Abstract:
Restoring a blood flow through a blood vessel includes introducing into blood flow an element which has an air and blood impermeable wall, and locating the element in the blood vessel so as to isolate a foreign substance accumulated in a blood vessel to provide an unobstructed blood flow through an interior of the element.

Description:
BACKGROUND OF THE INVENTION 
       [0001]    The present invention relates to a method of and an apparatus for restoring blood flow through a blood vessel. 
         [0002]    Methods and apparatus of this type are known in the art. In known methods and apparatuses stents are inserted into a blood vessel, in which a foreign substance, such as cholesterol is deposited so that the blood vessel is expanded and a sufficient flow cross-section for blood flow is restored. 
         [0003]    It is believed that the existing methods and apparatus can be further improved. 
       SUMMARY OF THE INVENTION 
       [0004]    Accordingly, it is an object of the present invention to provide a method of and an apparatus for restoring blood flow through a blood vessel, which are further improvements of the existing methods and apparatuses. 
         [0005]    In keeping with these objects and with others which will become apparent hereinafter, one feature of the present invention resides, briefly stated, in a method of restoring a blood flow through a blood vessel, comprising the steps of introducing into a blood vessel an element which has an air and blood impermeable wall; and locating said element in the blood vessel so as to isolate a foreign substance accumulated in a blood vessel to provide an unobstructed blood flow through an interior of said element. 
         [0006]    Another feature of the present invention resides in an apparatus for restoring a blood flow through a blood vessel, comprising the steps of introducing into a blood vessel an element which has an air and blood impermeable wall; and locating said element in the blood vessel so as to isolate a foreign substance accumulated in a blood vessel to provide an unobstructed blood flow through an interior of said element. 
         [0007]    The novel features which are considered as characteristic for the present invention are set forth in particular in the appended claims. The invention itself, however, both as to its construction and its method of operation, together with additional objects and advantages thereof, will be best understood from the following description of specific embodiments when read in connection with the accompanying drawings. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0008]      FIG. 1  is a view illustrating a method in accordance with a first embodiment of the present invention; 
           [0009]      FIG. 2  is a view illustrating a method in accordance with a second embodiment of the present invention; 
           [0010]      FIG. 3  is a view illustrating a method in accordance with a third embodiment of the present invention; 
           [0011]      FIG. 4  is a view illustrating a method in accordance with a fourth embodiment of the present invention; 
           [0012]      FIG. 5  is a view illustrating a method in accordance with a fifth embodiment of the present invention; and 
           [0013]      FIG. 6  is a view illustrating a method in accordance with a sixth embodiment of the present invention. 
       
    
    
     DESCRIPTION OF THE PREFERRED EMBODIMENTS 
       [0014]      FIG. 1  shows a first embodiment of the present invention. In this embodiment an element  1  formed as a tubular, curved element is introduced into a blood vessel  2  in which a foreign deposit, for example of cholesterol  3  is formed. One expandable balloon  4  is moved forwardly of the element  1  to expand the blood vessel and to allow the insertion of the tubular element  1 , and another expandable balloon  4  moves behind  1  to maintain the blood vessel expanded. The balloons are operated individually to inflate and deflate. 
         [0015]    The tubular element  1  is composed of a material which is impermeable for air and blood. In view of this, no air or blood supply is delivered to the foreign deposit  3 , and also particles of the foreign deposit  3  cannot migrate into the interior of the blood vessel thus obstructing the latter. 
         [0016]    In the embodiment shown in  FIG. 2 , a blood vessel  11  has a foreign deposit such as cholesterol  12  deposited on its inner wall. An insert  13  with throughgoing openings, such as for example a spiral stent, is introduced into the blood vessel  11 , being led by an inflatable balloon  14  for expanding the vessel downstream. The insert  13  and its opening are covered by a covering material  15  which is impermeable for air and blood and also for material of the foreign deposit. Therefore after the insertion  13  covered by the material  15  the previously formed deposits are reliably isolated from the interior of the blood vessel allowing a blood flow through the blood vessel. They cannot be entrained into the blood flow and also they cannot obtain a supply of air and blood to grow. 
         [0017]    The covering material  15  can be formed as a coating or as a tubular pipe of a biocompatible, for example polymeric material attached to the insert  13  by gluing, laser welding etc. 
         [0018]    In the embodiment shown in  FIG. 3  with a blood vessel  21  containing a deposit  22 , a worm insert  23  penetrates into the deposit  22 . A cutting tool has a body  24 . The worm  23  is rotated by an electric motor  26 . During advance of the device in direction A the foreign deposit is destroyed and during withdrawal of the device in direction B the material of the destroyed deposit is withdrawn through the body  24 . 
         [0019]    In an embodiment shown in  FIG. 4  with the blood vessel  31  containing a deposit  32 , a laser tool  33  is utilized for removing a material of the deposit  32 . At its forward end the laser tool  33  has an expandable gate member  34 . When the laser tool  33  is introduced into the vessel  31 , the gate member  34  expands, its segments of which it is composed are turned out by action of an actuating wire  35  to form a barrier downstream of the laser tool  33 . Then the laser tool destroys the deposit by a laser beam  36 , and the device is pulled out using the gate member  34  as a scoop to move the material of the deposit in the withdrawal direction out of the blood vessel. 
         [0020]    In the embodiment shown in  FIG. 5  with a blood vessel  41  and foreign deposits  42 , the element for restoring a blood flow in the blood vessel is formed as a device  43  which can be an electrical device provided with electrical contacts  44  and  45 . During the operation the electrical contacts  44  and  45  are brought into contacts with the foreign deposit  42  and closed so as to form a closed circuit and to carry out an electrically generated heating of the deposit. This heating destroys the foreign deposit and thereby restores a blood flow through the blood vessel  41 . 
         [0021]    In the embodiment of  FIG. 6  with the blood vessel  51  having a foreign deposit  52 , the element is formed as a filter  53  incorporated in a tube  54 . The filter can be composed of any filtering material having sufficiently small pores which prevent penetration of a foreign deposit material from one side of the filter to another side of the filter thus eliminating a possibility of propagation of the material through the blood vessel to unwanted areas. The filter  53  is provided with sensors formed for example by LEDs, which are designed so that when the filter  53  operates efficiently and allows passage of blood while filtering out the foreign deposit material, one of the LED emits one light, for example a green light, when the filter is at least partially clogged another LED is activated and emits yellow light, and when the filter is completely clogged, the third LED is activated and emits red light. These signals provide a sufficient guidance for keeping the filter and withdrawing it at proper times. 
         [0022]    The filer  53  can have an electronic lock  54  which can be open by a coded signal sent by an authorized person, such as a doctor, to prevent its unauthorized withdrawal from the blood vessel. 
         [0023]    It will be understood that each of the elements described above, or two or more together, may also find a useful application in other types of methods and constructions differing from the type described above. 
         [0024]    While the invention has been illustrated and described as embodied in a method and apparatus for restoring blood flow through a blood vessel, it is not intended to be limited to the details shown, since various modifications and structural changes may be made without departing in any way from the spirit of the present invention. 
         [0025]    Without further analysis, the foregoing will so fully reveal the gist of the present invention that others can, be applying current knowledge, readily adapt it for various applications without omitting features that, from the standpoint of prior art, fairly constitute essential characteristics of the generic or specific aspects of this invention.