A system and method for selective masking of stents using an expandable
masking balloon to prevent deposition of therapeutic or protective
coatings on portions of the stent during a coating application process.
An expandable balloon is located within the inner region of a stent, the
balloon is inflated until its outer surface contacts and the inner
surface of the stent lattice in the areas in which the stent coating is
not to be applied, thereby masking the stent inner surface from
deposition of stent coating material during a stent coating process, and
the coating is applied to the remaining exposed surfaces of the stent,
for example by spraying or dipping the stent. The balloon is then
deflated and removed from the coated stent. The balloon may be coated
with, or formed from, a material impregnated with polytetrafluoroethylene
to discourage adherence of the coating material to the balloon's outer
surface in order to minimize coating waste and bridging of stent lattice
openings by coating films.