Delivery systems for devices with unsupported structure

A medical device delivery system extending along a longitudinal axis between a proximal end and a distal end, the system comprising:

• an elongate member having a proximal portion and a distal portion;
• a medical device disposed within the elongate member, the medical device comprising a proximal structure, and a distal structure extending distally from a distal end of the proximal structure and having a wall with a proximal terminal end and a distal terminal end, the medical device configured to move from a first position, in which the proximal structure is disposed within the distal portion of the elongate member in a first configuration proximal to the distal structure, to a second position in which the proximal structure extends beyond a distal end of the elongate member and is expanded into a second configuration proximal to the distal structure;
• a plurality of balloons disposed within the distal structure, and between the proximal terminal end of the wall of the distal structure and the distal terminal end of the wall of the distal structure when the medical device is in the first position;
• and
• a fluid delivery lumen having a proximal end configured to fluidly connect to a fluid source and a distal end in fluid communication with the plurality of balloons;
• wherein:
• balloons of the plurality of balloons are in collapsed configurations when the medical device is in the first position;
• and
• the wall of the distal structure is expandable, when the medical device is in the second position, from a first collapsed configuration over the plurality of balloons, into a second, longitudinally expanded configuration by expansion of at least one of the balloons of the plurality of balloons within the distal structure.