal segment of the catheter body. This angle would be relative if it were dependent on the position or orientation of the more proximal portion of the elongate body. In other words, if the catheter were in an unbent, straight configuration, all angle measurements herein would be measured relative to the longitudinal axis of the catheter in its unbent, straight configuration. When illustrating the bend angles of various sections of the catheter, such as in Figures 12D and 13C, some relative bend angles are shown, but their starting points are referenced to an absolute bend starting point (measured relative to an initial "flat and horizontal" axis).

[0094] As shown and described herein, any flexible regions are structured, shaped, and / or otherwise arranged to facilitate forward flexion (e.g., to facilitate unidirectional flexion in the forward direction), although unidirectional flexion backward or in the lateral plane is also contemplated.

[0095] In general, any of the devices described herein may be coated. For example, the coating may be hydrophilic, lubricious, antibacterial, etc. The coating may be silicone, polytetrafluoroethylene (PTFE), silver, etc.

[0096] In general, any of the devices described herein may include zero, one, or two balloons on the elongate body. For example, two-balloon embodiments may be used for obstetric induction of labor and retrograde urethrograms. Two-balloon catheter embodiments may include one or more small holes between the balloons and / or may include a cushion at the tip to mitigate the suction effect of the small holes.

[0097] In general, any of the devices described herein may include or be formed, at least in part, of natural latex, silicone, latex, polyisoprene, silastic latex (e.g., latex with a silicone coating), vinyl, urethane, TPE, etc. The durometer hardness of the material may be from about 20 Shore A to about 80 Shore A, from about 30A to about 70A, from about 25A to about 75A, from about 35A to about 53A, or from about 45A to about 55A, preferably from about 40A to about 70A.

[0098] Generally, any of the devices described herein may be provided in a variety of sizes, such as from about 12 French to about 30 French, from about 14 French to 16 French, about 12 French, about 14 French, about 16 French, about 18 French, about 20 French, about 22 French, about 24 French, about 26 French, about 28 French, about 30 French, etc. One unique feature of the present disclosure is that it allows the user to more easily specify the size of the device, for example, using terms such as small, medium, large, and / or extra large. For example, a small size may include a 14 French catheter, a medium size may include a 17 French catheter, a large size may include a 22 French catheter, and an extra large size may include a 25 French catheter.

[0099] In some embodiments, any of the devices described herein may include one or more indicators or markings to distinguish the front and back sides of the catheter, the front being the bending side (the side having the inner radius when in the bent configuration). For example, the indicators or markings may include different shading or coloring on the front and back sides, printed azimuth lines, dashes, dots or stripes, letters, symbols, etc.

[0100] In some embodiments, as described herein, the bending or deflection of the distal end or portion of the catheter may be temporary, such that the distal end or portion only deflects when resistance is encountered within the body lumen and is otherwise substantially unbent or substantially unprebent. For example, temporary deflection may include bending while passing by the apex of the prostate or only after passing or safely through the prostate, and thereafter assuming a substantially straight profile.

[0101] Generally, any of the devices described herein may be packaged, sold, manufactured, or distributed as a kit. For example, the kit may include a lubricant (e.g., KY jelly), a jelly containing an anesthetic (e.g., lidocaine), and the like. The kit may, in some embodiments, include a drainage bag with a tube (e.g., a spiral tube). In some embodiments, the kit may include one or more catheters, e.g., any combination of small, medium, large, and / or extra large catheters may be included in the kit. The kit may optionally include a syringe with an antiseptic solution to clean the urethral opening before insertion and / or sterile water to fill the balloon of the catheter. Additionally, the kit may optionally include a catheter retention device to secure the catheter to the body (e.g., an adhesive attached to the catheter rotation device to secure the catheter rotation device to the thigh).

[0102] Additionally, many of the embodiments described herein show a distal aperture for draining fluid from the organ. However, it is also contemplated and does not depart from the scope of the present disclosure that, for example, the distal end may not include an aperture. Alternatively, an aperture may be present but used to pass a tracking wire.

[0103] Furthermore, many of the embodiments described herein show a lumen defined by the catheter body for draining fluids from an organ. However, it is equally contemplated that at least a portion of the catheter body, for example, does not define a lumen, and this does not depart from the scope of the present disclosure. For example, the distal end portion of the catheter body may not include a lumen. In such embodiments, the lumen extends to one or more apertures, but terminates at those apertures, thereby allowing drainage, irrigation, and / or balloon irrigation to occur, while maintaining the stiffness characteristics of the catheter beyond where the lumen terminates. For example, in some embodiments, no lumen may be included between about 1.5 cm and about 2.5 cm from the most distal end, or no lumen may be included between about 5 cm and about 6 cm from the most distal end.

[0104] As will be appreciated by those of skill in the art, in embodiments including two or more apertures, the apertures can be on opposite sides of the catheter body (transversely offset), axially or longitudinally aligned, front-located, rear-located, etc., without departing from the scope of the present disclosure.

[0105] Additionally, while the accompanying catheter drawings show only the distal end portion or segment of each embodiment, one of ordinary skill in the art will appreciate that any proximal end feature or proximal end region control mechanism may be used. For example, anchor balloons, valves, connectors, rapid exchange segments, drainage bags, syringes for injecting fluids, actuation mechanisms, and the like may be included at the proximal end of each catheter described herein without departing from the scope and spirit of the present disclosure. In some variations, the proximal end portion or segment may optionally be used as a temperature probe as well as an irrigation lumen.

[0106] Additionally, while one or more flexible regions are shown distally (e.g., distal to the retention balloon), one of ordinary skill in the art will appreciate that one or more flexible regions may be more proximally or proximally of the retention balloon. For example, one or more flexible regions may be about 1 cm to about 12 cm, about 1 cm to about 5 cm, about 5 cm to about 15 cm, about 8 cm to about 12 cm, or about 10 cm proximal to the retention balloon. In one embodiment, one or more flexible regions may include any of the disclosed embodiments described herein, for example, spaced about 2.5 cm proximally from the retention balloon. In some embodiments, the proximal flexible regions may be symmetrical so that bending is not promoted in only one direction. Such proximal flexible regions are discussed in more detail below with respect to FIGS. 24A-24F.

[0107] In any of the embodiments described herein, various optional features may be included, such as a temporary occluder during insertion (e.g., in embodiments having an internal flexible region) or a vacuum source to facilitate complete evacuation of the catheter.

[0108] Various features of any of the embodiments described herein may also be used in urethral dilators. Thus, any of the features of the following embodiments may be used in urethral dilators without departing from the scope of the invention disclosed herein.

[0109] In any of the embodiments described herein, one or more portions of the catheter may be radiopaque, hi one embodiment, the entire length of the catheter is radiopaque.

[0110] Generally, the dimensions shown and described herein are for an 18 French device. As will be appreciated by those skilled in the art, the dimensions may be scaled linearly depending on the size of the device.

[0111] FIG. 1 illustrates the male urinary tract. When a catheter is inserted into the male urinary tract, it passes through the penile urethra 10, into the prostatic urethra 14, past the prostate gland 12, and into the bladder neck 18 of the bladder 16. As shown in FIG. 1, the male anatomy requires the catheter to follow a fairly tortuous path to reach the bladder. In women, the path to the bladder is less tortuous. The catheter is inserted through the urethral meatus, through the urethra, and into the bladder neck. Regardless of the anatomy, catheterization of the urinary tract can be challenging due to sensitive tissues, tortuous anatomy, and other organs (e.g., the prostate) that may impinge on the urinary tract and make it difficult for the catheter to pass. Currently available catheters are difficult to use, making it difficult to know which one to choose. For example, imaging with pre-catheter insertion is not routinely performed, and Foley catheters, Coud® catheters, or Council-tipped guidewires cannot be inserted. Moreover, it may become more difficult after the first attempt due to tissue trauma or damage from the first failed attempt. There may be significant bleeding, and the patient's anxiety, discomfort, and pain increases with each failed attempt. In some cases, the physician may need to resort to flexible cystoscopy or suprapubic tube insertion. Furthermore, for example, adult catheters range in size from 12 French to 30 French, which is the outer diameter of the catheter. However, for patients with a wide range of sizes, it may be difficult to determine which catheter size is appropriate. Furthermore, some catheters only have selected functions, which necessitates switching between different catheters to achieve the intended purpose. For example, as shown by an exemplary catheter 28 in FIG. 2, some catheters include a distal aperture 20 for passive removal of particulates or urine, two-way channels 24, 26 for drainage from the distal aperture 20 and for inflating the balloon, respectively, and / or an inflatable balloon 22 for retention within the bladder.Additionally, as shown, for example, by exemplary catheter 30 in FIG. 3, some catheters include a three-way channel (e.g., lumen 32 for filling the retention balloon, lumen 36 for irrigation, lumen 34 for drainage), an inflatable balloon 38 for retention in the bladder, multiple apertures for particulate removal and / or irrigation, etc. In another embodiment, both irrigation and drainage are accomplished through the same lumen. FIG. 4A further illustrates a cross-sectional view of catheter body 40 defining two lumens: lumen 44 for drainage and lumen 42 for filling or irrigating the retention balloon. FIG. 4B further illustrates a cross-sectional view of catheter body 50 defining three lumens: lumen 54 for drainage, lumen 52 for filling the retention balloon, and lumen 56 for irrigation. Any of the catheters described herein may include any one or more of the features described with respect to FIGS. 2-5, thereby making the catheter multifunctional and reducing the need to use multiple catheters to achieve an intended result for a patient.

[0112] Reference is now made to Figures 6A-6C, which illustrate one embodiment of a flexible catheter. As shown in the unbent configuration in Figures 6A-6B, the elongate body 60 of the catheter defines one or more flexible regions, shown as a plurality of blind or through holes 62 proximal to a distal tip 64. As shown in Figure 6C, the distal end 66 is bent at the flexible region 62. The embodiment of Figures 6A-6C further includes a retention balloon 68 (shown in an uninflated state) disposed proximally from the flexible region 62.

[0113] 7A-7B show an embodiment similar to that of FIGS. 6A-6C, except that in this embodiment, the elongated body 70 defines a single aperture 72 as a flexible region, in which the elongated body 70 bends in one direction. As shown in FIGS. 7A-7B, and in contrast to other embodiments described herein, the flexible region 72 has material removed from the front sidewall, which material removal extends circumferentially around the outer diameter of the catheter, such that the flexible region has a U-shaped cross section, as shown in FIG. 7B. The material removal extends to a surface that lies along the longitudinal axis of the catheter. In the embodiment shown in FIG. 7B, this surface lies between about 40% and about 60% (e.g., about 50%) of the outer diameter. The cut depth percentage 75 of the flexible region 72 is between about 40% and about 60%. As mentioned above, the catheter body 70 defines a lumen 71 therethrough and includes, but is not limited to, a retention balloon 78 (in an uninflated state), and a distal tip 74. The distal tip 74 defines an aperture 73 for passing a guidewire, draining fluids from the organ, or irrigating tissue within the organ. In any of the embodiments described herein, the distal tip aperture 73 may be centered along the axial or longitudinal centerline axis of the catheter body, or may be offset from the centerline axis of the catheter body.

[0114] 8A-8B (FIG. 8B is a cross-sectional view of section AA of FIG. 8A) illustrate the embodiment of FIGS. 7A-7B further including a second flexible region 85 having a tapered wall thickness (distal to proximal) at the distal end of the front surface. For example, at the second flexible region 85 distal to the aperture 82, a first inner wall thickness 85a transitions to a second inner wall thickness 85b, the second thickness 85b being less than the first thickness 85a. The transition between the first and second thicknesses may be gradual, stepped, stepped, or otherwise. For example, the transition may be from about 0.25 mm to about 0.5 mm, or from about 1 mm to about 2 mm. The percentage volume of material removed to create the second flexible region 85 may be from about 5% to about 30%. As mentioned above, the catheter body 80 defines a lumen 81 therethrough and optionally includes a retention balloon 88 (in an uninflated state), and a distal tip 84. The distal tip 84 defines an aperture 83 for passage of a guidewire, for draining fluids from the organ, or for irrigating tissue within the organ.

[0115] 9A-9B illustrate the embodiment of FIGS. 8A-8B further including a second flexible region 95, which includes an inner wall cutout that increases in depth from distal to proximal. For example, the inner wall cutout may be aligned with the tapered decreasing inner wall thickness shown in FIG. 9B, which is a cross-sectional view of section AA of FIG. 9A. Additionally, the second flexible region 95 distal to the aperture 92 includes a series of internal grooves having a sawtooth profile. The distance between the crests 95a and valleys 95b of the sawtooth, as well as the internal heights of the crests and valleys, may be gradually tapered, stepped, stepped, etc. Alternatively or additionally, the cutouts may be gradually increasing in depth as they proceed proximally, or may have an abrupt change in depth as they proceed proximally toward the first flexible region 92. The depth may range from about 0.25-0.5 mm to about 1-2 mm. The percent volume of material removed to create the second flexible region 85 may be from about 10% to about 90%. The cutout may be approximately triangular (with the base of the triangular cutout at the rear of the catheter body), approximately rectangular, approximately a slit, etc. In some embodiments, the cutout in the inner wall thickness does not have the tapered decreasing wall thickness described with respect to Figures 8A-8B. As described above, the catheter body 90 defines a lumen 91 therethrough and includes, but is not limited to, a retention balloon 98 (in an uninflated state) and a distal tip 94. The distal tip 94 defines an aperture 93 for passage of a guidewire, evacuation of fluids from the organ, or irrigation of tissue within the organ.

[0116] 10A-10B illustrate the embodiment of FIGS. 7A-7B further including a second flexible region, which includes a front portion 105a of the catheter body 100, which has a different durometer or material than a rear portion 105b of the catheter body 100 and / or a proximal section of the catheter body 100 (e.g., proximal to the balloon 108 or proximal to the aperture 102). The front portion 105a may be substantially the front half, the front surface, the front quarter, etc. The second flexible region may have a lower durometer (softer) than the remaining portions of the catheter body 100. Alternatively or additionally, the material of the front portion 105a may be different from the rear portion such that the front portion 105a is softer in material properties than the rear portion. As shown in Figure 10B, which is a cross-sectional view of section AA in Figure 10A, the second flexible region 105a extends proximally from the distal tip 104 to or past the distal aperture 102. The second flexible region 105a may become more flexible from distal to proximal, such that it is least flexible at the distal tip 104 and most flexible at the proximal end of the second flexible region. Alternatively, the second flexible region 105a may have a central highly flexible region flanked by two less flexible regions, the highly flexible regions being centered at, surrounding, or at least proximal to the distal aperture 102. As mentioned above, the catheter body 100 defines a lumen 101 therethrough and includes, but is not limited to, a retention balloon 108 (in an uninflated state), and a distal tip 104. The distal tip 104 defines an aperture 103 for passing a guidewire, for draining fluids from an organ, or for irrigating tissue within the organ.

[0117] 11A-11B illustrate the embodiment of FIG. 10A-10B where the second flexible region 115a extends only distally or to the distal end of the distal aperture 112. The second flexible region includes a front portion 115a of the catheter body 110, which has a different durometer or material than a rear portion 115b of the catheter body 110. The front portion 115a may be substantially the front half, the front surface, the front quarter, etc. The second flexible region 115a may have a lower durometer (softer) than the other portions of the catheter body 110. Alternatively or additionally, the material of the front portion 115a may be different from the rear portion 115b such that the front portion 115a is softer in material properties than the rear portion 115b. As shown in FIG. 11B, which is a cross-sectional view of section AA in FIG. 11A, the second flexible region 115a extends from the distal tip 114 to the distal end of the distal aperture 112. The second flexible region 115a may abut the distal aperture 112 or may be merely adjacent to the distal aperture 112 without abutting it. The second flexible region 115a may increase in flexibility from distal to proximal, such that it is least flexible at the distal tip 114 and most flexible at the proximal end of the second flexible region. Alternatively, the second flexible region 115a may have a central high flexibility region and two less flexible regions on its sides. As described above, the catheter body 110 defines a lumen 111 therethrough, includes a retention balloon 118 (in an uninflated state), although this is not required, and includes a distal tip 114. Distal tip 114 defines an aperture 113 for passing a guidewire, for draining fluids from the organ, or for irrigating tissue within the organ.

[0118] 12A-12D show another embodiment of a flexible catheter. As shown in FIGS. 12A-12B, an elongate body 120 defines a lumen 121 therethrough, defines one or more apertures 123 (e.g., for irrigating tissue, draining fluids, etc.), and includes a distal tip or end 124. The elongate body 120 further includes one or more flexible regions 122a in a forward portion of the catheter 120. For example, the flexible region 122a may include a low durometer filler material defined by the region 122a along with one or more relief apertures 127. The relief apertures 127 may provide tension relief and / or increased flexibility in the region 122a. As shown in FIG. 12B, which is a cross-sectional view of section AA of FIG. 12A, the relief apertures 127 extend into the front sidewall, although one of ordinary skill in the art will appreciate that it is not necessary for the relief apertures 127 to extend into the sidewall to increase flexibility in that region. The percent cut depth 125 of the flexible region 122a may be between about 30% and about 70% of the outer diameter 5800. The percent volume of the low durometer filler material in the flexible region 122a may be between about 5% and about 50% of the outer diameter 5800. As shown in FIG. 12A, and as is true for any flexible region described elsewhere herein, each flexible region 122a may include a unique shape, structure, and / or filler material. In this example, one flexible region has a more circular appearance or shape and the other flexible region has a more elliptical appearance or shape.

[0119] Additionally, as best shown in FIG. 12B, the elongate body 120 further includes one or more flexible regions 122b at the rear portion of the catheter 120. The flexible region 122b may include a low durometer filler material, one or more relief apertures, a convex surface, a concave surface, or the like. The cut depth percentage 129 of the flexible region 122b may be about 5% to about 30%. The percent volume of the low durometer filler material in the flexible region 122a may be about 5% to about 40%. In some embodiments, the one or more front flexible regions are substantially the same as the rear flexible region, and in other embodiments, the one or more front flexible regions are substantially different from the one or more rear flexible regions. As discussed above, the catheter body 120 may, but does not necessarily, include a retention balloon 128 (shown uninflated).

[0120] 12C-12D show the flexibility characteristics of the catheter 120. The catheter 120 has high bendability in the flexible regions 122a and 122b. For example, the catheter 120 can bend at an angle A1, A2, A3, or A4 in the flexible region 122a, and each angle is about 10 degrees to about 90 degrees, about 20 degrees to about 80 degrees, about 20 degrees to about 60 degrees, about 15 degrees to about 50 degrees, about 50 degrees to about 90 degrees, about 10 degrees to about 40 degrees, about 20 degrees to about 40 degrees, about 5 degrees to about 50 degrees, about 5 degrees to about 30 degrees, about 10 degrees to about 30 degrees, about 15 degrees to about 25 degrees, etc. In some embodiments, the cumulative bend of A1 and A2, or A3 and A4, is about 20 degrees to about 200 degrees, about 30 degrees to about 90 degrees, about 75 degrees to about 85 degrees, about 80 degrees to about 180 degrees, about 80 degrees, etc. The flexible region of the catheter 120 may be located at a most distal portion or a distal portion about 15 mm to about 60 mm, about 30 mm to about 55 mm, about 50 mm to about 70 mm, about 40 mm to about 80 mm, about 50 mm to about 60 mm, etc., from the distal tip 124. In some embodiments, the angle A2 is greater than the angle A1. In other embodiments, A1 is greater than A2. Furthermore, in some embodiments, the angle A4 is greater than the angle A3. In some other embodiments, A3 is greater than A3. In still other embodiments, A2 may be approximately equal to A1, or A3 may be approximately equal to A4. As mentioned above, the catheter body 120 defines a lumen 121 therethrough, as well as one or more drainage / irrigation apertures 123, etc. Additionally, the catheter 120 optionally includes a retention balloon 128 (in an uninflated state) and a distal tip 124.

[0121] 13A-13C show an embodiment similar to that shown in FIGS. 12A-12D, except that in this embodiment, the catheter body or elongate body 130 includes a plurality of front flexible regions 132a and a plurality of rear flexible regions 132b. In this exemplary, non-limiting embodiment, there are four front flexible regions and four rear flexible regions, but as will be understood by those skilled in the art, the number, spacing, shape, and / or composition of the flexible regions may be varied without departing from the original scope of the present disclosure. In some embodiments, the front flexible region 132a and / or the rear flexible region 132b each include, in part or in whole, a low durometer filler material with one or more relief apertures 137 defined by the region 132a or 132b. The relief apertures 137 may provide tension relief and / or increased flexibility in the region 132a. As shown in FIG. 13A, and as is true for any of the flexible regions described elsewhere herein, each flexible region 132a may include a unique shape, structure, and / or filler material. In this example, the front flexible region 132a has a generally elliptical appearance or shape, while the rear flexible region 132b has a more circular appearance or shape. In some embodiments, adjacent flexible regions 132a may be equally spaced apart, while in other embodiments, adjacent flexible regions 132a may be irregularly spaced apart. For example, adjacent flexible regions 132a may be spaced apart by about 5 mm to about 20 mm, about 10 mm to about 15 mm, about 8 mm to about 18 mm, about 12 mm to about 15 mm, etc. The most distal flexible region may be spaced apart from the distal tip 134 by about 1 mm to about 10 mm, about 3 mm to about 8 mm, approximately 5 mm, about 5 mm to about 15 mm, etc. Additionally, in some embodiments, flexible region 132b is offset transversely but not axially from flexible region 132a, while in other embodiments flexible region 132b is offset both transversely and axially from flexible region 132a. In yet other embodiments, flexible region 132b is offset axially but not transversely from flexible region 132a, resulting in a more anterior flexible region.

[0122] The flexibility characteristics of the catheter 130 are shown in FIG. 13C. The catheter 130 bends at the flexible regions 132a, 132b. For example, the catheter 130 can bend at an angle A5, A6, A7, or A8 at the flexible region 132a, which can be between about 1 degree and about 50 degrees, between about 10 degrees and about 40 degrees, between about 15 degrees and about 25 degrees, between about 10 degrees and about 30 degrees, between about 18 degrees and about 23 degrees, etc. In some embodiments, the cumulative bend of A5, A6, A7, and A8 can be between about 15 degrees and about 200 degrees, between about 60 degrees and about 90 degrees, between about 75 degrees and about 85 degrees, about 80 degrees, etc. In some embodiments, the angles A3 (FIG. 12D), A5, etc., can help facilitate guidance during insertion. The flexible region of the catheter 130 may be at a most distal or distal portion about 15 mm to about 60 mm, about 30 mm to about 55 mm, about 50 mm to about 70 mm, about 40 mm to about 80 mm, about 50 mm to about 60 mm, etc., from the distal tip 134. As mentioned above, the catheter body 130 (FIG. 13B, cross-sectional view of section AA in FIG. 13A) defines a lumen 131 for passing a guidewire, draining fluid from an organ, or irrigating tissue within the organ, as well as one or more drainage / irrigation apertures 133, etc. Additionally, the catheter 130 includes a retention balloon 138 (in an uninflated state) and a distal tip 134, although this is not required.

[0123] 14A-14B (FIG. 14B is a cross-sectional view of section DD of FIG. 14A) show an embodiment similar to that shown in FIGS. 13A-13B, except that the embodiment of FIGS. 14A-14B has multiple front flexible regions 142a and multiple rear flexible regions 142b, which may be blind holes, concave sections of the outer diameter of the catheter, convex sections of the outer diameter of the catheter, sections of a different material than the rest of the catheter body, etc. In this exemplary, non-limiting embodiment, there are nine front flexible regions and nine rear flexible regions, although one of ordinary skill in the art would understand that the number, spacing, shape, and / or composition of the flexible regions may be varied without departing from the original scope of the present disclosure. 12A-13C , e.g., a cumulative bend of about 15 degrees to about 200 degrees, about 60 degrees to about 90 degrees, about 75 degrees to about 85 degrees, about 80 degrees, etc. As described above, the catheter body 140 defines a lumen 141 for passing a guidewire, draining fluids from an organ, or irrigating tissue within the organ, as well as one or more drainage / irrigation apertures 143, etc. Additionally, the catheter 140 includes a distal tip 144 and, optionally, a retention balloon 148 (shown uninflated).

[0124] 15A-15D show another embodiment 150 of a flexible catheter, the flexible catheter 150 including one or more front flexible regions 152a and / or one or more rear flexible regions 152b. For example, the one or more flexible regions 152a may include a series or multiple slits, apertures, etc., separated by one or more flanges 152f, as shown in FIG. 15D. For example, the depth of each slit may be about 25% to about 75% of the diameter of the catheter, and the width of each slit may be about 0.25 mm to about 2 mm. The length of the regions 152a may be about 10 mm to about 50 mm. Additionally, as shown in FIG. 15B, the slits or apertures and one or more of the associated flanges may be angled A9, which may be from about 0 degrees to about 90 degrees, from about 20 degrees to about 70 degrees, from about 30 degrees to about 60 degrees, from about 40 degrees to about 70 degrees, etc., such that the slits or apertures are angled in the direction of the desired bend, yet still promote bending in one direction. Referring now to FIG. 15C, rear flexible region 152b is shown. Rear flexible region 152b includes an axially disposed spine 152c, which may be a different material than the catheter body, etc., and one or more transversely extending apertures 152d, 152e. Axially disposed spine 152c is configured to provide a nearly continuous surface between apertures 152d, 152e to avoid deep transitions and edges. For example, axially disposed spines 152c can prevent pinching and / or abrupt transitions to reduce patient discomfort during insertion and / or removal. Flexible region 152a may (optionally) include axially disposed spines as well.

[0125] The transversely extending apertures may range in size (e.g., depth, amplitude, circumference, radius, diameter, etc.), e.g., long apertures 152d and short apertures 152e. The major axis of each aperture 152d, 152e may range from about 20% to about 80% of the diameter of the catheter. The minor axis of each aperture 152d, 152e may range from about 0.25 mm to about 5 mm. Additionally, one or more of the transversely extending apertures (from the spine) may be in a pattern (e.g., every other one, all long, all short, two short then one long, two long then one short, or other pattern). The extending apertures may be blind holes, through holes, may include materials of different durometer hardness, or other. 15D and as described above, the catheter body 150 defines a lumen 151 for passing a guidewire, draining fluids from the organ, or irrigating tissue within the organ, as well as one or more drainage / irrigation apertures 153, etc. The catheter 150 further includes, but is not limited to, a retention balloon 158 (in an uninflated state) and a distal tip 154.

[0126] In some embodiments, at least a portion of the inner wall along the inner diameter or lumen of the elongate body 160 may be removed to provide one or more flexible regions 162a, 162b, as shown in FIGS. 16A-16D. The flexible region may be a front-located flexible region 162a, or a rear-located flexible region 162b, or both, as shown in FIGS. 16B-16C. In this particular embodiment, there are two front flexible regions and one rear flexible region, although one or more front flexible regions and one or more rear flexible regions are contemplated herein. Additionally, two flexible regions may be spaced apart distally relative to one or more apertures 163, as shown in FIG. 16B, which is a cross-sectional view of section AA of FIG. 16A. Additionally, as shown in FIG. 16A, the flexible regions 162a, 162b may not be visible from the outside of the elongate body 160 because they are internally located. As shown in FIG. 16D, in some embodiments, flexible region 162b is offset transversely from flexible region 162a rather than longitudinally, while in other embodiments, flexible region 162b is offset transversely and longitudinally from flexible region 162a. In yet other embodiments, flexible region 162b is offset longitudinally from flexible region 162a rather than transversely, resulting in a more forward flexible region. FIGS. 16E-16H show cross-sectional views (at sections DD and EE, respectively) of FIG. 16D, illustrating how at least a portion of sidewall 167 of the inner diameter of elongate body 160 has been removed to create flexible regions 162a, 162b. In some embodiments, wall thickness 162c and length 162d of front flexible region 162a may be less than wall thickness 162e and length 162f of rear flexible region 162b to facilitate forward bending. For example, as shown in FIG. 16G, wall thickness 165d is shown, along with rear wall cut depth 165b and front wall cut depth 165c. Front wall cut depth 165c may be about 5% to about 95%, about 20% to about 80%, or about 70% to about 80%. Rear wall cut depth 165b may be about 5% to about 95%, about 5% to about 50%, or about 25% to about 35%.In another embodiment, the area or volume of the flexible regions is the same in the rear and front, or the area or volume of the front flexible region is larger than the area or volume of the rear flexible region to promote forward bending. Figure 16H shows the volume of material removed from the front flexible region 162 and the rear flexible region 162b relative to the tube 169. The percent volume of material 515 removed from the front flexible region 162a is about 20% to about 30%, and the percent volume of material 516 removed from the rear flexible region 162b is about 1% to about 10%, or about 2% to about 5%, relative to the tube 169 enclosing the front flexible region 162a and the rear flexible region 162b.

[0127] 16E-16G, and as described above, the catheter body 160 defines a lumen 161 therethrough, as well as one or more drainage / irrigation apertures 163, etc. The catheter 160 further includes, but is not limited to, a retention balloon 168 (in an uninflated state) and a distal tip 164.

[0128] 17A-17C, various relative positions of an aperture with respect to one or more flexible regions are shown. For example, as shown in FIG. 17A, a catheter 170 defines a lumen 171 for passing a guidewire, draining fluid from an organ, or irrigating tissue within an organ, as well as an aperture 173 that is transversely offset from the flexible region 172c but aligned longitudinally with the flexible region 172c with respect to the longitudinal axis of the catheter body 170. In such an embodiment, the aperture 173 to the side of the flexible region 172c can further increase the flexibility of the catheter body 170 at this location. As shown in FIG. 17A, the catheter body 170 can further include a second flexible region 172a located distal to the flexible region 172c at the distal end of the catheter.

[0129] 17B, ​​the bulbous end 176a of the flexible region 172c may be located proximal to the end 176b of the flexible region 172c, which is located between the aperture 173 defined by the catheter body 170. Such a configuration of the flexible region 172c may cause or encourage the distal end 174 of the catheter body 170 to bend forward. As described above, the catheter body 140 may further define a lumen 171 for passing a guidewire, draining fluid from an organ, or irrigating tissue within the organ, as well as a second flexible region 172a located distal to the flexible region 172c.

[0130] In yet another variation, as shown in FIG. 17C, the catheter body 170 includes a flexible region 172c located between the multiple apertures 173. For example, two apertures may be located proximal to the region 172c and one aperture may be located distal to the region 172c. In another embodiment, any number of apertures may be disposed proximal and / or distal to the region 172c. Furthermore, the flexible region 172c may have any shape, configuration, etc. that facilitates bending. The elongate body 170 may further include a second flexible region 172a located distal to the flexible region 172c. As an alternative to the embodiment of FIG. 17C, the apertures 183 may include a plurality of fenestrated holes or exits defined by the elongate body 180, as shown in FIGS. 18A-18B. 18A-18B, apertures 183 are disposed between flexible regions 182a and 182c, as well as proximal to flexible region 182c. Such apertures 183 may enhance bendability in this region and / or may simply function as irrigation apertures, evacuation apertures, etc. Alternatively, apertures 183 may not be apertures at all, but instead may be regions of different durometer, materials, flexibility, blind holes, etc.

[0131] 19A-19G, an embodiment similar to that of FIGS. 16A-16F is shown, except that the elongate body 190 further includes a distal end portion 194 that includes a narrowed end region 194a when viewed from a side perspective to maintain a substantially constant circumference between the elongate body and the bulge 194b at the distal end. The diameter 194e of the narrowed end region 194a is smaller than the diameter 190d of the catheter body 190, such that the transverse circumference of the bulge 194b is substantially equal to the transverse circumference of the elongate body (e.g., at 190d). Such a relationship between the transverse circumference of the bulge and the transverse circumference of the elongate body may function to prevent widening of the inner circumference of the blood vessel into which the catheter is inserted. The bulge 194b may be located anteriorly or posteriorly, or may extend anteriorly or posteriorly, to facilitate deflection of the distal end in a direction opposite the bulge 194b. The bulge 194b may be defined as a distal end portion having a longitudinal cross-sectional length 194c that is less than a transverse cross-sectional length 194d. Additionally, as discussed above in FIGS. 16A-16F and as shown in FIGS. 19A-19G, at least a portion of the sidewall along the inner diameter of the elongate body 190 may be removed to provide one or more flexible regions 192a, 192b. The flexible region may be a front-located flexible region 192a, or a rear-located flexible region 192b, or both, as shown in FIGS. 19C-19G. Additionally, two flexible regions may be spaced apart distally relative to the one or more apertures 193, as shown in FIG. 19C, which is a cross-sectional view of section AA of FIG. 19B. Additionally, as shown in FIGS. 19A-19B, the flexible regions 192a, 192b may not be visible from the exterior of the elongate body 190 because they are internally located. As shown in Figure 19D, which is a cross-sectional view of section BB of Figure 19B, in some embodiments, flexible region 192b is offset transversely but not longitudinally from flexible region 192a, while in other embodiments, flexible region 192b is offset both transversely and longitudinally from flexible region 192a. In yet other embodiments, flexible region 192b is offset longitudinally but not transversely from flexible region 192a, resulting in a more anterior flexible region.19F-19G show a cross-sectional view of FIG. 19E, illustrating how at least a portion of sidewall 197 (shown in FIG. 19E, which is a cross-sectional view of section CC of FIG. 19C) of the inner diameter of elongate body 190 has been removed to create flexible regions 192a, 192b. Additionally, both FIGS. 19F-19G (FIG. 19F is a cross-sectional view of section DD of FIG. 19E and FIG. 19G is a cross-sectional view of section EE of FIG. 19E) show bulge 194b, which in this embodiment extends rearwardly. In some embodiments, the wall thickness and length of the wall covering the internal cavity of front flexible region 192a may be greater than the wall thickness, area, and length of the wall covering the internal cavity of rear flexible region 192b to facilitate forward bending. In another embodiment, the wall thickness, area, and length of the rear and front flexible regions are the same, or the wall thickness, area, and length of the rear flexible region are greater than the wall thickness, area, and length of the front flexible region.

[0132] 19A, the area proximal to the balloon 198 may include an orientation marker 199 (e.g., shown as a stripe). This marker may be located on the front side of the elongate body 190 to allow the user to see the orientation of the catheter after insertion. Thus, the user can know which direction the distal deflection is occurring because the distal deflection is unidirectional in the forward direction. Alternatively, the marker may be located on the back or another side of the elongate body 190 to communicate the orientation of the catheter during or after insertion.

[0133] 19A and 19F-19G, and as described above, the catheter body 190 defines a lumen 191 therethrough, as well as one or more guidewire passage / drainage / irrigation apertures 193, etc. Additionally, the catheter 190 optionally includes a retention balloon 198 (in an uninflated state), and a distal end region 194.

[0134] Figures 22A-22G show another embodiment of a flexible catheter similar to the embodiment of Figures 16A-16F, except that this embodiment includes an asymmetric tip. As shown in Figures 22A-22C (Figure 22C is a cross-sectional view of section AA of Figure 22B), an elongate body 220 defining an aperture 223 and a lumen 221, and including (but not required to include) a balloon 228, includes a distal end region 224 and optionally a marker 229, as described elsewhere herein.

[0135] The distal end region is longitudinally offset (224b) as shown in Figures 22B and 22E. The circumference or diameter of the distal end region is the same as the circumference or diameter of the remainder of the catheter body 220, but extends rearward (or alternatively forward). For example, the longitudinal offset 224b may be from about 0.5 mm to about 5 mm. The elongate body 220 further includes one or more front flexible regions 222a and / or rear flexible regions 222b, as described elsewhere herein (at least with respect to Figures 16 and 19). Cross-sectional views are also shown in Figures 22F-22G, which show the flexible regions 222a, 222b, the longitudinally offset distal end 224b, and the lumen 221.

[0136] 23, but also applicable to all embodiments shown and / or described herein, the elongate body 230 may define a lumen 231 that is offset from the centerline axis of the elongate body 230. For example, the front inner wall 231a may be thinner than the rear inner wall 231b. In other words, material may be added to the rear inner wall of the lumen of the elongate body 230 and / or material may be removed from the front inner wall of the lumen of the elongate body 230 (e.g., to maintain a desired French size of the catheter). Such a thinned inner wall 231a may facilitate unidirectional bending in the forward direction. As will be appreciated by those skilled in the art, the rear wall may be thinner than the front wall to facilitate bending backward. Furthermore, as described above, the catheter body 230 may include one or more flexible regions 232a, 232b and may define one or more apertures 233. The elongate body 230 includes a distal tip 234, as shown in FIG. 23, that includes a rearward bulge or bump 234b such that the diameter of the distal tip 234 is larger than the diameter of the elongate body 230.

[0137] 20A-20B show another embodiment of a flexible catheter. As shown in FIG. 20B, a cross-sectional view of section AA of FIG. 20A, a plurality of flexible regions 202a, 202b, 202c...202n extend from just distal to balloon 208 to near distal end 204 of elongate body 200. Each flexible region 202 includes an inner wall notch or corrugation. Each notch is defined by a cut depth 205 and a wavelength 203. For example, as shown in FIG. 20B, the plurality of flexible regions 202 resemble waves, or in other words, sinusoidal, although other types of notches (e.g., square, sawtooth, etc.) are also contemplated. By way of non-limiting example, the amplitude may be about 0.2 mm to about 0.6 mm, or about 0.4 mm, and the wavelength may be about 2 mm to about 4 mm, or about 3 mm. Optional balloon 208 is also shown, as is lumen 201 defined by elongate body 200.

[0138] 20C-20G show an embodiment similar to that of FIGS. 20A-20B, except that elongate body 5200, defining lumen 5201 and including distal tip 5204, includes multiple flexible regions, each of which, 5202a, 5202b, 5202c, ... 5202n, is elongated along the circumferential surface of the lumen (i.e., material has been removed from the lumen, but not to the outer surface of the elongate body). FIG. 20C shows a cross-sectional view. FIG. 20D shows a cross-sectional view of section BB of FIG. 20C of flexible region 5202a. As shown in FIGS. 20E-20F, the percent volume 5220 removed from tube 5210 for flexible region 5202a is about 10% to about 30%, or about 15% to about 20%. FIG. 20G shows the cut depth relative to the wall thickness of the flexible region. The wall thickness 5810 of the catheter 5200 is 100%, and the cut depth percentage 5820 shown is about 50% to about 75% of the wall thickness into the wall.

[0139] 21A-21B (FIG. 21B is a cross-sectional view of section BB of FIG. 21A) show an embodiment similar to that of FIGS. 20A-20B, except that this embodiment includes a plurality of rear flexible regions 216a, 216b, 216c, ... 216n in addition to the plurality of front flexible regions 212a, 212b, 212c, ... 212n described above with respect to FIGS. 20A-20B, except that wavelength 217 is greater than wavelength 219 and rear cut depth 215 is less than front cut depth 213. By way of non-limiting example, amplitude 213 can be from about 0.2 mm to about 0.6 mm, or about 0.4 mm, while amplitude 215 can be from about 0.1 mm to about 0.5 mm, or about 0.3 mm. Additionally, wavelength 219 may be about 2 mm to about 4 mm, or about 3 mm, while wavelength 217 may be about 4 mm to about 8 mm, or about 6 mm. Alternatively, wavelengths 219, 217 may be about the same, and amplitudes 213, 215 may be about the same. As a further alternative, in some embodiments, wavelength 217 may be less than wavelength 219, and amplitude 215 may be greater than amplitude 213. Consistent with the relationship between amplitude and wavelength, some embodiments may have fewer rear corrugations than front corrugations, as shown in FIG. 21B, although variations in which there are about the same number of rear corrugations and fewer front corrugations than rear corrugations are also contemplated. Optional balloon 218 is also shown, as is lumen 211 defined by elongate body 210.

[0140] In any of the preceding embodiments described herein that include one or more flexible regions in a distal segment of the elongate body, the proximal segment of the elongate body may include one or more proximal flexible regions. For example, the various features of elongate body 230 of FIG. 23 (flexible regions disposed on the inner wall of the lumen defined by the elongate body) may be combined with one or more proximal flexible regions in elongate body 240, as shown in FIG. 24E, which includes one or more distal flexible regions 242a, 242b in addition to one or more proximal flexible regions 245a, 245b. Cross-sectional views of each flexible region are shown in FIG. 24B-24D, where FIG. 24B is a cross-sectional view of section AA, FIG. 24C is a cross-sectional view of section BB, and FIG. 24D is a cross-sectional view of section CC. For example, each flexible region 245a, 245b of elongate body 240 may include one or more grooves 247a, 247b of various widths interspersed with mesh or web sections 247c to prevent tissue from becoming pinched between grooves 247a and / or 247b. In some embodiments, each anterior proximal flexible region 245a is transversely aligned with each posterior proximal flexible region 245b. Such transverse alignment allows at least the more proximal region (or the distal region, if applicable) to bend both forward and backward. Figures 24B-24D also show an inflation lumen 242 defined by elongate body 240 for inflating balloon 248 as shown in Figure 24F. The flexible regions 245a, 245b facilitate bending of the proximal segment, for example, to about 180 degrees, about 10 degrees to about 90 degrees, about 20 degrees to about 60 degrees, etc. One skilled in the art will appreciate that although the flexible regions illustrated in Figures 24A-24F are shown as being on the proximal segment of the elongate body, they may similarly be disposed on the distal segment.

[0141] Additionally, any of the preceding embodiments described herein may include a distal tip having a tapered profile in a lateral view, such as the distal tip shown in Figures 25A-25C. Figures 25A-25C (FIG. 25C is a cross-sectional view of section AA in FIG. 25A) show an elongate body 250 including a plurality of front flexible regions 252a, 252b, 252c, and 252d, and a plurality of rear flexible regions 252e, 252f, 252g, and 252h. An outer diameter 256d of the elongate body 250 may be greater than a thickness 256b of the protruding portion of the distal tip 254, such that the outer diameter 256d of the elongate body 250 tapers toward the outer thickness 256b of the protruding portion of the distal tip 254 in the distal segment. For example, the ratio of outer diameter 256d to outer projection thickness 256b may be about 1.0:0.8 to about 1.0:0.2. The range of taper ratio between outer diameter 256d and projection thickness 256b may be about 1.0:0.8 to about 1.0:0.2. The width of the tip at 256c is appropriately sized with thickness 256b to keep the transverse circumference of the tip constant to be equal to or less than the circumference of the round body (i.e., at 256d) to prevent the inner circumference of the anatomical lumen from being widened, and the width of tip 256c may also be equal to or less than outer diameter 256d to further prevent the anatomical lumen from being widened.

[0142] 25D-25F (FIG. 25F is a portion of section AA of FIG. 25A) show various cut depth percentage flexible regions of elongate body 250 in an enlarged cross-sectional view, a three-dimensional cross-sectional view, and another enlarged cross-sectional view, respectively. The cut depth percentages (defined as the ratio of cut depth to outer diameter 256d) of the plurality of front flexible regions 252b, 252c, 252d at 253a and 253b are about 10% to about 70%. The cut depth percentage of the most distal front flexible region 252a is greater than the cut depth percentages at 252b, 252c, 252d to facilitate bending at the first region at 252a. For example, the cut depth percentage of the most distal front flexible region at 253a may be about 25% to about 75%. The total cut depth percentage 255 of distal-most flexible region 252a is about 60% to about 95%, or about 80% to about 95%, or about 90% to about 95%. Additionally, as shown in FIGS. 25C and 25D, optional rear flexible regions 252e, 252f, 252g, and 252h each include a groove in an inner sidewall of lumen 281a and a rear wall 281b of elongate body 250. The cut depth percentage 257 (relative to the outer diameter of the elongate body) of rear grooves 252e, 252f, 252g in inner sidewall 281b may be between 5% and about 20%, and the cut depth percentage 251 (relative to the outer diameter of the elongate body) of 252h is equal to or greater than the cut depth percentage of 252e, 252f, or 252g and is within the range of about 5% to about 60%. The cut depth percentage 251 of the flexible region 252h relative to the thickness 259 of the rear sidewall 281b is about 60% to about 70%.

[0143] In some embodiments, front flexible region 252a is joined to rear flexible region 252h, thereby removing at least a portion of the interior luminal sidewall 410 between front flexible region 252a and rear flexible region 252h, as shown in Figures 25I-25J. In such embodiments, the volume percentage will be a representation of the sum of the material removed from both regions (front material 440 removed from region 252a and rear material 430 removed from region 252h) and the lumen wall material 420 removed from region 410 between front region 252a and rear region 252h, as shown in Figures 25I-25J.

[0144] As shown in FIG. 25J, the volume percentage of the distal most flexible region, including the anterior material removal 440 on the anterior side, the posterior material removal 430 on the interior side, and at least a portion of the circumference between the anterior and posterior sides within the lumen 420, is about 20% to about 40%, preferably about 25% to about 35%.

[0145] In some embodiments, front flexible region 252b is separate from rear flexible region 252e, as shown in Figures 25G-25H, but collectively these regions facilitate bending of the catheter in a forward direction. In such embodiments, the volume percentage is a representation of the sum of the material removed from both regions (front material 540 removed from region 252b and rear material 530 removed from region 252e) relative to the tube 500, as shown in Figures 25G-25H. The total volume percentage is about 20% to about 40%, and preferably about 25% to about 35%.

[0146] 25H, the volume percent of the front flexible region 252b (for example) including the front material removal 540 and some material removal around the circumference of the lumen may be about 20% to about 40%, or about 25% to about 30%, and the volume percent of the rear flexible region 252e (for example) including the rear material removal 530 may be about 0.1% to about 2%, or about 0.5% to about 10%.

[0147] Furthermore, any of the preceding embodiments described herein may include an elongate body having a polygonal cross section, such as the elongate body shown in Figures 26A-26B. The elongate body 260 shown in Figures 26A-26B defines a lumen 261 therethrough and includes a distal tip 264. In this embodiment, the polygonal shape of the body (narrow front width 263a and wider rear width 263b) is angled to bend more easily forward when axial force is applied, as shown in Figure 26B, which shows cross section B-B of Figure 26A. For example, rear width 263b may be from about 2 mm to about 5 mm, while front width 263a may be from 1 mm to about 3 mm. In one embodiment, material is added to the rear of the catheter, e.g., the rear or rear inner wall of the lumen of catheter body 260, such that the rear width is wider than the front width. In another embodiment, material is added to the rear side of the outer surface of elongate body 260 to create a polygonal shape that preferentially bends forward. Additionally, while a trapezoidal polygon (i.e., a trapezoidal-based prism or a three-dimensional trapezoid) is shown in Figures 26A-26B, one of ordinary skill in the art will appreciate that any polygonal shape is within the scope of the present disclosure, including, but not limited to, rectangular (i.e., rectangular-based prism, rectangular cuboid, rectangular parallelepiped), triangular (i.e., triangular prism, rectangular-based elongate prism), any flat or straight surface that can be replaced by a curved surface, and others.

[0148] In some embodiments, the flexible region may include an elongated aperture (e.g., as shown in FIGS. 27A-27B). The elongated body 270 shown in FIGS. 27A-27B defines a lumen 271 therethrough and includes an elongated flexible region 272. The cut length percentage 276 of the flexible region 272 may be about 5% to about 90% of the length of the elongated body 270, or about 15% to about 30% of the length of the elongated body 270. The flexible region 272 may be such that it extends into the lumen 271 such that the lumen 271 has an elongated trough opening, which is the flexible region 272. As shown in FIG. 27B, which is a cross-sectional view of section AA of FIG. 27A, the flexible region 276 may be generally "U" shaped, e.g., "U" shaped such that the interior angles 277a, 277b at the ends of the flexible region are curved. Although a "U" shaped bend is shown, sharp corners, angled corners, etc. are contemplated herein as will be understood by one of ordinary skill in the art. The features of flexible region 272 may apply to any of the flexible regions described elsewhere herein.

[0149] In another embodiment, as shown in Figures 28A-28C (Figure 28C is a cross-sectional view of section AA in Figure 28A), the elongate body 280 may include multiple flexible regions 282 (e.g., 282a, 282b, 282c, 282d, 282e). One or more of the flexible regions may include an aperture such that the flexible region extends through the front sidewall 288a, through the lumen 281, and through the luminal surface 287 of the rear sidewall 288b (so as not to breach the outer surface of the rear sidewall 288b), such that the cut depth percentage (not including the rear wall depth cut) in one or more of the flexible regions 282 is between about 30% and about 70%. The cut depth percentage 285a in one or more of the flexible regions is between about 50% and about 95%. For example, the cut depth for a catheter with an outer diameter of 6 mm may be about 2.5 mm to about 3.5 mm. Additionally, the cut depth percentage 285a of each of the flexible regions 282 is about 5% to about 55%. The volume percentage in one or more of the flexible regions is about 10% to about 40% or about 25% to about 35% (representations of material 530, 540 removed from the tube 500 are shown in Figures 25G-25H). The flexible regions 282 extend from the front and into the lumen such that material around the lumen is removed circumferentially, as shown in Figure 28C, and some material is also removed at the rear of the lumen.

[0150] 28A-28C, the plurality of flexible regions 282 also include apertures for drainage or flushing as they extend into lumen 281. Elongate body 280 may further include a retention balloon (not shown), one or more proximal indicators (not shown), one or more additional drainage / flushing apertures (shown as 282a-d, 282e), etc. Additionally or alternatively, elongate body 280 may include distal tip 284 of any of the configurations described elsewhere herein (e.g., with respect to FIGS. 19A-19C, 22A-22C, 23, 25A-25C).

[0151] In some embodiments of Figures 28A-28C, the cut depth percentage of the distal most flexible region may be greater than other more proximal flexible regions (e.g., similar to the embodiment described with respect to Figure 25C). Additionally or alternatively, the embodiment of Figures 28A-28C may also include a rear flexible region that includes a groove in the interior sidewall of the lumen of the elongate body, as described with respect to Figure 25C. Additionally or alternatively, the embodiment of Figures 28A-28C may also include a tapered distal tip, as described with respect to Figure 25B.

[0152] As shown in FIG. 28C, the distal tip 284 may define an aperture 283 for passing a guidewire or other instrument therethrough and / or for drainage / irrigation. In another embodiment of FIGS. 28A-28C, the distal tip 284 does not define an aperture. Additionally, while the flexible regions in FIGS. 28A-28C are shown on the front side of the elongate body, one of ordinary skill in the art will appreciate that the flexible regions may be on the rear side of the elongate body. Additionally, the elongate body 280 may include any of the internal flexible regions and / or rear flexible regions described elsewhere herein (e.g., the internal or rear flexible regions of FIGS. 8B, 9B, 16E-16F, 19F-19G, 20B, 21B, 25C). Additionally, the elongate body 280 may include one or more proximal flexible regions described elsewhere herein (e.g., the proximal flexible regions of FIGS. 24A-24D).

[0153] In all of the above-described embodiments of Figures 6A-28C, a balance is struck between maintaining column strength along the length of the catheter (for controlled, predictable pushability) and at the same time limiting the amount of pressure (herein referred to as wall pressure) exerted by the catheter on the anatomical tissue when the catheter is advanced or retracted. In other words, wall pressure is the local maximum pressure exerted by the catheter on the wall. High local pressures can cause deformation of the catheter lumen, which can cause the catheter to get stuck. Because the catheter lumen can have complex stiffness behavior, one way to mitigate significant deformation is to minimize wall pressure.

[0154] The effect of various parameters on column strength and wall pressure, as well as on the insertion force or pressure required to deflect the distal segment of the catheter, was investigated using mechanical testing equipment and computer simulations. For example, as shown in Figure 29A, the cut length, cut depth, cut location, and number of segments were varied to investigate their effect on column strength, wall pressure, and insertion force.

[0155] For example, various catheter designs were analyzed using computer software-based simulations (Ansys® Mechanical software package). Exemplary data from these analyses are shown in Figures 30A-30B. The computer simulation analysis measures the internal forces of the catheter around the flex region (force per insertion distance) as well as the interaction between the catheter and the anatomical pathway (wall pressure, as described elsewhere herein).

[0156] To accurately analyze wall pressures, simplified 3D CAD models of each catheter were created along with tubing representing the anatomical pathways through which the catheters must navigate. A nonlinear contact model with friction was used to model the interaction between the catheter and tubing. Depending on the catheter material and the required simulation accuracy, linear elastic or hyperelastic materials were used. To evaluate catheter flexibility and column strength, the tubing was modeled as a rigid material.

[0157] To evaluate the column strength, an eigenvalue buckling analysis was performed by applying a unit compressive load to the catheter in a linear analysis.

[0158] A simplified 3D CAD model of the catheter was created to be fully parametric. The main input parameters investigated were the catheter material properties, the percentage cut length of the flexible region, and the percentage cut depth of the flexible region, as shown in Figure 30A. The insertion pressure was analyzed and determined, as shown in Figure 30B.

[0159] FIG. 30A shows normalized values ​​of catheter material properties (Young's modulus), cut depth percentage, and cut length percentage measured in the sensitivity analysis (shown as percent local sensitivity on the y-axis). In the sensitivity analysis, the gradient of the output variable with respect to the input variable is calculated. Local sensitivity means the gradient calculated at one point in the multidimensional surface. FIG. 30A shows the gradient of wall pressure and column strength with respect to Young's modulus, cut depth, and cut percentage. The output of the analysis shown on the x-axis is wall pressure, column strength (first buckling mode), and column strength (second buckling mode). Two buckling modes were evaluated because columns typically buckle in two directions perpendicular to the axis of the column. For example, if the axis of the column is Z, buckling can occur in the X-axis or Y-axis. As shown in FIG. 30A, the cut depth percentage had the largest effect on wall pressure and column strength. The cut length percentage also had an effect, but to a lesser extent than the cut depth percentage. Material properties, although important to the overall design, had a smaller effect on the output parameters than cut depth and cut length.

[0160] FIG. 30B shows data from a computer simulation in which a Foley catheter, a Coudes® catheter, and a test catheter (e.g., 28A-28C) were analyzed. The test catheters include multiple flexible regions, each with a cut length percentage of about 70% to about 80% and a cut depth percentage of about 50% to about 70%. The data in FIG. 30B represents the pressure (MPa) that a patient would experience when inserting, advancing, or otherwise forcing a catheter into a patient's lumen (this forcing is represented by the insertion ratio, which is the ratio of the catheter inserted into the bend region to the total length of the catheter).

[0161] As shown in Figure 30B, the Folde® catheter exerts significantly less pressure on the surrounding tissue during insertion than the standard of care Foley catheter or its cousin the Coude® catheter. The maximum pressure exerted by the Folde® catheter during insertion was approximately 39% of that of the Foley catheter and 43% of that of the Coude® catheter.

[0162] In addition to the computer simulation testing, a mechanical test fixture was developed that mimics the size, feel, and tortuosity of the anatomical pathway of a human patient, as shown in FIG. 31A. The mechanical test fixture includes a digital force gauge and a cast gel block 312 with a curved cylindrical lumen 314 that mimics the tortuosity of the urethra. To form the curved urethral lumen of the test fixture, the cast gel was poured into a mold and allowed to harden. The durometer hardness of the cast gel was approximately 10 Shore 00. The inner diameters 316 of the cast catheter insertion pathways were 0.25 inches (0.635 cm), 0.375 inches (0.9525 cm), 0.5 inches (1.27 cm), 0.5625 inches (1.42875 cm), and 0.625 inches (1.5875 cm). The bend radius R was approximately 32 mm. The catheters entered the gel along a straight path 318 for approximately 1 inch, transitioned into a 180 degree bend, and exited the gel straight up for approximately 1 inch. Each catheter was mounted on a motorized test stand 320 (MARK-10®, model ESM 301). The test stand 320 pumped each catheter straight down at 330 mm per minute into the artificial urethra of the cast gel block while the insertion force was recorded. Each catheter and path was generously lubricated with KY jelly to minimize frictional forces. The force differentials associated with each test catheter successfully navigating the mechanically bent and tortuous path were measured and compared. All samples were run through the test apparatus at least three times. The measurements were averaged to compare each design. The insertion force versus insertion depth test results for each design were compared as shown in FIG. 31B. Testing was performed on a 2x scale device (both test and control devices). The devices were fabricated with a 3D printer using similar rubber materials of comparable durometer and flexibility.

[0163] The data in FIG. 31B represents the force (compression) felt by a user (e.g., doctor, nurse, lab technician, etc.) when inserting, advancing, or otherwise pushing the proximal end of the catheter into a patient's lumen. That is, the force measurements are at the proximal end of the catheter that is being pushed. As shown in FIG. 31B, the standard of care Foley catheter and the Coud® catheter had the highest insertion forces compared to Test Catheter 1 and Test Catheter 2. Test Catheter 1 is the catheter shown in FIGS. 25A-25B (labeled "Duckbill" in FIG. 31B), and Test Catheter 2 was described in conjunction with FIGS. 28A-28C (labeled "OG Folde" in FIG. 31B).

[0164] As shown in FIG. 31B, the insertion force required for test catheters 1 and 2 to successfully navigate the tortuous simulated urethra is significantly less than that required for standard of care Foley and Coude® catheters. The insertion force required for the test embodiments to successfully navigate the curve in the model (entering the curve at approximately 50 mm insertion and exiting the curve at approximately 110 mm insertion) was significantly improved compared to the standard of care embodiment. Test catheter 1 peaked at approximately 0.65 N, test catheter 2 peaked at approximately 0.50 N, Foley catheter peaked at approximately 1.57 N, and Coude® catheter peaked at approximately 0.88 N. Based on these data, and generally, any of the embodiments described herein (e.g., the embodiments shown in FIGS. 6A-27B) that include one or more flexible regions may be configured such that the maximum insertion force required to insert the catheter into a body lumen is less than approximately 0.75 N. In some embodiments, the maximum insertion force may be less than about 0.70 N, less than about 0.60 N, less than about 0.55 N, or between about 0.40 N and about 0.80 N, between about 0.45 N and about 0.75 N, between about 0.5 N and about 0.80 N, and the like.

[0165] 32-34 show another exemplary test setup and resulting data for determining the bending force required for various flexible catheters described elsewhere herein. In other words, the test setup shown in FIG. 32 is configured to measure bending force for a radius. Although a few exemplary embodiments were tested, one of ordinary skill in the art will appreciate that other catheters described herein that include similar flexible regions may behave similarly to those shown. As shown in FIG. 32, each catheter 320 is constrained proximally by a block 360, and a normal load (indenter) 340 pushes against the catheter 320 (applying a force F to the catheter 320). The distal end 362 of the block 360 was located a first distance D1 (approximately 3.5 inches (88.9 mm)) from the distal tip 322 of the catheter 320, and the vertical load 340 was located a second distance D2 (approximately 2.5 inches (63.5 mm)) from the distal end 362 of the block 360, the distance measured from the central axis 342 of the vertical load 340. The catheter 320 was bent along a curved surface 380 with a radius 382 of approximately 1 inch (25.4 mm). The speed of the vertical load 340 was 100 mm per minute and was applied by a motor-driven test stand (MARK-10®, model ESM 301). The force F was measured by a MARK-10® force gauge, model M3-2.

[0166] FIG. 33 shows a graphical representation of force (N) versus deflection (mm) for various catheters deflected from 0 to 15 mm, with higher numbers indicating greater resistance to bending. For a standard of care Foley catheter, the deflection force increased approximately linearly with time, with the maximum force required to deflect 15 mm being approximately 0.16 N. In comparison, catheters with rear or front flex regions (here illustrated as the five regions also described with respect to FIGS. 28A-28C, or illustrated as region 152a in FIGS. 15A-15D) required a maximum force of approximately 0.069 N (when the grooves were "cut" upwards) or 0.052 N (when the grooves were "cut" downwards) to deflect 15 mm.

[0167] FIG. 34 shows a graphical representation of the force (N) required to deflect the illustrated catheter 15 mm. As shown in FIG. 34, a standard of care Foley catheter was tested and compared to two test catheters, one with multiple rear internal flexible regions and one with multiple front internal flexible regions. Exemplary embodiments of catheters with internal flexible regions are shown in FIGS. 20A-20G and 21A-21B. For the standard of care Foley catheter, the deflection force required to deflect the catheter 15 mm was 0.159 N. In comparison, the maximum force required for catheters with rear or front internal flexible regions was 0.145 N when the internal flexible region was located in the front, and 0.136 N when the internal flexible region was located in the rear.

[0168] To show the rigor of the simulated and test device data and to compare the data from the simulated and test devices, the data was normalized with respect to insertion force (y-axis) and insertion distance (x-axis) as shown in FIG. 35. The y-axis was normalized with the maximum insertion force from the test device data and the simulated data. The x-axis was normalized with the catheter length. A maximum of 0.6 means that 60% of the catheter was inserted. As shown in FIG. 35, the standard of care Foley and Coude® catheters required significant force to insert into the device (both the actual device and the modeled device) whether tested in the simulation or the physical test device. In comparison, the test catheter (labeled Ford, as shown and described in FIGS. 28A-28C) required significantly less force to insert. The test catheters required, on average, approximately 58% less force to insert than either the Foley or Coude® catheters.

[0169] In the specification and claims, the singular forms "a," "an," and "the" include both singular and plural references unless the context clearly contradicts. For example, the term "flexible region" can and is intended to include a plurality of flexible regions. At times, the claims and disclosure may include the phrases "a plurality," "one or more," or "at least one," but the absence of such words does not mean that a plurality is not contemplated and should not be interpreted to mean so.

[0170] The words "about" or "approximately," when used before a numerical designation or range (e.g., defining a length or pressure), indicate approximations that may vary by ±5%, ±1%, or ±0.1%. All numerical ranges given herein are inclusive of the beginning and ending values ​​stated. The word "substantially" refers to almost all (i.e., greater than 50%) or substantially all of a device, material, or composition.

[0171] As used herein, the words "comprising" or "comprises" shall mean that the devices, systems, and methods include the recited elements and may further include any other elements. "Consisting essentially of" shall mean that the devices, systems, and methods include the recited elements and exclude other elements that have an essential significance to the combination for the purposes of the description. Thus, a system or method consisting essentially of the elements defined herein will not exclude other materials, features, or steps that do not materially affect the basic and novel characteristics of the claimed disclosure. "Consisting of" shall mean that the devices, systems, and methods include the recited elements and exclude all or more insignificant or insignificant elements or steps. Embodiments defined by each of these transitional terms are within the scope of this disclosure.

[0172] The examples and specific examples contained herein are illustrative, not limiting, of specific embodiments in which the subject matter may be practiced. Other embodiments may be utilized or derived therefrom, such that structural or logical substitutions or changes may be made without departing from the scope of the present disclosure. Such embodiments of the subject matter may be referred to individually herein or collectively under the term "the present invention," which is merely for convenience and is not intended to spontaneously limit the scope of the present application to any one invention or inventive concept, even if more than one is actually disclosed. Thus, although specific embodiments have been shown and described herein, the specific embodiments shown may be substituted with any configuration designed to achieve the same purpose. The present disclosure encompasses any adaptations or variations of the various embodiments. Combinations of the above-described embodiments, as well as other embodiments not specifically described herein, will become apparent to those skilled in the art upon review of the above description.

Claims

Claim 1. An elongate body having a proximal segment and a distal segment, a lumen defined by the elongate body, at least one anterior flexible region on or within the distal segment of the elongate body, the at least one anterior flexible region extends into a first lumen from an outer anterior surface of the elongate body, extends at least partially circumferentially along the outer sidewall of the elongate body from the outer anterior surface of the elongate body without penetrating the first lumen along the outer sidewall, has a cut depth percentage of about 40% to about 50% of the outer diameter of the elongate body, and the percent volume of the removed material is about 20% to about 40%, the at least one anterior flexible region, A catheter comprising. Claim 2. The catheter according to claim 1, wherein the force to bend the at least one anterior flexible region is less than the force to bend a portion of the elongate body that does not include the at least one anterior flexible region. Claim 3. The catheter according to claim 1, wherein the force to bend the distal segment forward is less than the force to bend the distal segment backward. Claim 4. The catheter, a retention balloon disposed around at least a portion of the distal segment of the elongate body, a second lumen defined by the elongate body and configured to inflate the retention balloon, is a urinary catheter having, The catheter according to claim 1. Claim 5. The catheter according to claim 1, wherein the cut length percentage of the at least one anterior flexible region is about 10% to about 90%. Claim 6. The distal tip of the distal segment is tapered such that the ratio of the outer diameter of the elongate body to the outer thickness of the protrusion at the distal tip of the distal segment is about 1.0:0.8 to about 1.0:0.

2. The catheter according to claim 1. Claim 7. The at least one anterior flexible region includes a plurality of anterior flexible regions on or within the distal segment such that a second cut depth percentage of the most distal flexible region among the plurality of anterior flexible regions is greater than the cut depth percentage of the at least one anterior flexible region. The catheter according to claim 1. **Claim 8**: The catheter according to claim 7, wherein the most distal forwardly flexible region extends from a second region of the forward outer surface of the elongated body, around the inner sidewall of the first lumen, to the inner surface of the rear sidewall of the elongated body. **Claim 9**: The catheter according to claim 8, wherein the second cut depth percentage of the most distal forwardly flexible region is from about 60% to about 95% of the outer diameter of the elongated body. **Claim 10**: The catheter according to claim 1, further comprising at least one rearwardly flexible region on or within the distal segment. **Claim 11**: The catheter according to claim 10, wherein the at least one rearwardly flexible region includes a groove in the rear portion of the inner sidewall of the first lumen of the elongated body. **Claim 12**: The catheter according to claim 11, wherein the rear cut depth percentage of the groove in the rear portion of the inner sidewall of the first lumen is from 5% to about 20% of the wall thickness of the elongated body. **Claim 13**: An elongated body having a proximal segment and a distal segment, a lumen defined by the elongated body, at least one forwardly flexible region on or within the distal segment of the elongated body, wherein the at least one forwardly flexible region extends through the rear outer sidewall of the elongated body, around the inner sidewall of the lumen, and into the inner surface of the rear sidewall of the elongated body, has a cut depth percentage from about 80% to about 95% of the outer diameter of the elongated body, and has a percent volume of removed material from about 20% to about 40%, where the removed material is from the forward outer sidewall, the inner sidewall of the lumen, and the inner surface of the rear sidewall, the at least one forwardly flexible region, comprising a catheter. **Claim 14**: The catheter according to claim 13, wherein the cut length percentage of the at least one forwardly flexible region is from about 10% to about 90%. **Claim 15**: The catheter according to claim 13, wherein the distal tip of the distal segment is tapered such that the ratio of the outer diameter of the elongated body to the outer thickness of the protrusion at the distal tip of the distal segment is from about 1.0:0.8 to about 1.0:0.

2. **Claim 16**: An elongate body having a proximal segment and a distal segment, wherein the ratio of the outer diameter of the elongate body to the outer thickness of the protrusion at the distal tip of the distal segment is from about 1.0:0.8 to about 1.0:0.2, and the distal tip of the distal segment is tapered, the elongate body; a lumen defined by the elongate body; a plurality of anterior flexible regions located above or in the middle of the anterior side of the distal segment of the elongate body, at least one of the plurality of anterior flexible regions extends into the lumen from a first region of the outer surface of the posterior part of the elongate body, extends at least partially circumferentially along the first outer side wall of the elongate body from the first region of the outer surface of the posterior part, and the percentage volume of the removed material is from about 20% to about 40%, the plurality of anterior flexible regions; A catheter comprising. **Claim 17**: A second anterior flexible region of the plurality of anterior flexible regions, passes through a second region of the outer surface of the posterior part of the elongate body, surrounds the inner side wall of the lumen, and extends into the inner surface of the posterior side wall of the elongate body, the cut depth percentage is from about 80% to about 95% of the outer diameter of the elongate body, the percentage volume of the removed material is from about 20% to about 40%, the second anterior flexible region, The catheter according to claim 16, comprising. **Claim 18**: The catheter according to claim 16, further comprising a plurality of posterior flexible regions located above or in the distal segment, each of the plurality of posterior flexible regions being arranged transversely to each anterior flexible region of the plurality of anterior flexible regions. **Claim 19**: The catheter according to claim 18, wherein each of the plurality of posterior flexible regions has a posterior groove on the inner side wall of the lumen, and the cut depth percentage is from about 5% to about 20% of the outer diameter of the elongate body.

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