Sheaths used with polymer scaffolds

An apparatus, comprising:

• a balloon catheter assembly having a distal end and a proximal end, the catheter including a scaffold comprising a polymer crimped to a balloon of the catheter at the catheter distal end;
• a sheath disposed over the scaffold, the sheath applying a radial inward force on the crimped scaffold to limit recoil of the scaffold, the sheath comprising:
• a protecting portion having a distal end, and
• a constraining portion having a distal end, wherein the constraining portion distal end is distal of the catheter distal end;
• wherein the scaffold is crimped by way of plastic deformation of the scaffold to the balloon such that when the sheath is removed the scaffold retains the same diameter it had when disposed within the sheath;
• and
• wherein balloon material is disposed between struts of the scaffold to contribute to a retention force between the plastically deformed scaffold and a surface of the balloon to resist dislodgment of the scaffold from the balloon after the sheath is removed.

An apparatus, comprising:

• a balloon catheter assembly having a distal end and a proximal end, the catheter including a scaffold comprising a polymer crimped to a balloon of the catheter at the catheter distal end;
• a unitary sheath disposed over the scaffold, the sheath applying a radial inward force on the crimped scaffold to limit recoil of the scaffold, the sheath comprising:
• a distal end, and
• a first and second half configured for being separated from each other when the sheath is being removed from the scaffold, and
• wherein the distal end is distal of the catheter distal end;
• wherein the scaffold is crimped by way of plastic deformation of the scaffold to the balloon such that when the sheath is removed the scaffold retains substantially the same diameter it had when disposed within the sheath;
• wherein balloon material is disposed between struts of the scaffold to contribute to a retention force between the plastically deformed scaffold and a surface of the balloon to resist dislodgment of the scaffold from the balloon after the sheath is removed;
• and
• wherein the apparatus is configured into an implantable medical device only after the sheath is removed.

A method of assembly, comprising:

• providing a balloon catheter having a distal end and a proximal end, the catheter including a scaffold comprising a polymer crimped to a balloon of the catheter at the catheter distal end;
• and
• placing a sheath over the crimped scaffold, the sheath comprising:
• a distal end, and
• a first and second half configured for being peeled off when the sheath is removed from the scaffold, and
• wherein the distal end is distal of the catheter distal end;
• the scaffold being crimped to the balloon by way of plastic deformation of the scaffold to the balloon such that balloon material is disposed between struts of the scaffold to provide a retention force between the scaffold and the balloon material to resist dislodgment of the scaffold from the balloon when the sheath is removed, wherein the scaffold crimping includes dwelling the scaffold within a crimp mechanism while the scaffold has an elevated temperature to reduce scaffold recoil.