Abstract:
A kit for performing angioplasty or stenting in a blood vessel, composed of at least two components. One of the components includes a first catheter providing a blood bypass flow path and carrying a blocking balloon and a blood vessel dilation device. Another one of the components includes a second catheter having an imperforate wall enclosing an axial lumen and having an open distal end, a hollow tube surrounding, and movable longitudinally with respect to, the second catheter, and a second blocking balloon carried by the hollow tube.

Description:
BACKGROUND OF THE INVENTION 
   The present invention relates to the treatment of obstructions in the arteries, and particularly the coronary arteries, and vein grafts of a patient. 
   There is a growing appreciation for the value of treating arterial obstructions by angioplasty and/or stenting, on an emergency basis. Numerous studies show that emergency angioplasty can save lives if done quickly, and in the current state of the art, this requires an experienced team of doctors, nurses and technicians. It also requires the widespread availability of suitable equipment, which, in the present state of the art, is relatively sophisticated and costly. 
   BRIEF SUMMARY OF THE INVENTION 
   The present invention seeks to alleviate these limitations by providing a kit composed of a relatively small number of relatively simple components that are capable of being used in various combinations and/or sequences to successfully treat substantially all arterial obstructions that require urgent treatment. 
   This is achieved by the provision of a kit for performing an angioplasty, stenting, or clot removal procedure in a blood vessel, and for removing thrombus prior to this procedure, especially in emergency situations. The kit is composed of: 
   a first component comprising:
         a first catheter having a wall enclosing an axial lumen, the first catheter having a distal end and the wall having a substantially circularly cylindrical inner surface and being provided with at least one blood inlet opening spaced from the distal end, at least one blood outlet opening in proximity to the distal end, a fluid delivery and suction opening located between the blood inlet and outlet openings, the blood inlet opening and blood outlet opening communicating with the axial lumen and forming with the axial lumen a blood bypass flow path, and a fluid delivery and suction lumen communicating with the fluid delivery and suction opening;   a first blocking balloon carried by the first catheter at a location between the blood inlet opening and the blood outlet opening; and   an expandable blood vessel dilation device carried by the first catheter at a location between the blood inlet opening and the blocking balloon;       

   a second component composed of a guide wire having a distal and provided with a blocking structure at or near the distal end; and 
   a third component comprising:
         a second catheter having a thin, imperforate wall enclosing an axial lumen, the second catheter having an open distal end;   a hollow tube dimensioned to surround, and to be movable longitudinally with respect to, the second catheter; and   a second blocking balloon carried by the hollow tube.       

   The second component is intended to be used in conjunction with the first component. 
   The third component will be used in a first step to remove any clot that may be present. The second catheter has an outer diameter that is sufficiently small to allow it to move past even substantial clots. 
   The first component will then be used to perform angioplasty and/or stenting. 

   
     BRIEF DESCRIPTION OF THE DRAWINGS 
       FIG. 1  is a side elevational, cross-sectional view of a preferred embodiment of the first component of a kit according to the invention. 
       FIGS. 2 and 3  are cross-sectional views taken along lines  2 - 2  and  3 - 3  of  FIG. 1 . 
       FIG. 4  is a detail view of an additional element of the first component. 
       FIG. 5  is a cross-sectional view of a preferred embodiment of the third component of a kit according to the invention. 
   

   DETAILED DESCRIPTION OF THE INVENTION 
   A first component of a kit according to the invention is shown in  FIGS. 1-3  and is composed essentially of a dilatation and embolic blocking catheter  12 . 
   Catheter  12  is a hollow body provided along its axis with a blood bypass flow lumen  22 . The wall of catheter  12  is formed to contain three lumens: a proximal balloon inflation lumen  26 ; a distal balloon inflation lumen  28 ; and a fluid delivery and suction lumen  30 . Lumens  26  and  28  can each have a circular cross section, while lumen  30  is preferably elongated, as shown, in the circumferential direction to provide an enlarge flow cross section. 
   Lumen  22  can, but need not, extend the full length of catheter  12  and has a small diameter opening at the distal end thereof for passage of a guide wire  32  that serves to guide catheter  12  to a desired treatment site. Guide wire  32  may be a hollow tube whose distal end is used as a pressure sensor in communication with a pressure monitoring device connected to the proximal end of guide wire  32 . 
   Preferably, the opening at the distal end of catheter  12  is made only slightly larger in diameter than guide wire  32  to allow more accurate guidance of catheter  12 . 
   Catheter  12  is provided with a plurality of blood flow inlet openings  36  and a plurality of blood flow outlet openings  38 , each set of openings  36 ,  38  being distributed to the extent possible circumferentially around the outer lateral wall of catheter  12 . Openings  36  and  38  extend through the lateral wall of catheter  12  into communication with lumen  22 . 
   If lumen  22  does not extend through the full length of catheter  12 , the proximal end of lumen  22  must be located at a point upstream of openings  36 , while the distal end of lumen  22  must be located downstream of openings  38 . A separate guide wire lumen may be provided over the entire length of catheter  12 . Such a catheter is disclosed in copending U.S. application Ser. No. 10/118,332, filed by T. Anthony Don Michael on Apr. 9, 2002, the disclosure of which is incorporated herein by reference. 
   A balloon, or a stent deployment sleeve or sheath,  40  and a balloon  42  are carried on the outer surface of catheter  12  at locations between openings  36  and  38 . The blood bypass flow path defined by lumen  22  should extend at least across balloon  42  because that balloon remains inflated for a longer period of time, of the order of several minutes, than does balloon  40 , which usually remains inflated for a period of the order of a few seconds. 
   According to preferred embodiments of the invention, balloon  40  is a low compliance angioplasty balloon, sheath, or sleeve, and balloon  42  is a high compliance blocking balloon. In further accordance with the invention, balloon  40  may carry a stent  46  that is to be expanded and deployed against the inner wall of a body passage to be treated. Balloon or sleeve  40  communicates via an opening  48  in the wall of catheter  12  with inflation lumen  26  and balloon  42  communicates via another opening (not shown) in the wall of catheter  12  with inflation lumen  28 . 
   According to common practice in the field, catheter  12  can also be provided with circular radiopaque bands adjacent to the proximal and distal edges of both balloons to assist in proper positioning of the catheter. In practical embodiments of the invention, catheter  12  can have a size of 3 to 4 Fr (nFr=n/3 mm). 
   According to another feature of the invention, catheter  12  can taper and have a gradually decreasing wall thickness, as shown, in the region between balloon  42  and the distal end of the catheter. The tapering and gradually decreasing wall thickness will give catheter  12  greater flexibility, and thus an improved ability to negotiate bends and traverse severe obstructions in the blood vessel during insertion. 
   The second component is a guide wire  132 , shown in  FIG. 4 . Guide wire  132  has, at its distal end, an enlargement  134 , which may be spherical or, as shown, frustoconical. Enlargement  134  is dimensioned to substantially completely block the tapered distal end of lumen  22 , at a point just upstream of outlet openings  38 , while being small enough to slide along lumen  22  in order to allow introduction and positioning of wire  132 . Preferably, enlargement  134  is dimensioned to provide a gap between itself and the inner wall of catheter  12  that allows some blood flow through lumen  22  when enlargement  134  is positioned upstream of the tapered distal end of catheter  12 . 
   Catheter  12  is associated with a guiding catheter  56  having an inner diameter larger than the outer diameter of stent  46  prior to deployment. Guiding catheter  56  is given a wall thickness sufficient to prevent the catheter from being compressed by the blood vessel wall. 
   Treatment lumen  30  communicates with the region surrounding catheter  12  and between balloons  40  and  42  via one or more openings  60  in the wall of catheter  12 . Lumen  30  is further in communication with a conventional system  62  that will be located outside of the patient&#39;s body and that is equipped to supply a treatment fluid or flushing fluid and/or to apply suction through lumen  30 . The treatment fluid may contain medication or genetic agents, such as stem cells, to aid repair of damage that may be caused to the blood vessel wall by the removal of clot and/or an angioplasty or stenting procedure. 
   A third component of the kit according to the invention is shown in  FIG. 5  and is composed of a second catheter  212  and a hollow tube  214 . Catheter  212  is constituted by an imperforate thin wall that is not provided with any blood flow inlet or outlet openings. Catheter  212  is open at its distal end to allow passage of a guide wire  32  not provided with a bead. Catheter  212  may have an outer diameter of 1-2 Fr, preferably 1.5 Fr, and a wall thickness of 0.127 mm. 
   Catheter  212  may be coupled to system  62 , described above. 
   Tube  214  carries a high compliance blocking balloon  242  and is provided with a balloon inflation lumen  228  for supplying inflation fluid to balloon  242 . Balloon  242  and lumen  228  may correspond structurally and functionally to balloon  42  and lumen  28  of the component shown in  FIGS. 1-3 . 
   In order to perform a treatment procedure using the kit according the invention, a guide wire and guiding catheter  56 , shown in  FIG. 1 , are inserted according to conventional procedures until the distal end of guiding catheter  56  is brought to a location a short distance upstream, with respect to the direction of blood flow, of the obstruction. 
   Then, if conventional diagnostic procedures indicate the presence of clot, the elements of the third component are introduced over the guide wire and through the guiding catheter  56  to a location just upstream of the obstruction. Balloon  242  is inflated to prevent the flow of clot debris in the upstream direction and to anchor tube  214  in position during the procedure, and suction is performed through catheter  212 , by operation of system  62 , to remove as much of the clot as possible. During this removal step, catheter  212  may be moved forward and back along the axis of tube  214  to aid the removal operation. Suction may alternate with the delivery of a treatment fluid, such as a suitable medication or genetic agents, such as stem cells, supplied by system  62  and conducted through catheter  212 . If clot is not present, this procedure with the third component can be omitted. 
   Then, the extent of the remaining obstruction is evaluated in a conventional manner, as by injecting a contrast solution into the artery through guiding catheter  56 . 
   Then, an angioplasty and/or stenting procedure will be performed with the component shown in  FIGS. 1-3 . 
   According to this procedure, after withdrawal of components  212  and  214 , catheter  12  is introduced over guide wire  32  and through guiding catheter  56  to a point at which balloon  42  is downstream of the obstruction and the dilation elements  40  and  46  are in line with the obstruction. Guide wire  32  is withdrawn, at least to a point upstream of openings  36 , to enlarge the flow cross section of lumen  22  and balloon  42  is inflated to block blood flow through the blood vessel around catheter  12 . 
   Then, guide wire  132  is introduced into lumen  22  to bring enlargement  134  into the tapered portion of lumen  22 , just upstream of openings  38 , to block blood flow through lumen  22 . 
   Immediately thereafter, balloon or sheath  40  is expanded in order to dilate the obstruction, if a stent is not used, or to expand stent  46  against the obstruction, and thus dilate the obstruction. Debris released from the obstruction will be prevented from flowing downstream through lumen  22  due to blockage of lumen  22  by enlargement  134 . 
   Then, balloon  40  can be deflated, leaving stent  46  in place, and suction can be applied by system  62  through lumen  30  to withdraw debris. During this operation, the application of suction can alternate with the delivery, also from system  62  and through lumen  30 , of a flushing liquid and/or a treatment fluid, such as a gene therapy agent and/or stem cells, that aids the growth of normal tissue in the portion of the blood vessel that was damaged by the angioplasty treatment. Alternatively, or in addition, a treatment fluid can be introduced or suction can be performed through guiding catheter  56 . 
   Finally, balloon  42  is deflated and catheter  12  and guide wire  132  are withdrawn. 
   Thereafter, catheter  212  and tube  214  of the second component may be reintroduced and balloon  242  inflated to allow delivery of a quantity of contrast solution, through catheter  212  or tube  214 , in order to allow observation of the angioplasty or stenting result. Then, balloon  242  would be deflated and catheter  212  and tube  214  withdrawn, followed by withdrawal of guide wire  32  and of the guiding catheter  56 . If necessary, catheter  12  would be re-introduced to form a further procedure. 
   In further accordance with the invention, the first component can be used to apply the treatment fluid to the blood vessel wall, either as an incident to an angioplasty or stenting procedure and/or clot removal procedure, or as an independent operation. For this purpose, catheter  12  may already be at the desired treatment location, which may be the location of a previous angioplasty or stenting procedure, or may be brought to that location. Balloon  42  is, or may already be, expanded to its blocking state. Balloon  40  may be placed in a partially inflated state, by appropriate control of the inflation pressure applied to balloon  40 , so as to not apply a dilation force to the blood vessel wall or to the stent. In this state, balloon  40  may impede, but not fully block, blood flow around catheter  12 . Guide wire  132  will be inserted into lumen  22  in order for enlargement  134  to block fluid flow through lumen  22 . Then treatment fluid is introduced to the treatment location from system  62  through lumen  30  and opening  60 . With enlargement  134  in place, the flow of both blood and treatment fluid through lumen  22  will be blocked. After an appropriate treatment time, suction may be applied by system  62  to withdraw any remaining treatment fluid. The steps of introducing treatment fluid and suctioning can be repeated if necessary. Upon completion of this treatment, balloons  40  and  42  are deflated and catheter  12  is withdrawn. 
   After all treatments have been completed, guiding catheter  56  is withdrawn from the blood vessel. 
   While the description above refers to particular embodiments of the present invention, it will be understood that many modifications may be made without departing from the spirit thereof. The accompanying claims are intended to cover such modifications as would fall within the true scope and spirit of the present invention. 
   The presently disclosed embodiments are therefore to be considered in all respects as illustrative and not restrictive, the scope of the invention being indicated by the appended claims, rather than the foregoing description, and all changes which come within the meaning and range of equivalency of the claims are therefore intended to be embraced therein.