The present invention relates to an improved balloon catheter for insertion in a body passage.
Balloon catheters of various types are known to the art. For example, U.S. Pat. No. 3,435,826 (Fogarty) and U.S. Pat. No. 3,467,101 (Fogarty, et al.) disclose two types of embolectomy catheters used to remove blood clots from blood vessels. As explained in the eariler Fogarty patent, such a catheter is used by first inserting it through an incision into a blood vessel and moving the deflated balloon to a point beyond the clot, then inflating the balloon on the remote side of the clot and withdrawing the catheter. The balloon acts as a drag to push the clot ahead of it until it reaches the incision where it can be readily withdrawn.
The use of such balloon catheters brings with it certain dangers. If excessive transmitted wall pressures and excessive shear stresses are applied to the vessel wall in withdrawing the catheter from the blood vessel, the blood vessel can be seriously damaged or even ruptured. Furthermore, if the balloon or other parts of the catheter fragment while in use, portions of the catheter can become lost in the vessel, thereby creating the danger of obstructions in the vascular system.