Controlled porosity devices for tissue treatments, methods of use, and methods of manufacture

A balloon comprising:

• a first porous membrane comprising a first microstructure, the first microstructure being configured to inflate to a nominal dimension in response to introduction of a fluid at an inflation pressure and an inflation rate, and resist fluid flow through the first porous membrane at pressures below a threshold perfusion pressure at which perfusion begins;
• and
• a second porous membrane comprising a second microstructure that is different from the first microstructure, the second porous membrane being configured to withstand a hydrostatic load generated by the first membrane upon inflation,
• wherein the threshold perfusion pressure is equal to or greater than the inflation pressure required to achieve the nominal dimension, and
• wherein a terminal pressure, at which a maximum working pressure of the balloon is exceeded, is greater than the threshold perfusion pressure, and at the terminal pressure, a perfusion rate of the first porous membrane is about equal to or greater than the inflation rate,
• wherein the perfusion rate is volume of fluid flowing through pores of the first porous membrane per unit time and the inflation rate is volume of fluid introduced into the first porous membrane per unit time.