Configured and sized cannula

Abstract

A dilator retractor and the dilators that are used for minimally invasive spinal surgery or other surgery are configured to accommodate the anatomical structure of the patient as by configuring the cross sectional area in an elliptical shape, or by forming a funnel configuration with the wider end at the proximate end. In some embodiments the distal end is contoured to also accommodate the anatomical structure of the patient so that a cylindrically shaped, funnel shaped, ovoid shaped dilator retractor can be sloped or tunneled to accommodate the bone structure of the patient or provide access for implants. The dilator retractor is made with different lengths to accommodate the depth of the cavity formed by the dilators.

1 .- 20 . (canceled) 
     
     
         21 . A dilator kit, comprising:
 a non-cannulated dilator having an elongated cylindrical solid body with a tool engaging portion at a proximal end thereof and a pointed tip portion at a distal end thereof;   a plurality of cannulated dilators, at least one of the cannulated dilators having an ovoid cross-section;   the plurality of cannulated dilators includes a first cannulated dilator having a circular interior cross-section and an ovoid exterior cross-section and a second cannulated dilator having an ovoid interior cross-section and an ovoid exterior cross-section; and   at least one of the plurality of cannulated dilators having a distal facing surface disposed in a plane that is substantially perpendicular to a longitudinal axis of the at least one of the plurality of cannulated dilators,   wherein the non-cannulated dilator is sized to be received within the first cannulated dilator and the first cannulated dilator is sized to be received within the second cannulated dilator.   
     
     
         22 . The kit of  claim 21 , wherein each of the plurality of cannulated dilators has a beveled distal end that defines a sharp edge. 
     
     
         23 . The kit of  claim 21 , wherein each of the cannulated dilators has a distal-facing surface disposed in a plane that is substantially perpendicular to a longitudinal axis of the at least one of the plurality of cannulated dilators. 
     
     
         24 . The kit of  claim 21 , wherein at least one of the cannulated dilators has a funnel-shaped proximal end. 
     
     
         25 . The kit of  claim 21 , wherein each of the cannulated dilators has a different length. 
     
     
         26 . A dilator retractor, comprising:
 an elongate body extending from a proximal end to a distal end;   a central working lumen extending through the elongate body from the proximal end to the distal end; and   the distal end including an angled distal-facing surface disposed in a plane that is obliquely angled relative to a longitudinal axis of the elongate body, the distal-facing surface being configured to be in contact with a vertebra of a patient.   
     
     
         27 . The dilator retractor of  claim 26 , wherein the angled distal-facing surface is sloped to follow a slope of a posterior portion of a vertebra. 
     
     
         28 . The dilator retractor of  claim 26 , wherein the angled distal-facing surface is configured to be positioned against the vertebra between the facet joint and the spinous process. 
     
     
         29 . The dilator retractor of  claim 26 , wherein the angle of the angled distal-facing surface is a function of statistical dimensions of bone structures for a variety of different sized spinal structures. 
     
     
         30 . The dilator retractor of  claim 26 , wherein the distal end of the retractor includes a bevel that defines a sharp edge. 
     
     
         31 . The dilator retractor of  claim 26 , wherein the elongate body includes a conically shaped portion that tapers in a proximal to distal direction.