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 devices may include a sheath including an open channel configured to accept interventional devices and configured to be inserted into an access channel. The device may include mechanisms for injection of a tissue-stabilizing composition into, around, and/or adjacent to the tissue surrounding the sheath. The device may include at least one energy-transducing element configured to deliver energy to a tissue surrounding the sheath. The energy-transducing element may be configured to heat, shrink and seal the tissue around the sheath. The energy-transducing element may be disposed on an introducer, on a sleeve, or on the sheath. A sealing delivery device for sealing the access channel may be configured to deliver a sealing device into the mechanically enhanced access channel, achieving permanent closure.
