System to assist in the release of a collapsible stent from a delivery device

A method of prosthetic valve delivery, comprising:

• providing an expandable prosthetic valve having a retention member at an end thereof;
• loading the valve into a compartment of a delivery device, the delivery device including a shaft, an elongated sheath surrounding a longitudinal portion of the shaft and slidable in longitudinal directions relative to the shaft, an energy storage element positioned on the longitudinal portion of the shaft, a retainer positioned at one end of the compartment, and a recess in the retainer, the valve being loaded into the compartment with the retention member positioned in the recess and with the valve overlying at least a portion of the energy storage element;
• sliding the sheath in a first one of the longitudinal directions over the valve to radially compress the energy storage element and to hold the energy storage element in a compressed condition;
• inserting the delivery device in a patient to position the valve at a target location;
• and
• sliding the sheath in a second one of the longitudinal directions to uncover the valve, wherein the energy storage element is released from the compressed condition and radially expands to impart an outward radial force to the valve.

A delivery device for an implantable medical device having a retention member at an end thereof, the delivery device comprising:

• a shaft extending in a longitudinal direction and defining a longitudinal axis;
• an elongated sheath surrounding a longitudinal portion of the shaft, the sheath being slidable relative to the shaft in the longitudinal direction;
• a compartment defined inside the sheath and adapted to receive the medical device in an assembled condition;
• a retainer positioned at one end of the compartment, the retainer including a recess adapted to receive the retention member of the medical device in the assembled condition, the recess having a bottom surface located a first distance from the longitudinal axis;
• and
• a balloon extending along at least part of the longitudinal portion of the shaft, the balloon having a deflated state in which an outer surface of the balloon is located a second distance from the longitudinal axis, the second distance being less than the first distance, and the balloon having an inflated state in which the outer surface of the balloon is located a third distance from the longitudinal axis, the third distance being greater than the first distance.

A delivery device for an implantable medical device having a retention member at an end thereof, the retention member having an angled lateral edge, the delivery device comprising:

• a shaft extending in a longitudinal direction and defining a longitudinal axis;
• an elongated sheath surrounding a longitudinal portion of the shaft, the sheath being slidable relative to the shaft in the longitudinal direction;
• a compartment defined inside the sheath and adapted to receive the medical device in an assembled condition;
• and
• a retainer positioned at one end of the compartment, the retainer including a recess adapted to receive the retention member of the medical device in the assembled condition, the retainer having a retention edge facing the compartment and the recess having a first region sized to receive the retention member, the recess including a protuberance defining both a narrowed neck between the first region and the retention edge and an angled sidewall of the first region,
• wherein in the assembled condition, an angle formed between the angled sidewall and the longitudinal axis is greater than an angle formed between the angled lateral edge and the longitudinal axis.