An apparatus for wrapping a balloon catheter such as an intra-aortic balloon catheter is disclosed. The wrapping apparatus comprises a housing having a channel which receives the balloon membrane of the intra-aortic balloon. The wrapping apparatus also includes a clutching means located in the channel for exerting a predetermined pressure on the balloon membrane to enable the balloon membrane to be wrapped as the wrapping apparatus is rotated relative to the balloon catheter. The clutching means also permits relatively free rotation of the balloon membrane within the wrapping apparatus after the balloon membrane has been wrapped. The clutching means can include a shoe and a biasing means for biasing the shoe towards the balloon membrane with a predetermined pressure while the balloon membrane is being wrapped, yet enable the balloon membrane to rotate relatively freely within the wrapping apparatus after the balloon membrane has been wrapped to a predetermined degree. The clutching means, alternatively, can include flexible vanes projecting inwardly within the channel such that the vanes contact the balloon membrane during wrapping and provide a predetermined pressure onto the balloon membrane which aids in wrapping yet permits the wrapped balloon membrane to rotate relatively freely within the wrapping apparatus.
A balloon catheter for the widening of passages in the body, such as blood vessels, comprises a tubular body connected at one side to the interior of a cylindrical balloon and at another side to a pump unit. The balloon can be enlarged from a first predetermined diameter to a second predetermined diameter without completely withdrawing the catheter from the body passages.
A balloon catheter in which its inflatable and collapsible balloon is of larger diameter than adjacent portions of the catheter body. The balloon defines transition zones at the respective ends which are of fluted shape. Thus, the balloon can assume a collapsed position in which the collapsed transition zones collapse in a substantially star-shaped cross section rather than in a flat-collapsed configuration. Central portions of the catheter follow suit on collapse of the balloon, to avoid the undesired "winging" phenomenon in balloon catheters, particularly PTCA catheters.
An adjustable-length balloon dilatation catheter apparatus and a method for using the same are disclosed wherein an adjustable sheath is externally manipulated to partially surround and contain the dilatation balloon segment of the catheter while the catheter and balloon segment are in situ during a treatment procedure. By sliding the sheath forward or backward to expose a predetermined length of the balloon segment prior to inflating the balloon, the catheter apparatus of this invention is useful in medical procedures requiring balloons of varying lengths.
A stent for reinforcement of the lumen of a peristaltic organ is formed by knitting preferably a nitinol wire into a pattern of overlapping loops selected such that from a relaxed state each row of loops may shift axially relative to and independently of the rows on either side. This local lengthening and shortening accommodate peristalsis of the organ without migrating within the organ. A stent is also shown which comprises two resilient cylindrical mesh layers and a semi-permeable compliant membrane such as expanded polytetrafluoroethylene, sandwiched between. The two mesh layers may be knit of a flexible filament, and the knit may be configured so that the stent can adapt to peristalsis of the body lumen. A method is also shown of manufacturing a delivery system for a resilient tubular device such as a stent so that the device can be inserted into the body in a substantially reduced diameter. The method uses a confining block having a bore and a slot leading into the bore. The tubular device is pinched and inserted into the bore and the slot, two mandrels are inserted into the bore, one inside the device and one outside and the mandrels are revolved about each other to roll the device on itself.
