Introducer

Abstract

This introducer at least has a housing (10) and a hemostatic valve (4) that is housed in the housing (10). The hemostatic valve (4) has: valve-proximal-end surfaces (46U, 47U) near a proximal end (10P); valve-distal-end surfaces (47R, 48R) near a distal end (10D); and valve-side surfaces (46S, 47S, 48S). The housing has upstream sections (51U, 52U), a downstream section (51R), and side sections (51S, 52S, 53S). The upstream section (52U) has: an end surface (37A) that contacts the valve-proximal-end surface (47U) of the hemostatic valve (4); and a floor surface (39A) that does not contact the valve-proximal-end surface (47U) of the hemostatic valve (4). The downstream section (51R) has: a proximal end (20P) that contacts the valve-distal-end surface (47R) of the hemostatic valve (4); and an end surface that does not contact the valve-distal-end surface (47R) of the hemostatic valve (4).

Description

Introducer

[0001] The present invention relates to an introducer for inserting a medical device into the body.

[0002] As an instrument used when inserting a medical device including a catheter, a guide wire, etc. into the body, an introducer is known. Patent Document 1 discloses a catheter introducer for inserting a catheter into the body. The catheter introducer has a hub connected to the proximal end of the sheath. The hub has a hub body, a presser cap, and a hemostatic valve. The hemostatic valve is disposed in a valve chamber formed by the hub body and the presser cap and closes the insertion hole. The catheter is inserted through the hemostatic valve and extends toward the sheath connected to the distal end of the hub body. The hemostatic valve prevents leakage to the outside of the body such as blood by closely adhering to the catheter.

[0003] Japanese Patent Laid-Open No. 8-168532

[0004] In an introducer, if the adhesion of the hemostatic valve to a medical device (hereinafter referred to as an "inserted body") inserted into the body is increased, the operability of the inserted body by the operator is reduced. Therefore, an introducer that can achieve both the adhesion of the hemostatic valve to the inserted body and the operability of the inserted body is desired.

[0005] An object of the present invention is to provide an introducer that can achieve both the adhesion of the hemostatic valve to the inserted body and the operability of the inserted body.

[0006] The introducer according to the present invention is an introducer for inserting an insertion body into the body, comprising a housing having a through hole formed therein extending from a base end to a tip end, and a hemostatic valve housed in a part of the through hole, wherein when the insertion body is inserted into the introducer, the tip end of the insertion body moves in a first direction from the base end to the tip end through the through hole, the first direction extending parallel to the central axis of the through hole, the hemostatic valve having a valve base end surface and a valve tip surface perpendicular to the first direction, and a valve side surface perpendicular to a second direction which is radially outward with respect to the central axis, the valve base end surface being close to the base end, the valve tip surface being close to the tip end, and the downstream of the first direction being parallel to the first direction The positive direction is indicated, the upstream direction of the first direction is indicated as the negative direction of the first direction, the downstream direction of the second direction is indicated as the positive direction of the second direction, the upstream direction of the second direction is indicated as the negative direction of the second direction, and the housing has an upstream portion that faces the upstream direction of the first direction with respect to the valve base end face of the hemostatic valve, a downstream portion that faces the downstream direction of the first direction with respect to the valve tip face of the hemostatic valve, and a side portion that faces the downstream direction of the second direction with respect to the valve side surface of the hemostatic valve, wherein the upstream portion has an upstream contact surface that contacts the valve base end face and an upstream non-contact surface that does not contact the valve base end face, and the downstream portion has a downstream contact surface that contacts the valve tip face and a downstream non-contact surface that does not contact the valve tip face.

[0007] According to the present invention, the upstream and downstream portions of the housing each have a contact surface that contacts the surface of the hemostatic valve, as well as a non-contact surface that does not contact the surface of the hemostatic valve. Therefore, when an insertion body is inserted into the hemostatic valve, the hemostatic valve can be easily deformed in the upstream and downstream directions in the first direction. Furthermore, the airtightness of the hemostatic valve to the insertion body is well maintained because the upstream and downstream portions of the housing each have contact surfaces. Thus, the introducer can maintain the airtightness of the hemostatic valve to the insertion body while improving the maneuverability of the insertion body by the operator.

[0008] In the present invention, the side portion of the housing may have a lateral contact surface that contacts the valve side surface of the hemostatic valve and a lateral non-contact surface that does not contact the valve side surface. In this case, when an insertion body is inserted into the hemostatic valve, the hemostatic valve can be easily deformed downstream in the second direction. The airtightness of the hemostatic valve to the insertion body is maintained because the side portion of the housing has a lateral contact surface. Therefore, the introducer can further improve the maneuverability of the insertion body by the operator while maintaining the airtightness of the hemostatic valve to the insertion body.

[0009] In the present invention, the valve side surface of the hemostatic valve has a first partial valve side surface and a second partial valve side surface located downstream in the first direction relative to the first partial valve side surface, and the side portion of the housing has a first partial side portion facing downstream in the second direction relative to the first partial valve side surface of the hemostatic valve and a second partial side portion facing downstream in the second direction relative to the second partial valve side surface of the hemostatic valve, and the first partial side portion has a lateral contact surface that contacts the first partial valve side surface of the hemostatic valve and a lateral non-contact surface that does not contact the first partial valve side surface of the hemostatic valve, and the second partial side portion may not have a lateral contact surface that contacts the second partial valve side surface of the hemostatic valve and may have a lateral non-contact surface that does not contact the second partial valve side surface of the hemostatic valve. In this case, when an insertion body is inserted into the hemostatic valve, the portion of the hemostatic valve, particularly the portion downstream in the first direction, can be easily deformed toward the downstream in the second direction. Furthermore, the tight seal of the hemostatic valve against the insertion body is maintained because the first portion of the housing has a lateral contact surface. Therefore, the introducer can further improve the operator's ability to manipulate the insertion body while maintaining the tight seal of the hemostatic valve against the insertion body.

[0010] In the present invention, the upstream non-contact surface of the upstream portion may extend in the circumferential direction around the central axis. In this case, the hemostatic valve can be deformed in the circumferential direction, thereby improving the maneuverability of the insertion body by the surgeon.

[0011] In the present invention, the downstream non-contact surface of the downstream portion may extend in the circumferential direction around the central axis. In this case, the hemostatic valve can be deformed in the circumferential direction, thereby improving the maneuverability of the insertion body by the surgeon.

[0012] In the present invention, the hemostatic valve has a proximal projection that protrudes toward the base end and a tip projection that protrudes toward the tip, and the side portion of the housing has a third portion located downstream in the second direction from the proximal projection of the hemostatic valve and a fourth portion located downstream in the second direction from the tip projection of the hemostatic valve, and the radial distance between the upstream end of the second direction of the fourth portion and the central axis may be shorter than the radial distance between the upstream end of the second direction of the third portion and the central axis. In this case, the fourth portion can prevent the hemostatic valve from moving downstream in the first direction inside the through hole.

[0013] In the present invention, the downstream non-contact surface of the downstream portion has an inclined portion that is inclined with respect to the first direction, and the radial distance between the inclined portion and the central axis may gradually increase toward the first direction. In this case, the inclined portion can cause the hemostatic valve to deform gently toward the downstream direction in the first direction. Therefore, the inclined portion can prevent the hemostatic valve from being damaged due to deformation.

[0014] In the present invention, the boundary portion of the upstream non-contact surface of the upstream part with the upstream contact surface may be curved. In this case, the hemostatic valve can be gently deformed in the curved portion of the upstream part. Therefore, damage to the hemostatic valve due to deformation can be suppressed by the curved portion.

[0015] In the present invention, the upstream portion may have a first projection that protrudes toward the central axis and a second projection that protrudes toward the valve base end face. In this case, the first projection can prevent the hemostatic valve from detaching from the housing.

[0016] In the present invention, the first projection may be located upstream of the second projection in the first direction. In this case, the introducer can stably hold the hemostatic valve while easily removing the insertion body from the hemostatic valve.

[0017] In the present invention, when the inserting body moves in the first direction, a part of the hemostatic valve may deform to move toward the downstream non-contact surface of the downstream portion, and when the inserting body moves in the direction opposite to the first direction, a part of the hemostatic valve may deform to move toward the upstream non-contact surface of the upstream portion. In this case, the introducer can provide good operability when inserting the inserting body into the introducer and when removing the inserting body from the introducer.

[0018] This is a diagram of the introducer sheath 1. This is an exploded perspective view of the introducer 11. This is a cross-sectional view of the main body 2. This is a cross-sectional view of the cap 3. This is a cross-sectional view of the housing 10. This is a perspective view of the hemostatic valve 4. This is a side view of the hemostatic valve 4. This is a bottom view of the hemostatic valve 4. This is a cross-sectional view of the hemostatic valve 4. This is a cross-sectional view of the introducer 11. This is an enlarged view of a part of the cross-sectional view of the introducer 11.

[0019] Embodiments of the present invention will be described with reference to the drawings. The drawings are used to illustrate the technical features that the present invention may adopt. The configurations of the devices described are not intended to limit the invention to those described, but are merely illustrative examples.

[0020] <Overview of Introducer Sheath 1> Introducer sheath 1 is a medical device for safely and accurately inserting medical devices (hereinafter referred to as "insertion devices"), including catheters, dilators, and guidewires, into the body. As shown in Figure 1, introducer sheath 1 has an introducer 11, a shaft 12, a three-way stopcock 13, and a branch pipe 14.

[0021] The introducer 11 is the central component of the introducer sheath 1. The introducer 11 plays a role in preventing blood leakage by the hemostatic valve 4, which will be described later. Details of the introducer 11 will be described later.

[0022] The shaft 12 is connected to the tip of the introducer 11. The shaft 12 includes a base 12A and a soft tip 12B. The base 12A and the soft tip 12B are tubular in shape and have a lumen inside. The soft tip 12B is provided at the tip of the base 12A. The soft tip 12B is softer than the base 12A. The outer diameter of the base 12A and the soft tip 12B is, for example, 3.55 mm. The inner diameter of the base 12A is, for example, 3.05 mm. The inner diameter of the soft tip 12B is, for example, 2.80 mm.

[0023] The connection between the introducer 11 and the vicinity of the base end of the shaft 12 is covered with a reinforcing material 121. A radiopaque marker 122 and a hole 123 are provided near the tip of the shaft 12 and at the base end of the soft tip 12B. The hole 123 penetrates into the lumen of the shaft 12.

[0024] The three-way stopcock 13 is connected to the side of the introducer 11 via a branch pipe 14. The three-way stopcock 13 has a knob 131 for switching the fluid path. The three-way stopcock 13 facilitates the injection of fluid into and the discharge of fluid from the blood vessels.

[0025] <Introducer 11> As shown in Figure 2, the introducer 11 has a housing 10 and a hemostatic valve 4. The hemostatic valve 4 is housed in the housing 10. When the introducer sheath 1 is used, the insertion body is inserted into the introducer 11 by moving downward relative to the housing 10 as shown in Figure 2. The direction of movement of the tip of the insertion body inserted into the introducer 11 is called the "first direction D1". The positive direction in the first direction D1 is called the "downstream direction of the first direction D1". The negative direction in the first direction D1 is called the "upstream direction of the first direction D1". The upstream end of the housing 10 in the first direction D1 is called the "base end 10P". The downstream end of the housing 10 in the first direction D1 is called the "tip end 10D". The shaft 12 is connected to the tip end 10D of the housing 10.

[0026] <Housing 10> As shown in Figures 2 to 5, the housing 10 has a main body 2 (see Figures 2, 3, and 5) and a cap 3 (see Figures 2, 4, and 5). Copolymerized polyester is preferably used for the main body 2 and the cap 3.

[0027] As shown in Figures 2 and 3, the main body 2 has a roughly cylindrical shape. The lumen 2M of the main body 2 extends along the first direction D1. As shown in Figure 3, a hypothetical axis extending parallel to the center of the lumen 2M is called the "central axis C1". The cross-sectional shape when the inner surface 27 of the inner wall forming the lumen 2M is cut by a hypothetical plane perpendicular to the central axis C1 is roughly circular. The radial direction outward from the central axis C1 is called the "second direction D2". The positive direction in the second direction D2 is called the "downstream direction of the second direction D2". The negative direction in the second direction D2 is called the "upstream direction of the second direction D2".

[0028] The main body 2 has a base portion 2A and an extension portion 2B. The outer diameter of the base portion 2A is larger than the outer diameter of the extension portion 2B. The extension portion 2B extends from the downstream end of the base portion 2A in the first direction D1 toward the downstream end of the first direction D1. The downstream end of the extension portion 2B in the first direction D1 corresponds to the tip 10D of the housing 10. The extension portion 2B is covered by a reinforcing material 121 (see Figure 2). The upstream end of the base portion 2A in the first direction D1 is called the "base end 20P". The lumen 2M penetrates the main body 2 between the base end 20P and the tip 10D. The downstream end of the base portion 2A in the second direction D2 is called the "side end 20S".

[0029] The base portion 2A has a branch portion 2C extending in a second direction D2. The lumen 20M of the branch portion 2C extends along the second direction D2. The upstream end of the lumen 20M in the second direction D2 is connected to the lumen 2M of the main body 2. A branch pipe 14 (see Figure 1) is connected to the downstream end of the branch portion 2C in the second direction D2.

[0030] A notch 21 is formed at the downstream end of the base portion 20P in the second direction D2, with a portion of it being cut out. The notch 21 extends in the circumferential direction around the central axis C1. The notch 21 includes surfaces 22 and 23. Surface 22 extends from the side end 20S of the base portion 2A toward the upstream direction D2 and is perpendicular to the first direction D1. Surface 23 extends from the upstream end of surface 22 toward the upstream direction D2 toward the upstream direction D1.

[0031] A recess 25 is formed in surface 23, which is indented toward the upstream direction D2. The portion of surface 23 located downstream of the recess 25 in the first direction D1 is called "partial surface 24". The portion of surface 23 located upstream of the recess 25 in the first direction D1 is called "partial surface 26". Partial surface 26 is inclined with respect to the first direction D1. The angle θ that partial surface 26 makes with respect to the first direction D1 is, for example, 25 degrees. The radial distance between partial surface 26 and the central axis C1 gradually increases from upstream to downstream in the first direction D1.

[0032] As shown in Figure 4, the cap 3 has a roughly cylindrical shape. The lumen 3M of the cap 3 extends along the first direction D1. A hypothetical axis extending parallel to the first direction D1 through the center of the lumen 3M is called the "central axis C1," as in the case of the main body 2. The radial direction outward from the central axis C1 is called the "second direction D2," as in the case of the main body 2.

[0033] The upstream end of the cap 3 in the first direction D1 corresponds to the base end 10P of the housing 10. The downstream end of the cap 3 in the first direction D1 is called the "tip 30D". The lumen 3M penetrates the cap 3 from the base end 10P to the tip 30D. The downstream end of the cap 3 in the second direction D2 is called the "side end 30S".

[0034] The lumen 3M includes partial lumens 31M and 32M with different inner diameters. The partial lumens 31M and 32M are aligned in the first direction D1. Partial lumen 32M is located downstream of partial lumen 31M in the first direction D1. The inner diameter of partial lumen 32M is larger than the inner diameter of partial lumen 31M.

[0035] A first projection 36 is provided near the downstream end in the first direction D1 of the inner surface 31 of the inner wall forming the partial lumen 31M. The first projection 36 protrudes from the inner surface 31 toward the upstream in the second direction D2. The first projection 36 extends circumferentially around the central axis C1. The width of the first projection 36 in the first direction D1 gradually decreases toward the upstream in the second direction D2. The downstream end face 36A of the first projection 36 in the first direction D1 is perpendicular to the first direction D1.

[0036] A third projection 38 is provided on the inner surface 32 of the inner wall forming the partial lumen 32M. The third projection 38 protrudes from the inner surface 32 upstream in the second direction D2. The third projection 38 extends circumferentially around the central axis C1. The upstream end of the third projection 38 in the second direction D2 is curved.

[0037] An inner surface 33 is interposed between the downstream end of the inner surface 31 in the first direction D1 and the upstream end of the inner surface 32 in the first direction D1. The inner surface 33 is provided with a second projection 37 and a groove 39.

[0038] The second projection 37 protrudes from the inner surface 33 downstream in the first direction D1. The second projection 37 extends circumferentially around the central axis C1. The second projection 37 is located downstream of the first projection 36 in the first direction D1.

[0039] Of the downstream end of the second projection 37 in the first direction D1, the end face 37A, excluding both the upstream and downstream ends in the second direction D2, is perpendicular to the first direction D1. Of the downstream end of the second projection 37 in the first direction D1, both ends excluding the end face 37A are curved. Of the downstream end of the second projection 37 in the first direction D1, the portion downstream of the end face 37A in the second direction D2 is called the "curved portion 37B". Of the downstream end of the second projection 37 in the first direction D1, the portion upstream of the end face 37A in the second direction D2 is called the "curved portion 37C". The curvature of the curved portion 37B is, for example, R0.2 (1 / mm). The curvature of the curved portion 37C is, for example, R0.3 (1 / mm). The curvature of the curved portion 37C is greater than the curvature of the curved portion 37B.

[0040] The end face 370 upstream in the second direction D2 of the second protruding portion 37 extends from the curved portion 37C toward the end portion downstream in the second direction D2 of the end face 36A of the first protruding portion 36. The end face 370 is orthogonal to the second direction D2. The end face 370 extends across the circumferential direction centered on the central axis C1.

[0041] The groove portion 39 is formed in a portion of the inner surface 33 sandwiched between the second protruding portion 37 and the inner surface 32 in the second direction D2. The groove portion 39 is recessed toward the upstream in the first direction D1. The bottom surface 39A of the groove portion 39 is located upstream in the first direction D1 with respect to the end face 37A of the second protruding portion 37. The groove portion 39 and the bottom surface 39A extend across the circumferential direction centered on the central axis C1. The distance in the first direction D1 between the end face 37A and the bottom surface 39A corresponds to the depth of the groove portion 39. The depth of the groove portion 39 is, for example, about 0.3 mm.

[0042] As shown in FIG. 5, the vicinity of the end portion downstream in the first direction D1 of the cap 3 enters the notch 21 of the main body 2. Thereby, the cap 3 is fitted to the main body 2, and the housing 10 is formed.

[0043] In a state where the cap 3 is fitted to the main body 2, the positions of the respective central axes C1 of the main body 2 and the cap 3 coincide. The respective central axes C1 of the main body 2 and the cap 3 form the central axis C of the housing 10. The inner cavity 2M of the main body 2 and the inner cavity 3M of the cap 3 are integrated to form a through hole 10M. The central axis C passes through the center of the through hole 10M. The through hole 10M extends along the first direction D1 between the proximal end 10P of the cap 3 and the distal end 10D of the main body 2 and penetrates the housing 10.

[0044] In a state where the cap 3 is fitted to the main body 2, the distal end 30D of the cap 3 contacts the surface 22 of the main body 2. The inner surface 32 of the cap 3 contacts a partial surface 24 of the main body 2. The third protruding portion 38 of the cap 3 engages with the recess 25 of the main body 2, thereby preventing the cap 3 from detaching from the main body 2.

[0045] The partial surface 26 of the main body 2 is spaced upstream in the second direction D2 from the inner surface 32 of the cap 3. Among the inner surface 32 of the cap 3, the portion located downstream in the second direction D2 with respect to the partial surface 26 of the main body 2 is referred to as the "partial inner surface 32B". Among the inner surface 32 of the cap 3, the portion upstream in the first direction D1 from the partial inner surface 32B is referred to as the "partial inner surface 32A".

[0046] A groove portion 16 is formed between the partial surface 26 of the main body 2 and the partial inner surface 32B of the cap 3. The groove portion 16 extends in the circumferential direction centered on the central axis C. The distance in the first direction D1 between the proximal end 20P and the end portion downstream in the first direction D1 of the partial surface 26 corresponds to the depth of the groove portion 16. The depth of the groove portion 16 is, for example, about 0.3 mm.

[0047] The inner surface 27 of the main body 2 is located upstream in the second direction D2 with respect to the end face 370 of the cap 3. The radial distance between the central axis C and the inner surface 27 is shorter than the radial distance between the central axis C and the end face 370.

[0048] <Hemostatic valve 4> As shown in FIGS. 6 to 9, the hemostatic valve 4 has a plate-shaped base portion 40. The base portion 40 has a circular shape in plan view. An axis passing through the center of the base portion 40 and perpendicular to the base portion 40 is referred to as the "central axis C2". When the hemostatic valve 4 is housed in the housing 10 (see FIG. 5), the positions of the central axis C of the housing 10 and the central axis C2 respectively coincide. The lower side in FIGS. 6, 7, and 9 corresponds to the first direction D1 in the housing 10 in which the hemostatic valve 4 is housed. The left and right sides in FIGS. 7 and 9 correspond to the second direction D2 in the housing 10 in which the hemostatic valve 4 is housed.

[0049] The base portion 40 has a hole 4H in a portion overlapping with the central axis C2. The cross-sectional shape when the hole 4H is cut by a virtual plane perpendicular to the central axis C2 is circular.

[0050] As shown in FIG. 6, a protrusion 4A is provided on the upstream surface 4U in the first direction D1 of the two surfaces perpendicular to the central axis C2 of the hemostatic valve 4. The protrusion 4A protrudes upstream in the first direction D1 from the surface 4U. The protrusion 4A has a substantially circular shape in plan view.

[0051] Three grooves 4G are formed in the projection 4A, extending from the central axis C2 in a second direction D2. The three grooves 4G are arranged at equal intervals in the circumferential direction with respect to the central axis C2. The projection 4A is divided into partial projections 41A, 42A, and 43A by the three grooves 4G. The partial projections 41A, 42A, and 43A have a sector shape in plan view. The central angle, radius, and arc length of each of the partial projections 41A, 42A, and 43A are the same.

[0052] The upstream surfaces of each of the partial protrusions 41A, 42A, and 43A in the first direction D1 are perpendicular to the first direction D1. The downstream surfaces of each of the partial protrusions 41A, 42A, and 43A in the second direction D2 are perpendicular to the second direction D2. As shown in Figure 9, the upstream surface of the protrusion 4A in the first direction D1 is called the "valve base end surface 46U". The downstream surface of the protrusion 4A in the second direction D2 is called the "valve side surface 46S".

[0053] As shown in Figures 7 and 8, partial protrusions 41B, 42B, and 43B are provided on the downstream surface 4R in the first direction D1 of the two surfaces perpendicular to the central axis C2 of the hemostatic valve 4. The partial protrusions 41B, 42B, and 43B each extend linearly along the second direction D2 downstream from the central axis C2. The partial protrusions 41B, 42B, and 43B are arranged at equal intervals in the circumferential direction with respect to the central axis C2.

[0054] The downstream surfaces of each of the partial protrusions 41B, 42B, and 43B in the first direction D1 are perpendicular to the first direction D1. The downstream surfaces of each of the partial protrusions 41B, 42B, and 43B in the second direction D2 are perpendicular to the second direction D2. The partial protrusions 41B, 42B, and 43B are collectively referred to as "protrusion 4B". As shown in Figure 9, the downstream surface of the protrusion 4B in the first direction D1 is called the "valve tip surface 48R". The downstream surface of the protrusion 4B in the second direction D2 is called the "valve side surface 48S".

[0055] The valve side surface 48S of the projection 4B is located upstream in the second direction D2 from the valve side surface 46S of the projection 4A. The radial distance between the central axis C2 and the valve side surface 48S is shorter than the radial distance between the central axis C2 and the valve side surface 46S.

[0056] In the circumferential direction with respect to the central axis C2, the positions of the angle bisectors of the central angles of the partial protrusions 41A and 41B coincide, the positions of the angle bisectors of the central angles of the partial protrusions 42A and 42B coincide, and the positions of the angle bisectors of the central angles of the partial protrusions 43A and 43B coincide (see Figure 7).

[0057] Of the surface 4U of the base 40, the portion located downstream of the projection 4A in the second direction D2 is called the "valve base end surface 47U". Of the surface 4R of the base 40, the portion located downstream of the projection 4B in the second direction D2 is called the "valve tip surface 47R". Of the base 40, the portion located downstream of the projections 4A and 4B in the second direction D2 is called the "partial base 4C". The distance in the first direction D1 between the valve base end surface 47U and the valve tip surface 47R corresponds to the thickness of the partial base 4C. The thickness of the partial base 4C is approximately 1.28 mm as an example. Of the partial base 4C, the surface downstream of the second direction D2 is called the "valve side surface 47S".

[0058] <Assembly of the hemostatic valve 4 to the housing 10> The hemostatic valve 4 is held at the base end 20P of the main body 2. In this state, the cap 3 is fitted onto the main body 2. As a result, the hemostatic valve 4 is housed in the housing 10. As shown in Figure 10, the hemostatic valve 4 housed in the housing 10 is positioned in the through hole 10M of the housing 10, more specifically, in a part of the partial lumen 32M of the cap 3 (see Figure 5). The position of the central axis C2 of the hemostatic valve 4 coincides with the position of the central axis C of the housing 10. The valve base end faces 46U and 47U of the hemostatic valve 4 are close to the base end 10P of the housing 10, and the valve tip faces 47R and 48R are close to the tip 10D of the housing 10.

[0059] The projection 4A of the hemostatic valve 4 is positioned downstream in the first direction D1 from the first projection 36 of the cap 3, and upstream in the second direction D2 from the second projection 37 of the cap 3. The projection 4B of the hemostatic valve 4 is positioned upstream in the second direction D2 from the portion of the main body 2 near the base end 20P. The partial base 4C of the hemostatic valve 4 is positioned downstream in the first direction D1 from the second projection 37 and groove 39 of the cap 3, and upstream in the first direction D1 from the portion of the main body 2 near the base end 20P.

[0060] The partial base 4C of the base 40 of the hemostatic valve 4 is compressed by forces from upstream and downstream in the first direction D1 by the main body 2 and the cap 3. As shown in Figure 11, as it is compressed, a portion of the partial base 4C of the hemostatic valve 4 downstream in the second direction D2 and downstream in the first direction D1 deforms so as to fit into the groove 16 along the partial surface 26. The portion of the hemostatic valve 4 that fits into the groove 16 is called the "deformed portion 45". The end face of the deformed portion 45 downstream in the second direction D2 is called the "valve side surface 471S". The end face of the deformed portion 45 downstream in the first direction D1 is called the "valve tip surface 471R". The portion of the partial surface 26 of the main body 2 that contacts the valve tip surface 471R of the deformed portion 45 is called the "contact surface 26A". The portion of the partial surface 26 of the main body 2 that does not contact the valve tip surface 471R of the deformed portion 45 is called the "non-contact surface 26B".

[0061] As shown in Figure 10, the portion of the cap 3 that faces upstream in the first direction D1 relative to the valve base end face 46U of the protruding portion 4A of the hemostatic valve 4 is called the "upstream portion 51U". The portion of the cap 3 including the first protruding portion 36 corresponds to the upstream portion 51U. The end face 36A of the upstream portion 51U contacts the valve base end face 46U of the hemostatic valve 4.

[0062] The portion of the cap 3 that faces downstream in the second direction D2 relative to the valve surface 46S of the protruding portion 4A of the hemostatic valve 4 is called the "side portion 51S". The portion of the cap 3 near the upstream end in the second direction D2 corresponds to the side portion 51S. The end face 370 of the side portion 51S contacts the valve surface 46S of the hemostatic valve 4. The curved portion 37C of the side portion 51S does not contact the valve surface 46S of the hemostatic valve 4.

[0063] The portion of the cap 3 that faces upstream in the first direction D1 relative to the valve base end face 47U of the partial base 4C of the hemostatic valve 4 is called the "upstream portion 52U". The portion of the cap 3 including the second projection 37 and the groove 39 corresponds to the upstream portion 52U. The end face 37A of the upstream portion 52U contacts the valve base end face 47U of the hemostatic valve 4. The curved portions 37B and 37C of the upstream portion 52U, and the bottom surface 39A of the groove 39 do not contact the valve base end face 47U of the hemostatic valve 4.

[0064] Of the cap 3, the portion facing downstream in the second direction D2 with respect to the valve sides 47S and 471S of the partial base 4C of the hemostatic valve 4 shown in Figure 11 is called the "side portion 52S". The partial inner surface 32A of the side portion 52S is in contact with the valve side 47S of the hemostatic valve 4. The partial inner surface 32B of the side portion 52S is not in contact with the valve side 471S of the hemostatic valve 4.

[0065] Of the main body 2, the portion facing downstream in the first direction D1 with respect to the valve tip surfaces 47R and 471R of the partial base portion 4C of the hemostatic valve 4 is called the "downstream portion 51R". The portion of the main body 2 near the base end 20P corresponds to the downstream portion 51R. The base end 20P of the downstream portion 51R contacts the valve tip surface 47R of the hemostatic valve 4. The contact surface 26A of the downstream portion 51R contacts the valve tip surface 471R of the hemostatic valve 4. The non-contact surface 26B of the downstream portion 51R does not contact the valve tip surfaces 47R and 471R of the hemostatic valve 4.

[0066] Of the main body 2, the portion facing downstream in the second direction D2 with respect to the valve side surface 48S of the protruding portion 4B of the hemostatic valve 4 is called the "side portion 53S". Of the inner surface 27 of the main body 2, the portion located downstream in the second direction D2 with respect to the protruding portion 4B of the hemostatic valve 4 is called the "partial inner surface 27A". The partial inner surface 27A of the side portion 53S does not come into contact with the valve side surface 48S of the hemostatic valve 4.

[0067] Furthermore, the radial distance between the central axis C and the partial inner surface 27A of the side portion 53S is shorter than the radial distance between the central axis C and the end face 370 of the side portion 51S. Consequently, the radial distance between the upstream end (end face 370) of the side portion 51S in the second direction D2 and the central axis C is shorter than the radial distance between the upstream end (partial inner surface 27A) of the side portion 53S in the second direction D2 and the central axis C.

[0068] <Method of Use> First, the operator inserts the dilator from the opening at the proximal end 10P of the introducer 11 toward the through hole 10M. The outer diameter of the inserted dilator is, for example, 2.84 mm. The operator advances the dilator in the first direction D1. The tip of the dilator moves in the first direction D1 within the through hole 10M from the proximal end 10P toward the tip 10D. At this time, the dilator passes through the hole 4H of the hemostatic valve 4.

[0069] The hemostatic valve 4 receives a force in the first direction D1 due to the frictional force between it and the dilator. The deformable portion 45 of the hemostatic valve 4 deforms and moves in a direction that brings it closer to the non-contact surface 26B of the downstream portion 51R of the introducer 11 and the partial inner surface 32B of the side portion 52S. The hemostatic valve 4 also deforms and moves in a direction that brings the valve side surface 48S of the hemostatic valve 4 closer to the partial inner surface 27A of the side portion 53S of the introducer 11. As a result, the force required by the operator to inflate the dilator is reduced compared to when the hemostatic valve 4 does not deform.

[0070] The dilator moves further in the first direction D1. The tip of the dilator protrudes from the opening 10D of the tip 11 toward the lumen of the shaft 12. The dilator passes through the lumen of the base 12A and the soft tip 12B of the shaft 12. The outer diameter of the dilator is smaller than the inner diameter of the base 12A and larger than the inner diameter of the soft tip 12B. Therefore, as the dilator passes through the lumen of the soft tip 12B, it moves in the first direction D1 while increasing the inner diameter of the soft tip 12B. The tip of the dilator protrudes from the opening at the tip of the shaft 12 toward the outside of the shaft 12. The step difference at the boundary between the soft tip 12B and the protruding dilator is smaller than when the dilator does not increase the inner diameter of the soft tip 12B. The operator stops advancing the dilator.

[0071] Next, the surgeon inserts a guidewire into the body. After inserting the guidewire, the surgeon guides the introducer sheath 1 and the dilator into the body along the guidewire while passing the guidewire through the lumen of the dilator. The surgeon can confirm the position of the tip of the shaft 12 inside the body using the radiopaque marker 122 on the shaft 12.

[0072] When the tip of the shaft 12 reaches the vicinity of the affected area inside the body, the operator stops advancing the introducer sheath 1.

[0073] Furthermore, the end face 36A of the upstream portion 51U, the end face 370 of the side portion 51S, the end face 37A of the upstream portion 52U, the partially inner surface 32A of the side portion 52S, the base end 20P of the downstream portion 51R, and the contact surface 26A of the introducer 11 are in contact with the valve base end faces 46U, 47U, valve side faces 47S, valve tip faces 47R, 471R of the hemostatic valve 4. Therefore, the airtightness of the hemostatic valve 4 to the dilator is maintained during the above process.

[0074] Next, the surgeon withdraws the guidewire and dilator from the introducer sheath 1. The dilator moves in the opposite direction to the first direction D1. At this time, the hemostatic valve 4 receives a force in the opposite direction to the first direction D1 due to the frictional force between it and the dilator. The hemostatic valve 4 deforms and moves so that a part of the hemostatic valve 4 approaches the curved portions 37B, 37C and the bottom surface 39A of the groove portion 39 of the upstream portion 52U of the introducer 11. As a result, the force required by the surgeon to withdraw the dilator is reduced compared to when the hemostatic valve 4 is not deformed. Finally, the guidewire and dilator are removed from the body.

[0075] Next, the technician inserts the catheter through the opening at the proximal end 10P of the introducer 11. The catheter moves in the first direction D1. The tip of the catheter passes through the through-hole 10M of the introducer 11, the hole 4H of the hemostatic valve 4, and the lumen of the shaft 12. The tip of the catheter protrudes out of the shaft 12 through the opening at the tip of the shaft 12. The technician stops advancing the catheter. In this state, the technician treats the affected area with the catheter. After the treatment of the affected area with the catheter is complete, the technician withdraws the catheter from the introducer sheath 1.

[0076] Next, the operator inserts the dilator and guidewire into the introducer sheath 1. The behavior of the hemostatic valve 4 of the introducer 11 relative to the dilator is the same as when inserting the dilator into the introducer 11 outside the body, so the explanation is omitted. The force required by the operator to advance the dilator is weaker compared to when the hemostatic valve 4 is not deformed.

[0077] Next, the operator withdraws the dilator and introducer sheath 1. The dilator and introducer sheath 1 move along the guidewire and are eventually removed from the body. Finally, the operator removes the guidewire from the body.

[0078] <Operation and Effects of This Embodiment> The upstream portion 52U of the housing 10 has curved portions 37B, 37C and a bottom surface 39A that do not come into contact with the hemostatic valve 4. The downstream portion 51R of the housing 10 has a non-contact surface 26B that does not come into contact with the hemostatic valve 4. Therefore, when inserting the dilator into the hemostatic valve 4 or removing the dilator from the hemostatic valve 4, the hemostatic valve 4 can be easily deformed in the upstream and downstream directions of the first direction D1. Therefore, the introducer 11 can improve the operability of the dilator by the operator. Note that the hemostatic valve 4 comes into contact with the end surface 36A of the upstream portion 51U, the end surface 37A of the upstream portion 52U, the base end 20P of the downstream portion 51R and the contact surface 26A of the housing 10, so the airtightness of the hemostatic valve 4 to the dilator is maintained. Therefore, the introducer 11 can prevent blood from leaking out of the body through the gap between the dilator and the hemostatic valve 4 by maintaining the tight seal of the hemostatic valve 4 against the dilator.

[0079] The side portion 51S of the housing 10 has a curved portion 37C that does not come into contact with the hemostatic valve 4. The side portion 52S of the housing 10 has a partial inner surface 32B that does not come into contact with the hemostatic valve 4. The side portion 53S of the housing 10 has a partial inner surface 27A that does not come into contact with the hemostatic valve 4. Therefore, when inserting the dilator into or removing the dilator from the hemostatic valve 4, the hemostatic valve 4 can be easily deformed in the upstream and downstream directions of the first direction D1. As a result, the introducer 11 can improve the operability of the dilator by the operator. Since the hemostatic valve 4 comes into contact with the end face 370 of the side portion 51S and the partial inner surface 32A of the side portion 52S of the housing 10, the airtightness of the hemostatic valve 4 to the dilator is maintained. Therefore, by maintaining the airtightness of the hemostatic valve 4 to the dilator, the introducer 11 can suppress blood leakage from the body through the gap between the dilator and the hemostatic valve 4.

[0080] The side portion 51S of the housing 10 has an end face 370 that contacts the hemostatic valve 4 and a curved portion 37C that does not contact the hemostatic valve 4. The side portion 52S of the housing 10 has a partial inner surface 32A that contacts the hemostatic valve 4 and a partial inner surface 32B that does not contact the hemostatic valve 4. On the other hand, the side portion 53S of the housing 10 located downstream of the side portions 51S and 52S in the first direction D1 does not have a surface that contacts the hemostatic valve 4, and only has a partial inner surface 27A that does not contact it. Therefore, when a dilator is inserted into the hemostatic valve 4, the portion of the hemostatic valve 4, especially the portion downstream in the first direction D1, can be easily deformed toward the downstream in the second direction D2. The airtightness of the hemostatic valve 4 to the dilator is maintained by the end face 370 and the partial inner surface 32A that contact the hemostatic valve 4. Therefore, the introducer 11 can further improve the operator's ability to manipulate the dilator while maintaining the tight seal of the hemostatic valve 4 against the dilator.

[0081] The bottom surface 39A of the upstream portion 52U of the housing 10 extends circumferentially around the central axis C. Therefore, the introducer 11 can deform the hemostatic valve 4 circumferentially toward the upstream direction D1. As a result, the introducer 11 can provide particularly good operability for the operator when removing the dilator from the body.

[0082] The non-contact surface 26B of the downstream portion 51R of the housing 10 extends circumferentially around the central axis C. Therefore, the introducer 11 can deform the hemostatic valve 4 downstream in the first direction D1 over the circumferential direction. As a result, the introducer 11 can provide particularly good operability for the operator when inserting the dilator into the body.

[0083] The radial distance between the upstream end (end face 370) of the side portion 51S in the second direction D2 and the central axis C is shorter than the radial distance between the upstream end (partial inner surface 27A) of the side portion 53S in the second direction D2 and the central axis C. In this case, the side portion 53S can prevent the hemostatic valve 4 from moving downstream in the first direction D1 inside the through hole 10M.

[0084] The non-contact surface 26B of the downstream portion 51R is inclined with respect to the first direction D1. The radial distance between the non-contact surface 26B and the central axis C gradually increases toward the downstream direction D1. This makes the degree of deformation when the partial base portion 4C of the hemostatic valve 4 deforms while in contact with the non-contact surface 26B to form the deformed portion 45 less severe compared to when the non-contact surface 26B is not inclined with respect to the first direction D1. Therefore, the introducer 11 can prevent the hemostatic valve 4 from being damaged due to deformation by inclining the non-contact surface 26B.

[0085] Furthermore, during the manufacturing process of the introducer 11, when the cap 3 is fitted onto the main body 2, the manufacturer moves the tip 30D of the cap 3 downstream in the first direction D1 along the partial surface 26. In this case, the inner diameter of the tip 30D of the cap 3 is widened by the partial surface 26, so the manufacturer can easily fit the cap 3 onto the main body 2.

[0086] In the upstream portion 52U, a curved portion 37B is provided in the portion adjacent to the end face 37A that contacts the hemostatic valve 4, and this portion does not come into contact with the hemostatic valve 4. This allows the portion of the hemostatic valve 4 that is close to the curved portion 37B to deform more gradually compared to a case where the curved portion 37B is not curved. In this case, the curved portion 37B can prevent the hemostatic valve 4 from being damaged due to deformation.

[0087] The upstream portion 52U has a first projection 36 that protrudes toward the central axis C and a second projection 37 that protrudes toward the valve base end face 47U of the hemostatic valve 4. In this case, the first projection 36 can prevent the hemostatic valve 4 from detaching from the housing 10 by moving upstream in the first direction D1 relative to the housing 10. The second projection 37 can properly hold the hemostatic valve 4 in the housing 10.

[0088] The first projection 36 is located upstream of the second projection 37 in the first direction D1. This allows the force acting on the first projection 36 when the dilator is moved upstream of the hemostatic valve 4 in the first direction D1 to be weakened by the second projection 37. Therefore, the introducer 11 can stably hold the hemostatic valve 4 while easily removing the dilator from the hemostatic valve 4.

[0089] During the process of inserting the dilator into the introducer 11, the hemostatic valve 4 deforms and moves in a direction in which the deformed portion 45 of the hemostatic valve 4 approaches the non-contact surface 26B of the downstream portion 51R and the partially inner surface 32B of the side portion 52S. On the other hand, during the process of removing the dilator from the introducer 11, the hemostatic valve 4 deforms and moves in a direction in which a part of the hemostatic valve 4 approaches the curved portions 37B and 37C of the second protrusion 37 of the upstream portion 52U and the bottom surface 39A of the groove portion 39. Therefore, the introducer 11 can provide good operability both when inserting the dilator and when removing the dilator.

[0090] A shaft 12 with a smaller outer diameter and a larger inner diameter is desired. However, if the outer diameter of the shaft 12 is made smaller and the inner diameter is made larger, kinking of the shaft 12 becomes more likely, especially when inserting or removing a dilator from the shaft 12.

[0091] In contrast, the introducer 11 makes the hemostatic valve 4 more easily deformable in the upstream and downstream directions of the first direction D1, thereby reducing the force applied from the dilator to the introducer 11 when the operator inserts or removes the dilator. This suppresses the occurrence of kinks in the shaft 12, while allowing the use of a shaft 12 with a smaller outer diameter and a larger inner diameter.

[0092] <Modifications> The present invention is not limited to the above embodiments, and various modifications are possible. In the above embodiments, the case in which the inserting body inserted into the introducer 11 is a dilator is illustrated. The inserting body inserted into the introducer 11 is not limited to a dilator, but may be a catheter, guidewire, etc. In this case, the inserting body may be inserted into or removed from the body while the shaft 12 of the introducer sheath 1 is inside the body. The introducer 11 can be made easier for the operator to handle by deforming the hemostatic valve 4 when inserting or removing a catheter and guidewire.

[0093] The hemostatic valve 4 may have a slit formed around the hole 4H. The hemostatic valve 4 does not necessarily have a hole 4H. For example, the hemostatic valve 4 may have a hole formed when the dilator is first inserted.

[0094] In addition to the grooves 39 and 16, a groove may also be provided on the end face 36A of the first projection 36. The bottom of this groove may be spaced upstream in the first direction D1 from the valve base end face 46U of the hemostatic valve 4. This groove may extend in the circumferential direction around the central axis C.

[0095] The second projection 37 does not necessarily have to have a curved portion 37C. The side portion 51S has only an end face 370 that contacts the valve side surface 46S of the hemostatic valve 4, and does not have to have a surface that does not contact it. Part or all of the partial inner surface 27A of the side portion 53S may contact the valve side surface 48S of the hemostatic valve 4.

[0096] The positions of the end face 370 of the side portion 51S and the partial inner surface 27A of the side portion 53S in the second direction D2 may be the same. In this case, the distance in the second direction D2 between the end face 370 of the side portion 51S and the central axis C may be the same as the distance in the second direction D2 between the partial inner surface 27A of the side portion 53S and the central axis C. Alternatively, the distance in the second direction D2 between the end face 370 of the side portion 51S and the central axis C may be shorter than the distance in the second direction D2 between the partial inner surface 27A of the side portion 53S and the central axis C.

[0097] At least one of the grooves 39 and 16 does not have to extend in the circumferential direction around the central axis C. In this case, at least one of the grooves 39 and 16 may be divided in a part of the circumferential direction around the central axis C. Instead of the grooves 39 and 16, one or more recesses having a circular or rectangular opening may be provided. At least one of the first projection 36 and the second projection 37 does not have to extend in the circumferential direction around the central axis C. In this case, at least one of the first projection 36 and the second projection 37 may be divided in a part of the circumferential direction around the central axis C.

[0098] Instead of at least one of the curved portions 37B and 37C of the second projection 37, an inclined portion that is inclined with respect to the first direction D1 may be provided. Alternatively, instead of at least one of the curved portions 37B and 37C of the second projection 37, an end face that extends in the first direction D1 may be provided. The boundary portion between the base end 20P of the main body 2 of the housing 10 and the contact surface 26A may be curved.

[0099] The cap 3 may have only one of the first protrusion 36 and the second protrusion 37. The cap 3 may not have the first protrusion 36 and the second protrusion 37 at all.

[0100] The shape of the hemostatic valve 4 is not limited to the above embodiment. For example, the hemostatic valve 4 may have only a circular plate-shaped base 40, and the protrusions 4A and 4B may not be provided.

[0101] <Other> End faces 36A and 37A are examples of the "upstream contact surfaces" of the present invention. Curved portions 37B and 37C, and bottom surface 39A are examples of the "upstream non-contact surfaces" of the present invention. The base end 20P and the contact surface 26A of the partial surface 26 are examples of the "downstream contact surfaces" of the present invention. The non-contact surface 26B of the partial surface 26 is an example of the "downstream non-contact surface" of the present invention. End face 370 and partial inner surface 32A are examples of the "lateral contact surfaces" of the present invention. Curved portion 37C and partial inner surfaces 27A and 32B are examples of the "lateral non-contact surfaces" of the present invention. Valve side surfaces 46S and 47S are examples of the "first partial valve side surfaces" of the present invention. Valve side surface 48S is an example of the "second partial valve side surface" of the present invention. Side portions 51S and 52S are examples of the "first partial side portions" of the present invention. Side portion 53S is an example of the "second partial side portion" of the present invention. The protruding portion 4A is an example of the "base end protruding portion" of the present invention. The protruding portion 4B is an example of the "tip protruding portion" of the present invention. The side portion 51S is an example of the "third part side portion" of the present invention. The side portion 53S is an example of the "fourth part side portion" of the present invention. The non-contact surface 26B is an example of the "inclined portion" of the present invention. The curved portion 37B is an example of the "boundary portion" of the present invention.

Claims

1. An introducer for inserting an insertor into the body, comprising: a housing having a through hole formed therein extending from a base end to a tip; and a hemostatic valve housed in a part of the through hole, wherein when the insertor is inserted into the introducer, the tip of the insertor moves in a first direction from the base end to the tip through the through hole, the first direction extending parallel to the central axis of the through hole; the hemostatic valve having a valve base end face and a valve tip face perpendicular to the first direction, and a valve side face perpendicular to a second direction which is radially outward with respect to the central axis, the valve base end face being close to the base end, the valve tip face being close to the tip, the downstream of the first direction indicating the positive direction of the first direction, the upstream of the first direction indicating the negative direction of the first direction, the downstream of the second direction indicating the positive direction of the second direction, and the upstream of the second direction indicating the negative direction of the second direction; and the housing is, An introducer having an upstream portion facing upstream in the first direction with respect to the valve base end face of the hemostatic valve, a downstream portion facing downstream in the first direction with respect to the valve tip face of the hemostatic valve, and a lateral portion facing downstream in the second direction with respect to the valve side surface of the hemostatic valve, wherein the upstream portion has an upstream contact surface that contacts the valve base end face and an upstream non-contact surface that does not contact the valve base end face, and the downstream portion has a downstream contact surface that contacts the valve tip face and a downstream non-contact surface that does not contact the valve tip face.

2. The introducer according to claim 1, characterized in that the side portion of the housing has a lateral contact surface that contacts the valve side surface of the hemostatic valve and a lateral non-contact surface that does not contact the valve side surface.

3. The introducer according to claim 2, wherein the valve side surface of the hemostatic valve has a first partial valve side surface and a second partial valve side surface located downstream in the first direction from the first partial valve side surface, the side portion of the housing has a first partial side portion facing downstream in the second direction from the first partial valve side surface of the hemostatic valve and a second partial side portion facing downstream in the second direction from the second partial valve side surface of the hemostatic valve, the first partial side portion has a lateral contact surface that contacts the first partial valve side surface of the hemostatic valve and a lateral non-contact surface that does not contact the first partial valve side surface of the hemostatic valve, and the second partial side portion does not have a lateral contact surface that contacts the second partial valve side surface of the hemostatic valve and has a lateral non-contact surface that does not contact the second partial valve side surface of the hemostatic valve.

4. The introducer according to claim 1, characterized in that the upstream non-contact surface of the upstream portion extends in the circumferential direction about the central axis.

5. The introducer according to claim 1, characterized in that the downstream non-contact surface of the downstream portion extends in the circumferential direction about the central axis.

6. The hemostatic valve has a proximal projection that protrudes toward the proximal end and a distal projection that protrudes toward the distal end, and the side portion of the housing has a third portion located downstream in the second direction from the proximal projection of the hemostatic valve and a fourth portion located downstream in the second direction from the distal projection of the hemostatic valve, and the radial distance between the upstream end of the fourth portion and the central axis is shorter than the radial distance between the upstream end of the third portion and the central axis.

7. The introducer according to claim 1, characterized in that the downstream non-contact surface of the downstream portion has an inclined portion that is inclined with respect to the first direction, and the radial distance between the inclined portion and the central axis gradually increases toward the first direction.

8. The introducer according to claim 1, characterized in that the boundary portion of the upstream non-contact surface of the upstream part with the upstream contact surface is curved.

9. The introducer according to claim 1, characterized in that the upstream portion has a first projection that protrudes toward the central axis and a second projection that protrudes toward the valve base end face.

10. The introducer according to claim 9, characterized in that the first projection is located upstream of the second projection in the first direction.

11. The introducer according to claim 1, characterized in that when the inserting body moves in the first direction, a part of the hemostatic valve deforms to move in a direction that approaches the downstream non-contact surface of the downstream portion, and when the inserting body moves in a direction opposite to the first direction, a part of the hemostatic valve deforms to move in a direction that approaches the upstream non-contact surface of the upstream portion.

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