Patent Publication Number: US-2010121250-A1

Title: Dual Channel Shunt Device and Method for Ventriculo-Peritoneal Shunting of Bloody Cerebrospinal Fluid

Description:
CROSS-REFERENCE TO RELATED INVENTIONS 
     This application is based on and claims the priority of U.S. Provisional Patent Application No. 60/771,691 filed on Feb. 9, 2006 and entitled “Device of Ventriculo-Peritoneal Shunting of Bloody Cerebrospinal Fluid” and U.S. Provisional Patent Application No. 60/804,659 filed on Jun. 14, 2006 and also entitled “Device of Ventriculo-Peritoneal Shunting of Bloody Cerebrospinal Fluid” both by inventor Francis J. Pizzi, the entire contents and substance of both of which are hereby incorporated in total by reference. 
    
    
     BACKGROUND OF THE INVENTION 
     Description of Related Art 
     The incidence of obstructive hydrocephalus caused by a spontaneous hemorrhage in the brain is currently in excess of 60,000 cases per year in the USA. This number is increasing due to the more prevalent usage of blood thinners (coumadin, heparin, herbal remedies, Vitamin E Supplement) and platelet inhibitors (aspirin, Plavix®) for cardiac conditions and stroke prevention in the aging baby boomer population. A patient on these medications has a far greater chance of developing a hemorrhagic stroke versus a non-hemorrhagic stroke from a brain vessel occlusion. Additionally, minor head trauma in these patients is more likely to cause a bruise to the brain with bleeding into the cerebrospinal fluid pathways. 
     On an almost daily basis, the average neurosurgeon is confronted with an acutely ill patient who has sustained a spontaneous hemorrhage in their brain. Most of the time, these hemorrhages will extend into the cerebrospinal fluid system. In this system, fluid is produced at a rate of 20 cc. per hour in the lateral ventricles and must make its way through a series of passages of very small diameter to outflow at the junction of the brain and spinal cord. This fluid then is resorbed at a rate of 20 cc. per hour by the venous system which transports it to the kidneys where it is excreted. Blood particles in this pathway may clog up the smaller passages preventing the fluid from reaching the area where it is resorbed. The fluid continues to be produced but cannot be resorbed, thus an accumulation of the bloody fluid distends the ventricles, pouches deep in the hemispheres of the brain. The distended ventricles put pressure on the brain and the patient slips into a coma and dies. 
     The neurosurgeon must do something to relieve the pressure in the brain caused by the obstructive hydrocephalus. One option is to perform a ventriculo-peritoneal shunt using a tube with an integrated one way valve as shown in  FIG. 1A . One end of the tube is inserted through a hole in the skull and is passed through the substance of the brain into the cavity or ventricle of the brain where the fluid is produced. This tube is then tunneled under the scalp to the one way valve and then through another subcutaneous tunnel to the peritoneal cavity of the abdomen. Here the fluid drains and is absorbed by the lining, then absorbed by the veins of the lining and transported to the kidneys for excretion. Neurosurgeons have been doing this procedure successfully for over 50 years utilizing many different valved systems to treat hydrocephalus that is not associated with blood in the cerebrospinal fluid. In the presence of blood within the spinal fluid, these valved shunt systems commonly fail due to blood particles blocking the very small passages in the valve. With shunt blockage by blood, the hydrocephalus will once again recur to jeopardize the brain and re-operation is mandated. 
     The life saving treatment of choice by the neurosurgeon for the vast majority of patients with obstructive hydrocephalus secondary to blood particle obstruction of the cerebro-spinal fluid pathways is External Ventricular Drainage (EVD) as shown in FIG.  1 B. This involves making a hole in the skull, inserting a tube through the brain substance into the ventricle, and attaching it to an external bag where the bloody fluid drains. A staff member periodically empties the fluid as shown in  FIG. 1C . The amount of fluid drained is regulated by positioning the tube coming from the ventricle at a level about 10 cm. higher than the patients head as shown in  FIG. 1B . This creates a hydrostatic pressure so that any time the fluid pressure inside the brain exceeds 10 cm. of water pressure (normal), fluid will drain. Fluid continues to be produced in the ventricles at 20 cc. per hour. This will eventually dilute the bloody fluid as can be seen by observing the transparent drainage tube. At this time the neurosurgeon has the choice of removing the EVD (with the hope that the blood particles obstructing the fluid passages in the brain have cleared) or performing the above described ventriculo-peritoneal shunt as shown in  FIG. 1A . 
     There are prior art patents and literature references to devices which relate, in some respects, to the present invention. For example, U.S. Pat. No. 4,781,673 describes a “Brain ventricle shunt system with flow-rate switching mechanism”. This patent is related in that dual channels leading to valves of different flow rate can be isolated with an on-off switch. The device allows the neurosurgeon to choose one of two valves of different flow rates with tubes leading either to the atrium of the heart or to the peritoneal cavity. In that valves are present which can become blocked with blood particles, this would not be applicable to a patient with obstructive hydrocephalus secondary to bloody cerebrospinal fluid. 
     Likewise, U.S. Pat. No. 5,154,693 describes a “Flow control device having selectable alternative fluid pathways”. This allows choice of one of two valved pathways to select appropriate flow rates to drain fluid in the hydrocephalic patient in the absence of blood in the cerebrospinal fluid. See also U.S. Pat. No. 5,167,615. 
     Certain isolated features of the present invention and method are also known in the prior art. For example, an on-off switch as shown in  FIG. 6B  is described in the patent literature as early as in U.S. Pat. No. 3,827,439. Anti-siphon devices are also known in the literature and described, for example, in U.S. Pat. No. 4,795,437 and 6,953,443. 
     A more recent iteration of the above is U.S. Pat. No. 5,167,615 which adds a magnetically controlled switch to allow selection of pathway to a flow valve. None of these devices or methods solves the problem of obstructive hydrocephalus secondary to blood in the cerebrospinal fluid pathways. 
     There are many deficiencies and patient risks associated with the device and method (see  FIG. 1C ) of external ventricular drainage (EVD) which is the current art for treating obstructive hydrocephalus due to hemorrhage into the cerebro-spinal fluid pathways of the brain. 
     Life threatening meningitis (infection of the outer coverings of the brain) and or ventriculitis (infection of the inner lining of the ventricle) occurs in excess of 11% of patients treated with the current art in one series. See Wilberger, J. E., et al. Neurosurgery, 27:208-213, 1990. In a more recent study there was a 7% infection rate. See Mayhall, C. G., et al. N. Engl. J. Med., 310:553-559, 1984. All studies agree that the longer an EVD is left in the ventricle, the higher the infection rate. Infection is caused by establishment of a fluid pathway between the cavity of the brain and the hospital ICU (Intensive Care Unit) environment which is contaminated with many diverse bacterial pathogens. 
     An EVD is external to the body and can become dislodged. Commonly a patient with an impaired level of consciousness is restless and sometimes combative. These patient motions can cause dislodgement of the tube in the brain cavity and it will no longer function properly. Additionally, hospital staff, when moving a poorly responsive patient in their bed, can accidentally dislodge the drain tube. In both of these circumstances, re-operation is necessary to replace the drain catheter to relieve pressure on the brain. Re-operation requires passing a tube through the substance of the brain into the ventricle. Each time this is done there is a 1.4% chance of causing a hemorrhage into the substance of the brain. See Narayan, R. K., et al. J. Neurosurg., 56:650-659, 1982 
     Staff mishandling of the EVD can cause over drainage of fluid from the ventricle due to siphoning. This will cause the brain to collapse away from the inner table of the skull. The bridging veins from the brain surface to the main draining veins that are attached to the skull are torn away and begin hemorrhaging over the brain surface. This causes a subdural hematoma which must be surgically drained. 
     When the fluid issuing through the EVD begins to clear from the dilution resulting from continuous production of cerebrospinal fluid in the ventricle, the neurosurgeon may choose to remove the tube. If hydrocephalus recurs from premature removal or a new bleed, the EVD must be replaced in another operation with a 1.4% chance of the procedure causing a hemorrhage into the substance of the brain. Blood when outside the blood vessels acts as an irritant to the brain and irritation causes scar tissue. After the EVD is removed, delayed hydrocephalus can occur due to scar tissue formed in the CSF pathways. A ventriculo-peritoneal shunt operation must be performed, usually on an emergent basis, to save the patient&#39;s life. 
     SUMMARY OF THE INVENTION 
     The proposed method and device, Dual Channel IVD (Internal Ventricular Drain)/Shunt, effectively eliminates deficiencies and patient jeopardies associated with the usage of the External Ventricular Drainage (EVD) method and device in the presence of obstructive hydrocephalus secondary to blood in the cerebrospinal fluid pathways. 
     A tube inserted in the ventricle through a hole in the skull is run under the scalp to an implanted device that receives the bloody ventricular fluid. The device splits into two channels, one with an on-off switch and the other with a ball-in-cone spring valve. The “on” position allows the bloody fluid to run in a subcutaneously implanted catheter directly to the peritoneal body cavity for re-absorption passing through an anti-siphon device with no interposed valves that could become blocked with blood particles. When the CT scans show the fluid becoming less bloody through normal dilution, the scalp over the switch is palpated into the “off” position thus diverting the diluted fluid to a one way pressure valve which then connects to the catheter going to the peritoneal cavity. 
    
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         FIG. 1A  is a diagram of a prior art ventriculo-peritoneal shunt. 
         FIG. 1B  is a diagram of a prior art External Ventricular Drain (EVD). 
         FIG. 1C  is a flow diagram illustrating the steps used to perform the prior art technique shown in  FIG. 1B . 
         FIG. 2  is a diagram of the preferred embodiment of the Dual Channel Shunt of the present invention for draining cerebrospinal fluid implanted in a patient. 
         FIG. 3  is a flow diagram illustrating the steps used to perform the preferred embodiment of the present invention as shown in  FIG. 2   
         FIG. 4  illustrates the preferred embodiment of the Dual Channel shunt shown in  FIG. 2 . 
         FIG. 5A  illustrates the initial path of the bloody fluid through the on-off switch of the dual channel shunt. 
         FIG. 5B  illustrates the path of the fluid after it has been determined by CT scan to be diluted through the pressure resistant ball-in-cone valve and after the on-off switch of the dual channel shunt has been switched off. 
         FIG. 6A  is detailed crossed sectional view of a pressure resistant ball-in-cone valve. 
         FIG. 6B  is a detailed cross-sectional view of an on-off switch including a reservoir and an anti-siphon device. 
         FIGS. 7A-7E  illustrate the typical steps taken to turn the on-off switch off or on and how to flush it. 
     
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENT OF THE INVENTION 
     During the course of this description like numbers will be used to identify like elements according to different figures that illustrate the invention. 
     Fluid ( 28 ) build up in the cavities of the brain, known as hydrocephalus, is familiar to lay people but is usually thought of as an affliction of a newborn child. Hydrocephalus also occurs in adults for various reasons. Neurosurgeons have been treating hydrocephalus in various ways for more than 50 years. The operative procedure of choice for both children and adults is called “Ventriculo-Peritoneal Shunt”. This prior art technique is illustrated in  FIG. 1A . Initially a burr hole  22  is drilled through the skull of the patient  10 . A ventricular catheter  14  is then inserted through the skull hole then through the brain substance into the lateral ventricle  12 . That is in turn connected to a valve that opens at a pre-set pressure to allow fluid  28  to drain through tube  26  when the pressure in the lateral ventricle  12  is greater than the pressure in the valve  34 . This tube is the passed through a tunnel under the skin to another incision in the upper abdominal area where the tube  18  is implanted in the peritoneal cavity  36 . The lining of the abdominal cavity  36 , the peritoneum, will absorb the fluid  28  and return it to circulation through the veins. The fluid  28  from the ventricle  12  now has another pathway to drain out without building up pressure and damaging the brain. The valve prevents too much fluid from draining and the consequences thereof. The steps of the prior art approach are graphically illustrated in  FIG. 1A . 
     The prior art system will work well provided that the fluid in the brain cavities is normal in protein content and does not contain blood. If blood or fluid with high protein content is present, the plastic tubing and/or the valve will become clogged. The shunt will fail causing a build up of fluid in the brain cavity and hydrocephalus with subsequent death. 
     Commonly, the patients will present emergently with the new onset of hydrocephalus due to a hemorrhage into the brain cavity from a stroke or from a brain injury. To save a person&#39;s life in these circumstances, the neurosurgeon will drill a hole  22  in the skull, insert a plastic tube  14  into the brain cavity  12  and allow the cerebrospinal fluid to drain externally into a bag  20 . This is called External Ventricular Drainage or EVD as shown in  FIG. 1B . 
     EVD solves the immediate life threatening situation but not the long term problem. The drain tube can only be left in place for a limited time because there is the constant threat of hospital acquired infection causing meningitis and/or ventriculitis, an infection of the lining of the ventricle cavity deep in the brain. The plastic tube and the fluid column within it establish a pathway for germs from the hospital environment to get into the brain through the drill hole in the skull. Additionally, a patent may become restless and combative as a result of their condition. It is not uncommon for a patient to accidentally pull the external drain out of their ventricle thus necessitating a replacement operation. 
     The neurosurgeon observes the fluid that drains from the brain cavity for several days. See  FIG. 1C . When the fluid has visually cleared of blood, the drain is either removed or a ventriculo-peritoneal shunt operation is performed to correct the long term problem. There is a greater likelihood that this newly implanted shunt, when done after several days of open external drainage, will become infected. This would then require removal of the shunt, external drainage again and the implantation of yet another shunt after the infection has cleared, an additional three surgeries. This chain of events can repeat itself again and again. 
     The present invention  30  is specifically intended to treat patients with hydrocephalus associated with bloody cerebrospinal fluid. External ventricular drainage is unnecessary and subsequent ventriculo-peritoneal shunting as a second procedure is unnecessary. Exposure to the risks of ventriculitis, meningitis, hemorrhage into the brain substance and multiple surgeries under anesthesia is eliminated. 
     To better understand the present invention  30  it is first helpful to understand the anatomy, physiology and pathology of the environment. There are several separate circulation systems in the human body. The most familiar of these is the blood system with its arteries and veins. The cerebrospinal fluid circulation system involves the production of a clear watery fluid in the brain cavities. This fluid is produced at a constant rate of 0.34 milliliters per minute or about 20 mm (four teaspoonfuls) per hour. This fluid must get out of the brain to be reabsorbed in the spinal canal; hence it is called cerebrospinal fluid. There are pouches deep within the brain substance which drain through openings that join in the mid-line at the third ventricle which is a narrow slit. The fluid then drains through a one millimeter diameter passageway through the center of the brain to emerge in the fourth ventricle. This drains to the upper spinal canal through tiny openings and then flows down the spinal canal where it is absorbed to go back into the veins. 
     If any of the passages, openings or tubes through which the fluid must traverse to get out of the brain become blocked or clogged, the fluid cannot emerge. Blood in the cerebrospinal fluid is notorious for doing this. The production of fluid continues at its same rate despite the blockage. Thus the cavities of the brain become enlarged and they put pressure on the surrounding brain tissue. The brain can accommodate this increased pressure for a time but eventually cannot, at which time the brain stops functioning. The patient lapses into a coma and shortly will die unless the pressure is relieved. 
     The most common cause of acute hydrocephalus is bloody cerebrospinal fluid. The most common causes of bloody cerebrospinal fluid are head injuries and hemorrhagic strokes. The blood clogs up the passageways through which the fluid produced in the brain must egress to get to the site of absorption in the spinal canal. 
     The incidence of hemorrhagic strokes is definitely increasing. There are several reasons for this. Life spans are increasing for men and women. The baby boomer population glut is entering the years when strokes occur. The greatest factor, however, is the aggressive treatment of people with anti-coagulants (heparin, coumadin, etc.) and platelet inhibitors (Plavix®, etc.) to treat cardiac conditions, partly blocked arteries and mini-strokes. Those who take medicines to reduce their chances of having a stroke can have a stroke despite this precaution. Compared to those who do not take anti-coagulants and/or platelet inhibitors they are much more likely to hemorrhage into the damaged area of the brain where the stroke occurred. This hemorrhage into the damaged area frequently extends into the ventricles causing bloody cerebrospinal fluid. 
     When people taking these medications sustain even a mild head injury they are prone to have a brain hemorrhage. When the head is struck or even shaken, the brain, which floats in the cerebrospinal fluid inside the skull sustains bruises from hitting the hard bone that protects it. We all know how even mild blood thinners such as aspirin can cause a minimal skin bruise to blossom into a large purple blotch. The same thing happens to the much more fragile brain surface. Blood from the bruise gets into the cerebrospinal fluid pathways and can cause a blockage of fluid flow with resultant hydrocephalus. 
     The preferred embodiment of the present invention  30  is shown in  FIG. 4 . All the components are unitized between the two “Y” connectors,  26 A,  26 B and  18 A and  18 B, continuing to the peritoneal catheter  18 . Fluid  28  from the cavity  12  in the brain passes through upper tube  26  and to the “Y” connector  26 A,  26 B and can go either toward an on-off switch  32  with an anti-siphon device  64  or toward the ball-and-cone valve  34  from either pathway,  26 A or  26 B, to the lower “Y” connector,  18 A or  18 B, and then through tubing  18  to the peritoneal cavity  36 . The “open” or “closed” (or “on” or “off”) setting of the switch  32  will determine the direction of fluid flow. The preferred embodiment of the switch  32  is the catalog number NL850-0155 on /off CSF reservoir with an anti-siphon device such as made by Integra NeuroSciences of Plainsboro, N.J. While that model comprises the preferred on/off device  32 , nevertheless, there may be other devices in the prior art that might work just as well. The on-off switch  32  is illustrated in cross-sectional detail in  FIG. 6B  and is shown as used in  FIGS. 7A-7E .  FIG. 6B  shows the components that comprise the on-off switch  32  which include pathway  26 A which passes through occluder  56  which in turn is connected to reservoir  58 . Reservoir  58  communicates to the on/off button  60 . Downstream from the on/off button  60  is the anti-siphon device  64  which connects to the exiting tubing  18 A which in turn is connected to tubing  18  which communicates with the peritoneal cavity  36 . Reservoir  58  is covered by a soft depressible skin  70  seen in  FIG. 7A . The on/off switch  32  is shown in the “open” or “on” position in  FIGS. 6B and 7A . In this mode, the bloody cerebrospinal fluid  28  from ventricle  12  flows through the device  32  unimpeded by obstacles or pressure restraint. Anti-siphon device  64  prevents over drainage of the CSF from the brain ventricle  12 . The structure of the anti-siphon device  64 , is known in the prior art. 
     In order to close the one-way switch  32 , a physician presses down with his or her finger  66  on the on/off control button  60  as shown in  FIG. 7B . The on/off device  32  is located under the scalp  24  of the patient  10  and its features can be accurately determined by the feel of an experienced neurosurgeon. The on/off device  32  remains closed in this position until otherwise opened by the neurosurgeon. It is highly unlikely that patient or staff mishandling could inadvertently cause the switch to open. 
       FIGS. 7C-7E  illustrate the known prior art technique for flushing the various tubes, reservoirs, and the ball-in-cone spring valve as shown in  FIG. 4 . This will not be described in greater detail except to note that the on/off control button  60  can be popped into its “open” or “on” state by pushing down with the index finger  66  on the top  70  of reservoir  58  while pushing down with a second finger  68  on the occluder  56 . 
     The pressure resistant ball-in-cone spring valve  34  is illustrated in detail in  FIG. 6A . Valves such as are known in the prior art and are sometimes referred to as Hakim valves. The preferred embodiment of the invention  30  employs an “OMNISHUNT™ One Piece Valve System Catalog No. 908-322 as manufactured by Integra NeuroScience of Plainsboro, N.J., also the manufacturer of the on/ off switch device  32 . The ball-in-cone pressure resistant valve  34  is connected at one end to inlet tubing  26 B and at the other end to outlet tubing  18 B. The spring pressure against the ball inside of the valve  34  dictates the resistance that it presents to the flow of cerebrospinal fluid  28  through inlet tubing  26 B. The preferred pressure resistance is over 40 mm of water and is preferably in the range of 40-80 mm of water. 
       FIG. 2  illustrates the manner in which the invention  30  is inserted into a patient  10  and  FIG. 3  graphically illustrates the steps that take place when the invention  30  is employed. Initially a burr hole  22  is drilled into the scalp  24  of patient  10  and a ventricular catheter  14  is inserted through the substance of the brain into the lateral ventricle  12  to drain cerebrospinal fluid  28  in a manner similar to that described with regard to the prior art and illustrated in  FIGS. 1A ,  1 B and  1 C. A catheter  26  carries the cerebrospinal fluid  28  under the scalp  24  of the patient  10  and down to an area behind the ear of the patient  10  as illustrated in  FIG. 2 . The dual-channel shunt device  30  is then attached to catheter  26  at the top end and to catheter  18  of the bottom end which directs cerebrospinal fluid  28  to the peritoneal cavity  36  of the patient  10 . Cerebrospinal fluid  28  can be directed either through pathway  26 A and the on/off device  32  through pathway  18 A to catheter  18 , or, it can be directed through  26 B and the one-way pressure resistant valve  34  and then through catheter  18 B to drainage catheter  18 . The method by which this is accomplished is illustrated in further detail in  FIG. 3 . 
     As shown in  FIG. 3 , if hydrocephalus is detected as shown in step  40 , a burr hole  22  is initially drilled through the skull of patient  10  after an incision through the scalp  24  is made as shown by step  41 . The plastic ventricular catheter tube is passed through the substance of the brain into the lateral ventricle. Catheter  26  is run under the scalp  24  and attached to the “Y” connector  26 A,  26 B of the dual-channel shunt device  30 , the second “Y” connector  18 A,  18 B through downstream shunt line  18  to the peritoneal cavity  36  as illustrated by step  41 . Because the cerebrospinal fluid  28  is bloody, it is initially directed through the on/off switch  32  with little or no resistance because on/off switch  32  is initially in the “open” state and drains into the peritoneal cavity  36  as shown by steps  42 ,  43  and  44 , respectively in  FIG. 3 . Under these initial conditions, the cerebrospinal fluid  28  takes the path of least resistance shown by the arrow in  FIG. 5A  through the on/off switch  32 . This comprises the initial setting for the patient  10  with acute hydrocephalus secondary to bloody cerebrospinal fluid. It permits a straight, no-pressure path to the abdominal cavity  36  with no valve resistance involved so that blood blockage can be avoided. 
     After a period of time the neurosurgeon determines through serial CT scans of the brain whether or not the fluid has become diluted enough so that it can pass through the one-way resistance valve  34 , as shown in step  45  of  FIG. 3 . Once the cerebrospinal fluid  28  is diluted enough, the neurosurgeon closes switch  32  to divert the clearer cerebrospinal fluid  28  through pressure resistance valve  34  as shown in step  46 A and  46 B of  FIG. 3 . At that point, the neurosurgeon pushes down with his/her finger  66  through the scalp  24  of the patient  10  onto the on/off control  60  of the switch  32  in the manner illustrated in  FIG. 7B . This step plugs the on/off device  32  so that it can no longer conduct the flow of cerebrospinal fluid  28  through pathway  26 A and  18 A and, instead, diverts the clearer cerebrospinal fluid  28  through the one-way pressure resistance ball-in-cone valve  34 . If the pressure of the cerebrospinal fluid  28  on the ball-in-cone pressure resistant valve  34  is above 40 mm of water and preferably in the range of 40-80 mm of water, as shown in step  47 , then the one-way ball-in-cone spring valve  34  opens up as shown in step  48  and passes the clearer cerebrospinal fluid  28  to the peritoneal cavity  36  as shown in step  44 . The result is that the cerebrospinal fluid  28  then takes the path through the pressure resistant ball-in-cone valve  34  shown by the arrow in  FIG. 5B . 
     In conclusion, the present invention has the following benefits over the prior art such as illustrated in  FIGS. 1A and 1B . 
     First, and of most importance, the device and method proposed eliminates the patient&#39;s risk of infection (meningitis and/or ventriculitis) from hospital acquired pathogens. The entire system is implanted within the body with no communication to the outside environment. There is no EVD apparatus for hospital staff to contaminate with bacteria by mishandling. 
     Second, the implanted device cannot become dislodged by patient movement or staff mishandling, so replacement surgery with its inherent risks is unnecessary. 
     Third, the Dual Channel IVD/Shunt does not need to be removed after bloody fluid has cleared. No subsequent surgery to insert a ventriculo-peritoneal shunt is necessary for either early or delayed recurrent hydrocephalus. All variables are addressed with the initial surgery. 
     Fourth, in the common circumstance of re-bleeding after an EVD has been removed, no further surgery is necessary. The Dual Channel IVD/Shunt can be re-opened to straight drainage to the peritoneal cavity by simply pressing the scalp over the on-off switch into the “open” position, thus avoiding another surgery. 
     Fifth, if the implanted device malfunctions due to obstruction, the Dual Channel IVD/Shunt can be cleared with an injection (saline, heparin etc.) through the scalp into the implanted reservoir rather than with repeat surgery. The device can be palpated to direct the fluid injected into the reservoir toward either the proximal ventricular catheter, the distal peritoneal catheter, or to the ball-in-cone spring valve. 
     While the invention has been described with reference to the preferred embodiment thereof, it will be appreciated by those of ordinary skill in the art that various modifications can be made to the elements and steps of the invention without departing from the spirit and scope of the invention as a whole.