JP7839488B2 - Subcutaneous implantable port - Google Patents

Description

This invention relates to a subcutaneous implantable port used in the medical field, which is implanted under the skin of a patient and used for injecting drug solutions or other substances into the body, and which can prevent the catheter from becoming dislodged.

Traditionally, when performing treatments that involve repeatedly injecting medications or other substances into the body over a long period, it has been considered to implant a subcutaneous port for medication injection in the patient to reduce the burden on the body caused by repeated punctures.

Such subcutaneous implantable ports for drug injection, like the subcutaneous implantable port shown in Japanese Patent Publication No. 2012-070986 (Patent Document 1), have a structure in which the opening of the housing is sealed with an elastic cap to form a lumen for drug storage. The drug injected into the lumen by a needle that penetrates the skin and punctures the elastic cap is then guided through a catheter via a connecting port, which forms a drug outflow channel on the outer circumference of the housing, into internal lumens such as blood vessels.

Incidentally, in conventional subcutaneous implantable ports, the catheter is fitted and connected to the connection port in an extracutaneous state. The catheter is, for example, cut to an appropriate length by a physician to match the patient's physique before being attached to the connection port. In some cases, the catheter may be removed from the connection port, re-adjusted to the correct length, and then re-attached. Therefore, it is desirable that the catheter be removable from the connection port without being glued or otherwise secured.

Japanese Patent Publication No. 2012-070986

Subcutaneous implantable ports are devices that are left in place for extended periods. As a result of prolonged placement, the tip or middle portion of the catheter may become fixed to the body. If the area where the subcutaneous implantable port is implanted is moved vigorously in this state, there is a risk that the catheter may become dislodged from the port.

The problem to be solved by this invention is to provide a novel subcutaneous implantable port with a structure that can stably maintain the connection state to the catheter's connection port.

The following describes preferred embodiments for understanding the present invention. These embodiments are illustrative and can be combined and adopted as appropriate. Furthermore, the multiple components described in each embodiment can be recognized and adopted as independently as possible, and can be combined with any component described in another embodiment as appropriate. Thus, the present invention is not limited to the embodiments described below, and various other embodiments can be realized.

A first aspect of the present invention is a subcutaneous implantable port having a housing that includes a lumen for storing a drug solution, which is sealed with an elastic lid, and a connection port that communicates with the lumen and is inserted into a catheter, wherein the housing is provided with a pair of locking projections on both sides in the circumferential direction, excluding portions that face each other in the vertical direction on either side of the connection port, and the pair of locking projections have a flexible portion formed at the base end portion in the protruding direction which is thinner than the tip end portion, and the housing has a sleeve-shaped connection cap that is fitted onto the catheter and radially sandwiches the connection end of the catheter between itself and the connection port, and the connection cap has a locking portion that can be locked into the pair of locking projections.
A second aspect of the present invention is a subcutaneous implantable port as described in the first aspect, wherein the deflection-allowing portion is provided while maintaining the height dimension of the locking projection.
A first aspect of the invention described in the original application is a subcutaneous implantable port having a housing that includes a lumen for storing a drug solution, which is sealed with an elastic lid, and a connecting port that communicates with the lumen and is inserted into a catheter, wherein the port has a sleeve-shaped connecting cap that is fitted onto the catheter and radially sandwiches the connecting end of the catheter between itself and the connecting port, and the connecting cap has a locking portion that can be locked to the housing.

According to the subcutaneous implantable port structure of this embodiment, the locking portion of the connecting cap is locked to the housing, thereby positioning the connecting cap in the withdrawal direction relative to the connecting port. This holds the catheter in a locked state, preventing it from coming loose by being sandwiched between the connecting cap and the connecting port, thus ensuring a stable connection to the port. Therefore, the risk of the catheter becoming dislodged from the subcutaneous implantable port due to unintentional pulling during long-term placement can be reduced.

A second aspect of the invention described in the original application is a subcutaneous implantable port as described in the first aspect of the invention described in the original application , wherein a pair of locking protrusions are provided on both sides of the housing in the circumferential direction, flanking the connection port, while a pair of guide surfaces are provided on the inner surfaces of both sides of the housing in the circumferential direction at the base end opening of the connection cap, each widening toward the base end, and the pair of locking protrusions are inserted into the connection cap along the pair of guide surfaces, and the pair of locking protrusions are locked in the withdrawal direction to a pair of locking portions provided behind the pair of guide surfaces.

According to the subcutaneous implantable port structure of this embodiment, by pushing the connection cap into the connection port, a pair of locking protrusions are guided by a pair of guide surfaces to the locking position with a pair of locking parts. Therefore, the connection cap can be easily positioned relative to the connection port, and the catheter can be easily prevented from coming loose by the connection cap.

A pair of guide surfaces are provided on the inner surface of the base end opening of the connection cap. This guides the connection cap to the correct position relative to the connection port when it is pushed into the port. Therefore, the connection cap can be easily and correctly attached, and the pair of locking protrusions and the pair of locking parts are effectively engaged.

A third aspect of the invention described in the original application is a subcutaneous implantable port as described in the second aspect of the invention described in the original application , wherein the locking projection is provided with a deflection-allowing portion located on the base end side and having a reduced cross-sectional area.

According to the subcutaneous implantable port structure of this embodiment, when attaching the connection cap, the pair of locking protrusions flex and deform so that they approach each other within the allowable flexure area. This reduces the force required to engage the pair of locking protrusions with the pair of locking parts when pushing the connection cap into the connection port, making it easier to attach the connection cap.

A fourth aspect of the invention of the original application is a subcutaneous implantable port as described in the second or third aspect of the invention of the original application , wherein the housing comprises a base housing member that constitutes the bottom wall of the lumen and an outer housing member that clamps the outer peripheral portion of the elastic cover between itself and the base housing member, the connection port is provided on one of the base housing member and the outer housing member, and the pair of locking protrusions is provided on the other of the base housing member and the outer housing member.

According to the subcutaneous embedded port structure of this embodiment, the connection port and a pair of locking protrusions are provided on one of the base housing member and the outer housing member that constitute the housing. Therefore, the design freedom for the shape of the connection port and the pair of locking protrusions is increased, and the manufacturing of the housing becomes easier.

A fifth aspect of the invention in the original application is a subcutaneous implantable port described in any one of the first to fourth aspects of the invention in the original application , wherein the connecting cap has a flat outer surface shape having two orthogonal axes of different lengths.

According to the subcutaneous implantable port structure of this embodiment, the connection cap has a flattened outer surface, making it easy to grasp and hold the flattened portion of the connection cap along its short axis. Therefore, when pushing the connection cap into the connection port, it is easier to apply force to the connection cap, making the installation process simpler.

A sixth aspect of the invention of the original application is a subcutaneous implantable port described in any one of the first to fifth aspects of the invention of the original application , wherein the base end of the connecting cap has a larger diameter than the tip end, and a stepped portion is provided on the outer circumferential surface of the connecting cap.

According to the subcutaneous implantable port structure of this embodiment, pressing the stepped portion makes it easier to push and attach the connection cap to the connection port.

A seventh aspect of the invention of the original application is a subcutaneous implantable port described in any one of the first to sixth aspects of the invention of the original application , wherein the connecting cap is formed of a material that is harder than the proximal portion that extends beyond the connecting port and is fitted onto the catheter, and which radially sandwiches the connecting end of the catheter between itself and the connecting port.

According to the subcutaneous implantable port structure of this embodiment, the catheter's connecting end is radially sandwiched between the relatively rigid proximal portion of the connecting cap and the connecting port, effectively preventing the catheter from detaching from the port. Furthermore, the tip portion extending beyond the connecting port is made of a relatively soft material, preventing kinking of the catheter protruding from the connecting cap. Therefore, the connecting cap according to this embodiment achieves both the shape stability required for the proximal portion and the flexibility required for the tip portion.

An eighth aspect of the invention in the original application is a subcutaneous implantable port described in the seventh aspect of the invention in the original application , wherein the base portion and the tip portion, which are made of different materials, are fixed to each other by a mechanically engaged anchor portion.

According to the subcutaneous implantable port structure of this embodiment, separation of the proximal and distal portions is more advantageously prevented by mechanical engagement at the anchor portion.

According to the present invention, in a subcutaneous implantable port, the connection state to the catheter's connection port is stably maintained.

A perspective view showing a subcutaneous implantable port as the first embodiment of the present invention. Front view of the subcutaneous implantable port shown in Figure 1. Plan view of the subcutaneous implantable port shown in Figure 1. Bottom view of the subcutaneous implantable port shown in Figure 1. Right side view of the subcutaneous implantable port shown in Figure 1. Figure 2, VI-VI cross-sectional view Figure 2, section view between VII and VII Perspective view of the port body constituting the subcutaneous implantable port shown in Figure 1. Cross-sectional view of the port body shown in Figure 8. Another cross-sectional view of the port body shown in Figure 8. Figure 8 shows an exploded perspective view of the housing that constitutes the port body. Perspective view of the connection cap constituting the subcutaneous implantable port shown in Figure 1. Cross-sectional view of the connecting cap shown in Figure 12. Another cross-sectional view of the connection cap shown in Figure 12.

The embodiments of the present invention will be described below with reference to the drawings.

Figures 1-7 show a subcutaneous implantable port 10 as a first embodiment of the present invention. The subcutaneous implantable port 10 has a structure in which a connection cap 14 is attached to a port body 12. In the following description, "up and down direction" generally refers to the up and down direction in Figure 2.

As shown in Figures 8-10, the port body 12 has a structure in which an elastic cover 18 and a port member 20 are attached to a housing 16. The opening of the recess 22 in the housing 16 is closed by the elastic cover 18, thereby forming a lumen 24 for storing the drug solution, with the housing 16 and the elastic cover 18 forming the wall. The port member 20 is in communication with this lumen 24.

The housing 16 is made of a hard synthetic resin or metal and, as shown in Figure 11, is a divided structure having a base housing member 26 and an outer housing member 28. The base housing member 26 is a substantially bottomed cylindrical shape with a peripheral wall portion 30 and a bottom wall portion 32, and a recess 22 opening upwards is formed in the central portion. The opening of the recess 22 is provided by an annular step portion 34, formed by the inner circumferential corner of the peripheral wall portion 30 being notched and widened.

A port portion 36 is provided in a part of the circumferential direction of the peripheral wall portion 30 of the base housing member 26. The port portion 36 is approximately rectangular in shape and is provided by partially thickening the peripheral wall portion 30 outward, protruding from the outer circumferential surface of the peripheral wall portion 30. A communication hole 38 is formed in the peripheral wall portion 30, passing through the port portion 36.

A flange-shaped annular projection 40 is formed at the lower end of the base housing member 26, projecting outward. On both sides of the annular projection 40, flanking the port portion 36, a pair of fitting plate portions 42, 42 are formed, projecting more significantly outward.

The outer housing member 28 is substantially cylindrical in shape, extending in the vertical direction. The upper part of the outer housing member 28 has a tapered shape, with the internal and external dimensions gradually increasing perpendicular to the axis towards the bottom. The lower part of the outer housing member 28 has an internal circumferential surface with a substantially constant internal dimension along its entire circumference, and a flared external circumferential surface with an external dimension gradually increasing towards the bottom.

The outer housing member 28 has a vertical wall portion 44 with a flat outer peripheral surface that extends vertically in a portion of its circumferential direction. The vertical wall portion 44 is provided in the housing 16 at a position corresponding to the port portion 36 of the base housing member 26, and is equipped with an opening window 46 that exposes the port portion 36 to the outer periphery.

The outer housing member 28 is provided with a pair of locking projections 48, 48. The pair of locking projections 48, 48 are roughly rectangular block-shaped. The pair of locking projections 48, 48 protrude from the vertical wall portion 44 in a direction approximately perpendicular to the vertical wall portion 44 on both sides in the width direction of the opening window 46.

The pair of locking projections 48, 48 are positioned opposite each other and spaced apart in the width direction of the vertical wall portion 44, which is the circumferential direction of the outer housing member 28. The distance between the opposing locking projections 48, 48 is smaller than the opening width dimension of the opening window 46, and the pair of locking projections 48, 48 protrude from both sides in the width direction over the opening on the outer circumference of the opening window 46, partially covering the opening window 46. Because the pair of locking projections 48, 48 protrude over the opening window 46, the base end of each locking projection 48 connected to the vertical wall portion 44 has a smaller width dimension than the other parts of the locking projection 48. As a result, the base end of the locking projection 48 is provided with a deflection allowance portion 50 in which the cross-sectional area in the direction perpendicular to the protruding direction of the locking projection 48 is partially reduced.

Each of the pair of locking projections 48, 48 is provided with an engaging projection 52 that protrudes outward in the width direction at its tip. The engaging projection 52 is a ridge with a substantially semicircular cross-section extending vertically, and is continuously provided across the entire vertical length of the locking projection 48.

An annular retaining portion 54 is provided at the opening at the upper end of the outer housing member 28, projecting inward toward the inner circumference. A locking claw 56, with a tapered cross-section, projecting downward toward the inner circumference, is formed along the entire circumference of the annular retaining portion 54.

As shown in Figure 4, a fitting recess 58 corresponding to the fitting plate portions 42, 42 of the base housing member 26 is formed on the bottom surface of the outer housing member 28. A service hole 60, extending vertically, is formed in the portion of the outer housing member 28 adjacent to the outer circumference of the fitting recess 58. The service hole 60 can be used as appropriate, for example, for positioning during manufacturing or installation, or for fixing the outer housing member 28 to the base housing member 26 or port member 20 by providing a fitting pin to the base housing member 26 or port member 20.

As shown in Figures 9 and 10, the housing 16 is constructed by placing the outer housing member 28 over the base housing member 26 from above and fixing it in an externally fitted state to the peripheral wall portion 30 of the base housing member 26. The port portion 36 of the base housing member 26 is inserted into the opening window 46 of the outer housing member 28. The fitting plate portions 42, 42 of the base housing member 26 are inserted into the fitting recesses 58, 58 of the outer housing member 28. In this way, the base housing member 26 and the outer housing member 28 are positioned in the circumferential direction. The base housing member 26 and the outer housing member 28 are fixed to each other by means of ultrasonic welding or the like, if necessary. Ribs for welding may be provided on the upper surface or the like that are superimposed on the inner circumferential surface of the opening window 46, which is inserted into the opening window 46 of the base housing member 26. Furthermore, the formation location of the welding ribs is not limited to the port portion 36. Welding ribs can be appropriately provided on the overlapping surface of the base housing member 26 and the outer housing member 28. For example, the welding ribs can be provided on the outer housing member 28 side.

The port portion 36 of the base housing member 26 is inserted into the opening window 46 of the outer housing member 28, and the pair of fitting plate portions 42, 42 of the base housing member 26 are fitted into the pair of fitting recesses 58, 58 of the outer housing member 28.

An elastic cover 18 is attached to the housing 16. The elastic cover 18 is made of an elastic material such as elastomer or rubber. The elastic cover 18 has a roughly disc-like shape with its central axis oriented in the vertical direction.

The elastic cover 18 is inserted into the inner circumference of the outer housing member 28, and its outer circumference is sandwiched between the peripheral wall 30 of the base housing member 26 and the annular retaining portion 54 of the outer housing member 28, compressing the outer circumference vertically. As a result, the elastic cover 18 is attached to the housing 16 with its outer circumference fluidly and tightly supported by the housing 16.

As shown in Figure 10, a contrast-enhanced ring 62 made of titanium, stainless steel, aluminum, or an alloy thereof is fitted onto the upper outer circumference of the peripheral wall portion 30 of the base housing member 26. By heating the outer surface of the contrast-enhanced ring 62 with laser light and applying markings through oxidation, for example, the manufacturer's name, manufacturing date, lot number, etc., can be displayed. In this case, the outer housing member 28 covering the outer surface of the contrast-enhanced ring 62 is made of a colorless or colored transparent material that transmits visible light, making the markings on the contrast-enhanced ring 62 visible from the outside. However, the contrast-enhanced ring 62 is not essential; for example, markings may be applied directly to the housing 16 without the contrast-enhanced ring 62.

The elastic lid 18 is assembled to the housing 16, thereby fluidly defining a lumen 24 for storing the chemical solution, with the elastic lid 18 and the housing 16 forming the walls, relative to the external space. The lumen 24 is formed when the opening of the recess 22 in the base housing member 26 is fluidly sealed by the elastic lid 18.

The lumen 24 is open to the outside through a communication hole 38 provided in the port portion 36 of the base housing member 26. A port member 20 is attached to the communication hole 38 of the base housing member 26. As shown in Figures 9 and 10, the port member 20 is a substantially cylindrical tube with a central hole 64. The port member 20 comprises a base cylindrical portion 66 and a tip cylindrical portion 68, with the outer diameter of the base cylindrical portion 66 being larger than that of the tip cylindrical portion 68. The base cylindrical portion 66 of the port member 20 is provided with a flange-shaped fitting projection 70 protruding from its outer circumferential surface. The outer circumferential surface of the tip cylindrical portion 68 of the port member 20 has multiple return-shaped protrusions 72 arranged along its length, increasing in diameter towards the base end side (upper side in Figures 6 and 9).

The port member 20 is attached to the base housing member 26 by inserting its base cylindrical portion 66 into the communication hole 38 of the base housing member 26. This allows the central hole 64 of the port member 20 to communicate with the lumen 24 for storing the drug solution through the communication hole 38 of the base housing member 26. Furthermore, the tip cylindrical portion 68 of the port member 20 protrudes from the communication hole 38 of the base housing member 26, and the tip cylindrical portion 68 of the port member 20 constitutes the connection port in this embodiment.

Furthermore, the outer housing member 28 is assembled from above to the base housing member 26, which has the port member 20 attached. The base housing member 26 and the outer housing member 28 are assembled vertically by inserting the tip cylindrical portion 68 of the port member 20 into the space between the pair of locking protrusions 48, 48.

When the base housing member 26 and the outer housing member 28 are assembled, the base end cylindrical portion 66 (fitting projection 70) of the port member 20 abuts against the pair of locking projections 48, 48 of the outer housing member 28 in the direction of withdrawal of the port member 20 from the base housing member 26, and is locked in place (see Figure 9). In this way, by assembling the base housing member 26 and the outer housing member 28, the base end cylindrical portion 66 of the port member 20 is sandwiched between the base housing member 26 and the outer housing member 28, preventing the port member 20 from falling out of the housing 16. In short, in this embodiment, the structure that prevents the port member 20 from coming out of the housing 16 is constructed using the pair of locking projections 48, 48 provided on the housing 16.

Furthermore, the outer housing member 28 is provided with an area for accommodating the port portion 36 of the base housing member 26. This allows the width dimension a (see Figure 6) at the base end of the pair of locking projections 48, 48 to be smaller than the width dimension of other parts, thereby forming each deflection-allowing portion 50. In this way, the deflection-allowing portion 50 in this embodiment is provided by reducing the width dimension while maintaining the height dimension of the locking projection 48. Although the port portion 36 of the base housing member 26 is superimposed on the inner portion in the width direction of the pair of locking projections 48, 48 from the base end side, a gap is provided between the port portion 36 and the pair of locking projections 48, 48, and this gap allows deformation of the deflection-allowing portion 50. However, this gap is not necessarily required. For example, an elastic body may be interposed between the port portion 36 and the pair of locking protrusions 48, 48, allowing deformation of the deflection-allowing portion 50 through the deformation of the elastic body. Alternatively, slight deformation of the port portion 36 and the pair of locking protrusions 48, 48 could also allow deformation of the deflection-allowing portion 50.

The pair of locking projections 48, 48 on the outer housing member 28 are positioned spaced apart on both sides in the width direction relative to the tip cylindrical portion 68 of the port member 20 that protrudes from the base housing member 26. In other words, when the base housing member 26 and the outer housing member 28 are assembled, the tip cylindrical portion 68 of the port member 20 is positioned between the opposing locking projections 48, 48.

The tip cylindrical portion 68 of the port member 20 protrudes beyond the tips of the pair of locking projections 48, 48 of the outer housing member 28, passing between their opposing positions. In particular, the portion of the tip cylindrical portion 68 of the port member 20 where the protrusion 72 is provided is located further outward than the pair of locking projections 48, 48.

As shown in Figures 6 and 7, a catheter 74 is attached to the port member 20. The catheter 74 is a flexible tube, and the tip tubular portion 68 of the port member 20 is inserted and connected to the connecting end of the catheter 74. This connects the catheter 74 to the lumen 24 of the subcutaneous implantable port 10 for drug solution storage via the port member 20. Since the tip tubular portion 68 of the port member 20 has multiple protrusions 72 on its outer surface, the catheter 74, which is fitted in an externally inserted state, is difficult to dislodge. One end of the catheter 74 is attached to the port member 20 and connected to the subcutaneous implantable port 10, while the other end is connected to an internal lumen such as a blood vessel.

A connection cap 14 is attached to the connection portion between the port member 20 and the catheter 74. As shown in Figures 12-14, the connection cap 14 is sleeve-shaped (tubular) overall and comprises a proximal end portion 76 and a distal end portion 78 made of different materials.

The base portion 76 is made of a harder material than the tip portion 78, and is formed of, for example, synthetic resin or metal. The base portion 76 integrally includes a bottomed cylindrical connecting portion 80 and a connecting portion 82 that protrudes from the connecting portion 80 toward the tip side (the lower side in Figures 6 and 13). The base portion 76 may be formed entirely of a single material, or it may be formed by a combination of, for example, synthetic resin and metal.

As shown in Figure 12, the connecting portion 80 has a width dimension W in the circumferential direction of the housing 16 that is larger than the height dimension H in the height direction of the housing 16, and has a flattened outer surface shape with two orthogonal axes (long axis and short axis) of different lengths. In this embodiment, the connecting portion 80 has an oval cross-section. The base end opening 83 of the connecting portion 80 has a roughly rectangular cross-section, and its width dimension w is larger than its height dimension h.

The inner circumferential surface of the connecting portion 80 is provided with a pair of protrusions 84, 84 projecting from both sides in the width direction, which is the longitudinal axis direction of the connecting portion 80. The pair of protrusions 84, 84 are positioned facing each other in the width direction, and the width dimension of the inner circumferential surface of the connecting portion 80 decreases in the portion where the pair of protrusions 84, 84 are provided. The protruding tip surfaces of the pair of protrusions 84, 84 each widen toward the base end side of the base end opening 83 of the connecting portion 80; in other words, they are guide surfaces 86 that incline inward in the width direction from the base end side toward the back of the base end opening 83. As a result, in the portion where the pair of protrusions 84, 84 are provided, the width dimension of the inner circumferential surface of the connecting portion 80 gradually increases toward the opening.

On the peripheral wall of the connecting portion 80, groove-shaped portions 88 extending vertically are provided behind the pair of protrusions 84, 84. The stepped surfaces, which are both the inner surfaces of the groove-shaped portions 88, 88 and the inner sides of the pair of protrusions 84, 84, constitute the pair of locking portions 90, 90 in this embodiment. Thus, the pair of locking portions 90, 90 are provided on the base end portion 76 of the connecting cap 14.

As shown in Figures 13 and 14, the connecting portion 82 is roughly rectangular in shape, with a pair of anchor holes 92, 92 penetrating vertically formed on both sides in the width direction (left-right direction in Figure 13).

A first insertion hole 94 with a circular cross-section is formed in the central part of the base end portion 76 in the width direction, extending in directions perpendicular to the vertical and width directions. In this embodiment, the first insertion hole 94 has a tapered shape at the base end, widening in the left-right direction in Figure 13 toward the base end. However, the base end of the first insertion hole 94 may have substantially the same cross-sectional shape as the other portions.

The tip portion 78 is made of a softer material than the base portion 76, and is formed of an elastic material such as synthetic resin elastomer or rubber. As shown in Figures 12-14, the outer shape of the tip portion 78 smoothly changes from a flattened oval shape to a circular shape from the base to the tip. A connecting recess 96 is formed on the base side of the tip portion 78, corresponding in shape to the connecting portion 82 of the base portion 76. A pair of insertion portions 98, 98, corresponding to the pair of anchor holes 92, 92 of the connecting portion 82, extend vertically from the connecting recess 96 and are continuous with both the upper and lower inner surfaces of the connecting recess 96. A second insertion hole 100 is formed in the central portion of the tip portion 78. The second insertion hole 100 is a circular hole corresponding to the first insertion hole 94 and extends through the tip portion 78 from the base to the tip.

The base portion 76 and the tip portion 78 are arranged in series and connected to each other. The connecting portion 82 of the base portion 76 is fitted into the connecting recess 96 of the tip portion 78 and fixed in place. Furthermore, the insertion portions 98, 98 of the tip portion 78 are provided in a state where they are inserted through the anchor holes 92, 92 of the base portion 76, forming a pair of anchor portions 102, 102 that prevent separation of the base portion 76 and the tip portion 78. While the base portion 76 and the tip portion 78 may be fixed to each other by means of welding or other means after molding, in this embodiment, the base portion 76 and the tip portion 78 are molded in a state where they are fixed to each other by insert molding, two-color molding, or stepwise molding. As a result, the insertion portions 98, 98 of the tip portion 78 are formed in a state where they are inserted through the anchor holes 92, 92 of the base portion 76.

As shown in Figures 1-7, the connecting cap 14 is fitted over the tip cylindrical portion 68 of the port member 20 protruding from the housing 16. Then, as shown in Figures 6 and 7, the connecting cap 14 is fitted over the port member 20 to which the catheter 74 is attached in its external state, preventing the catheter 74 from coming loose from the port member 20. In other words, the end of the catheter 74 that connects to the port member 20 is sandwiched between the outer circumferential surface of the port member 20 and the rigid proximal end portion 76 of the connecting cap 14, thereby firmly attaching the catheter 74 to the port member 20.

The catheter 74 is sandwiched radially between the port member 20 and the connecting cap 14, for example, as follows. That is, the catheter 74 is first externally fitted onto the port member 20 so that it covers the position from the tip of the tip cylindrical portion 68 to the protrusion 72 or beyond the protrusion 72. Preferably, the catheter 74 is inserted to the back side (proximal end side) of the tip surfaces of the locking projections 48, 48 of the housing 16 and inserted between the locking projections 48, 48. By fitting the catheter 74 not only into the connecting cap 14 but also into the space between the opposing locking projections 48, 48 provided on the housing 16, the connection between the catheter 74 and the port member 20 can be achieved more reliably and stably. In addition, because the catheter 74 is sandwiched between the port member 20 and the locking projections 48, 48, it is less likely that the catheter 74 will come off the port member 20 before the connecting cap 14 is attached to the housing 16. Next, when the connecting cap 14 is attached to the port member 20 on which the catheter 74 is enclosed, the catheter 74, sandwiched between the tip tube portion 68 and the port member 20, moves toward the proximal end of the tip tube portion 68 together with the connecting cap 14, and is externally inserted further toward the proximal end, for example, until it is inserted between the pair of locking protrusions 48, 48. Preferably, the outer diameter of the catheter 74 fitted over the tip tube portion 68 of the port member 20 is made larger than the inner diameter of the connecting cap 14, thereby allowing the catheter 74 to move toward the proximal end efficiently together with the connecting cap 14.

As shown in Figure 6, the connecting cap 14 is connected to a pair of locking protrusions 48, 48 of the outer housing member 28. That is, when attaching the connecting cap 14 to the outer housing member 28, the tip cylindrical portion 68 of the port member 20 and the catheter 74 are inserted through the first insertion hole 94 and the second insertion hole 100 of the connecting cap 14 and brought close to the outer housing member 28. Then, the pair of locking protrusions 48, 48 of the outer housing member 28 are inserted into the inner circumference of the base end portion 76 of the connecting cap 14 through the pair of guide surfaces 86, 86. The pair of engaging projections 52, 52 provided on the pair of locking protrusions 48, 48 slide in contact with the pair of guide surfaces 86, 86 of the connecting cap 14, overcoming the pair of protrusions 84, 84 and entering the pair of groove-shaped portions 88, 88. As described above, the pair of guide surfaces 86, 86 facilitate the insertion of the pair of engaging protrusions 52, 52 into the pair of groove-like portions 88, 88. When the pair of engaging protrusions 52, 52 enter the pair of groove-like portions 88, 88, they overlap with the pair of protrusions 84, 84 in the axial direction by a predetermined width x, thereby locking the pair of engaging protrusions 52, 52 into the pair of locking portions 90, 90 of the connecting cap 14 in the withdrawal direction. As a result, the connecting cap 14 is connected to the outer housing member 28 in a state where it is prevented from coming loose. In short, the connecting cap 14 is connected to the pair of locking protrusions 48, 48 of the outer housing member 28 by a snap-fit mechanism.

In this way, by bringing the connection cap 14 close to the outer housing member 28 and fitting the pair of locking protrusions 48, 48 into the connection cap 14, the connection cap 14 can be easily attached to the connection portion between the port member 20 and the catheter 74. Furthermore, the tactile feedback when the pair of engaging protrusions 52, 52 overcome the pair of projections 84, 84 and enter the pair of groove-shaped portions 88, 88 allows the user to confirm that the connection cap 14 and the outer housing member 28 are securely fixed.

The connecting cap 14 has a flattened base end, and in particular, the hard base end portion 76 has a flattened shape, making it easier to apply force to the connecting cap 14 when pushing the pair of locking protrusions 48, 48 into the connecting cap 14. Moreover, in this embodiment, the base end of the tip end portion 78 has a flat outer surface shape, and the tip end of the tip end portion 78 has a circular outer surface, with the base end having a larger diameter in the longitudinal direction than the tip end. As a result, gentle stepped portions 104 are formed on both sides in the longitudinal direction of the outer circumferential surface of the intermediate portion of the tip end portion 78. By applying force to the stepped portions 104, 104 with the user's fingers, it becomes easier to push the connecting cap 14 toward the outer housing member 28. The force applied to the stepped portions 104 is transmitted to the tip surface of the hard base end portion 76 via the soft tip end portion 78. The stepped portion 104 only needs to extend in a direction that intersects the axial direction of the connecting cap 14; for example, it can be formed by a plane that is approximately perpendicular to the axial direction of the connecting cap 14.

Furthermore, a pair of protrusions 84, 84 are provided on both sides of the connecting cap 14 in the longitudinal direction (width direction). Therefore, by applying a pushing force to both sides of the connecting cap 14 in the width direction, the force can be directly applied to the area where resistance acts when the pair of engaging protrusions 52, 52 overcomes the pair of protrusions 84, 84.

Furthermore, the pair of locking portions 90, 90 on the connecting cap 14 and the pair of locking protrusions 48, 48 on the outer housing member 28 may be in constant contact and locked. Alternatively, for example, as shown in Figure 6, the pair of locking portions 90, 90 and the pair of locking protrusions 48, 48 may be separated from each other, and the pair of locking portions 90, 90 and the pair of locking protrusions 48, 48 may come into contact and lock when the connecting cap 14 is displaced in a direction that allows it to detach from the outer housing member 28.

The pair of locking projections 48, 48 are positioned spaced apart in the width direction relative to the tip cylindrical portion 68 of the port member 20. Therefore, when the pair of engaging projections 52, 52 overcome the pair of protrusions 84, 84, the pair of locking projections 48, 48 are allowed to undergo elastic bending deformation in a direction approaching the tip cylindrical portion 68 of the port member 20. In particular, each of the pair of locking projections 48, 48 is provided with a bending allowance portion 50 with a reduced cross-sectional area, thereby advantageously allowing bending deformation of the pair of locking projections 48, 48 at each bending allowance portion 50.

The connection cap 14 is fitted into its predetermined position when the pair of locking protrusions 48, 48 are inserted into the connection cap 14 until the bottom inner surface of the connection portion 80 of the connection cap 14 contacts the tip surfaces of the pair of locking protrusions 48, 48. As a result, the tip cylindrical portion 68 of the port member 20 is housed within the connection cap 14, and the catheter 74, which is externally fitted onto the tip cylindrical portion 68 of the port member 20, is compressed radially between the port member 20 and the connection cap 14. Consequently, the catheter 74 is prevented from coming loose by the fitting of the connection cap 14. Since the tip portion 78 of the connection cap 14 is made of a soft material, the inner circumferential surface of the tip portion 78 expands in diameter along the outer circumferential surface of the catheter 74 fitted onto the tip cylindrical portion 68. It is desirable that the inner circumferential surface of the connection cap 14 has a smooth shape without protrusions, thereby preventing damage to the catheter 74 inserted into the connection cap 14.

Furthermore, when a tensile force is applied to the catheter 74 in the withdrawal direction, the pair of locking portions 90, 90 of the connecting cap 14 and the pair of engaging projections 52, 52 of the pair of locking protrusions 48, 48 of the outer housing member 28 are locked together. This prevents the connecting cap 14 from detaching from the pair of locking protrusions 48, 48. Therefore, the connecting cap 14 does not detach from the port member 20 together with the catheter 74, and the connection between the catheter 74 and the port member 20 is stably maintained by the connecting cap 14.

The tip portion 78 of the connecting cap 14, which extends beyond the tip cylindrical portion 68 of the port member 20 and is externally fitted onto the catheter 74, is made of a softer material than the proximal portion 76, which has a pair of guide surfaces 86, 86 and a pair of locking portions 90, 90. Therefore, kinking of the catheter 74 is less likely to occur at the tip of the connecting cap 14. Furthermore, the soft tip portion 78 has a cross-sectional shape that changes from circular to oval, with the proximal end being flattened, covering the tip of the hard proximal portion 76. Therefore, when fitting the connecting cap 14 onto the pair of locking protrusions 48, 48, force can be applied to the hard proximal portion 76 via the flexible tip portion 78, making it easier to apply force to the connecting cap 14.

The rigid proximal portion 76 and the flexible tip portion 78 of the connecting cap 14 are fixed to each other by a pair of anchor portions 102, 102, through which a pair of insertion portions 98, 98 of the tip portion 78 are inserted into a pair of anchor holes 92, 92 of the proximal portion 76. This mechanically connects the proximal portion 76 and the tip portion 78, which are made of different materials, making them inseparable. This prevents damage such as disassembly of the connecting cap 14 due to external forces such as tensile force exerted by the catheter 74.

The overlap x in the width direction between the pair of engaging projections 52, 52 of the pair of locking projections 48, 48 and the pair of locking parts 90, 90 is not particularly limited, but is preferably about 0.1 mm to 0.25 mm. This allows for effective prevention of the connection cap 14 coming off the pair of locking projections 48, 48 while suppressing the force required to attach the connection cap 14 to the pair of locking projections 48, 48.

While embodiments of the present invention have been described in detail above, the present invention is not limited by its specific description. For example, the connecting cap may be formed entirely from a single material, or it may be composed of three or more parts made of different materials.

In the above embodiment, the connection cap 14 had a flattened outer surface at its base end. However, the entire cap may have a non-flattened shape, such as a cylindrical shape, or it may have a flattened shape, such as an elliptical cylinder, or the tip or intermediate portion may have a flattened shape. Furthermore, in a connection cap 14 where at least a portion has a flattened outer surface, the long axis direction may be the height direction of the subcutaneous implantable port 10.

In the above embodiment, the connection cap 14 had a connection portion 80 at the base end portion 76 in which a pair of locking protrusions 48, 48 were inserted and a hole in which the tip cylindrical portion 68 of the port member 20 was inserted, both of which were connected without a partition. However, for example, a partition could be provided on the inner circumference of the connection portion 80, or the connection portion 80 could be made into a double cylindrical shape, so that the hole in which the pair of locking protrusions 48, 48 were inserted and the hole in which the tip cylindrical portion 68 of the port member 20 and the catheter 74 were inserted could be independent of each other.

The connecting cap 14 is preferably removable from the outer housing member 28, for example, by pulling it strongly in the removal direction. The connecting cap 14 can also be fixed to the outer housing member 28 in a way that prevents removal.

The connection cap 14 and housing 16 can be attached using a screw thread and screw groove locking mechanism, i.e., a screw-fitting structure, instead of the mounting structure described above, which relies on the locking of the protrusions 84, 84 (locking portions 90, 90) of the connection cap 14 and the engaging projections 52, 52 of the housing 16.

However, the connecting cap 14 and the housing 16 are preferably connected by locking with protrusions as in the above embodiment. That is, if the connecting cap 14 and the housing 16 are connected by a screw structure (screw-in), it is difficult to sense the fixed end due to the tightening operation, so variations or insufficient tightening are likely to occur, and it is difficult to stably achieve a reliable connection state. In contrast, with a recessed locking structure as in the embodiment, it is possible to stably obtain the desired fixed state. Also, the fixing part by screw requires the formation of screw threads or screw grooves around the entire circumference, and since the cross-section becomes a relatively large circle, it becomes difficult to realize a connection structure between the connecting cap and housing where the height dimension is small compared to the width dimension, as in the embodiment, for example. Therefore, the connecting cap will protrude vertically from the housing, making the overall size easily larger, and gaps are likely to occur due to the step difference between the two members, which may impair the fluid-tight connection performance of the catheter. In particular, in the above embodiment, a flattened connecting cap that is larger in the width direction (circumferential direction) than in the height direction is adopted, and a locking structure is provided on both sides in the width direction. This allows for a large distance from the center of the connecting member to the locking structure while keeping the height size small. Therefore, it is possible to minimize the rattle of the connecting cap relative to the housing caused by the rattle of the interlocking protrusions and recesses in the connected state.

The guide surface 86 is not necessarily limited to being composed of substantially the entire tip surface of the protruding portion 84. For example, a chamfer or rounded edge may be provided at the base end corner of the protruding portion 84 in the base end opening 83 of the connecting portion 80.

The pair of locking protrusions 48, 48 may be provided on the base housing member 26. Furthermore, the housing 16 is not limited to a divided structure having an outer housing member 28 and a base housing member 26; it may be a single structure or composed of three or more divided parts.

The deflection-allowing portion provided on the pair of locking projections does not necessarily have to be located at the base ends of the pair of locking projections; for example, it may be provided in the intermediate portion of the pair of locking projections.

In the above embodiment, a pair of engaging projections 52, 52 provided on the sides of a pair of locking protrusions 48, 48 entered into a pair of groove-like portions 88, 88 provided behind a pair of guide surfaces 86, 86, and were locked into a pair of locking portions 90, 90. However, for example, locking holes may be provided on the sides of the pair of locking protrusions, and locking projections may be provided behind the pair of guide surfaces that are inserted into these locking holes and locked in the withdrawal direction.

The catheter 74, which is attached to the tip cylindrical portion 68 of the port member 20 in an externally fitted state, may have its proximal end inserted between the pair of locking projections 48, 48, with its end face in contact with the proximal cylindrical portion 66 of the port member 20. However, the proximal end of the catheter 74 may be positioned midway between the protruding directions of the pair of locking projections 48, 48, or it may be positioned without reaching between the pair of locking projections 48, 48.

The catheter 74 may be fixed to the port member 20 by means of adhesive or welding. The catheter 74 can also be fixed to the port member 20 by pressing it against the outer surface of the port member 20 using the connecting cap 14.

10 Subcutaneous implantable port 12 Port body 14 Connection cap 16 Housing 18 Elastic cover 20 Port member 22 Recess 24 Lumen 26 Base housing member 28 Outer housing member 30 Peripheral wall 32 Bottom wall 34 Annular step 36 Port portion 38 Communication hole 40 Annular projection 42 Fitting plate 44 Vertical wall 46 Opening window 48 Locking projection 50 Flexible portion 52 Engaging projection 54 Annular retaining portion 56 Locking claw 58 Fitting recess 60 Service hole 62 Contrast ring 64 Center hole 66 Base end cylinder 68 Tip cylinder (connection port)
70 Fitting projection 72 Protrusion 74 Catheter 76 Proximal end portion 78 Tip portion 80 Connecting portion 82 Linking portion 83 Proximal end opening 84 Projection portion 86 Guide surface 88 Groove-shaped portion 90 Locking portion 92 Anchor hole 94 First insertion hole 96 Connecting recess 98 Insertion portion 100 Second insertion hole 102 Anchor portion 104 Stepped portion

Claims (1)

A subcutaneous implantable port having a housing that includes a lumen for storing a drug solution, which is sealed with an elastic lid, and a connection port that communicates with the lumen and is inserted into a catheter,
The housing is provided with a pair of locking protrusions on both sides in the circumferential direction, excluding the portions that face each other vertically across the connection port.
The pair of locking protrusions have a flexible portion formed at the base end in the protruding direction, which is thinner than the tip end.
The catheter has a sleeve-shaped connecting cap that is externally fitted to the catheter and radially sandwiches the connecting end of the catheter between itself and the connecting port.
The connecting cap has the pair of locking protrusions and a lockable locking portion ,
The housing is provided with an opening window from which the connection port protrudes.
The pair of locking protrusions are positioned on the circumferential edges of the opening window and are formed to protrude outward from the housing.
Each of the protruding base portions of the locking projections is a subcutaneously embedded port that extends inward toward the opening window in the opposite direction .