Rapid exchange catheter

#The present invention is in the field of catheters which are inserted into body passageways of patients for various diagnostic and therapeutic treatment. Specifically, this invention pertains to a diagnostic or therapeutic catheter which can be inserted over a guidewire, followed by removal and replacement of the diagnostic or therapeutic catheter, over the same guidewire. Such catheters are commonly referred to as over-the-wire and rapid-exchange catheters.

#Over-the-wire and rapid-exchange catheters are adaptable for various applications involving various body passageways or cavities, one of which is an intravascular procedure called percutaneous transluminal coronary angioplasty (PTCA) for dilatation of a coronary stenosis. During the performance of the PTCA procedure, it is often necessary to remove the operative catheter, whether diagnostic or therapeutic in nature, and replace it with another operative catheter.

#In the performance of a typical PTCA procedure, a guiding catheter is percutaneously introduced into the cardiovascular system of the patient. This guiding catheter typically has a distal tip which is shaped to enhance its ability to be advanced to the vicinity of the selected treatment area. The guiding catheter can be twisted or rotated to orient the shaped distal tip to follow the vascular passageways as desired. The distal tip of the guiding catheter is advanced through the cardiovascular system to the aorta, near the ostium, or mouth, of the coronary artery to be inspected or treated. At this point, the shaped distal tip of the guiding catheter is oriented into the coronary ostium.

#FIG. 1 is a schematic view of the operative catheter of the present invention in use;

#FIG. 2 is a longitudinal sectional view of the operative catheter shown in FIG. 1;

#FIG. 3 is a transverse sectional view of the operative catheter shown in FIG. 2, taken at line 3-3;

#As seen in FIG. 1, when in use, the operative catheter 10 is inserted through guiding catheter 12, which has been inserted, through the arteries, to the heart 14 of a patient. Heart 14 has a coronary artery 16 which is partially or completely occluded by stenosis 18. Distal end 20 of guiding catheter 12 has been positioned at the ostium of coronary artery 16, and guidewire 30 has been advanced toward stenosis 18. Distal end 32 of guidewire 30 is shown as having passed through stenosis 18 prior to advancement of operative catheter 10 out of guiding catheter 12, but in many situations, operative catheter 10 would be sequentially advanced in a step-wise fashion along with guidewire 30. It is also possible to use the catheter of the present invention without a guiding catheter.

#Proximal end 21 of guiding catheter 12 is joined to an adaptor 25 which contains releasable seal 24. Releasable seal 24 typically contains an O-ring which can be tightened to seal its internal opening around operative catheter 10 by tightening a nut. Contrast dye injection port 22 projects at an angle from adaptor 25. Adaptor 25 functions essentially as the proximal terminal of guiding catheter 12, and the proximal end of adaptor 25 will be considered, for the purposes of this discussion, to be the proximal end of guiding catheter 12. Guiding catheter 12, adaptor 25, and releasable seal 24 are items well known in the art. In FIG. 1, operative catheter 10 has been inserted into guiding catheter 12, through adaptor 25, until the distal end of operative catheter 10 is near, but just short of distal end 20 of guiding catheter 12.

#A length of operative catheter 10 extends proximally from the proximal end of guiding catheter 12, with a Y-shaped fitting 26 formed thereon. Fitting 26 has proximal end 34 of guidewire 30 extending therethrough, and inflation port 28 projects at an angle from fitting 26. Inflation fluid is injected into inflation port 28 to inflate an angioplasty balloon on the distal end of operative catheter 10. Fitting 26 functions essentially as the proximal terminal of operative catheter 10, and the proximal end of fitting 26 will be considered, for the purposes of this discussion, to be the proximal end of operative catheter 10.