An implantable infusion device with a trans-intestinal port for the transfer of substances from ingestible pills to the device

Abstract

The present invention generally regards the controlled administration of substances through infusion devices implanted in the human body and more particularly has as its object an implantable infusion device with a chronically implantable trans-intestinal port for the transfer of drugs from ingestible pills to the implanted device.

Description

[0001] AN IMPLANTABLE INFUSION DEVICE WITH A TRANS-INTESTINAL PORT FOR THE TRANSFER OF SUBSTANCES FROM INGESTIBLE PILLS TO THE DEVICE

[0002] DESCRIPTION

[0003] Field of the Invention

[0004] The present invention generally regards the controlled administration of substances through infusion devices implanted in the human body and more particularly has as its object an implantable infusion device with a chronically implantable trans- intestinal port for the transfer of drugs from ingestible pills to the implanted device.

[0005] Background of the Invention

[0006] A known system for the controlled administration of a substance from a humanbody-implanted infusion device is known from patent publication n. W0201201 1132. This document discloses a system that comprises:

[0007] • an implantable monitoring unit for the monitoring of the target substance;

[0008] • an infusion device of the substance implantable in the peritoneal cavity comprising a communication and control unit to manage the data arriving from the monitoring unit for the substance release;

[0009] • a carrier of the target substance, to be ingested in order to reach passively the intestinal lumen, made of perforable material, resistant to the gastric acids and with metallic inserts;

[0010] • a refilling station to refill the above-mentioned infusion device and associated to the latter, the refilling station comprising a docking group for the magnetic docking of the carrier and a punching unit for drawing the substance from the carrier.

[0011] The refilling of the drug is devised to take place periodically through the ingestion of a carrier in the form of a capsule containing the desired substance. The invention is particularly suitable for insulin delivery, but it can be extended to other drugs as well. Once ingested by the patient, the carrier passively travels along the digestive system up to a certain intestinal loop, where the infusion group is implanted and where the carrier is magnetically docked by the docking group of the refill device.

[0012] The carrier consists of a capsule that delimits an internal chamber for the substance storage. The capsule is made of a polymeric material, resistant to gastric acids and made of a perforable material, so as to be punchable by a needle of the implanted device.

[0013] Once, the carrier capsule is docked, a needle exits from the implanted device, crosses the intestinal wall and enters the capsule. A motorized system (e.g., a pump) aspirates the drug from the capsule and transfers it into the reservoir of the implanted device, thus guaranteeing its refilling. In this prior disclosure the use of a unidirectional valve is also proposed, sutured on the intestinal wall and defining a passage for the needle, to prevent the reflux of liquids or solids from the intestinal lumen towards the interior of the peritoneal cavity.

[0014] In case the unidirectional valve is not made use of, the needle directly crosses the intestinal wall, to reach the capsule, puncturing and damaging the intestinal tissue. This action is thought to be performed periodically, to refill the implanted reservoir, and always at the same point. This raises the issue of a possible fistula formation due to repeated traumas on the intestinal wall. A fistula in that area may imply infections, inflamed and non-healing tissues, instability of the system, transit of liquids or solids from the intestinal lumen towards the interior of the peritoneal cavity and other problems that would likely require surgical intervention to remove the device and the damaged intestine tract and that may have serious consequences for the patient's health.

[0015] On the other hand, in the embodiment with the unidirectional valve, the positioning of this element is challenging: from a surgical viewpoint, suturing the borders of a small circular (or squared) element to the margins of a hole created in the small bowel tract is not easy. Since the valve thickness is thought to have approximately the same thickness as the intestinal wall, risks of suture instability, leakages of liquids or solids from the intestinal lumen towards the interior of the peritoneal cavity, etc., are relatively high. Even more importantly, surgical positioning would need a perfect alignment between the valve and the needle tip, not easy to achieve.

[0016] Moreover, the known unidirectional valve as disclosed is not provided with elements guaranteeing the maintenance of its center at a precise point. In fact, the valve is thought to be an element separated from the implanted device and not physically connected to it. This may cause misalignments and, in general, movements of the valve with respect to the device, e.g., due to peristalsis, fibrotic reactions of the tissues, or other events. If the valve moves, even slightly, with respect to the device, an effective exit of the needle and a consequent punching of the capsule would be no longer guaranteed.

[0017] Furthermore, the unidirectional valve should open, driven by the mechanical pushing action of the needle, and close when the needle is retracted. However, it is extremely difficult, with a valve having moving elements (leaflets), to guarantee perfect sealing when the valve is closed. Furthermore, at least during needle exit / retraction, liquids and solids can likely diffuse from the intestinal lumen toward the interior of the peritoneal cavity.

[0018] Finally, in the prior disclosure, the needle is connected to an inlet duct connected with the insulin refilling device, which necessarily exits from the device case through a hole. This creates a discontinuity in the device that may raise issues of sterility, sealing ability (biological liquids may penetrate into the device), etc.

[0019] Summary of the Invention

[0020] The present invention has its context in the observation of the above-mentioned system and the recognition of the problems affecting its performance; this brought to the implantable device with a chronically implantable trans-intestinal port for the transfer of drugs from ingestible pills to the implanted device according to the invention, having the essential features of attached claim 1. Advantageous embodiments of the invention are defined by the other claims.

[0021] From a general conceptual standpoint, the present invention resides in a new system design consisting of an implanted device with a chronically implanted trans- intestinal port, also indicated as "chronic port" hereafter, for the sake of brevity, designed to: - guarantee a long-term operation of the implanted system without affecting the tissue integrity due to repeatable punching and thus prevent fistula formation; - facilitate the alignment between the needle and the port during the refilling procedure and prevent the misalignment due to peristaltic movement; - prevent any digestive fluid leakage from inside the intestine to the peritoneal space or inside the device.

[0022] Brief description of the drawings

[0023] The characteristics and advantages of the implanted device with a chronically implantable trans-intestinal port for the transfer of drugs from ingestible pills to the implanted devices according to the present invention will be apparent from the following description of embodiments thereof, provided by way of non-limiting example with reference to the appended drawings wherein:

[0024] - Figures from 1 a to 1d show in isometric view (figures 1 a and 1 c) and in top plan views (figures 1 b and 1d) an implantable device equipped with a port according to the invention, first in isolation (figures 1 a and 1 b) and then in an implanted arrangement (figures 1c and 1 d), schematically represented and with the device needle punching a docked drug-carrying capsule;

[0025] - Figures from 2a to 2c show respective isometric views of different embodiments of a port according to the invention;

[0026] - Figures from 3a to 3c show in isometric view an adapter of the port according to the invention, in a first embodiment being a standalone structure to be assembled to the device (figures 3a and 3b in subsequent assembly steps), and in a second embodiment (figure 3c) being an integral part of the structure of the device;

[0027] - Figures 4a and 4b are, respectively, an isometric and an axial cross-section view of the adapter;

[0028] - Figures from 5a to 5c show, through cross-sections taken on plane V of figure 1 c, subsequent steps of the operation of the needle of the device (rest, punching, retraction);

[0029] - Figure 6 is a cross-section of the device in an operation step alike the one of figures 5a and 5c (rest and retraction), with the needle configured in a different setting;

[0030] - Figures 7a and 7b represent in isometric views respective variant constructions of the wing arrangement of the port;

[0031] - Figures from 8a to 8c are respective top views of the implanted device with the port of the invention, showing the different matching with the gastrointestinal tract wall depending on the length of the wings;

[0032] - Figures from 9a to 9c show the port before, during and after a clamping step of the wing arrangement, respectively;

[0033] - Figure 10 is a depiction of the various steps a surgical procedure for implanting the device;

[0034] - Figures from 1 1 a to 1 1d show in greater detail respective, successive steps of a final stage of the procedure for implanting the device, i.e. the removal of a wing clamping member; - Figures 12a and 12b represent again wing clamping member removal steps according to a variant embodiment of the invention.

[0035] Detailed description of the Invention

[0036] With reference to the above figures, and in particular for the moment to figures from 1 a to 1d, according to the invention, in the context an implanted infusion device 1 of a system for the controlled administration of a substance, having the above-mentioned characteristics as generally outlined in prior art document W02012011132 and not shown in its entirety, a chronic port 2 is provided based on a durable implantable structure that bridges a drug-carrying capsule 3 and the implanted device 1 . The port 2 is actually part of a capsule docking group of the device, and allows a retractable punching means of the device 1 , typically a needle 4, to pass through it and punch the docked capsule 3, allowing the drug to be aspirated without repeatedly punching the gastro-intestinal tissues of the patient, that is to say a portion of the intestine tract 5 (where the capsule travels), and an extraperitoneal pouch 6 (where the device is implanted as will be explained in further detail hereafter).

[0037] The chronic port 2 comprises three main components, as shown in particular by figures 2a-2c and figures 4a-4b: a rigid hollow adaptor preferably taking the shape of two coaxial cylindrical tubes 20, 21 , i.e. a wider base tube 21 and a narrower outer tube 20; a self-sealing septum 24 occupying the housing defined by the tubes; and anchoring means, preferably embodied by a collapsible structure, and more preferably by a flexible wing arrangement 22, 23. The wing arrangement can have different configurations. It can comprise four wings, two horizontal arc-shaped wings 22, and two vertical straight wings 23 as in figure 2a, where the terms horizontal and vertical are to be intended with reference to the orientation as shown in the drawing and that corresponds to an implanted position in the intestine tract where the vertical direction is a direction parallel to the axis of the lumen (elongation of the tract) and the horizontal direction is a crosswise direction. Otherwise, it can comprise two horizontal arc-shaped wings 22 only (figure 2b) or two straight vertical wings 23 only (figure 2c). A different number and configuration of the wings can also be devised. The chronic port shape allows it to be fixed inside the device and cross the tissues to access the intestinal lumen. The wings can hold the adapter in its position precisely where the needle exits and avoid misalignment between the device and the capsule, and they may cooperate with a magnetic arrangement that can be implemented according to the prior art and is not part of the present invention.

[0038] The outer tube 20 of the adaptor is configured for direct contact with the tissue, while the base tube 21 is the part of the adaptor that is connected or integral with the implanted device 1 . The outer tube 20 is surgically positioned through the intestinal tissue to ensure the long-term stability of the implant. The diameter of outer tube 20 can range from 2.5 to 8 mm, with a preferred size of 5 mm, ensuring an optimal pathway for the needle while also providing sufficient space for the placement of the self-sealing septum. The base tube 21 is responsible for securely blocking the port within the device 1 . It can be with a diameter ranging from 8 to 12 mm, which allows for stable assembly inside the device, with a preferred size set at 8 mm.

[0039] As made clear by figures 3a-3c the adaptor can be a standalone structure that is subsequently assembled and securely sealed to a seat 21 a formed in the device 1 (figure 3a), or more properly the case of the device. This can be achieved by a variety of means, including mechanical interference, screwing, gluing, welding, or other fixation methods. These approaches create a unitary piece (figure 3b) ensuring an effective seal that prevents fluid ingress through the discontinuity 21 b between the adaptor and the device. Alternatively (figure 3c), the adaptor can be part of the device case itself, with the device wall that integrally forms a protrusion that constitutes the outer tube 20.

[0040] The adaptor can be made of materials that guarantee long-term implantability and stability in the intestinal environment, i.e., a material that intestinal fluids and enzymes cannot degrade (e.g., Titanium, Titanium alloys, Nitinol, etc.). Outer tube 20, which is devised to be in contact with the intestinal tissues, can be provided with particular surface roughness, even at the micro / nanoscale (e.g., through plasma spraying, sputtering, ion deposition, etching, anodization, laser modification, hydrothermal techniques, electric discharge machining, or other techniques), to promote cell and tissue adhesion and proliferation, thus to accelerate the healing of the lesion created on the intestinal wall, needed to insert the port, and stable integration of the device with the tissue. Outer tube 20 could also be provided with a coating (metallic, ceramic, or polymeric) to foster the abovementioned function. Such coating could also provide a micro / nano surface roughness and embed drugs, growth factors, or other agents facilitating healing and tissue integration. Anti-inflammatory or anti-fibrotic agents could also be embedded to avoid an excessive tissue reaction, which may result in an undesired thickening, compromising the overall device function.

[0041] The self-sealing septum 24, as mentioned and as more clearly shown by figure 4b, is located inside the adaptor and represents the material to be punched by the needle 4 of the device. In this sense, it is made of a punchable polymeric material with self-sealing properties, to be easily punched by a needle 4, and when the needle retracts, closing again, avoiding fluid leakage. Generally speaking, the septum prevents any fluid leakage from the intestinal tract to the implant device's internal components and the tissue encompassing the implanted device 1 . This property / behavior is maintained over several cycles of punching / retraction, as discussed hereafter in further detail. The needle is driven by a linear actuation system action, a non-limitative example of which, as depicted in figures 5a-5c, comprises a DC-motor 1 1 , a rack 13 and pinion gears 12. The needle action is shown in a rest position in figure 5a, when punching the docked capsule 3 through the adaptor (more precisely, its septum) in figure 5b, and again retracted (and the septum self-sealed) in figure 5c. In this arrangement the rest and retracted positions of the needle are without contact with, or in any case disengaged with, the septum. On the other hand, as shown by figure 6, the needle can be pre-inserted within the septum (for 1 -2 mm), thus having its starting or rest position within the same septum. This preinsertion assists in minimizing needle buckling as it traverses the septum material and tissue.

[0042] A radial pressure stressing the septum helps the material to help in closing itself after each punch. To guarantee such pressure, the radial dimension of the septum, before insertion in the tubes 20-21 may be 10-20% greater than the internal dimension of the tubes. This ensures that the septum is forcefully pressed into place, aiding in the closure of the hole after each needle penetration. Furthermore, the adapter's dimension can be gradually adjusted over time by an actuator to sustain radial pressure on the septum after multiple penetrations. This approach prevents fluid ingress, enabling prolonged device operation without needing replacement.

[0043] The septum can be made of materials that guarantee punchability and, at the same time, self-sealing behavior for a high number of cycles and resistance to intestinal fluids and enzymes. Possible materials suitable for this purpose are, but not limited, silicones and thermoplastic elastomers with self-sealing capabilities. In this respect, tests were made using a septum made of silicone rubber (MED-6215, NuSil™ Technology LLC, Carpinteria, 1 :10 ratio). Initially, a degradation test was conducted on six septa to verify the durability of the silicone materials using simulated intestinal fluids over three months. The simulated intestinal fluid adhered to USP specifications (Test Solutions, United States Pharmacopeia 35, NF 30, 2012). In brief, 300 mL of simulated intestinal fluid was prepared by dissolving 2.04 g of monobasic potassium phosphate in 100 mL of water, followed by the addition of 23.1 mL of 0.2 N NaOH. The volume was adjusted to 300 mL to achieve a pH of 6.8. Finally, 3 g of pancreatin was added, and thorough shaking was employed to dissolve the enzyme and prevent precipitation. Subsequently, 2 mL of the prepared fluid was placed in a 24-cell well plate, with septa inserted into the cells. The setup underwent continuous shaking and was maintained at 37°C to simulate body temperature. The samples' weights were measured before and after the degradation test: the mass properties of the samples exhibited no changes over the 3-month period. This observation suggests that the material does not degrade over time when exposed to simulated intestinal fluids.

[0044] Additionally, to ensure the long-term functionality of the punching system, the pierceability of the septum was assessed using designated needle sizes, including but not limited to 25 G and 27 G, across various septum thicknesses. In summary, the force required to puncture the septum was measured using specialized non-coring needles of 27 G and 25 G (Hamilton, Romania). The needle was connected to a load cell (Nano17, ATI Industrial Automation, US) and linearly actuated at 10 mm / s through a motorized linear stage (Physik Instrumente, GmbH). The punching force was found to vary based on both the septum thickness and the needle size. Both higher thicknesses and needle size increased the punching forces.

[0045] Cylindrical septa were fabricated using self-sealing implantable silicone (MED- 6215, NuSil™ Technology LLC, USA) through silicone casting at 120°C for 18 minutes. These septa were then inserted into 3D-printed septum holders, filled with 1 ml of fluorescent water (Sodium fluorescein, Merck) with a concentration of 0.006 M. The sealing and healing properties of the septa were assessed by placing the septa within a septum holder, which compressed the septa radially by approximately 10% of their diameter. Then, four septa were subjected to repetitive puncturing (500 times) with 27G needles, actuated by a motorized linear slider (VT-80-100 mm, Physik Instrumente, Germany). Then, after punching, the septa with septum holder were immersed in a 50 mL Falcon filled with 5 mL of distillled water and kept in an incubator for 24 h at 37°C. After that, fluorescent absorption measurement was performed with VICTOR NIVO (Multimode plate reader, PerkinElmer).

[0046] The spectrum of absorbance demonstrates that even after 500 repetitions, the septa consistently maintained their structural integrity throughout the punctures. This was corroborated by fluorescence measurements of the water used to immerse the septa for 24 hours after punching. The absorption signal was very low compared to the calibration data of leakage of 10 pL. These findings suggest that even after 500 punches, which is equivalent to more than 9.6 years of periodic puncturing of the septum, assuming that a patient should ingest one capsule per week, the system will ensure operation.

[0047] Returning to the flexible wing arrangement of the preferred embodiment, and referring more specifically to figures 7a and 7b, the wings are thin structures having a shape memory behavior that helps keep the distal part of the chronic port in a precise position in the intestine and reducing the movement of the implanted system caused by peristalsis and other disturbances. A material that for example can be used is Nickel titanium (Nitinol) shaped in form of bent wires 22a (Figure 7a) or thin plates 22b (Figure 7b).

[0048] As mentioned, different numbers and configurations of the wings can be devised. In a variant of the invention, which may be advantageous in some respects, only horizontal wings are devised, as per the example of figures 8a-8c. The wings in the horizontal direction - horizontal anchoring wings - have a twofold function: stabilizing the structure in a desired position and directing the ingested drug-carrying capsule to the intestinal wall, ensuring appropriate contact. To this purpose, the curvature of the horizontal wings can be tailored to the patient’s intestine diameter. A preferred radius of curvature for those wings is between 9 and 12 mm, which reflects one of the selfexpandable metal stents already used for the gastrointestinal tract and compatible with the typical diameter of ingestible pills (9 - 13 mm). The length of the wings may nevertheless vary: they can form a semicircle as in figure 8a, a quarter of a circle as in figure 8c, or other lengths. In a preferred embodiment, the length is one-third of a circle as in figure 8b.

[0049] If present, the wings in the vertical direction - vertical anchoring wings - can be shaped at an angle of about 90° with respect to the adaptor and have a length variable in the range from 3 to 10 mm. These wings can help in keeping the chronic port stable in a desired position.

[0050] The wings can be mounted on either the inner or outer surface of the adaptor. They can also be fabricated directly as a part of the adaptor itself, e.g., by laser cutting. The use of a shape-memory material (e.g., as mentioned, superelastic Nitinol wire or strips), that is to say, a material which can regain their shape even after being closed and straightened, is crucial to enable the surgical implantation of the chronic port while minimizing damage to the tissues. In fact, when implanting the device, a small hole is formed in the pouch 6 and intestine wall 5. The wings are closed / straightened, e.g., through a clamping means, to minimize their diameter and facilitate insertion through such hole. After insertion, the wings are opened again by removing the clamping means. The memory-shape material will allow the wings to recover their original shape.

[0051] Evidence of fabrication parameters that allow the wings to recover the desired shape reliably after closing them is shown in figures 9a-9c, where a wing arrangement having horizontal and vertical wings is made to undergo clamping with a tubular cap 25. In this example the wings were fabricated using Nitinol wire with a diameter of 0.4 mm and shaped to the desired shape using a different brass mold for each type of wing. Subsequently, the Nitinol wire underwent treatment at 550°C for 25 minutes and was assembled with the adapter to achieve the final shape (figure 9a). After fabrication, the elasticity and shape recovery of the wings were evaluated by clamping them with a rigid tubular cap 25 having an internal diameter of 4 mm (figure 9b). The cap was then removed (figure 9c) in order to measure and compare the angle A of the vertical wings and the distance D between the two upper extremities of the horizontal anchoring wings before clamping and after release of the clamping means.

[0052] As shown by the following chart, the angles of vertical wings and distanced of horizontal wings did not suffer a major reduction between the pre-clamping and the postclamping (or release) condition, confirming that the successful use of the present chronic port does not necessitate an increased incision during the implantation procedure.

[0053] The wings can be provided with metallic, ceramic, or polymeric coatings that help their interaction with the intestinal tissues. For example, soft silicones could be used as a coating to minimize the stress on the tissue. Zwitterionic coatings or other anti-fouling polymeric coatings could also be used to minimize the fibrotic reaction of the tissues and, thus, the possible tissue ingrowth on the surface of the wings. These coatings could also embed drugs, growth factors, and anti-inflammatory or anti-fibrotic agents.

[0054] An advantageous surgical procedure for implanting the device and port is now described in greater detail, referring specifically to figure 10.

[0055] First, the device with a chronic port (frame a) is prepared for implantation by applying a clamping means 25 to bring the wings together, as shown in frame b. The clamping means can comprise a tubular cap for housing the wings in the substantially straightened configuration, preventing them from spreading apart. After opening the abdomen through a midline incision to access the intraperitoneal area, the extraperitoneal pouch 6, which will host the device, is created using blunt dissection. The most appropriate intestinal loop 5 is selected, typically from the third jejunal loop after the ligament of T reitz, where it can be brought close to the abdominal wall along a shorter path (frame c). A hole is formed at the level of the chronic port in the pouch and intestine wall to allow the chronic port’s outer part to exit the pouch and enter the intestine loop (frame d). The device with the chronic port is inserted into the pouch (frames e, f). Then, the chronic port is inserted in the intestine and then fixed through suturing (purse suturing) around to fix it in position and prevent leakage (frames g, h). After fixing the chronic port in the intestine, the clamping structure is removed (frame i) using one of the methods that will be discussed here below.

[0056] In fact, different solutions can be devised to clamp the wings, thus limiting the hole size needed during the surgical procedure. The wing clamping means 25 must be resistant enough to keep the wings securely closed during the insertion, but also easy to be removed for the surgeon. As shown in figures 11 a-11 d, one possibility is to make a second incision 26a in the intestinal wall (figure 11 b) after inserting the chronic port with a clamping means such as the tubular cap 25 in the extraperitoneal pouch 6 and the intestine loop 5 (figure 11 a), access the intestinal lumen from there and use a surgical tool 30 to remove the cap 25 (figure 1 1c). Then, see figure 11 d, a suture 26b is applied to suture the incision after the wings are released.

[0057] A removal of the clamping means without additional incisions may also be a feasible and advantageous option. It can be achieved for example by enclosing the wings within a clamping structure made of a soft material dissolving in water. Such a cap will dissolve in the wet environment of the intestinal tissue, causing the wings to be released within minutes due to the pressure they exert on the degradable cap's wall. Such a cap can be made of a commercial hard gelatin capsule, a mainstay in the pharmaceutical industry for delivering precise dosages. This is the optimal choice for medicines and food supplements due to its solubility in the gastrointestinal tract. This ensures that the capsule dissolves efficiently upon ingestion, releasing the encapsulated drug for absorption. In the present application, the capsule facilitates the deployment of the wings of the chronic port.

[0058] Another possibility to avoid the additional incision, with reference to figures 12a and 12b, will be to enclose the wings within a clamping structure, made of a rigid or soft cap, the removal of which is facilitated by designing the cap in two separate halves 50 sutured together through a surgical thread 60 (figure 12a). Once inserted, the surgeon will release the wings by cutting or pulling the suture between the two halves (figure 12b). Then, the two halves 50 will be released and expelled naturally or degrade over time in the intestinal environment.

[0059] Yet another possibility will be to enclose the wings in a disposable introducer (also known as a “Peel-Away” introducer) with a small outer diameter, as used in other medical applications such as vascular access catheter. This solution will allow the surgeon to remove the introducer from the space between the pouch and the intestine after the insertion.

[0060] Yet another option will be to simply tie the wings together by using a winding of surgical degradable or bio-absorbable thread, to obtain a wing bundle of the desired, reduced diameter. In this case, the surgeon will only need to cut the threads or wait for them to degrade to release the wings.

[0061] To summarize, the trans-intestinal port according to the invention allows to avoid punching the intestinal wall repeatedly and thus prevents the risk of forming fistulas and other acute or chronic damages that may lead to the need of device substitution / maintenance.

[0062] The surgical positioning of the port will be much easier and safer than a valve acting as an interface. In fact, a valve sutured to the intestinal tissue is challenging and risky from a surgical viewpoint, and it hardly guarantees perfect sealing and leakage prevention.

[0063] The proposed port is configured to be physically connected to the implanted device and thus guarantees that the needle always hits the center of the punchable port, effectively carrying out the capsule punching and the drug transfer.

[0064] Since there are no elements that open and close, but just a material that is punched, the port guarantees perfect sealing when the needle is retracted. Furthermore, during the needle exit and needle retraction phases, the self-sealing material constantly adheres to the external surface of the needle, thus preventing any diffusion of liquids and solids from the intestinal lumen toward the interior of the peritoneal cavity.

[0065] Being the port physically connected to the device and since the self-sealing material fills the internal cylinder cavity, the device sterility and sealing ability is more easily guaranteed with respect to a solution in which the device case has a hole from which a tube / conduct exits.

[0066] The present invention has been described with reference to preferred embodiments thereof. Variations and / or modifications can be brought to the invention without thereby departing from the scope of the invention itself as defined by the attached claims.

Claims

CLAIMS1. An infusion device for the administration of a substance, implantable in the peritoneal cavity of a patient, the device comprising a substance refilling station comprising a docking group for the docking of a substance carrier of the administered substance, in the form of a capsule to be ingested by the patient to reach passively the intestinal lumen, made of perforable material, resistant to the gastro-intestinal fluids, and a punching unit with retractable punching means for punching the capsule and drawing the substance from it, wherein said docking group comprises a port for the passage of said punching means, said port being configured for the chronic implantation through a gastro-intestinal wall of the patient, said port comprising a self-sealing septum configured to be punched by said punching means.

2. The infusion device according to claim 1 , wherein said septum is made of a polymeric with self-sealing properties chosen between silicone and thermoplastic elastomers.

3. The infusion device according to claim 1 or 2, wherein said port comprises a rigid hollow adaptor defining a housing for said septum and supporting an anchoring means arrangement for anchoring the device to the gastro-intestinal wall.

4. The infusion device according to claim 3, wherein said hollow adaptor comprises two coaxial cylindrical tubes: a wider base tube for connection with a case of the device, and a narrower outer tube for supporting said anchoring means arrangement.

5. The infusion device according to claim 4, wherein said wider base tube is integral with said case.

6. The infusion device according to claim 4, wherein said base tube is connected with said case via an assembling system chosen among: mechanical interference, screwing, gluing, welding.

7. The infusion device according to any of the claims 3 to 6, wherein said anchoring means arrangement comprises a collapsible structure configured to assume a closed position for insertion in a hole of a gastro-intestinal wall of the patient at the implantation stage, and an open position for docking operation inside the gastro-intestinal lumen.

8. The infusion device according to claim 7, further comprising a clamping means adapted to be engaged with said collapsible structure in the closed position forpreventing the release of the same to the open position, and to be removed from said collapsible structure to let the same assume the open position inside the gastro-intestinal lumen.

9. The infusion device according to claim 8, wherein said collapsible structure comprises a flexible wing arrangement, comprising at least two wings projecting from said adaptor.

10. The infusion device according to claim 9, wherein said wing arrangement comprises two horizontal arc-shaped wings, or two straight vertical wings, or two horizontal arc-shaped wings, and two vertical straight wings.

11. The infusion device according to claim 10, wherein said horizontal arc-shaped wings have a radius of curvature between 9 and 12 mm, and an overall length comprised between a semicircle and a quarter of a circle, preferably one-third of a circle.

12. The infusion device according to any of the claims from 9 to 11 , wherein said wings are shaped in form of bent wires or thin plates.

13. The infusion device according to any of the claims from 9 to 12, wherein said wings are made of a shape-memory material, such as Nitinol, possibly provided with a polymeric surface coating.

14. The infusion device according to any of the claims from 9 to 13, wherein said clamping means comprise a tubular cap apt to engage with said wings in the closed position, holding then in a substantially straightened bundle condition.

15. The infusion device according to claim 14, wherein said tubular cap is made of a soft material with dissolving properties in a wet environment.

16. The infusion device according to claim 14, wherein said tubular cap comprises two separate halves sutured together through a surgical thread.

17. The infusion device according to any of the claims from 9 to 13, wherein said clamping means comprises a winding of a surgical degradable or bio-absorbable thread.

18. The infusion device according to any of the claims from 3 to 17, wherein said outer tube devised to be in direct contact with the intestinal tissues is provided with surface roughening treatments, to promote cell and tissue adhesion and proliferation and stable integration of the device with the tissue.

19. The infusion device according to any of the claims from 3 to 18, wherein saidouter tube is provided with a metallic, ceramic, or polymeric coating possibly embedding drugs, growth factors, or other agents facilitating healing and tissue integration, or also anti-inflammatory or anti-fibrotic agents.

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