Method for cold loading an articles
View Patent ↗A method of loading an article, such as a self-expanding stent, into a structure, such as a delivery catheter, including the steps of chilling the article to a predetermined temperature, reducing article size a predetermined amount, inserting fluid into the article, whereby the fluid forms a substantially solid plug with respect to the article, and moving the frozen article. Also provided is an apparatus for loading an article into a structure including: an article size reduction element, a chiller connected to the size reduction element, a cold source communicatively connected to the chiller, and a fluid supply communicatively connected to the size reduction element.
1. A method of loading a stent having a tubular body and a central lumen, into a deployment catheter, comprising the steps of:
a. compressing the stent to a diameter less than the diameter of the lumen of the deployment catheter;
b. applying a support matrix to the stent by cooling the stent to a predetermined cold temperature and applying a fluid to the stent by applying a CO 2 gas to the stent after the stent is cooled to the predetermined temperature, whereby the fluid freezes to form the matrix embedding the stent across the central lumen of the stent;
c. pushing the stent and matrix into the stent deployment catheter lumen, whereby the matrix supports the tubular body of the stent; and
d. removing the matrix from the inserted stent by sublimation.
2. The method of claim 1 , wherein the stent is fragile.
3. The method of claim 1 , wherein the stent has plural shape states.
4. The method of claim 1 , wherein the stent is a self-expanding stent having a predetermined expanded diameter and which is radially compressible to a diameter less than that of the expanded diameter.
5. The method of claim 4 , wherein the self-expanding stent has a predetermined length which is greater than 100 mm.
6. The method of claim 4 , wherein the self-expanding stent has at least first and second shape states, and wherein the self-expanding stent is provided at a first shape state, and wherein the self-expanding stent changes or seeks to change to the second shape state after removing the frozen matrix from the self-expanding stent.
7. The method of claim 6 wherein the self-expanding stent has a predetermined expanded diameter and is radially compressible to a diameter less than that of the expanded diameter, and wherein the stent is provided compressed, at a diameter less than its expanded diameter; and wherein the stent seeks to change to its expanded diameter after removing the frozen matrix from the stent.
8. The method of claim 1 , wherein compressing is crimping.
9. The method of claim 8 , wherein the step of cooling comprises contacting the stent with one or more cooled surfaces for a predetermined time.
10. The method of claim 9 , wherein the cooled surfaces are part of a crimper.
11. The method of claim 10 , wherein the step of crimping is accomplished before fully cooling the stent.
12. The method of claim 1 , wherein the predetermined temperature is equal to or less than −78.5 C, and wherein the matrix comprises frozen CO 2 .
13. The method of claim 4 , wherein the self-expanding stent has a predetermined expanded diameter and the stent deployment catheter lumen has a diameter less than that of the expanded diameter of the stent.
14. The method of claim 1 , wherein the step of removing the matrix from the stent after processing is accomplished by sublimation while the stent is disposed within the stent deployment catheter lumen.