A medical device includes a vessel member, a port that couples a compartment interior of the vessel member to a region exterior of the vessel member, and a tubular member that defines a lumen. A distal end of the tubular member is attached to an internal surface of the vessel member within the compartment so that a portion of the internal surface of the vessel member provides a seal at a distal end of the lumen. The tubular member passes through the port, and the proximal end of the tubular member is configured to remain exterior of the compartment. A delivery of a sufficient amount of a filling material into the lumen of the tubular member causes a length of the tubular member to pass through the port and into the vessel compartment.