Implantable chamber and associated kit

Abstract

The chamber comprises a peripheral shell (52) having a peripheral lip (78). It includes a tip (79) extending between the peripheral lip (78) and a lower surface (72) of the peripheral shell (52), projecting from the peripheral lip (78), to a free end (81). In a median vertical plane containing the free end (81), the ratio between: - the vertical radius of curvature (RV) of the tip (79), taken between the peripheral lip (78) and the free end (81); and - the distance (DP) separating the projection (P1) of the peripheral lip (78) onto the lower surface (72) closest to the free end (81) and the projection (P2) of the free end (81) onto a plane defined by the lower surface (72) is between 2.0 and 4.0.

Description

[0001] The present invention relates to an implantable chamber, suitable for implantation under the skin of a patient, comprising: a hollow base body delimiting an internal volume for the circulation of the liquid, the internal volume opening through a main opening; a septum closing the main opening, the septum being intended to be punctured by a needle; a conduit for the evacuation of liquid from the internal volume projecting away from the base body, the base body comprising an inner container and an outer peripheral shell assembled on the inner container, the peripheral shell having, around the main opening, a peripheral lip, and opposite the evacuation conduit, a point extending between the peripheral lip and a lower surface of the peripheral shell, projecting from the peripheral lip, to a free end.

[0002] The implantable port is used in particular for the injection of a liquid, such as a liquid drug or a diagnostic product such as a contrast agent, into a patient's body during medical treatment.

[0003] Some medical treatments require periodic injections of a liquid medication into a patient's body. Such periodic injections are common, for example, in oncology, dialysis, and the treatment of hemophilia or other chronic diseases. Various medical imaging techniques also require the injection of a contrast agent.

[0004] To avoid damaging the patient's vascular system by repeated needle punctures directly into the patient's vascular system, it is known to insert an implantable port of the aforementioned type under the skin of a patient, for example in the chest, and connect it by means of a catheter to the patient's vascular system.

[0005] The implantable port is arranged under the skin in such a way that the septum is oriented towards the skin, and the implantable port is held in position.

[0006] To implant a chamber of the aforementioned type, it is known to make an incision in the patient's skin, then insert the chamber by its tip under the patient's skin by pushing the chamber through the incision.

[0007] The pointed tip of the chamber facilitates implantation by allowing for gradual insertion under the skin. However, in some cases, this step remains traumatic for the patient and can lead to injury to the patient's skin and / or subcutaneous tissues.

[0008] One aim of the invention is to obtain an implantable chamber that can be easily inserted under a patient's skin, with a reduced risk of trauma to the patient.

[0009] To this end, the invention relates to an implantable chamber of the aforementioned type, characterized in that, in a median vertical plane containing the free end, the ratio between: the vertical radius of curvature of the tip, taken between the peripheral lip and the free end; and the distance separating the projection of the peripheral lip onto the lower surface closest to the free end and the projection of the free end onto a plane defined by the lower surface is between 2.0 and 4.0.

[0010] The implantable port according to the invention may comprise one or more of the following features, taken individually or in any technically feasible combination: the ratio between: the vertical radius of curvature (RV) of the tip, taken between the peripheral lip and the free end; and the distance separating the projection of the peripheral lip onto the lower surface closest to the free end and the projection of the free end onto a plane defined by the lower surface is between 2.3 and 2.7; the ratio between: the vertical radius of curvature of the tip, taken between the peripheral lip and the free end; and the distance separating the projection of the peripheral lip onto the lower surface closest to the free end and the projection of the free end onto a plane defined by the lower surface is between 3.5 and 3.7;The peripheral shell defines, along the lower surface at least around the tip, a rounded lower peripheral edge, the ratio between the radius of curvature of the lower peripheral edge and the maximum height of the peripheral shell being between 0.06 and 0.10; the outer peripheral shell defines, along the peripheral lip at least opposite the tip, a rounded upper edge, the ratio between the radius of curvature of the rounded upper edge and the maximum height of the peripheral shell being between 0.15 and 0.21; the tip has a horizontal radius of curvature at the free end, the ratio of the vertical radius of curvature to the horizontal radius of curvature being between 0.3 and 1.5; the ratio between the maximum height of the peripheral shell and the maximum width of the peripheral shell is between 0.45 and 0.55;the ratio between the maximum length of the peripheral shell and the maximum width of the peripheral shell is between 1.20 and 1.40; the ratio between the height of the highest point of the septum, taken from the lower surface, and the maximum height of the peripheral shell is between 0.95 and 1.05; the height separating the point of the septum closest to the bottom of the internal volume and the bottom of the internal volume is greater than 2 mm.

[0011] The invention also relates to a processing device comprising: an implantable port as defined above; a needle, in particular a Huber needle intended to be inserted into the septum of the implantable port.

[0012] The invention will be better understood upon reading the following description, given solely by way of example, and made with reference to the attached drawings, in which: [ Fig 1 ] there figure 1 is a schematic view of a first treatment kit comprising an implantable chamber according to the invention; [ Fig 2 ] there figure 2 is a cross-sectional view along a median vertical plane of the implantable chamber of the figure 1 ; Fig 3 ] there figure 3 is a view from below of the implantable chamber shell of the figure 2 ; Fig 4 ] there figure 4 is a cross-sectional view along a median vertical plane of the implantable chamber shell of the figure 2 ; Fig 5 ] there figure 5 is a view analogous to the figure 4 of another implantable chamber according to the invention; [ Fig 6 ] there figure 6 is a view analogous to the figure 4 of yet another implantable chamber according to the invention.

[0013] In all that follows, the terms "horizontal" and "vertical" are understood with respect to the orientations of the implantable chamber when its lower surface is placed on a flat horizontal surface.

[0014] A first necessary 10 injection of liquid into a patient is shown on the figure 1 . Such a necessary 10 is intended in particular for injecting a liquid.

[0015] The injected liquid is, for example, a medication. Alternatively, the liquid is a non-therapeutic liquid, such as a diagnostic product, particularly a contrast agent for medical imaging. The contrast agent allows for the creation of an image of the patient's vascular system, for example, by computed tomography (CT scan).

[0016] The necessary 10 comprises, from upstream to downstream, an injection device 12 placed outside the patient's body, a needle injection device 14 intended to be inserted through the patient's skin 16 and a first implantable chamber 18 according to the invention, disposed under the patient's skin 16 and hydraulically connected downstream to the patient's vascular system.

[0017] The injection device 12 includes, for example, a cylinder pump suitable for distributing a liquid with an adjustable volumetric flow rate.

[0018] The injection device 12 is connected to the injection device 14 by an outlet tube 26.

[0019] The needle device 14 may include an intermediate flexible tubing 28 connected in a removable manner to the outlet tubing 26, an injection needle 30 suitable for being inserted into the patient's skin 16 to enter the chamber 18 and a needle gripping mechanism 32 which will not be described in detail.

[0020] The needle 30 is advantageously a bent needle, also known as a "Huber" needle. It has a hollow tubular body 31 defining an internal lumen for the flow of the product. It is connected upstream to the intermediate tubing 28. Downstream, it has a free, beveled end 34 designed to facilitate the insertion of the needle 30 through the skin and into the chamber 18.

[0021] Needle 30 is advantageously non-carcasing. "Non-carcasing" means that needle 30 is capable of piercing a septum without producing solid fragments that detach from it. To measure the non-carcasing nature of needle 30, a test according to Annex D of Standard NF EN ISO 10555-6 of August 2017 is, for example, carried out.

[0022] The non-carving character of the needle 30 is obtained for example by arranging the bevel in a plane parallel to the axis of the hollow tubular body 31 at the level of the free end 34 so that the internal light of the needle is not visible when viewed in its main axis.

[0023] Alternatively, the needle device 14 is of the type described in the Applicant’s French applications FR 2 869 806 and FR 2 886 857.

[0024] As illustrated by the figures 1 à 4 , chamber 18 comprises a base body 40 delimiting an internal volume 42 for receiving liquid (see figure 2 ), a septum 44 closing the internal volume 42 and intended to be punctured by the needle 30, and a conduit 46 for evacuating the liquid out of the internal volume 42 into the patient's body.

[0025] The basic body 40 comprises an inner container 50 with a central axis AA' and an outer peripheral shell 52 which, in this example, is snapped onto the inner container 50.

[0026] In this example, the container 50 comprises a metal liquid receiving tank 54, a lower insert 56 mounted around the tank 54 and a septum retaining ring 58 44 disposed above the tank 54. Alternatively, the tank 54, the insert 56 and the ring 58 are made of a single piece.

[0027] The tank 54, for example, is made of titanium. It has a bottom 60 which delimits the bottom of the internal volume and partially that of the chamber 18, and a substantially cylindrical side wall 62 which laterally delimits the internal volume 42.

[0028] The lateral wall 62 has an annular shoulder 64 for supporting the septum 44, extending along its upper edge. This shoulder defines a lower surface 65 for clamping the septum 44.

[0029] The insert 56 extends around the side wall 62 of the tank, under the annular shoulder 64.

[0030] The ring 58 extends opposite the annular shoulder 64 and defines a superior surface 66 for clamping the septum 44.

[0031] The internal volume 42 is delimited between the side wall 62 and the bottom of the tank 54. The volume 42 opens upwards through a main upper opening 68 receiving the septum 44. It opens laterally through the side wall 62 of the tank by a radial product discharge opening 70. The radial opening 70 has a smaller cross-sectional area than the cross-sectional area of ​​the main opening 68.

[0032] The insert 56 defines a radial passage through which the conduit 46 extends.

[0033] The peripheral shell 52 is made of plastic, for example polyoxymethylene or POM. It extends around the insert 56 and the ring 58, to hold the ring 58 and the insert 56 in position on the tank 54.

[0034] The peripheral shell 52 has a lower surface 72 which is flush with the bottom 60 of the container 50 and a concave lateral surface 74 which extends from top to bottom from the ring 58 to a lower peripheral edge 76 of the peripheral shell 52 located in the vicinity of the lower surface 72.

[0035] The peripheral shell 52 has a peripheral upper lip 78 substantially parallel to the lower surface 72.

[0036] The peripheral edge 76 defines the outer contour of chamber 18. In this example, as illustrated by the figure 3 , this outline is roughly triangular in shape.

[0037] Thus, the peripheral shell 52 has, opposite the evacuation conduit 46, a point 79 which protrudes from the peripheral lip 78 along the axis BB' of the evacuation conduit 46 to a free end 81.

[0038] The peripheral lip 78 projects radially towards the axis AA' around the upper opening 68. It rests here on the ring 58, around the main opening 68.

[0039] The peripheral lip 78 defines, with the lateral surface 74, a rounded upper edge 80 which extends over the entire periphery of the lip 78.

[0040] Advantageously, with reference to the figure 4 The ratio R1 between the radius of curvature RBS of the rounded upper edge 80 and the maximum height HC of the peripheral shell 52, measured vertically between the lower surface 72 and the peripheral lip 78, at the level of the orthogonal projection P1 of the annular lip 78 onto the lower surface 72, closest to the free end 81, is between 0.15 and 0.21. In the example shown on the figure 4 , the R1 ratio is between 0.15 and 0.20, specifically between 0.15 and 0.17.

[0041] The orthogonal projection P1 is taken here at the point from which the peripheral lip 78 begins to protrude towards the axis A-A'.

[0042] The radius of curvature (RBS) of the rounded upper edge 80 is preferably between 1.5 mm and 2.5 mm, in particular between 1.7 mm and 2.1 mm. In the example shown on the figure 4 , the RBS radius of curvature is between 1.9 mm and 2.1 mm.

[0043] The rounded upper edge 80 with the aforementioned dimensions limits the aggressiveness to the patient's skin, during the insertion of chamber 18 under the patient's skin and during the duration of implantation.

[0044] The lower peripheral edge 76 is convex. It is rounded all around the peripheral shell 52.

[0045] Advantageously, the ratio R2 between the radius of curvature RBI of the lower peripheral edge 76, and the maximum height HC of the peripheral shell 52, as defined above, is between 0.06 and 0.10. In the example shown on the figure 4 , the R2 ratio is between 0.06 and 0.08, in particular between 0.06 and 0.07.

[0046] The radius of curvature RBI of the lower peripheral edge 76 is preferably between 0.5 mm and 1.1 mm, in particular between 0.7 mm and 0.9 mm.

[0047] Similarly, the lower peripheral edge 76, having the aforementioned dimensions, limits the aggressiveness to the patient's skin and subcutaneous tissues when inserting chamber 18 under the patient's skin.

[0048] Point 79 is curved vertically and horizontally.

[0049] With reference to the figure 4 , in a median vertical plane PV containing the free end 81, the plane PV passing here through the axis BB' and through the axis A-A', the tip 79 has a vertical radius of curvature RV taken on the lateral surface 74 between the upper edge 80 and the lower edge 76.

[0050] According to the invention, the ratio R3 between the vertical radius of curvature RV of the tip 79 and the distance DP separating the projection P1 defined above and the projection P2 of the free end 81 onto a horizontal plane PHS defined by the lower surface 72, is between 2.0 and 4.0. Advantageously, the ratio R3 is between 2.3 and 2.7, and in the example of the figure 4 between 2.5 and 2.6.

[0051] This ensures a very effective insertion of the 79 tip under the skin, while limiting the size of the incision required, and the aggressiveness on the skin.

[0052] Advantageously, the vertical radius of curvature RV is between 8 mm and 25 mm, particularly between 9 mm and 15 mm. In the example of the figure 4 , the vertical radius of curvature RV is between 13 mm and 15 mm.

[0053] In a horizontal plane PH passing through the free end 81, parallel to the lower surface 72, the tip 79 has a horizontal radius of curvature RH, as visible on the figure 3 .

[0054] The ratio R4 between the vertical radius of curvature RV and the horizontal radius of curvature RH is between 0.3 and 1.5, specifically between 0.3 and 0.6. In the example of the figure 4 The R4 ratio is between 0.5 and 0.6. This also limits the aggressiveness on the skin.

[0055] Advantageously, the horizontal radius of curvature RH is between 15 mm and 30 mm, preferably between 19 mm and 26 mm.

[0056] In the example shown on the figure 4 , the horizontal radius of curvature RH is between 24 mm and 26 mm.

[0057] More generally, the ratio R5 between the maximum height HC of the peripheral shell 52, as defined above, and the maximum width LAM of the peripheral shell 52, taken at the level of the lower peripheral edge 76, perpendicular to the axis BB', is between 0.45 and 0.55. In the example of the figure 4 , this R5 ratio is between 0.53 and 0.55.

[0058] Similarly, the ratio R6 of the maximum length LOM of the peripheral shell 52, taken along the B-B' axis, to the maximum width LAM, as defined above, is between 1.20 and 1.40. In the example of the figure 4 , the R6 ratio is between 1.35 and 1.38.

[0059] These R5 and R6 ratios further reduce the size of the incision, and increase the stability of the implantable chamber 18 under the skin.

[0060] The peripheral shell 52 further delimits through openings 82 for the passage of a suture thread and a radial opening 82A for the passage of the fluid evacuation conduit 46.

[0061] The passage openings 82 connect the lateral surface 74 to the lower surface 72 in the vicinity of the peripheral edge 76, substantially parallel to the axis A-A'. They are distributed angularly around the axis A-A'.

[0062] The maximum diameter of the openings 82 is advantageously between 1.5 mm and 2.5 mm, particularly between 1.6 mm and 2.1 mm. This prevents cell adhesion within the openings and facilitates the removal of the implantable port 18 when it is necessary to remove it.

[0063] The radial opening 82A opens opposite the evacuation opening 70, which it extends radially with respect to the axis A-A'.

[0064] With reference to the figure 2 The septum 44 comprises a basic block 90, made of a waterproof material. The septum 44 advantageously includes an antimicrobial composition intended to be applied to the needle 30 when the needle is inserted through the block 90, for example an antimicrobial coating covering at least one outer surface of the block 90.

[0065] Block 90 is advantageously made from a matrix of a continuous, solid, and watertight material. This material is, for example, a flexible plastic, such as silicone. Block 90 has an outer contour that is substantially homothetic to that of the main opening 68.

[0066] Block 90 extends substantially transversely with respect to a central axis AA' of needle insertion in the septum 44. It has a maximum height, taken parallel to the axis A-A', less than its maximum transverse extent, taken perpendicular to the axis A-A'.

[0067] In the example shown on the figure 1 , the septum 44 is formed by a disc with axis AA' having a lower transverse surface 94, intended to close upwards the internal volume 42, a higher transverse surface 96 opposite the lower surface 94 and intended to be placed opposite the patient's skin, and a peripheral surface 98 connecting the surfaces 94 and 96 together.

[0068] When mounting the septum 44 in chamber 18, the block 90 is able to move from a resting configuration to a partially compressed configuration when mounted in the body 40.

[0069] In the compressed configuration, the septum 44 is inserted at its periphery between the lower transverse surface 65 defined by the support shoulder 64 and the upper transverse surface 66 defined by the retaining ring 58.

[0070] Block 90 thus comprises a compressed peripheral region 100 and a relatively less compressed central region 102.

[0071] In the example shown on the figure 2 The compressed peripheral region 100 exhibits axial compression, measured over the height of the septum 44 between surfaces 95 and 96 relative to the resting configuration, exceeding 20%, and advantageously less than 50%. This compression is, for example, between 30% and 50%, and advantageously between 34% and 43%.

[0072] Thus, in the compressed configuration, the average height of the septum 44 in the compressed region 100 is less than 80% and is notably greater than 50% of the average height of the septum 44 in the same region 100 in the resting configuration, or of the average height of the septum 44 taken at the level of the AA' axis in the less compressed central region 102.

[0073] With reference to the figure 2 The ratio R7 between the emergent height HE of the septum 44, defined by the height separating the point P4 of the septum 44 furthest from the lower surface 72 and the orthogonal projection P5 of point P4 onto the lower surface 72, and the maximum height HC of the peripheral shell 52, as defined previously, is between 0.95 and 1.05, in particular between 0.98 and 1.02. In the example of the figure 2 , the R7 ratio is between 0.98 and 1.00.

[0074] This ratio prevents the septum 44 from being too prominent, which facilitates palpation of the peripheral lip 78 through the skin to more easily position the needle 30, especially for thin patients.

[0075] The emerging height HE is for example between 5 mm and 15 mm, in particular between 8 mm and 13 mm.

[0076] The height under septum HS separating point P6 of the septum 44 closest to the bottom 60 of the tank from its orthogonal projection P7 on the bottom 60 of the tank is between 2 mm and 6 mm, in particular between 3 mm and 5 mm.

[0077] This allows the free end 34 of the needle 30 to be fully accommodated in the internal volume 42, to ensure an adequate injection flow rate.

[0078] The compressed peripheral region 100 extends over a ring of width representing less than 35% and advantageously more than 15% of the maximum transverse extent of the septum 44, taken perpendicular to the axis A-A'.

[0079] Preferably, the ratio R8 between the maximum diameter of the septum 44, taken perpendicular to the axis AA', and the uncovered diameter of the septum 44, located inside the peripheral lip 78, is between 1.20 and 1.40, in particular between 1.22 and 1.37. In the example of the figure 2 , this R8 ratio is between 1.30 and 1.37.

[0080] Furthermore, the R9 ratio between the uncovered diameter of the septum 44 and the maximum LAM width of the peripheral shell 52, as defined above, is between 0.40 and 0.60, specifically between 0.45 and 0.55. In the example of the figure 2 , the R9 ratio is between 0.51 and 0.55.

[0081] The area occupied by the compressed peripheral region 100, taken in projection in a plane perpendicular to the axis AA' is thus less than 50%, and is for example between 30% and 50% of the total area occupied by the septum, taken in projection perpendicular to the axis A-A'.

[0082] Thus, more than 10% and advantageously less than 20%, specifically between 12% and 15% of the volume of septum 44 in the resting configuration is displaced towards a central transverse plane of septum 44 in the compressed configuration.

[0083] With reference to the figure 1 , the exhaust duct 46 includes a rigid fitting 188, a flexible tube 190 and a crimping ring 192 of the flexible tube 190 on the rigid fitting 188.

[0084] It protrudes radially from the base body 40 through the radial opening 82A and beyond this radial opening 82A.

[0085] The rigid fitting 188 is formed by a hollow rod assembled on the outer wall 62 of the container around the discharge opening 70. The hollow rod protrudes radially through the radial opening 82A out of the base body 40.

[0086] The tubing 190 is made from a flexible plastic material. It has a length greater than the maximum transverse extent of the base body 40, for example at least twice this maximum extent.

[0087] The tubing 190 extends between an upstream end forced around the free end of the rigid fitting 188 and a downstream free end intended to be placed in the blood circulation conduit.

[0088] The crimping ring 192 is press-fitted into the radial opening 82A to crimp the flexible tubing 190 against the hollow rod 188. It protrudes radially beyond the base body 40 over a length less than that of the tubing 190, for example at least half that of the tubing 190.

[0089] To use the device 10, the implantable port 18 is first positioned under the patient's skin. For this purpose, an incision is made in the patient's skin, and the port 18 is inserted under the skin through the incision, by its tip 79.

[0090] The tip 79 having an R3 ratio of the vertical radius of curvature RV of the tip 79, at the distance DP between 2.0 and 4.0 and advantageously, an R4 ratio of the vertical radius of curvature RV to the horizontal radius of curvature RH between 0.3 and 1.5, its insertion into the incision is favoured, even if the incision is small, while limiting damage to the skin to a minimum.

[0091] This is particularly the case when the ratio R1 of the radius of curvature RBS of the rounded upper edge 80 to the maximum height HC of the peripheral shell 52 is between 0.15 and 0.21 and advantageously, when the ratio R2 of the radius of curvature RBI of the lower peripheral edge 76 to the maximum height HC of the peripheral shell 52 is between 0.06 and 0.10.

[0092] Thus, the implantation of the implantable port 18 is very minimally invasive and remains simple to perform.

[0093] The implantable port 18 shown on the figure 5 differs from the one illustrated on the figure 4 in that the ratio R1 of the radius of curvature RBS of the rounded upper edge 80 to the maximum height HC of the peripheral shell 52 is between 0.19 and 0.20.

[0094] The ratio R2 of the radius of curvature RBI of the lower peripheral edge 76 to the maximum height HC of the peripheral shell 52, is between 0.07 and 0.08.

[0095] The ratio R3 of the vertical radius of curvature RV from tip 79 to distance DP is between 2.4 and 2.5.

[0096] The ratio R4 of the vertical radius of curvature RV to the horizontal radius of curvature RH is between 0.35 and 0.45.

[0097] The ratio R5 of the maximum height HC of the peripheral shell 52 to the maximum width LAM of the peripheral shell 52 is between 0.47 and 0.51.

[0098] Similarly, the ratio R6 of the maximum length LOM of the peripheral shell 52 to the maximum width LAM of the peripheral shell 52 is between 1.20 and 1.25.

[0099] The ratio R7 between the emergent height HE of the septum 44 and the maximum height HC of the peripheral shell 52 is between 0.97 and 0.99.

[0100] The R8 ratio between the maximum diameter of septum 44 and the uncovered diameter of septum 44 is between 1.20 and 1.30.

[0101] The R9 ratio between the uncovered diameter of the septum 44, and the maximum LAM width of the peripheral shell 52 is between 0.48 and 0.51.

[0102] The implantable port 18 shown on the figure 6 differs from the one illustrated on the figure 4 in that the ratio R1 of the radius of curvature RBS of the rounded upper edge 80 to the maximum height HC of the peripheral shell 52, is between 0.20 and 0.21.

[0103] The ratio R2 of the radius of curvature RBI of the lower peripheral edge 76 to the maximum height HC of the peripheral shell 52, is between 0.08 and 0.10.

[0104] The ratio R3 of the vertical radius of curvature RV from tip 79 to distance DP is between 3.5 and 3.7.

[0105] The ratio R4 of the vertical radius of curvature RV to the horizontal radius of curvature RH is between 1.0 and 1.2.

[0106] The ratio R5 of the maximum height HC of the peripheral shell 52 to the maximum width LAM of the peripheral shell 52 is between 0.49 and 0.52.

[0107] Similarly, the R6 ratio of the maximum length LOM of the peripheral hull 52 to the maximum width LAM is between 1.25 and 1.35.

[0108] The ratio R7 between the emergent height HE of the septum 44 and the maximum height HC of the peripheral shell 52 is between 1.01 and 1.03.

[0109] The R8 ratio between the maximum diameter of septum 44 and the uncovered diameter of septum 44 is between 1.20 and 1.30.

[0110] The R9 ratio between the uncovered diameter of the septum 44, and the maximum LAM width of the peripheral shell 52 is between 0.44 and 0.48.

Claims

1. Implantable chamber (18), suitable for implantation under the skin of a patient, comprising: - a hollow base body (40) delimiting an internal volume (42) for fluid circulation, the internal volume (42) opening through a main opening (68); - a septum (44) closing the main opening (68), the septum (44) being intended to be punctured by a needle (30);- a liquid discharge conduit (46) from the inner volume (42) projecting away from the base body (40), the base body (40) comprising an inner container (50) and an outer peripheral shell (52) assembled onto the inner container (50), the peripheral shell (52) having, around the main opening (68), a peripheral lip (78), and opposite the discharge conduit (46), a point (79) extending between the peripheral lip (78) and a lower surface (72) of the peripheral shell (52), projecting from the peripheral lip (78), to a free end (81); characterized in that, in a median vertical plane containing the free end (81), the ratio (R3) between: - the vertical radius of curvature (RV) of the tip (79), taken between the peripheral lip (78) and the free end (81); and - the distance (DP) separating the projection (P1) of the peripheral lip (78) onto the lower surface (72) closest to the free end (81) and the projection (P2) of the free end (81) onto a plane defined by the lower surface (72) is between 2.0 and 4.

0.

2. Implantable chamber (18) according to claim 1, wherein the ratio (R3) between: - the vertical radius of curvature (RV) of the tip (79), taken between the peripheral lip (78) and the free end (81); and - the distance (DP) separating the projection (P1) of the peripheral lip (78) onto the lower surface (72) closest to the free end (81) and the projection (P2) of the free end (81) onto a plane defined by the lower surface (72) is between 2.3 and 2.

7.

3. Implantable chamber (18) according to claim 1, wherein the ratio (R3) between: - the vertical radius of curvature (RV) of the tip (79), taken between the peripheral lip (78) and the free end (81); and - the distance (DP) separating the projection (P1) of the peripheral lip (78) onto the lower surface (72) closest to the free end (81) and the projection (P2) of the free end (81) onto a plane defined by the lower surface (72) is between 3.5 and 3.

7.

4. Implantable chamber (18) according to any one of the preceding claims, wherein the peripheral shell (52) defines, along the lower surface (72) at least around the tip (79), a rounded lower peripheral edge (76), the ratio (R2) between the radius of curvature (RBI) of the lower peripheral edge (76), and the maximum height (HC) of the peripheral shell (52) being between 0.06 and 0.

10.

5. Implantable chamber (18) according to any one of the preceding claims, wherein the outer peripheral shell (52) defines, along the peripheral lip (78) at least opposite the tip (79), a rounded upper edge (80), the ratio (R1) between the radius of curvature (RBS) of the rounded upper edge (80), and the maximum height (HC) of the peripheral shell (52) being between 0.15 and 0.

21.

6. Chamber (18) according to any one of the preceding claims, wherein the tip (79) has a horizontal radius of curvature (RH) at the free end (81), the ratio (R4) of the vertical radius of curvature (RV) to the horizontal radius of curvature (RH) being between 0.3 and 1.5 7. Implantable chamber (18) according to any one of the preceding claims, wherein the ratio (R5) between the maximum height (HC) of the peripheral shell (52) and the maximum width (LAM) of the peripheral shell (52) is between 0.45 and 0.

55.

8. Implantable chamber (18) according to any one of the preceding claims, wherein the ratio (R6) between the maximum length (LOM) of the peripheral shell (52) and the maximum width (LAM) of the peripheral shell (52) is between 1.20 and 1.

40.

9. Implantable chamber (18) according to any one of the preceding claims, wherein the ratio (R7) between the height of the highest point (P4) of the septum (44), taken from the lower surface (72) and the maximum height (HC) of the peripheral shell (52) is between 0.95 and 1.

05.

10. Implantable chamber (18) according to any one of the preceding claims, wherein the height separating the point (P6) of the septum nearest to the bottom (60) of the internal volume (42) and the bottom of the internal volume (42) is greater than 2 mm.

11. Treatment device (10) comprising: - an implantable port (18) according to any one of the preceding claims; - a needle (30), in particular a Huber needle intended to be inserted into the septum (44) of the implantable port (18).