Cerebral and lumbar perfusion catheterization apparatus for use in treating hypoxic/ischemic neurologic tissue
This is a continuation of application Ser. No. 755,427, filed July 16, 1985 now abandoned which is a continuation-in-part of Ser. Nos. 428,900, filed Sept. 30, 1982, U.S. Pat. No. 4,758,431 and Ser. No. 582,961, filed Feb. 23, 1984, U.S. Pat. No. 4,686,085. Ser. No. 582,961 is, in turn, a division of Ser. No. 428,850, filed Sept. 30, 1982, now U.S. Pat. No. 4,445,500 which along with Ser. No. 428,900 U.S. Pat. No. 4,758,431 are both, in turn divisions of Ser. No. 354,346, filed Mar. 3, 1982, now U.S. Pat. No. 4,445,886 and which in turn is a continuation-in-part of Ser. No. 139,886 filed Apr. 14, 1980, now U.S. Pat. No. 4,378,797. 
    
    
     FIELD OF THE INVENTION 
     This invention relates in general to cerebral and lumbar catheterization apparatus useful for the perfusion or drainage of fluids from the cerebral and spinal regions and, in particular, it relates to an apparatus particularly useful in treating hypoxic/ischemic neurologic tissue arising from cerebral vascular accident by allowing the circulation of oxygen carrying synthetic liquids through the neurologic tissue. 
     RELATED APPLICATIONS AND PATENTS 
     In addition, the present application is related to the following issued U.S. Patents, all of which are incorporated herein by reference as if set forth in full and all of which are divisions of one or the other of the aforementioned Ser. Nos. 139,886 and 354,346: 
     U.S. Pat. No. 4,445,514 entitled &#34;Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,393,863, entitled &#34;Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,450,841, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,445,887, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,446,154, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,446,155, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,451,251, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,445,888, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     U.S. Pat. No. 4,445,500, entitled &#34;Stroke Treatment Utilizing Extra Vascular Circulation of Oxygenated Synthetic Nutrients to Treat Tissue Hypoxic and Ischemic Disorders&#34;; 
     BACKGROUND OF THE INVENTION 
     Cerebral vascular accident, a disease commonly known as &#34;stroke&#34; remains the third leading cause of death, and probably constitutes the single largest category of long-term disability in this country. In spite of current medical knowledge and available treatments, a major central system vascular occlusion is quickly attended by irreversible damage to the affected brain region(s). A &#34;completed stroke&#34; is manifest by a fixed and permanent neurological deficit. Millions of dollars have been expended in stroke research and care by federal and private agencies without a single substantial gain in our present chemotherapeutic abilities for a completed stroke. 
     In each of the aforementioned patents and applications, however, the present applicant has disclosed and claimed a novel nutrient formulation for circulation through cerebro-spinal fluid pathways, and systems and methods for using the same to treat central nervous tissue hypoxic-ischemic conditions. Applicant has recognized that there is a therapeutic time window through which neurons can be reached and resuscitated. 
     In accordance with the inventions disclosed and claimed in the aforementioned patents and applications, a synthetic cerebro-spinal fluid is circulated through the cerebro-spinal fluid passageways immediately after a stroke. Specifically, the oxygenated nutrient is circulated through those cerebro-spinal fluid passageways which contact brain and spinal cord tissue. According to these methods, treated tissues exhibit a substantially improved ability to resist and/or repair damage which would otherwise result from vascular occlusion. 
     The circulation apparatus disclosed in the aforementioned patents and applications comprises a reservoir containing a nutrient emulsion; means for delivering the nutrient emulsion at preselected flow rates; an oxygenation means for equilibriating the nutrient emulsion to desired gaseous tension levels; heat exchanger and/or cooling unit means for selectively controlling the temperature of the nutrient emulsion; filter means for cleansing the nutrient emulsion; and circulation monitoring means for ensuring the desired circulation flows are maintained within the system. Specifically, in carrying out the method described and claimed in the aforementioned patents and applications, the nutrient emulsion is delivered from the nutrient emulsion reservoir to the lateral ventricle of the brain. Injection of the nutrient input stream directly to the brain permits the oxygenated nutrient emulsion to come into contact with the subarachnoid spaces, miniature Virchow-Robins spaces, cerebral and cord surfaces, and cerebral ventricles. Circulation of the nutrient input stream through at least a portion of the cerebro-spinal pathway may be accomplished by withdrawing fluid from the spinal subarachnoid space, or alternatively, from the cisterna magna. 
     While the aforementioned system and method have been found to be particularly useful in the treatment of stroke, treatment must be begun within a therapeutic time window immediately following the onset of the stroke. Because time is so critical, treatment must be administered by paramedics and emergency personnel or, alternatively, by emergency room physicians and staff. Since the treatment described in the aforementioned patents and applications requires the injection of oxygenated nutrient emulsion directly into the lateral ventricles of the human brain and the withdrawal of that nutrient emulsion from the subarachnoid space or the cisterna magna, it should be clear that the procedures used in the treatment are not ones which paramedics and emergency personnel or even most emergency room personnel are familiar with. 
     Specifically, the treatment requires that an aperture be formed in the cranium and that a catheter be inserted directly through the aperture of the skull and thereafter through the soft tissue of the brain into the lateral ventricles. Such techniques are difficult enough for skilled neurosurgeons and are typically beyond the ken of paramedical personnel. 
     SUMMARY OF THE INVENTION 
     It is an object of the present invention to provide a cerebral and lumbar perfusion catheterization apparatus for use in treating hypoxic/ischemic neurologic tissue which may be easily utilized by paramedics and by emergency room personnel. 
     It is a further object of the present invention to provide such a perfusion catheterization apparatus which may be utilized quickly and with utmost accuracy so that treatment may be begun as soon as possible after the onset of stroke symptoms. 
     To accomplish these results, a novel method and apparatus are provided for rapidly inserting a cerebral perfusion catheter into the lateral brain ventricle. 
     In accordance with the apparatus of the present invention a placement appliance for engaging the head is provided having guide means for receiving and directing a catheter to the lateral brain ventricle. The appliance accurately positions the guide means with respect to the head at a location offset from the center line. The guide means is a tubular structure having a threaded internal bore. The catheter further includes an external threaded portion mating with the internal threaded bore of the guide means such that when the catheter and guide means are mated, the insertion depth of the catheter may be precisely controlled by the rotational position of the catheter with respect to the guide means. A locking means is provided to ensure that once the catheter is inserted into the lateral ventricle, the position of the catheter vis-a-vis the guide means remains fixed during treatment so that the insertion depth does not vary during treatment. 
     In accordance with the method of the present invention, the aforementioned placement appliance having guide means is applied to the head o the patient such that the guide means are positioned at a location offset from the center line of the head, with the center line of the bore of the aforementioned guide means being directed toward the lateral ventricles. An aperture is created through the skull at the location of the guide means and thereafter the catheter is inserted through the guide means and the skull using the guide means to direct the catheter toward the lateral brain ventricle. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     The present invention will be more fully understood by reference to the accompanying drawings, in which: 
     FIG. 1 is a frontal view of a patient wearing a cerebral catheterization apparatus in accordance with the present invention; 
     FIG. 2 is a side or lateral view of the patient wearing the cerebral catheterization apparatus of FIG. 1, but with the catheter means removed therefrom; 
     FIG. 3 is a top view of the patient and cerebral catheterization apparatus shown in FIG. 2; 
     FIG. 4 is a partial cross-sectional view through the cerebral catheterization apparatus shown in FIG. 3 along section lines 4--4, but with an obturator situated within the guide means thereof; 
     FIG. 5 is a cross-sectional view similar to that shown in FIG. 4, but with a drill means situated within the guide means thereof; 
     FIG. 6 is a cross-sectional view similar to that shown in FIG. 4, but with the catheter means of the present invention situated within the guide means, the catheter having a tip portion of a first configuration; 
     FIG. 7 is a schematic view of a lumbar catheterization apparatus useful in connection with the cerebral catheterization apparatus of the present invention; 
     FIG. 8 illustrates the tip of both the cerebral and the lumbar catheter means of the present invention in a first position suitable for insertion; and 
     FIG. 9 illustrates the tip of both the cerebral and the lumbar catheter means of the present invention but in a second position after insertion. 
    
    
     DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS 
     In the following more detailed description of the present invention, numerous examples have been selected for the purpose of explanation and illustration of the preferred embodiment. One of ordinary skill in the art will readily recognize that numerous substitutions or alterations from the embodiment set forth may be made without departing from the spirit of the present invention, which is defined by more particularly in the appended claims. 
     Referring now to FIG. 1, the cerebral catheterization apparatus of the present invention is shown generally at 10. The cerebral catheterization apparatus 10 is shown fitted on to a patient 11. The apparatus 10 is utilized for reliably inserting a cerebral perfusion catheter means 12 and 13 to the left and right lateral brain ventricles 16 and 18 of the patient 11. As shown in FIG. 1, the cerebral catheterization apparatus 10 includes an appliance for engaging the head having guide means shown generally at 20 and 22 for receiving and directing the catheter means 12 and 13. 
     In order that the guide means 20 and 22 may be quickly and reliably positioned with respect to the left and right lateral brain ventricles 16 and 18 by emergency personnel, the guide means 20 and 22 are affixed to a harness 24 which accurately positions them with respect to the head of the patient 11. The harness 24 includes a horizontal strap 26 which is positioned about the head slightly above the ears and eyebrows. As best seen in FIG. 2, therefore, the horizontal strap 26 is positioned adjacent the forehead 28 at the anterior portion of the head and is positioned adjacent the occipital protuberance 30 at the posterior portion of the head The horizontal strap 26 is thus positioned with respect to the head such that the vertex of the skull is located above the strap. The horizontal strap 26 includes a fastening means 32 which preferably includes a thumb screws 34 and 42 permitting the circumferential size of the horizontal strap 26 t be adjusted depending on the head size of the patient 11. When fitted on a patient, the horizontal strap is adjusted using both of these screws to take up the same amount of strap slack, thereby establishing (bilateral) symmetry of the head to the apparatus 10. 
     The harness 24 further includes chin straps, one of which is shown at 36, for maintaining the horizontal strap 26 in a fixed position with respect to the head. The chin straps are affixed to the horizontal strap 26 on the left and right sides of the head of the patient 11. The chin straps are joined by a buckle or other fastening means beneath the chin. The harness 24 further includes a vertical transverse strap 40 which is also affixed to the horizontal strap 28 and to which the guide means 20 and 22 are affixed. Like the horizontal strap 26, the vertical transverse strap 40 also includes adjustment means, such as racheted slides, to accommodate varying head sizes. This may be accomplished by providing indicia on each tounge 40c of the strap 40 which indicate its position relative to its strap guide 115 which is attached to the horizontal strap 28. The tounges 40a and 40g may have rachet racks 40d and 40e protruding from one surface thereof, to selectively engage complimentally formed protrusions or teeth on the strap guides 115. This engagement permits rapid adjustment of the strap 40, but holds it firmly in place once properly positioned. The vertical transverse strap 40 is generally positioned parallel to and lies directly above the coronal suture, i.e., the juncture between the frontal and parietal skull bones. 
     As may best be seen in FIG. 3, also joined to the horizontal strap 26 is a vertical medial strap shown generally at 44. The vertical medial strap 44 includes a first or anterior portion 46 which joins the horizontal strap 26 in the vicinity of the forehead at 28 and a second or posterior portion 48 which joins with the horizontal strap 26 in the vicinity of the occipital protuberance 30. The first or anterior portion 46 and the second or posterior portion 48 of the vertical medial strap 44 join with the vertical transverse strap 40 in a position 45 which is intermediate the guide means 20 and 22. Such a position lies roughly over the bregma, i.e., the juncture between the coronal and saggital sutures of the skull. The vertical medial strap 44 is effective in appropriately positioning the guide means 20 and 22 in the anterior-to-posterior direction over the bregma. 
     Once the harness 24 and, therefore, the guide means 20 and 22 are appropriately positioned with respect to the head of patient 11, treatment is begun immediately. Referring now to FIGS. 4-6, the method of utilizing the cerebral catheterization apparatus 10 of the present invention in the course of such treatment will be described in further detail. After the positioning harness 24 described in connection with FIGS. 1-3 is located with respect to the head of the patient and the guide means 20 and 22 are positioned in the appropriate location with respect to the lateral ventricles 16 and 18 as described above, apertures are created through the skull at the position of the guide means 20 and 22. These apertures are formed in the skull 60 by means of an obturator 54 as shown in FIG. 4. The obturator 54 includes a handle portion 56 and an elongated stem portion 58 having an outside diameter fitting within the threaded internal bore 60 of the respective guide means 20 or 22. The obturator 54 is utilized to pierce the scalp 59 of the patient and to remove a core of that scalp so as to expose the underlying skull 60. After the core has been removed and the skull 60 has been exposed, the obturator 54 is removed from the guide means 20 or 22 as the case may be an the next step of the present method may begin. 
     This next step is shown in FIG. 5 in which a drill means 62 is shown. The drill means 62 includes a handle portion 64 and a downwardly extending drill bit 66. In accordance with the preferred embodiment of the present invention, the drill means further includes a stop 68 concentrically located about the outer periphery of the drill bit 66 and fixed with respect to the drill bit 66 by means of a set screw 70. Operation of the handle portion 64 of the drill means 62 causes an aperture to be formed in the skull 60 as will a in the underlying pia layer 72. The stop means 68 is provided to prevent the insertion of the drill bit 66 into an unnecessarily large portion of soft brain tissue 74. When the drill bit 66 is inserted to the appropriate depth, the stop means 68 abuts the upper surface of the guide means 20 or 22 as shown in FIG. 5 to control the insertion depth. 
     After the scalp 58 has been pierced and an aperture has been formed in the skull 60, the drill means 62 is removed from the guide means 20 and the third and next step of the present method may begin. 
     In this next step, a catheter means such as shown at 12 in FIG. 6, is inserted into the threaded internal bore 60 of the guide means 20 or 22. The catheter means 12 includes a tip portion 76 which is inserted into the lateral ventricle such as shown at 16 in FIG. 6. With the insertion of the catheter tip 76 into the lateral ventricle, treatment in accordance with the aforementioned patents and patent applications may begin and nutrient emulsion may be circulated through the ventricle. 
     In accordance with an important aspect of the present invention, the catheter means 12 includes a threaded external portion 78 which mates with and which is threadedly engaged with respect to the threaded internal bore 60 of the guide means 20 or 22 and external indicia which indicate the depth of insertion. The rotational position of the catheter means 12 with respect to the guide means 20 thus controls and provides a visual indication of the insertion depth of the catheter means 12. The proper insertion depth is determined by reference to the aforementioned indicia on the tongues 40a and 40b of the vertical strap 40. These indicia are scales to correspond to indicia on the catheter means so that the catheter insertion distance can be read from tongues 40a and/or 40b. This is possible due to the precise placement of the horizontal and vertical straps in the harness, and their known relative positions with respect to the lateral ventricles. It is therefore unnecessary for the user to have any particular knowledge of brain anatomy in order to properly insert the catheter once the harness is properly positioned. When the catheter means 12 is at the proper insertion depth, thumb screws 13 and 15 (FIG. 1) may be tightened so as to fix the catheter means 12 at the appropriate depth. 
     In accordance with another aspect of the present invention, the catheter means 12 and 14 each include a first port 79 through which nutrient emulsion is caused to flow and a second or pressure measurement port 80 through which intracranial pressure is monitored. Also passing through the pressure measurement port 80 is a wire means 81 which is coupled to the extreme end 77 of the catheter tip 76 for reasons which will become apparent below. The catheter means 12 is preferably made of semi-malleable plastic and is provided with multiple slit ports 86 at the tip 76 thereof. The slit ports 86 are spaced about the peripheral wall of the tip 76 of the catheter means 12. 
     To complete the treatment of the present invention, it is necessary that the nutrient emulsion which is inserted into the lateral brain ventricles be removed from the spinal subarachnoid space or, alternatively, from the cisterna magna. In order to facilitate removal of the nutrient emulsion from the subarachnoid space an improved lumbar catheter is described in connection with FIG. 7. As shown in FIG. 7, a lumbar catheter shown generally at 90 is inserted into the spinal column 92 of the patient 11. The lumbar catheter 90 includes a tip portion 96 and a body portion 98. The lumbar catheter 90 is made of semi-malleable plastic and is flexible at least at its inserted tip portion 96 so as to bend and protrude from the subarachnoid space of the spinal column 92 and project through the body wall. The lumbar catheter 90 is inserted into the subarachnoid space by first inserting a knife cannula into a hollow tube and using it to penetrate the skin, muscle and dura. When the tip of the knife and hollow tube are inserted into the subarachnoid space, the knife is withdrawn and the catheter is inserted into the hollow tube. 
     As shown in FIGS. 8 and 9 and in accordance with an important aspect of the present invention, both the cerebral catheters 12 and 14 and the lumbar catheter 90 include a thin wire 81 traversing through the central bore 100 thereof. The thin wire 84 is fixed to the extreme end portion 77 of the catheter means. As mentioned above and as shown in FIGS. 8 and 9, peripheral slit ports 86 are provided around the peripheral surface of the catheter tip 76. As shown in FIG. 8, the catheter tip 76 is initially in an undeformed position and the peripheral slits 86 are closed, thus making insertion of the catheter means relatively simple. After the catheter tip 76 has been inserted, the central wire 81 is moved to a retracted position, thus deforming the catheter tip 76 and expending the radial dimension of the catheter tip 76 as shown in FIG. 9. Such a result has the effect of expanding the slits 86 and transforming them to the more enlarged apertures 86A shown in FIG. 9. Such a result improves the flow of fluid emulsion both into and from the catheter means 12 or 90 as the case may be. 
     While a particular embodiment of the present invention has been shown and described, it will be appreciated that other embodiments may occur to those skilled in the art and such other embodiments come within the spirit and scope of the appended claims.