Deployment and dilation with an expandable roll sock delivery system
View Patent ↗An expandable roll sock delivery catheter includes an inner tube, an outer tube having a distal outer tube end, and a medical device, such as a self-expanding stent, collapsibly disposed over the inner tube and concentrically oriented between the inner tube and the outer tube. A hollow tube of expandable balloon material extends from the distal outer tube end, the balloon material being substantially disposed in its entirety within a distal end portion of the outer tube. The balloon material is folded back into the outer tube and over the device as a single layer of balloon material connectively linked to the inner tube proximal to the self-expanding device so as to form an expandable roll sock balloon. The roll sock balloon defines an inflation lumen disposed between the outer tube and inner tube, whereby the inflation lumen is configured for expansion of the roll sock balloon following release of the device.
1. An expandable roll sock delivery system comprising:
an inner tube;
an outer tube;
an expandable medical device collapsibly disposed over the inner tube and concentrically oriented between the inner tube and the outer tube;
a hollow tube of expandable balloon material, including a first balloon material end attached to a distal portion of the outer tube, and a second balloon material end attached to the inner tube, the balloon material extending over an abluminal surface of the device and being substantially disposed within a distal portion of the outer tube in an initial configuration;
wherein the balloon material is attached to the inner and outer tube so as to form an expandable roll sock balloon and an inflation lumen, the inflation lumen being delimited by the space between the outer tube, the roll sock balloon, and the inner tube, wherein the inflation lumen is configured for radial expansion of the roll sock balloon following deployment and release of the expandable medical device by retraction of the outer tube or advancement of the inner tube, the balloon material thereby inverting relative to the initial configuration.
2. The delivery system of claim 1 , wherein a low friction material is integral to or coated onto the roll sock balloon.
3. The delivery system of claim 2 , wherein the low friction material comprises an ultra-high molecular weight polyethylene polymer having a molecular weight between about 1 to about 10 million.
4. The delivery system of claim 2 , wherein the low friction material comprises a coefficient of friction of less than about 0.1.
5. The delivery system of claim 1 , further comprising an atraumatic tip coupled to the distal end of the delivery system.
6. The delivery system of claim 1 , wherein the medical device is a stent.
7. A method for deploying an expandable medical device comprising:
providing the endoluminal medical device delivery system of claim 1 ;
positioning the distal end of the delivery system in a body lumen proximal to a lesion;
retracting the outer tube or extending the inner tube in a manner sufficient for release and radial self-expansion of the medical device;
positioning the delivery system so that the inverted roll sock balloon is within a luminal portion of the expanded medical device;
filling the inflation lumen with an amount of inflation fluid sufficient to radially expand the balloon against the medical device, thereby stabilizing the medical device against one or more walls in the surrounding body lumen.