An implantable medical device includes an inflatable member, a reservoir, a pump attachable between the inflatable member and the reservoir and operable to move fluid from the reservoir to inflate the inflatable member, and a deflation assembly attachable between the pump and the reservoir. The deflation assembly includes a valve that selectively restricts movement of the fluid from the inflatable member to the reservoir, a base and an activation surface opposite the base. The activation surface has an outer peripheral rim surrounding a pad that is movable to displace the valve to allow the fluid to flow from the inflatable member to the reservoir. The pad is recessed relative to the outer peripheral rim such that the outer peripheral rim defines a maxima of the activation surface.