Polymer scaffold with multi-pleated balloon

A method for making a medical device, comprising the steps of:

• providing a polymer scaffold having a pre-crimp diameter and a pair of ring elements connected to each other by N linking elements, wherein N is greater than or equal to 2;
• placing the scaffold having the pre-crimp diameter over a balloon having at least 2N pleats;
• and
• crimping the scaffold to the balloon, including:
• reducing the scaffold diameter from the pre-crimp diameter to a first diameter,
• wherein the balloon pleats cannot fully open when the scaffold has a diameter equal to or less than the first diameter,
• inflating the balloon not until the scaffold diameter is reduced to the first diameter, and
• reducing the scaffold diameter from the first diameter to a final crimp diameter.

A method for making a medical device, comprising the steps of:

• providing a polymer scaffold made from PLLA and having a pre-crimp diameter;
• crimping the scaffold to a balloon so as to both increase a uniformity of expansion when the scaffold is expanded by the balloon and increase a retention force between the crimped scaffold and balloon, including the steps of
• crimping the scaffold to a balloon having at least six pleats, and
• crimping while the scaffold has an elevated temperature of between 40 and 55 degrees Celsius,
• wherein the balloon has the at least six pleats before the scaffold is crimped to the balloon, and
• wherein the crimping step further includes inflating the balloon only after the scaffold attains a first diameter that is 50% or less than 50% of the pre-crimp diameter.