Technical Field

[0001] This disclosure relates generally to the guided removal of debris following a medical procedure. More specifically, but not by way of limitation, this disclosure relates to a steerable device configured to irrigate an area and to apply suction to that same area to fluidize debris and remove it.

Background

[0002] Kidney stones are a common medical problem that negatively impacts millions of individuals worldwide. Kidney stones include one or more solid masses of material that are usually made of crystals and form in parts of the urinary tract including in the ureter, the kidney, and/or the bladder of the individual. Kidney stones range in size from smaller (less than about 1 cm) to very large (more than 4 cm) and may cause significant pain to the individual and damage to the kidney. The overwhelming majority of stones that are treated by surgeons are less than 1 cm.

[0003] The recommended treatment for removal of the kidney stones varies according to numerous factors including the size of the kidney stones, the number of kidney stones, and the location of the kidney stones. The most common treatments for kidney stones are shock wave lithotripsy (ultrasound waves used to fracture the stones), ureteroscopy (fracture and removal of the stones using an endoscope that is introduced through the bladder), and percutaneous nephrolithotomy (fracture and removal of the stones using an endoscope that is introduced through a sheath placed through the patient's back into the kidney).

[0004] The largest kidney stones are usually removed through percutaneous nephrolithotomy or nephrolithotripsy, or through other similar procedures. In these procedures, a small incision is made through the patient's back adjacent the kidney and a sheath is passed into the kidney to accommodate a larger endoscope used to fracture and remove stones. The stone may be removed directly through the tube or may be broken up into small fragments while still in the patient's body and then removed via a vacuum or other known methods (nephrolithotripsy).

[0005] There are numerous drawbacks associated with nephrolithotomy, nephrolithotripsy, and other invasive surgeries requiring an incision in the skin. Namely, such surgical techniques may require significantly more anesthesia administered to the patient, the surgeries are more complicated and pose a higher risk of infection and complications for the patient, and the surgeries require a substantial incision in the patient, which may leave a scar. Additionally, given the invasiveness of the procedure, percutaneous procedures are usually not preferred for smaller kidney stones (e.g., less than 1 cm) depending on the size and location of the stones.

[0006] In contrast, traditionally, smaller kidney stones have been treated using other, less invasive techniques including through ureteroscopy. In ureteroscopy, the surgeon typically inserts a ureteroscope into the urethra through the bladder and the ureter to provide the surgeon with a direct visualization of the kidney stones which may reside in the ureter or kidney. The surgeon then removes the kidney stone directly using a basketing device if the kidney stone is small enough to pass through the urinary tract without difficulty, or the surgeon fractures the kidney stone into smaller pieces using a laser or other breaking device. After breaking the kidney stone into smaller pieces, the surgeon removes the laser or breaking device and inserts a basket or other object to capture the kidney stone fragments under the direct visualization of the ureteroscope. Upon retrieving some of the kidney stone fragments, the surgeon removes the basket from the patient and empties the kidney stone fragments therefrom. This process is repeated until clinically significant kidney stones and kidney stone fragments are broken up and removed from the body.

[0007] It should be apparent that this process is extremely time consuming, costly, and inefficient because the surgeon is required to insert and remove the scope and basket into and out of the patient many times to completely remove the kidney stones and kidney stone fragments therefrom. Using a basket removal device to capture kidney stones or kidney stone fragments suffers from other drawbacks in that the basket is difficult to position adjacent the kidney stone fragments and maneuver in a manner that effectively retrieves the fragments. The training required for such a procedure is not insignificant and the basket removal technique can be difficult for even the most skilled surgeons. Additionally, the surgeon is susceptible to hand fatigue due to the extended amount of time required to operate the kidney stone retrieval baskets. Further, the patient is required to be under local anesthesia and/or remain immobile over an extended amount of time. Still further, the basket retrieval devices cause irritation to the urinary tract due to the repeated insertion and removal therefrom.

[0008] Thus, there is an unmet need for new and improved devices and methods that permit minimally invasive removal of kidney stones.

Summary

[0009] An aspiration catheter system capable of removing kidney stone fragments through a combination of irrigation and aspiration is disclosed. The aspiration catheter system includes an aspiration catheter having a control handle with fluid-tight connections defining an irrigation path and airtight connections defining a vacuum path. The aspiration catheter is steerable and includes a self-straightening mechanism for enhancing safety.

[0010] An aspiration catheter for removal of kidney stones from a patient can include an elongate catheter shaft. A distal portion of the catheter shaft is steerable in one or more directions and the distal portion includes an aspiration port and an irrigation port. A vacuum shaft defining a vacuum lumen within the catheter shaft is in fluid communication with the aspiration port. An irrigation jacket defining the outer wall of an irrigation lumen within the catheter shaft is in fluid communication with the irrigation port. A deflection wire runs from a proximal portion of the catheter shaft to the distal portion of the catheter shaft and back to the proximal portion such that pulling on the deflection wire steers the distal portion by causing the distal portion to bend in one or more directions.

[0011] A method of manufacture of an aspiration catheter includes providing an elongate tubular structure for use as a vacuum shaft defining a vacuum lumen and aligning a deflection wire longitudinally along a first side of the elongate tubular structure such that a first portion of the deflection wire runs from a proximal portion of the elongate tubular structure to a distal portion of the elongate tubular structure and a second portion of the deflection wire runs from the distal portion of the elongate tubular structure back to the proximal portion of the elongate tubular structure. A loop portion of the deflection wire is attached to the distal portion of the elongate tubular structure and the loop portion located between the first portion of the deflection wire and the second portion of the deflection wire. A proximal portion of the first portion of the deflection wire and a proximal portion of the second portion of the deflection wire is attached to a steering control, and the steering control is configured to pull the first portion of the deflection wire and the second portion of the deflection wire to steer the aspiration catheter. [0012] An aspiration catheter for removal of kidney stones from a patient includes an elongate catheter shaft and a distal portion of the catheter shaft is steerable in one or more directions. The distal portion of the catheter shaft includes an aspiration port and an irrigation port. The elongate catheter shaft includes a vacuum shaft defining a vacuum lumen within the catheter shaft and in fluid communication with the aspiration port and an irrigation jacket defining the outer wall of an irrigation lumen within the catheter shaft and in fluid communication with the irrigation port. A wire braid section is integrated with a polymer jacket at a distal portion of the vacuum shaft.

[0013] An aspiration catheter for removal of kidney stones from a patient can include an elongate catheter shaft. A distal portion of the catheter shaft is steerable in one or more directions and the distal portion includes an aspiration port and an irrigation port. The catheter shaft includes a vacuum shaft including at least one vacuum lumen in fluid communication with the aspiration port. The catheter shaft also includes at least one irrigation lumen in fluid communication with the irrigation port. At least two deflection wires run from a proximal portion of the catheter shaft to the distal portion of the catheter shaft such that pulling on the deflection wires steers the distal portion by causing the distal portion to bend in one or more directions. The distal portion bends in a lateral plane defined by the deflection wires and bending out of the lateral plane is inhibited by stiffeners.

Brief Description of the Figures

[0014] Features, aspects, and advantages of the present disclosure are better understood when the following Detailed Description is read with reference to the accompanying drawings.

[0015] FIG. 1 illustrates one view of an aspiration catheter system according to certain aspects of the disclosure. [0016] FIG. 2 illustrates a close-up view of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0017] FIG. 3 illustrates another close-up view of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0018] FIG. 4 illustrates one view of a proximal portion of an aspiration catheter according to certain aspects of the disclosure.

[0019] FIG. 5 illustrates another view of a proximal portion of an aspiration catheter according to certain aspects of the disclosure.

[0020] FIG. 6 illustrates still another view of a proximal portion of an aspiration catheter according to certain aspects of the disclosure.

[0021] FIG. 7 illustrates a close-up view of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0022] FIG. 8 illustrates a close-up view of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0023] FIG. 9 illustrates a close-up, perspective view of the assembly of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0024] FIG. 10 is a close-up, sectional view of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0025] FIG. 11 is a sectional, perspective view of a proximal portion of an aspiration catheter according to certain aspects of the disclosure. [0026] FIG. 12 is a close-up, sectional view of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0027] FIG. 13 is a close-up view of the assembly of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure.

[0028] FIG. 14 is a perspective view of a portion of a steering control dial according to certain aspects of the disclosure.

[0029] FIG. 15 illustrates a close-up, plan view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0030] FIG. 16 illustrates a close-up, plan view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0031] FIG. 17 illustrates a close-up, end view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0032] FIG. 18 illustrates a close-up, plan view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0033] FIG. 19 illustrates a close-up, end view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0034] FIGs. 20A, 20B, 20C, 20D, and 20E illustrate close-up, perspective views of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure.

[0035] FIG. 21 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. [0036] FIG. 22 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0037] FIG. 23 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0038] FIG. 24 illustrates a block diagram of steps in a method of forming a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0039] FIG. 25 illustrates a close-up, plan view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0040] FIG. 26 illustrates a close-up, end view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0041] FIG. 27 illustrates a close-up, perspective view of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure.

[0042] FIG. 28 illustrates a close-up, plan view of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure.

[0043] FIG. 29 illustrates a close-up, plan view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0044] FIG. 30A illustrates a close-up, plan view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

[0045] FIG. 30B illustrates a close-up, plan view of a portion of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. [0046] FIG. 30C illustrates a close-up, plan view of a portion of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure.

Detailed Description

[0047] It is understood that this disclosure, in many respects, is only illustrative of the various alternative device examples of the present invention. Changes may be made in the details, particularly in matters of shape, size, material, and arrangement of various device components without exceeding the scope of the various examples of the invention.

[0048] When a feature or element is herein referred to as being “connected,” “attached,” or “coupled” to another feature or element, it can be directly connected, attached, or coupled to the other feature or element or intervening features or elements may be present. Although described or shown with respect to one example, the features and elements so described or shown can apply to other examples. It will also be appreciated by those of skill in the art that references to a structure or feature that is disposed “adjacent” another feature may have portions that overlap or underlie the adjacent feature.

[0049] Terminology used herein is for the purpose of describing particular examples only and is not intended to be limiting of the invention. For example, as used herein, the singular forms “a”, “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms “comprises” and/or “comprising,” when used in this specification, specify the presence of stated features, steps, operations, elements, and/or components, but do not preclude the presence or addition of one or more other features, steps, operations, elements, components, and/or groups thereof. As used herein, the term “and/or” includes any and all combinations of one or more of the associated listed items. [0050] The spatially relative terms, “proximal,” “distal,” and the like, may be used herein for ease of description to describe one element’s or feature's relationship to another. It will be understood that proximal describes a spatial location closer to the user or the intended position of the user while distal describe a location farther from the user or the intended position of the user. Further, when used with respect to a minimally invasive device like a catheter, proximal and distal locations refer to the portion of the device that is intended to be closer to or farther from the user, respectively, and do not change when the device is in use.

[0051] Although the terms “first” and “second” may be used herein to describe various features/elements (including steps), these features/elements should not be limited by these terms, unless the context indicates otherwise. These terms may be used to distinguish one feature/element from another feature/element. Thus, a first feature/element discussed herein could be termed a second feature/element, and similarly, a second feature/element discussed herein could be termed a first feature/element without departing from the teachings of the present invention.

[0052] As used herein in the specification and claims, including as used in the examples and unless otherwise expressly specified, all numbers may be read as if prefaced by the word “about” or “approximately,” even if the term does not expressly appear. The phrase “about” or “approximately” may be used when describing magnitude and/or position to indicate that the value and/or position described is within a reasonable expected range of values and/or positions.

[0053] Disclosed herein are systems, devices, and methods for the guided removal of objects in vivo. In particular, the systems, devices, and methods may be adapted to traverse compact areas, such as the urinary tract, and to remove debris, such as kidney stones or fragments of kidney stones, via aspiration through a vacuum tube. As used herein, the term “kidney stones” may refer to fragments of kidney stones, including fragments that have been created by therapeutic fracturing of kidney stones, such as with the device described herein or by another device. The term “kidney stones” may refer to stone or fragments of stones located in the ureter as well as in the kidney and the systems, devices, and methods disclosed herein may be capable of removing kidney stones from the kidney or ureter.

[0054] FIG. 1 illustrates one view of an aspiration catheter system according to certain aspects of the disclosure. The system includes an aspiration catheter 10 and an introducer 20. The aspiration catheter 10 includes a control handle 30 connected with a steerable distal shaft 50 by a flexible catheter shaft 15. The introducer 20 includes an introducer handle 40 at the proximal end and an introducer distal tip 60 at the distal end. The introducer 20 is configured to be slidable within a central lumen of the aspiration catheter 10. The introducer distal tip 60 is relatively soft and configured to be atraumatic to tissue. The introducer distal tip 60 can be inserted into the proximal end of the control handle 30 and the introducer 20 slid in the distal direction within the central lumen of the aspiration catheter 10 until the introducer distal tip 60 emerges from the distal end of the steerable distal shaft 50 of the aspiration catheter 10. The introducer handle 40 is configured to prevent the proximal end of the introducer 20 from sliding completely into the control handle 30. The introducer 20 is somewhat longer than the aspiration catheter 10. When the introducer handle 40 is snug against the control handle 30, the introducer distal tip 60 is at a desired position just beyond the distal end of the steerable distal shaft 50.

[0055] FIG. 2 illustrates a close-up view of a distal portion of an aspiration catheter according to certain aspects of the disclosure. FIG. 2 depicts the steerable distal shaft 50 in a curved orientation that is achievable using the steering system of the aspiration catheter as disclosed herein. The steerable distal shaft 50 is configured to be steerable to an extent that the distal -most portion of the steerable distal shaft 50 can be oriented at approximately 180 degrees from the orientation of the proximal-most portion of the flexible catheter shaft 15. [0056] FIG. 3 illustrates another close-up view of a distal portion of an aspiration catheter according to certain aspects of the disclosure. The steerable distal shaft 50 includes the distal portions of a vacuum lumen 70 and an irrigation lumen 80. Both the vacuum lumen 70 and the irrigation lumen 80 extend from the steerable distal shaft, through the flexible catheter shaft 15, and into the control handle 30. FIG. 3 illustrates that the vacuum lumen 70 and the irrigation lumen 80 are arranged coaxially such that the vacuum lumen 70 is encompassed by the irrigation lumen 80. The irrigation lumen 80 has a generally annular cross-section and the vacuum lumen 70 has a generally circular cross-section. A vacuum shaft 72 defines the vacuum lumen 70 and extends from the distal end of the steerable distal shaft 50 and into the control handle 30.

[0057] FIG. 4 illustrates one view of the proximal portion, FIG. 5 illustrates another view of the proximal portion, and FIG. 6 illustrates still another view of the proximal portion of an aspiration catheter according to certain aspects of the disclosure. At the proximal end of the control handle 30 is a vacuum port 31, which is configured to be attachable to tubing coming from a vacuum source, such as a vacuum pump or house vacuum. The vacuum port 31 includes a fitting that enables an airtight connection with the tubing from the vacuum source. FIG. 4,

FIG. 5, and FIG. 6 illustrate a vacuum controller 33 present on only one side of the control handle 30. The vacuum controller 33 can be any suitable mechanism for applying the suction generated at the vacuum port 31 to the vacuum lumen 70. One example of a suitable mechanism is an activatable valve. Another example of a vacuum controller is described in more detail herein with respect to FIG. 10. The vacuum port 31 and the vacuum controller 33 combine to provide control over the suction applied to the vacuum lumen 70 and thereby to the kidney stone fragments intended to be aspirated by the aspiration catheter system.

[0058] Referring still to FIG. 4, FIG. 5, and FIG. 6, the control handle 30 includes a steering control dial 35, which is connected to the steerable distal shaft 50 via a first deflection wire 13 and a second deflection wire 14 that each are present within the control handle 30 and the flexible catheter shaft 15. The control dial 35 is manipulable by a user’s hands and can contain tactile and/or visual features to indicate when the steerable distal shaft is in a neutral position.

For example, FIG. 4 and FIG. 5 illustrate that the control dial 35 can contain extended features

38 that define an axis at 90 degrees to the control handle 30 when the steerable distal shaft 50 is in a neutral position.

[0059] FIG. 4, FIG. 5, and FIG. 6 illustrate an irrigation port 37 present on only one side of the control handle 30. The irrigation port 37 is configured to be attachable to tubing coming from an irrigation source, such as a fluid pump or a syringe. The irrigation port 37 includes a fitting that enables a fluid-tight connection with the tubing from the irrigation source.

Optionally, the irrigation port 37 can include a mechanism for controlling the fluid flow rate and/or the flow rate can be controlled by the irrigation source.

[0060] FIG. 4, FIG. 5, and FIG. 6 illustrate a strain relief 39 in the area of the aspiration catheter where the flexible catheter shaft 15 is joined with the control handle 30. The strain relief

39 helps mitigate the flexibility mismatch between the relatively stiff control handle 30 and the flexible catheter shaft 15.

[0061] FIG. 4, FIG. 5, and FIG. 6 illustrate that the control handle 30 provides a user with convenient ways to control the aspiration, steering, and irrigation of a kidney during a procedure to remove kidney stone fragments. The control handle 30 is sized and configured to fit one hand of a user, who can manipulate one or more of the controls with one or both hands.

[0062] FIG. 7 and FIG. 8 illustrate a close-up view of a portion of a handle of an aspiration catheter with the control dial 35 in different positions. FIG. 7 and FIG. 8 illustrate that the control dial 35 is configured to rotate in both a clockwise and a counterclockwise direction. Rotation of the control dial 35 in one rotational direction steers the steerable distal shaft in a first direction while rotation of the control dial 35 in the opposite direction steers the steerable distal shaft in a second direction opposite the first direction.

[0063] In some aspects of the disclosure, the handle can include steering controls having other rotatable configurations. For example, the handle can include a control dial with a single user-controlled feature rather than the two extended features depicted in some examples herein. In another example, the handle can include a single lever coupled with or directly attached to a rotatable member such that moving the lever rotates the rotatable member. A control dial with a single extendable member is an example of this arrangement, but other arrangements are also possible. In some aspects, a single lever will travel in generally the same direction as the rotation of the rotatable member. In some aspects, the single user-controlled feature can be a mechanical slider that travels in line generally tangential to the rotation of the rotatable member.

[0064] FIG. 9 illustrates a close-up, perspective view of the assembly of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure. FIG. 10 is a close- up, sectional view of a portion of a handle of an aspiration catheter. The control handle 30 includes a control handle proximal section 32 and a control handle distal section 34. The control handle proximal section 32 includes the vacuum port 31 and the vacuum controller 33. The vacuum controller 33 is a port to the vacuum lumen molded within the control handle proximal section 32. The vacuum controller 33 is configured such that when it is uncovered the suction applied via the vacuum lumen draws air through the uncovered vacuum controller and no suction is applied through the length of the vacuum lumen to the distal end of the aspiration catheter. That is, when the vacuum controller 33 is uncovered there is essentially no suction at the distal end of the aspiration catheter. When the vacuum controller 33 is covered, suction is applied to the vacuum lumen and aspiration of kidney stone fragments is possible. [0065] FIG. 9 and FIG. 10 illustrate that the control handle distal section 34 includes the proximal portion of the vacuum shaft 72 in a molded channel within the control handle distal section 34. When the control handle 30 is assembled, the control handle proximal section 32 must form an airtight connection with the proximal portion of the vacuum shaft 72 to minimize any loss of suction. A proximal O-ring 36 is present between the outer surface of the proximal portion of the vacuum shaft 72 and the inner surface of the vacuum lumen molded within the control handle proximal section 32. The proximal O-ring 36 creates the airtight connection between the control handle proximal section 32 and the control handle distal section 34.

[0066] The proximal O-ring 36 enables a multi-part design for the control handle 30, which enables a reduction in the complexity of each component of the control handle. The control handle proximal section 32 can be formed by molding a part to include: (i) a main vacuum path from the distal end of the control handle proximal section 32 to the proximal end of the control handle proximal section 32 where the vacuum port 31 is located; and (ii) a branch vacuum path leading to the vacuum controller 33.

[0067] FIG. 11 is a sectional, perspective view of a proximal portion of an aspiration catheter and FIG. 12 is a close-up, sectional view of a portion of the same handle according to certain aspects of the disclosure. FIG. 11 illustrates the vacuum port 31, the vacuum controller 33, the proximal O-ring 36, and the vacuum shaft 72 in the control handle proximal section 32 as arranged in the description of FIG. 9 and FIG. 10. FIG. 11 also illustrates a distal O-ring 82 that helps define the fluid path through the irrigation lumen 80 present in the flexible catheter shaft 15 to the irrigation port 37 in the control handle distal section 34. The control handle distal section 34 can be formed to have a molded path for holding the proximal section of the flexible catheter shaft 15. The irrigation lumen 80 in the flexible catheter shaft 15 terminates at a location in the control handle distal section 34 that is distal of the irrigation port 37. The distal O-ring 82 forms a fluid-tight seal between the outer surface of the vacuum shaft 72 and the inner surface of the molded path for holding the proximal section of the flexible catheter shaft 15. The area within the molded path for holding the proximal section of the flexible catheter shaft 15 that is distal of the terminus of the irrigation lumen 80 can be bonded to the control handle distal section 34 with adhesive to form a fluid-tight seal.

[0068] The proximal O-ring 36 and the distal O-ring 82 enable the dual-lumen flexible catheter shaft 15 to be joined with the control handle 30 in a manner that eliminates substantial fluid leakage from the irrigation lumen 80 and transmits the suction force applied to the vacuum port 31.

[0069] FIG. 13 is a close-up view of the assembly of a portion of a handle of an aspiration catheter according to certain aspects of the disclosure and FIG. 14 is a perspective view of a portion of a steering control dial. FIG. 13 illustrates part of the control handle distal portion and shows the vacuum shaft 72 emerging from the proximal end of the control handle distal portion. FIG. 13 further illustrates one way that the first deflection wire 13 and the second deflection wire 14 are attached to the steering control dial 35 via a first proximal wire mount 16 and a second proximal wire mount 17. The first deflection wire 13 and the second deflection wire 14 exit the flexible catheter shaft and are wrapped around a post and secured at a mount. The first deflection wire 13 wraps around the first post 18 and is secured with the first proximal wire mount 16. Similarly, the second deflection wire 14 wraps around the second post 19 and is secured with the first proximal wire mount 17. FIG. 14 illustrates that the steering control dial 35 is formed of two identical halves that fit together when one half is rotated 180 degrees with respect to the other half.

[0070] FIG. 13 provides details about the role of the steering control dial 35 in deflecting the steerable distal shaft. As disclosed herein, the first deflection wire 13 and the second deflection wire 14 run from the steering control dial 35 and into the flexible catheter shaft, terminating within the steerable distal shaft. When the steering control dial 35 is rotated clockwise (as viewed from the perspective of FIG. 13), the second post 19 and the second proximal wire mount 17 also rotate clockwise and pull the second deflection wire 14, which is fixed in the distal end of the steerable distal shaft. Because the second deflection wire 14 is inelastic and of a fixed length, the steerable distal shaft is deflected in the same direction as the rotation of the steering control dial 35. At the same time, the first post 18 and the first proximal wire mount 16 also rotate clockwise and allow the first deflection wire 13 to move distally in the flexible catheter shaft because the first deflection wire 13 is also inelastic and of a fixed length.

[0071] The aspiration catheter disclosed herein includes a self-straightening feature that facilitates safe operation of the device. Structurally, the kidney includes major and minor calyces into which the aspiration catheter is steered to aspirate the kidney stone fragments located in such calyces. As disclosed herein the steerable distal shaft can take on a deflected configuration when steered and if the aspiration catheter is moved from one calyx to another with the aspiration catheter in a deflected configuration, damage may occur to kidney tissue. The self straightening feature of the aspiration catheter helps ensure that the steerable distal shaft returns to a neutral position where the risk of damage to tissue during catheter movement is minimized.

[0072] The self-straightening feature of the aspiration catheter relies on a balance of forces among the first deflection wire, the second deflection wire, and the steerable distal shaft. The first deflection wire and the second deflection wire are substantially identical such that when they are routed in and fixed in the handle the forces between each are balanced. The steerable distal shaft is formed from an inner polymer jacket, a metal braid, and an outer polymer jacket. The relative flexibility of the steerable distal shaft is determined by a combination of the inherent flexibility of the polymer and the metal used and the structural configuration of the material (the structural configuration is generally the thickness and shape of the part formed from the material). To achieve self-straightening, the relative flexibility of the steerable distal shaft must also be accounted for. That is, the force balance between the two deflection wires should not be greater than the straightening force of the steerable distal shaft. And the frictional forces on the wires as they slide along the flexible catheter shaft or within the control handle should not be greater than the straightening force of the steerable distal shaft. Finally, the sum of the force balance and the frictional forces should not be greater than the straightening force of the steerable distal shaft.

[0073] For some users, the aspiration catheter system disclosed herein is easier and more intuitive to use in kidney stone procedures than known devices for ureteroscopy, such as steerable ureteroscopes. Known steerable ureteroscopes are typically held out of plane with respect to the kidney, even to the extent of being held in a plane orthogonal to the major plane of the kidney. In contrast, the aspiration catheter system disclosed herein is configured to be held substantially in the same plane as the major plane of the kidney. In this way, controlling the deflection of the steerable distal shaft with the steering control dial is more intuitive than a conventional steerable ureteroscope. As disclosed herein, a clockwise rotation of the steering control dial causes a clockwise deflection of the steerable distal shaft. This steering relationship and the configuration of use in-plane with the kidney creates an ease of orientation and steering that is particularly valuable when the aspiration catheter is used without a visualization method.

It can be advantageous to perform aspiration of kidney fragments without a visualization method to maximize the amount of space in a device lumen available to remove kidney fragments (a ureteroscope takes up space in a device lumen) and/or to minimize radiation exposure to the patient and physician (in the case of fluoroscopy being used). Still further, the in-plane steering configuration of the aspiration catheter facilitates torque transmission along the length of the catheter. That is, by keeping the handle substantially in the same plane as the steerable distal shaft, torque on the handle is more easily transmitted to the steerable distal shaft as compared to a conventional steerable ureteroscope.

[0074] For some users, their familiarity of ureteroscopes may create a preference for a system with a handle held out of plane as with the known ureteroscope. The aspiration catheter system disclosed herein can be configured to be held in the conventional position of a ureteroscope such that it is out of plane with the distal section when that section is in the urinary tract. The steering controls can be arranged on the handle to provide one or more levers or extended features that couple with the rotatable member in the handle to move the pull wire or pull wires connected with the distal section in order to bend that distal section. Thus, the steering configurations disclosed herein can be adapted to a variety of steering orientations with respect to the distal section of the aspiration catheter.

[0075] One or more deflection wires can be used to control the steering or articulation of the steerable portion of the catheter. In some aspects, the deflection wire or wires can have a diameter in the range of from about 0.001 inch to about 0.005 inch. In some aspects, the deflection wire or wires can have a circular cross-section and preferably the deflection wire or wires comprise a multistrand cable. In some aspects, the deflection wire is a single multistrand cable that runs from the proximal portion of the catheter to distal portion of the catheter and back from the distal portion of the catheter to the proximal portion of the catheter.

[0076] FIGs. 15, 16, 17, 18, and 19 illustrate aspects of a subassembly of the aspiration catheter disclosed herein. The steerable shaft of the aspiration catheter includes tubular structures that define the vacuum lumen and the irrigation lumen. The vacuum lumen and the irrigation lumen are arranged coaxially such that the vacuum lumen is encompassed by the irrigation lumen. The irrigation lumen has a generally annular cross-section, and the vacuum lumen has a generally circular cross-section. The vacuum shaft defines the vacuum lumen, and an irrigation jacket defines the outer wall of the irrigation lumen. In FIGs. 15, 16, 17, 18, and 19 the irrigation jacket is not pictured and only a vacuum shaft subassembly including the various parts disclosed below is pictured.

[0077] In some aspects of the disclosure, the steerable shaft of the aspiration catheter includes tubular structures that define more than one vacuum lumen and one irrigation lumen, one vacuum lumen and more than one irrigation lumen, or more than one vacuum lumen and more than one irrigation lumen. In some aspects, the vacuum lumen and the irrigation lumen can be arranged to be generally colinear (as compared to arranged coaxially), and such colinear arrangements are also possible for the steerable shafts having more than one vacuum lumen or more than one irrigation lumen. For example, the steerable shaft of the aspiration catheter can include tubular structures that define one vacuum lumen and more than one irrigation lumen, and all of these lumens can be arranged to be generally colinear.

[0078] FIG. 15 illustrates a close-up, side view of a distal portion 150 of a subassembly of an aspiration catheter according to certain aspects of the disclosure. The distal portion 150 of the catheter includes a distal portion of a vacuum shaft 172 and a single deflection wire that is identified in FIG. 15 as including a first portion 113a, a second portion 113b, and a loop portion 113c. For avoidance of doubt, while the single deflection wire is identified as having various portions, it is a continuous structure formed from a single wire. The deflection wire first portion 113a and the deflection wire second portion 113b are positioned parallel to each other and running longitudinally along the length of the vacuum shaft 172.

[0079] FIG. 16 illustrates a close-up, side view of a distal portion 150 of a subassembly of an aspiration catheter according to certain aspects of the disclosure. The deflection wire loop portion 113c has been affixed to the distal end of the distal portion 150 of the vacuum shaft 172. The deflection wire loop portion 113c can be affixed to the vacuum shaft 172 through conventional methods, such as by adhesive bonding, heat bonding, mechanical interference, or combinations thereof. In some cases, the deflection wire loop portion 113c is affixed to the vacuum shaft 172 through the application and heating of a heat shrink material.

[0080] Once it is attached at or near the distal end of the vacuum shaft 172, the deflection wire loop portion 113c acts as an anchor point for the deflection wire to cause the deflection and steering of the steerable aspiration catheter. In prior art devices, pull wires are typically attached to a pull ring or other structure formed in or coupled to the catheter. There are several disadvantages with this prior art arrangement. For example, a ring or other structure often adds stiffness and/or reduces flexibility in the distal portion of the catheter. In another example, attaching pull wires to the ring or other structure requires an attachment step, such as laser welding or other bonding process. This attachment step adds time and complexity to the assembly process and inspection process, as well as creating a potential source of device failure. The single deflection wire attached to the distal end of the vacuum shaft avoids these disadvantages.

[0081] FIG. 17 illustrates a close-up, end view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. The deflection wire first portion 113a and the deflection wire second portion 113b are arranged on opposite sides of the vacuum shaft 172, which defines the vacuum lumen 170. However, the deflection wire first portion 113a and the deflection wire second portion 113b can be arranged in other ways with respect to the cross-section of the vacuum shaft 172. That is, if the arrangement of the deflection wire first portion 113a and the deflection wire second portion 113b on opposite sides of the vacuum shaft places them at 180 degrees about the cross-section of the vacuum shaft 172 from each other, then the deflection wire first portion 113a and the deflection wire second portion 113b can be arranged at radial angles from about 30 degrees to about 180 degrees from each other.

[0082] FIG. 17 illustrates that the deflection wire loop portion 113c illustrated in FIGs. 15 and 16 forms a semi-circle at or near the distal end of the of the vacuum shaft 172 without occluding the vacuum lumen 170. In examples of a vacuum shaft subassembly where the deflection wire first portion 113a and the deflection wire second portion 113b are arranged at radial angles from about 30 degrees to about 180 degrees from each other, the deflection wire loop portion 113c can be formed as a partial circular segment.

[0083] FIG. 18 illustrates a close-up, side view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. The distal portion 150 of the catheter includes a distal portion of a vacuum shaft 172 and a single deflection wire that is identified in FIG. 18 as including a first portion 113a, a second portion 113b, and a loop portion 113c. The deflection wire first portion 113a and the deflection wire second portion 113b are positioned parallel to each other and running longitudinally along the length of the vacuum shaft 172. In this example, the loop portion 113c includes a second loop, which provides for more wire to be attached at or near the distal end of the vacuum shaft 172.

[0084] FIG. 19 illustrates that the deflection wire loop portion 113c illustrated in FIG. 18 forms a circle at or near the distal end of the of the vacuum shaft 172 without occluding the vacuum lumen 170. In examples of the vacuum shaft subassembly where the deflection wire first portion 113a and the deflection wire second portion 113b are arranged at radial angles from about 30 degrees to about 180 degrees from each other, the deflection wire loop portion 113c can be formed as a partial circular segment or a full circle. [0085] FIGs. 20A, 20B, 20C, 20D, and 20E illustrate close-up, perspective views of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure. The deflection wire or wires of the aspiration catheter are connected to the vacuum shaft subassembly and/or the steering control mechanism near an end of the deflection wire or wires. FIGs. 20A, 20B, 20C, 20D, and 20E illustrate an end of a deflection wire 113 that includes a deflection wire terminal 114. The deflection wire terminal 114 allows for the deflection wire 113 to be anchored within the handle or distal portion of the catheter in a reliable and repeatable way. The deflection wire terminal 114 can be attached to the deflection wire 113 by crimping, by welding (including by laser welding), by soldering, or by any other equivalent method. In other aspects of the disclosure, thermal staking or an equivalent process is used to anchor an end of the deflection wire to the handle or distal portion of the catheter. A controlled flow of molten plastic is used to capture the deflection wire and fix it in place when the plastic cools. This thermal stake spreads the forces of the connection more evenly than other types of mechanical fixation, such as screwing a wire into place.

[0086] Referring now to another aspect of the manufacture of an aspiration catheter, the vacuum lumen 70 can be formed by an inner tube and the irrigation lumen 80 can be formed by an outer tube surrounding the inner tube. The inner tube can have an outer liner, an inner liner, and a wire braid. In some embodiments, the outer liner can comprise PEBAX®, nylon, and/or other plastics. In some embodiments, higher durometer regions (e.g., more proximal regions) can comprise nylon and lower durometer regions (e.g., more distal regions) can comprise PEBAX. The inner liner can comprise PEBAX, PTFE, polypropylene, polyurethane, nylon, polyimide, and/or other plastics. The wire braid can be encapsulated within the outer and inner liners. [0087] The catheter can comprise a plurality of tubes through which the pull wires extend. The tubes can comprise PTFE. The catheter can comprise a plurality of tubes extending through the wire braid, wherein the pull wires extend through the tubes.

[0088] FIG. 21 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. A distal portion 150 of a subassembly of an aspiration catheter can comprise a tubular wire braid 174 placed around a vacuum shaft 172. The braid 174 can help preserve the structural integrity of the aspiration catheter in general, and the distal portion 150 in particular in the steerable/articulating section (e.g., prevent kinking and/or collapsing of the vacuum lumen) and/or can help tailor the flexibility/rigidity of the distal potion 150. The braid 174 extends only a partial length of the distal potion 150.

[0089] The wire braid 174 can have a length of from about 1.0 cm to about 8.0 cm, and in some cases is preferably about 6.0 cm. The wire braid 174 can have an inner diameter of about 0.125 inches and be formed from a wire having a diameter of about 0.002 inches. The wire can be at least a 16 carrier, 24 carrier, 28 carrier, or 32 carrier braid. In some cases, the wire is preferably a 32 carrier braid. The braid is preferably about 100 ppi and is braided 2 over and 2 under. In other embodiments, other densities from about 60 ppi to about 200 ppi can be used and the wire can be braided in other configurations, such as 1 over 2 under 2 or 2 over 1.

[0090] The braid 174 can comprise a metal wire, such as a wire formed of a cobalt alloy.

One such cobalt alloy wire is available from Elgiloy of Sycamore, IL. It is a non-magnetic Cobalt-Chromium-Nickel-Molybdenum alloy having a unique combination of very high strength, excellent corrosion resistance, and high fatigue strength. Its nominal composition is Co: 39.0 - 41.0; Cr: 19.0 - 21.0; Ni: 14.0 - 16.0; Mo: 6.0 - 8.0; Mn: 1.5 - 2.5; Fe: balance; Si: 1.2 max; C: 0.15 max; Be: 0.1 max; P: 0.015 max; and S: 0.015 max. It has the certain advantageous physical properties, such as a modulus of elasticity at 20 degrees Celsius of up to 190 GPa, a modulus of rigidity at 20 degrees Celsius of 77.2 GPa, and a coefficient of expansion of 15.2 pm/m-deg C (20 degrees Celsius to 300 degrees Celsius).

[0091] The properties of the cobalt alloy braid 174 can be improved for use in the catheter as compared to the as-received material by a heat treatment step. The heat treatment step uses both time and temperature to improve the cobalt alloy braid 174. The time of the heat treatment can be in the range of from about 10 minutes to about 300 minutes, and preferably is in the range of from about 10 minutes to about 60 minutes. In some cases, the heat treatment time is about 30 minutes. The temperature of the heat treatment can be in the range of from about 200 degrees Celsius to about 1200 degrees Celsius, and preferably is in the range of from about 400 degrees Celsius to about 600 degrees Celsius. In some cases, the heat treatment temperature is about 525 degrees Celsius.

[0092] One disadvantage of using a tubular wire braid in a catheter subassembly is the tedious and time-consuming nature of trimming the braid to the correct length on the subassembly. The known methods of assembling a braided catheter subassembly typically require an assembler to manually trim the several individual wires that make up the braid. In this disclosure, an improved method for assembling a braided catheter subassembly is presented.

[0093] FIG. 22 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. A distal portion 150 of a subassembly of an aspiration catheter can include a tubular wire braid 174 placed around a vacuum shaft 172. The braid 174 must be secured in place on the distal portion 150 and polymer jacket 176 can be placed over the braid 174 and the vacuum shaft 172. The polymer jacket 176 can be a sheet or similar structure that is wrapped around the braid 174 and the vacuum shaft 172, or the polymer jacket 176 can be a tube or similar structure that is slid over the braid 174 and the vacuum shaft 172.

[0094] The polymer jacket 176 is preferably formed of a medical grade polymer material with mechanical properties suitable for use on a flexible, steerable aspiration catheter. Thermoplastic elastomers are one class of suitable polymer materials, and within that class is the class of polyether block amides known under the trade names PEBAX and VESTAMID E.

These materials have desirable properties, such as: melting point in the range of 134 degrees Celsius to 174 degrees Celsius; density in the range of 1.00 g/cm ³ to 1.03 g/cm ³ ; Shore D hardness in the range of 25 to 72; flexural modulus in the range of 12 MPa to 513 MPa; tensile strength at break in the range of 32 MPa to 56 MPa; and elongation at break in the range of 300% to 750%. In one example, the polymer jacket is a tube formed from PEBAX material with Shore D hardness of 35 and has an outer diameter of 0.148 inches and a tube wall thickness of 0.006 inches.

[0095] The polymer jacket 176 can be heated after being positioned over the braid 174 to both secure the braid 174 in the correct location on the vacuum shaft 172 and to integrate the softened polymer with the wires of the braid. This integration facilitates an improved way of cutting the braid 174.

[0096] FIG. 23 illustrates a close-up, side view of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. The distal portion 150 has been heated such that the tubular polymer jacket 176 conforms to the braid 174. The distal portion 150 has been cut in a single step that removes the furthest distal ends of the vacuum shaft 172, braid 174, and polymer jacket 176. This is an improved method as compared to known methods of creating a braided tip on a catheter. [0097] FIG. 24 illustrates a block diagram of steps in a method 200 of forming a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. In one step 210 of the method 200, the braid and polymer jacket are heat treated to make their respective mechanical properties more suitable for the subassembly manufacturing process and/or for use in the final aspiration catheter. In the case of the braid, a kiln is allowed stabilize at the desired temperature (from about 400 degrees Celsius to about 600 degrees Celsius), and preferably 525 degrees Celsius. The braid can be heat treated in the kiln for a length of time from about 10 minutes to about 60 minutes, and preferably about 30 minutes.

Ater the desired heat treatment time is elapsed, the braid is removed from the kiln, immediately quenched in room temperature water, and then allowed to dry at room temperature. The polymer jacket is also heat treated using an oven set to a temperature in the range of from about 30 degrees Celsius to about 120 degrees Celsius, and preferably about 60 degrees Celsius. The polymer jacket is heat treated in the oven for a length of time from about 10 minutes to about 120 minutes, and preferably for about 30 minutes.

[0098] FIG. 24 illustrates another step 220 in the method 200 of forming a subassembly of a distal portion of an aspiration catheter in which the braid and/or the polymer jacket are cut into segments suitable for the subassembly manufacturing process. In some aspects of the process, the braid and/or the polymer jacket are cut into segments prior to the heat treatment and in other aspects the braid and/or the polymer jacket are cut into segments after the heat treatment.

[0099] FIG. 24 illustrates another step 230 in the method 200 of forming a subassembly of a distal portion of an aspiration catheter in which the braid is positioned on the vacuum shaft at the desired location. A tubular braid can be slid onto the vacuum shaft and affixed to the vacuum shaft with an intermediary such as a thin heat shrink material, or the tubular braid can be held in position in a fixture. In some aspects, the braid can be stretched in proximal to distal direction as part of the step 230 of positioning the braid on the vacuum shaft.

[0100] FIG. 24 illustrates another step 240 in the method 200 of forming a subassembly of a distal portion of an aspiration catheter in which the polymer jacket is positioned on the braid at the desired location. A tubular polymer jacket can be slid onto the vacuum shaft and braid and affixed to the vacuum shaft with an intermediary such as a thin heat shrink material, or the tubular polymer can be held in position in a fixture.

[0101] FIG. 24 illustrates another step 250 in the method 200 of forming a subassembly of a distal portion of an aspiration catheter in which the polymer jacket is heated at a temperature that integrates the polymer jacket with the braid. The polymer jacket can be heated at a temperature in the range of from about 200 degrees Celsius to about 500 degrees Celsius, and preferably at about 400 degrees Celsius. The length of the heating can be from less than a minute to several minutes.

[0102] FIG. 24 illustrates another step 260 in the method 200 of forming a subassembly of a distal portion of an aspiration catheter in which the composite structure formed by integrating the polymer jacket with the braid is cut. Advantageously as compared to prior art methods, the polymer jacket and braid can be cut as a unit, which substantially decreases the time and labor required to form the distal portion of the vacuum shaft subassembly.

[0103] FIG. 25 illustrates a close-up, side view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. The distal portion 150 of the catheter includes a tubular wire braid 174 placed around a distal portion of a vacuum shaft 172. The braid 174 may be secured in place on the distal portion 150 by the methods disclosed herein or by any other method that provides a secure connection, such as by adhesive bonding, heat bonding, mechanical interference, or combinations thereof. A first deflection wire 181 and a second deflection wire 183 are positioned parallel to each other and run longitudinally along the length of the vacuum shaft 172. The first deflection wire 181 and the second deflection wire 183 terminate along the distal portion 150 of the catheter and may be attached to the braid 174, the vacuum shaft 172, or both by the methods disclosed herein of by any other method that provides a secure connection, such as by adhesive bonding, heat bonding, mechanical interference, or combinations thereof.

[0104] The first deflection wire 181 and the second deflection wire 183 attached at the distal portion 150 provide anchor points to cause the deflection and steering of the steerable aspiration catheter via the steering control mechanism on the handle. However, if the forces of the deflection wires are not properly balanced, the distal portion 150 may be steered out of the plane defined by the rest of the vacuum shaft. That is, the distal portion 150 may not simply steer laterally with respect to its neutral position but may also steer vertically with respect to its neutral position.

[0105] In some aspects of the disclosure, it is convenient to refer to lateral and vertical directions of bending such that the lateral directions of bending are in the plane defined by the deflection wires running along the sides of the aspiration catheter. The vertical direction is orthogonal to the lateral direction. The additional vertical direction of movement may be undesirable. And eliminating this additional vertical direction of movement by closely balancing all the forces on the deflection wires can add time and effort to the assembly process.

[0106] In some aspects of the disclosure, the irrigation lumen has a generally annular cross- section, and the vacuum lumen has a generally circular cross-section, and this arrangement of these two lumens will typically result in isotropic mechanical properties with respect to the common cross-section of the lumens. In other words, in this arrangement the aspiration catheter system bends with essentially the same resistance to bending in all radial directions about the center of the lumen cross-sections. Thus, the aspiration catheter will bend equally easily in all directions.

[0107] In some aspects of the disclosure, the irrigation lumen or lumens and the aspiration lumen or lumens are arranged such that one or more of them is offset with respect to the center of the overall cross-section of the aspiration catheter. Lumens may be side by side, for example, or one lumen may be offset within another lumen. In these arrangements of lumens, the mechanical properties of the aspiration catheter may be anisotropic with respect to the center of the overall cross-section of the aspiration catheter. That is, the aspiration catheter system bends with less resistance to bending in some radial directions about the center of the overall cross- section of the aspiration catheter and with more resistance to bending in other radial directions about the center of the overall cross-section of the aspiration catheter. The aspiration catheter will not bend equally easy in all directions.

[0108] FIG. 25 illustrates the use of subassembly braid stiffener 175 to reduce, minimize, or eliminate an undesirable vertical direction of movement. The braid stiffener 175 is a wire or ribbon attached to some or all of the length of the braid 174 at a position on the braid approximately midway between the first deflection wire 181 and the second deflection wire 183. The braid stiffener 175 can help prevent vertical movement of the distal portion 150 even when the forces on the deflection wires are out of balance. In some aspects of the disclosure, multiple braid stiffeners can be attached to the braid to reduce, minimize, or eliminate an undesirable vertical direction of movement.

[0109] FIG. 26 illustrates a close-up, end view of another subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. FIG. 26 illustrates an arrangement of the first deflection wire 181, the second deflection wire 183, and two braid stiffeners 175 about the cross section of the vacuum shaft 172. From the end view of FIG. 26, the first deflection wire 181 and the second deflection wire 183 are seen to be arranged on opposite sides of the cross section of the vacuum shaft 172 such that they could be identified as being at a 0-degree position and a 180-degree position on the cross section of the vacuum shaft 172. Using these reference points, the two braid stiffeners 175 are at a 90-degree and a 270- degree position, respectively. This is one possible arrangement of the two braid stiffeners 175 to reduce, minimize, or eliminate an undesirable vertical direction of movement.

[0110] FIG. 26 also illustrates that the braid stiffeners can have a rectangular cross-section such that the long edge of the rectangular cross-section is aligned with the vertical direction of movement. In this configuration, the braid stiffener will more easily resist bending in the vertical direction while being comparatively easier to bend in the lateral dimension. In some aspects, the braid stiffener has a different asymmetric cross-section, such as an elliptical cross-section, and is arranged on the braid such that the braid stiffener resists bending in the vertical direction more than in the lateral direction.

[0111] FIGs. 27 and 28 illustrate different views of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure. A distal outer member 190 includes one or more distal outer member stiffeners 195. The distal outer member 190 and the distal outer member stiffener(s) are formed of polymeric materials. Suitable polymeric materials include, but are not limited to, PEBAX, PTFE, polypropylene, polyurethane, nylon, and/or other polymers. The distal outer member 190 can be formed of a polymeric material having an inherent stiffness and formed at a specific thickness such that the distal outer member 190 has a first amount of stiffness. That is, providing the first amount of stiffness to the distal outer member 190 can be accomplished by using a specific material at a desired thickness in one or more layers of the distal outer member 190. Suitable methods for forming the distal outer member 190 include extrusion.

[0112] In some aspects of the disclosure, the distal outer member stiffener 195 is formed of a polymeric material having an inherent stiffness and formed at a specific thickness such that the distal outer member stiffener 195 has a second amount of stiffness that is different from the first amount of stiffness of the distal outer member 190. The distal outer member stiffener 195 can be in the form of a stripe along the length of the distal outer member 190. Because the distal outer member stiffener 19 has a second amount of stiffness, it produces anisotropy in the bending flexibility of the distal outer member 190. FIG. 27 illustrates on aspect of the disclosure in which two identically shaped distal outer member stiffeners 195 are formed on opposite sides of the distal outer member 190. In this aspect, the distal outer member stiffeners 195 are like the braid stiffeners 175 in FIG. 26. Suitable methods for forming the distal outer member 190 having distal outer member stiffeners 195 include coextrusion.

[0113] FIG. 29 illustrates a view of a portion of a subassembly of an aspiration catheter according to certain aspects of the disclosure. In FIG. 29, the distal outer member 190 has been secured to the distal portion 150 by the methods disclosed herein or by any other method that provides a secure connection, such as by adhesive bonding, heat bonding, mechanical interference, or combinations thereof. A first deflection wire 181 and a second deflection wire 183 are positioned parallel to each other and run longitudinally along the length of the vacuum shaft 172. The first deflection wire 181 and the second deflection wire 183 terminate along the distal portion 150 of the catheter and may be attached to the distal outer member 190, the vacuum shaft 172, or both by the methods disclosed herein of by any other method that provides a secure connection, such as by adhesive bonding, heat bonding, mechanical interference, or combinations thereof. [0114] FIGs. 30A, 30B, and 30C illustrate close-up, plan views of a subassembly of a distal portion of an aspiration catheter according to certain aspects of the disclosure. FIG. 30A illustrates a distal outer member 190 that includes distal outer member slots 196. The distal outer member 190 is divided into portions having different flexibility, where the flexibility is determined by the number, shape, and spacing of the distal outer member slots 196. The portion of the distal outer member 190 near the proximal end P has distal outer member slots 196 that are spaced apart from each other by a distance that is less than the spacing of the distal outer member slots 196 in the portion of the distal outer member 190 near the distal end D. Because of this difference in spacing of the distal outer member slots 196, the portion of the distal outer member 190 near the proximal end P is less flexible than the portion of the distal outer member 190 near the distal end D. Similar differences in flexibility can be achieved by using wider slots versus narrower slots, where the wider slots would create a more flexible portion of the distal outer member 190 assuming the same center-to-center distance between the distal outer member slots 196 in each portion. Further, elliptical slots may create less flexibility than rectangular slots. The ends of the distal outer member slots 196 can include features to inhibit crack propagation and/or to provide strain relief when the distal outer member 190 is bent. In some aspects, these features may be rounded sections, single arcs, or double arcs at the ends of the slots.

[0115] FIG. 30B illustrates a magnified plan view of area B of the distal outer member 190. FIG. 30B shows a transition between one pattern of the distal outer member slots 196 that are spaced more closely than the pattern of the distal outer member slots 196 that is more proximal. FIG. 30C illustrate a similar type of transition in area C of the distal outer member 190.

[0116] In some aspects of the disclosure, the overall length of the distal outer member can be in the range of about 40 mm to about 80 mm, and preferably in the range of about 55 mm to about 65 mm. The proximal portion of the distal outer member, that is, the portion of the distal outer member beginning at its proximal end and extending to the proximal transition in flexibility, can have an overall length of from about 8 mm to about 25 mm, and preferably in the range of from about 12 mm to about 18 mm. The intermediate portion of the distal outer member, that is, the portion of the distal outer member beginning at the proximal transition in flexibility and extending to a distal transition in flexibility, can have an overall length of from about 8 mm to about 25 mm, and preferably in the range of from about 12 mm to about 18 mm. The distal portion of the distal outer member, that is, the portion of the distal outer member beginning at the distal transition in flexibility and extending to its distal end, can have an overall length of from about 16 mm to about 50 mm, and preferably in the range of from about 25 mm to about 35 mm. In some aspects of the disclosure, the distal outer member 190 illustrated in FIGs. 30A, 30B, and 30C is a hypotube formed of metal, polymer, or a composite of materials. The distal outer member slots 196 can be laser cut or otherwise machined into the hypotube.

[0117] In certain aspects of the disclosure, any anisotropy in the bending of the distal portion of the aspiration catheter can be mitigated by the braid stiffeners and/or distal outer member stiffeners. The bending anisotropy may be due to an imbalance in the forces delivered by the deflection wire or wires, the cross-section of the overall aspiration catheter as a result of the locations of lumens, or a combination of both. The braid stiffener and/or the distal outer member stiffener allows the deflection of the distal portion of the aspiration catheter to be tuned to eliminate undesirable deflection, such as in the vertical direction.

[0118] In one aspect of the disclosure, an aspiration catheter system includes a flexible introducer configured to be insertable within a central lumen of a steerable catheter. The steerable catheter includes an irrigation lumen and a vacuum lumen, wherein each lumen is coupled to a control handle such that there is a fluid-tight seal between the irrigation lumen and the control handle and an airtight seal between the vacuum lumen and the control handle. In some aspects of the disclosure, the steerable catheter includes a self-straightening mechanism.

[0119] In another aspect of the disclosure, each lumen is coupled to a control handle such that there is a fluid-tight seal between the irrigation lumen and the control handle and an airtight seal between the vacuum lumen and the control handle.

[0120] In another aspect of the disclosure, an aspiration catheter for removal of kidney stones from a patient includes an elongate catheter shaft such that a distal portion of the catheter shaft that is steerable in one or more directions. The distal portion includes an aspiration port and an irrigation port. The aspiration catheter also includes a vacuum shaft defining a vacuum lumen within the catheter shaft and in fluid communication with the aspiration port. The aspiration catheter also includes an irrigation jacket defining the outer wall of an irrigation lumen within the catheter shaft and in fluid communication with the irrigation port and a deflection wire running from a proximal portion of the catheter shaft to the distal portion of the catheter shaft and back to the proximal portion such that pulling on the deflection wire steers the distal portion by causing the distal portion to bend in one or more directions.

[0121] In another aspect of the disclosure, the aspiration catheter also includes a handle coupled to the catheter shaft and in fluid communication with the vacuum lumen and irrigation lumen. In some aspects of the disclosure, the handle includes one or more deflection levers attached to the deflection wire such that movement of the one or more deflection levers accomplishes the pulling of the deflection wire. In some aspects of the disclosure, the deflection wire comprises a first portion and a second portion, each of which runs longitudinally along the catheter shaft. In some aspects of the disclosure, the first portion of the deflection wire and the second portion of the deflection wire are on opposite sides of the catheter shaft from each other. In some aspects of the disclosure, the first portion of the deflection wire and the second portion of the deflection wire are arranged at a radial angle about the cross-section of the vacuum shaft of from about 30 degrees to about 180 degrees from each other. In some aspects of the disclosure, the deflection wire comprises a loop portion in between the first portion and second portion. In some aspects of the disclosure, the loop portion is attached to the distal portion of the catheter shaft. In some aspects of the disclosure, the loop portion is attached to a distal portion of the vacuum shaft. In some aspects of the disclosure, the loop portion forms a semi-circular shape when attached to the distal portion of the vacuum shaft. In some aspects of the disclosure, the loop portion forms a partial circular shape when attached to the distal portion of the vacuum shaft. In some aspects of the disclosure, the loop portion includes at least one full loop. In some aspects of the disclosure, the loop portion includes more than one full loop. In some aspects of the disclosure, the loop portion is attached to a distal portion of the vacuum shaft. In some aspects of the disclosure, the loop portion forms a circular shape when attached to the distal portion of the vacuum shaft. In some aspects of the disclosure, the vacuum shaft defines the inner wall of the irrigation lumen. In some aspects of the disclosure, the irrigation lumen has an annular shaped cross-section. In some aspects of the disclosure, the irrigation lumen has a partially annular shaped cross-section.

[0122] In another aspect of the disclosure, an aspiration catheter for removal of kidney stones from a patient is formed following a method of manufacture including certain steps. One step includes providing an elongate tubular structure for use as a vacuum shaft defining a vacuum lumen. Another step includes aligning a deflection wire longitudinally along a first side of the elongate tubular structure such that a first portion of the deflection wire runs from a proximal portion of the elongate tubular structure to a distal portion of the elongate tubular structure and a second portion of the deflection wire runs from the distal portion of the elongate tubular structure back to the proximal portion of the elongate tubular structure. Another step includes attaching a loop portion of the deflection wire to the distal portion of the elongate tubular structure, the loop portion located between the first portion of the deflection wire and the second portion of the deflection wire. Another step includes attaching a proximal portion of the first portion of the deflection wire and a proximal portion of the second portion of the deflection wire to a steering control, wherein the steering control is configured to pull the first portion of the deflection wire and the second portion of the deflection wire to steer the aspiration catheter.

[0123] In some aspects of the disclosure, the deflection wire is a multistrand cable. In some aspects of the disclosure, the loop portion comprises a single loop. In some aspects of the disclosure, the loop portion comprises a full circular loop. In some aspects of the disclosure, the loop portion comprises at least a full loop. In some aspects of the disclosure, the loop portion comprises multiple loops. In some aspects of the disclosure, the loop is attached to a distal end of the elongate tubular structure. In some aspects of the disclosure, the loop portion forms a semi-circular shape when attached to the distal portion of the elongate tubular structure. In some aspects of the disclosure, the loop portion forms a partial circular shape when attached to the distal portion of the elongate tubular structure. In some aspects of the disclosure, the loop portion forms a full circular shape when attached to the distal portion of the elongate tubular structure.

[0124] In another aspect of the disclosure, an aspiration catheter for removal of kidney stones from a patient includes an elongate catheter shaft and a distal portion of the catheter shaft that is steerable in one or more directions. The distal portion includes an aspiration port and an irrigation port. The aspiration catheter also includes a vacuum shaft defining a vacuum lumen within the catheter shaft and in fluid communication with the aspiration port. The aspiration catheter also includes an irrigation jacket defining the outer wall of an irrigation lumen within the catheter shaft and in fluid communication with the irrigation port. The aspiration catheter also includes a wire braid section integrated with a polymer jacket at a distal portion of the vacuum shaft.

[0125] In another aspect of the disclosure, the vacuum shaft defines the inner wall of the irrigation lumen. In some aspects of the disclosure, the irrigation lumen has an annular shaped cross-section. In some aspects of the disclosure, the irrigation lumen has a partially annular shaped cross-section. In some aspects of the disclosure, the vacuum shaft extends beyond a distal end of the irrigation jacket. In some aspects of the disclosure, at least some of the distal portion of the vacuum shaft that includes the wire braid section extends beyond the distal end of the irrigation jacket. In some aspects of the disclosure, the wire braid section extends to the distal end of the distal portion of the vacuum shaft. In some aspects of the disclosure, the wire braid section comprises a cobalt-chromium-nickel-molybdenum alloy. In some aspects of the disclosure, the wire braid section has been heat treated. In some aspects of the disclosure, the wire braid section has been heat treated for about 30 minutes in at temperature of about 525 degrees Celsius. In some aspects of the disclosure, the polymer jacket comprises a thermoplastic elastomer. In some aspects of the disclosure, the polymer jacket comprises a polyether block amide. In some aspects of the disclosure, the polymer jacket comprises PEBAX. In some aspects of the disclosure, the wire braid section is integrated with a polymer jacket via heating.

[0126] In another aspect of the disclosure, a subassembly for use in an aspiration catheter for removal of kidney stones from a patient is formed following a method of manufacture including certain steps. One step includes providing an elongate tubular structure for use as a vacuum shaft defining a vacuum lumen. Another step includes positioning a wire braid on a distal portion of the elongate tubular structure. Another step includes positioning a polymer jacket on the wire braid. Another step includes heating the polymer jacket at a temperature that integrates the polymer jacket with the braid to form a composite structure. Another step includes cutting the composite structure.

[0127] In some aspects of the disclosure, the wire braid is heat treated prior to being positioned on the elongate tubular structure. In some aspects of the disclosure, the wire braid is heat treated for 30 minutes at a temperature of 525 degrees Celsius. In some aspects of the disclosure, the wire braid is quenched in water after being heated. In some aspects of the disclosure, the polymer jacket is heat treated prior to being positioned on the wire braid. In some aspects of the disclosure, the polymer jacket is heat treated for 30 minutes at a temperature of 60 degrees Celsius prior to being positioned on the wire braid. In some aspects of the disclosure, the wire braid and/or the polymer jacket are cut to a desired length prior to heat treatment. In some aspects of the disclosure, the wire braid and/or the polymer jacket are cut to a desired length after heat treatment. In some aspects of the disclosure, the composite structure is formed by heating at a temperature of about 400 degrees Celsius. In some aspects of the disclosure, the composite structure and the elongate tubular structure are cut simultaneously.

[0128] While the present subject matter has been described in detail with respect to specific embodiments thereof, it will be appreciated that those skilled in the art, upon attaining an understanding of the foregoing, may readily produce alterations to, variations of, and equivalents to such embodiments. Any one of the above-described aspects can be used in combination with any other one or more aspects. Accordingly, it should be understood that the present disclosure has been presented for purposes of example rather than limitation, and does not preclude the inclusion of such modifications, variations, and/or additions to the present subject matter as would be readily apparent to one of ordinary skill in the art. Table of Reference Numerals