Catheter system having distal tip for opening obstructions

#The present invention relates to a catheter system for opening a totally or partially occluded blood vessel.

#Arteriosclerosis causes a partial or, in extreme cases, a total blockage of a blood vessel due to a build up of deposits along an inner surface of the blood vessel. The increase in the number of coronary by-pass operations is some indication of the incidence with which the problem is encountered in older patients.

#Prior art proposals recognize that one alternative to bypassing a partially or totally blocked region in a blood vessel is to open or widen the blocked blood vessel. One prior art technique for reopening a blocked blood vessel is to insert a balloon catheter inside the vessel to expand the vessel and either break loose deposits within the vessel or alternatively, increase the size of the lumen passing through those deposits.

#FIG. 1 schematically depicts a distal end of a drive catheter positioned within a guide catheter and approaching a region of total occlusion within a blood vessel;

#FIG. 2 is an elevation view of a proximal end of the FIG. 1 drive catheters;

#FIG. 3 is an enlarged elevation view illustrating both the proximal and distal portions of a drive catheter as the drive catheter is manually rotated by a physician;

#Turning now to the drawings, FIG. 1 schematically illustrates a drive catheter 10 as the drive catheter 10 approaches an obstruction 12 in a blood vessel 14. The drive catheter 10 is inserted into a guide catheter 16 which has been previously inserted by a physician with the aid of an angiographic imaging system (not shown). The guide catheter 16 is conventional and has been utilized in the prior art for positioning balloon catheters within a patient. The imaging system enables the physician to monitor movement of both the guide catheter 16 and drive catheter 10. The obstruction 12 may include calcified (hard) or fatty (soft) deposits that have built up around the blood vessel inner wall. In extreme instances, the blood vessel may be completely blocked so that blood flow through the vessel is entirely cut off. The situation depicted in FIG. 1 is one in which the deposits have built up to completely cut off blood flow through the blood vessel 14.

#While positioning the guide catheter 16, radio-opaque dye is injected through a leur hub 18 (FIG. 2) at the proximal end of the drive catheter 16 through a syringe or the like. To insert the drive catheter 10 the physician disconnects the syringe from the leur hub 18, removes the drive catheter 10 from a sterilized package, and inserts a distal tip 20 (FIG. 1) of the drive catheter 10 into the guide catheter 16. Before it is packaged the catheter 10 is inserted through a tube 21 coupled to a plastic bifurcated "Y" connector 22 having a side-arm branch 23 for injection of fluids. At one end the tube includes a collar 21a having an opening for receipt of the drive catheter 10. A conventional rotating adapter 24 coupled to the "Y" connector 22 has a leur fitting 25 that engages the leur hub 18 of the guide catheter 16. This allows the "Y" connector 22 to rotate while allowing saline/dye solutions to be injected from the side branch.

#Coupled to the side-arm branch 23 is a flexible tube 26 and a conventional leur fitting 27 for injecting fluid into the catheter 16. The leur fitting is used for injecting controlled concentrations of opaque dye and saline solution as the blocked region of the vessel is opened. A seal (not shown) inside the "Y" connector 22 prevents the saline/dye solution that is pumped into the catheter 16 via the side-arm 23 from leaking from the connector 22 into the tube 21.