Abstract:
There are disclosed various dispensing mechanisms for dispensing filamentary material ( 24 ) through a catheter ( 12 ) into a treatment site of a patient, for example into an aneurysm sack ( 20 ) in a patient&#39;s vessel ( 22 ). In one embodiment the assembly ( 100 ) includes a conical material carrier ( 150 ) which is substantially aligned with the dispensing direction, thereby avoiding the need to have a rotating carrier. Another embodiment has a carrier ( 340 ) which is at least partially cylindrical. The carrier ( 150, 340 ) provides for efficient dispensation of filamentary material at substantial dispensing speeds.

Description:
REFERENCE TO RELATED APPLICATION 
       [0001]    This application claims the benefit of U.S. Provisional Application No. 62/008,085, filed Jun. 5, 2014, which is hereby incorporated by reference. 
     
    
     TECHNICAL FIELD 
       [0002]    The present invention relates to apparatus and a method for delivering filamentary material into a patient, in the preferred embodiments to delivery of material endoluminally through a percutaneous entry point. The preferred embodiments can be used for filling an aneurysm, for closing a vessel or other organ, as well as for other medical treatments. 
       BACKGROUND ART 
       [0003]    There are several medical conditions which can benefit from implantation into a patient of a filler material, an embolization or other device, whether temporary or permanent. Examples include the closure of blood vessels or other lumens so as to occlude these. Another example for which such procedures can be particularly useful is in the treatment of aneurysms, where a part of a vessel wall weakens and then expands outwardly to create an enlarged zone of the vessel, often having the form of a sac. This vessel expansion occurs as a result of blood pressure and tends to continue due to further and progressive weakening of the vessel wall. If left untreated, persistent pressure from the blood flow on the weakened wall tissue can lead to eventual rupture of the vessel and consequential haemorrhaging. Treatments for aneurysms have therefore focused on reducing the pressure on the weakened vessel wall, for instance by diverting blood flow or by isolating the weakened vessel wall, for instance by means of a stent graft. Another treatment method involves filling the aneurysm sac with a filler material which stops the flow of blood into the sac and therefore stops or substantially reduces the pressure on the weakened walls. The filler may be an embolization coil, which will cause blood therearound to clot and thus close the sac and provide a protective barrier to prevent vessel rupture. In other instances, the aneurysm may be filled with a biocompatible material, such as a hydrogel or a polysaccharide fibre, which may be of a biodegradable nature. A biodegradable filler performs the same function as an embolization coil, that is to fill the aneurysm sac and provide pressure protection to the weakened vessel walls, with the additional advantage of allowing remodeling of the vessel wall over time. Moreover, biodegradation of the filler will ensure that no foreign matter remains in the patient&#39;s vessel after conclusion of the treatment. 
         [0004]    Such fillers and coils can also be used to close off a vessel or other lumen in a patient. 
         [0005]    The process of introducing such a filler or coil into a patient can take time, particularly given that this is often carried out remotely from the aneurysm by an endoluminal procedure. 
         [0006]    Examples of prior art devices and methods can, for instance, be found in U.S. Pat. No. 6,312,421, US-2006/0147483, U.S. Pat. No. 6,589,199, U.S. Pat. No. 6,440,098. 
       SUMMARY 
       [0007]    The present invention seeks to provide an improved apparatus for delivering filamentary material into a patient and in the preferred embodiments into a vessel or aneurysm sac. 
         [0008]    According to an aspect of the present invention, there is provided apparatus for delivering filamentary material into a patient including: a tubular delivery element having a proximal end, a distal end and a lumen extending within the tubular delivery element from the proximal to the distal ends; a material receptacle having an aperture for receiving driving fluid into the receptacle, and an outlet coupled to the lumen of the tubular delivery element, the outlet extending in a material dispensing direction of the receptacle; a carrier element for carrying filamentary material, the carrier element having an axis substantially aligned with the material dispensing direction of the receptacle and including a body portion around which filamentary material can be wound. 
         [0009]    The carrier element is able to support filamentary material wound thereon and to allow unwinding of the material along the axis of the carrier, which does not require the carrier to rotate. The apparatus therefore need not have any moving parts, although in some embodiments it is not excluded that the carrier may be rotatable about its longitudinal axis. The carrier is preferably substantially aligned with the longitudinal axis of the receptacle. 
         [0010]    The tubular delivery element may be or include at least one of a catheter, a cannula and a needle. 
         [0011]    In the preferred embodiments, the carrier element is precisely aligned with the dispensing direction of the receptacle. In other embodiments, the carrier element is disposed at an angle to the dispensing direction of the receptacle. In such embodiments, the carrier will have a side relatively remote from the outlet of the receptacle and thus to the dispensing direction. This angle is advantageously no more than around 30 degrees relative to the dispensing direction, in practice the longitudinal axis of the receptacle as determined by the direction of movement of the fibre out of the outlet. More suitably, this angle is less than around 20 degrees and even more suitably less than around 10 degrees. In practice, the angle should preferably be less than around 5 degrees. 
         [0012]    Preferably, the body portion of the carrier element is generally round in transverse cross-section. 
         [0013]    In one embodiment, at least a part of the body portion of the carrier element has a generally conical form tapering in a direction towards the outlet. In this embodiment, the body portion of the carrier element may be conical or frusto-conical. Such a form can provide virtually no impediment to unwinding of material from the carrier during dispensation. 
         [0014]    The body portion of the carrier element may include a generally cylindrical portion. In one embodiment the body portion of the carrier element includes a conical portion and a generally cylindrical portion extending longitudinally beyond a narrow end of the conical portion. 
         [0015]    In the preferred embodiments, the carrier element includes at least one driving fluid conduit, advantageously which includes at least one aperture disposed at an end of the carrier element furthest from the receptacle outlet. 
         [0016]    The driving fluid will thus be provided upstream of the wound material, which will assist in its unwinding. 
         [0017]    Preferably, the receptacle includes a tapering internal wall adjacent the outlet. The tapering wall, which is most preferably of conical form, will concentrate the flow of driving fluid and increase the speed thereof into the catheter, thereby increasing the speed of dispensation of the material. 
         [0018]    The apparatus may include a guiding element at an end of the material carrier closest to the outlet, the guiding element in some embodiments being in the form of an annular guide element. The guiding element can assist in the unwinding of the material and feeding of the material to the receptacle outlet. In some embodiments, the guiding element may be a rotating ring of low friction material, such as a low friction polymer, preferably including a hole for the passage of filamentary material therethrough. 
         [0019]    In the preferred embodiment, the material may be small intestine submucosa (SIS), polysaccharide, a biocompatible polymeric thread or other biocompatible material. Specific examples, though the disclosure herein is not limited to these, include: woven polyester (e.g. DACRON®), polyamide (e.g. Nylon), expanded polytetrafluoroethylene (ePTFE; e.g. GORE-TEX®); bioremodelable materials such as: extracellular matrix material (ECM) for instance submucosa, renal capsule membrane, dermal collagen, dura mater, pericardium, fascia lata, serosa, peritoneum and basement membrane layers. Examples of submucosa include: intestinal submucosa, including small intestinal submucosa, stomach submucosa, urinary bladder submucosa and uterine submucosa. 
         [0020]    Advantageously, filamentary material is wound on the material carrier from a distal end thereof to a proximal end thereof, the proximal end being closest to the outlet. Preferably, the filamentary material is wound on the material carrier in sections from the distal end to the proximal end. More preferably, the filamentary material is wound on the material carrier in sections up to a maximum wound diameter on the material carrier from the distal end to the proximal end. In the preferred embodiment the filamentary material is wound first at the distal end of the carrier until at least a part of this reaches a wound diameter around that of the desired maximum diameter of wound material on the carrier, and then the winding continues at a position closer to the proximal end, until the desired diameter is attained at that position, with winding continuing at a next position yet closer to the proximal end, and so on until sufficient material has been wound on the carrier. It is preferred that the material is wound in conical layers on the carrier. 
         [0021]    The receptacle may be at least partially transparent or translucent. The apparatus may include a fluid supply and pump for pumping driving fluid into the receptacle, the pump optionally including a syringe. 
         [0022]    According to another aspect of the present invention, there is provided a carrier for carrying filamentary material deliverable into a patient, the carrier an elongate body portion having a distal end and a proximal end; and filamentary material wound around the body portion, the filamentary material being wound from the distal end of the carrier to the proximal end of the carrier. 
         [0023]    Advantageously, the filamentary material is wound on the material carrier in sections from the distal end to the proximal end, preferably in sections up to a maximum wound diameter on the material carrier. 
         [0024]    Most preferably, the filamentary material is wound in conical layers on the carrier. The filamentary material may be any of the materials or combination of materials disclosed herein. 
         [0025]    In an embodiment, the carrier includes a receptacle fixing element attached to or integral with the distal end thereof. The receptacle may be a closure element. 
         [0026]    According to another aspect of the present invention, there is provided apparatus for delivering filamentary material into a patient, including a receptacle provided with an internal chamber for holding filamentary material, an aperture for receiving driving fluid into the chamber, an outlet through which filamentary material can pass from the chamber, and a pressure sensitive valve associated with the receptacle, the pressure sensitive valve being closed when the pressure of driving fluid is below a threshold and open when the pressure of driving fluid is above the threshold, the pressure sensitive valve when open allowing fluid flow through the chamber and dispensation of filamentary material from the outlet. 
         [0027]    The pressure sensitive valve can ensure that driving fluid is supplied at a sufficient pressure to drive filamentary material through the catheter with minimal use of driving fluid. 
         [0028]    Preferably, the pressure sensitive valve is disposed at at least one of the inlet and the outlet. 
         [0029]    The valve may include at least one resilient valve leaf deformable when fluid pressure thereon exceeds the threshold. 
         [0030]    Advantageously, the valve is domed to provide one-way fluid flow therethrough. Other features of the apparatus and method disclosed herein will become apparent from the following specific description of preferred embodiments. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0031]    Embodiments of the present invention are described below, by way of example only, with reference to the accompanying drawings, in which: 
           [0032]      FIG. 1  is a schematic diagram of an embodiment of material feed apparatus according to an embodiment of the invention; 
           [0033]      FIG. 2  is a side elevational view of an embodiment of material receptacle in exploded form; 
           [0034]      FIG. 3  is a view of the assembly of  FIG. 2  in partially assembled form; 
           [0035]      FIG. 4  shows two views of the assembly of  FIGS. 2 and 3  in schematic form, on which filamentary material is wound; 
           [0036]      FIG. 5  shows another embodiment of material carrier of the embodiment of  FIGS. 2 to 4 ; 
           [0037]      FIGS. 6 and 7  show another embodiment of material carrier; 
           [0038]      FIGS. 8 to 11  show another embodiment of material receptacle and carrier; 
           [0039]      FIGS. 12 to 15  show another embodiment of material receptacle and carrier; 
           [0040]      FIGS. 16A to 16C  show a preferred embodiment of material winding method for winding filamentary material onto a carrier; 
           [0041]      FIGS. 17A to 17C  show in schematic form a catheter in transverse cross-section with one or more filaments of bioabsorbable material held therein; 
           [0042]      FIGS. 18A and 18B  are perspective views of an example of receptacle including a minimum fluid pressure valve; 
           [0043]      FIGS. 19A and 19B  are perspective views of the valve in  FIGS. 13A and 13B  in a closed condition; and 
           [0044]      FIGS. 20A and 20B  are perspective views of the valve in  FIGS. 13A and 13B  in an open condition. 
       
    
    
     DETAILED DESCRIPTION 
       [0045]    There are described below various embodiments of apparatus for feeding filamentary material into a patient. The teachings herein are particularly useful for feeding blocking material into an aneurysm sac of a weakened vessel, so as to close off the aneurysm sac to blood flow and blood pressure. The apparatus can also be used to supply material to occlude a vessel, for example. The material can be of a type which permanently remains in the patient, thus as a permanent closure or occlusion device, or may be bioresorbable or biodegradable, allowing tissue remodeling over time. In the case of aneurysm treatment, once pressure is removed from within the aneurysm sac the weakened wall tissue can remodel and often will heal fully. In such cases, it is not necessary to maintain a sac filler. 
         [0046]    The material is preferably of filamentary form, more particularly as a single or multi strand filament, typically of substantial length. The filamentary material is advantageously of a single length and such that the entire volume of material carried on the material carrier can be delivered by the device into a patient in a single operation. The material could be described as being of thread form. 
         [0047]    Referring to  FIG. 1 , there is shown in schematic form a material dispensing assembly  10  incorporating the features of the embodiments disclosed herein. The dispensing assembly  10  includes a catheter  12  having a proximal end  14  coupled to a material receptacle  16 , described in further detail below, and a distal end  18  which is fed endoluminally through the vasculature of the patient up to the treatment site, into the sac  20  of an aneurysm formed in a blood vessel  22 . The apparatus  10  is designed to dispense into the aneurysm sac  20  filamentary material  24  from the material receptacle  16  through the lumen of the catheter  12 . The material dispensed can be any biocompatible material including biocompatible polymeric thread, polysaccharide or other suitable material. Other examples are SIS (small intestine submucosa). Specific examples, though the disclosure herein is not limited to these, include: woven polyester (e.g. DACRON®), polyamide (e.g. Nylon), expanded polytetrafluoroethylene (ePTFE; e.g. GORE-TEX®); bioremodelable materials such as: extracellular matrix material (ECM) for instance submucosa, renal capsule membrane, dermal collagen, dura mater, pericardium, fascia lata, serosa, peritoneum and basement membrane layers. Examples of submucosa include: intestinal submucosa, including small intestinal submucosa, stomach submucosa, urinary bladder submucosa and uterine submucosa. 
         [0048]    The distal end of the catheter  12  is typically fed into the aneurysm sac through a stent  19 , which may be a braided stent or any other known stent structure. The stent  19  not only positions the distal end  18  of the catheter but also holds the filamentary material in the aneurysm sac. 
         [0049]    The filamentary material  24  is intended to fill at least a significant part of the volume of the aneurysm sack  20  so as to stop the flow of blood into the aneurysm  20  and as a result reduce the pressure of blood on the weakened vessel walls of the aneurysm. In the case of a bioresorbable or bioabsorbable material, this will eventually be resorbed or absorbed, typically after a sufficient period which allows recovery of the weakened vessel wall and remodeling of the vessel. In other cases the fibrous material remains permanently within the aneurysm sac, effectively closing this off. 
         [0050]    The fibrous material is typically provided as a thin thread or element, for which a substantial length is dispensed from the distal end  18  of the catheter  12  into the aneurysm sac  20  during the deployment procedure. For this purpose, and as described below, the material receptacle  16  includes substantial lengths of filamentary material and held within the material receptacle  16  in such a manner that the material can be reliably and quickly dispensed from the receptacle  16  to the distal end  18  of the catheter  12  and into the treatment site. A preferred example of a thread winding method is described below. 
         [0051]    The driving fluid for driving material  18  from the receptacle  16  through the catheter  12  can be provided by a syringe coupled to an inlet to the receptacle, although in other embodiments any other suitable fluid pump may be used. 
         [0052]    It is to be understood that the device  10  shown in  FIG. 1  could be used in other medical procedures, including, for example, for occlusion of blood vessels, for delivery of filamentary material for other medical applications and so on. 
         [0053]      FIGS. 2 to 5  show a first structure of material dispensing assembly  100  for use as the receptacle  16  of  FIG. 1 .  FIG. 2  shows the assembly  100  in exploded view so that the principal components can be readily seen. 
         [0054]    With reference to  FIG. 2 , the assembly  100  includes first and second casing parts  102 ,  104  which can be secured to one another, for example by means of male and female threaded couplings. 
         [0055]    The casing formed by the parts  102 ,  104  has in this embodiment a cylindrical outer form and, as will be explained in further detail below, a conical internal wall  106  in the larger casing part  104 . 
         [0056]    The assembly  100  also includes a base or support element  110  which is generally round in plan and in use resides within a rounded recess  108  of the casing part  102 . The base element  110  also includes a rounded coupling end  114  which fits within a round aperture  112  of the casing part  102 . The rounded coupling end  114  includes an internal bore with a female screw thread (not shown) which co-operates with a male screw threaded element  120  of a luer fitting  118 . The base element  110  may be rotatable within the casing part  102  but in other embodiments may be fixed to the casing part, for example by bonding, welding, by a friction fit or locking element of suitable form (for example a key and associated recess). The base element  110  also includes an raised seal support  124  which provides an annular shoulder for holding an O-ring seal  126 . The seal support  124  has a central round opening  128 , aligned with the threaded bore of the rounded coupling end  114  and in fluid communication therewith. The proximal end  132  of a sleeve  130  fits within the round opening  128  of the base element  110 , fixed preferably by a friction fit, by bonding or welding, for example. The sleeve  130  has a plurality of apertures  134  disposed circumferentially around the sleeve at a mid-portion thereof. The distal end  136  of the sleeve  130  is closed by a rounded closure element  140 , which is a tight fit within the distal end  136  of the sleeve  130 , although may in the alternative or additionally be bonded or welded to the sleeve. The arrangement is such that a fluid passage exists through the luer fitting  118 , the base element  110  and the sleeve  130 , exiting through the openings  134 . 
         [0057]    Attached to the closure element  140  is a conical material carrier  150 . It is to be appreciated that the material carrier  50  could be formed as a unitary component with the closure element  140 , but in other embodiments may be bonded, welded or otherwise fixed to the closure element  140 . 
         [0058]    The casing part  104  includes an outlet  152  having an internal screw thread which co-operates with a male screw threaded element  162  of a female luer connector  160 . 
         [0059]    Most of the components of the assembly  100  shown in  FIG. 2  may be made of a plastics material, although in the embodiments shown the sleeve  130  is usefully made of a metal, which will be able to affect a friction fit with the components  110 ,  140  to which it connects. 
         [0060]    Referring now to  FIG. 3 , this shows the components of  FIG. 2  in substantially assembled form. As can be seen, the casing part  102  includes the O-ring seal  126  and the conical material carrier  150 , the latter being spaced from the base support  110  by a section of the length of the sleeve  130 , specifically by at least the zone of the apertures  134 , such that a fluid path exists between the base element  110  and the conical material support  150 . 
         [0061]    Referring now to  FIG. 4 , this shows the assembly of  FIG. 2  in fully assembled form and loaded with filamentary material. The casing parts  102 ,  104  are shown connected together, with the O-ring seal  126  sealing the chamber  106  formed by the internal walls of the parts  102 ,  104  in fluid tight manner, save for the inlets and outlets to the assembly. As can be seen, a length of filamentary material  24  is wound around the conical material carrier  150 , preferably in a direction from the wide end of the conical carrier  150  to its narrow end, although the direction of winding and number of winding layers may differ from one implementation to another. The free end of the filamentary material  24  passes through the lumen of the outlet  152  and of the female luer connector  160 , to exit the assembly  100 . The material  24  will pass into a catheter  12  attached to the female luer connector  160 , in the manner shown in  FIG. 1 . The male luer connector  118  attached to the inlet to the dispending assembly  100  connects to a source  180  of driving fluid (not shown in  FIG. 4 ), which may be a pump such as a syringe. 
         [0062]    The filamentary material  24  is preferably of a diameter which is a close fit within the catheter  12 . When driving fluid, typically saline solution, is pumped into the dispenser assembly  100  through the inlet luer connector  118 , this will pass into the chamber  106  of the assembly  110  through the apertures  134  of the sleeve  130 . Continued flow of driving fluid will then cause the driving fluid to flow out of the outlet  152  and female luer connector  160 , in practice into a catheter  12  attached to the female luer connector  160 . This driving fluid will pull the filamentary material  24  with the fluid flow, effectively dispensing the filamentary material  24  from the dispensing assembly  100 . The material will unwind from the conical material carrier  150  during the dispensing operation. It is preferred, as described above, that the material carrier  150  is fixed in position, although in some embodiments it may be rotatably attached to the casing portion  102 , in which case the carrier  150  will rotate as the filamentary material  24  unwinds therefrom. 
         [0063]    The dispensing procedure will typically continue until there is no more filamentary material to dispense. It will be appreciated that in this case, there will be provided a length of filamentary material deemed sufficient and required for the particular medical condition. It is not excluded, however, that the dispensing operation could be terminated once the physician has determined that a sufficient of length or volume of filamentary material has been deployed at the treatment site, for example that an aneurysm sac has been filled with material  24 . Once this has been achieved, the remaining filamentary material  24  could be cut by means of a suitable cutting element located either at the distal end of the catheter  12  or adjacent the dispensing assembly  100 . 
         [0064]    A slightly modified version of the embodiment of  FIGS. 2 to 4  can be seen in  FIG. 5 . The primary difference is that the internal components are formed as a single piece. More particularly, there is provided a material carrier  200  which has at a distal end a conical carrier portion  150 ′ and at a proximal end a cylindrical collar  151  with a plurality of circumferentially spaced apertures  134 ′. Beyond the collar  151  is a disk-shaped base element  110 ′, from which there extends a coupling collar  114 ′. The coupling collar  114 ′ has an internal screw thread which co-operates with a male screw threaded element  120  (not visible in  FIG. 5 ) of a male luer connector  118 . The O-ring seal  126  is held against the base element  110 ′ and for this purpose the base element  110 ′ may have a raised annular shoulder for supporting the O-ring seal  126 , in similar form to the shoulder  124  of the base element  110  of  FIG. 2 . The material carrier  200  has a fluid passage extending through the connector sleeve  114 ′ and to the apertures  134 ′, such that fluid can pass through the male luer connector  118  to the apertures  134 ′. The material carrier  200  fits within a casing formed of parts  102 ,  104  substantially the same as those of the embodiment of  FIGS. 2 to 4 . The O-ring seal  126  seals the two parts  102 ,  104  in fluid tight manner to one another, save for the inlet and outlet. The O-ring seal  126  may also prevent rotation of the material carrier  200  within the casing by virtue of a friction fit between the seal  126 , the carrier element  200  and the internal walls of the casing parts  102 ,  104 . 
         [0065]    The operation of the device with the material carrier  200  is the same as that of the embodiments of  FIGS. 2 to 4 . 
         [0066]    Referring now to  FIGS. 6 and 7 , this shows another embodiment of dispenser assembly  300  which includes a casing formed of first and second casing parts  302 ,  304  similar to the casing parts  102 ,  104  of the previously described embodiments. This embodiment also includes a material carrier assembly  310  which includes a first element  320  having a generally conical material carrier portion  322 , a conical base  324  having a plurality of apertures  334  disposed circumferentially therearound, and a connector sleeve element  336  having an internally threaded bore which co-operates with a male threaded connector part of a male luer connector  118 . The element  320  also includes at the large end of the conical portion  324  an annular groove therein (not visible in  FIGS. 6 and 7 ) for holding the O-ring seal  126 . 
         [0067]    At the distal end  340  of the element  320 , there is provided an annular guide element  350  which sits within a suitable groove (not visible in  FIGS. 6 and 7 ) of the element  320 . The guide  350  is preferably made of a very low friction material, such as PTFE or ePFTE. The guide  350  may be fixed to the element  320  but is preferably able to rotate relative to the element  320 . The guide  350  includes a small hole therein (not shown in the drawings) through which the filamentary material can pass. The guide thus assists in feeding the filamentary material to the outlet. 
         [0068]    It is to be appreciated that all the embodiments disclosed herein may be provided with a guide similar to guide  350  of the embodiment of  FIGS. 6 and 7 . 
         [0069]    In all other respects, the embodiment of  FIGS. 6 and 7  is similar to that of the previously described embodiments, with driving fluid being able to pass through the male luer connector  118  from a source of driving fluid (for example a syringe filled with saline solution) and through the apertures  334  into the chamber of the casing element  304  in order to pull filamentary material into the catheter  12 . In this regard, it can be seen in  FIG. 7  that the catheter  12  couples to the female connector luer connector  160  by a male luer connector  312  fixed to the proximal end  14  of the catheter  12 . 
         [0070]    The element  310  may be rotatable within the casing  302 ,  304  but may equally be non-rotatably fixed therein. 
         [0071]    Referring now to  FIGS. 8 to 11 , these show another embodiment of material holder or receptacle  400  in accordance with the invention. The receptacle  400  includes, in this embodiment, a generally cylindrical body part  410  having an open distal end  430  and a closed flat proximal end which terminates with a female luer fitting  420 . The luer fitting  420  couples to an outlet in the closed end of the body part  410  so as to be in fluid communication with the interior chamber of the receptacle  400 . The distal end of the receptacle includes an internal annular shoulder  440  for receiving or cooperating with a closure element  452  of the material carrier  450 . In the embodiment shown, the closure element  452  is a disc shaped cover of a size conforming to that of the open end of the body part  410  so as to be able to seal the chamber of the receptacle  400 . There is provided a raised disc shaped seal holder  454  having an annular groove  456  extending around its periphery for holding an O-ring seal (not shown). The O-ring seal will abut against the inner surface of the body portion  410 , preferably at the shoulder  440 . The seal holder  454  in this example tapers from the closure element  452 , which assists in fitting of the closure element  453  to the body  410 . 
         [0072]    The outer or exposed side of the closure element  452  has fitted thereto a male luer fitting  458  for coupling to a source of driving fluid, for instance a syringe. 
         [0073]    Extending from the centre of the closure element  452  is a material carrier shaft  460 , in the form of a cylinder or shaft having a lumen  470  extending throughout its length and in fluid communication with the luer fitting  458 . The material carrier shaft  460  has a length shorter than the length of the chamber of the receptacle  400 , such that when fitted to the body portion there is a space between the extremity of the material carrier shaft  460  and the outlet from the receptacle chamber. 
         [0074]    Filamentary material is wound onto the material carrier shaft  460 , preferably in the manner described below, and its second or free end is fed into the outlet of the body portion  410 , that is into the lumen leading to the luer fitting  420 . 
         [0075]    In use, fluid is pumped into the chamber of the receptacle  400  via the inlet luer fitting  458 , whereupon it passes through the lumen  470  of the material carrier  450 . The chamber of the receptacle  400  will fill with fluid, enveloping the filamentary material wound on the carrier shaft  460 , which will make it easier to unwind the filamentary material. The pumped fluid will also pass into the outlet  420 , particularly once the chamber has filled with fluid so as to increase pressure in the chamber, and in practice into a delivery catheter attached to the luer fitting  420 . This flow of fluid will pull the filamentary material with it, thereby to deliver the filamentary material through the catheter and into the patient. 
         [0076]    The lumen  470 , which is generally aligned with the outlet  420 , also provides a flow of driving fluid directly into the outlet  420  and therefrom into the attached catheter, which contributes to an increased filament driving force. 
         [0077]    Referring now to  FIGS. 12 to 15 , these show another embodiment of material holder or receptacle  500  in accordance with the invention and similar to the embodiment of  FIGS. 8 to 11 . The receptacle  500  includes, in this embodiment, a generally cylindrical body part  510  having an open distal end  530  and a conical closed proximal end  512  which terminates with a luer fitting  520 . The chamber in the receptacle  500  also has a conical proximal end consistent with its outer shape. 
         [0078]    The luer fitting  520  couples to an outlet in the closed end of the body part  510  so as to be in fluid communication with the interior chamber of the receptacle  500 . The distal end of the receptacle includes an internal annular shoulder  540  for receiving or cooperating with a closure element  552  of the material carrier  550 . In the embodiment shown, the closure element  552  is a disc shaped cover of a size conforming to that of the open end of the body part  510  so as to be able to seal the chamber of the receptacle  500 . There is provided a raised disc shaped seal holder  554 , which may have an annular groove extending around its periphery for holding an O-ring seal (not shown). 
         [0079]    The outer or exposed side of the closure element  552  has fitted thereto a male luer fitting  558 . 
         [0080]    Extending from the centre of the closure element  552  is a material carrier member, comprising a cylinder or shaft  560  and a conical portion  562  adjacent the closure element  552 . The conical portion  562  may terminate short of the closure element  552  to leave a narrow connecting neck, as can be seen particularly in  FIG. 15 . The carrier member has a lumen  570  extending throughout its length and in fluid communication with the luer fitting  558 . The material carrier  560 / 562  has a length shorter than the length of the chamber of the receptacle  500 , such that when fitted to the body portion there is a space between the extremity of the material carrier shaft  560  and the outlet from the receptacle chamber. 
         [0081]    Filamentary material is wound onto the material carrier shaft  560  and conical portion  562 , preferably in the manner described below, and its free or second end is fed into the outlet of the body portion  510 , that is into the lumen leading to the luer fitting  520 . 
         [0082]    In use, fluid is pumped into the chamber of the receptacle  500  via the inlet luer fitting  558 , for example by means of a syringe, whereupon it passes through the lumen  570  of the material carrier  550 . The chamber of the receptacle  500  will fill with fluid, enveloping the filamentary material wound on the carrier shaft  560  and cone  562 , which will make it easier to unwind. The pumped fluid will also pass into the outlet  520 , particularly once the chamber has filled with fluid so as to increase pressure in the chamber, and in practice into a delivery catheter attached to the luer fitting  520 . This flow of fluid will pull the filamentary material with it, thereby to deliver the filamentary material through the catheter and into the patient. 
         [0083]      FIGS. 14 and 15  show the surface of the material carrier  550 , that is of the conical portion  562  and the cylindrical shaft portion  560  being stepped. In other embodiments, these surfaces could be smooth. 
         [0084]    The lumen  570 , which is generally aligned with the outlet  520 , also provides a flow of driving fluid directly into the outlet  520  and therefrom into an attached catheter, which contributes to an increased filament driving force. 
         [0085]    It is to be understood that the embodiments of  FIGS. 3 to 7  could have a material carrier with a lumen extending along its length similar to the embodiments of  FIGS. 8 to 14 , and similarly the embodiments of  FIGS. 8 to 15  could have driving fluid conduits and apertures exiting laterally adjacent the distal end of the material carrier in manner similar to the embodiments of  FIGS. 3 to 7 . 
         [0086]      FIGS. 16A to 16C  show a preferred embodiment of winding process for winding filamentary material, or thread, onto the material carrier. The method depicted and disclosed herein is suitable for all embodiments disclosed herein and covered by the scope of the claims. 
         [0087]    Referring first to  FIG. 16A , this shows in schematic form a material carrier  600  similar to that of the embodiment of  FIGS. 8 to 11 , although it could be any other material carrier including a conical carrier of the type shown in  FIGS. 3 to 5  or part conical carrier of the type shown in  FIGS. 14 and 15 . In the example shown, the material carrier  600  includes a receptacle fixing or cover element  610  for attachment to the body portion of a receptacle (not shown) and a shaft  620  which in this embodiment has a lumen (not shown) passing throughout its length and exiting at the tip  630 . 
         [0088]    Filamentary material  650  is wound onto the shaft  620  commencing from its distal end  640 , by rotating the material carrier  600  in the direction of the arrow  660 . In the first instance, a few turns of material  650  are wound at the distal end  640  and then the material feed  670  is moved slightly forwards, towards the proximal end  630  of the shaft  620 , by a given amount. So doing creates a conical layer of material  650 . The material feed  670  is reciprocated backwards and forwards to form a series of conical layers of material  650 , winding over the first turns, and once the desired diameter of wound material  650  is reached at the distal most position on the shaft  620 , the material feed  670  is moved proximally by a given distance, that is towards the proximal end  630 , typically equivalent to around one or more thread widths, to wind another conical layer of material  650  over the conical base already formed. The material feed  670  is moved gradually towards the proximal end  630  in stages while reciprocating backwards and forwards by a given distance, so as to create a series of overlapping conical layers of material  650  extending towards the proximal end  630 , as can be seen in the sequence shown in  FIGS. 16A to 16C . The conical layers of material  650  will in practice be distinct from one another in terms of winding sequence. As a result, when the material  650  is made to unwind from the carrier  600  it will do so one conical section at a time. Thus only the proximal most portion of filamentary material  650  or thread will unwind, even though there are in practice many layers of material  650  carried on the carrier  600 . When the first conical layer has been unwound, the next in the series will unwind. This arrangement can prevent unwinding from outer layers distal of the proximal end of the winding, which can cause turns of material to become embedded in underlying layers during the unwinding process. Any such embedding of the thread, as can occur in prior art arrangements, can lead to increased resistance to unwinding and at worst blockage of the thread on the carrier  600 . Similarly, this arrangement can ensure that no turns of thread uncouple prematurely from the shaft  620 . 
         [0089]    The material feed  670  could be any suitable element, including a movable feed nozzle or guide attached to a material supply. Control of the material feed could be mechanical and/or electronic as desired. 
         [0090]    It will be appreciated that the thread  650  will be pulled from the distal end  630  in a direction precisely parallel or substantially parallel to the axis of the shaft  620  in the embodiments disclosed herein. 
         [0091]    Referring now to  FIGS. 17A to 17C , these show in schematic form a catheter  12  in transverse cross-section with one or more filaments of bio absorbable material  24  held therein. The current goal of the device is to introduce bioabsorbable material in the form of a filament into the cavity of an aneurysm. It is postulated that the material will initially create an embolic reaction within the cavity of the aneurysm, before acting as a scaffold to engender cellular growth. The filament  24  itself is constrained in size to fit within the lumen of the catheter  12  to enable delivery. When coming into contact with the blood, cells will permeate the material  24  and the expectation is that the material will remodel over time into natural tissue. If sized correctly, it is possible to introduce more than one filament at the same time through the lumen of the catheter  12 . The introduction of multi-filaments instead of a single filament, as shown in  FIGS. 17B and 17C  would aid the following: 
         [0092]    1) increased contact (surface area) between the filament and the blood to aid thrombogenicity; 
         [0093]    2) slight separation of the filaments upon exiting the aneurysm may help distribute the material evenly; 
         [0094]    3) less fluid required to deliver the filament in longer lengths, albeit in smaller volumes; 
         [0095]    4) it will also be appreciated that in the embodiments disclosed, the material is wound onto a carrier which is substantially aligned with the longitudinal axis of the dispenser and of the apparatus itself. In practice, the long axis of the material carrier is at least roughly in the dispensing direction of the assembly. 
         [0096]    In the preferred embodiments, the carrier element is precisely aligned with the dispensing direction of the receptacle. In other embodiments, the carrier element may be disposed at an angle to the dispensing direction of the receptacle. In such embodiments, the carrier will have a side relatively remote from the outlet of the receptacle and thus to the dispensing direction. This angle is advantageously no more than around 30 degrees relative to the dispensing direction, in practice the longitudinal axis of the receptacle as determined by the direction of movement of the fibre out of the outlet. More suitably, this angle is less than around 20 degrees and even more suitably less than around 10 degrees. In practice, the angle should preferably be less than around 5 degrees. It will be appreciated that in embodiments having a cylindrical carrier element, both the closer and the remote side of the carrier when in the angled disposition will be at the same angle to the dispensing direction. On the other hand, in cases where the carrier is not cylindrical, for instance is conical as shown in some embodiments, the side of the carrier closer to the outlet may be at a greater angle than that of the side remote from the outlet. The term “substantially aligned” as used herein in relation to the relationship of the carrier relative to the dispensing direction is therefore to be understood to encompass one of these preferred ranges, as well as an arrangement in which the carrier is precisely aligned with the dispensing direction. 
         [0097]    The delivery systems taught herein functions when a fluid is introduced within the catheter  12  dragging the filament  24  along its lumen. A small but minimum fluid velocity is required to generate enough friction to drag the filament  24 , thereby making the applied force by the user (for example with a syringe) a relevant element in its operation. While no patient risk is perceived by applying a force too small to enable the system to work, the function of the pressure valve will enhance the system as: 
         [0098]    1) it will prevent the user from introducing excess liquid into the aneurysm without any advancement of the material; 
         [0099]    2) it will provide tactile feedback to the user as the valve will prevent liquid from exiting the syringe without the application of a minimum force, giving the user ‘feel’ when operating the device. 
         [0100]    An example of a minimum pressure valve arrangement is shown in  FIGS. 18A to 20B , in which it can be seen that a valve  55  is disposed at the inlet to the receptacle  30 . The valve  55  itself can be made from any suitable material, such as a polymer or rubber. Silicone is a particularly suitable material due to its mechanical properties. 
         [0101]    As depicted in the Figures, the optimal shape of the valve  55  is a dome which is split into a number of leaves or elements  57  (four leaves in this example), and a disc  59  at the base which functions as an anchor to fix the valve  55  within the receptacle  30 . 
         [0102]      FIGS. 18B ,  20 A and  20 B show the valve  55  when sufficient fluid force is applied. The capacity of the valve  55  to open will be determined by the choice of material and wall thickness. The valve  55  will return to its natural closed position, as seen in  FIGS. 18A ,  19 A and  19 B, when the force applied (by the syringe) becomes too small to keep the leaves  57  open. 
         [0103]    The valve  55  is preferably positioned at the proximal end of the receptacle, between the syringe connection and the main chamber. 
         [0104]    In the embodiments described the filamentary material is fed through a catheter into the patient. It is to be understood that the teachings herein are not limited to a specific deliver device and could be used with any tubular delivery device including a catheter, cannula or needle. 
         [0105]    All optional and preferred features and modifications of the described embodiments and dependent claims are usable in all aspects of the invention taught herein. Furthermore, the individual features of the dependent claims, as well as all optional and preferred features and modifications of the described embodiments are combinable and interchangeable with one another.