Method of increasing stent retention of bioabsorbable scaffolding with a sheath

A method of making a stent delivery system, comprising the steps of:

• using a scaffolding made from a polymer having a glass transition temperature (Tg), the scaffolding having a diameter and a plurality of struts;
• providing a catheter comprising a balloon having a deployment diameter;
• mounting the scaffolding on the balloon so as to increase a retention force between the scaffolding and the balloon, including
• reducing the scaffolding diameter from a first size to a second size, wherein the diameter is reduced from the first size to a second size using an iris crimper having crimper jaws that press struts of the scaffolding into a surface of the balloon;
• wherein the scaffolding has an elevated temperature of between Tg and 15 degrees below Tg while the crimper jaws are pressing the strut into the balloon surface;
• and
• forming pillows at ends of the balloon including inflating the balloon while the scaffolding and the balloon are disposed within an expansion restraint;
• deflating the balloon;
• and
• removing the expansion restraint from the scaffolding after deflating the balloon.

A method of making a stent delivery system, comprising the steps of:

• using a scaffolding made from a polymer comprising poly(L-lactide), the scaffolding having a diameter and a plurality of struts;
• providing a catheter comprising a balloon having a deployment diameter;
• mounting the scaffolding on the balloon so as to increase a retention force between the scaffolding and the balloon, including
• using a crimping device, reducing the scaffolding diameter from a first size to a second size,
• removing the scaffolding and the balloon from the device after the scaffolding diameter is reduced to the second size,
• returning the scaffolding and the balloon to the device wherein the scaffolding is aligned between balloon markers,
• reducing the scaffolding diameter to a third size, less than the second size, using the device, wherein the balloon deployment diameter is at least 2.5 times greater than the third size,
• placing the scaffolding and the balloon within an expansion restraint, and
• forming pillows at ends of the balloon including inflating the balloon while the scaffolding and the balloon are within the expansion restraint;
• wherein the expansion restraint is removed from the scaffolding before the scaffolding is placed within a patient.