VALVE COMPONENT AND VALVE ARRANGEMENT

Description

[0001] The present invention relates to a valve component and a valve assembly for use in medical applications, and more particularly to a haemostatic valve assembly for use in medical procedures with vascular introducer sheaths, catheters and the like.

[0002] In this connection, haemostatic valves are used to prevent fluid from inadvertently leaving or entering a body target site, and generally comprise a housing defining a passage there-through adapted to receive an elongated medical instrument such as a catheter in a haemostatic sealed condition.

[0003] Valves of this nature are used in a wide variety of surgical procedures and such procedures are becoming increasingly complex, including multiple exchanges of guidewires, catheters, and delivery systems.

[0004] Current haemostatic valves generally fall into two basic categories: passive and active. To form the desired fluid tight seal, a passive valve generally relies on a resilient sealing body being deformed by the medical instrument as it is inserted through the valve. An active valve in contrast includes a means requiring activation by a user, typically a surgeon, to move a sealing body into contact with the traversing medical instrument in question.

[0005] A wide variety of passive haemostatic valves have been proposed in the past and a common issue with these is that in order to achieve a reliable seal that will continue to seal without leakage despite such multiple exchanges, the entry force and friction to movement on entry and exit of the catheter becomes excessive, potentially damaging the instruments being used, and causing injury to the patient.

[0006] Active valves deal with this issue by including mechanisms by which the tightness of the sealing components can be relaxed on entry and exit. Such valves have the disadvantage though that they are more complicated and expensive to manufacture and require an extra operational step for the medical staff to perform, this slowing down the procedure and requiring additional expertise.

[0007] US4798594 discloses an elastomeric seal with a slit through the seal.

[0008] WO94 / 22357 discloses a seal with an expandable passage in the form of a slit with means to manually compress to alter the seal.

[0009] US2005 / 171479 discloses a seal that has rotation means to selectively constrict the longitudinal opening.

[0010] An object of the present invention is to alleviate problems associated with known valves.

[0011] The invention is as defined in the claims.

[0012] According to the present invention there is provided a valve component for a medical valve assembly, the valve component comprising: a deformable body and a valve assembly housing, wherein the deformable body is for location in the valve assembly housing, the deformable body comprising a conduit for receiving one or more medical instruments there-through, one or more helical grooves being formed on a surface of the conduit, the one or more helical grooves extending into the deformable body from the conduit surface, wherein the valve assembly housing is adapted to put the deformable body into a compressed state and wherein the walls of the valve assembly housing are tapered to allow variable compression of the deformable body on movement of the deformable body within the housing. In this way, the valve component affords a more reliable sealing arrangement with relatively low insertion forces for medical instruments used therewith.

[0013] Preferably, the conduit extends from a proximal end of the body to a distal end of the body, the one or more helical grooves extending into said deformable body from the conduit surface to define one or more helical contact surfaces for contacting one or more medical instruments located in the conduit. In use, such helical contact surfaces are biased into contact with the one or more medical instruments located in the conduit. The inclination of the helical grooves around the axis of the conduit is such as to lead to closure of voids in the grooves on a longitudinal compression resulting from insertion of the one or more medical instruments. This enhances the sealing of the flow path within the deformable body.

[0014] Conveniently, a plurality of helical grooves is provided on the conduit surface. Preferably, three helical grooves are provided on the conduit surface. The provision of three grooves has been found to show particularly enhanced sealing properties.

[0015] In preferred embodiments, the deformable material has a shore hardness 'A' of 5 to 20. Such a shore hardness parameter offers a beneficial degree of resilience.

[0016] Preferably, the valve component is for use in a haemostatic valve.

[0017] Conveniently, the pitch of one or more of said one or more helical grooves is in the range 2 to 10 mm. Such a pitch affords enhanced sealing properties.

[0018] The helical vane diameter of the one or more helical grooves is preferably in the range 2 to 10 mm. Such a vane diameter provides enhanced sealing properties and allows ease of access through the conduit.

[0019] The invention provides a valve assembly comprising a valve component as defined above, and a valve assembly housing, wherein the housing is adapted to put the deformable body into a compressed state. Simple oversizing of the deformable body with respect to the housing sets up a suitable bias within the body to close voids and prevent leakage.

[0020] Preferably, the deformable body has outer dimensions oversized by 1 to 15% in relation to the internal body retaining dimensions of the housing. Conveniently, the body and housing are each cylindrical, with the external diameter of the body being 1 to 15% greater than the internal diameter of the housing.

[0021] The deformable body may be a first deformable body, a second deformable body being provided having a conduit for receiving said one or more medical instruments there-though, the conduits of the first and second deformable bodies having a common axis. The second deformable body acts to further enhance sealing of the assembly and assist in guiding the one or more medical instruments into the first deformable body.

[0022] Preferably, the conduit of the second deformable body has a widened opening at an introduction end for facilitating introduction of said one or more medical instruments. The opening may have tapered sides and may, for example, have a bowl-like guide surface for assisting the user in readily and reliably introducing one or more medical instruments into the valve assembly.

[0023] Conveniently, the first and second deformable bodies abut one other within the housing, with their conduits aligned along a common axis.

[0024] The walls of the valve assembly housing and the first deformable body are tapered to allow variable compression of the deformable body on movement of the deformable body within the housing. In this manner, the sealing properties can be refined if required.

[0025] Conveniently, the valve assembly further comprises a purse string suture for opening and closing the valve. As such, the sealing properties of the deformable body can be manipulated if required.

[0026] Certain preferred embodiments of the present invention will now be described by way of example and with reference to Figures 1 to 8 of the drawings, of which:- Figure 1 shows in a sectional view of a valve assembly having a valve component of the present invention; Figure 2 shows an exploded view of the valve assembly components of Figure 1; Figure 3 shows a part cross-sectional view of the valve assembly of Figures 1 and 2; Figure 4 shows a perspective view of a triple helix core corresponding to triple helix grooves provided around a conduit in a deformable body of the present invention of Figures 1 to 3; Figures 5A, 5B and 5C show single, double and triple helix variants of the present invention; Figure 6 shows a schematic view of the forces at play on insertion of one or more medical instruments with the valve component of the present invention; Figure 7 shows a variant of a valve assembly having a valve component according to a further embodiment of the present invention; and Figure 8 shows a variant of a tapered valve body according to a further embodiment of the present invention.

[0027] The present invention relates to valves for use in medical applications and more particularly to haemostatic valves used in endovascular procedures.

[0028] In this connection and as shown in Figures 1 to 3, the invention concerns a first deformable body 1 retained within a housing 2 that also preferably houses a second deformable body 3. The first and second deformable bodies may be oversized with respect to the housing so that when inserted within the housing they are in a state of compression. In this regard, the housing comprises a cylindrical body section for retaining the first and second deformable bodies, the diameters of the bodies being oversized by 1 to 15 % with regard to the diameter of the cylindrical body section. The deformable bodies are formed of liquid moulded silicon, although any suitable alternative compliant materials, such as rubber, may be used.

[0029] An end cap 4 threadingly engages an open end of the housing 2 to close off the assembly 10 formed by the housing, deformable bodies and end cap.

[0030] The end cap 4 has an aperture 5 allowing access of one or more medical instruments, such as a catheter (not shown) into the housing. An opposite end of the housing has a similar opening 6 allowing the one or more medical instruments to pass through the assembly, into for example an introducer sheath mounted at this end of the housing.

[0031] As shown in Figure 3, the two deformable bodies 1, 3 each have a preformed conduit 7, 8, the conduits being aligned with the axis passing through apertures 5, 6. The conduits 7, 8 have a cross-section that is dimensioned to be slightly undersized with respect to the cross-section of the medical instrument to be used with the assembly so that the deformable bodies seal around the one or more medical instruments when pushed through the assembly. A typical needle valve might have a diameter of 1.2 mm such that the conduit diameter would be marginally less. Of course, the dimensions of the valve components may be varied to suit the requirements of the instruments with which they are being used.

[0032] The first deformable body 1 has one or more helical grooves 9 formed in the conduit surface defining helical contact surfaces 16 for engaging longitudinally along the one or more medical instruments passing through the assembly. The one or more helical grooves are preformed into the material of the first deformable body. The one or more helical grooves may have a helical vane diameter in the range of 2 to 10 mm. In certain preferred embodiments, the one or more helical grooves extend to a diameter of up to 6 mm or more preferably 5.6 mm about the central axis of the conduit through the deformable body. The one or more helical grooves moreover extend longitudinally along a major portion of the first deformable body.

[0033] As shown in Figure 6, the inclination resulting from the helix configuration of the one or more grooves 9 means that on insertion of the one or more medical instruments, a longitudinal compression is applied to the first deformable body 1, which causes helical voids and gaps to close, therefore sealing the flow path through the valve assembly.

[0034] In this regard, the pitch of the helical grooves is preferably in the range of 2 to 10 mm, and more preferably 3 mm.

[0035] In certain preferred embodiments, the helical vane diameter is in the range 2 to 10 mm and more preferably 5.6 mm.

[0036] In the preferred embodiments, three helical grooves are provided, as shown in Figures 4 and 5A. Each of said grooves preferably has a helical vane diameter in the range of 2 to 10 mm and preferably 5.6 mm and a pitch in the range of 2 to 10 mm and preferably 3 mm.

[0037] Figures 5A, 5B and 5C in this respect show triple, double and single helix variants.

[0038] The one or more helical grooves may have a width of 0.8mm to 2.0mm.

[0039] It is intended that one size of the valve assembly can offer sealing from wire entry up to a 23Fr OD Anaconda (RTM) delivery sheath.

[0040] Whilst the above described valve assembly incorporates a passive valve component, in certain circumstances, it may be necessary to refine the sealing properties of the assembly, for example for a surgeon to control back flow leakage. Figure 7 shows a variant of a valve component according to a further embodiment of the present invention where the deformable body 1 has a purse string sealing arrangement to enable refinement of the sealing properties of the assembly.

[0041] Figure 8 shows a further variant of a valve assembly where the inward facing walls 11 of the housing are tapered, as are the outer surface walls of the first deformable body 1. In this way, by moving the first deformable body relative to the walls 11, the strength of compression of the deformable body 1 can be increased and decreased, thereby varying the sealing properties of the assembly.

[0042] In preferred embodiments, the enhanced sealing properties afforded by the valve assembly allow it to accommodate multiple catheter insertions simultaneously.

Claims

1. A valve component for a medical valve assembly, the valve component comprising: a deformable body (1) and a valve assembly housing (2), wherein the deformable body (1) is for location in the valve assembly housing (2), the deformable body (1) comprising a conduit (5) for receiving one or more medical instruments there-through, one or more helical grooves (9) being formed on a surface of the conduit (5), the one or more helical grooves (9) extending into the deformable body (1) from the conduit surface; characterised in that the valve assembly housing (2) is adapted to put the deformable body (1) into a compressed state and wherein the walls of the valve assembly housing (2) are tapered to allow variable compression of the deformable body (1) on movement of the deformable body (1) within the housing (2).

2. A valve component as claimed in claim 1, wherein the conduit (5) extends from a proximal end of the body (1) to a distal end of the body (1), the one or more helical grooves (9) extending into said deformable body (1) from the conduit surface to define one or more helical contact surfaces for contacting one or more medical instruments located in the conduit (5).

3. A valve component as claimed in claim 1 or 2, wherein a plurality of helical grooves (9) is provided on the conduit surface.

4. A valve component as claimed in any preceding claim, wherein three helical grooves (9) are provided on the conduit surface.

5. A valve component as claimed in any preceding claim, wherein the deformable material has a shore hardness 'A' of 5 to 20.

6. A valve component as claimed in any preceding claim, wherein the valve component is for use in a haemostatic valve.

7. A valve component as claimed in any preceding claim, wherein the pitch of one or more of said one or more helical grooves (9) is in the range 2 to 10 mm.

8. A valve component as claimed in any preceding claim, wherein helical vane diameter of the one or more helical grooves (9) is in the range 2 to 10 mm.

9. A valve assembly as claimed in any preceding claim, wherein the deformable body (1) has outer dimensions oversized by 1 to 15% relation to the housing (2).

10. A valve assembly as claimed in claim 9, wherein the body (1) and housing (2) are each cylindrical, with the external diameter of the body (1) being 1 to 15% greater than that of the internal diameter of the housing (2).

11. A valve assembly as claimed in any one of claims 9 or 10, wherein the deformable body is a first deformable body (1), a second deformable body (3) being provided having a conduit (6) for receiving said one or more medical instruments there-though, the conduits (5, 6) of the first and second deformable bodies (1, 3) having a common axis.

12. A valve assembly as claimed in claim 11, and any one or more of; a) wherein the conduit (6) of the second deformable body (3) has a widened opening at an introduction end for enhancing introduction of said one or more medical instruments; or b) wherein the conduit (6) of the second deformable body (3) has a tapered opening at an introduction end for enhancing introduction of said one or more medical instruments; or c) wherein, the first and second deformable bodies (1, 3) abut one other within the housing (2), with their conduits (5, 6) aligned.

13. A valve assembly as claimed in any one of claims 1 to 12, wherein the walls of the deformable body (1) are tapered to allow variable compression of the deformable body on movement of the deformable body (1) within the housing (2).

14. A valve assembly as claimed in any one of claims 9 to 13, further comprising a purse string suture for opening and closing the valve.