Method for manufacturing expandable body, method for manufacturing expandable body assembly, and medical device

A method for manufacturing an expandable body assembly comprising:

• cutting out a portion of a base material having a tubular shape to form a plurality of struts extending in an axial direction of the base material and aligned in a circumferential direction around the axial direction and to form, at a second end on a side opposite to a first end in the axial direction of the base material, a fixing portion having a tubular shape and including a second slit along the axial direction and a restricting portion for restricting widening of the second slit, and a ring-shaped connection portion connected to the fixing portion and maintaining the tubular shape of the fixing portion;
• deforming the plurality of struts of the base material in a radial direction using a mold to form an expandable body with a waist portion having a reduced outer diameter in a middle in the axial direction;
• disconnecting the ring-shaped connection portion from the fixing portion and widening the second slit by removing restriction by the restricting portion after forming the expandable body;
• inserting a shaft portion that is elongated into the expandable body;
• and
• after covering a distal part of the shaft portion with the second end, restricting widening of the second slit by the restricting portion and fixing the second end to the distal part of the shaft portion.

A medical device comprising:

• an expandable body including a plurality of struts extending along an axial direction and aligned in a circumferential direction around the axial direction;
• a shaft portion that is long and that is connected to a proximal part of the expandable body;
• the proximal part of the expandable body including a fixing portion having a tubular shape, provided with at least one proximal slit along the axial direction, and capable of opening and closing the proximal slit;
• one of two edges of the fixing portion located across the proximal slit is formed with a protrusion protruding to another edge in the circumferential direction, while the other edge is provided with a recess recessed to be engaged with the protrusion, the proximal slit being formed to include a boundary between the protrusion and the recess;
• the protrusion including a base formed at one end in the circumferential direction, and a top formed on another end in the circumferential direction and longer than the base in the axial direction of the expandable body;
• the recess including an opening top that receives the base of the protrusion and an opening bottom that communicates with the opening top and receives the top of the protrusion;
• the top has a length in the circumferential direction shorter than a length in the circumferential direction of the opening bottom;
• and
• the proximal part of the expandable body is fixed to the shaft portion in a state in which the protrusion is fitted into the recess and a gap in the circumferential direction is formed between the top of the protrusion and the opening bottom of the recess.