Internal Tubular Member for an Angled Rotary Surgical Instrument

Abstract

An internal member rotatable within an angled outer tubular member of a rotary surgical cutting instrument includes a first tubular member and a second tubular member. The first tubular member includes a rigid proximal portion and a rigid distal portion composed of a first material and a flexible intermediate portion composed of a second material. The proximal portion includes a hub. The distal portion terminates at a distal end configured to be coupled to a cutting tip. The intermediate portion extends between the proximal portion and the distal portion and is fixedly coupled to the proximal portion and the distal portion.

Description

[0001] This divisional application of a patent application for invention is a divisional application of the patent application for invention with the international application number PCT / US2016 / 029737, the international filing date of April 28, 2016, the application number entering the Chinese national phase of 201680030730.3, and the title of "Internal Tubular Member for an Angled Rotary Surgical Instrument". Background Art

[0002] Angled rotary tissue cutting instruments have been widely accepted for use in various surgical procedures to cut anatomical tissue at a surgical site within a patient's body. An angled rotary tissue cutting instrument typically includes an elongated angled outer member and an elongated flexible inner member rotatably disposed within the angled outer member. A cutting element at the distal end of the inner member is exposed from an opening at the distal end of the outer member to cut anatomical tissue at the surgical site as the inner member rotates within the outer member. The inner member is typically rotated within the outer member by an electric surgical handpiece coupled to the proximal ends of the outer member and the inner member, with the handpiece remaining external to the patient's body. The outer member has one or more angled, curved, or bent regions along its length to provide an angled configuration that facilitates positioning the cutting element at the surgical site when the instrument is introduced into the patient's body, and particularly when the instrument is introduced through a natural or artificially formed access opening of narrow or small size within the patient's body. The inner member is provided with one or more flexible regions to reside within one or more of the angled, curved, or bent regions of the outer member for transmitting torque to rotate the cutting element while conforming to the angled configuration of the outer member. The angled configuration of the outer member is particularly advantageous for facilitating the positioning of the cutting element at a surgical site where there is a non-linear path in the body forming an access opening to the surgical site. In such cases, angled rotary tissue cutting instruments are generally more suitable for easier and faster access to the surgical site and cause less trauma to the patient as compared to rotary tissue cutting instruments having a longitudinally straight outer member.

[0003] In many surgical procedures performed using a rotating tissue cutting instrument, an internal lumen of an internal member is used to convey suction to a surgical site to aspirate anatomical tissue and / or fluid through the internal member. Additionally, an annular clearance or clearance between an inner diameter of an outer member and an outer diameter of the internal member is typically used as a flushing passage for supplying a flushing fluid to the surgical site. Although rotating tissue cutting instruments having a curved or bendable shaft have been used for some time, these shafts typically employ a single helically wound strip of material to impart flexibility while transmitting torque. Unfortunately, helically wound shafts and couplings are prone to unwinding when rotated in a direction opposite their winding, such that torque can only be effectively transmitted in one direction. When the internal member is rotatably conformable to an angled configuration of the outer member while rotating, a flushing loss may occur due to a helical cut or coil of a clearance formed along a flexible region of the internal member. In many applications, a loss of flushing can be dangerous. For example, in a neuro-oncology resection device, microelectromechanical (MEM) components are often used, where a loss of flushing may cause the device to clog, resulting in failure. In other devices, such as in an ear, nose, and throat (ENT) microsweeper, the device may become less effective due to a loss of flushing caused by insufficient saline at the cutting tip.

[0004] Angled rotating tissue cutting instruments have been very useful. There is a need for an elongate tubular assembly that can maintain sufficient strength and stiffness while transmitting torque through a flexible region and prevent a loss of flushing, especially considering that angled rotating tissue cutting instruments must often be designed to operate at high rotational speeds and withstand forces applied when cutting hard or tough anatomical tissue. SUMMARY OF THE INVENTION

[0005] One aspect of the present disclosure relates to an internal member that is rotatable within an angled outer tubular member of a rotating surgical cutting instrument. The internal member includes a first tubular member. The first tubular member includes a rigid proximal portion composed of a first material. The proximal portion includes a hub. A flexible intermediate portion is composed of a second material. A rigid distal portion is composed of the first material. The distal portion terminates at a distal end configured to couple to a cutting tip. The flexible intermediate portion extends between the proximal portion and the distal portion and is fixedly coupled to the proximal portion and the distal portion.

[0006] Another aspect of the present disclosure relates to an internal member that is rotatable within an angled outer tubular member of a rotating surgical instrument. The internal member includes a first tubular member. The first tubular member has a proximal portion, a distal portion, and an intermediate portion extending between the proximal portion and the distal portion. The proximal portion and the distal portion are composed of a rigid material. The intermediate portion is composed of a flexible thermoplastic material.

[0007] Another aspect of the present disclosure relates to an angled rotary tissue cutting instrument that includes a rigid outer tubular member, an inner tubular member, and a handpiece. The rigid outer tubular member has a cutting window formed at a distal end, an opposite proximal end, and an angled region between the distal end and the proximal end. The inner tubular member is coaxially disposed within the outer tubular member. The inner tubular member includes a first tubular member. The first tubular member has a proximal portion, a distal portion terminating at a cutting tip, and an intermediate portion extending between the proximal portion and the distal portion. The intermediate portion is composed of a flexible material, and the proximal portion and the distal portion are composed of a rigid material. The handpiece is configured to rotate the inner member within the outer member to selectively expose the cutting tip at the cutting window. When rotated within the outer tubular member, the flexible region of the inner tubular member conforms to the angled region. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 is a perspective view of an angled rotary surgical cutting instrument in accordance with the principles of the present disclosure;

[0009] Figure 2 is in accordance with the principles of the present disclosure Figure 1 of a perspective view of the inner member of the surgical cutting instrument;

[0010] Figure 3 is in accordance with the principles of the present disclosure Figure 2 of the inner member assembly in an unbent configuration;

[0011] Figure 4 is in accordance with the principles of the present disclosure Figure 1 of a partial enlarged cross-sectional view of the blade assembly of the surgical cutting instrument at region A. DETAILED DESCRIPTION

[0012] One embodiment of a surgical cutting instrument 10 in accordance with the principles of the present disclosure is shown in Figure 1 . The surgical cutting instrument 10 includes a cutting blade assembly 12 and a handpiece 14 (generally referred to in Figure 1 ). Generally, the cutting blade assembly 12 has a proximal end connected to the handpiece 14 and a distal end terminating at a cutting tool 16. The cutting blade assembly 12 includes an elongate outer member 18 and an elongate inner member 20 extending between the proximal end and the distal end. The inner member 20 is coaxially disposed within the outer member 18. Optionally, the cutting blade assembly 12 may include an intermediate tubular member (not shown) coaxially disposed between the outer member 18 and the inner member 20.

[0013] The inner member 20 is coaxially disposed within the outer member 18 such that the cutting tip is exposed at the cutting window of the tool 16. The cutting window and the cutting tip (not shown) combine to form the tool 16 and can be any cutting window and cutting tip suitable for performing the desired procedure. The hub assembly 22 couples the outer member 18 and the inner member 20 to the handpiece 14, respectively, such that the tubular members 18, 20 are rotatable relative to each other and the handpiece 14. The cutting blade assembly 12 may have one or more curved, angled, or bent regions along its length. The terms curved, angled, or bent may be used interchangeably herein. The location and degree of the bend or bend are predetermined to appropriately accommodate the desired surgical procedure. More specifically, the outer member 18 rigidly defines the appropriate angle between the proximal end and the distal end.

[0014] Continuing to refer Figure 1 , the outer member 18 is an elongated tubular body defining a distal end, a proximal end, and a central lumen extending between the proximal end and the distal end. The central lumen generally defines a uniform diameter and is generally uniformly smooth. The inner member 20 is maintained within the central lumen of the outer member 18 such that the outer surface of the inner member 20 and the inner surface of the outer member 18 define a flushing channel leading to the tool 16 when assembled. The size of the central lumen of the outer member 18 is designed to coaxially receive the inner member 20 within the wall of the outer member 18 and maintain the flushing channel between the walls of the inner member 20 and the outer member 18.

[0015] Generally speaking, the handpiece 14 includes a housing that contains a motor (not shown) for driving the rotational movement of the inner member 20. The handpiece 14 receives the proximal ends of the inner member 20 and the outer member 18 for fluidly connecting the inner flushing and suction paths (each not shown) to the fluid channels assembled to the handpiece 14, respectively. In any case, the flushing path formed within the handpiece 14 extends through the outer member 18 to the cutting window. Similarly, the suction channel formed within the handpiece 14 fluidly extends through the inner member 20 to the cutting tip and is in fluid communication with a negative pressure source for applying negative pressure or vacuum to the suction path and thus to the inner member 20.

[0016] Given the above general construction of the surgical instrument 10, aspects of the inner member 20 of the cutting blade assembly 12 are shown in more detail in Figure 2 . The inner member 20 defines a lumen between an open proximal end and a distal end. The inner member 20 includes a first tubular member 24 and a second tubular member 26 coaxially disposed around the first tubular member 24. In some embodiments, as discussed in more detail below, the inner member 20 includes a third tubular member 28 coaxially disposed around the first tubular member 24 and the second tubular member 26.

[0017] In Figure 3 the exploded view of various aspects of the inner member 20 are shown. The first tubular member 24 includes a proximal portion 30, a distal portion 32, and an intermediate portion 34 extending between the proximal portion 30 and the distal portion 32. The proximal portion 30 and the distal portion 32 are formed of a rigid material such as stainless steel, for example. The intermediate portion 34 is formed of a flexible thermoplastic material such as

[0018] For additional reference Figure 4 to the partial exploded cross-sectional view of the opposite first end 36a and second end 36b of the intermediate portion 34 are coupled to the proximal portion 30 and the distal portion 32, respectively. The proximal portion 30 and the distal portion 32 may be fixedly fastened to the intermediate portion 34 with an adhesive such as

[0019] by induction bonding or by other bonding means. The proximal portion 30 and the distal portion 32 may include engagement ends 38, 40 for coupling to the intermediate portion 34. The engagement ends 38, 40 may have a smaller outer diameter or may be inserted from the outer diameters of the bodies 42, 44 of the proximal portion 30 and the distal portion 32, respectively. The outer diameters of the engagement ends 38, 40 closely correspond to the inner diameter of the intermediate portion 34 such that the engagement ends 38, 40 are slidably received within the intermediate portion 34. The engagement ends 38, 40 provide surfaces for coupling and bonding to the intermediate portion 34. The proximal portion 30 includes a hub 46 at the proximal end for connection to a handle of a surgical instrument (not shown). The distal end 48 of the distal portion 32 is adapted to be connected to a cutting tip (not shown) of appropriate nature to perform a desired procedure. The outer diameter of the intermediate portion 34 is substantially equal to the outer diameters of the proximal portion 30 and the distal portion 32 along the bodies 42, 44. The outer diameters of the bodies 42, 44 are substantially equal. When assembled, the outer diameter of the first tubular member 24 is substantially consistent along the proximal portion 30, the distal portion 32, and the intermediate portion 34, with only the hub 46 having a greater diameter. Figure 3Shown as linear in , but when the inner member 20 is coaxially disposed within the outer member 18, the intermediate portion 34 is flexible and configured to conform to the curved or angled regions of the outer member 18. The inner member 20 is coaxially disposed within the outer member 18 such that the intermediate portion 34 of the inner member 20 is positioned along the bent or curved portion of the outer member 18. The intermediate portion 34 can be bent at any desired angle. For example, the intermediate portion 34 can be bent 20°, 45°, 90°, 120°, or even greater than 120°. Other angles suitable for providing the desired application and procedure are also suitable. The intermediate portion 34 has a thickness sufficient to prevent kinking or breakage when rotating within the curved outer member 18.

[0020] Continuing reference Figures 2 to 4 , the second tubular member 26 includes opposite proximal section 50 and distal section 52, and a central section 54 extending between the proximal section 50 and the distal section 52. Although shown as linear in Figure 3 , the central section 54 includes a helical cut pattern to provide longitudinal flexibility along the central section 54. The helical cut extends through the thickness of the second tubular member 26 between the outer surface and the inner surface. The helical cut defines an angle with the central longitudinal axis of the second tubular member 26. The helical cut defines a flexible region along the length of the second tubular member 26. When the inner member 20 rotates within the bent or angled outer member 18 and conforms to the shape of the outer member, the central section 54 provides flexibility and torque transmission along the flexible region of the inner member 20.

[0021] When assembled with the first tubular member 24, the central section 54 is coaxially disposed around the flexible intermediate portion 34 of the first tubular member 24. In one embodiment, the length L2 of the central section 54 is slightly less than the length L1 of the intermediate portion 34. When coaxially disposed, the flexible helical cut central section 54 terminates along the flexible intermediate portion 54 between the first end 36a and the second end 36b. The proximal section 50 is coaxially disposed around the proximal portion 30 and fixed to the proximal portion 30, and the distal section 52 is coaxially disposed around the distal portion 32 and fixed to the distal portion 32. For example, the second tubular member 26 can be formed of a rigid material such as stainless steel. The terminals of the proximal section 50 and the distal section 52 can be fixedly fastened to the proximal portion 30 and the distal portion 32 respectively by laser welding or other suitable bonding means.

[0022] In some embodiments, a third tubular member 28 is included and coaxially disposed over the first tubular member 24 and the second tubular member 26. The third tubular member 28 is similar to the second tubular member 26 and includes opposite proximal section 60 and distal section 62, and a central section 64 extending between the proximal section 60 and the distal section 62. In one embodiment, the central section 64 includes a helical cut pattern to provide longitudinal flexibility along the central section 64. The helical cuts extend through the thickness of the third tubular member 28 between the outer surface and the inner surface. The helical cuts define an angle with the central longitudinal axis of the third tubular member 28 in a direction generally opposite to the angle of the helical cuts of the central section 54 of the second tubular member 26. For example, when a left-handed laser cut is provided on the second tubular member 26, a right-handed laser cut is provided on the third tubular member 28. The helical cuts define a flexible region along the length of the third tubular member 28. When assembled with the first tubular member 24 and the second tubular member 26, the central section 64 is coaxially disposed along the flexible intermediate portion 34 and the central section 54. When the inner member 20 rotates within the bent or angled outer member 18 and conforms to the shape of the outer member, the central section 54 provides flexibility and torque transmission along the flexible region of the first tubular member 24.

[0023] In one embodiment, the central section 64 has a length L3 that is less than the length L2 of the central section 54 and less than the length L1 of the intermediate portion. In any case, the total length of the second tubular member 26 is greater than the total length of the third tubular member 28 such that when coaxially disposed, the proximal section 60 is fixed to the proximal section 50 and the distal section 62 is fixed to the distal section 52. In one embodiment, for example, the third tubular member 28 is formed of a rigid material such as stainless steel. The terminals of the proximal section 60 and the distal section 62 may be fixedly fastened to the proximal section 50 and the distal section 52, respectively, by laser welding or other suitable bonding means.

[0024] In another embodiment, the third tubular member 28 is formed of a flexible plastic material. For example, the third tubular member 28 may be formed of a thermoplastic material such as polytetrafluoroethylene (PTFE) or fluorinated ethylene propylene (FEP). In this embodiment, the inner and outer surfaces of the third tubular member 28 are generally smooth and are not interrupted by grooves, cuts, etc. In this embodiment, when the inner tubular member 20 rotates within the outer tubular member 18, the third tubular member 28 reduces the coefficient of friction between the inner tubular member 20 and the outer tubular member 18. When assembled, the third tubular member 28 extends fully along the length of the central section 54 and terminates at the opposite proximal section 50 and distal section 52 of the second tubular member 26. The third tubular member 28 is fixedly fastened to the second tubular member 26 by induction bonding or other suitable means.

[0025] The inner member 20 without the third tubular member 28 is suitable for a surgical instrument that rotates in a single direction. The third tubular member 28 may desirably be included in, for example, a swinging surgical instrument. In an embodiment including the third tubular member 28 having a helical cutout central section 64, by including helical cutouts in opposite directions on the second tubular member 26 and the third tubular member 28, when rotating in a direction opposite to the helical cutout of the second tubular member 26 during swinging, an undesired unwinding of the central section 54 is prevented. In an embodiment including the third tubular member 28 formed of a thermoplastic, an undesired unwinding of the central section 54 is similarly prevented when rotating in a direction opposite to the helical cutout of the second tubular member 26 during swinging.

[0026] While the present disclosure has been described with reference to preferred embodiments, those skilled in the art recognize that changes may be made in form and detail without departing from the spirit and scope of the present disclosure.

Claims

1. An internal member rotatable within an angled outer tubular member of a rotary surgical cutting instrument, comprising: A first tubular member including a flexible intermediate portion axially disposed between a rigid distal portion and a rigid proximal portion, the distal and proximal portions being composed of a first material and the intermediate portion being composed of a second material different from the first material; and A second tubular member coaxially disposed around the first tubular member and having a flexible central section disposed between a rigid distal section and a rigid proximal section, the central section surrounding the flexible intermediate portion and allowing the first tubular member to bend while rotating relative to the outer tubular member, wherein the terminals of the proximal and distal sections are fixedly fastened to the proximal and distal portions respectively, wherein the proximal section is coaxially disposed around the proximal portion and fixedly fastened to the proximal portion, and the distal section is coaxially disposed around the distal portion and fixedly fastened to the distal portion.

2. The internal component according to claim 1, characterized in that, The distal section, the central section, and the proximal section of the second tubular member are composed of stainless steel.

3. The internal member according to claim 1, wherein, The second tubular member is fixedly attached to the proximal and distal portions of the first tubular member.

4. The internal component according to claim 1, wherein The flexible intermediate portion of the first tubular member is composed of a thermoplastic material, and the distal and proximal portions of the first tubular member are composed of stainless steel.

5. The internal component according to claim 1, wherein The first tubular member includes a substantially constant outer diameter along the distal portion, the intermediate portion, and the proximal portion.

6. The internal component according to claim 1, wherein, The length of the intermediate portion of the first tubular member is greater than the length of the central section of the second tubular member.

7. The internal member according to claim 1, wherein The central section includes a pattern of helical cuts extending through the thickness of the second tubular member between the outer surface and the inner surface.

8. The internal component according to claim 1, characterized in that, Further comprising a third tubular member coaxially disposed around the second tubular member, wherein the third tubular member includes a flexible central section, and wherein the flexible central section of the third tubular member is disposed over the central section of the second tubular member.

9. The internal member according to claim 8, wherein The second tubular member has a length greater than the length of the third tubular member.

10. The internal component according to claim 1, characterized in that, The outer tubular member includes a cutting blade disposed in a cutting window, and the rotary surgical cutting instrument includes a handpiece coupled to the internal member to rotate the internal member within the outer tubular member and selectively expose the cutting blade within the cutting window.

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