MXPA97009871A - Implement access device - Google Patents

Abstract

The present invention relates to an implantable access device (10) comprising: a biocompatible sheath (2) having at least one inlet (216) and at least one opening (22') with a passageway (222) ) extending between them, said inlet opening being adapted to receive a filament (240) for the internal passage of said passageway, said enclosure further including, and arranged in said passageway, a valve assembly (3) comprising a valve (242) and a closing element (220), said valve assembly being adapted to be activated by said filament after the passage of said filament through said inlet orifice, after which a closure, independent of the activation of said valve, by said closing element around said filament before said valve opens to allow access through said passageway, said opening communicating with a reservoir (9) practically cylindrical internal in the shell, said reservoir being defined by a lateral surface (5) extending around a central axis (A) and a lower surface (6), an outlet (P) extending through said shell to along a central outlet channel (CA) from a point of said lateral surface of said reservoir, and a filter assembly (20) disposed in said reservoir, said filter assembly including a first wall (25) permeable to the liquid and practically inner cylindrical a, and separated from said lateral surface of said reservoir, said first wall determining a first annular chamber (32) between said first wall and said lateral surface and a first chamber (30) of the reservoir, interior to said first wall, being said first annular chamber and said first reservoir chamber in fluid communication only through said first wall, and said outlet being in direct fluid communication with said first c mara anul

Description

ACCESS DEVICE ItlPLflNTnBLE BACKGROUND OF THE INVENTION The present invention relates to implantable reservoirs for providing a treatment material, such as a drug in liquid form, directly to an internal site of a patient. Specifically, the invention relates to an implantable reservoir without a septum that has a filter medium for separating particulate matter and bacteria from the liquid injected into the reservoir. Irnplantable devices have been developed for infusion or release of medications at a specific body site, for example, to avoid repeated intravenous, mtracheal or epidural injections and thereby minimize discomfort to a patient. Such devices generally include a shell containing an internal reservoir or chamber with an outlet cannula for connection to a catheter and a self-piercing penetrable septum, all of which are biocompatible. The devices can be implanted subcutaneously, with the septum oriented just below the skin to provide easy access for repeated penetration of the needle. A catheter usually connects the exit cannula of the device to a site remote from the implant site. The medication can be injected through the septum into the reservoir of the device, thereby allowing the release of direct medication at the remote treatment site. Some medical conditions require the installation of a pump-release device with a pump in the patient's body that is capable of releasing the medication at a remote site through a catheter for a prolonged period of time. For example, patients with chronic pain can house such a pump to release an analgesic directly into the central nervous system through the spinal fluid. Said access device can also be installed to fill the medication supply of a drug delivery device with pump. Conventional medial access devices are generally similar to other implantable treatment reservoirs for injecting drugs or for blood sampling, such as access devices to the central venous system. All these devices include a biocornpatible envelope containing an internal chamber or reservoir in fluid communication with the treatment site, i.e., the vascular system, intrathecal space, or epidural space, through a catheter and a septum capable of being closed off. new after being punctured by a needle. The useful life of devices for implantable treatment material that include a septum is limited by the number of punctures that the septum can withstand before it produces leaks, because repeated access slowly degrades the silicone until it finally can not resist * the passage of liquids or other elements that are in communication with the device. On the other hand, expensive hollow needles or filaments are preferably used to access the device to reduce damage to the septum. Such hollow filaments also preferably have a small diameter or gauge, making the septum-containing devices unsuitable for treatments requiring high blood flows. Prior art access devices may cause blockages by the particulate material such as metal filings of needles or other metal present or by parts of the septum, which may be detached as a result of needle pricking. Currently available intraspinal devices and systems include filters that can be found between the syringe and the needle or on the device itself. Several types of filters are currently available. One type, for access devices that have a generally cylindrical internal reservoir, with the exit orifice extending from a point on the cylindrical lateral surface of the reservoir, comprising a cylindrical screen placed in the reservoir and having a diameter practically equal to the internal diameter of the reservoir. A second type, for access devices having an outlet orifice extending from a point on the lower surface of the reservoir, includes a mesh screen placed on the lower surface of the reservoir. This type of trapspinal access device filters can not separate many particulate materials by sieving, because the mesh of such filters is necessarily large to adapt to a satifactory flow. A problem with a finer mesh is that the needles injected into the septum of the device can cause more significant damage to the screen. A second problem is that the screens are placed directly adjacent to the exit orifice, leaving only a small area of the screen that allows the flow through the liquid from the device, ie, and this small area of flow through is easily plugged . In addition, the impedance of the liquid is relatively high for small area filters. U.S. Patent No. 5,137,529 discloses an injection device that contains a filter barrier that extends through the internal injection chamber and separates the injection chamber into an upper portion adjacent to the septum and a lower portion in Open fluid communication with the device's outlet conduit. U.S. Patent No. 5,185,003 discloses a device for injecting medicaments containing a circular cylindrical filter having a conical internal wall and adapting precisely to fit the diameter of the internal cavity of the orifice. Another embodiment described in U.S. Patent 5,185,003 includes a filtering piece in the form of a disc parallel to the plane between the internal cavity of the hole and the catheter exit opening. Therefore, there is a need for implantable non-partitionable treatment access devices capable of filtering the particulate material from the medication that is released at a specific body site. An object of the invention is to provide an implantable treatment access device without partition that can separate the remains of the injected liquid. Another object of the invention is to provide an intraspinal access device without septum for the intrathecal or epidural release of medications that are practically free of particulate material.

BRIEF DESCRIPTION OF THE INVENTION The present invention provides a multi-chamber implantable device without partition that includes an access device that has improved filtering capabilities. The implantable access device of the invention includes a biocompatible casing having at least one inlet opening and at least one opening with a passageway extending therebetween. The casing further includes a valve assembly disposed in the passageway, and the valve assembly includes a valve and a closure element. In use, a filament, such as a needle, is introduced through the inlet opening, activating (opening) the valve to allow access through the passageway. Independent of the activation of the valve, a closure is created around the filament by the closing element before the valve opens. The opening communicates with a practically cylindrical reservoir in the cover, the reservoir being defined by a lateral surface extending around a central axis and a lower surface. An outlet cannula defining an internal channel extending from a point on the inner wall of the reservoir ε extends from the housing and is adapted to accommodate a catheter. A filter assembly is arranged in the reservoir. The filter assembly of the invention includes a first wall permeable to the toroidal liquid, preferably a substantially cylindrical inner cover a, and spaced from the lateral surface of the reservoir. In one form, the diameter of the first wall is sufficiently small so that the inner diameter of the reservoir allows complete 360S of liquid flow through the first wall, effectively utilizing virtually all the specific surface of the first wall as a filtering barrier , in contrast to the limited specific surface area of the filters of known injection devices. The placement of the first wall determines two chambers: a first annular chamber between the first wall and the lateral surface of the reservoir of the shell; and a first chamber of the inner reservoir to the first wall. The first annular chamber * and the first reservoir chamber are in fluid communication only through the first wall of the filter assembly, and the channel of the outlet cell is in direct fluid communication only with the first annular chamber. In some embodiments, the filter assembly of the invention comprises a one-pass filter; for example, a one-pass filter is formed by filter units having only a first wall. In other embodiments, a second liquid-permeable and substantially cylindrical wall may be disposed to form a two-pass filter assembly, the second wall being placed inside and separated from the first wall of the Mitro assembly. The diameter of the second wall is sufficiently small that the diameter of the first wall allows complete 360 ° of liquid flow through the second wall, allowing virtually the entire surface area of the second wall to be useful as a filtering barrier. In these embodiments, the second wall forms a second additional annular chamber within the first chamber of the reservoir. According to the present invention, the liquid injected through the passageway in the filter assembly flows from the first reservoir chamber through the first substantially cylindrical wall, to the first annular chamber formed by the first wall of the filter and the inner wall of the reservoir. The liquid then flows from the first annular chamber to the outlet cannula to the treatment site. In the embodiments having a second wall and a second annular chamber, the injected liquid flows from the first chamber of the reservoir through the second wall to the second annular chamber, through the first wall into the first annular chamber and into the second annular chamber. here to the channel of the exit cannula. According to the present invention, the liquid does not have direct access from the first chamber of the reservoir to the channel of the exit cannula. The implantable device of the invention functions to filter out the remains of the injected liquid. The invention uses the fluid dynamics created by the shape of the walls of the first reservoir chamber to trap the particles in specially designed vivid notches, slots and / or corners. When the device is accessed by a filament and fluid is injected into the filter assembly, a liquid flow is established in the first chamber of the reservoir which promotes the accumulation of particulate material of the liquid in notches, grooves and / or live corners. Notches, grooves and / or sharp corners create static areas of liquid flow (dead spaces) or turbulent flow paths in which the particulate material accumulates. According to the invention, the configuration of the notches, grooves and / or live corners of the first reservoir chamber can be varied to optimize the retention of particulate material. In this way, using the device for implantable treatment material of the invention, substantially particle-free material is released at the treatment site. The implantable device of the invention is especially suitable as an intraspinal access device for the epidural or intrathecal administration of drugs. In one embodiment, the invention provides an implantable access device comprising: a biocompatible sheath defining at least one inlet orifice and at least one opening with a through passage extending therebetween, said inlet orifice being adapted to accommodate a filament in said passageway, said casing further including, and disposed in said passageway, a valve assembly comprising a valve and a closing element, said valve assembly being adapted to be activated by said filament after passage of said filament through said inlet orifice, thereby, a closure is created, independent of the activation of said valve, by said closing element around said filament before said valve is opened to allow access through said valve. said passageway, said opening communicating with a practically cylindrical internal reservoir in the housing, said reservoir being defined by a a lateral surface that extends around a central axis and a lower surface; an outlet extending through said shell along a central outlet channel from a point of said lateral surface of said reservoir; and a filter assembly disposed in said reservoir, said filter assembly including a first liquid-permeable and substantially cylindrical wall interior a, and spaced apart from said lateral surface of said reservoir, said first wall determining a first annular chamber between said first wall and said lateral surface and a first chamber of the inner reservoir to said first wall, said first annular chamber and said first reservoir chamber in fluid communication only through said first wall, and said outlet being in direct fluid communication with said first annular camera.

BRIEF DESCRIPTION OF THE DRAWINGS The foregoing and other objects of this invention, the various features thereof, as well as the invention itself, may be better understood from the following description, when read together with the accompanying drawings in which: Figure IA shows in a manner schematic in section, an irnplantable access device without partition with a two-pass filter of the invention with an internal reservoir and a filter assembly with an embodiment of a valve comprising a passageway, in the closed configuration. Figure IB schematically shows in section, the device of Figure IA in an open configuration.

Figure 2 shows in schematic sectional form, an irnplantable access device without partition with a two-pass filter of the invention with an internal reservoir and a filter assembly with an embodiment of a valve comprising a duckbill type valve. in open configuration. Figure 3 shows a schematic representation, partially in section, of an infusion apparatus incorporating two assemblies according to the invention. In the various figures, the corresponding elements are represented by the same reference numbers.

DETAILED DESCRIPTION OF THE INVENTION The device 10 of the present invention, as shown in Figures 1A, IB and 2, includes a biocompatible sheath 2 having a base plate 7 with radially extending flange. To facilitate manufacturing, the casing 2 can be composed of several parts, for example, part 2 ', part 2' 'and part 2' ''. The casing 2 includes an interior reservoir 9, arranged mainly in the part 2 '' 'defined by the lateral surface 5 and a lower surface 6. As shown, the reservoir 9 is cylindrical (having a diameter D), extending throughout of the central axis A, with a circular cross section perpendicular to the central axis A. In other embodiments, the reservoir © 9 can be "practically cylindrical", including functionally equivalent geometries, such as those having an elliptical or polygonal cross section perpendicular to the axis central A. The flange plate 7 may include a multiplicity of holes through which sutures may be passed to anchor the device to the muscular fascia of a patient. The parts 2 'and 2"include an access hole without partition and a valve / closure assembly 3 that is attached to an opening 22'. The reservoir 9 is in fluid communication with the opening 22 'of the access hole and the valve / closure assembly 3. The part 2' '' includes an outlet P, from which an outlet cannula 11 extends. illustrated embodiment, cannula 11 extends from part 2 '' 'at a first end HA (in which this is integrated with part 2' '' at outlet P) to a second end 11B housing a catheter 13 Figures IA, IB and 2 have a two-step filter assembly 20 shown installed inside the reservoir 9. The side surface 5 of the reservoir 9 is also shown in the figures. As shown in the Figures, the filter assembly 20 comprises a first liquid permeable wall 25 (step 1) and a second liquid permeable wall 27 (step 2). The first wall 25 is practically cylindrical and has a diameter Dw that is smaller than D. The wall 25 permeable to the liquid and is located inside a, and separated from the side surface 5 of the reservoir 9 to allow complete 360 ° of liquid flow through the first annular chamber 32 determined between the first wall 25 and the lateral surface 5. The first wall 25 also determines a first chamber 30. of the inner reservoir to the first wall 25. In the embodiment of Figures IA, ID and 2, the chamber 30 houses a second wall 27 that divides the chamber 30 to rotate a second annular chamber * 34 on one side of the wall 27, leaving the remainder of the chamber 30 on the other side of, and interior to wall 27, as described below in detail. The first annular chamber 32 and the first chamber 30 of the reservoir (as a whole) are in fluid communication only through the first wall 25. According to the invention, the first wall 25, as shown in FIGS. 2, works to separate the particulate material from the liquid injected into the first chamber 30 of the reservoir prior to the entry of this liquid into the chamber 32 and eventually into the internal channel 12 within, and defined by the outlet cannula 11. The channel Inner 12 extends from the first end HA of the exit cannula 11, along the annular canal CA from points on the lateral surface 5 of the reservoir 9, to the second end 11 B of the exit cannula 11. According to the invention, the channel 12 is in direct fluid communication with the first annular chamber 32. The structure of the first wall 25 can be selected to produce the desired filtering capacity. For example, the first wall 25 can be formed by a mesh screen, the porosity of which can also be varied to achieve the desired filtration and the desired liquid flow rates. In the various forms of the invention, different mesh sizes can be used or, alternatively, different forms of filtering material can be used. As shown in Figures IA, IB and 2, the second wall 27 is also "substantially cylindrical" and permeable to the liquid, being placed inside of, and separated from, the first wall 25, determining a second annular chamber 34 within of the first chamber 30 of the reservoir and on the first wall 25 and the second wall 27. The second annular chamber 34 provides the only fluid flow path between the first central part (ie, along the central axis A) of the chamber 30 of the reservoir and the first annular chamber 32. The second wall 27 allows 360Q of liquid flow through the wall 27 towards the chamber 32. According to the present invention, the second wall 27 can take the form of a toroidal substrate extending around the central axis A, and having a plurality of holes 35 extending radially therethrough (and providing the liquid flow paths). The holes 35 provide filtering and separation of the particulate material that is too large to pass through. The number and size of the holes 35 is selected to provide the filtering and desired flow rates. In the embodiment of Figures IA, IB and 2, the substrate also supports the first wall 25, which is fixed to this substrate. In the embodiment of Figures 1A, IB and 2, the second wall 27 is dimensioned to create a sub-chamber 36a of the upper cylindrical resevon and a sub-chamber 36b of the lower cylindrical reservoir, respectively, within the first chamber 30 of the reservoir or. The rectilinear circular cylindrical geometry of these subcarnares of the eßervono provides sharp straight anguloses within the first chamber 30 of the reservoir. During the injection of the liquid into the orifice through the path 22 ', it promotes the accumulation of particulate matter or other debris at the corners and, in some cases, the particulate material and other debris are retained in these corners by currents turbulent With particular reference to the access hole and the valve / closure assembly 3, the parts 2 'and 2"include an open and elongated guide channel 214 communicating with the inlet orifice 216 of the shell. The guide channel can generally have a V-shaped configuration, although other configurations such as U-shaped are suitable. The casing 2 may contain a plurality of guide channels. The open guide channel allows a larger attack area to guide a filament into the inlet of the device. As shown in Figure IB, the device 10 can be accessed by inserting a filament 240, such as a cannulated needle, into an elastomeric part or closure element 220 placed within an insert 230 of the shell that is disposed on the track. in step 222. The insert 230 of the casing used to facilitate the manufacture, although it will be understood that this could also be integrated into the geometry of the casing 2. The elastomeric part 220, in this embodiment, includes a plunger 226 and an opening 242, which ends in a lid 224. The lid 224 may be * of titanium, stainless steel or any other suitable resilient material. The elastomena piece 220 furthermore has a transition region 232 along which the largest diameter decreases to a second smaller diameter. The interaction between the elastomenca piece 220, specifically its transition region 232, and the insert 230 of the shell will create a closure around an access filament. The elastomeric part 220 has a substantially thin wall section 234 above the transition region 232. Furthermore, within the passageway 222 there is a retention p 232a of the filament. The opening 242 of the valve system in the part 2 '' is in fluid communication with the internal reservoir 9 through the opening 22 '. The plunger 226 is located at the distal end of the elastomeric part 220 in a closing fit with the passageway 222. Figure IA shows the opening 242 of the valve system in a closed configuration, and Figure IB shows the opening 242 of the valve system in an open configuration. Normally, the filament 240 will be a needle, although a catter or other rigidly substantial piece could be used. Before moving the plunger out of the passageway 222 and the opening of the opening 242 of the valve system that would allow communication between the filament 240 and the opening 22 ', a closure 233 is first created around the filament 240. The closure 233 is maintained at all times when the plunger 226 and the opening 242 of the valve ßißterna allow communication between the filament 240 and the opening 22 'and the closure is released only after the plunger 226 returns to a closed position within the way of passage 222. The closure 233 is generated when the transition region 232 of the elastomer piece 220 is attracted to the smaller diameter of the insert 230 of the shell, compressing the elastomeric piece 220 against the access filament 240. The piece filament retention 236 is configured with an internal dimension smaller than the external dimension of the access filament 240, such that, when the access filament 240 is introduced at the inlet of the device, the retention piece 236 of the filament expands and applies a force against the access filament 240 to resist its withdrawal from the inlet orifice. The retention piece 236 of the filament may employ a tension release groove or slots 237 to adapt the force applied to the access filament 240 and increase its useful life.

Figure 2 represents the device 10 'which includes another embodiment of the valve of the present invention. The valve of this embodiment is a duckbill valve or inclined conical handle 246 in place of plunger 226 and valve opening 242. The aa 248 has replaced the lid 224. A pin 250 helps to maintain the union between the elasto erica piece 220 'and the lid 248. The piece elastomepca 220' has all the attributes of the piece elasto epca 220. The insert 230 The envelope is substantially equal to the insert 230 of the casing and the rest of the structural elements of this embodiment of the valve system are similar to those described in relation to Figures 1A and 1B. The access filament 240 moves the lid 248 and the elastomer element 220 'to create * a seal 233 around * the filament 240 before the valve 246 opens. When the filament 240 advances, the lid 248 ß moves to open the valve 246 to establish fluid communication between the filament and the internal reservoir 9. The closure 233 is held around the access filament for as long as the valve is open, and the closure 233 does not release until after the valve has been closed. Figure 2 depicts the duckbill valve in its open configuration. In other forms of the invention, one or more access devices of the type described above may also be functional components of a pump infusion apparatus, such as that described in U.S. Patent No. 4,496,343. Turning finally to Figure 3, a schematic view of a device of the present invention is shown as an integrally functioning part of an implantable medical device or an infusion pump 110. The pump infusion apparatus includes two access ports (a primary access port 158 and a secondary access port 160) and pump 166, all within a biocompatible housing 170. Primary access port 158 is coupled to the pump inlet 166 by means of a cannula 11, and the The pump 166 is coupled to the IP inlet of the secondary access hole 160 by means of the tube 138. The pump 166 is selectively operative to drive liquid at its inlet and to eject it towards its outlet. For example, any of the configurations described in Figures IA, IB or 2 can be used for the access holes 158 and 160, except that the access hole 160 has an IP inlet hole (in addition to its outlet orifice P). ) connected to an outlet tube 138 extending from the pump 166. Although the access hole 160 is shown being immersed within a common envelope 170, the present invention also includes embodiments in which the infusion apparatus with pump and The secondary access hole 160 is connected but not immersed in a common envelope. Those skilled in the art will recognize that the invention can be made in other specific ways without departing from the spirit or fundamental characteristics of the invention. The embodiments described herein will be considered, therefore, in all respects as illustrative and not restrictive, the scope of the invention being indicated by the accompanying reiviication, before that by the above description, and all variations of the invention that are included within "the meaning and range of equivalence of claims is therefore intended to be included in them.

Claims (18)

NOVELTY OF THE INVENTION CLAIMS

1. - An implantable access device (10) comprising: a biocompatible sheath (2) having at least one inlet opening (216) and at least one opening (22 ') with a "step" (222) extending path between them, said inlet opening being adapted to receive a filament (240) for passage into said passageway, said enclosure also including, and arranged in said passageway, a valve assembly (3) that it comprises a valve (242) and a closing element (220), said valve assembly being adapted to be activated by said filament after "the step" said said filament through said inlet hole, then "Je which , a closure is created, independent of the activation of said valve, by said closing element around said filament before said valve opens to allow access through said passageway, communicating said opening with a reservoir ( 9) practically cylinder internal rich in the envelope, said reservoir being defined by a lateral surface (5) that extends around a central axis (A) and a lower surface (6); an outlet (P) extending through said shell along a channel "Je central outlet (CA) from a point of said lateral surface of said reservoir, - and a filter assembly (20) disposed in said reservoir , including said 00 filter assembly a first wall (25) permeable to liquid and practical cylindrical interior a, and separated from said side surface of said reservoir, said first wall determining a first annular chamber (32) between said first wall and said lateral surface and a first chamber (30) of the reservoir, interior to said first wall, said first annular chamber and said first chamber of the reservoir being in communication "It flows only through said first wall, and said outlet being in direct fluid communication. with said first annular chamber.

2. The device according to claim 1, further comprising a cannula (11) extending at a first end (HA) of the same des «Je said outlet and having a second end (11B) thereof adapted to house a catheter (13), said salt cannula further defining "an internal channel (12) extending from said first end, along said central channel to said second end.

3. The device according to claim 1, wherein said "filter" assembly further includes; a second wall (27) permeable to the liquid and practically cylindrical, interior to, and separated from said first wall, said second wall determining within said first chamber of the reservoir: a second annular chamber (34) between said second wall and said wall; first wall; and at least one sub-chamber (36a, 36b) of the reservoir, interior to said second wall; said second annular chamber being in communication with the said reservoir only through said second wall and being in fluid communication with said first annular chamber only through said first wall.

4. The device according to claim 3, wherein said filter system includes a sub-stratum that extends around said central axis, said substrate forming said second wall and supporting said first wall.

5. The device according to claim 4, wherein said sub-layer is a rigid material and said second wall is formed by said substrate, said second wall having a plurality of holes (35) extending therethrough.

6. The device according to claim 4, wherein said filter assembly comprises "a second sub-chamber (36a, 36b) of the reservoir, inside said second wall and adjacent to the lower surface of the reservoir.

7. The device according to claim 6, wherein said substrate is a rigid material and said second wall is formed by said sub-layer.said second substrate having a plurality of holes (35) extending radially therethrough.

8. The device according to claim 6, wherein said reservoir sub-arrays comprise one or more sharp corners on the surfaces that define it.

9. The device according to claim 3, wherein said sub-chamber of the reservoir is defined by surface that establishes a main flow path of the liquid that extends to said reservoir sub-chamber and through said second wall, and establishes one. or more turbulent flow paths that substantially occur within said sub-chamber of the reservoir.

10. The device according to claim 3, wherein said sub-chamber of the reservoir is practically cylindrical.

11. The device according to claim 1, wherein said valve comprises a conical seat inclined valve (246).

12. The diaphragm according to claim 1, wherein said valve comprises a piston (226) located in closing position within said passageway, said plunger being adapted to open by forcing said plunger from said closing position by means of the movement of said filament through said path "Je paso.

13. The device according to claim 1, wherein said valve comprises an opening (242), adapted to be opened by the movement of said filament in said valve assembly.

14. The device according to claim 1, wherein said outlet is adapted to be connected to a catheter, a graft or an implanted medical device.

15. The device according to claim 1, wherein said filament is a needle having a tip and, O f \ wherein said casing further includes means for guiding said needle in said inlet orifice.

16. The device according to claim 1, further comprising an infusion apparatus (110) with pump, said infusion pump apparatus including an inlet, an outlet, and a pump (166) for selectively conducting the liquidation that between said inlet to exit said outlet, and coupling means for coupling at least one of said outlet and said inlet of said pump apparatus to said implantable access device. The device according to claim 16, wherein said coupling means includes means for coupling said outlet orifice of said implantable access device to said inlet of said pump infusion apparatus. 18. The device according to claim 16, wherein said implantable device and said infusion apparatus with pump are contained within a common casing (170).