Abstract:
The invention provides a nested tubing cannula which comprises outer and inner elongate tubular members, both having a proximal end, a distal end, and a lumen therebetween. The inner tubular member is sealed at its distal end and is nested substantially coaxially within the lumen of the outer tubular member, so that the gap between the inner and the outer tubular member defines a second lumen whereas the first lumen is the lumen of the inner tubular member. A tubular sleeve is disposed coaxially between the inner and outer tubular members. A balloon is mounted on a distal region of the outer tubular member and is in communication with the first lumen. The cannula further comprises a port proximal or distal the balloon occluder and is in communication with the second lumen. Methods for making the devices herein are disclosed.

Description:
This is a continuation of U.S. application Ser. No. 09/093,263, filed Jun. 8, 1998, now abandoned which was a continuation of U.S. application Ser. No. 08/882,418, abandoned, filed Jun. 25, 1997, which was a continuation of Ser. No. 08/469,699, filed Jun. 6, 1995, now U.S. Pat. No. 5,685,312, which was a continuation of U.S. application Ser. No. 08/123,370, filed on Sep. 17, 1993, now U.S. Pat. No. 5,501,227, which was a continuation of U.S. application Ser. No. 07/937,977, filed on Nov. 2, 1992, now U.S. Pat. No. 5,350,395, which was a continuation of U.S. application Ser. No. 07/774,479, filed Oct. 10, 1991, abandoned, which was a continuation of U.S. application Ser. No. 07/548,200 filed Jul. 5, 1990, now U.S. Pat. No. 5,064,273, which was a continuation of U.S. application Ser. No. 07/361,676, filed Jun. 1, 1989, abandoned, which was a continuation of U.S. application Ser. No. 07/117,357 filed Oct. 27, 1987, abandoned, which was a continuation of U.S. application Ser. No. 06/852,197, filed Apr. 15, 1986 abandoned. All of which are expressly incorporated herein by reference in their entirety. 
    
    
     FIELD OF THE INVENTION 
     This invention relates to angioplasty apparatus facilitating rapid exchanges and a method for making rapid exchanges of angioplasty devices. 
     At the present time in practicing angioplasty, it is often necessary to exchange one dilatation catheter for another. In doing so, it has been necessary to utilize long exchange wires having a length of approximately 300 centimeters which typically requires two operators to perform the procedure. During this procedure, it is necessary that the operators communicate with each other which makes the procedure time consuming. In addition, since the exchange wire is so long it often is awkward to handle and for that reason may come in contact with the floor or become contaminated which necessitates removing the entire apparatus being utilized for the angioplasty procedure. There is therefore a need for a new and improved angioplasty apparatus which overcomes such difficulties. 
     SUMMARY OF THE INVENTION 
     In general, it is an object of the present invention to provide an angioplasty apparatus and a method which facilitates rapid exchanges of various types of devices. 
     Another object of the invention is to provide an angioplasty apparatus and method of the above character which greatly facilitates exchanges of dilatation catheters. 
     Another object of the invention is to provide an angioplasty apparatus and method of the above character which can be utilized for the positioning of flexible elongate members. 
     Another object of the invention is to provide an angioplasty apparatus and method of the above character which can be utilized with various types of devices utilizing flexible elongate members. 
     Another object of the invention is to provide an angioplasty apparatus and method in which dye injection and pressure measurements can be made. 
     Additional objects and features of the invention will appear from the following description in which the preferred embodiments are set forth in conjunction with the accompanying drawings. 
    
    
     BRIEF DESCRIPTION OF THE DRAWINGS 
     FIG. 1 is a side elevational view of an angioplasty apparatus incorporating the present invention. 
     FIG. 1A illustrates the ultrasound imaging catheter  26   a  with an ultrasound imaging device extending from its distal portion as labeled rectangular box  16   a.    
     FIGS. 2A,  3 A and  4 A are partial cross sectional views of the shaft, transition and balloon regions of the balloon dilatation catheter utilized in the embodiment of the invention shown in FIG.  1 . 
     FIGS. 2B,  3 B and  4 B are cross sectional views taken along the lines  2 B— 2 B,  3 B— 3 B and  4 B— 4 B of FIGS. 2A,  3 A and  4 A respectively. 
     FIGS. 5A,  6 A and  7 A are cross sectional views corresponding to FIGS. 2A,  3 A and  4 A of another embodiment of a balloon dilatation catheter incorporating the present invention. 
     FIGS. 5B,  6 B and  7 B are cross sectional views taken along the lines  5 B— 5 B,  6 B— 6 B and  7 B— 7 B of FIGS. 5A,  6 A and  7 A respectively. 
     FIGS. 8A and 9 are cross sectional views of the transition and balloon regions of another balloon dilatation catheter incorporating the present invention. 
     FIG. 8B is a cross sectional view taken along the line  8 B— 8 B of FIG.  8 A. 
     FIG. 10 is a side elevational view of a dedicated dye injection/pressure measurement catheter incorporating the present invention. 
     FIG. 11 is a side elevational view of a fiber optic cable incorporating the present invention. 
     FIG. 12 is a side elevational view of a dedicated dye injection/pressure measurement catheter incorporating the present invention and having specific guiding means for facilitating entering acute bends in arterial vessels. 
     FIG. 13 is a side elevational view of a bail out catheter incorporating the present invention. 
     FIG. 14 is a plan view of a holder utilized in connection with the present invention. 
    
    
     DETAILED DESCRIPTION 
     In general, the angioplasty apparatus of the present invention is designed for introduction into the vessel of a patient. It consists of a guiding catheter which is adapted to be inserted into the vessel of the patient. It also consists of a device which is adapted to be inserted into the guiding catheter. The device includes a flexible elongate member; a sleeve is secured to the flexible elongate member near the distal extremity thereof and extends from the distal extremity into a region spaced from the distal extremity of the flexible elongate member. The device also includes a guide wire which is adapted to extend through the sleeve from the distal extremity of the flexible elongate element, through the sleeve and rearwardly of the sleeve alongside of and exteriorally of the flexible elongate element. 
     More particularly as shown in FIGS. 1-4, the angioplasty apparatus  16  for facilitating rapid exchanges of dilatation catheters consists of a conventional guiding catheter  17  which is provided with a rotatable hemostatic adapter  18  mounted on a proximal end and a y or two-arm connector or adapter  19  which is mounted on the rotatable adapter  18 . The y-connector connector  19  is provided with a knurled knob  21  which carries a threaded valve member  22  that carries an O-ring  23  which is adapted to be urged into sealing engagement with a balloon dilatation catheter  26  and a guide wire  27  extending through the y-adapter  19  and through the guiding catheter  17  as shown in FIG.  1 . 
     The balloon dilatation catheter  26  is of a single lumen type and is provided with a flexible elongate tubular member  29  which has a lumen  31  extending therethrough. The flexible tubular member  29  can be formed of a suitable material such as plastic. A Luer-type fitting  32  is mounted on the proximal extremity of the flexible tubular member  29  and is adapted to be connected to a syringe or other type of instrument for introducing a radiographic contrast liquid into the flexible tubular member  29 . A balloon  33  is mounted on the distal extremity of another flexible tubular member  36  also is formed of a suitable material such as plastic. The distal extremity of the balloon  33  is bonded to the distal extremity of the flexible tubular member  36  to form an air-tight and liquid-tight seal with respect to the same. The balloon  33  is coaxial with the tubular member  36  or sleeve as shown in FIG.  4 B. The flexible tubular member  36  is provided with a guide wire lumen  37  through which the guide wire  27  carrying its flexible tip  28  can extend. 
     Means is provided for forming a balloon inflation lumen  41  substantially concentric with the flexible tubular member  36  and extends toward the distal extremity of the flexible tubular member  36 . As can be seen from FIGS. 3B and 4B, the balloon inflation lumen  41  is formed by a flexible tubular member  42  which can be formed integral with the balloon  33 . The flexible tubular member  42  extends into a transition region  44  which overlies the distal extremity of the flexible tubular member  29  so that the lumen  31  therein is in communication with the balloon inflation lumen  41 . As can be seen particularly from FIG. 3A, the flexible tubular member  36  makes a transition and extends out of the tubular member  42  and provides an opening  43 . The proximal extremity of the tubular member  36  overlies the flexible tubular member  31 . The guide wire  27  exits through the opening  43  and extends alongside and exteriorally of the flexible tubular member  29  from the proximal extremity of the flexible tubular member  36  to the proximal extremity of the flexible tubular member  29 . 
     The transition region  44  should be positioned at least approximately 10-15 centimeters from the distal extremity of the balloon dilatation catheter  26 . This is important for two reasons. One is that the transition region be kept at a point where when the balloon dilatation catheter  26  is utilized in a procedure, the transition region remains in the guiding catheter  27  and out of the coronary artery. The spacing from the distal extremity of the dilatation catheter for the transition region is also advantageous in that it permits the person performing the procedure to pull the balloon dilatation catheter  26  out of the guiding catheter  17  until the transition region  44  clears the y-connector  19  so that all of the portion of the guide wire  27  which is exterior of the balloon dilatation catheter  26  is proximal of the y-connector. While this is being done, the operator can then utilize the knurled nut  21  to again close the o-ring to form a hemostatic seal between the y-connector and the balloon dilatation catheter to minimize the loss of blood from the patient. 
     The flexible tubular member  42  can be formed of a suitable material such as a heat shrinkable plastic so that it can be shrunk onto the distal extremity of the flexible tubular member  29  and onto the proximal extremity of the flexible tubular member  36  to form liquid-tight and air-tight seals with respect to the same. From the construction shown it can be seen that the guide wire  27  exits from the balloon dilatation catheter  26  in a region which is relatively close to the distal extremity of the balloon dilatation catheter  26  and extends exteriorally of the balloon dilatation catheter to the proximal extremity of the same. As shown in FIG. 1, the guide wire  27  and the balloon dilatation catheter  26  extend outwardly from the y-connector  19 . 
     A torquer  46  of a conventional construction is secured to the guide wire  27  for rotating the guide wire as hereinafter described. 
     Operation and use of the angioplasty apparatus shown in FIG. 1 may now be briefly described as follows. The guiding catheter  17  is inserted into the coronary artery in a conventional manner. The balloon dilatation catheter is prepared for insertion into the guiding catheter  17  in a conventional manner. The balloon  33  can be inflated outside the body by the use of a balloon flushing tube of the type described in U.S. Pat. No. 4,323,071 and inflated by introducing a radiopaque liquid through the fitting  32  into the lumen  31  and through the lumen  41  into the balloon  33  to flush all of the air in the balloon  33  through the balloon flushing tube to fully inflate the balloon. After the balloon  33  has been inflated, the balloon can be deflated by removing the radiopaque liquid from the balloon. 
     The guide wire  27  is then introduced into the balloon dilatation catheter  26  by a back loading technique. Without the torquer  46  on the guide wire, the proximal extremity of the guide wire  27  is inserted backwardly through the tip of the balloon dilatation catheter through the guide wire lumen  37 . The guide wire is advanced rearwardly by holding the distal extremity of the balloon dilatation catheter in one hand and advancing the guide wire  27  rearwardly with the other hand until the guide wire  27  exits through the opening  43  at the transition region  44  of the dilatation catheter. As soon as the guide wire has cleared the opening  43 , the guide wire can be grasped by the hand and pulled rearwardly paralleling the balloon dilatation catheter  26  until its proximal extremity is near the proximal extremity of the dilatation catheter and so that the distal extremity of the guide wire  27  with its flexible or floppy tip  28  protrudes at least partially from the distal extremity of the balloon dilatation catheter. 
     At this point in time, the O-ring  23  in the y-connector  19  is opened by operation of the knurled knob  21 . The distal extremity of the balloon dilatation catheter  26  having the flexible tip protruding therefrom is then introduced to the y-connector past the opened o-ring  23  and slid down the guiding catheter  17 . The balloon dilatation catheter  26  and the guide wire  27  are grasped between the fingers of a hand and are advanced parallel into the guiding catheter  17 . This procedure is continued until a substantial portion of the balloon dilatation catheter is disposed in the guiding catheter. 
     The torquer  46  now can be attached to the guide wire  27  near the proximal extremity of the same. The guide wire  27  is then advanced ahead of the balloon dilatation catheter until it enters the arterial vessel of the patient. The balloon dilatation catheter  26  is held stable by the fingers of the hand while the guide wire  27  is being advanced. The positioning of the guide wire  27  in the desired arterial vessel can be observed under a fluoroscope by using x-ray techniques well known to those skilled in the art. As is well known to those skilled in the art, the torquer  46  can be utilized for rotating the guide wire  27  to facilitate positioning of the flexible tip  28  in the desired arterial vessel so that the distal extremity of the guide wire can be advanced into the stenosis which it is desired to open or enlarge. 
     As soon as the guide wire  27  is in the desired location, it can be held stationary by two fingers of the hand and at this point in time, the balloon dilatation catheter  26  is advanced over the guide wire until the deflated balloon  33  is across the desired lesion or stenosis. If any difficulty is encountered by the person conducting the procedure in introducing the balloon dilatation catheter so that the balloon  33  resists crossing the lesion or stenosis, the guide wire  27  can be retracted slightly. The person then can observe under the fluoroscope to see that the tip  28  of the guide wire is wiggling in the blood stream indicating that it is free to move in the blood stream. Then the person can grasp both the guide wire and the dilatation catheter in one hand and advance them as a unit so that they can cross the stenosis as a unit. It has been found by utilizing such a procedure, greater pushability can be obtained in advancing the balloon dilatation catheter across the stenosis. In other words, more force can be applied to the balloon to cause it to cross the stenosis or lesion in case the opening therein is very small. 
     After the balloon  33  has crossed the stenosis or lesion, the balloon  33  can be inflated in a conventional manner by introducing a radiopaque contrast liquid through the lumen  31 . After the inflation has occurred and the desired operation has been performed by enlarging the opening in the stenosis, the balloon dilatation catheter  26  can be removed very rapidly by the person performing the procedure by grasping the guide wire  27  by two fingers immediately proximal of the y-connector  19  after the torquer  46  has been removed. The balloon dilatation catheter  26  can be removed in several seconds in comparison with the much longer time required for removing the balloon dilatation catheter utilizing prior art exchange wire procedures. As soon as the balloon dilatation catheter  26  has been removed from the guiding catheter  17 , another injection of radiographic contrast liquid can be introduced through the guiding catheter  17  to observe whether or not the balloon dilatation procedure which has been performed on the lesion or stenosis has in fact opened the lesion or stenosis to the satisfaction of the person performing the procedure. 
     If it is ascertained by the person performing the procedure that additional dilation of the stenosis is desired and that a larger balloon should be inserted into the stenosis, this can be accomplished very rapidly by selecting the desired size of balloon dilatation catheter. 
     As the balloon dilatation catheter  26  is being retracted out of the guiding catheter  17  and as soon as the transition region  44  has cleared the y-adapter  19 , the o-ring  23  can be tightened down to form a seal over the balloon dilatation catheter to minimize the loss of blood of the patient. Thereafter, if desired, the remainder of the balloon dilatation catheter  26  can be removed from the guiding catheter  17  until the proximal extremity of the guide wire passes through the opening  43  and passes through the end of the balloon dilatation catheter  26 . As soon as this has been accomplished, a new balloon dilatation catheter can be loaded onto the guide wire in a rearward direction by introducing the proximal extremity of the guide wire  27  into the tip of the balloon dilatation catheter. As this is being done, the index finger of the hand performing the procedure can be utilized for opening the o-ring by adjusting the knurled knob  21  The guide wire  27  is grasped by the fingers of the hand and the balloon dilatation catheter  26  can be advanced rapidly over the guide wire into the guiding catheter  17  and advanced across the lesion in a manner hereinbefore described with respect to the smaller balloon dilatation catheter which had been utilized. The balloon of the new dilatation catheter can be inflated in the same manner as hereinbefore described. If necessary even another exchange procedure can be readily accomplished in the same manner as hereinbefore described utilizing a still larger balloon dilatation catheter if that turns out to be necessary. 
     It has been found that an exchange utilizing the present angioplasty apparatus can be performed in less than 10 to 15 seconds whereas in the past utilizing a prior art guide wire exchange procedure required an average of approximately two minutes. 
     After the desired amount of dilation of the stenosis or lesion has been accomplished, the balloon dilatation catheter  26  can be removed and thereafter, the guiding catheter  17  can be removed. 
     Another embodiment of an angioplasty apparatus incorporating the present invention is shown in FIGS. 5A and 5B,  6 A and  6 B and  7 A and  7 B in which an additional dye/pressure lumen has been incorporated into the apparatus in order to enable an injection of a distal dye through the balloon dilatation catheter and also to enable the measurement of pressures at the tip of the balloon dilatation catheter. The construction which is utilized is very similar to that shown in the balloon dilatation catheter  26  shown in FIG.  1 . The corresponding parts of the balloon dilatation catheter  26   a  shown in FIGS. 5-7 is very similar to that hereinbefore described and for that reason the corresponding parts have been given the same corresponding numbers with letters being added to the numerals where changes are present in the parts or components. Thus the tubular member  29   a , rather than having a single lumen  31  is provided with dual lumens  31   a  and  31   b  disposed side by side in the shaft region of the balloon dilatation catheter as shown in FIGS. 5A and 5B. In the transition region  44   a , the two lumens  31   a  and  31   b  are still disposed side by side with the lumen  37   a  for the guide wire being disposed above the lumens  31   a  and  31   b . In the balloon region, the lumen  31   a  has been terminated and extends into the balloon lumen  41   a . At the transition region  44   a , the guide wire lumen  37   a  inclines downwardly and sidewise and adjoins the lumen  31   b  through the distal extremity of the balloon dilatation catheter  26   a . The lumen  31   b  extends to the distal extremity of the balloon dilatation catheter. 
     The balloon dilatation catheter which is shown in FIGS. 5-7 can be utilized in the same manner as the balloon dilatation catheter shown in FIG.  1 . It can be seen that the guide wire  27  extends out of the opening  43   a  in the transition region  44   c  and parallels the balloon catheter to its proximal extremity. A balloon dilatation catheter of the type shown in FIGS. 5-7 can be utilized initially in an angioplasty procedure. However, it should be appreciated that if a very small opening is present in the stenosis or lesion, it may be desirable to utilize a balloon dilatation catheter of the type shown in FIG. 1 first because it can be constructed with a smaller diameter than a balloon dilatation catheter of the type shown in FIGS. 5-7 because of the additional lumen which is provided for dye injection and pressure measurements. After a smaller balloon dilatation catheter has been utilized, a balloon dilatation catheter of the type shown in FIGS. 5-7 can be used utilizing the exchange procedure hereinbefore described to make dye injection and/or pressure measurements through the use of the additional lumen  31   b.  It is particularly desirable to make such a pressure measurement before conclusion of the angioplasty procedure to be sure that the proper dilation of the lesion or stenosis has occurred and that there is adequate blood flow through the lesion or stenosis. 
     Still another embodiment of the angioplasty apparatus incorporating the present invention is shown in FIGS. 8A and 8B and shows the transition region of a balloon dilatation catheter  26   b  which incorporates a vent tube  51  which is utilized for venting air from the balloon during inflation of the balloon and before insertion into the patient with radiopaque liquid to ensure that all the air is exhausted from the balloon. As shown in the transition region  44   b  in FIG. 8A, the guide wire  27  extends through an opening  43   b  provided in the transition region and extends through a flexible tubular member  36   b  out the end of the balloon dilatation catheter as shown in FIG. 9. A balloon filling lumen  31   c  is provided by the flexible tubular member  29   b  and terminates in the transition region  44   b  where it opens into the balloon filling lumen  41   b  that opens into the interior of the balloon  33   b.  A relatively short sleeve  52  formed of a suitable material such as plastic is also provided in the transition region  44   b  and as shown in FIG. 8A underlies the flexible tubular member  29   b  and extends from a region forward of the flexible tubular member  42   b  and terminates distally within the balloon inflation lumen  41  as shown in FIG.  8 A. 
     The sleeve  52  is provided with a lumen  53  through which the vent tube  51  extends. The vent tube  51  can be formed of a suitable material such as metal and is also provided with a lumen  54  of a size so that gas can escape therethrough. The proximal extremity of the vent tube  51  is provided with a portion  51   a  which is bent at right angles to the main portion of the vent tube  51  to ensure that the vent tube will be removed from the balloon dilatation catheter  26   b  prior to insertion into the guiding catheter  17 . As shown in FIG. 9, the vent tube  51  extends into the balloon  33  into a region near the distal extremity of the same. 
     Operation of the balloon dilatation catheter  26   b  shown in FIGS. 8A,  8 B and  9  may now be briefly described as follows. With the vent tube  51  in place in the balloon dilatation catheter, radiopaque contrast liquid is introduced through the balloon inflation lumen  31  and through the balloon inflation lumen  41   b  to introduce the liquid into the balloon. As the liquid is introduced into the balloon, any air in the balloon is discharged through the vent tube  51 . Pressure is maintained on the radiopaque contrast liquid introduced into the balloon until droplets  56  of the liquid exit from the proximal extremity of the vent tube  51  which serves to indicate that the balloon has been completely filled with the radiopaque contrast liquid and that all of the air therein has been exhausted therefrom. As soon as this occurs, the vent tube  51  can be withdrawn completely from the balloon dilatation catheter. The sleeve  52  which carries the vent tube collapses upon withdrawal of the vent tube and will remain collapsed to provide a valve to prevent the escape of any additional radiopaque contrast liquid from the balloon  33   b.  The sleeve  52  remains collapsed because when a high pressure is being introduced through the balloon inflation lumen  31   c,  the flexible tubular member  29   b  will force collapsing of the sleeve  52 . Alternatively, when a negative pressure is being applied to the balloon  33   b  as, for example, when the balloon is being deflated, the positive atmospheric pressure on the exterior of the flexible tubular member  42   b  will again cause collapsing of the sleeve  52 . Thus in effect there is provided a double valve system in which positive pressures on the interior will collapse the sleeve and when there is negative internal pressure the positive exterior atmospheric pressure will collapse the sleeve. 
     In all other respects, the balloon dilatation catheter  26   b  can be utilized in the same manner as the balloon dilatation catheters hereinbefore described in connection with exchanges on the guide wire  27 . 
     Still another embodiment of an angioplasty apparatus incorporating the present invention is shown in FIG. 10 in which there is disclosed a dedicated pressure/dye catheter  61 . The pressure/dye catheter  61  consists of an elongate flexible tubular member  62  formed of a suitable material such as plastic which is provided with a pressure dye lumen  63  extending therethrough. The proximal extremity of the tubular member  62  is provided with a Luer-type fitting  64  to which devices having Luer-type fittings can be attached. A sleeve  66  formed of a suitable material such as plastic is secured to the exterior of the flexible tubular member  62  by suitable means such as an adhesive. It is provided with a guide wire lumen  67  extending therethrough. It should be appreciated that the sleeve  66  can be formed integral with the flexible tubular member  62  if desired. The sleeve  66  extends for a distance of at least 10 to 15 centimeters from the distal extremity of the catheter  61  so that the transition region where it terminates at its proximal extremity is be within the guiding catheter  17  so that the transition region does not enter into the arterial vessel of the patient. A guide wire  68  is provided which extends through the guide wire lumen  67 . The guide wire  68  can be of the same type as the guide wire  27 . It is inserted into the sleeve  66  by taking the proximal extremity of the guide wire which is relatively stiff and inserting it into the distal extremity of the sleeve and then pushing it backwardly or rearwardly through the sleeve until it clears the opening  69  at the proximal extremity of the sleeve  66 . The guide wire  68  is then pulled so that it extends in a direction parallel to the flexible tubular member  62  into a region near the proximal extremity of the tubular member  62 . 
     It can be readily seen from the foregoing description that the pressure/dye catheter  61  can be readily introduced into a guiding catheter  17  and that the distal extremity of the pressure/dye catheter can be positioned in a desired location in the arterial vessel by utilizing the guide wire  68  to position the same. It also should be appreciated that a torquer of the type hereinbefore described such as the torquer  46  can be utilized on the proximal extremity of the guide wire  68  to cause rotational movement of the guide wire to facilitate positioning of the guide wire in the desired arterial vessel and to thereafter have the tubular member  62  follow the same. The desired picture and/or dye measurements can then be made by utilizing the lumen  63  provided in the tubular member  62 . As can be seen from FIG. 10 the distal extremity of the tubular member  62  can be slanted and rounded as shown to facilitate entry into the stenosis in the arterial vessel. This is desirable because of the eccentricity created by the addition of the sleeve  66 . 
     Another embodiment of an angioplasty apparatus is shown in FIG.  11  and takes the form of a fiber optic device  71 . An encased fiber optic bundle  72  which is generally circular in cross-section is provided. A sleeve  73  of the type hereinbefore described formed of a suitable material such as plastic is secured to the distal extremity of the fiber optic bundle  72  which is adapted to receive a guide wire  74 . As in the previous embodiments, the sleeve  73  extends from the distal extremity for a distance of approximately 10 to 15 centimeters after which the guide wire exits from the sleeve and extends alongside and exteriorally of the fiber optic bundle  72  for substantially the entire length of the fiber optic bundle. As with the previous devices, the guide wire  74  is threaded into the sleeve by taking the proximal extremity or stiff end of the guide wire and inserting it at the distal extremity of the sleeve  73  and pushing it from the rear towards the forward extremity of the sleeve. The fiber optic device  71  can then be inserted into a guiding catheter  17  and advanced to the desired location through the use of the guide wire. The fiber optic bundle then can be utilized for angioscopy for looking directly at the blood vessel or alternatively, for delivering energy to plaque in the blood vessel to perform laser angioplasty. It should be appreciated that steerable systems can be utilized for directing the distal extremity of the fiber optic bundle if that is desired. 
     It should be appreciated that the concept of using a relatively short sleeve extending from the distal extremity of the device to a region approximately 10 to 15 centimeters to the rear and then having the guide wire extend externally of the device is applicable for a number of medical devices as well as other applications. For example, ultrasonic catheters  26   a  for imaging ultrasound and for measurement of Doppler velocity  16   a  can be utilized to provide various types of dedicated devices having the guide sleeve with the guide wire therein for facilitating positioning of the same in arterial vessels. The apparatus of the present invention is particularly useful in devices where multiple reentries are required in order to complete the procedure. 
     In FIG. 12, there is disclosed another embodiment of an angioplasty apparatus to provide a pressure dye catheter  76  having additional steering capabilities. It consists of a flexible tubular member  77  formed of a suitable material such as plastic which is provided with a lumen  78  extending through a slanted and curved end. A Luer-type fitting  79  is provided on the proximal extremity. A sleeve  81  formed of a suitable material such as plastic is secured to the distal extremity of the flexible elongate member  77 . The sleeve is provided with a curved portion  81   a  which extends slightly beyond the distal extremity of the flexible elongate member  77  and curves over the end of the flexible elongate member  77 . The guide wire  82  extends through the sleeve  81  as shown. The catheter shown in FIG. 12 can be utilized in situations where there is an acute bend in the arterial vessel. By using the catheter shown in FIG. 11, the guide wire can be directed into the acute bend by rotation of the catheter  76  to help direct the guide wire into the acute bend. After the acute bend has been negotiated by the guide wire, the distal extremity of the catheter can follow the guide wire and negotiate the acute bend. The desired pressure and/or dye measurements can then be made. If by chance a guide wire should enter the wrong vessel, the guide wire can be retracted into the sleeve and then the catheter itself can be reoriented to have the distal extremity of the sleeve  81  directed into the proper region so that the guide wire will enter the proper arterial vessel. The catheter  76  shown in FIG. 12 can be introduced into the guiding catheter  17  in the same manner as the other catheters hereinbefore described. 
     Still another embodiment of the angioplasty apparatus of the present invention is shown in FIG. 13 in the form of  86  bailout catheter  86 . The bailout catheter  86  consists of a flexible tubular member  87  formed of a suitable material such as plastic which is provided with a lumen  88  extending therethrough. A Luer-type fitting  89  is secured to the proximal extremity of the tubular member  87 . The distal portion of the tubular member  87  is provided with two sets  91  and  92  of holes  93  which are spaced circumferentially and apart longitudinally of the tubular member. A sleeve  96  formed of a suitable material such as plastic is secured to the distal extremity of the tubular member  87  and extends from the distal extremity of the tubular member  87  into a region 10 to 15 centimeters from the distal extremity and is adapted to receive a guide wire  97  which extends through the same. The guide wire  97  is inserted into the sleeve by taking the proximal extremity of the guide wire and inserting it into the distal extremity of the sleeve and pushing it rearwardly into the sleeve until it exits from the sleeve. The guide wire  97  is then pulled in a direction generally parallel to the flexible tubular member  87  until it is adjacent the fitting  89 . 
     The bailout catheter  86  is utilized in situations where an obstruction has occurred in a blood vessel and stops the flow of blood. In order to reestablish the flow of blood, the bailout device is inserted into the guiding catheter  17 . If a guide wire is already in place, the bailout device can be placed on the guide wire by introducing the proximal extremity of the guide wire into the sleeve and then pushing the bailout catheter on the guide wire into the guiding catheter  17  until it passes through the obstruction in the arterial vessel. The distal extremity of the bailout device is so positioned so that the obstruction is disposed between the two sets of holes  91  and  92 . When the bailout catheter is positioned, blood can still flow through the holes  93  past the obstruction which is held out of the way by the bailout catheter. 
     Thus it can be seen that the same principle utilizing a guide tube and an external guide wire passing through the guide tube can be utilized for positioning the bailout device. As pointed out previously, the bailout device can be utilized for positioning other types of devices in arterial vessel, as for example, atherectomy devices particularly where multiple re-entries or reintroductions of the devices are required. 
     In FIG. 14 there is disclosed additional angioplasty apparatus in which a holder  101  is provided which serves as a support structure for a y-type connector  19  of the type hereinbefore described in conjunction with the angioplasty apparatus shown in FIG.  1 . The holder  101  consists of a rectangular member  102  which is generally planar. The member  102  can be formed of a suitable material such as plastic and is provided with a plurality of rectangular openings  103  extending longitudinally of the same to lighten the same. Posts  104  are provided on the forward extremity of the member  102  and are adapted to receive the y-type connector  19  and to hold it in place on the member  102 . When positioned in the posts  104 , the knurled knob  21  extends into one of the openings  103  so that it can be readily operated. A block  107  is carried by the other end of the member  102  and, if desired, can be formed integral therewith. The block is provided with a plurality of spaced apart slots  108  which are adapted to frictionally engage and receive the guide wire  27 . The friction block  107  should be positioned a suitable distance as, for example, 15 to 20 centimeters from the o-ring carried by the y-connector  19 . 
     Use of the holder  101  shown in FIG. 14 may now be briefly described as follows. The holder  101  can be placed on the operating table near the region where the guiding catheter  17  has been inserted into the patient, as for example, in a femoral artery in the leg of a patient. After the guide wire has been inserted into the guiding catheter, the proximal end or, in other words, the stiff end of the guide wire can be placed in the friction clamp  108 . When it is desired to utilize a dilatation catheter, the end of the guide wire which has been positioned in the clamp can be lifted out of the slot  108  and inserted into the sleeve carried by the distal extremity of the dilatation catheter by taking the proximal end and advancing it from the tip rearwardly through the sleeve. As soon as the guide wire has been introduced through the sleeve, the proximal extremity of the guide wire can be repositioned in the slot  108 . Thereafter, the dilatation catheter can be advanced independently without the operator needing to pay any attention to the guide wire which is held in the desired position by the holder  101 . Similarly, the holder can be utilized to keep the guide wire in place while the dilatation catheter is being briskly withdrawn. 
     More than one of the slots  108  has been provided in the holder  101  in order to make it possible to accommodate two wire or two balloon dilatation catheters in which one of the other slots  108  can be utilized for accommodating the additional guide wire. This prevents the guide wires from becoming entangled with each other. 
     It is apparent from the foregoing that there has been provided an angioplasty apparatus which greatly facilitates the exchange of devices which utilize flexible elongate elements as a part thereof. Rapid exchanges are possible with only one person being necessary to make the exchanges. The need for long exchange wires has been eliminated. One device can be readily substituted for another utilizing the same guide wire which has already been positioned. It can be seen from the foregoing that a relatively simple and expedient solution has been provided which eliminates the need for long exchange wires and the danger of those exchange wires becoming contaminated. 
     Although the present invention has been described principally in conjunction with catheters having coaxial lumens, it should be appreciated that the invention is as applicable, if not more applicable, to catheters having side-by-side lumens.