while the present invention is susceptible of embodiment in various forms , there is shown in the drawings and will hereinafter be described a presently preferred embodiment with the understanding that the present disclosure is to be considered an exemplification of the invention and is not intended to limit the invention to the specific embodiments illustrated . referring generally to fig1 - 3 , a woven retractor sleeve 100 for providing access to a surgical site is illustrated . the woven retractor sleeve 100 is constructed to include a central portion 12 , a base end 10 and a proximal portion 14 . the retractor sleeve is generally tubular in cross sectional shape and can be made in a variety of sizes for different types of percutaneous surgical procedures . the base portion 10 is preferably provided with at least one , and more preferably a plurality of anchor members 16 . in general , the anchor members include a sloped side 18 and a catch side 20 . the anchor members are preferably constructed from a relatively rigid or spring like material to allow the directional engagement of the sleeve through the tissue or bone surrounding the surgical site while the anchors engage tissue and / or bone to secure the sleeve at the desired location . however , it should also be noted that the anchor members may be constructed from the same or similar material as the sleeve without departing from the scope of the invention . in this manner , the sleeve can be incrementally advanced to the surgical site . alternatively , the sleeve may be moved to the desired location and the anchors may be directly engaged to the tissue surrounding the surgical site . in one non - limiting embodiment , the anchor members 16 each include a v - shaped cross sectional shape , a sloped side 18 and a catch side 20 . the anchor members 16 may be secured at various locations along the retractor sleeve 100 by stitching , adhesive , weaving , fasteners or any suitable combination thereof . the proximal portion 14 of the retractor sleeve is preferably larger in diameter than the base end and may include at least one , and more preferably a plurality of apertures 22 sized and shaped to cooperate with one or more cage members 24 ( fig6 - 11 ). the apertures may also be utilized in conjunction with a drawstring member 26 ( fig4 ) to secure the retractor sleeve 100 to an insertion probe 28 as shown in fig4 . still referring to fig1 - 3 . the sidewall 30 of the retractor sleeve 100 is constructed from a fabric , e . g . woven and / or knit material , to provide properties not found within rigid retraction devices . it will be appreciated by those skilled in the art that , in the fabric produced in the weaving or knitting process , the longitudinal fibers 36 and the circumferential fibers 38 may not be distributed in discrete layers in the fabric . however , in the preferred embodiment of the instant invention , the fibers of one yarn are predominantly located on the technical front 32 of the fabric and the other yarn fibers are predominantly located on the technical back 34 of the fabric . this construction provides numerous advantages with respect to rigid type retractors . the fabric material allows the retraction sleeve to be reduced significantly in size or changed in shape for insertion . the woven construction permits the use of fibers or yarns having different properties extending through the fabric in longitudinal and circumferential directions . this will allow the retractor sleeve to expand in diameter beyond its static diameter for passage of an implant or tool providing shorter term retraction of tissue , nerve roots etc . to minimize trauma to the patient . the fabric may also include one of a variety of surface or face finishing including caustic reduction , napping , brushing , sueding , and shearing to increase surface filament count to increase surface acceptance of fluids . alternatively or in addition to the surface finishing , the fabric may be coated with a coagulant to increase surgeon visibility of the site by limiting blood flow into the surgical site . in at least one embodiment , the technical back includes fibers that extend primarily in the longitudinal direction , e . g . longitudinal fibers 36 . this construction allows implants and tools to be more easily slid across the surface of the retractor sleeve while the predominantly circumferential fibers on the outside of the sleeve provide gripping to the adjacent tissue to resist movement . the longitudinal fibers are preferably constructed from a high performance material / fabric , such as a ballistic resistant material / fabric , a high tensile strength material / fabric , nylon , an aramid material such as kevlar , spectra , twaron , dyneema , another synthetic material or any mixture of these . these materials provide some rigidity to the overall length of the retractor sleeve while resisting punctures and tears . in some embodiments , radio opaque fibers 40 extend along the length or portions of the length of the retractor sleeve for cooperation with surgical radiography to aid the surgeon in locating the device in the surgical site . the circumferential fibers 38 can be manufactured from a variety of fibers including cellulosic fibers , such as cotton , or synthetic petrochemical fibers , such as polyester . the fibers may be used in 100 % form , or from blended fibers , including cellulosic fiber in combination with synthetic fibers , either in mechanical or intimate blends . spandex ( such as lycra ® manufactured by dupont ), monofilament , rubber , or elastomerics may be utilized or introduced to the fabric construct to create an expandable diameter sleeve . referring to fig4 and 5 , the retractor sleeve 100 is illustrated in a first compact configuration cooperating with an insertion probe 28 . in fig4 the retractor sleeve is wrapped about an insertion probe 28 having a central shaft 42 . the central shaft includes a sharp distal end 44 for ease of tissue penetration . the insertion probe is preferably constructed of a biocompatible material and may be constructed to transfer electrical current to a neuro - monitoring device to aid the surgeon in avoiding nerve structures . a drawstring 26 may be provided to secure the retractor sleeve in place about the insertion tool . the sleeve can , after insertion be released by pulling or cutting the drawstring to release the retractor . fig5 illustrates an alternative embodiment of the insertion probe 28 . in this embodiment , the central shaft is a hollow shaft 46 and may include a deployment window 48 for deploying the retraction sleeve . referring to fig6 - 11 , various types of cage members are illustrated . in general , the cage members are constructed and arranged to hold the retractor sleeve in a second open position . the cage members may include spikes 50 that project through the retractor sleeve to engage tissue or bone . the cage members may be constructed from various materials that may be rigid , resilient or elastic in nature . in some embodiments , the cage member may include telescoping joints 52 that may be used alone or in combination with spring and / or rigid materials . it is to be understood that while certain forms of the invention are illustrated , it is not to be limited to the specific forms or arrangements herein described and shown . it will be apparent to those skilled in the art that various changes may be made without departing from the scope of the invention and the invention is not to be considered limited to what is shown and described in the specification and any drawings / figures included herein . one skilled in the art will readily appreciate that the present invention is well adapted to carry out the objectives and obtain the ends and advantages mentioned , as well as those inherent therein . the embodiments , methods , procedures and techniques described herein are presently representative of the preferred embodiments , are intended to be exemplary and are not intended as limitations on the scope . changes therein and other uses will occur to those skilled in the art which are encompassed within the spirit of the invention and are defined by the scope of the appended claims . although the invention has been described in connection with specific preferred embodiments , it should be understood that the invention as claimed should not be unduly limited to such specific embodiments . indeed , various modifications of the described modes for carrying out the invention which are obvious to those skilled in the art are intended to be within the scope of the following claims .
the present invention is directed to methods and instruments for performing tissue retraction in minimally invasive spinal surgery . another specific application includes surgical methods performed through the percutaneously retracted tissue at any location in a patient &# 39 ; s body . the tissue retraction is provided by an elongated sleeve formed from fabric materials , which may include the ability to stretch beyond their original length along at least one axis , for passage of instruments or implants .