Stent

1. A stent comprising:

a major axis member that includes:

an outer circumferential surface having a tubular shape and an internal space that extends from a front end portion to a base end portion of the outer circumferential surface,

a first opening section provided at the front end portion of the outer circumferential surface, the first opening section being in communication with the internal space, and

a second opening section disposed on the outer circumferential surface, the second opening section being in communication with the internal space; and

an inflow prevention section that has an inflow prevention surface covering the entire second opening section,

the inflow prevention section having a first edge section that is fixed nearer to the base end portion side than the second opening section, and a second edge section that is disposed at a position radially spaced from the outer circumferential surface and radially spaced from the second opening section such that the second edge section extends outward in a radial direction from the second opening section.

2. The stent according to claim 1 , the inflow prevention section further including:

a plurality of bony portions that is arranged in a circumferential direction of the major axis member,

each bony portion having a first end section formed of a material having elasticity and fixed closer to the base end portion than the second opening section, and a second end section extending toward the front end portion in a natural state and radially spaced apart from the outer circumferential surface such that the second end section extends outward in the radial direction; and

membranous portions that have more flexibly than the bony portions and that are formed between the bony portions such that the membranous portions are disposed between at least one set of neighboring bony portions in the circumferential direction from the first end section to the second end section,

wherein the inflow prevention surface covers the second opening section.

3. The stent according to claim 2 , wherein:

the membranous portions are provided between the neighboring bony portions in the circumferential direction of the major axis member around an entire circumference of the major axis member, and

a cutout, which extends from the front end portion to the base end portion and which penetrates through the membranous portion in a thickness direction, is formed in one of the membranous portions.

4. The stent according to claim 1 , wherein the inflow prevention section is disposed around an entire circumference of the major axis member.

5. The stent according to claim 1 , wherein:

the inflow prevention surface extends from a base end, disposed at the base end portion, towards the front end portion,

the inflow prevention surface extends from the outer circumferential surface of the major axis member such that a portion of the inflow prevention surface is spaced radially outward around an entire circumference of the major axis member, and

the second opening section is provided between a bottom section of the inflow prevention surface and the base end portion of the major axis member, and

the second opening section forms a crevice that is covered by the inflow prevention surface.

6. The stent according to claim 5 , further comprising a joint member that is disposed between the distal end of the outer circumferential surface and the base end of the inflow prevention surface,

the joint member extending from a wall section of the base end portion toward the base end,

the joint member being formed in a rod shape,

the joint member connecting the distal end of the outer circumferential surface and the base end, and

the second opening section being formed by the joint member and the major axis member.

7. The stent according to claim 1 , wherein a valve unit, which is formed of a material having elasticity and which has a slit that is closed in a natural state and that elastically deforms to communicate with the internal space, is disposed at the base end portion.

8. The stent according to claim 1 , wherein a sealing member, which is formed of a material having elasticity and which partitions the internal space and the outside of the major axis member, is disposed at the base end portion.

9. The stent according to claim 1 , wherein the second opening section is proximal of a distal end of the outer circumferential surface.