Embodiments of the present disclosure are related to devices and techniques for para-valve sealing of an expandable stent-valve implanted using a catheter. In some embodiments, a stent-valve is provided which comprises a seal sleeve/cuff containing material that swells when contacted by blood. A piercing tool may be included and used to permit a user to puncture the sleeve/cuff prior to introduction into a patient's body. In some embodiments, the sleeve/cuff has an integral tubular structure configured to withstand balloon expansion of the stent-valve during or after implantation. In some embodiments, the seal is provided as a separate component from the stent-valve.
