A delivery system comprises a delivery catheter with a distal capsule which contains a scaffold, a valve and a sleeve in the retracted configuration. The delivery system includes a proximal expandable element provided by an inflatable proximal balloon and a distal expandable element provided by a distal balloon. The proximal balloon provides a temporary seal at the proximal side of the valve. The distal balloon provides a temporary distal seal between a distal olive and a distal end of the sleeve. An inflation fluid is introduced into the sleeve between the proximal and distal balloons the fluid causes the sleeve to expand axially to the expanded deployed configuration. When the sleeve is in the extended deployed configuration the distal balloon is deflated, allowing the olive to detach and travel distally. The rest of the delivery system can then be withdrawn proximally, leaving the implant device in situ.