WO2005063330A1

WO2005063330A1 - Catheter duct and method for bleeding it

Info

Publication number: WO2005063330A1
Application number: PCT/IT2003/000874
Authority: WO
Inventors: Andrea Venturelli
Original assignee: Invatec S.R.L.
Priority date: 2003-12-30
Filing date: 2003-12-30
Publication date: 2005-07-14
Also published as: AU2003300762A1

Abstract

The invention relates to a duct for feeding the inflation fluid to a balloon in a catheter for endoluminal interventions. The duct comprises a tubular body, at the distal end of which there are inflation and deflation apertures in communication with the balloon. At the proximal end of the tubular body there are a non-return valve and reconfigurable means for arranging alternatively the opening or closure. The first of the lumina is in communication with the non-return valve and with the inflation aperture, while the second of the lumina is in communication with said deflation aperture and with said reconfigurable means. The invention also relates to a method for bleeding such a duct.

Description

"CATHETER DUCT AND METHOD FOR BLEEDING IT"

The present invention relates to a duct for feeding the inflation fluid to a balloon in a catheter for endoluminal interventions. The present invention further relates to a system and a catheter which comprise such a duct . Finally, the present invention relates to a method for bleeding such a system. As is known, many of the catheters for endoluminal interventions have, in proximity to their distal end, one or more balloons which can be brought from a restricted state to an expanded state and vice versa, by means of the introduction or aspiration of an inflation fluid. From a purely conceptual point of view, such an inflation fluid could consist of air, but the risk of a leak occurring on the balloon or at any other point in the duct does not make the use of air advisable . The introduction of gas bubbles into the blood vessels is in fact potentially very dangerous and may have very serious consequences for the patient. For this reason the inflation fluid generally consists of an aqueous solution; as a rule of a physiological solution. Before starting to operate on the patient, the operator must therefore bleed the balloon and the duct for feeding the inflation fluid, that is to say, must ensure that they are full of aqueous solution and that there are no residual air bubbles therein. To carry out this bleeding, the operator normally places the catheter in a position such that the proximal end of the feed duct is positioned higher than all the rest of the duct . In this way, following the introduction of the aqueous solution, the latter tends to occupy by gravity the lowest regions of the duct, displacing the air towards the highest region, that is to say, towards the proximal end, from which it is removed. This known bleeding method is not, however, devoid of drawbacks. It is in fact possible that, notwithstanding the care taken by the operator, the practical conditions in which bleeding must be completed do not permit the proximal end to be effectively placed higher than all the other sections of the duct . It is moreover possible that, as a result of surface adhesion phenomena, air bubbles may remain clinging to the walls of the balloon or of the duct and that the force of gravity which acts on the aqueous solution is not sufficient to remove them. With this method, therefore, it is not possible to guarantee adequate bleeding of the air present in the duct. The problem underlying the following invention is that of devising a duct and a method for bleeding it which make it possible to remedy the drawbacks mentioned with reference to the prior art . This problem is solved by a duct according to claim 1, by a system according to • claim 25 and by a catheter according to claim 27. The problem is also solved by a method for bleeding the system according to claim 34. Further characteristics and advantages of the duct and of the method according to the invention will become clear from the following description of a preferred exemplary embodiment, provided by way of non-limiting example, with reference to the appended drawings, in which: Figure 1 shows an overall view, partly in section, of a catheter comprising a duct according to a first embodiment of the invention; Figure la shows a perspective view of a detail of Figure 1 ; Figure 2 shows a view, partly in section, of a system comprising a duct similar to that in Figure 1; Figure 2a shows a view in section of a detail of Figure 2; Figure 3 shows a perspective view, partly in section, of a system comprising a duct according to a second embodiment of the invention; Figure 4 shows an overall view, partly in section, of a catheter comprising a duct similar to that in Figure 3; Figures 5a, 5b and 5c show possible embodiments of the section along the line V-V in Figure 3 ; Figures 6a, 6b, 6c and 6d show possible embodiments of the section along the line VI-VI in Figure 4; Figure 7 shows in the form of a block diagram a form of the method according to the invention; Figures 8a, 8b, 8c, 8d and 8e show, diagrammatically, successive steps of the bleeding method according to an embodiment of the invention. With reference to the appended drawings, a description will now be given of the duct according to the invention, indicated as a whole by 1, and the method for bleeding it, also according to the invention. The duct 1 comprises a tubular body 3 which comprises at least two lumina 100 and 101. At the distal end of the tubular body at least one inflation aperture 7 ' and one deflation aperture 7" are provided which can be placed in communication with the inside of the balloon 10. According to a particular embodiment, the inflation aperture 7¹ and the deflation aperture 7" coincide. At its proximal end, the tubular body 3 assumes instead a Y-shape to the two free branches of which are respectively connected a non-return valve and reconfigurable means capable of assuming an open configuration in order to obtain at least partial opening or, when required and as an alternative, a closed configuration for obtaining the sealed closure of the branch. According to the preferred embodiment shown in the appended Figures 1 and 2, the first lumen 100 of the tubular body 3 is connected to the first of the three branches of a Y-shaped connector 2. Such a connection guarantees the sealing of the duct 1 and its fluid continuity. The second branch of the Y-shaped connector 2 comprises a non-return valve 4, which is known per se, positioned so as to permit the introduction of fluids into the first lumen 100 and at the same time prevent the escape thereof . The third branch of the Y-shaped connector 2 comprises reconfigurable means suitable for obtaining at least partial opening or, when required, sealed closure of the branch to which they belong. According to a preferred embodiment, the reconfigurable means comprise a tap 50. According to another embodiment, shown in Figures 1 and 2, the reconfigurable means comprise a self-occluding insert 5. The self-occluding insert 5 assumes, for example, the form of a plug or of one or more membranes which hermetically seal the branch of the duct on which they are fixed. It furthermore permits the introduction of a foreign body such as, for example, a pin or needle. If the foreign body has a suitable cross-section, for example similar to that of a hollow needle of the type used for syringes, its introduction effects the partial opening of the branch. Finally, the self-occluding insert 5 is capable, following the removal of the foreign body, of constituting a closure member, that is to say, for restoring the hermetic seal of the closure. The self-occluding insert 5 is preferably made of an extremely elastic material, particularly an elastomer.

Even more preferably, the self-occluding insert 5 is produced by means of a latex plug. According to a preferred embodiment, the duct 1 comprises, at least near the reconfigurable means and at least if the latter are in an open configuration, a narrowing in cross-section, or a necking or a clear reduction of the cross-section of the duct. In the case where the reconfigurable means comprise a tap 50, the narrowing may be determined by the actual geometry of the mechanism of the tap or by only partial opening thereof . In the case where the reconfigurable means comprise a self-occluding insert 5, the narrowing is preferably determined by the foreign body introduced into the insert itself. The first lumen 100, delimited by a first tubular member or tube 102, places the non-return valve 4 and the inflation aperture 7¹ in communication, while the second lumen 101, delimited by a second tubular member or tube 103, places the deflation aperture 7" and the reconfigurable means in communication. The first lumen 100 and second lumen 101 are separated for almost their entire length and communicate with one another only near the inflation aperture 7 ' and deflation aperture 7". With reference to the preferred embodiment shown in Figures 1, 2 and 2a, the second tube 103 or venting tube 6 has an outside diameter smaller than the inside diameter of the first tube 102, is housed therein, and extends through the entire length thereof . The distal end of the venting tube 6 is located in proximity to the inflation aperture 7' and the proximal end passes through the self- occluding latex insert 5 and ends with a Luer connector 8 of known type. According to one embodiment, the Luer connector 8 also comprises a removable plug 8 ' . In this embodiment, the space comprised between the inside diameter of the duct 1 and the outside diameter of the venting tube 6, and which extends from the non-return valve 4 to the inflation aperture 7 ' , constitutes the first lumen 100 of the duct. The lumen within the venting tube itself, which extends substantially for the entire length of the duct 1, on the other hand constitutes the second lumen 102. The deflation aperture 7", which coincides with the cross-section of the venting tube 6, in this embodiment constitutes the narrowing. According to another embodiment, the tubular duct 30 has a figure-8 cross-section in which the two lumina 100 and 101 are separated. In this embodiment the non-return valve 4 is connected to the proximal end of the first lumen 100, and to the proximal end of the second lumen 101 are connected the reconfigurable means capable of alternatively effecting at least partial opening or sealed closure thereof. The second lumen 101 also comprises, in proximity to the reconfigurable means, the narrowing in cross-section. The reconfigurable means may comprise, for example, a tap 50 or a self-occluding insert 5 of the type described above . Similarly, any narrowing of the cross-section that may be present near the reconfigurable means if the latter are in an open configuration, may be determined by the mechanism of the tap 50 or may be determined by the cross- section of the foreign body inserted into the self- occluding insert 5. The two lumina of the tubular body 30 are placed in communication with one another preferably only near the inflation aperture 7' and deflation aperture 7". Another feature of the present invention relates to a system 60 constituted by a balloon 10 in fluid communication with a duct 1 of the type described above for feeding the inflation fluid 12 to such a balloon 10. Such fluid communication is preferably sealed. A further feature of the present invention relates to a catheter 70 for endoluminal interventions which comprises at least one balloon 10 and at least one duct 1 of the type described above for feeding the inflation fluid 12 to the balloon 10. In a particular embodiment, the catheter 70 is a catheter for carrying out angioplasty interventions and comprises at least one balloon intended for widening a stenosis. In another embodiment, the catheter 70 is a catheter for positioning stents and comprises at least one balloon intended to give the final shape to the stent itself. In further embodiments, the catheter 70 comprises at least one balloon for the temporary occlusion of blood vessels. The method for bleeding the system 60 described above comprises the following actions . Configuring said reconfigurable means 5 or 50 so as to arrange the opening thereof . Feeding the inflation fluid 12 to the duct 1 through the non-return valve 4, so as to force the inflation fluid 12 along the first lumen 100, inside the balloon 10 and along the second lumen 101. Causing the inflation fluid 12 to flow out of the proximal end of the second lumen 101. According to an embodiment of the method, a quantity of inflation fluid 12 is prepared, for example physiological solution, in an amount greater than the capacity of the duct 1. The inflation fluid 12 is arranged in a pumping system 9 suitable for connection to the non-return valve 4, for example a syringe. The pumping system 9 is then connected to the non-return valve 4. According to a particular embodiment of the method, before feeding the fluid 12 to the duct 1, a constriction system 12 is arranged round the balloon 10. This constriction system may preferably consist of a suitable tubular cap 11 which also serves as protection for the balloon 10 in case of any contacts which may accidentally occur in the preparatory steps of the intervention. If such contacts are rather violent or occur with sharp-edged or pointed objects, the balloon 10 may be severely damaged and become unusable; for this reason, a tubular cap 11, for example, is used which protects the balloon and which must be removed immediately before the insertion of the catheter 70. In place of the tubular cap 11, the system for constriction of the balloon 10 may be obtained by the operator in any other manner which proves suited to the circumstances, for example, by squeezing in the hand the distal end of the duct 1 and with it the balloon 10. The pressure applied by the pumping system 9 forces the inflation fluid 12 to flow through and to occupy first of all the first lumen 100 of the duct 1, for example the space comprised between the inner wall of the first tube 102 and the outer wall of the venting tube 6 or, alternatively, the first lumen 100 delimited by the first tube 102 of the tubular body 30 of figure-8 cross-section. Then the inflation fluid 12, through the inflation aperture 7', fills the balloon 10 which, for example, is constrained into its restricted state by the constriction system 11. When all the space within the balloon 10 is occupied by the inflation fluid 12, the latter, through the deflation aperture 7", begins to re-ascend along the second lumen 101 of the duct 1, defined for example by the venting tube 6 or by the second tube 103 of the tubular body 30. It is necessary at this point to wait for the inflation fluid 12 to emerge from the proximal end of the duct 1, through the reconfigurable means. It may initially emerge discontinuously or irregularly, owing to the presence of the last air bubbles. It is then necessary to wait until the outflow of the inflation fluid 12 is regular. It is possible at this point to interrupt the feeding of the inflation fluid 12 to the duct 1, for example by interrupting the actuation of the pumping system 9. At this point, bleeding has been completed in the best possible manner. The obligatory path taken by the inflation fluid 12 has in fact forced all the air previously present inside the tubular body 3 and the balloon 10 to flow out. The presence of the narrowing further implies that the feeding of the inflation fluid 12 must take place at a rather high pressure so that the fluid itself may re- ascend in the duct and flow out of it. Such a pressure further guarantees the removal of all the air bubbles from inside the duct 1. To proceed further, the operator may at this point act on the reconfigurable means to bring them into the closed configuration, for example by closing the tap 50 or by fitting a plug 8 ' to the Luer connector 8 and by withdrawing the venting tube 6 through the self-occluding insert 5. The self-occluding insert in fact makes it possible for the small hole through which the venting tube 6 passed to close again, ensuring the sealing of the duct 1. If the venting tube 6 is not withdrawn, the endoluminal intervention may proceed just the same, provided that the proximal end of the venting tube itself is also closed off, for example by means of the plug 8¹. In this case, however, the flexibility of the duct will be uselessly limited by the presence of the venting tube 6. Before proceeding with the endoluminal intervention, it is still necessary to remove, if it has been employed, the constriction system, typically the tubular cap 11, so that subsequent actuation of the pumping system 9 effectively inflates the balloon 10. In order to reduce the risk of the tubular cap 11 being left in position accidentally, it may include high visibility inserts 13, for example of clearly distinguishable colours, different from those of the rest of the system 60. The duct 1, the system 60 composed of the duct 1 and a balloon 10, and the method for bleeding such a system 60 according to the invention are thus described. A duct 1, a system 60 and a method of this type make it possible to respond perfectly to the necessary structural and functional requirements. Such a method further makes it possible to obtain great advantages over the known bleeding methods, since it guarantees the forced removal of any possible air bubble. As will be realised from what has been described above, the duct and the method for bleeding it according to the invention make it possible to satisfy the aforesaid requirements and at the same time to remedy the drawbacks referred to in the introduction of the description.

Claims

CLAIMS 1. A duct (1) for feeding the inflation fluid (12) to a balloon (10) in a catheter (70) for endoluminal interventions, comprising: - at least one tubular body (3, 30) comprising at least two lumina (100, 101) ; at the distal end of said tubular body (3, 30), at least one inflation aperture (7') and at least one deflation aperture (7"), capable of being placed in fluid communication with said balloon (10) ; and at the proximal end of said tubular body, a nonreturn valve (4) and reconfigurable means (5, 50) capable of arranging alternatively an opening or a closure member; a first of said lumina being in fluid communication with said non-return valve (4) and with said inflation aperture (7 ' ) ; and a second of said lumina being in communication with said deflation aperture (7") and with said reconfigurable means (5, 50) . 2. A duct according to claim 1, wherein said first lumen (100) and said second lumen (101) are in fluid communication with one another only near said inflation aperture (7¹) and deflation aperture (7"). 3. A duct according to claim 1 or claim 2 , wherein said inflation aperture (7') and said deflation aperture ( 7 " ) coincide . 4. A duct according to any one of the preceding claims in which said at least one tubular body (3, 30) comprises a first tube (102) • comprising said first lumen (100) . 5. A duct according to any one of the preceding claims in which said at least one tubular body (3, 30) comprises a second tube (103) comprising said second lumen (101) . 6. A duct according to any one of the preceding claims, wherein said non-return valve (4) is positioned so as to permit the introduction of fluids into said duct (1) and at the same time prevent the escape thereof . 7. A duct according to any one of the preceding claims, wherein said reconfigurable means comprise a self- occluding insert (5) capable of being urged by a foreign body to delimit said opening or to provide said closure member on withdrawal of said foreign body. 8. A duct according to claim 7, wherein said self- occluding insert (5) is made of elastomeric material. 9. A duct according to claim 7, wherein said self- occluding insert (5) is a latex plug. 10. A duct according to any one of claims 7 to 9, wherein said foreign body is a hollow needle. 11. A duct according to any one of claims 1 to 6, wherein said reconfigurable means comprise a tap (50) . 12. A duct according to any one of the preceding claims, wherein said tubular body (30) comprises at least two tubular members (102, 103) which define said at least two separate lumina (100, 101) . 13. A duct according to claim 12 , wherein said at least two tubular members (102, 103) are produced in one piece. 14. A duct according to any one of the preceding claims, wherein said tubular body (30) comprises a single tubular member which delimits at least 2 lumina. 15. A duct according to claim 12, wherein the proximal end of a first tube (102) of said tubular body

(30) is connected to said non-return valve (4) and the proximal end of a second tube (103) of said tubular body (30) is connected to said reconfigurable means (5, 50) . 16. A duct according to any one of claims 1 to 11, comprising a venting tube (60) disposed inside said tubular body (3) . 17. A duct according to claim 16, wherein said venting tube (6) is capable of urging said reconfigurable means so as to delimit an opening. 18. A duct according to claim 15, where said first lumen (100) is delimited by the inside diameter of said tubular body (102) and the outside diameter of said venting tube (6) , and said second lumen (101) is delimited by the inside diameter of said venting tube (6) . 19. A duct according to any one of the preceding claims, wherein said non-return valve (4) is capable of being placed in fluid communication with a pumping system (9) . 20. A duct according to any one of the preceding claims, wherein said non-return valve (4) is capable of being placed in fluid communication with a syringe (9) . 21. A duct according to any one of the preceding claims, wherein said first and second lumina (100, 101) constitute a flow path comprising a narrowing capable of effecting a variation in the pressure of the fluid. 22. A duct according to claim 21, wherein said narrowing is provided in proximity to the deflation aperture (7" ) . 23. A duct according to claim 21, wherein said narrowing is provided in proximity to the self-occluding insert (5) . 2 . A duct according to claim 21, wherein said narrowing is produced by means of partial occlusion of the tap (50) . 25. A system (60) comprising a balloon (10) in fluid communication with a duct (1) according to any one of the preceding claims.

26. A system (60) according to claim 25, wherein said fluid communication is obtained by means of a sealed connection. 27. A catheter (70) for endoluminal interventions, comprising a duct according to any one of claims 1 to 24. 28. A catheter (70) according to claim 27, further comprising a balloon (10) . 29. A catheter (70) according to claim 28, wherein said duct (1) is in fluid communication with said balloon (10) . 30. A catheter (70) according to claim 29, wherein said fluid communication is obtained by means of a sealed connection. 31. A catheter (70) according to any one of claims 28 to 30, further comprising a constriction system (11) removably arranged round said balloon (10) . 32. A catheter (70) according to claim 31, wherein said constriction system (11) comprises a tubular cap. 33. A catheter (70) according to claim 31, wherein said constriction system (11) includes high visibility inserts. 34. A method for bleeding a system according to claim 25, comprising the steps of: configuring said reconfigurable means (5, 50) so as to arrange an opening; feeding inflation fluid (12) to the duct through the non-return valve (4) , so as to force said inflation fluid along said first lumen (100) , inside said balloon (10) and along said second lumen (101) ; - causing said inflation fluid (12) to emerge from the proximal end of said second lumen. 35. A method' according to claim 34, further comprising the step of configuring said reconfigurable means (5, 50) so as to obtain a closed configuration. 36. A method according to claim 35, wherein said step of configuring said reconfigurable means (5) comprises the action of removing a foreign body from a self-occluding insert. 37. A method according to claim 36, wherein said step of removing the foreign body comprises the action of completely withdrawing the venting tube (6) from the self- occluding insert (5) . 38. A method according to claim 37, comprising the action of occluding said venting tube (6) before withdrawing it from the self-occluding insert (5) . 39. A method according to claim 35, wherein said step of configuring said reconfigurable means (50) comprises the action of closing a tap (50) . 40. A method according to claim 34, further comprising, before said step of feeding the inflation fluid (12) , the step of arranging a constriction system (11) round said balloon (10) . 41. A method according to claim 40, further comprising the step of removing said constriction system (11) .