Devices, systems and methods are provided for enhancing mechanical strength of tissue, allowing direct and secure access to cardiac and vascular structures, either through tiny incisions or percutaneously. The method for accessing a cardiac chamber or a vascular conduit may include providing an access channel into tissue of the chamber or the conduit. The method may also include providing an energy-transducing element configured to provide heat within the access channel. The method may further include applying energy to the tissue or a tissue-stabilizing composition injected into, around, or adjacent to the tissue to mechanically enhance the access channel.
