GB2050175A

GB2050175A - Atraumatic valving mechanisms

Info

Publication number: GB2050175A
Application number: GB8025739A
Authority: GB
Original assignee: Bentley Laboratories Inc
Current assignee: Bentley Laboratories Inc
Priority date: 1977-07-07
Filing date: 1978-06-22
Publication date: 1981-01-07
Also published as: IT1096907B; GB2000977A; JPS5439989A; IT7825457A0; GB2050175B; DE2829773C2; DE2829773A1; GB2000977B; FR2396555B1; JPS5745591B2; BR7804404A; FR2396555A1

Abstract

An atraumatic valving mechanism for operation within a blood passageway (103) of a blood access device, said blood passageway being arranged to connect a blood vessel within a body to the body exterior, said valving mechanism comprising: a plugging means (131) for sealing said blood passageway; a reciprocable stem member means (159) for connection to said plugging means; and a valve chamber means (151) arranged to be secured to the portion of said blood access device blood passageway at said body exterior, said valve chamber including a blood outlet (167) and an aperture (169) through which said reciprocable stem member means for connection to said plugging means may be passed. <IMAGE>

Description

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SPECIFICATION

Atraumatic valving mechanisms

5 The present invention relates to atraumatic valving mechanisms for operation within a blood passageway of a blood access device. The present application is divided out of application No. 78.27625 (Serial No. 2,000,977) 10 in which blood access devices are described and claimed.

There are a number of situations in which it is necessary to provide for fluid communication with the vascular system. For example, 15 patients suffering from kidney failure require the dialysis of their blood by means external from the body. Blood containing toxic substances, such as urea, uric acid, creatine, phosphorus and calcium, must be removed 20 from the blood system, treated and then returned to the patient. Patients requiring such blood dialysis require treatment at least two or three times per week. Patients suffering from hypoalimentation require a device for provid-25 ing access to the body's vascular system on at least a daily basis.

One prior method of providing fluid communication with the vascular system involved the insertion of a needle into an artery from 30 which blood to be treated was taken and the insertion of a needle into a patient's vein for blood return. Such a method proved unsatisfactory due to the difficulty in providing for the healing of the artery upon removal of the 35 needle and the trauma produced by the repeated needle insertions. Such shortcomings led to the development of external and, later, internal shunts.

An external shunt involves the insertion of . 40 tubes, such as those made of Teflon, into an artery and an adjacent vein in a limb and providing an external communication or shunt between the tubes, which extend from the body of the patient. The shunt between the 45 tubes is required in order to provide flow through the tubes during that period of time that access is not required for blood treatment. Were such circulating blood flow not provided, a blood clot or thrombus could form 50 as would be the case if the tubes were simply capped creating a static blood volume when the tubes were not in use. Dialysis, for example, is accomplished by connecting the arterial and venous tubing to a suitable dialysis unit. 55 However, such a configuration traumatizes the skin adjacent the Teflon tubes and a path is provided through the skin for infection to enter the patient's body. Furthermore, even with external shunts, blood clots sometimes 60 form with the tubes and create a health hazard to the patient.

The disadvantages of external shunts led to the development of the internal shunt. An internal shunt is performed by joining, within 65 a body, openings between an artery and an adjacent vein. The pressure in the artery being substantially greater than that in the vein causes the vein to become distended, forming a fistula. One or two needles were then in-70 serted into the fistula in order to achieve communication with the patient's vascular system. The patient suffers major discomfort and pain each time the needles are inserted into the fistula. Moreover, the continuous in-75 trusion into the fistula causes it to become layered with scar tissue which ultimately prevents further intrusion, thus requiring the formation of another shunt.

Both the internal and external shunts in-80 crease the loading on the patient's heart due to the joining of the artery to a vein having a lower pressure, thereby lowering the artery's pressure, and requiring the heart to attempt to regain the original arterial blood pressure. * 85 Further, in many cases, the reduced circulation in the distal portion of the limb wherein the shunt is effected impairs the adequate removal of waste products from the muscles and other tissues resulting in weakness of the 90 limb.

In application No. 78.27625, the following claims directed to blood access devices appear:

"5. A blood access device comprising: 95 a blood passageway means having an anchor means, both said blood passageway means and said anchor means being formed of either (a) a pyrolitic carbon disposed on a graphite substrate or (b) vitreous carbon, said 100 blood passageway means having a vascular graft member attached thereto arranged for attachement of said vascular graft member to the exterior surface of a blood vessel, and said anchor means being capable of establishing a 105 biological anchor.

6. A blood access device as claimed in claim 5, wherein said anchor means comprises an anchor flange having a plurality of apertures positioned about said anchor flange. 110 7. A blood access device as claimed in claim 5 or 6, wherein said blood access device includes a plugging means for sealing said blood passageway means.

8. A blood access device as claimed in 115 claim 7, wherein said blood passageway means has a generally tapered interior surface arranged to receive said plugging means which is also generally tapered, said blood passageway means having its taper inter-120 rupted by means of an annular ring, without . taper, located within the length of said blood passageway means within which said plugging means is arranged to be positioned,

thereby providing an improved sealing surface 125 for said plugging means.

9. A blood access device comprising:

a blood passageway means having a flange means at one end thereof for attachment of said flange means adjacent the exterior sur-130 face of a blood vessel, an anchor means

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attached to said blood passageway for establishing a biological anchor, said blood passageway means and said anchor means being formed of either (a) a pyrolitic carbon dis-5 posed on a graphite substrate or (b) vitreous carbon, and vascular grafting means secured to said blood passageway means adjacent said flange means for providing structural support for tissue ingrowth and for reducing blood 10 loss during healing following surgery.

10. A blood access device as claimed in claim 9, wherein said blood passageway means and said flange means are integrally formed, biocompatible, nonporous and non

1 5 biodegradable.

11. A blood access device comprising:

a blood passageway means having an anchor means, said blood passageway means and said anchor means being formed of either 20 (a) a pyrolitic carbon disposed on a graphite substrate or (b) a vitreous carbon, said anchor means being positioned about the external circumference of said blood passageway means for establishing a biological anchor; 25 and vascular grafting means attached to said blood passageway means and anchor means arranged for attachment of said vascular grafting means to the exterior surface of a blood vessel positioned annularly about said blood 30 access device, a portion of said vascular grafting means also extending from said blood passageway means in a plane substantially parallel to the plane of a blood vessel to be attached thereto.

35 12. A blood access device as claimed in any of claims 9 to 11, wherein said blood access device further comprises a plugging means arranged to be positioned within said blood passageway means for sealing said 40 blood passageway means and expelling blood therefrom.

13. A blood access device as claimed in claim 12, wherein said blood passageway

* means has a generally tapered interior surface 45 arranged to receive said plugging means which is also generally tapered, the interior surface of said blood passageway means including an annular ring of nontapered configuration arranged to provide improved sealing 50 between said plugging means and said blood passageway means.

14. A blood access device substantially as herein described with reference to and as illustrated by Figs. 1 to 7 of the accompany-

55 ing drawings."

According to the present invention, there is provided:

An atraumatic valving mechanism for operation within a blood passageway of a blood 60 access device, said blood passageway being arranged to connect a blood vessel within a body to the body exterior, said valving mechanism comprising:

a plugging means for sealing said blood 65 passageway:

a reciprocable stem member means for connection to said plugging means; and a valve chamber means arranged to be secured to the portion of said blood access 70 device blood passageway at said body exterior, said valve chamber including a blood outlet and an aperture through which said reciprocable stem member means for connection to said plugging means may be passed. 75 The mechanism can include a retaining ring for securing said valve chamber means to said blood access device, and said valve chamber means can include a plurality of slits, at the portion of said valve chamber means arranged 80 to be secured to the portion of said blood access device, in order to facilitate connection and disconnection of said valve chamber means.

Said stem member can have a threaded 85 portion arranged to be inserted within an internally threaded portion of said plugging means.

Said valve chamber can further include a blood inlet.

90 Said plugging means can have a generally tapered configuration.

Such an atraumatic valving mechanism including a plugging means having a generally tapered configuration can be in combination 95 with a blood access device of which the blood passageway has a generally tapered configuration with a nontapered portion about which said plugging means .can be placed and sealed in engaging relationship. 100 An atraumatic valving mechanism as defined above can be in combination with a blood access device as claimed in any of claims 5 to 14 of patent application No. 78.27625.

105 By way of example only, an illustrative embodiment of the invention will now be described with reference to the accompanying drawings, in which:

Figures 1 and 2 are pictorial views of a 110 blood access device,

Figure 3 is a pictorial view and partial cross-section illustrating the blood access device and a method of implantation.

Figure 4 is a cross-sectional view illustrating 115a surgical method for placing the blood access device in communication with a blood vessel.

Figures 5 and 6 are cross-sectional views illustrating the blood access device.

Figures 7 and 8 are cross-sectional views 120 illustrating a valving mechanism embodying this invention,

Figure 9 is a cross-sectional view taken about 3-3 of Fig. 2, and

Figures 10, 11 and 12 are partial cross-125 sectional views illustrating the valving mechanism embodying this invention.

The illustrated valving mechanism includes a plugging means for effecting a seal within a blood passageway of a blood access device 130 and for substantially expelling blood from the

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device upon closing, and a reciprocal stem which is connected to the plugging means and may be pushed or pulled in order to close or open the access device. The valving mech-5 anism includes a disposable connectable valve chamber which is secured about that portion of the access device blood passageway located at the body exterior. The connectable valve chamber includes a blood outlet for 10 blood flow in communication with the body blood vessel through the access device blood passageway and valve chamber and an aperture through which the reciprocal stem may be alternately actuated in order to open and 1 5 close the device in a sterile manner substantially without trauma to the body of blood passing therethrough.

Referring now to Fig. 1, a blood access device and its method of implantation will be 20 discussed. The blood access device, generally referred to as 1, is preferably formed from a relatively smooth surfaced non-porous, nonbiodegradable biocompatible material such as vitreous carbon or a pyrolytic carbon disposed 25 on a graphite substrate and includes a blood passageway 3 and a flange means 5 positioned at one end of the passageway 3. The opposite end of the passageway 3 may be provided with an external rim or lip 7 about 30 the circumference of the passageway 3.

As illustrated in Fig. 2, the flange means 5 is preferably of a generally oval configuration having a plurality of apertures 9 positioned at opposed ends of the oval flange means 5. As 35 shown in Fig. 3, such a configuration of the apertures 9 of the flange means 5 allows for the blood access device to be secured such that the apertures 9 may be bound with suitable surgical suture fiber 11 longitudinally * 40 along a blood vessel 13. An anchor flange 15 may be positioned about the external circumference of the blood passage way 3 having a plurality of uniformly spaced apertures 1 7 passing therethrough. Again, as shown in Fig. 45 3, such apertures allow for the anchor flange means 1 5 to establish a biological anchor to the body within which the blood access device 1 is implanted. During healing the body tissues 21 may pull away somewhat from the 50 upper portion of the blood access device as shown in Fig. 3. When this occurs the anchor flange 1 5 acts as an effective barrier to the bacteria which might otherwise enter about the device 1. A vascular grafting material 19, 55 formed from polyurethane, Dacron, an E. I. Du Pont de Nemours & Co. trademarked product of polyester fiber made from polyethylene terephthalate, or the like is preferably positioned about the exterior surface of the 60 blood passageway 3 and extends in-a plane generally parallel to that of the face of the flange means 5. During implanting surgery, the vascular grafting material 1 9 can be trimmed somewhat as shown in Fig. 3 in 65 order to accommodate the size and shape of the blood vessel 13. While Fig. 3 shows the grafting material 19 positioned about a portion of the circumference of the blood vessel 13, it can be attached so as to completely 70 surround blood vessel 13. The vascular grafting material 1 9 provides for reducing blood loss during healing following implantation surgery as the material does not allow blood to pass through it. The vascular grafting material 75 19 has a further advantage in that it provides a structural support for tissue ingrowth which allows the blood access device 1 to become secured to the blood vessel 13 and the body tissues, referred to generally in Fig. 3 as 21; 80 Fig. 3 further depicting skin 18, fat 20, fascia 22 and muscle 24.

Fig. 4 illustrates the removal of that portion of the blood vessel, referred to as 23, which is encompassed within the flange means 5. 85 That portion of blood vessel 13 adjacent the blood access device 1 is clamped in order to prevent blood flow through the vessel 13. The blood vessel portion 23 is secured by means of a retractable member 25 which is passed 90 downwardly through the blood passageway 3 and which can have one or more barbs 26 for securing the blood vessel portion 23. The blood vessel portion 23 of the blood vessel 1 3 can then be severed by means of an 95 annular cutting element 27 having its cutting edge 29 preferably positioned at the outer extremity of the diameter of the cutting instrument 27. After the blood vessel portion 23 has been severed from the blood vessel 1 3, it 100 may be removed by retracting the securing member 25. Upon removal of the cutting means 27 and the removable member 25, together with the secured blood vessel portion 23, a plug means 31 may be inserted within 105 the blood passageway 3, and the blood vessel 1 3 can be clamped. The plug means 31 is preferably formed of low density polyethylene or other like electrically deformable material and generally tapered along its exterior and 110 adapted to be inserted within the blood passageway 3. The blood passageway 3 may be provided with an annular discontinuity or un-tapered portion of its tapered length, shown in Fig. 5 as a vertical ring 38. This annular ring 115 38 provides for an improved seal between the plugging means 31 and the blood passageway 3. The plugging means 31 is preferably of a configuration such that it will completely seal the volume of the blood passa-1 20 geway 3 so that no blood remains in the access device 1 upon insertion of the plugging means 31.

As shown in Fig. 6, the plugging means 31 can be secured by means of a cap member 125 33 and a retaining ring 35 having a number of vertical slits 39 to facilitate its engagement and removal. The cap means 33 is preferably cosmetically colored and provided with an annular lip portion 37 which engages the lip 1 30 or rim 7 of the blood access device 1, thereby

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effecting a seal therebetween.

Referring now to Fig. 7, the blood access device and its use with a substantially atraumatic valving mechanism embodying this in-5 vention, will be discussed. The blood access device, generally referred to as 101, includes a blood passageway 103 having an external rim or lip 107, an anchor flange 11 5 and a flange means 105. The flange means 105 is 10 positioned adjacent a blood vessel 113 and secured thereto by means of suitable surgical suture fiber 111 which is also passed through apertures 109 within the flange means 105.

Fig. 7 further illustrates the use of vascular 1 5 grafting material 119 which both provides for reducing blood loss during implantation surgery and provides structural support for tissue ingrowth which allows the blood vessel 113 and body tissues to be securely anchored to 20 the blood access device 101. Fig. 7 illustrates a patient's skin 118, fat 1 20, fascia 112 and muscle 124 within which the blood access device 101 is anchored. A plugging means 1 31 is shown positioned within the blood 25 passageway 103 adapted to prevent blood flow therethrough and to expel blood from the blood passageway 103 upon insertion. The blood passageway is preferably tapered as illustrated in Fig. 7, the taper having an 30 untapered portion along its tapered length as shown as a vertical ring 138 in Fig. 7 in order to provide an improved seal between the plugging means 131 and the blood passageway 103. The plugging means 131 is 35 preferably restrained within the blood passageway 103 by means of a cap means 133 and a thread retaining ring 135 having a number of vertical slits 139 to facilitate the engagement and removal of the retaining ring 40 135.

When it is desired to remove blood from the patient's vascular system, restraining ring 135 is unthreaded thereby allowing cap :» means 133 to be removed. A connector or 45 valve chamber generally referred to as 151 is positioned about the external rim or lip 107 of the blood access device 101 and retained in such a position by retaining ring 135. The valve chamber 151 is preferably provided 50 with an engaging lip 153 which mates with ring 107 of the blood access device 101. The valve chamber 151 is also provided with a plurality of slits 139 in order to facilitate its engagement and removal, as was true with 55 respect to cap means 133.

Plugging means 131 is provided with an internally threaded aperture 155 adapted to engage the threaded portion 157 of a reciprocal stem member 159. The stem member 60 159 is rotated, as by means of a wheel assembly 161 suitably secured to the stem, member 159 as by means of a screw 163 ; until the stem member 159 is securely connected to the plugging means 131 by means . 65 of engagement of the threaded portion 157 of the stem member 1 59 with the internally threaded aperture 155 of the plugging means 131. The valve chamber 151 is further provided with a cavity portion 165 adapted to 70 receive at least a portion of the plugging means 131 when said stem member 159 and connected plugging means 131 are pulled from said blood passageway 103 so as to allow blood flow from the blood vessel 113 75 through the blood passageway 103.

The valve chamber 151 is also provided with a blood outlet 167 and an aperture 169 through which said stem member 159 is allowed to slide or reciprocate as the stem 80 member 15 is pushed or pulled in order to close or open the valving mechanism embodying this invention or rotate it in order to engage or disengage said plugging means 131. Suitable seals 171 and 173, such as O-85 ring seals, can be employed in order to prevent blood loss during the operation of the valve mechanism embodying this invention. Suitable retaining means such as annular locking members 175 can be utilized in order to 90 provide for a secure connection between the valve chamber 1 51 and a tube 177 utilized to transfer blood.

Fig. 9 illustrates a cross-sectional view of the embodiment of the invention showing Fig. 95 8 taken about lines 9-9. Fig. 10 more clearly illustrates the valving mechanism embodying the present invention when the valve is in the open position as contrasted with the closed position of Fig. 8. Figs. 11 and 12 illustrate 100 two alternative arrangements of the valving mechanism for blood treatment. Fig. 11 illustrates an arrangement wherein blood is alternately removed for treatment and returned to the body through a single tube 177. Fig. 12 105 illustrates an arrangement wherein two connections to said valve chamber 151 are provided, 167a and 1676, each having corresponding tube connections 177a and 1 lib. The embodiment as illustrated in Fig. 12 110 allows for blood removal through one valve chamber connection and blood return through a separate connection. Preferably, the cross-sectional area of the annular opening 179 between plugging means 131 and the blood 115 passageway 103 is at least equal to the cross-sectional area of the blood passageway 103 at the location 181 where the blood passageway 113 is connected to the blood vessel 113.

120 The described blood access device may be permanently implanted through a patient's skin providing access to the vascular system while enabling full circulation throughout the system since no external or internal shunt is 1,25 required;. The device may also be used for : '• • patients that have an internal shunt. ' i 1 The described valving mechanism is used in ' a blood access device which has been perma-. _/ = nently implanted through a patient's skin in 130 order to provide access to the patient's vascu

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lar system while enabling full circulation throughout the vascular system as no external or internal shunt is required.

After a blood access device has been im-5 planted within a patient's body providing access to a blood vessel of the patient's vascular system, the embodiment of the present invention provides for the substantially atraumatic opening and closing of a valve within the 10 blood access device allowing for blood treatment substantially without trauma to the patient's blood or body tissues surrounding the blood access device.

The valving mechanism embodying this in-15 vention includes a valve chamber which may be connected to that portion of the blood access device blood passageway which is positioned at the body exterior. The valve includes means for gently opening and closing a " 20 plugging means positioned within the valve passageway in order to allow for blood flow therethrough. When the plugging means is positioned in its closed configuration, the blood within the blood passageway is substan-25 tially expelled into the body's vascular system, therefore reducing the possibility of infection and the formation of blood clots.

Claims

30 1. An atraumatic valving mechanism for operation within a blood passageway of a blood access device, said blood passageway being arranged to connect a blood vessel within a body to the body exterior, said valv-35 ing mechanism comprising:

a plugging means for sealing said blood passageway;

a reciprocable stem member means for connection to said plugging means; and 40 a valve chamber means arranged to be secured to the portion of said blood access device blood passageway at said body exterior, said valve chamber including a blood outlet and an aperture through which said 45 reciprocable stem member means for connection to said plugging means may be passed.
2. An atraumatic valving mechanism as claimed in claim 1, wherein the mechanism includes a retaining ring for securing said

50 valve chamber means to said blood access device, and said valve chamber means includes a plurality of slits, at the portion of said valve chamber means arranged to be secured to the portion of said blood access device, in 55 order to facilitate connection and disconnection of said valve chamber means.
3. An atraumatic valving mechanism as claimed in claim 1 or 2, wherein said stem member has a threaded portion arranged to

60 be inserted within an internally threaded portion of said plugging means.
4. An atraumatic valving mechanism as claimed in any preceding claim, wherein said valve chamber further includes a blood inlet.

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5. An atraumatic valving mechanism as claimed in any preceding claim, wherein said plugging means has a generally tapered configuration.
6. An atraumatic valving mechanism as 70 claimed in claim 5 in combination with a blood access device of which the blood passageway has a generally tapered configuration with a nontapered portion about which said plugging means can be placed and sealed in 75 engaging relationship.
7. An atraumatic valving mechanism substantially as herein described with reference to and as illustrated by Figs. 8 to 11 of the accompanying drawings.

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8. An atraumatic valving mechanism as claimed in claim 7 but modified substantially as herein described with reference to and as illustrated by Fig. 12 of the accompanying drawings.

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9. An atraumatic valving mechanism as claimed in any of claims 1 to 5, 7 and 8 in combination with a blood access device as claimed in any of claims 5 to 14 of patent application No. 78.27625.

Printed for Her Majesty's Stationery Office by Burgess & Son (Abingdon) Ltd.—1980.

Published at The Patent Office, 25 Southampton Buildings,

London, WC2A 1AY, from which copies may be obtained.