Angioplasty balloon for stent deployment

摘要

Prior art balloons on balloon angioplasty catheters (10,15) have two folds to wrap the balloon (16) tightly around a distal portion of the balloon angioplasty catheter (15) prior to balloon inflation. When using such a two-fold balloon (16) to deploy a stent (20) having (as is typical) more than three cells disposed circumferentially around each cylindrical segment of the stent (20), the cells of each segment frequently expand unevenly. That is, after balloon inflation some cells are expanded more than some other cells which is certainly undesirable. The present invention overcomes the disadvantages of prior art devices by utilizing a balloon (52) with three or more folds to more evenly distribute the frictional forces on the inside of the stent (20) during stent deployment thus improving the uniformity of stent cell expansion. Ideally one would like to have the same number of balloon folds (52A,52B,52C,52D,52E) as the number of stent cells distributed circumferentially around the stent (20). Matching the number of balloon folds (52A-52E) to the number of cells of each cylindrical segment of the stent (20) provides better size uniformity for the stent cells after they are expanded against the wall of an artery or some other vessel within a human body.