UNIVERSAL MODE VASCULAR CATHETER SYSTEM

Abstract: An angioplasty catheter (10) comprising a catheter shaft (12) having a proximal portion and a distal end, an angioplasty balloon (24) attached to the shaft at the distal end, guidewire lumen extending through the shaft and through the balloon for receiving a steerable guidewire, wherein the guidewire lumen has a proximal opening (32) located at a point normally outside of the patient for insertion of a guidewire into the lumen, and a side port (34) adapted to permit passage of a guidewire into the lumen through the outside wall of the guidewire lumen, the side port (34) located distally of the proximal opening and guidewire removing means (40) in the outside wall of the guidewire lumen, extending from the proximal opening (32) to the side port (34) for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen through the outside wall of the guidewire lumen. Also disclosed is a removable "Y" connector.

Description: UNIVERSAL MODE VASCULAR CATHETER SYSTEM FIELD OF THE INVENTION This invention relates to vascular catheters (such as angioplasty catheters) specially adapted for rapid exchange of both the guidewire and the catheter during use. It also relates to the method of using those catheters. BACKGROUND OF THE INVENTION Percutaneous transluminal coronary angioplasty (PTCA) has emerged as the major viable present alternative to bypass surgery for revascularization of stenotic and occluded coronary arteries. Although transluminal angioplasty has application in peripheral artery disease, it is most widely used in the treatment of coronary artery disease. Unlike bypass surgery, percutaneous angioplasty does not require general anesthesia, cutting of the chest wall, extracorporeal perfusion, or transfusion of blood. Percutaneous coronary angioplasty is not only less invasive and less traumatic to the patient, it is also less expensive because the angioplasty patient will have a shorter hospital stay and shorter post-procedure recovery time. Percutaneous transluminal angioplasty is performed by making a skin puncture with a specially-designed needle in one of the groins, and then introducing a guiding catheter (typically 8 or 9 French size) into the aorta and coronary artery orifice. A smaller caliber catheter which has a built-in inflatable and deflatable balloon of predetermined size and diameter is passed through the guiding catheter which is positioned in the opening of a target artery. This balloon catheter (with the balloon totally deflated by negative pressure) is advanced inside the target artery toward the point of obstruction that needs to be dilated. The guidewire plays an essential role in leading the balloon catheter to the target coronary artery in safety and non-traumatic fashion. With the balloon portion of the catheter properly positioned inside the obstructed segment of the artery, under X-ray fluoroscopic observation, the balloon is inflated by injecting contrast media mixed with saline at a pressure sufficient to overcome the resistance of the arteriosclerotic plaque of the obstructed segment. By inflating the balloon in the stenosis multiple times over a period of between 10-30 seconds and one or two minutes (allowing blood flow between inflations), the desired dilation of the obstructed segment of the artery can be achieved. When the desired results have been obtained by balloon inflations, the guiding catheter, the balloon catheter (with the balloon completely deflated with negative pressure) and the guidewire are withdrawn from the artery and the patient and the procedure is successfully terminated. The size and diameter of the balloon to be used in a transluminal angioplasty should be approximately matched to the size and native diameter of the obstructed segment of the artery to be dilated. If the balloon size and diameter is smaller than the native artery, the results of balloon angioplasty are suboptimal, requiring a second dilation with a larger-sized balloon, and if balloon size is too large for the native artery, complications may occur due to arterial wall damage. During the angioplasty procedure, a guidewire is first advanced into the desired location, after which the angioplasty catheter is advanced over the guidewire. It is sometimes necessary to replace (or exchange) either the guidewire or the balloon catheter during the procedure. If the balloon is undersized, for example, the catheter must be withdrawn and replaced with a larger balloon catheter in order to permit adequate dilatation of the lesion. With conventional over-the-wire catheters, in which the guidewire lumen extends the entire length of the catheter shaft, a guidewire extension (e.g., 145 cm long) must first be attached to the regular guidewire (e.g. 175 cm long) being used outside the patient before the catheter is withdrawn. This permits the distal end of guidewire to be held in position while the catheter is removed and a new catheter is exchanged. Usually, two to three operators are needed to effect such a catheter exchange. The catheter disclosed in U.S. Patent No. 4,762,129 avoids the necessity for extending the guidewire or exchange guidewire (e.g. 300 cm in length) by having a short guidewire lumen that extends substantially only through the distal end of the catheter. This type of catheter is referred to herein as a rapid-exchange catheter. Thus, the guidewire is outside the catheter shaft for much of the catheter length, and is inside the catheter at only the distal end. The catheter can be exchanged without extending the 175 cm regular guidewire, and the exchange can be effected by one or two operators. However, this catheter has a serious drawback of not being able to permit ready exchange of guidewires. In clinical practice, the need for guidewire exchange is more common. Conventional over-the-wire angioplasty catheters, with a guidewire lumen extending their entire length, permit simple guidewire exchange. During angioplasty procedures, the guidewire tip may become damaged, may be needed of a different type of guidewire or may need to be reshaped to complement the patient's vasculature. The guidewire exchange procedure is readily accomplished with such a conventional over-the-wire catheter. However, with the rapid-exchange type catheter of U.S. Patent No. 4,762,129, guidewire exchange requires complete removal and reinsertion of both the guidewire and the angioplasty catheter; thus, defeating the original goal of expedient advantage of the rapid- exchange catheter. Another disadvantage of the rapid-exchange catheter is back bleeding. While the guidewire is being manipulated to select the target vessel or to cross the culprit lesion, the Tuehy-Borst adapter must be loosened. This, in turn, permits backbleeding to occur. Accordingly, there is a need for an angioplasty catheter that permits rapid-exchange of both the catheter and the guidewire. There is also a need for a catheter that will permit the user to select the mode of usage between the rapid-exchange and the over-the-wire systems. SUMMARY OF THE INVENTION In accordance with one aspect of the present invention, there is provided an angioplasty catheter comprising a catheter shaft having a proximal portion and a distal end, an angioplasty balloon attached to the shaft at the distal end, a balloon inflation lumen extending through the shaft and communicating with the interior of the balloon, a guidewire lumen extending through the shaft and through the balloon for receiving a steerable guidewire, the guidewire lumen having an outside wall, wherein the guidewire lumen has a proximal opening located at a point normally outside of the patient during use of the catheter for insertion of a guidewire into the lumen, and a side port adapted to permit passage of a guidewire into the lumen through the outside wall of the guidewire lumen, the side port located distally of the proximal opening and at a point normally inside of the patient during use, and guidewire removing means in the outside wall of the guidewire lumen extending from the proximal opening to the side port for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. In one embodiment, the side port is located adjacent to and proximally of the balloon, preferably within about 35 cm of the balloon. One embodiment of the guidewire removing means is a slit through the outside wall of the catheter shaft. This slit may be continuous from the proximal opening to the side port, or may be discontinuous, forming a perforated line from the proximal opening to the side port. In another embodiment, the guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. One variation of the invention provides a second side port communicating with the interior of the guidewire lumen. Another provides a perfusion opening communicating with the interior of the guidewire lumen, the perfusion opening located between the side port and the balloon. Still another embodiment includes a "Y" connector at the proximal opening having an axial portion through which the balloon inflation lumen extends and a side portion through which the guidewire may be inserted into the guidewire lumen, wherein at least a portion of the connector can be removed from the catheter shaft to permit a guidewire extending through the connector and into the guidewire lumen to be removed through the guidewire removing means. The connector is advantageously adapted to be separated longitudinally and at least a portion thereof removed from the catheter shaft. In one variation, the connector comprises two longitudinally separable portions having first and second longitudinal sides on different sides of the catheter shaft, the portions being hingedly joined at the first longitudinal side and separably joined at the second longitudinal side. Another embodiment of the present invention comprises an intravascular catheter comprising a catheter shaft having a proximal end and a distal end, wherein a portion of the catheter including the distal end is normally inside a patient during use and the proximal end is normally outside the patient or outside the guiding catheter, a guidewire lumen extending through the shaft for receiving a steerable guidewire, wherein the guidewire lumen has and outside wall, and a proximal opening at the proximal end of the shaft for insertion of a guidewire into the lumen, and means formed in the outside wall of the guidewire lumen extending distally from the proximal opening to a point normally inside the patient during use of the catheter for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. The guidewire removing means may be a slit, fully formed or inchoate. The catheter preferably includes a side port through the outside wall of the guidewire lumen for passage of a guidewire into the lumen through the side of the catheter shaft, the side port located distally of the proximal opening and normally inside of a patient during use of the catheter. In one embodiment of the catheter, the guidewire removing means is a slit and the slit is continuous from the proximal opening to the side port. In another, the guidewire removing means is a slit and the slit is discontinuous, forming a perforated line from the proximal opening to the side port. In still another embodiment, the guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. According to one modification, the catheter may further comprise a second side port communicating with the interior of the guidewire lumen. The present invention also includes a catheter for use in an animal body with a guidewire, comprising a catheter shaft having a proximal end and a distal end with at least two lumens extending therethrough, and a "Y" connector surrounding at least a portion of the proximal end of the catheter shaft and having at least two arms, one arm providing an access channel into one of the lumens and another arm providing an access channel into another of the lumens, wherein the T connector has at least two segments joined together in a separable manner along a longitudinal line so that upon separation of the segments, the Υ" connector no longer surrounds the portion of the proximal end of the catheter shaft. In one embodiment, upon separation of the segments, one of the segments is completely removable from the catheter shaft. In another embodiment, upon separation of the segments, the connector is completely removable from the catheter shaft in such a manner that an elongate object extending through one arm of the connector into a lumen of the catheter shaft can remain in the lumen during such removal of the connector. The invention further includes a method of removing a catheter during a procedure involving vascular catheterization, comprising the steps of providing a catheter of the type described above having a guidewire passing through the guidewire lumen from the proximal opening to the distal opening thereof and positioning the catheter in a patient with the proximal end of the guidewire extending out of the proximal opening, holding the proximal end of the guidewire to maintain the positioning of the guidewire in the patient while removing the catheter from the patient by moving the guidewire laterally out of the guidewire lumen through the guidewire removing means until the entire catheter is outside the patient and outside the guiding catheter and a portion of the guidewire is exposed at the distal end of the catheter, and then holding the exposed portion of the guidewire and removing the catheter off of the proximal end of the guidewire. The method may also include inserting another catheter, with the guidewire in the guidewire lumen at the distal portion of the catheter and either remaining in the guidewire lumen for the entire length of the catheter that is inside the patient during use, or extending out through the side of the catheter and running parallel to the catheter proximal of the distal portion of the catheter. The present invention also includes a multi-lumen vascular catheter for use with a guidewire, comprising a longitudinally extending catheter shaft having a proximal end and a distal end and having at least first and second lumens extending distally from the proximal end, each of the lumens having a proximal opening, wherein the first lumen is adapted to receive a guidewire, and a first connector at the proximal end of the catheter providing a first channel communicating with the interior of the first lumen for insertion of a guidewire therethrough, the connector including means for permitting a guidewire extending longitudinally through the first channel into the first lumen to be moved laterally out of the first channel through the first connector. In one embodiment, the first connector is adapted to separate into first and second parts to permit the lateral movement of the guidewire out of the first channel through the first connector. The catheter may include a second connector at the proximal end of the catheter providing a second channel communicating with the interior of the second lumen. The second connector may be located distally or proximally of the first connector. In one embodiment, the first and second connectors are joined together in the form of a "YΛ The catheter may further include guidewire removing means in the outside wall of the first lumen extending distally from the proximal opening for permitting a guidewire in the first lumen to be moved laterally from the first lumen though the outside wall of the guidewire lumen. The guidewire removing means can be a slit, a weakened area of the outside wall of the guidewire lumen, or a removable strip. The slit may be continuous from the proximal opening to a point normally inside the patient during use, or may be discontinuous (e.g., a perforated line). The guidewire removing means can be a weakened area of the wall of the first lumen adapted to be severed for removal of the guidewire therethrough. The catheter may also include a side port located at a point normally inside the patient during use, the side port extending through the outside wall of the guidewire lumen and adapted to permit insertion of a guidewire therethrough. The catheter may still further include an angioplasty balloon located at the distal end of the catheter, the interior of the balloon in fluid communication with the second lumen. Also contemplated by the present invention is an intravascular catheter comprising a catheter shaft having a proximal end and a distal end, wherein a portion of the catheter including the distal end is normally inside a patient during use and the proximal end is normally outside the patient, a guidewire lumen extending through the shaft for receiving a steerable guidewire, wherein the guidewire lumen has and outside wall, and a proximal opening at the proximal end of the shaft for insertion of a guidewire into the lumen, and means formed in the outside wall of the guidewire lumen extending distally from the proximal opening to a point normally inside the patient during use of the catheter for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. The catheter of Claim 14, wherein the guidewire removing means is a slit. The catheter may also include a side port through the outside wall of the guidewire lumen for passage of a guidewire into the lumen through the side of the catheter shaft, the side port located distally of the proximal opening and normally inside of a patient during use of the catheter. As before, the guidewire removing means can be a slit. The slit may be continuous from the proximal opening to the side port. Alternatively, it can be discontinuous, forming a perforated line from the proximal opening to the side port. Moreover, as above, the guidewire removing means can be a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. The catheter may further include a second side port communicating with the interior of the guidewire lumen. The proximal opening may be formed in the side of the catheter at a point distal of the proximal end of the catheter, and the catheter may further comprise a guidewire adapter at the proximal end of the catheter communicating with the guidewire lumen, so that a guidewire can be inserted into the guidewire lumen at the proximal portion of the catheter either through the guidewire adapter or through the proximal opening. Another embodiment of the present invention is a guidewire connector for a catheter, comprising a connector body adapted to connect to a catheter shaft and having a channel therethrough adapted to receive a guidewire and direct the guidewire into the catheter shaft, and means for permitting a guidewire in place in the connector and the catheter shaft to be moved laterally out of the connector. The permitting means may comprise a longitudinally extending slot in the connector. Alternatively, it may comprise a longitudinally severable segment of the connector that can be removed from the connector. Preferably, the slit or guidewire removing means in the side wall of the catheter extends proximally to the guidewire connector, and preferably begins at the very proximal end of the catheter. Yet another embodiment of the invention is a catheter for use with a guidewire in an invasive medical procedure, comprising a catheter shaft having a guidewire lumen therethrough, the catheter having a proximal end and a distal end and including an outside wall of the guidewire lumen, and a longitudinally removable strip forming part of the outside wall of the guidewire lumen and extending distally from the proximal end of the catheter, the strip adapted to be removed from the catheter to permit lateral removal of the guidewire from the guidewire lumen while maintaining the longitudinal positioning of the guidewire. In this catheter, the strip may be defined by two longitudinally extending weakened areas of the outside wall. Alternatively, the strip may be made of a material different from the remainder of the catheter shaft. The catheter may also have a strip that includes a longitudinally extending reinforcing member. In accordance with still another aspect of the present invention, there is provided an angioplasty catheter comprising a catheter shaft having a proximal portion and a distal end, an angioplasty balloon attached to the shaft at the distal end, a balloon inflation lumen extending through the shaft and communicating with the interior of the balloon, a guidewire lumen extending through the shaft and through the balloon for receiving a steerable guidewire, the guidewire lumen having an outside wall, wherein the guidewire lumen has a proximal opening located at a point normally outside of the patient during use of the catheter for insertion of a guidewire into the lumen, and a side port adapted to permit passage of a guidewire into the lumen through the outside wall of the guidewire lumen, the side port located distally of the proximal opening and at a point normally inside of the patient during use, and guidewire removing means in the outside wall of the guidewire lumen extending from the proximal opening to the side port for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. In one embodiment, the side port is located adjacent to and proximally of the balloon, preferably within about 35 cm of the balloon. One embodiment of the guidewire removing means is a slit through the outside wall of the catheter shaft. This slit may be continuous from the proximal opening to the side port, or may be discontinuous, forming a perforated line from the proximal opening to the side port. In another embodiment, the guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. One variation of the invention provides a second side port communicating with the interior of the guidewire lumen. Another provides a perfusion opening communicating with the interior of the guidewire lumen, the perfusion opening located between the side port and the balloon. Still another embodiment includes a Υ" connector at the. proximal opening having an axial portion through which the balloon inflation lumen extends and a side portion through which the guidewire may be inserted into the guidewire lumen, wherein at least a portion of the connector can be removed from the catheter shaft to permit a guidewire extending through the connector and into the guidewire lumen to be removed through the guidewire removing means. The connector is advantageously adapted to be separated longitudinally and at least a portion thereof removed from the catheter shaft. In one variation, the connector comprises two longitudinally separable portions having first and second longitudinal sides on different sides of the catheter shaft, the portions being hingedly joined at the first longitudinal side and separably joined at the second longitudinal side. Another embodiment of the present invention comprises an intravascular catheter comprising a catheter shaft having a proximal end and a distal end, wherein a portion of the catheter including the distal end is normally inside a patient during use and the proximal end is normally outside the patient or outside the guiding catheter, a guidewire lumen extending through the shaft for receiving a steerable guidewire, wherein the guidewire lumen has and outside wall, and a proximal opening at the proximal end of the shaft for insertion of a guidewire into the lumen, and means formed in the outside wall of the guidewire lumen extending distally from the proximal opening to a point normally inside the patient during use of the catheter for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. The guidewire removing means may be a slit, fully formed or inchoate. The catheter preferably includes a side port through the outside wall of the guidewire lumen for passage of a guidewire into the lumen through the side of the catheter shaft, the side port located distally of the proximal opening and normally inside of a patient during use of the catheter. In one embodiment of the catheter, the guidewire removing means is a slit and the slit is continuous from the proximal opening to the side port. In another, the guidewire removing means is a slit and the slit is discontinuous, forming a perforated line from the proximal opening to the side port. In still another embodiment, the guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. According to one modification, the catheter may further comprise a second side port (such as a perfusion port) communicating with the interior of the guidewire lumen. The present invention also includes a catheter for use in an animal body with a guidewire, comprising a catheter shaft having a proximal end and a distal end with at least two lumens extending therethrough, and a "Y" connector surrounding at least a portion of the proximal end of the catheter shaft and having at least two arms, one arm providing an access channel into one of the lumens and another arm providing an access channel into another of the lumens, wherein the Υ" connector has at least two segments joined together in a separable manner along a longitudinal line so that upon separation of the segments, the "Y" connector no longer surrounds the portion of the proximal end of the catheter shaft. In one embodiment, upon separation of the segments, one of the segments is completely removable from the catheter shaft. In another embodiment, upon separation of the segments, the connector is completely removable from the catheter shaft in such a manner that an elongate object extending through one arm of the connector into a lumen of the catheter shaft can remain in the lumen during such removal of the connector. The invention further includes a method of removing a catheter during a procedure involving vascular catheterization, comprising the steps of providing a catheter of the type described above having a guidewire passing through the guidewire lumen from the proximal opening to the distal opening thereof and positioning the catheter in a patient with the proximal end of the guidewire extending out of the proximal opening, holding the proximal end of the guidewire to maintain the positioning of the guidewire in the patient while removing the catheter from the patient by moving the guidewire laterally out of the guidewire lumen through the guidewire removing means until the entire catheter is outside the patient and outside the guiding catheter and a portion of the guidewire is exposed at the distal end of the catheter, and then holding the exposed portion of the guidewire and removing the catheter off of the proximal end of the guidewire. The method may also include inserting another catheter, with the guidewire in the guidewire lumen at the distal portion of the catheter and either remaining in the guidewire lumen for the entire length of the catheter that is inside the patient during use, or extending out through the side of the catheter and running parallel to the catheter proximal of the distal portion of the catheter. Another embodiment of the invention includes a catheter for vascular use, comprising a catheter shaft with a proximal end and a distal end and having first and second lumens therethrough, the first lumen having an outside wall and being adapted to receive a guidewire extending through the first lumen, a guidewire connector attached to the proximal end of the catheter communicating with the first lumen and adapted to direct a guidewire into the first lumen, and means for permitting the guidewire to be removed laterally through the outside wall of the first lumen while maintaining the longitudinal positioning of the guidewire in the patient. The catheter may further include means for removing at least a portion of the guidewire connector from the guidewire. In one embodiment, the guidewire connector is adapted to be removed, at least in part, from the catheter shaft. In another, a portion of the guidewire connector is adapted to be removed longitudinally off of the proximal end of the catheter shaft and off of the proximal end of the guidewire. Optionally, another portion of the guidewire connector is adapted to remain on the catheter shaft while the guidewire is removed laterally out of the guidewire connector through the outside wall of the guidewire lumen. BRIEF DESCRIPTION OF THE DRAWINGS Figure 1 is a foreshortened plan view of a catheter according to the present invention. Figure 1 A is a transverse cross section of the catheter of Figure 1, taken along the line A-A. Figure IB is a transverse cross section of the catheter of Figure 1, taken along the line B-B. Figure 1C is a transverse cross section of the catheter of Figure 1 corresponding to Figure IB, but illustrating the opening of the guidewire removing means. Figure 2 is a fragmentary view of a portion of the catheter shaft of the Figure 1 catheter surrounding the proximal opening, illustrating one variation of the guidewire removing means. Figure 3 is a longitudinal cross section of the catheter of Figure 1 taken along the line 3-3, illustrating the guidewire in place and the function of the guidewire removing means. Figure 4 is a cross sectional fragmentary perspective view of the catheter of Figure 1, taken along the line B-B, illustrating another variation of the guidewire removing means. Figure 5 is a longitudinal cross section corresponding to Figure 3, illustrating movement of the guidewire laterally out of the guidewire removing means. Figure 6 is a foreshortened longitudinal cross section of the proximal end of one embodiment of the catheter of the present invention. Figure 7 is a perspective view of a removable "Y" connector at the proximal end of the catheter shaft. Figure 8 is a detailed perspective view of a locking mechanism on the "Y" connector of Figure 7. Figure 9 is a transverse cross section taken along the line 9-9 in Figure 7. Figure 10 is a detailed perspective view of another locking mechanism on the "Y" connector of Figure 7. Figure 11 is an exploded transverse cross section corresponding to Figure 9, illustrating removal of the "Y" connector from the catheter shaft. Figure 12 is a perspective view of the distal end of the catheter shaft after removal of the "Y" connector, illustrating a sealing member. Figure 13 is a longitudinal cross section of the removable "Y" connector, taken along the line 13-13 in Figure 7. Figure 14 is a longitudinal cross section of the entire catheter, taken along the line 13-13 in Figure 7. Figure 15 corresponds to Figure 14, except that the guidewire is illustrated in place in the guidewire lumen. Figure 16 is a foreshortened side elevation of another embodiment of the catheter of the present invention. Figure 17 is a longitudinal cross-section of the catheter of Figure 16, taken along the line 17-17. Figure 18 corresponds to Figure 17, except a removable breakaway portion is shown in phantom. Figure 19 corresponds to Figure 18, and illustrates lateral removal of a guidewire through a breakaway Υ connector. Figure 20 corresponds to Figure 19, further illustrating removal of the guidewire through the sidewall of the guidewire lumen. Figure 21 is an exploded view of the breakaway Υ H connector of the present invention. Figure 22 is a sectional view taken along the line 22-22 in Figure 21. Figure 23 is a sectional view taken along the line 23-23 in Figure 21. Figure 24 is a sectional view taken along the line 24-24 in Figure 21. Figure 25 is a sectional view taken along the line 25-25 in Figure 21. Figure 26 corresponds to Figure 21, except that the breakaway portion of the "Y" connector is assembled with the remainder of the "Y" connector. Figure 27 is a cross-section taken along the line 27-27 in Figure 26. Figure 28 corresponds to Figure 27, except that the breakaway portion of the H Y" connector has been removed and is illustrated in phantom. Figure 29 is a partial transverse cross-section of one embodiment of the catheter shaft illustrating a removable longitudinal strip. Figure 30 corresponds to Figure 29, illustrating a different kind of removable strip. Figure 31 corresponds to Figure 29, further illustrating yet another type of removable strip. Figure 32 is a side elevation of one embodiment of the side port. Figure 33 is a side elevation of another embodiment of the side port. DETAILED DESCRIPTION OF THE INVENTION A basic embodiment of the catheter of the present invention is illustrated in Figure 1. A catheter 10 is provided with a catheter shaft 12 extending from a proximal end 14 to a distal end 16. As shown more clearly in Figure IB, the interior of the catheter shaft 12 has a guidewire lumen 20 and a balloon inflation lumen 22 extending through the catheter shaft 12. The catheter 10 has an angioplasty balloon 24 at the distal end 16 thereof. At the proximal end 14 of the catheter shaft 12, a balloon inflation connector 26 is provided in fluid communication with the balloon lumen 22. Fluid introduced into the proximal end of the balloon inflation connector 26 can travel through the balloon lumen 22 and into the interior of the balloon 24 to inflate and deflate the balloon 24 during an angioplasty procedure. The balloon inflation lumen 22 terminates inside the balloon 24. The opposite end of the balloon inflation lumen 22 terminates inside the balloon inflation connector 26. The guidewire lumen 20 is adapted to receive a steerable guidewire and has an outside wall 30 (shown in Figure IB). A proximal opening 32 is provided through the outside wall 30 of the guidewire lumen 20. This proximal opening 32 is situated in the proximal portion of the catheter shaft 12 at a location sufficiently close to the proximal end 14 that it is normally outside of the patient during the angioplasty (or other vascular procedure). Typically , the proximal opening 32 will be within 60 cm, preferably within about 40 cm, more preferable within about 30 cm of the proximal end 14 of the catheter 10. The balloon 24 is made in accordance with conventional techniques for fabricating angioplasty balloons. Preferably, it is either blown from the distal end 16 of the catheter shaft 12, or is blown or formed of a separate piece of material which is bonded to the distal end of 16 of the catheter shaft 12. The balloon 24 may advantageously be formed of relative inelastic polymer material, such as polyethylene, polypropylene, polyvinylchloride, polyethylene terephthalate, and the like. The catheter shaft 12 is also provided with a side port 34 which extends through the outside wall 30 of the guidewire lumen 20. The side port 34 is located distally of the proximal opening 32, and is located at a point normally inside of the patient when the catheter is properly place for performance of angioplasty procedure. Preferably, the side port 34 is located proximally of the balloon 24 and within 80 cm, preferably 60 cm, and more preferably about 40 cm of the balloon 24. The catheter 10 of the present invention is provided with a means for removing a guidewire that is inside of the guidewire lumen out of the guidewire lumen 20 through the outside wall 30 of the guidewire lumen 20. If the catheter shaft 12 or the guidewire is considered to extend in a longitudinal or axial direction, this movement of the guidewire out of the guidewire lumen 20 can be considered as a sideways, radial, or transverse motion of the guidewire. The guidewire removing means 40 is adapted to form a slit through the outside wall 30 of the guidewire lumen 20 through which the guidewire may be removed from inside the guidewire lumen 20. The guidewire removing means 40 may be an actual slit cut entirely through the side wall 30 of the guidewire lumen 20. Alternatively, it may be an inchoate slit such as the weakened area illustrated in Figure IB. The guidewire removing means 40 may be cut entirely through the outside wall 30 of the guidewire lumen 20 only in certain sections, leaving other section at least partially intact, to form a sort of perforated line. It may be formed of a different material than the remainder of the catheter shaft 12 and even of a different material than the adjacent portions of the outside wall 30 of the guidewire lumen 20. Combinations of fully formed slits and weakened areas or inchoate slits are also contemplated, such as having an inchoate slit in portions of the catheter normally outside the patient during use (eliminating backbleeding through the slit) and a fully formed slit in a portion of the catheter normally inside the patient during use. One advantage of having only an inchoate slit is that it prevents backbleeding out of the guidewire removing means 40 during performance of the procedure. It is possible, however, to use an inchoate slit for only the portion of the guidewire removing means 40 that is outside of the guiding catheter in use. The remainder of the guidewire removing means 40 that is outside the patient and outside the guiding catheter can be a fully formed slit or a perforated slit without creating backbleeding problems. As illustrated in Figure 2, the guidewire removing means 40 may comprise a removable tear strip 42 defined by a pair of weakened lines 44, 46 extending distally from the proximal opening 32. The guidewire removing means 40 extends from the proximal opening 32 distally along the length of the catheter shaft 12 to a point that is ordinarily inside the patient when the catheter 10 is properly placed for performance of an angioplasty procedure. Thus, the guidewire removing means 40 begins at a point ordinarily outside the patient and outside the guiding catheter upon proper placement of the catheter 10 and extends distally to a point ordinarily inside the patient upon such placement. From another perspective, it can be said that the guidewire removing means 40 extends distally for at least 40 cm, preferably at least 60 or 70 cm, and more preferably at least 80, 90 or 100 cm. The guidewire removing means 40 may advantageously extend distally to the side port 34, and in one embodiment of the invention, may extend an additional distance distally beyond the side port 34. The guidewire removing means 40 preferably terminates proximally of the balloon 24, and may be immediately adjacent the balloon 24 or may be 5 cm, 10 cm, or more proximally of the balloon 24. If the guidewire removing means 40 is not a slit prior to its use, it becomes a slit or opening after use, an illustrated in Figure IC. The use of the catheter 10 of the present invention is illustrated in Figure 3. In this longitudinal cross sectional view, the catheter 10 is illustrated with a guidewire 50 in place in the guidewire lumen 20. The proximal portion of the guidewire 50 is outside of the catheter 10. The guidewire 50 passes through the proximal opening 32 into the guidewire lumen 20, and is inside the guidewire lumen 20 for the entire length of the catheter shaft 12 that extends distally from the proximal opening 32. The distal end of the guidewire 50 extends out of the distal end 16 of the catheter shaft 12. When the guide wire is to be removed radially or laterally out of the guidewire lumen 20, the guidewire removing means 40 provides a slit or opening in the outside wall 30 of the guidewire lumen 20 through which the guidewire 50 may be removed from the guidewire lumen 20. This slit or opening, if not fully formed, may be completed by cutting the outside wall 30 of the guidewire lumen 20, by tearing or rupturing a weakened area in the outside wall 30, or by tearing loose a removable strip (as illustrated in Figure 2). In a preferred embodiment the guidewire removing means 40 is a weakened area that is fully opened only when the guidewire 50 is removed through the guidewire removing means 40. In one embodiment, the guidewire 50 is simply pulled through the outside wall 30 of the guidewire lumen 20. Alternatively, as illustrated in Figure 4, the catheter shaft 12 may be provided with a filament 52 in association with the guidewire removing means 40. The filament 52 may be a continuous fiber or strand extending along the length of the guidewire removing means and inside at least a portion of the outside wall 30 of the guide wire lumen 20. When the filament 52 is pulled outwardly, it tears a slit into the outside wall 30 of the guidewire lumen 20. In Figure 3, the initial removal of the guidewire 50 through the guidewire removing means 40 is illustrated in phantom. In that figure, an phantom guidewire 50 is illustrated extending through the outside wall 30 of the guidewire lumen 20 at a point distally of the proximal opening 32. As illustrated in Figure 5, the phantom guidewire 50 is pulled through the outside wall 30 of the guidewire lumen 20 until the guidewire 50 has been removed through the outside wall 30 up to the side port 32. It will be understood, of course, that in accordance with the present invention, the guidewire 50 may be removed through the outside wall 30 to a point proximal of or distal of the side port 34; however, in a preferred embodiment, the lateral removal out of the guidewire lumen 20 continues up to the side port 34. It should be noted that the removal of the guidewire 50 through the outside wall 30 can be accomplished without longitudinal or axial movement of the guidewire 50. Thus, in Figure 3, the distal tip of the guidewire 50 is in the same position as in Figure 5; however, in Figure 5, the guidewire has been removed laterally through the guidewire removing means along a portion of the length of the catheter shaft 12. In th e simplest embodiment of the present invention the guidewire lumen 20 may be provided simply with a proximal opening 32, a side port 34, and guidewire removing means 40 extending distally of the proximal opening 32 at least to the side port 34, and perhaps beyond. However, more sophisticated versions of the present invention are also contemplated. In one such embodiment, a distal side opening 54 may be provide through the outside wall 30 of the guidewire lumen 20 to provide access into the guidewire lumen 20 at a point distal of the sideport 34. The distal side opening 54 may be open in normal use; however, the distal side opening 54 is preferably covered with a removable patch 56, as best seen in Figures 3 and 5. The removable patch 56 is preferably made of foil, mylar, aluminized or metalized mylar, or other suitable material, and may be held in place with an adhesive. The removable patch 56 may be removed from the catheter shaft 12 to open up the distal side opening to permit extension of the guidewire 50 through the distal side opening or to permit use of the distal side opening 54 as a perfusion opening. In one embodiment of the invention, the guidewire removing means 40 extends distally to the distal side of opening 54. The portion of the guidewire lumen 20 located proximally of the proximal opening 32 is preferably closed, and may be filled with a filler 60 such as a polymer material formed in place or a stylet inserted in a waterproof manner into a guidewire lumen 20, as illustrated in Figures 3 and 5. In an alternative embodiment of the invention, the catheter of Figure 1 is modified as its proximal end as illustrated in Figure 6. Specifically, this particular catheter has a conventional "Y" connector 62 at the proximal end 14 of the catheter shaft 12 having a balloon inflation connector 26 and a guidewire connector 64 at the two "branches" of the "Y". The guidewire lumen 20 extends from the proximal end 14 of the catheter shaft 10 through the guidewire connector 64 and the "Y" connector 62 and extends distally the length of the catheter shaft 12. The proximal opening 32 is located distally of the "Y" connecter. The catheter 10 is provided with a sliding cover 66 that is axially movable to cover or uncover the proximal opening 32. The sliding cover 66 is preferably an annular sleeve circling the catheter shaft 12 and axially movable with respect thereto. The sliding cover 66 preferably has a soft sealing material 70 (such as a pliable closed cell polymer foam, a silicone elastomer, or other suitable material) on its inside surface to provide a seal against the catheter shaft 12. Ordinarily, the sliding cover 66 is over the proximal opening 32, closing and sealing the proximal opening 32. In an alternative embodiment, the sliding cover 66 may be replaced by a removable covering (not illustrated) similar to the removable patch 56 to close the proximal opening 32 until it is used. In ordinary use, the guidewire 50 extends distally through the guidewire connector 64, the remainder of the "Y" connector 62, inside the guidewire lumen 20, past the proximal opening 32, and out of the distal end 16 of the catheter 10. When required (as will be explained in more detail hereafter), the sliding cover 66 or other seal covering the proximal opening 32 is removed, the catheter 10 is maintained in place in the patient while the guidewire 50 is removed proximally out of the guidewire connector 64, and the guidewire 50 is then inserted through the proximal opening 32 until it is in the desired position. Then the guidewire 50 is removed out through the outside wall 30 of the guidewire lumen 20 as explained in more detail elsewhere. Removal of the guidewire 50 through the outside wall of the catheter shaft 12 permits conversion of the catheter from an over-the-wire catheter to a rapid exchange catheter that can be removed from the patient without extension of the guidewire 50. In the embodiment illustrated in Figure 6, because a conventional guidewire connector 64 is ordinarily used, back bleeding during use is eliminated by tightening the Tuehy-Borst adapter (not shown) except when manipulating the guidewire 50. This is in contrast to the embodiment illustrated in Figure 1, where some back bleeding. might be expected. In yet another embodiment of the invention, the guidewire removal and reinsertion explained in connection with Figure 6 is eliminated by providing a removable "Y" connector 80, illustrated in Figures 7-13. The particular embodiment of removable "Y" connector illustrated in Figure 7 provides an axially separable "Y" connector 80. The "Y" connector 80 is preferably molded of a relatively hard thermoplastic material, and is adapted to fit concentrically around the catheter shaft. The removable "Y" connector 80 is formed of 2 (or more) pieces which are joined together along lines extending in the axial or longitudinal direction of the catheter shaft 12. In the illustrated embodiment, the removable "Y" connector has an axial portion 82 through which the balloon lumen 22 (and preferably the catheter shaft 12) extends. The removable "Y" connector 80 further has a guidewire connector 64 extending proximally and at an angle outwardly from the axial portion 82 of the removable "Y" connector 80. The guidewire connector 64 of the removable "Y" connector 80 is cylindrical in shape and has a guidewire bore 84 extending therethrough. The guidewire bore 84 connects through the proximal opening 32 into the guidewire lumen 20, as best illustrated in Figure 13. The removable "Y" connector 80 is preferably formed of a first half 86 and second half 90. The first half 86 and the second half 90 each have a semi cylindrical recess 92, 94 extending axially along the length of each half 86, 90 of the removable "Y" connector 80. The semi cylindrical recesses 92,94 are best illustrated in Figure 11. When the first and second halves 86, 90 are joined together, the semi cylindrical recesses 92, 94 together form a cylindrical recess through which the catheter shaft 12 extends. When the first and second halves 86, 90 are joined together on the catheter shaft 12, they are joined at a first edge 96 and a second edge 100 on opposite sides of the catheter shaft 12. The first and second edges 96, 100 of each half 86, 90 extend axially parallel to the axis of the catheter shaft 12. In a preferred embodiment of the invention, the first edges 96 of the first and second halves 86, 90 are joined by a hinge 102. Preferably, the hinge 102 is a "live" hinge ; that is, a hinge formed of a thin portion of the polymer material of which the removable Υ" connector 80 is formed. In a preferred embodiment, the hinge 102 extends axially the entire length of the first edge 96. The second edges 100 of the first and second halves 86, 90 are separably joined together by any appropriate connecting mechanism. The illustrated mechanism is but one possibility. In the illustrated mechanism, the second edge 100 of the first and second halves 86, 90, comprises on each half a radially extending tab 104 running the length of the second edge 100. At the outside radial edge of the tabs 104 is a flange 106 formed so that when the first and second halves 86, 90 are mated together at their second edges 100, the flanges 106 extend in opposite directions on the first and second halves 86, 90, forming a "T" shape in radial cross section as shown in Figure 9. An edge connector 110 is provided to hold the second edges 100 of the first and second halves 86, 90 together. The edge connector 110 preferably extends the entire length of the second edges 100 and is formed with a T" channel inside to lock together the tabs 104 and flanges 106 of the second edges 100 of the first an second halves 86, 90. Thus, the T" of the mated second edges of the first second edges 100 of the first and second halves 86, 90 is adapted to slide inside the T" channel of the edge connector 110. Once the connector 110 is place on the T of the second edges, it may be locked in place using any appropriate mechanism. In one embodiment, a first end 112 of the connector is permanently closed to prevent movement of the edge connector 110 in one direction. The second end 114 of the edge connector 110 may have a breakaway end 116, as illustrated in Figures 7 and 8. The breakaway end 116 is glued or otherwise connected to the remainder of the connector 110 in such a manner that it may be readily severed from the edge connector 110. This may be done by a rocking motion applied to the breakaway end 116 as illustrated in by the arrows 120 in Figure 7. Once the breakaway end 116 is removed as illustrated in Figure 8, the connector 110 may be moved axially in the direction indicated by arrow 122 until the edge connector 110 is removed from the remainder of the removable "Y" connector 80. Another method for locking the edge connector 110 onto the removable "Y" connector 80 is by use of a locking pin 124 as illustrated in Figure 10. The locking pin may extend through the edge connector 110 and the second edges 100 of the first and second halves 86, 90, to lock the edge connector 100 in place. When the pin 124 is removed, the edge connector 110 may also be removed. Although the pin 124 illustrated in Figure 10 is circular, any other suitable pin or locking device may similarly be used. After the removal of the edge connector 110, the first and second halves 86, 90 may be removed from the catheter shaft 12 as illustrated in Figure 11 by pivoting the second edges 100 away from each other. The removable "Y" connector 80 may then be slid proximally off the proximal end of the guidewire 50. In a preferred embodiment of the invention, a seal 126 is provided around the catheter shaft 12 as illustrated in Figure 12. The seal 126 prevents leakage between the removable "Y" connector 80 and the catheter shaft 12, and is preferably formed of annular polymer material such as elastomeric material or closed cell foam. The seal 126 is preferably provided with an index feature 130 for preventing rotational or longitudinal movement of the in-place "Y" connector 80 with respect to the catheter shaft 12. In the illustrated embodiment, the index feature 130 is an outwardly extending tab; however, the index feature 130 could alternatively be a groove, a recess, a flange, or the like. The outwardly-extending index feature 130 illustrated in Figures 12 and 11 can cooperate with a complimentary index receptacle 132 on the axial portion 82 of the removable "Y" connector 80. The use of the removable "Y" connector is further illustrated in Figures 14 and 15. The catheter 10 without the "Y" connector 80 in place is illustrated in Figure 14. A guidewire 50 is inserted into the proximal opening 32 through the guidewire adapter 64, as seen in Figure 15. The guidewire 50 extends the length of the catheter shaft 12 and out of the distal end 16 of the catheter 10. When the removable "Y" connector 80 is removed from the catheter shaft 12, the catheter 10 is properly illustrated in Figure 3, and the guidewire 50 can be removed laterally through the outside wall 30 of the guidewire lumen 20 as illustrated in Figures 3 and 5, and as previously explained. Although the removable "Y" connector 80 has been discussed in the context of a particular preferred embodiment, will be understood that equivalent removable "Y" connectors can be provided in which only a portion (such as a strip) of the "Y" connector is removed from the catheter shaft 12; or where there are more than 2 separably pieces of the "Y" connector; where alternative latches or locking mechanisms are utilized to hold the removable "Y" connector together until removal is desired. Further, other mechanical features having equivalent function can be substituted for other of the various described elements. A catheter according to the invention having another version of the "Y" connector is illustrated in Figures 16 and 17. This embodiment of the invention is referred to as the "universal mode" vascular catheter. In this embodiment of the invention, a catheter 210 is provided with a catheter shaft 212 having a proximal end 214 and a distal end 216. The catheter shaft 212 is provided with a guidewire lumen 220 and a balloon lumen 222 extending the length of the catheter shaft 212. A conventional angioplasty balloon 224 is provided at the distal end 216 of the catheter shaft 212. The balloon 224 is inflated by introducing pressurized fluid through the balloon inflation connector 226 located at the proximal end 214 of the catheter shaft 212. Such pressurized fluid travels distally from the balloon inflation connector 226 through the balloon inflation lumen 222 which communicates with the interior of the balloon 224. The guidewire lumen 220 has an outside wall 230, and a proximal opening 232. The catheter 210 is also provided with a side port 234 providing an opening through the outside wall 230 of the guidewire lumen 220. The side port 234 corresponds to the side port 34 previously described, and is adapted to permit insertion or removal of a guidewire therethrough. Preferably, the side port 234 is configured such that a guidewire passing through the side port 234 may easily extend distally through the guidewire lumen 220, but is adapted to discourage a guidewire passing through the side port 234 from extending proximally through the guidewire lumen 220 from the side port 234. The location of the side port 234 is as previously described in connection with the side port 34. The guidewire lumen 220 extends substantially the entire length of the catheter shaft 212 from the proximal opening 232 through the balloon 234 to a distal opening 236 located distally of the balloon 224. Located at the proximal end 214 of the catheter 210 is a guidewire connector 240 adapted to provide access to the guidewire lumen 220. The proximal opening 232 of the guidewire lumen 220 is a channel extending through the guidewire connector 240. The guidewire connector 240 may advantageously be located proximally of the balloon inflation connector 226; however, it is also contemplated that the guidewire connector 240 may be located distally of the balloon inflation connector 226. In one preferred embodiment of the invention, the guidewire connector 240 and the balloon inflation connector 226 together comprise a "Y" connector 242 as illustrated in Figure 17. In the preferred embodiment of the "Y" connector 242, the guidewire connector 240 and the balloon inflation connector 226 are connected together and are formed of an appropriate material such as a molded polymer material. The guidewire connector 240, for example, may be coaxial with the guidewire lumen 220, while the balloon inflation connector 226 may extend at an angle from the balloon inflation lumen 222. In this manner, the connectors 226, 240 together form a "Y". As illustrated in Figure 18, one preferred embodiment of the universal mode catheter 210 includes a "Y" connector 242 having a breakaway piece 246. The breakaway piece 246 is illustrated in Figure 18 in phantom. As illustrated, when the breakaway piece of the "Y" connector 242 is removed, the outside wall 230 of the guidewire lumen 220 is exposed for its entire length. The breakaway piece 246 can be completely removed from the remainder of the "Y" connector, or it may be hinged to simply pivot away from the remaining portion of the connector. The outside wall 230 of the guidewire lumen 220 in this embodiment of the invention is provided with guidewire removing means 250. The guidewire removing means 250 corresponds to the guidewire removing means 40 previously discussed. As illustrated in Figure 19, when a guidewire 252 is in place in the guidewire lumen 220, the breakaway piece 246 can be removed from the guidewire connector 240 so that the guidewire 252 can be moved laterally through the guidewire removing means 250 through the outside wall 230 of the guidewire lumen 220. (The guidewire extending through the guidewire lumen 220 from the proximal end 214 is illustrated in phantom; the solid guidewire 252 is illustrated after lateral removal from the portion of the guidewire lumen 220 out of the guidewire connector 240 and the "Y" connector 242.) Figure 20 illustrates further removal of the guidewire 252 laterally through the outside wall 230 of the guidewire lumen 220 by means of the guidewire removing means 250. In Figure 20, the guidewire 252 is illustrated in a phantom starting position corresponding to the guidewire in Figure 19, and in solid illustrating further removal laterally through the guidewire removing means 250 until the guidewire 252 is extending through the side port 234. Removal of the guidewire 252 through the guidewire removing means 250 is accomplished in the same manner as previously discussed. The breakaway connector 242 of this embodiment of the invention is illustrated in more detail in Figures 20-25. Figure 21 is a perspective view of the "Y" connector 242 from the side opposite the balloon inflation connector 226 (which is hidden in Figure 21). In Figure 21, the guidewire connector 240 is provided with a removable breakaway piece 246 on the side of the guidewire connector 240 opposite the balloon connector 226. The guidewire connector 240 is preferably formed of injection-molded thermal plastic material. In a preferred embodiment, it is formed integrally with the remainder of the "Y" connector 242. At the distal end of the "Y" connector 242 (where it meets the catheter shaft 212) a stress relief sleeve 254 may advantageously be provided. The stress relief sleeve 254 may be formed of flexible polymer material. It advantageously encircles the catheter shaft 212 from a point inside the dial end of the "Y" connector 242 extending a short distance (e.g. 1-2 cm) distally of the "Y" connector 242 to prevent buckling of the catheter shaft 212. The removable breakaway piece 246 preferably overlays a portion of the outside wall 230 of the guidewire lumen 220. In radial cross-section the breakaway piece 246 may, for example, comprise from about 5° to about 180° of arc. In the embodiment illustrated in Figure 21, the breakaway piece 246 encircles the catheter shaft 212 for about 90° to 120° of arc. Although the longitudinally extending breakaway piece 246 is shown extending the entire length of the "Y" connector 242, it should be understood that a "Y" connector having an axially removable proximal portion (outlined by dashed line "A" in Figure 27) that entirely encircles a guidewire and a longitudinally extending, radially removable portion (outlined by dashed line "B" in Figure 27) is also contemplated. To use this embodiment, the encircling proximal portion "A" is removed axially, and the longitudinally extending portion "B" is removed radially. In another variation of this embodiment, the portion "B" may simply be eliminated, leaving a slot, and the lateral or radial removal of the guidewire 252 from the "Y" connector can be accomplished after removing portion "A" (as by unscrewing it from the remainder of the "Y" connector 242 and sliding it off of the proximal end of the guidewire 252). The breakaway piece 246 may advantageously be formed from the same material as the remainder of the "Y" connector 242. It may be molded separately from the remainder of the "Y" connector 242; alternatively, the "Y" connector may be molded in one piece, and then the breakaway piece 246 may be cut form the "Y" connector 242. The catheter may even be provided with the breakaway piece 246 entirely missing. In this embodiment, a narrow longitudinal slot is provided along the side of the "Y" connector at all times. The proximal end of the guidewire connector 240 may then be removable and may completely encircle the guidewire. In any event, means (not illustrated) for holding the breakaway piece 246 in place until removal is desired should be provided. These means may include a relatively weak adhesive or weld joining the edges of the breakaway piece 246 to the corresponding edges of the remainder of the "Y" connector 242. Alternately, the breakaway piece 246 may be incompletely cut from the remainder of the "Y" connector 242. In another embodiment, the breakaway piece 246 may be held in place by tape encircling the breakaway piece 246 and all or part of the guidewire connector 240 and/or the "Y" connector 242. The guidewire connector 240 preferably has a circular flange encircling the proximal end thereof to facilitate connection of adapters and the like. When the breakaway piece 246 is removed from the guidewire connector 240 and/or the "Y" connector 242, the guidewire removing means 250 will be exposed. As previously discussed, the guidewire removing means may be a slit, a weakened line, a tear-away strip, or other equivalent means for removing the guidewire 252 laterally through the outside wall 230 of the guidewire lumen 220. In addition to removing the breakaway piece 246, at least a portion of the stress relief sleeve 254 must also be removed, as also illustrated in Figure 21. The stress relief sleeve 254 may be slit or cut and the removable portion may be connected to the breakaway piece 246. Alternatively, the stress relief sleeve 254 may simply be slit and not removed from the outside wall 230 of the guidewire lumen 220. The construction of the breakaway "Y" connector is further illustrated in cross- section in Figure 22-24. In Figure 22, the proximal end of the guidewire connector 240 is illustrated, showing the unitary polymer construction thereof. In Figure 23, the unitary guidewire connector 240 is shown encircling only the guidewire lumen 220 of the catheter shaft 212. In Figure 24, the balloon inflation connector 226 is shown extending from the far side of the "Y" connector 242. The guidewire connector portion of the "Y" connector 242 is shown encircling both the guidewire lumen 220 and the balloon inflation lumen 222. The stress relief sleeve 254 is shown between the guidewire connector 240 and the catheter shaft 212. Finally, in Figure 25, the catheter shaft distal of the "Y" connector 242 is illustrated, showing the guidewire wire 220, the balloon inflation lumen 222, and the outside wall 230 of the catheter shaft 212. Figure 26 is an illustration of the "Y" connector 242 assembled together with the breakaway piece 246. The stress relied sleeve 254 is illustrated partially cut away. This partial cut-away of the portion of the stress relief sleeve 254 may represent the actual finished product. In other words, the finished product may have the portion of the stress relief sleeve 254 overlying the guidewire removing means 250 removed. Alternatively, that portion of the stress relief sleeve 254 may be removable when the breakaway piece 246 is removed. Figure 27 is a longitudinal cross-section of the "Y" connector 242. It illustrates the placement of the stress relief sleeve 254 partially inside the "Y" connector 242. Connector flanges 256 are provided on both the guidewire connector 240 and the balloon inflation connector 226. In order to facilitate insertion of the guidewire 252 and connection to appropriate connectors and adapters, the proximal opening 232 of the guidewire lumen is preferably flared so that the channel extending through the guidewire connector is wider at its proximal end 214. Figure 28 corresponds to Figure 27, except that the breakaway piece 246 has been removed and is illustrated in phantom. Figure 29 illustrates yet another embodiment of the guidewire removing means 250. In this illustrated embodiment, the outside wall 230 of the guidewire lumen 220 is provided with two weakened areas 260, 262 extending parallel and longitudinally along the outside wall 230 of the guidewire lumen 220. In a preferred embodiment, the weakened areas 260, 262 each comprise a juxtaposed pair of continuous or interrupted grooves formed in the outside wall 230, one inside the wall and the other outside the wall 230. An optional reinforcing filament 264 is provided in the segment of the outside wall 230 located between the weakened areas 260, 262. The reinforcing filament 264 may advantageously comprise a high tensile strength thread or filament, such as nylon or polyaramid (e.g., the material sold by du Pont under the trademark KEVLAR). Alternatively, it may be formed of metal. The portion of the outside wall 230 bounded by the weakened areas 260, 262 comprises a tear-away strip 266. This strip 266 may be the same thickness as the remainder of the catheter shaft wall; it may be thinner; or it may be thicker. In use, the tear-away strip may be removed by grasping it at the proximal end and tearing distally. Alternatively, it may be removed simply by pulling the guidewire laterally through the outside wall 230 of the guidewire lumen, pulling the tear-away strip 266 in the process. Another version of the tear-away strip 266 is illustrated in Figure 30. In this embodiment, the tear-away strip 266 is formed of a different material than the remainder of the outside wall 230 of the guidewire lumen 220. This particular tear-away strip 266 may be formed, for example, by co-extruding a second material with the catheter shaft 212. The portions of the outside wall 230 adjacent to the guidewire removing means 250 are separated by the width of the tear-away strip 266, and the tear-away strip 266 overlaps the outside wall 230 on both the inside and outside of the outside wall 230. This overlapping, interlocking feature anchors the tear-away strip 266 to the outside wall 230 until removal is desired. Still another embodiment of the tear-away strip 266 is illustrated in Figure 31. In this embodiment, the tear-away strip 266 (which is advantageously formed of a separate or different material from the outside wall 230) is adhesively attached to the outside wall 230. It may be removed in a manner similar to that discussed in connection with Figures 28 and 29. Whether the catheters of the present invention include a tear-away strip or a slit (formed or inchoate) as the guidewire removing means, it should be understood that the side port is optional when the catheter is used as an over the wire catheter. The side port is useful, however, when one inserts the catheter in rapid exchange mode, with the guidewire passing through the outside wall of the guidewire lumen into the guidewire lumen at a point on the catheter that is ordinarily inside the patient during use of the catheter. There are many alternative geometries that can be used for the side ports 34, 234, which are applicable to all of the catheters described herein. For example, with reference to Figure 32, the side port 234 may not comprise an actual opening, but rather a slit. One configuration of a slit that is adapted for easy insertion and removal of a guidewire is a "Y" shape, where the stem of the "Y" is a guidewire removing means slit or strip 250 and the two arms of the "Y" extend at divergent angles from the stem. As shown in Figure 23, the slits may be fully formed; alternatively, they can be interrupted slits or weakened areas. It will be appreciated that there is no opening or hole in the outside wall of the guidewire lumen; rather, the edges of the slits are closed until a guidewire is passed through this version of the "side port" 34, 234. Another embodiment of the side port 34, 234 is illustrated in Figure 33. Here, the side port 234 is initially closed, and is part of the outside wall 230 of the guidewire lumen 220. Until then, the side port 234 is inchoate. When one desires to use the side port 234, the material closing the side port 234 is removed to open that side port. Thus, the side port 234 may be defined by a perforated line (interrupted slit), a weakened area, or the like. It can be connected to a single slit guidewire removing means 250, or to any of the other guidewire removing means disclosed herein. Where the guidewire removing means is a tear- away strip, the side port 234 can be connected to and a part of that strip, and may either be the same size as or an enlarged portion of that strip. METHODS OF USING THE CATHETER The catheter of the present invention may be used as a rapid exchange catheter with the guidewire 50, 252 extending through the side port 34, 234 and out of the distal end 16, 216 of the guidewire lumen 20, 220. Alternatively, it may be used as a conventional over the wire catheter with the guidewire 50, 252 extending substantially the entire length of the catheter shaft 12, 212 from the proximal end (either through a "Y" connector 62, 80, or 242 or through the proximal opening 32, 232) distally through the entire length of the catheter shaft and out of the distal end thereof. A revolutionary aspect of the catheter of the present invention is that it may readily and rapidly be converted from one mode of use to the other. Thus, it- can be used first as a rapid exchange catheter, with the guidewire extending in the guidewire lumen 20, 220 only from the side port 34, 234 to the distal end of the catheter. It can be converted from this rapid exchange mode of use to conventional over-the-wire use simply by removing the guidewire and, while maintaining the catheter 10, 210 in place in the patient, inserting a new guidewire 50, 252 into the proximal end of the guidewire lumen 20, 220 (through a "Y" connector or through the proximal opening 32, 232) and extending the guidewire 50, 252 out of the distal end of the catheter. When the catheter of Figure 4 is being used as a conventional over the wire catheter, it can be converted into a rapid exchange catheter by removing the removable "Y" connector 80 (if used), and, with the guidewire extending proximally out of the proximal opening 32, maintaining the guidewire 50 in position in the patient while moving the guidewire laterally out of the outside wall 30 of the guidewire lumen 20 through the guidewire removing means 40 and simultaneously withdrawing the catheter 10 proximally until the distal end 16 of the catheter 10 is outside of the patient. During this portion of the procedure, the guidewire 50 is held by grasping it at the proximal end. Then the operator may hold the guidewire 50 by grasping the portion of the guidewire 50 exposed at the distal end 16 of the catheter 10, remove the catheter 10 off of the proximal end of the guidewire 50, and insert a new catheter 10 over the guidewire 50 while maintaining the position of the guidewire 50 in the patient. The insertion of the new catheter 10 may be accomplished in rapid exchange mode by retrograde insertion of the proximal end of the guidewire 50 through the distal end of the catheter and out of the sideport 34. The proximal end of the guidewire is then held while the catheter 10 is advanced back into position in the patient. The catheter can then be used as a rapid exchange catheter. Alternatively, if desired, the guidewire 50 may be removed with the catheter maintained in position, and in a matter of seconds the guidewire may be reinserted through the proximal opening 32 or through the proximal end 14 of the catheter shaft 12 to convert the mode of use to conventional over the wire use. Thus, it will be appreciated that the catheter of the present invention can easily be used in either a rapid exchange mode or an over the wire mode; that conversion between modes of use may be readily accomplished; that guidewire exchange may be accomplished in either mode of use, and that catheter exchange when in either mode of use can be accomplished without use of an extension guidewire; and that all of the forgoing conversions and modes of use can be accomplished while maintaining the positioning of either the guidewire or the catheter in the patient. Thus, one method of the present invention comprises inserting the catheter of Figure 1 into the patient with the guidewire 50 going through the proximal opening 32 and extending from that point distally through the entire remaining length of the catheter shaft 12 and out of the distal end 16. The guidewire 50 can then be exchanged by removing it and reinserting it through the proximal opening 32. The catheter can be exchanged by holding the guidewire as explained above while peeling away the catheter laterally while withdrawing it so that the guidewire is pulled through the guidewire removing means 40 until the distal end of the catheter is outside the patient. The guidewire is then held distally of the catheter and a new catheter is inserted, this time in rapid exchange mode. Once that catheter is in place, the guidewire can be rapidly exchanged (if desired) to convert the catheter back into the over-the-wire mode of use as explained above. In another method of use, the catheter of Figure 6 can be used. This catheter can be used with the guidewire in the side port or the proximal opening, as explained above, with the same catheter and guidewire exchanges possible. Moreover, it can be used with the guidewire extending through the entire length of the guidewire lumen 20 through the guidewire adapter 64. Exchange of the guidewire from the guidewire adapter 64 to the proximal opening 32 and vice versa is also contemplated. The identical modes of use explained in connection with the Figure 1 catheter can be used with the removable or severable "Y" connector catheter of Figures 7-28, except the guidewire passes simultaneously through the proximal opening 32, 232 and the guidewire adapter 64, 240 of the "Y" connector 80, 242. Further, in these modes of use, the conversion from over-the-wire use to rapid exchange use will require removal of the removable "Y" connector 80 or removal a portion of the breakaway "Y" connector 242 (or other provision of a longitudinal slot or passageway through the "Y" connector) prior to and in addition to use of the guidewire removing means 40, 250. Thus, for example, the catheter 210 of Figures 16-28 can be first inserted in over the wire mode, with the guidewire 252 extending from the proximal opening 232 through the guidewire connector 240 and distally through the guidewire lumen 220, through the balloon 224, and out of the distal end 216 of the catheter. In this configuration, the catheter is inserted into the patient and positioned in the conventional manner. The guidewire 252 is exchanged simply by maintaining the positioning of the catheter 210 in the patient, withdrawing the guidewire out of the proximal end 214 of the guidewire connector 240, and inserting another guidewire 252. If exchange of the catheter 210 is necessary, the breakaway piece 246 of the "Y" connector 242 is removed, the guidewire is removed laterally out of the "Y" connector 242 beginning at the proximal end of the connector 242, and then the guidewire 252 is held securely in position while the catheter is withdrawn from the patient, simultaneously pulling the guidewire 252 laterally out of the guidewire lumen 220 through the guidewire removing means 250. Where a tear-away strip 266 comprises the guidewire removing means 250, the strip 266 is pulled off while the catheter 210 is pulled out of the patient. When the distal end 216 of the catheter 210 is out of the patient and the guidewire 252 is exposed at the distal end 216, then the guidewire is grasped distally of the catheter 210 and the catheter 210 is removed off of the proximal end of the guidewire 252. Next, a new catheter 210 is threaded onto the guidewire by inserting the guidewire into the distal end of the guidewire lumen 220, proximally through the guidewire lumen 220 to the side port 234, and out of the side port 234. The catheter 210 is then advanced into the patient over the guidewire 252 whϋe holding the guidewire 252 securely in position. If desired, the guidewire 252 can then be removed while holding the catheter 210 in position, and reinserted through the proximal end 214 of the guidewire lumen 220 through the entire length of the catheter 210, to convert back to over the wire mode. Although the present invention has been described in the context of certain preferred embodiments, it is intended that the scope of the present patent be measured with reference with the appended claims and reasonable equivalence thereof.

Claims: WHAT IS CLAIMED IS: 1. A multi-lumen vascular catheter for use with a guidewire, comprising: » a longitudinally extending catheter shaft having a proximal end and a distal end and having at least first and second lumens extending distally from said proximal end, each of said lumens having a proximal opening, wherein said first lumen is adapted to receive a guidewire; and a first connector at the proximal end of said catheter providing a first channel communicating with the interior of said first lumen for insertion of a guidewire therethrough, said connector including means for permitting a guidewire extending longitudinally through said first channel into said first lumen to be moved laterally out of said first channel through at least a portion of said first connector beginning at the proximal end of the first connector. 2. The catheter of Claim 1, wherein said first connector is adapted to separate into first and second parts to permit said lateral movement of said guidewire out of said first channel through said first connector. 3. The catheter of Claim 1, further comprising a second connector at the proximal end of said catheter providing a second channel communicating with the interior of the second lumen. 4. The catheter of Claim 3, wherein said second connector is located distally of said first connector. 5. The catheter of Claim 4, wherein said first and second connectors are joined together in the form of a "Y". 6. The catheter of Claim 1, wherein said catheter further includes guidewire removing means in the outside wall of the first lumen extending distally from the proximal opening for permitting a guidewire in the first lumen to be moved laterally from the first lumen though the outside wall of the guidewire lumen. 7. The catheter of Claim 6, wherein said guidewire removing means is a slit. 8. The catheter of Claim 7, wherein said slit is continuous from the proximal opening to a point normally inside the patient during use. 9. The catheter of Claim 7, wherein said slit is discontinuous, forming a perforated line from the proximal opening to a point normally inside the patient during use. 10. The catheter of Claim 6, wherein said guidewire removing means is a weakened area of the wall of the first lumen adapted to be severed for removal of the guidewire therethrough. 11. The catheter of Claim 10, wherein said weakened area comprises a pair of juxtaposed grooves, one on the inside and the other on the outside of the wall of the first lumen. 12. The catheter of Claim 6, wherein said guidewire removing means is a portion of the outside wall of the first lumen adapted to be removed from the catheter shaft in the form of a strip. 13. The catheter of Claim 6, further comprising a side port located at a point normally inside the patient during use, said side port extending through the outside wall of the first lumen and adapted to permit insertion of a guidewire therethrough. 14. The catheter of Claim 13, wherein said side port is adapted to permit a guidewire to pass through said side port and through the portion of the first lumen distal to said side port, but is adapted to prevent a guidewire in the portion of the first lumen proximal to the side port from passing through the side port. 15. The catheter of Claim 6, further comprising an angioplasty balloon located at the distal end of the catheter, the interior of said balloon in fluid communication with said second lumen. 16. An intravascular catheter comprising: a catheter shaft having a proximal end and a distal end, wherein a portion of said catheter including said distal end is normally inside a patient during use and said proximal end is normally outside said patient; a guidewire lumen extending through said shaft for receiving a steerable guidewire, wherein said guidewire lumen has an outside wall, and a proximal opening at the proximal end of said shaft for insertion of a guidewire into said lumen; and means formed in the outside wall of the guidewire lumen extending distally from the proximal opening to a point normally inside the patient during use of the catheter for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. 17. The catheter of Claim 16, wherein said guidewire removing means is a slit. 18. The catheter of Claim 16, further comprising a side port through the outside wall of the guidewire lumen for passage of a guidewire into said lumen through the side of said catheter shaft, said side port located distally of said proximal opening and normally inside of a patient during use of said catheter. 19. The catheter of Claim 18, wherein said guidewire removing means is a slit and said slit is continuous from the proximal opening to the side port. 20. The catheter of Claim 18, wherein said guidewire removing means is a slit and said slit is discontinuous, forming a perforated line from the proximal opening to the side port. 21. The catheter of Claim 16, wherein said guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. 22. The catheter of Claim 18, further comprising a second side port communicating with the interior of the guidewire lumen. 23. The catheter of Claim 16, wherein the proximal opening is formed in the side of the catheter at a point distal of the proximal end of the catheter, further comprising a guidewire adapter at the proximal end of the catheter communicating with the guidewire lumen, so that a guidewire can be inserted into the guidewire lumen at the proximal portion of the catheter either through the guidewire adapter or through the proximal opening. 24. A guidewire connector for a catheter, comprising: a connector body adapted to connect to a catheter shaft and having a channel therethrough adapted to receive a guidewire and direct the guidewire into said catheter shaft; and means for permitting a guidewire in place in said connector and said catheter shaft to be moved laterally out of said connector. 25. The connector of Claim 24, wherein said permitting means comprises a longitudinally extending slot in said connector. 26. The connector of Claim 24, wherein said permitting means comprises a longitudinally movable segment of said connector. 27. A catheter for use with a guidewire in an invasive medical procedure, comprising a catheter shaft having a guidewire lumen therethrough, said catheter having a proximal end and a distal end and including an outside wall of said guidewire lumen; and a longitudinally removable strip forming part of the outside wall of said guidewire lumen and extending distally from the proximal end of said catheter, said strip adapted to be removed from said catheter to permit lateral removal of said guidewire from said guidewire lumen while maintaining the longitudinal positioning of said guidewire. 28. The catheter of Claim 27, wherein said strip is defined by two longitudinally extending weakened areas of said outside wall. 29. The catheter of Claim 28, wherein said weakened areas each comprise juxtaposed grooves formed on the inside and the outside of said outside wall. 30. The catheter of Claim 27, wherein said strip is made of a material different from the remainder of said catheter shaft. 31. The catheter of Claim 27, wherein said strip further comprises a longitudinally extending reinforcing member. 32. The catheter of Claim 31, wherein said reinforcing member is on the inside of said strip. 33. A catheter for vascular use, comprising: a catheter shaft with a proximal end and a distal end and having first and second lumens therethrough, said first lumen having an outside wall and being adapted to receive a guidewire extending through said first lumen; a guidewire connector attached to the proximal end of said catheter communicating with said first lumen and adapted to direct a guidewire into said first lumen; and means for permitting said guidewire to be removed laterally through the outside wall of said first lumen while maintaining the longitudinal positioning of said guidewire in the patient. 34. The catheter of Claim 33, wherein said guidewire connector is adapted to be removed, at least in part, from said catheter shaft. 35. The catheter of Claim 33, wherein at least a portion of said guidewire connector is adapted to be laterally removed away from the first lumen. 36. The catheter of Claim 35, wherein at least a portion of said guidewire connector is adapted to be removed longitudinally off of the proximal end of the catheter shaft and off of the proximal end of the guidewire. 37. The catheter of Claim 36, wherein another portion of said guidewire connector is adapted to remain on the catheter shaft while the guidewire is removed laterally out of the guidewire connector through the outside wall of the guidewire lumen. 38. An angioplasty catheter comprising: a catheter shaft having a proximal portion and a distal end; an angioplasty balloon attached to said shaft at said distal end; a balloon inflation lumen extending through said shaft and communicating with the interior of said balloon; a guidewire lumen extending through said shaft and through said balloon for receiving a steerable guidewire, said guidewire lumen having an outside wall, wherein said guidewire lumen has a proximal opening located at a point normally outside of the patient during use of the catheter for insertion of a guidewire into said lumen, and a side port adapted to permit passage of a guidewire into said lumen through the outside wall of said guidewire lumen, said side port located distally of said proximal opening and at a point normally inside of the patient during use; and guidewire removing means in the outside wall of the guidewire lumen extending from the proximal opening to the side port for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. 39. The catheter of Claim 38, wherein said side port is located adjacent to and proximally of said balloon. 40. The catheter of Claim 38, wherein said side port is located proximally of said balloon within about 35 cm of said balloon. 41. The catheter of Claim 38, wherein said guidewire removing means is a slit. 42. The catheter of Claim 41, wherein said slit is continuous from the proximal opening to the side port. 43. The catheter of Claim 41, wherein said slit is discontinuous, forming a perforated line from the proximal opening to the side port. 44. The catheter of Claim 38, wherein said guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. 45. The catheter of Claim 38, further comprising a second side port communicating with the interior of the guidewire lumen. 46. The catheter of Claim 38, further comprising a perfusion opening communicating with the interior of the guidewire lumen, said perfusion opening located between said side port and said balloon. 47. The catheter of Claim 38, further comprising a "Y" connector at the proximal opening having an axial portion through which the balloon inflation lumen extends and a side portion through which the guidewire may be inserted into the guidewire lumen, wherein at least a portion of the connector can be removed from the catheter shaft to permit a guidewire extending through the connector and into the guidewire lumen to be removed through the guidewire removing means. 48. The catheter of Claim 47, wherein said connector is adapted to be separated longitudinally and at least a portion thereof removed from said catheter shaft. 49. The catheter of Claim 47, wherein said connector comprises two longitudinally separable portions having first and second longitudinal sides on different sides of the catheter shaft, said portions being hingedly joined at said first longitudinal side and separably joined at said second longitudinal side. 50. An intravascular catheter comprising: a catheter shaft having a proximal end and a distal end, wherein a portion of said catheter including said distal end is normally inside a patient during use and said proximal end is normally outside said patient; a guidewire lumen extending through said shaft for receiving a steerable guidewire, wherein said guidewire lumen has and outside wall, and a proximal opening at the proximal end of said shaft for insertion of a guidewire into said lumen; and means formed in the outside wall of the guidewire lumen extending distally from the proximal opening to a point normally inside the patient during use of the catheter for permitting a guidewire in the guidewire lumen to be moved laterally from the guidewire lumen though the outside wall of the guidewire lumen. 51. The catheter of Claim 50, wherein said guidewire removing means is a slit. 52. The catheter of Claim 50, further comprising a side port through the outside wall of the guidewire lumen for passage of a guidewire into said lumen through the side of said catheter shaft, said side port located distally of said proximal opening and normally inside of a patient during use of said catheter. 53. The catheter of Claim 52, wherein said guidewire removing means is a slit and said slit is continuous from the proximal opening to the side port. 54. The catheter of Claim 52, wherein said guidewire removing means is a slit and said slit is discontinuous, forming a perforated line from the proximal opening to the side port. 55. The catheter of Claim 50, wherein said guidewire removing means is a weakened area of the wall of the guidewire lumen adapted to be severed for removal of the guidewire therethrough. 56. The catheter of Claim 52, further comprising a second side port communicating with the interior of the guidewire lumen. 57. The catheter of Claim 50, wherein the proximal opening is formed in the side of the catheter at a point distal of the proximal end of the catheter, further comprising a guidewire adapter at the proximal end of the catheter communicating with the guidewire lumen, so that a guidewire can be inserted into the guidewire lumen at the proximal portion of the catheter either through the guidewire adapter or through the proximal opening. 58. A catheter for use in an animal body with a guidewire, comprising: a catheter shaft having a proximal end and a distal end with at least two lumens extending therethrough; and a "Y" connector surrounding at least a portion of the proximal end of the catheter shaft and having at least two arms, one arm providing an access channel into one of said lumens and another arm providing an access channel into another of said lumens, wherein said "Y" connector has at least two segments joined together in a separable manner along a longitudinal line so that upon separation of the segments, said "Y" connector no longer surrounds said portion of said proximal end of said catheter shaft. 59. The catheter of Claim 58, wherein upon separation of said segments, one of said segments is completely removable from said catheter shaft. 60. The catheter of Claim 58, wherein upon separation of said segments, said connector is completely removable from said catheter shaft in such a manner that an elongate object extending through one arm of said connector into a lumen of said catheter shaft can remain in said lumen during such removal of said connector. 61. A method of removing a catheter during a procedure involving vascular catheterization, comprising the steps of: providing a catheter according to Claim 1 or 13 having a guidewire passing through said guidewire lumen from the proximal opening to the distal opening thereof and positioning said catheter in a patient with the proximal end of the guidewire extending out of the proximal opening; holding the proximal end of the guidewire to maintain the positioning of the guidewire in the patient while removing said catheter from said patient by moving the guidewire laterally out of the guidewire lumen through the guidewire removing means until the entire catheter is outside the patient and a portion of the guidewire is exposed at the distal end of the catheter; and then holding said exposed portion of the guidewire and removing the catheter off of the proximal end of the guidewire. 62. A method of removing a catheter during a procedure involving vascular catheterization, comprising the steps of: providing a catheter according to Claim 57 having a guidewire passing through said guidewire lumen from one of the proximal opening and the guidewire adapter to the distal opening thereof and positioning said catheter in a patient; and removing the guidewire while maintaining the positioning of the catheter and inserting said guidewire back into the guidewire lumen and out of the distal end of the catheter through the other of the proximal opening and the guidewire adapter. 63. An angioplasty catheter, comprising: a catheter shaft having a proximal portion and a distal end; an angioplasty balloon on the distal end of said shaft; a balloon inflation lumen extending along said shaft and communicating with the interior of said balloon; a guidewire lumen extending through said shaft and through said balloon for receiving a steerable guidewire, said guidewire lumen having an outside wall, wherein said guidewire lumen has a proximal side port extending through said outside wall at a fixed point normally outside a patient during use of said catheter, and a distal port at a fixed point normally inside a patient during use of said catheter, said proximal and distal side ports each adapted to permit passage of a guidewire into said guidewire lumen through the outside wall thereof. 64. The catheter of Claim 63, further comprising: a guidewire removing means in the outside wall of the guidewire lumen extending from said proximal side port to said distal side port for permitting a guidewire in the guidewire lumen between said side ports to be moved laterally from the guidewire lumen through the outside wall of the guidewire lumen.

Inventors: JANG G DAVID, JANG, G., DAVID
Applicants: JANG G DAVID, JANG, G., DAVID
Application year: 1992
Main classification: A61M5
IPC codes: A61M25, A61M29