US 5,489,271 AGranted

Convertible catheter

AssigneeBoston Scientific Corporation

InventorErik C. Andersen

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Abstract

A stylet and hub assembled for stiffening a catheter in rapid exchange mode. The catheter guidewire lumen has a side port associated with a bi-stable guide element that lies across the lumen. A disengageable feature assembly limits insertion of the stylet into the lumen in rapid exchange mode. To convert from rapid exchange mode, disengagement of the disengageable feature enables the stylet to displace the guide element, clearing the guidewire lumen and enabling guidewire or other device to extend throughout the lumen. The stylet has a long proximal portion, a relatively short portion tapering distally to a smaller diameter, and enlarged end. The guide element is formed by plastic deformation of the catheter wall. The disengageable feature is in a removable housing having an end cap that can be replaced with a syringe for flushing liquid along the stylet. A balloon, preferably a PTCA balloon, is mounted on the catheter.

In a catheter assembly comprising a catheter and a stylet, said catheter comprising a shaft having a guidewire lumen extending from proximal to distal regions of the catheter, said catheter suitable for placement alternatively in rapid exchange mode and over-the-wire mode, said catheter having a side port entering into said guidewire lumen at a position in the distal region of the catheter proximal of the distal end of the catheter to enable use in said rapid exchange mode, said catheter having a guide element secured adjacent to the proximal portion of said side port and having first and second positions, in its first said position said guide element extending downwardly across said guidewire lumen in obstructing position to deflect out of the side port a guidewire being inserted into said guidewire lumen through the distal end of the catheter, in its second said position said guide element lying generally along the body of the catheter out of lumen-obstructing position, and said stylet sized during use of the catheter in rapid exchange mode to lie in the proximal portion of said guidewire lumen of said catheter with a distal end of said stylet proximal of said guide element to enhance the pushability of the corresponding portion of said catheter,

the improvement comprising a disengageable stylet stop structure associated with said catheter assembly, said stop structure constructed to limit the distance of insertion of said stylet into said guidewire lumen to a first stylet position in which the distal end of the stylet lies proximal of said guide element for use during said rapid exchange mode, said stop structure being disengageable to permit said stylet to be advanced further into said guidewire lumen to engage said guide element, with said stop structure disengaged, said stylet sized and constructed to enable advancement of said stylet to displace said guide element from its said first position to its said second position after which said stylet can be removed from said guidewire lumen, whereby when it is desired to convert said catheter from rapid exchange mode of use, said stylet can be employed to clear the guidewire lumen.

Abstract

Claims14