Devices and methods for percutaneous surgery

Abstract

Devices and methods for performing percutaneous spinal surgery under direct visualization and through a single cannula are shown. A device ( 10 ) is provided which includes an elongated cannula ( 20 ) having a first inner diameter (D I ) and an outer diameter (D O ) sized for percutaneous introduction into a patient. The cannula ( 20 ) defines a working channel ( 25 ) between its ends ( 21, 22 ) which has a second diameter (D 2 ) equal to the diameter (D I ) of the cannula sized for receiving a tool therethrough. An elongated viewing element ( 50 ) is engageable to the cannula ( 20 ) adjacent the working channel ( 25 ), preferably by a fixture ( 30 ). The fixture ( 30 ) includes a housing ( 31 ) attachable to the proximal end ( 22 ) of the cannula ( 20 ) that defines a working channel opening ( 35 ) which is in communication with the working channel ( 25 ). The housing ( 31 ) also defines an optics bore ( 60 ) adjacent the working channel opening ( 35 ). In certain embodiments, the fixture ( 30 ) supports the viewing element ( 50 ) for translation and/or rotation within the optics bore ( 60 ) along the longitudinal axis of the bore, and for rotation of the housing ( 31 ) relative to the cannula ( 20 ) so that the longitudinal axis of the optics bore ( 60 ) will rotate about the longitudinal axis of the working channel ( 25 ). Methods are also provided for performing spinal surgeries percutaneously with direct visualization and without the requirement for a fluid-maintained workspace.

What is claimed:  
     
         1 . A device for use in percutaneous spinal surgery, comprising: 
 an elongated cannula having a first inner diameter and an outer diameter sized for percutaneous introduction into a patient, said cannula further including a distal working end and an opposite proximal end, said cannula defining a working channel between said ends having a second diameter equal to said first inner diameter sized for receiving a tool therethrough; and    an elongated viewing element mounted inside said cannula adjacent said working channel, said viewing element having a first end connectable to a viewing apparatus and an opposite second end disposed adjacent said distal working end of said cannula.    
     
     
         2 . The device of  claim 1  wherein said second inner diameter is sized to simultaneously receive a plurality of tools therethrough.  
     
     
         3 . The device of  claim 1 , wherein said elongated viewing element includes a lens at said second end and an image transmission channel extending therefrom.  
     
     
         4 . The device of  claim 3 , wherein said elongated viewing element is a fiber-optic cable having illumination fibers and image transmission fibers.  
     
     
         5 . The device of  claim 1 , further comprising a fixture for mounting said elongated viewing element to said cannula.  
     
     
         6 . The device of  claim 5 , wherein said fixture is configured to mount said viewing element within said working channel.  
     
     
         7 . The device of  claim 5 , wherein said fixture includes: 
 a housing attached to the proximal end of the cannula, said housing defining a working channel opening therethrough in communication with the working channel, said working channel opening sized to substantially correspond to said second diameter of said working channel to receive a tool therethrough;    said housing further defining an optics bore adjacent said working channel opening, said optics bore sized to receive said elongated viewing element therethrough.    
     
     
         8 . A device for use in percutaneous spinal surgery, comprising: 
 an elongated cannula sized for percutaneous introduction into a patient having a distal working end and an opposite proximal end and defining a working channel between said ends, said working channel having an inner diameter sized to receive a tool therethrough;    an elongated viewing device having a first end connectable to a viewing apparatus and a second end including a lens positionable adjacent said working end of said cannula; and    a fixture connected to said proximal end of said cannula adjacent to said working channel and defining an optics bore having a longitudinal axis, said optics bore sized to removably receive said elongated viewing device therethrough, and said fixture supporting said viewing device for movement within said optics bore along the longitudinal axis of said bore to extend or retract said lens relative to said distal working end of said cannula.    
     
     
         9 . The device of  claim 8  wherein said elongated viewing element includes a lens at said second end and an image transmission channel extending therefrom.  
     
     
         10 . The device of  claim 9 , wherein said lens defines an optical axis, said optical axis being offset at an angle relative to said longitudinal axis of said optics bore.  
     
     
         11 . The device of  claim 9 , wherein elongated viewing element is a fiber-optic cable having illumination fibers and image transmission fibers.  
     
     
         12 . The device of  claim 8 , wherein said fixture is configured to support said viewing element within said working channel.  
     
     
         13 . The device of  claim 8 , wherein said fixture includes: 
 a housing attached to the proximal end of the cannula, said housing defining a working channel opening therethrough in communication with the working channel, said working channel opening sized to substantially correspond to said second diameter of said working channel to receive a tool therethrough;    said housing further defining said optics bore adjacent said working channel opening.    
     
     
         14 . A device for use in percutaneous spinal surgery, comprising: 
 an elongated cannula having a distal working end and an opposite proximal end and defining a working channel between said ends, said working channel having an inner diameter sized to receive a tool therethrough;    an elongated viewing device having a first end connectable to a viewing apparatus and a second end including a lens positionable adjacent said working end of said cannula; and    a fixture connected to said proximal end of said cannula adjacent to said working channel and defining an optics bore having a longitudinal axis, said optics bore sized to removably receive said elongated viewing device therethrough, and said fixture supporting said viewing device for rotation within said optics bore about the longitudinal axis of said bore.    
     
     
         15 . The device of  claim 14  wherein said elongated viewing element includes a lens at said second end and an image transmission channel extending therefrom.  
     
     
         16 . The device of  claim 15 , wherein said lens defines an optical axis, said optical axis being offset at an angle relative to said longitudinal axis of said optics bore.  
     
     
         17 . The device of  claim 15 , wherein said elongated viewing element is a fiber-optic cable having illumination fibers and image transmission fibers.  
     
     
         18 . The device of  claim 14 , wherein said fixture is configured to support said viewing element within said working channel.  
     
     
         19 . The device of  claim 14 , wherein said fixture includes: 
 a housing attached to the proximal end of the cannula, said housing defining a working channel opening therethrough in communication with the working channel, said working channel opening sized to substantially correspond to said second diameter of said working channel to receive a tool therethrough;    said housing further defining said optics bore adjacent said working channel opening.    
     
     
         20 . The device of  claim 14 , wherein said fixture further supports said elongated viewing device for movement within said optics bore along said longitudinal axis of said bore.  
     
     
         21 . A device for use in percutaneous spinal surgery comprising: 
 an elongated cannula having a distal working end and an opposite proximal end and defining a working channel between said ends, said working channel having a first longitudinal axis and ana inner diameter sized to receive a tool therethrough; and    a fixture mounted to said proximal end of said cannula, said fixture including a housing defining a working channel opening in communication with said working channel of said cannula and an optics bore for receiving an elongated viewing device therethrough in communication with said working channel, said optics bore having a second longitudinal axis substantially parallel to said first longitudinal axis, said housing being rotatable relative to said cannula so that said second longitudinal axis of said optics bore rotates about said first longitudinal axis of said working channel.    
     
     
         22 . The device of  claim 21 , further comprising an elongated viewing device disposed within said optics bore, said viewing device having a first end connectable to a viewing apparatus and a second end including a lens positionable adjacent said working end of said elongated cannula.  
     
     
         23 . The device of  claim 21 , wherein: 
 said cannula has an outer diameter; and    said housing defines a receiving bore having an inner diameter slightly larger than said out diameter of said cannula, wherein said proximal end of said cannula is received within said receiver bore so that said housing can rotate about said proximal end of said cannula.    
     
     
         24 . The device of  claim 23 , wherein said housing further includes an upper bore contiguous with said working channel opening and in communication with said receiver bore, said optics bore being disposed within said upper bore of said housing.  
     
     
         25 . The device of  claim 21 , wherein said optics bore is defined by a C-shaped clip.  
     
     
         26 . The device of  claim 25 , wherein said C-shaped clip is formed of a resilient material and said optics bore defined by said clip has an inner diameter that is slightly less than an outer diameter of said elongated viewing device so that said viewing device resiliently deflects said C-shaped clip when said viewing device is disposed within said optics bore.  
     
     
         27 . The device of  claim 23 , wherein said housing further defines a number of grooves in said receiver bore.  
     
     
         28 . The device of  claim 27 , further comprising sealing members disposed in each of said number of grooves, said sealing members disposed between said housing and said outer diameter of said cannula.  
     
     
         29 . The device of  claim 21  wherein said working channel opening has a diameter substantially equal to said inner diameter of said working channel.  
     
     
         30 . The device of  claim 21  wherein said fixture includes engagement means, disposed between said housing and said cannula when said fixture is mounted to said proximal end of said cannula, for providing a gripping engagement between said housing and said cannula.  
     
     
         31 . The device of  claim 30 , wherein said engagement means includes a number of resilient rings disposed between said housing and said cannula.  
     
     
         32 . A device for supporting an elongated viewing device within a cannula defining a working channel, comprising: 
 a fixture mountable to said proximal end of the cannula, said fixture including a housing defining a working channel opening arranged to communicate with the working channel when said fixture is mounted to the cannula, said working channel opening sized to receive tools therethrough, and said housing further defining an optics bore for receiving an elongated viewing device therethrough and arranged so that the viewing device received within said optics bore will extend into the working channel of the cannula when said fixture is mounted to the cannula.    
     
     
         33 . The device of  claim 32 , in which the cannula defines a first longitudinal axis, wherein said optics bore defines a second longitudinal axis substantially parallel to the first longitudinal axis when said fixture is mounted on the cannula, said housing being rotatable relative to said cannula so that said second longitudinal axis of said optics bore rotates about the first longitudinal axis of the cannula.  
     
     
         34 . The device of  claim 32  in which the cannula has an outer diameter, wherein said housing defines a receiving bore having an inner diameter slightly larger than the outer diameter of the cannula, so that said housing can rotate about the cannula.  
     
     
         35 . The device of  claim 34 , wherein said housing further includes an upper bore contiguous with said working channel opening and in communication with said receiving bore, said optics bore being disposed within said upper bore of said housing.  
     
     
         36 . The device of  claim 35 , wherein said optics bore is defined by a C-shaped clip.  
     
     
         37 . The device of  claim 36 , wherein said C-shaped clip is formed of a resilient material and said optics bore defined by said clip has an inner diameter that is slightly less than an outer diameter of the elongated viewing device so that the viewing device resiliently deflects said C-shaped clip when the viewing device is disposed within said optics bore.  
     
     
         38 . The device of  claim 34 , wherein said housing further defines a number of grooves in said receiver bore.  
     
     
         39 . The device of  claim 38 , further comprising O-rings disposed in each of said number of grooves, said O-rings disposed between said housing and the outer diameter of the cannula when the cannula is disposed within said receiver bore.  
     
     
         40 . A tissue retractor for use in percutaneous surgery through a cannula having an inner cylindrical surface, said retractor comprising: 
 a working tip configured to atraumatically displace tissue as the retractor is manipulated through the tissue; and    a body having a proximal first end and a distal second end, said second end being integral with said working tip, said body having a convex surface configured to conform to the inner cylindrical surface of the cannula when said tissue retractor is disposed within the cannula, said body sized to be rotatable received within the cannula and having a length from a said first end to a said second end sufficient so that said first end and said working tip can be outside the cannula when said body is within the cannula.    
     
     
         41 . The tissue retractor of  claim 40 , wherein said working tip has a blunt curved end.  
     
     
         42 . The tissue retractor of  claim 40 , wherein said body includes a curved plate defining said convex surface and an opposite concave surface.  
     
     
         43 . The tissue retractor of  claim 42 , wherein said curved plate includes opposite edges extending substantially parallel to said length of said body, said curved plate subtending an arc between said opposite edges of at least 200 degrees.  
     
     
         44 . The tissue retractor of  claim 43 , wherein said curved plate subtends an arc between said opposite edges of about 270 degrees.  
     
     
         45 . The tissue retractor of  claim 40 , wherein said body includes: 
 a first plate portion defining a first convex surface and an opposite first concave surface and including first opposite edges extending substantially parallel to said length of said body, said first plate portion subtending a first arc between said first opposite edges; and    a second plate portion integral with said first plate portion and disposed between said first plate portion and said working tip, said second plate portion defining a second convex surface and an opposite second concave surface and including second opposite edges extending substantially parallel to said length, said second plate portion subtending a second arc between said second opposite edges that is different from said first arc.    
     
     
         46 . The tissue retractor of  claim 45 , wherein said first arc subtends an angle of less then 180 degrees and said second ar subtends an angle of more than 180 degrees.  
     
     
         47 . The tissue retractor of  claim 46 , wherein said first arc subtends an angle of about 90 degrees and said second arc subtends an angle of about 270 degrees.  
     
     
         48 . The tissue retractor of  claim 45 , wherein said second arc subtends an angle that decreases along said length toward said working tip.  
     
     
         49 . The tissue retractor of  claim 48 , wherein said second arc subtends an angle of about 200 degrees adjacent said first plate portion decreasing to an angle of less than 10 degrees adjacent said working tip.  
     
     
         50 . The tissue retractor of  claim 49 , wherein said first arc subtends an angle of about 200 degrees.  
     
     
         51 . The tissue retractor of  claim 40 , wherein said convex surface of said body is at a diameter that is greater than the diameter of the inner cylindrical surface of the cannula, said body being resiliently deformable to be insertable into the cannula with said convex surface in contact with the inner cylindrical surface of the cannula.  
     
     
         52 . The tissue retractor of  claim 40 , further comprising an arm attached to said proximal first end of said body, said arm having a gripping surface to facilitate manipulation of said tissue retractor.  
     
     
         53 . The tissue retractor of  claim 52 , wherein said arm is substantially perpendicular to said length of said body.  
     
     
         54 . A tissue dilator, comprising: 
 a sleeve having a tapered working end and an opposite end, said working end configured to displace tissue; and    a gripping portion on an outer surface of said sleeve adjacent said opposite end, said gripping portion defining a plurality of circumferential grooves configured for manually gripping the dilator to manipulate the dilator within tissue.    
     
     
         55 . A method for performing a surgical procedure at a location in a patient's body, comprising: 
 inserting a cannula into a patient through skin and tissue to create a working channel;    creating a working space in communication with the working channel and adjacent the location in the patient's body;    inserting optics through the working channel to the working space;    extending a first tool through the working channel to the working space; and    manipulating the first tool through the working channel to perform a surgical procedure on the location in the working space under direct vision from the optics and without directing irrigation fluid to the location.    
     
     
         56 . The method of  claim 55  wherein the tool is a power drill and the surgical procedure is drilling through bone or tissue at the location.  
     
     
         57 . The method of  claim 55 , further comprising: 
 extending the optics through the working channel beyond the end of the working channel adjacent the working space for direct visualization of the working space and manipulating the tool.    
     
     
         58 . The method of  claim 55 , further comprising: 
 removably inserting a second tool through the working channel simultaneous with the first tool; and    manipulating the second tool to perform a function at the location.    
     
     
         59 . The method of  claim 58  further comprising: 
 inserting a guidewire into a patient through skin and tissue to the location;  
 inserting a cannulated dilator over the guidewire and through the skin and tissue to the location wherein the inserting the cannula includes inserting the cannula over the dilator;  
 removing the guidewire after inserting the dilator; and  
 removing the dilator after inserting the cannula.  
 
     
     
         60 . A method for performing a surgical procedure at a location on the spine, comprising: 
 inserting a cannula into a patient through skin and tissue to create a working channel;    creating a working space in communication with the working channel and adjacent the location on the spine;    extending a tool through the working channel beyond the end of the working channel and manipulating the tool in the working space; and    extending optics through the working channel beyond the end of the working channel adjacent the working space to directly visualize the working space and manipulation of the tool.    
     
     
         61 . A method for performing a surgical procedure at a location on the spine, comprising: 
 inserting a cannula into a patient through skin and tissue to create a working channel;    creating a working space in communication with the working channel and adjacent the location on the spine;    removably inserting a first tool through the working channel;    manipulating the first tool to perform a function at the location;    removably inserting a second tool through the working channel simultaneous with the first tool; and    manipulating the second tool to perform a function at the location.    
     
     
         62 . The method of  claim 61  wherein: 
 the first tool is a tissue retractor; and  
 the step of manipulating the first tool includes manipulating the tissue retractor to retract tissue to maintain the working space.  
 
     
     
         63 . A method for performing a discectomy at a subject vertebral level on the spine, comprising: 
 creating an incision in the skin substantially directly posterior to the subject vertebral level;    creating a bore through the lamina at a posterior medial position on the spine;    mounting a cannula through the incision at the bore in the lamina to create a working channel;    inserting optics through the cannula to directly visualize the location on the spine underneath the working channel;    extending a retractor through the working channel to retract tissue to create a path to the spinal disc;    extending the optics through the working channel an d path to the spinal disc; and    extending and manipulating discectomy instruments through the working channel to the disc to perform a discectomy under direct vision by the optics.    
     
     
         64 . The method of  claim 63  wherein the creating a bore includes conducting a laminectomy comprising the steps of: 
 inserting a cannula into the incision and through tissue to the lamina to define a working channel;  
 extending optics through the working channel to directly visualize the lamina; and  
 extending a bone cutting tool through the working channel and manipulating the tool to perform a laminectomy under direct vision from the optics.  
 
     
     
         65 . A method for performing a laminectomy, comprising: 
 creating an incision in the skin substantially directly posterior to the subject vertebral level;    inserting a cannula into the incision and through tissue to the lamina to define a working channel;    extending optics through the working channel to directly visualize the lamina; and    extending a bone cutting tool through the working channel and manipulating the tool to perform a laminectomy under direct vision from the optics.    
     
     
         66 . A method for implanting a vertebral fixation element, comprising: 
 making an incision in the skin to provide access to the location on the vertebra at which the fixation element is to be implanted;    inserting a cannula into the incision and through tissue to the location to define a working channel;    inserting optics through the cannula to directly visualize the location;    extending an insertion tool supporting the vertebral fixation element through the working channel to the location under direct vision; and    manipulating the insertion tool to implant the fixation element at the location under direct vision from the optics.