Patent Publication Number: US-2022218379-A1

Title: Surgical cutting tool

Description:
CROSS REFERENCE TO RELATED APPLICATION 
     This application claims priority of U.S. Provisional Patent Application No. 63/136,595, filed on Jan. 12, 2021, entitled SURGICAL CUTTING TOOL, the entire contents of which are hereby incorporated herein by reference. 
    
    
     BACKGROUND 
     The present disclosure relates to devices used in endoscopic surgery and, more particularly, to a tissue cutting tool with suction. 
     There is a need for a surgical cutting tool that remedies the shortcomings of prior art surgical cutting tools. 
     SUMMARY 
     The present disclosure relates to improved tissue cutting tools. A surgical cutting tool, according to an implementation has: a body with a proximal end and a distal end; a cannula rotatably extending from the distal end of the body, the cannula having a proximal end and a distal end; a cutting head removably coupled to the distal end of the cannula, the cutting head having a distal tip and a cutting window; a hollow shaft movably positioned inside the cannula, the hollow shaft having a blade; a suction connector in fluid communication with the hollow shaft, the suction connector being configured for connection to a suction source; a suction control configured to alter suction from the suction connector to the hollow shaft; and an actuator coupled to the hollow shaft for moving the blade of the hollow shaft relative to the cutting window of the cutting head. 
     In an implementation, the surgical cutting tool has a plurality of interchangeable cutting heads. Optionally, at least one of the plurality of interchangeable cutting heads has a rounded distal end. At least one of the plurality of interchangeable cutting heads may have a rounded distal end and a cutting window oriented at an angle pointing away from the rounded distal end. Optionally, at least one of the plurality of interchangeable cutting heads has an angled distal end. At least one of the plurality of interchangeable cutting heads may have an angled distal end and a cutting window oriented at an angle pointing toward the angled distal end. 
     Optionally, at least one of the plurality of interchangeable cutting heads has a flat distal end and a cutting window positioned proximal to the flat distal end. At least one of the plurality of interchangeable cutting heads may have an angled distal end that extends beyond a diameter of the cannula and a cutting window positioned proximal to the angled distal end. 
     In an implementation, the suction control is coupled to the body and movable between an open position to reduce suction through the hollow shaft and the cutting window and a closed position to increase suction through the hollow shaft and the cutting window. The suction control may have a crenelated surface. In an implementation, the body has a handle with a thumb loop; and the actuator has a finger loop. 
     In an additional implementation, a surgical cutting tool has a body with a distal end; a handle positioned proximal to the distal end; a suction connector, the suction connector being configured for connection to a suction source; a suction pathway extending from the suction connector through at least a portion of the body; and a control pathway in fluid communication with the suction pathway. A cannula rotatably extends from the distal end of the body, the cannula having a proximal end and a distal end. A cutting head is removably coupled to the distal end of the cannula, the cutting head having a distal tip and a cutting window. A hollow shaft is movably positioned inside the cannula, the hollow shaft having a blade. A suction control is slidably coupled to the body and configured to adjustably open the control pathway to alter suction from the suction connector to the hollow shaft. An actuator is rotatably coupled to the body and coupled to the hollow shaft for moving the blade of the hollow shaft relative to the cutting window of the cutting head. In an implementation, the handle has a thumb loop; the actuator has a finger loop; and the handle and actuator are operated as a scissors to move the shaft. 
     According to an implementation, the surgical cutting tool may be used by inserting the cannula into a patient to a desired surgical site; orienting the cutting window to the tissue to be cut; manipulating the actuator to move the shaft blade across the cutting window to sever tissue extending into the cutting window; and withdrawing the cannula from a patient. Optionally, prior to insertion, the suction control is moved to an open position to reduce suction through the hollow shaft and the cutting window. Optionally, after inserting the cannula into a patient, the suction control is moved to a closed position to increase suction through the hollow shaft and the cutting window to draw tissue into the cutting window. 
     These and other features are described below. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
       The features, aspects and advantages of the present invention will become better understood with regard to the following description, appended claims and accompanying figures wherein: 
         FIG. 1  is a side elevation view of a surgical cutting tool according to an implementation; 
         FIG. 2  is an exploded side elevation cross-sectional view of the surgical cutting tool of  FIG. 1 . 
         FIG. 3  is a perspective elevation view of a surgical cutting tool according to an implementation with a portion of the housing shown as semi-transparent; 
         FIG. 4  is a side elevation cross-sectional view of a surgical cutting tool according to an implementation; 
         FIG. 5  is a top view of a surgical cutting tool according to an implementation with a suction control in a open position; 
         FIG. 6  is a top view of a surgical cutting tool according to an implementation with a suction control in a closed position; 
         FIG. 7  is an enlarged view of a portion of a cannula, shaft and cutting head according to an implementation. 
         FIG. 8A  is a side elevation view of a cutting head for a surgical cutting tool according to an implementation. 
         FIG. 8B  is a perspective elevation view of the cutting head of  FIG. 8A . 
         FIG. 9A  is a side elevation view of a cutting head for a surgical cutting tool according to an additional implementation. 
         FIG. 9B  is a perspective elevation view of the cutting head of  FIG. 9A . 
         FIG. 10A  is a side elevation view of a cutting head for a surgical cutting tool according to an additional implementation; 
         FIG. 10B  is a perspective elevation view of the cutting head of  FIG. 10A ; 
         FIG. 11A  is a side elevation view of a cutting head for a surgical cutting tool according to an additional implementation; and 
         FIG. 11B  is a perspective elevation view of the cutting head of  FIG. 11A . 
     
    
    
     DETAILED DESCRIPTION 
     In the following description of the preferred implementations, reference is made to the accompanying drawings which show by way of illustration specific implementations in which the invention may be practiced. Wherever possible, the same reference numbers will be used throughout the drawings to refer to the same or like parts. It is to be understood that other implementations may be utilized and structural and functional changes may be made without departing from the scope of this disclosure. 
     With reference to  FIGS. 1 to 7 , a surgical cutting tool  10  according to an implementation has a body  12 . The body  12  has a proximal end  14  and a distal end  16 . A cannula  18  is coupled to the distal end  16  of the body  12 . The cannula  18  has a proximal end  20  and a distal end  22 . A cutting head  24  is coupled to the distal end  22  of the cannula  18 . The cannula  18  length may be varied depending on the desired application. In an implementation, the cannula  18  has a length of between about 50 mm and about 150 mm. In an implementation, the cannula  18  has a length of about 70 mm. In an implementation, the cannula  18  has a length of about 130 mm. 
     The body  12  has a handle  26 . In an implementation, the handle has a loop  28  for placement of a user&#39;s finger, such as a thumb. An actuator  30  is coupled to the body  12 . In an implementation, the actuator  30  has a loop  32  for placement of a user&#39;s finger, such as a forefinger. The actuator  30  is rotatably mounted to the housing such as by using a pin  34 . The thumb of a user may be placed in the handle loop  28  and the forefinger in the actuator loop  32  and the handle  26  and the actuator  30  manipulated as a scissors. Optionally, in an implementation, a spring is mounted between the handle  26  and the actuator  30  to maintain the actuator in a predetermined position relative to the handle. 
     The proximal end  20  of the cannula  18  is coupled to a rotating hub  36 . In an implementation, the rotating hub  36  is welded onto an outside surface of the cannula  18 . The body  12  is configured so that the rotating hub  36  fits inside of a hub opening. A pin  38  extends through the body  12  and rests in a groove  40  of the rotating hub  36  to prevent axial movement, but to allow rotation, of the hub and the cannula  18 . The groove  40  may extend entirely around the rotating hub  36  to allow for 360 degree rotation of the hub and the cannula  18 . Alternatively, the groove  40  may extend less than entirely around the rotating hub  36  if it is desired to limit rotation of the rotating hub and the cannula  18 . 
     The rotating hub  36  allows the cannula  18  to be rotated so the cutting head  24  orientation can change as explained in more detail below. In an implementation, the rotating hub  36  has a knob  42  to assist a user in rotating the cannula  18 . In an implementation, the knob  42  is crenelated or otherwise textured to assist a user in locating and turning the knob. 
     Positioned inside of the cannula  18  and extending into the body  12  is a hollow shaft  44 . The hollow shaft  44  has a blade  46  which cooperates with cutting head  24  as further explained below. The shaft  44  is coupled to the actuator  30 . In an implementation, a cross pin  48  is coupled to the shaft  44 . The cross pin  48  may be welded to the shaft  44 . The cross pin  48  rests in a groove  50  on the actuator  30 . As the actuator  30  is rotated relative to the body  12 , the groove  50  moves the cross pin  48  and with it the shaft  44 . The shaft  44  and the blade  46  may be made from stainless steel and the blade  46  may be made of a different material than the rest of the shaft. Additionally, the blade  46  may be removably attached to the shaft  44 . The shaft  44  moves linearly within the cannula  18  to cut tissue positioned in the cutting head  24  as explained in more detail below. 
     The body  12  also has a suction port  52  for connection of a suction source (not shown). The suction port may have a barb  54  or threads for retaining a suction source connector. In an implementation, the suction port  52  is positioned on the proximal end  14  of the body  12 . As shown in  FIG. 4 , the suction port  52  is in fluid communication with a suction pathway  56  through the body  12  and to the shaft  44 . Additionally, the suction port  52  is in fluid communication with a control pathway  58 . A suction control  60  is movably positioned on the body. 
     In an implementation, the suction control  60  is slidably movable between an open position and a closed position. In the open position, air may be pulled into the body  12  through the control pathway  58  rather than through the cutting head  24  and the shaft  44 . In the closed position, the suction pulls air in through cutting head  24  and the shaft  44 . The user may move the suction control  60  between the open and closed positions to vary the amount of suction at the cutting head  24 . The suction control  60  may be crenelated or otherwise textured to assist a user in locating and manipulated the suction control. 
     The cutting head  24  may be varied for different applications. In an implementation, the cutting head  24  is removably coupled to the distal end  22  of the cannula  18 , such as by mating threads. Alternatively, the surgical cutting tool  10  may be configured with a specific cutting head  24 . As shown in  FIG. 7 , the cutting head  34  has a cutting window  62  with a cutting edge  64 . As the shaft  44  is advanced through the cannula  18 , the blade  46  of the shaft passes along the cutting edge  64  and severs any tissue extending into the cutting window  62 . In an implementation, the blade  46  is circular so that the blade  46  can cut tissue regardless of the orientation of the cutting head  24  and the cutting window  62 . 
     Suction may assist in pulling tissue into the cutting window  62 . Additionally, suction may assist in removing cut tissue from the cutting window  62  by pulling the cut tissue back through the shaft  44 , through the suction pathway  56  and out through the suction port  52 . In an implementation, a tissue capture container is placed between the suction source and the suction port  52  to catch cut tissue. In an additional implementation, liquid or pressurized gas may be communicated into the suction port  52  and out through the cutting window  62 . 
     Cutting heads according to several implementations are described below. The implementations are intended to be illustrative and not restrictive. As shown in  FIGS. 8A and 8B , the cutting head  24 A, according to an implementation, may have a diameter of about 3 mm and may be formed with a rounded distal end  66 . The rounded distal end  66  may be helpful for pushing the surgical cutting tool  10  through tissue to reach a surgical site. Positioned proximal to the distal end  66  is a cutting window  68 . The cutting window  68  may be oriented at an angle pointing away from the distal end  66 . The cutting window has a distal wall and proximal wall separated by a flat central portion. In an implementation, the distal wall has an angle A of from about 40 degrees to about 70 degrees, and more preferably about 55 degrees. In an implementation, the proximal wall has an angle B of from about 30 degrees to about 60 degrees, and more preferably about 45 degrees. In an implementation, the cutting window  68  has a depth C of from about 0.03 inches to about 0.09 inches, and more preferably about 0.06 inches. In an implementation, the cutting window  68  has a length D of from about 0.05 inches to about 0.15 inches, and more preferably about 0.10 inches. 
     In use, cutting head  24 A operates like a hook and a user moves the distal end  66  past the tissue to be cut and then pulls the cutting head backward (with or without suction) to lead tissue into the cutting window  68 . The actuator  30  is then manipulated by the user to move the shaft  44  distally with the blade  46  of the shaft moving across the cutting window  68  to cut whatever tissue is in the cutting window. The cutting head  24 A may be useful for hand and wrist, ENT (ear, nose and throat), Spine and other arthroscopic surgery applications. The back biter distal tip design allows surgeons the ability to use standard portals and efficiently resect soft tissue such as the TFCC (triangular fibrocartilage complex) in a retrograde distal to proximal direction. 
     As shown in  FIGS. 9A and 9B , the cutting head  24 B may have a diameter A of about 3 mm and an angled distal end  70 . The angled distal end may have an undercut edge  71  with angle B of from about 0 degrees to about 15 degrees and more preferably about 6 degrees. The remainder of the angled distal end  70  may be at an angle C of from about 20 degrees to about 50 degrees and more preferably about 35 degrees. The angled distal end  70  may be helpful in lifting tissue or in maneuvering the cutting head  34 B between two closely positioned structures. 
     Positioned about 0.05 inches to about 0.15 inches, and more preferably about 0.11 inches proximal to the distal end  70  is a cutting window  72 . The cutting window  72  may be oriented at angle pointing toward the distal end  70 . In an implementation, the cutting window is oriented at an angle D of from about 35 degrees to about 65 degrees and more preferably about 50 degrees. The cutting window  72  has angled distal and proximal walls separated by a flat central portion. In an implementation, the flat central portion has a length E of from about 0.05 inches to about 0.15 inches, and more preferably about 0.10 inches. In an implementation, the distal wall and proximal wall are separated by a distance F of from about 0.04 inches to about 0.12 inches, and more preferably about 0.08 inches. 
     In use, cutting head  34 B operates like a scoop or sled and a user moves the distal end  70  to the tissue to be cut and then scoops the tissue into the cutting window  72  with or without suction. The actuator  30  is then manipulated by the user to move the shaft  44  distally with the blade  46  of the shaft moving across the cutting window  72  to cut whatever tissue is in the cutting window. The cutting head  24 B may be useful for knee surgery applications, such as for cutting and manipulating edges of meniscal tissue and other hard to reach flat tissue pathologies in various arthroscopic and endoscopic surgical applications. 
     As shown in  FIGS. 10A and 10B , the cutting head  24 C may be formed with a diameter of about 3 mm and with a flat distal end  74 . The flat distal end  74  may be helpful in pushing tissue out of the way of the cutting tool and establishing a clear edge for cutting. Positioned proximal to the distal end  74  is a cutting window  76 . The cutting window  76  may be oriented have a flat distal wall  78  that transitions to a flat inner edge  80  perpendicular to the flat distal wall. The flat inner edge  80  may transition to a proximally angled edge  82  (extending outwardly as the edge extends proximally). The flat distal wall  78  may have a height A from about 0.05 inches to about 0.15 inches, and more preferably about 0.10 inches. The flat inner edge  80  may have a length B of from about 0.03 inches to about 0.10 inches, and more preferably about 0.06 inches. The proximally angled edge  82  may extend at an angle C of from about 30 degrees to about 60 degrees, and more preferably about 45 degrees. 
     In use, a user moves the distal end  78  proximal to the tissue to be cut and then activates suction to pull the tissue into the cutting window  76 . The actuator  30  is then manipulated by the user to move the shaft  44  distally with the blade  46  of the shaft moving across the cutting window  76  to cut whatever tissue is in the cutting window. The cutting head  24 C allows surgeons a more traditional cutting method for procedures, such as, for example, meniscectomies and soft-tissue debridement and removal. 
     As shown in  FIGS. 11A and 11B , the cutting head  24 D may be formed with a distally angled distal end  84  that extends beyond a diameter of the cannula  18 . In an implementation, the distally angled edge has an angle A of from about 65 degrees to about 95 degrees, and more preferably about 80 degrees. The distally angled edge may have a height B of from about 0.10 inches to about 0.20 inches, and more preferably about 0.15 inches. The distally extending sloped end  84  may be helpful in lifting tissue or in maneuvering the cutting head between closely positioned structures. 
     A proximal surface  86  of the sloped end  84  may form a distal wall of a cutting window  88 . In an implementation, the proximal surface  86  has an angle C of from about 30 degrees to about 60 degrees, and more preferably about 45 degrees. The proximal surface  86  of the sloped end  84  transitions to a flat inner edge  90  parallel to a longitudinal axis. In an implementation, the flat inner edge has a length D of from about 0.02 inches to about 0.10 inches, and more preferably about 0.06 inches. The flat inner edge  90  may transition to a proximally angled edge  92  (extending outwardly as the edge extends proximally). In an implementation, the inner edge  90  has an angle E of from about 55 degrees to about 85 degrees, and more preferably about 70 degrees. 
     In use, a user moves the sloped end  84  past the portion to be cut and then activates suction to pull tissue into the cutting window  88 . The actuator  30  is then manipulated by the user to move the shaft  44  distally with the blade  46  of the shaft moving across the cutting window  88  to cut whatever tissue is in the cutting window. This cutting head  24 D design allows for safe and efficient removal of bone and tissue, such as, for example, laminectomy within the spine without the need to remove the instrument from the spinal canal. The suction port eliminates the need of the surgeon to manually remove tissue and bone after each cut. 
     Use of the cutter, according to implementations, will now be described. With the suction control  58  in a closed position, the cannula  18  of the surgical cutting tool  10  is inserted into a patient. During insertion, the actuator  30  may be used to position the shaft  44  to cover the cutting window  72  to prevent tissue from entering the cutting window. Once at the desired location, movement of the cannula  18  is ceased. If desired, a user may rotate the cannula  18  using the knob  42  to change the orientation of the cutting head  24 . If desired, a user may also move the suction control  58  to variably position tissue within the cutting window  62  of the cutting head  24 . Once the tissue to be cut is positioned within the cutting window  62 , the user may manipulate the actuator  30  to move the shaft blade  46  across the cutting window  62  to cut the tissue. After the tissue has been cut, the user may release the actuator  30  and repeat the process to conduct additional cutting, or remove the cannula  18  from the patient. 
     The surgical cutting tool may be used, for example, in traditional and small joint arthroscopy and endoscopy. The surgical cutting tool may be used within a dry arthroscopic procedures without overheating concerns. Additionally, the surgical cutting tool may be used in standard arthroscopy with in-flow. Variable suction control allows the surgical cutting tool to be used in a broad variety of surgical procedures. Interchangeable cutting heads allow for the surgical cutting tool to be used in a broad variety of surgical procedures without the need for separate instruments. Additionally, the scissor grip and suction control allow for versatile single-handed operation. In an implementation, the handles  26 ,  30  and suction control  60  are made from Radel and the remaining components are made from stainless steel. 
     There is disclosed in the above description and the drawings, a surgical cutting tool and method that fully and effectively overcomes the disadvantages associated with the prior art. However, it will be apparent that variations and modifications of the disclosed implementations may be made without departing from the principles of the invention. The presentation of the implementations herein is offered by way of example only and not limitation, with a true scope and spirit of the invention being indicated by the following claims. 
     Any element in a claim that does not explicitly state “means” for performing a specified function or “step” for performing a specified function, should not be interpreted as a “means” or “step” clause as specified in 35 U.S.C. § 112.