Abstract:
A minimally invasive method for drilling into bone and for providing for delivery of medical treatment is provided. The method includes use of a drilling system includes a miniature shaft, a bit, a guide tube encapsulating the shaft during drilling and a cortex adapter thereafter to prevent closure of the drilled hole, a stylet to prevent blockage of the resulting passage, and introduction for treatment following removal of the stylet. As a result, a hole, targeted towards a cancerous lesion within the bone, is possible.

Description:
CROSS REFERENCE TO RELATED APPLICATIONS 
       [0001]    This application is a divisional of U.S. Non-Provisional patent application Ser. No. 12/437,910 filed May 8, 2009, to which priority is claimed, and which was a continuation in part of U.S. Non-Provisional patent application Ser. No. 12/064,276, which is the national entry of PCT/US08/54085, which claimed the benefit of U.S. Provisional Patent Application Ser. No. 60/890,831 entitled, “Directional Bone Drilling and Methods of Treatment” filed on Feb. 20, 2007 in the United States Patent and Trademark Office and U.S. Provisional Patent Application Ser. No. 60/891,183 entitled, “Directional Bone Drilling and Methods of Treatment” filed on Feb. 22, 2007 in the United States Patent and Trademark Office. 
       STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT 
       [0002]    Not applicable. 
     
    
     BACKGROUND OF THE INVENTION 
       [0003]    1. Field of Invention 
         [0004]    The present invention relates to an apparatus to provide delivery of medical treatment to and within tissue or bone. In particular the present invention relates to a minimally invasive and particularly small treatment delivery system including a drill and treatment delivery passage. Additionally, the present invention relates to a minimally invasive and particularly small apparatus for drilling of passages in bone for other purposes, such as the imposition of screws or other devices to fix a bone or bone portion in position. 
         [0005]    2. Description of the Related Art 
         [0006]    Delivery of medical treatments to tissue, particularly hard tissue and notably the tissue within bone, is particularly difficult. Historically treatment has been delivered through the entire body in sufficient application amounts to ensure the necessary treatment amount reaches the desired tissue. As can be expected, this requires application amounts far in excess of the treatment amount necessary and can result in damage to other parts of the body as well as increased costs. Various solutions have been developed to attempt to reduce the application amount, typically by attempting to isolate the affected area from the body, including shunting of blood flow in the affected limb through a heart/lung machine to allow continued circulation within the limb while isolating the blood flow from the rest of the body. Similarly accessing bone to directly apply any treatment amount or to drill into the bone, such as drilling a passage for screws to fix a bone or bone particle in position, has historically been quite difficult and invasive. Moreover, such passages have generally been no smaller than 0.15875 cm (0.0625 inches). Likewise, drilling such passages has resulted in significant fracturing of the bone itself. 
         [0007]    The need therefore exists for apparatus to provide delivery of medical treatment to and within tissue, and notably to tissue within the bone, which permits direct application of only the necessary treatment amount and for a system to access tissue, and particularly tissue within a bone, to directly apply any treatment amount or to drill into the bone such as drilling a passage for screws to fix a bone or bone particle in position, with minimal invasion. A need further exists for an apparatus which may be used with tissue or with bone. 
         [0008]    Such a need may be particularly important in the treatment of osteosarcoma and similar cancers of bone. 
       BRIEF SUMMARY OF THE INVENTION 
       [0009]    The present invention overcomes the foregoing drawbacks of previous systems. 
         [0010]    The present invention provides an improved system to provide delivery of medical treatment to tissue, which may be within a bone, by providing an improved drill, hypodermic guide tube, a cortex adapter and a stylet. The drilling apparatus includes a miniature shaft, a bit, a hypodermic guide tube and a drive unit. The guide tube may comprise, in part, a hypodermic needle, thus providing a hypodermic guide tube. As a result, precise, straight holes may be drilled, targeted towards a cancerous lesion within the tissue. Once the bit reaches the desired depth, the hypodermic guide tube is retained in place, the bit withdrawn, and a capillary, referred to as a cortex adapter, is inserted through the hypodermic guide tube, through the hole in the bone and into the lesion. A stylet may be inserted in the capillary tube to prevent any movement of bodily fluids up the cortex adapter and to prevent coagulation about the opening of the cortex adapter. When needed, the stylet may be removed and the treatment directed to the tissue though the cortex adapter. 
         [0011]    Due to the small diameter of the drill, the hole drilled is particularly small. As can be anticipated a plurality of holes can be drilled, spaced apart to deliver specific quantities of treatment across the lesion. 
         [0012]    In another aspect of the present invention, the present invention provides an improved method of delivering medical treatment to and into bone. 
         [0013]    The foregoing and other objectives, features, and advantages of the invention will be more readily understood upon consideration of the following detailed description of the invention, taken in conjunction with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE SEVERAL DRAWINGS 
         [0014]    So that the manner in which the described features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof that are illustrated in the drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical preferred embodiments of the invention and are therefore not to be considered limiting of its scope as the invention may admit to other equally effective embodiments. 
           [0015]    In the drawings: 
           [0016]      FIG. 1  illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone. 
           [0017]      FIG. 2  illustrates a cross sectional view of the drilling and hypodermic guide tube portions of the present invention showing the relation of the shaft and hypodermic guide tube. 
           [0018]      FIG. 3  illustrates a cross-sectional view of the drilling and hypodermic guide tube portions of the present invention, providing a better image of the bit and hypodermic guide tube. 
           [0019]      FIG. 4  illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone in relation to a drive tube connected to the drill shaft. 
           [0020]      FIG. 5  illustrates a side view of the drilling and hypodermic guide tube portions of the preferred embodiment of the present invention in relation to the bone after penetration through the bone and into a cancerous lesion. 
           [0021]      FIG. 6  illustrates a side view of the hypodermic guide tube portion of the preferred embodiment of the present invention in relation to the bone after removal of the drill portion after penetration through the bone and into a cancerous lesion, leaving a usable passage to the cancerous lesion. 
           [0022]      FIG. 7  illustrates a side view of the hypodermic guide tube, cortex adapter and stylet portions of the preferred embodiment of the present invention when nested together. 
           [0023]      FIG. 8  illustrates a side view of the hypodermic guide tube, cortex adapter and stylet portions of the preferred embodiment of the present invention separated for clarity. 
           [0024]      FIG. 9  illustrates a side view of the hypodermic guide tube portion and cortex adapter portions of the preferred embodiment of the present invention in relation to the bone after penetration through the bone and into a cancerous lesion during delivery of a treatment. 
           [0025]      FIG. 10  illustrates one embodiment of the drive unit used with the drilling system. 
       
    
    
     DETAILED DESCRIPTION OF THE INVENTION 
       [0026]    The invention may be further understood by the following non-limiting examples. Although the description herein contains many specificities, these should not be construed as limiting the scope of the invention but as merely providing illustrations of some of the presently preferred embodiments of the invention. For example, thus the scope of the invention should be determined by the appended claims and their equivalents, rather than by the examples given. In general the terms and phrases used herein have their art-recognized meaning, which can be found by reference to standard texts, journal references and contexts known to those skilled in the art. The following definitions are provided to clarify their specific use in the context of the invention. All references cited herein are hereby incorporated by reference to the extent not inconsistent with the disclosure herewith. 
         [0027]    Referring to the  FIG. 1 , a portion of a drilling system  10 , for drilling into a living bone  100  is shown. The drive unit  1000 , depicted in  FIG. 10 , required for at least partial rotation of the bit  102 . The cortex adapter  702  and the stylet  710 , depicted in  FIG. 7 , are not shown. While drilling system  10  is described for use in drilling into bone, it may be used to drill into other body tissues. The drilling apparatus includes a bit  102 , a shaft  104 , and a hypodermic guide tube  106 . 
         [0028]    Referring to  FIG. 1 , the hypodermic guide tube  106  may comprise a hypodermic needle section  108 , a hypodermic adapter fitting  110  at the receiving end  112  of the hypodermic guide tube  106 , and a sharp non-coring tip  114  at the penetrating end  116  of the hypodermic guide tube  106 . The hypodermic guide tube  106  therefore has a passage through its body along its length. 
         [0029]    Referring to  FIG. 2 , in the preferred embodiment the hypodermic guide tube  106  is particularly small compared to the bone to be drilled or the body to be entered. The inner diameter  202  of the hypodermic guide tube  106  may be quite small. 
         [0030]    Referring to  FIGS. 2 and 3 , the shaft  104  and the bit  102  of the drilling system  10  are depicted. A portion of the shaft  104  proximate the first end  306  may be flattened and shaped to produce a bit  102 , which may be a spade drill bit. Different bits, such as spherical, helical twist, or burr cutting tips, may alternatively be used. Unlike standard drill bits, which have high strength and brittleness, the bit  102  is quite ductile. As can be appreciated, the loss of such a drill bit in the body, made more likely with a brittle drill bit, is to be avoided. The bit  102  has a width  302  smaller than the inner diameter  202  of the hypodermic guide tube  106 , such that the hypodermic guide tube  106  limits the flexing of the shaft  104  but permits withdrawal of the shaft  104  with the bit  102  after use. The bit  102  also has a drill point or cutting edge  304 . The shaft  104  therefore has a quite small outer diameter  200 . The hypodermic guide tube  106  is therefore sized to surround the shaft  104 . 
         [0031]    Referring to  FIG. 4 , a drive tube  402 , having a larger diameter than the shaft  104 , may enclose the shaft  104  at its shaft second end  404  so the shaft  104  may be connected to a motor or other radial driver to at least partially rotate the shaft  104  and to a linear driver to drive the bit  102  into the bone  100  in operation. The drive tube  402 , affixed or connected to the shaft  104 , provides for better application of rotational and linear force due to its larger size, but the shaft  104  may be drive without a drive tube  402 . 
         [0032]    Referring again to  FIG. 1  and to  FIG. 5 , the shaft  104  has a length sufficient to fully pass through the hypodermic guide tube  106  and to drill through the wall  118  of the bone  100 . 
         [0033]    In operation, the hypodermic guide tube  106  is placed in abutment or proximate to the tissue, here bone  100 , at its penetrating end  116 . The drilling system  10  may be delivered directly to the bone or tissue to be drilled by driving the hypodermic guide tube  106  through tissue. Alternatively, the drilling system  10  may be placed adjacent or proximate the bone  100  after site preparation, which may include surgical relocation of intermediate parts of the body  120 , such as muscle and blood vessels. 
         [0034]    Referring to  FIGS. 1 ,  3 , and  5 , the hypodermic guide tube  106  may include a sharp non-coring tip  114  extending from the hypodermic guide tube penetrating end  116 . The length of the sharp non-coring tip  114  is sufficient to maintain a desired angle of drilling while the penetrating end  116  contacts the bone  100  and prevents the cutting tip  304  from contacting the bone  100  prior to advancing the cutting bit  102 . The sharp non-coring tip  114  is sized to ensure contact between the hypodermic guide tube  106  and the bone  100  before the cutting bit  102  begins cutting into the bone  100  at the desired angle of attack. Referring to  FIG. 1 , by virtue of the sharp non-coring tip  114 , the hypodermic guide tube  106  contacts the bone  100 , or tissue on the surface of the bone  100 , and becomes stationary, thereby preventing the cutting bit  102  from walking away from the point of its initial contact with the bone  100  or tissue on the surface of the bone  100 . Moreover, as the sharp non-coring tip  114  provides a limited point of contact between the bone  100  and the hypodermic guide tube  106 , any chips of bone  100  created by the cutting bit  102  are not trapped adjacent to the cutting bit  102  but rather may escape the passage  502 , depicted in  FIG. 5 , created by the cutting bit  102 . 
         [0035]    Referring to  FIG. 5 , the shaft  104  is then driven so that the bit  102  is rotated against the bone  100 , while the shaft  104  is advanced, cutting through the bone wall  118 , until reaching the marrow  122  and creating a passage  502 . 
         [0036]    Referring to  FIG. 6 , the bit  102 , and the shaft  104  are then withdrawn from the hypodermic guide tube  106 , leaving only the hypodermic guide tube  106  in contact with the bone  100  and in communication with the passage  502 . The sharp non-coring tip  114  is therefore of critical importance in maintaining the position of the hypodermic guide tube  106  relative to the passage  502  and to providing the means to identify the location of the passage  502 . 
         [0037]    Referring to  FIGS. 7 and 8 , a cortex adapter  702  having a capillary  704  with an interior passage is provided for insertion into the passage of guide tube  106  and ultimately into the tissue passage  502 , which may be into the marrow  122 , permitting delivery of the treatment  900  as shown in  FIG. 9 . The hypodermic adapter fitting  110  of the hypodermic guide tube  106  may include a tapered conic cavity  706  adapted to direct the bit  102  and the drill shaft  104  into the hypodermic needle section  108  via hypodermic adapter fitting  110  of the hypodermic guide tube  106 . The cortex adapter  702  may be constructed to include a nose  708  to fit into the tapered conic cavity  706  of the hypodermic guide tube  106  and may similarly include a tapered conic cavity  714  adapted to direct the stylet  710  into the hypodermic needle section  108  of the hypodermic guide tube  106 . Referring to  FIG. 9 , the capillary  704  of the cortex adapter  702  is sized and capable of passing through the passage of the hypodermic guide tube  106  and extends the length of the hypodermic guide tube  106 , through the passage  502  and through the bone  100  and the marrow  122  to provide a controlled passage of any treatment  900 . Referring now to  FIGS. 8 and 9 , as previously mentioned, the drilling system  10  also includes a stylet  710 , which is utilized to plug the cortex adapter  702  when the cortex adapter  702  is not in use, to prevent outflow through the cortex adapter  702 , and to prevent coagulation of blood in or at the end of passage  502 . To accomplish these goals, the wire section  718  of stylet  710  is capable of fitting within and through the cortex adapter  702  and may preferably extend the entire length of the capillary  704  and into the marrow  122 , as depicted in  FIG. 7 . The stylet  710  may be constructed to include a nose  716  to fit into the tapered conic cavity  714  of the cortex adapter  702 . The wire section  718  of the stylet  710  is sized to fit within the cortex adapter  702  sufficiently close to preclude outflow of bodily fluids through the cortex adapter  702 , but not so close as to be irremovable from the cortex adapter  702 . Ideally both the cortex adapter  702  and the wire section  718  of the stylet  710  have cylindrical cross-sections to encourage this close fit. 
         [0038]    Referring to  FIG. 8 , an exploded view of the constituent parts, including the hypodermic guide tube  106 , the cortex adapter  702 , and the stylet  710  are depicted. 
         [0039]    Referring to  FIG. 9 , when sufficient numbers of cortex adapters  708  have been inserted into the tissue, the treatment  900  may be introduced into the cancerous lesion  124  through the cortex adapter  702 . 
         [0040]    The bone  100  is relatively soft when drilled in this manner, thus the drilling system  10  is capable of drilling through the bone  100  without deleterious effects on the surrounding bone. Moreover, the drilling system  10  produces a uniform, clean and particularly small diameter passage  502  through the bone  100 . As a result of the small passage  502  directed toward the cancerous lesion  124 , any of the various treatments known in the art, such as chemotherapy, radiochemical therapy, directed energy, may be provided without damage of adjacent tissue. 
         [0041]    Referring to  FIG. 10 , the drilling system  10  may be driven by a drill unit  1000 . The drive unit  1000  may include a rotating motor  1002  capable of operable connection to the shaft  104  and capable of at least partially rotating the shaft  104 . In the preferred embodiment, the rotating motor  1002  is a rotating motor. The rotating motor  1002  may operate at a fixed speed and is ideally activated when the control arm  1006  is engaged, although a variable speed rotating motor  1002  may be used and as the rotating motor  1002  may be activated by other switches, such as a simple switch or a foot pedal. Regardless of the type of activation used or the fixed or variable speed, the operating speed of the rotating motor  1002  is sufficiently high to efficiently cut the bone  100  without fracturing the bone and low enough to prevent generating thermal necrosis. A control arm  1006  associated with the drive unit  1000  may be moved through a range of positions, causing a linear drive  1004  to advance. The advance of the linear drive  1004  may be proportional to the movement of control arm  1006 , particularly if the control arm  1006  is moved radially, thus providing a moment about a pivot to provide a linear drive  1004 . The proportion of movement may be set to provide a leverage advantage in linearly driving the shaft  104 . The control arm  1006  may also be spring-loaded to cause the linear drive  1004  to retreat as the control arm  1006  is released. Alternatively, the control arm  1006  may be connected to a processor or other system to proportionally multiply the movement of the control arm  1006  to the input of a linear drive  1004 . The linear drive  1004  may be coupled or otherwise related to the shaft  104 , which may be via a connection of the linear drive  1004  to the rotating motor  1002 . Thus as the linear drive  1004  advances and retreats by operation of the control arm  1006 , the shaft  104  likewise advances or retreats. 
         [0042]    In either embodiment, the bit  102  drills through the bone  100  to provide for application of the medical treatment  900 , as illustrated in  FIG. 9 . Once a passage  502  has been drilled through the bone  100 , the medical treatment  900  may be introduced toward the cancerous lesion  124 . The treatment  900  may be chemotherapy, radiotherapy, heat therapy or any other therapy known in the art. The amount of treatment  900  necessary for effective treatment may be far less than typically applied when given orally or introduced into the blood stream since the treatment  900  is introduced proximate the cancerous lesion  124 . Likewise, the treatment  900  may be more effective as a result of directed application. As can be appreciated, the flow of the treatment  900  through the cortex adapter  702  toward the cancerous lesion  124  is limited by the uptake by the cancerous lesion  124  of the treatment  900 . 
         [0043]    Alternatively, the treatment  900  may be directed toward the cancerous lesion  124  by a charge-driven application (not shown). Thus it may be possible to enhance the flow of the treatment  900  by applying a direct current potential between the cortex adapter  702  and an electrode in conductive contact with the exterior of the limb placed as closely as possible to the region of the cortex adapter  702 . In one embodiment, a very fine liquid aerosol is generated and applied through electrostatic charging. In one embodiment, a liquid is passed through a nozzle, wherein a plume of droplets is generated by electrically charging the liquid to a very high voltage. The charged liquid in the nozzle becomes unstable as it is forced to hold more and more charge. Soon the liquid reaches a critical point, at which it can hold no more electrical charge and at the tip of the nozzle it blows apart into a cloud of tiny, highly charged droplets. These tiny droplets are particularly small, and fly about searching for a potential surface to land on that is opposite in charge to their own. Such droplets would be attracted to the cancerous lesion due to electrical differential. The system may employ a sharply pointed hollow metal tube, such as a syringe needle, with liquid pumped through the tube. A high-voltage power supply may then be connected to the outlet of the tube and the tube positioned proximate a cancerous lesion  124 . When the power supply is turned on and adjusted for the proper voltage, the liquid being pumped through the tube transforms into a fine continuous mist of droplets that fly rapidly toward the cancerous lesion  124 . 
         [0044]    Alternatively, if the treatment  900  consists of direct energy to be applied to the cancerous lesion  124 , an optical tube sheathed in a metal, such as nickel, may be used to direct the treatment  900 . 
         [0045]    Additionally, via the passage  502 , it is possible to visually observe the cancerous lesion  124 , such as with appropriately-sized fiber-optic or laparoscopic devices. 
         [0046]    Thus in operation, the drilling system  10  is applied to or in close proximity to the bone  100  at the penetrating end  112  of the hypodermic guide tube  106 . The shaft  104  and the bit  102  are rotated sufficient to cut the bone  100 . Force is linearly applied to the shaft  104 , which drives the bit  102  into the bone  100  and through the bone wall  118  to create a passage  502 . Additionally, it is possible to direct the hypodermic guide tube  106  against the bone  100  towards the cancerous lesion  124  from the opposite side of the cancerous lesion  124 . The shaft  104  and bit  102  are removed from the hypodermic adapter fitting  110  of the hypodermic guide tube  106  and the cortex adapter  702  and its capillary  704 , together with a stylet  710  therein, are inserted into the hypodermic adapter fitting  110  of the hypodermic guide tube  106 . While the cortex adapter  702  may alternatively be first inserted into the hypodermic guide tube  106  and the stylet  710  inserted thereafter, this is not the most desired operation as it permits backflow of bodily fluids into the cortex adapter  702 . When the treatement  900 , which may be radioactive, is ready to introduction, the stylet  710  is removed and the treatment introduced. Thereafter the hypodermic guide tube  106  and the cortex adapter  702  are removed, thus leaving treatment  900  at the desired location. 
         [0047]    The terms and expressions which have been employed in the foregoing specification are used therein as terms of description and not of limitation, and there is no intention, in the use of such terms and expressions, of excluding equivalents of the features shown and described or portions thereof.