Occluder with stretchable waist

Occluder, comprising:

• a single continuous tubular braided structure made of an integral base body of at least one wire and having a pitch, said pitch varies along an axial length of the base body with one or more pitch transition sections, the one or more pitch transition sections is fixed along the base body;
• the occluder being heat set to have a post-heat-set shape including:
• a post-heat-set proximal retention element having an outer circumference and a distal inner diameter at a first element-transition section in a relaxed state of the occluder;
• a post-heat-set distal retention element having an outer circumference and a proximal inner diameter at a second element-transition section in the relaxed state of the occluder;
• a post-heat-set intermediate element extending between the first and second element-transition sections of the proximal retention element and the distal retention element,
• wherein the post-heat-set shape transitions integrally along the single continuous tubular braided structure from the proximal retention element to the intermediate element at the first element-transition section, and
• wherein the post-heat-set shape transitions integrally along the single continuous tubular braided structure from the distal retention element to the intermediate element at the second element-transition section,
• wherein the post-heat-set shape of the occluder includes post-heat-set aspects where:
• said pitch varies from a first pitch to a second pitch at a first pitch transition section of said one or more pitch transition sections, wherein the first pitch transition section is located at a fixed pitch transition post-heat-set location on one of said retention elements as a particular retention element,
• the first pitch transition section on the particular retention element is distinct from the respective element-transition section between the intermediate element and the particular retention element,
• wherein the pitch transition post-heat-set location is located closer to a center axis or the intermediate element of said occluder than the outer circumference of the particular retention element when the occluder is in the relaxed state,
• wherein the first pitch transition section is located between the outer circumference and the inner diameter of at least one of the proximal retention element and the distal retention element when the occluder is in the relaxed state,
• wherein the respective element-transition section variably moves along a post-heat-set longitudinal range of the integral base body while the occluder is extended from the relaxed state to the axially extended state,
• the occluder is extendible from the relaxed state to the axially extended state, which is longer in the longitudinal direction of the occluder, than the relaxed state, and wherein the post-heat-set load to extension ratio, measured in N/mm, provided by the occluder is less than about 0.75 when extended at least 2 mm, without distortion of the proximal or distal retention elements, and wherein
• an axial post-heat-set position of at least one of said first and second element- transition sections is axially variable from a first axial position to a second axial position that is closer to a central axis of the occluder, and a diameter of said intermediate element is reduced from a relaxed diameter thereof, when the occluder is extended from the relaxed state to the axially extended state.

A method of manufacturing an occluder, the method comprising:

• forming an integral base body of at least one wire providing a single continuous tubular braided interlaced structure having a pitch, said pitch varies along an axial length of the occluder base body with one or more pitch transition sections, the one or more pitch transition sections is fixed along the base body;
• heat setting the base body to have a post-heat-set shape including:
• a post-heat-set proximal retention element having an outer circumference and a distal inner diameter at a first element-transition section in a relaxed state of the occluder,
• a post-heat-set distal retention element having an outer circumference and a proximal inner diameter at a second element-transition section in the relaxed state of the occluder, and
• a post-heat-set intermediate element extending between the first and second element-transition sections of the proximal retention element and the distal retention element,
• wherein the post-heat-set shape transitions integrally along the single continuous tubular braided structure from the proximal retention element to the intermediate element at the first element-transition section, and
• wherein the post-heat-set shape transitions integrally along the single continuous tubular braided structure from the distal retention element to the intermediate element at the second element-transition section,
• wherein the post-heat-set shape of the occluder includes post-heat-set aspects where:
• said pitch varies from a first pitch to a second pitch at a first pitch transition section of said one or more pitch transition sections, wherein the first pitch transition section is located at a pitch transition post-heat-set location on one of said retention elements as a particular retention element,
• the first pitch transition section on the particular retention element is distinct from the respective element-transition section between the intermediate element and the particular retention element,
• wherein the respective element-transition section variably moves along a post-heat-set longitudinal range of the integral base body while the occluder is extended from the relaxed state to the axially extended state,
• the pitch transition post-heat-set location is closer to the intermediate element or central axis of said occluder than to the outer circumference of the particular retention element when the occluder is in the relaxed state, or wherein the occluder is extendible from the relaxed state to the axially extended state, which is longer in the longitudinal direction of the occluder, than the relaxed state, and wherein the post-heat-set load to extension ratio, measured in N/mm, provided by the occluder is less than about 0.75 when extended at least 2 mm, without distortion of the proximal or distal retention elements,
• the first pitch transition section is located between the outer circumference and the inner diameter of at least one of the proximal retention element and the distal retention element when the occluder is in the relaxed state, and wherein
• an axial post-heat-set position of at least one of said first and second element- transition sections is axially variable from a first axial position to a second axial position that is closer to said central axis when the occluder is extended from the relaxed state to the axially extended state and a diameter of said intermediate element is reduced from a relaxed diameter thereof when the occluder is in the axially extended state.