US20040167478A1

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Publication number: US20040167478A1
Application number: US10/789,181
Authority: US
Inventors: Charles Mooney; Robert Pecor; Donald Bobo; Michael Higgins; Manouchehr Miraki; Erik Bulman; Gary Willoughby
Original assignee: Edwards Lifesciences Corp
Current assignee: Edwards Lifesciences LLC
Priority date: 1996-11-26
Filing date: 2004-02-26
Publication date: 2004-08-26
Also published as: US6827710B1

Abstract

A multiple lumen access device for use in providing a single entry port into the human body for selectively introducing medical implements therethrough and for providing simultaneous auxiliary access into the body. The multiple lumen access device includes a multi-lumen sheath which may have an outer tube and structure defining a device lumen located therein. The inner structure may be an inner wall or inner tube. The outer tube and inner structure are located so as to define at least one auxiliary lumen. Some embodiments include flexible inner walls which can be flexed between relaxed and expanded/contracted positions wherein the relative cross-sectional areas of the device lumen and auxiliary lumens are varied. The access device further includes a valve which provides sealing of the device lumen. The valve may be provided in a lumen junction housing or separate from the housing either permanently or removably connected with the device lumen. Alternatively, a multi-lumen sheath may be passed through a valve leading to a conventional introducer. The valve may also be molded separately as a rigid insert and retained in a cavity formed in a flexible junction housing. In other embodiments, the multiple lumen access device is formed by introduction of the elongated implement coaxially within a tubular single lumen sheath.

Description

RELATED APPLICATIONS

The present application is a divisional of Ser. No. 09/329,002, filed Jun. 8, 1999, entitled MULTIPLE LUMEN ACCESS DEVICE, which is a continuation-in-part of co-pending U.S. application Ser. No. 08/953,105, filed Oct. 17, 1997, which is a continuation-in-part of U.S. application Ser. No. 08/756,763, filed Nov. 26, 1996 under the same title, abandoned. The entire contents of both of these prior applications are hereby incorporated by reference.[0001]

BACKGROUND OF THE INVENTION

1. Field of the Invention[0002]

The present invention relates generally to medical devices which are used to provide access into the human body. More particularly, the present invention is directed to access devices which provide a single, relatively long-term, entry port into the body. The entry port is used by doctors and other medical professionals to selectively introduce a variety of medical implements and fluids into the body and for in vivo diagnostic testing and other treatment protocols.[0003]

2. Description of Related Art[0004]

A wide variety of medical devices have been developed in recent years for providing access into the human blood stream. These devices have traditionally been divided into two different groups based on their function and purpose. The first group of devices includes catheters which are designed to introduce therapeutic and/or diagnostic fluids into the blood stream. The second group includes devices commonly referred to as “introducers” which are designed to provide an intermediate term access port into the body through which various medical implements may be passed for therapeutic and/or diagnostic purposes. As a generalization, catheters are longer and more flexible than introducers.[0005]

Central venous catheters are relatively long tubular devices which have tapered distal tips which are designed for entry into central veins to provide a dedicated route of fluid infusion into the body. The original venous catheters were single lumen devices which provided the ability to infuse a single liquid into the vein at one time. Multiple lumen catheters have since been developed which allow simultaneous introduction of two or more liquids into the vein. The central venous pressure catheter is a type of common multiple lumen catheter which allows the simultaneous introduction and withdrawal of fluids as well as the capability of monitoring blood pressure and other vital parameters. The portion of the catheter which remains outside of the body has been continually refined and redesigned to provide a low profile which increases comfort and reduces the awkwardness associated with a dedicated tube exiting the body.[0006]

Introducers are substantially different from catheters in both design and purpose. An introducer is an access device which is intended to provide a dedicated access port into the body. Catheters, on the other hand, are intended to be used to infuse or withdraw fluids from the body. Introducers typically include a relatively short lumen through which various medical implements, including catheters, can be selectively introduced and removed from the body. An important feature of any introducer is the valve assembly. The valve assembly provides a constant seal between the blood stream and the in vitro environment as medical implements are introduced and withdrawn from the body. The valve assembly is typically located outside of the body at the proximal end of the introducer. As a result, the proximal end of introducers has tended to be relatively bulky.[0007]

In addition to a valve assembly, many introducers include a side arm at the proximal end. The side arm is connected to the lumen so that fluids can be introduced into the body simultaneously with the medical device. The introducer lumen is considered to be a “shared” lumen in that the lumen provides a common conduit for both medical implements and fluid pharmaceuticals or diagnostics.[0008]

The currently available introducers and other access devices are well-suited for their intended purpose. However, new medical treatments and diagnostic procedures are continually being developed which require more versatile access into the body. For example, organ transplant procedures and cardiac angioplasty require the introduction of complex combinations of medical implements and diagnostic/therapeutic fluids into the body. Many of the presently available access devices are not well-suited for these relatively complex procedures. As a result, multiple access devices are required which must be located at multiple access sites necessitating multiple entry punctures. Accordingly, there is a continuing need to provide improved access devices that have additional capabilities which increase their versatility and usefulness for the increasing variety of invasive treatments and procedures.[0009]

SUMMARY OF THE INVENTION

In accordance with the present invention, an improved access device is provided which is designed to provide selective introduction of medical implements into the body while simultaneously providing auxiliary access through dedicated multiple lumens. The present invention is an improvement over existing introducers and other access devices in that multiple lumen access is provided through the introducer in addition to the shared lumen which is used for both medical implements and fluid pharmaceuticals or diagnostics. As an advantage, the improved access device reduces the number of devices required to introduce multiple implements and fluids into the body during complex surgical and diagnostic procedures.[0010]

The present invention desirably includes a multiple lumen access system for use in providing an entry port into the human body for selectively introducing medical implements therethrough and for providing simultaneous auxiliary access into the body. The system includes a multiple lumen access device comprising an outer tube which has a distal end for introduction into the body and a cross-sectional area. A device lumen through which medical implements may be passed is defined within the cross-sectional area of the outer tube, the device lumen having a distal end and a proximal end. At least one auxiliary lumen is defined within the cross-sectional area and separately from the device lumen, the auxiliary lumen having a distal end and proximal end. Finally, a device lumen valve is associated with the proximal end of the device lumen to provide sealing of the device lumen when medical implements are both present and absent from the device lumen. Such device lumen valve may be separate and detachable or it may be integral with the system.[0011]

A multiple lumen access system according to the present invention may also include a junction housing having a proximal end and a distal end to which the proximal end of the outer tube connects. The junction housing includes a main channel in fluid communication with the device lumen and at least one auxiliary channel in fluid communication with the at least one auxiliary lumen, the main channel and auxiliary channel(s) diverging from the outer tube to be non-intersecting in the junction housing.[0012]

In one embodiment, the device lumen valve is provided as a part of the junction housing and is in fluid communication with the main channel. A device channel may be formed in the junction housing at an angle with the main channel and terminating at an internal end in fluid communication with the main channel. The device lumen valve may be positioned at an external end of the device channel so that medical devices may be inserted therethrough and enter the main channel at an angle. The main channel desirably may continue from the distal end of the junction housing past the device lumen to an opening in the junction housing enabling introduction of fluids therethrough to the main channel. In one embodiment, the device lumen valve is molded separately from the junction housing of a material more rigid than the junction housing and is assembled with the multiple lumen access device by insertion in a cavity formed in the junction housing.[0013]

In an alternative embodiment, the main channel and auxiliary channel(s) of the junction housing may be oriented substantially coplanar so that the junction housing is substantially flat, the system further including an extension tube extending from the proximal end of the junction housing and in fluid communication with the main channel wherein the device lumen valve is connected to the extension tube to therefore be in fluid communication with the main channel. A side port in the device lumen valve may be provided enabling infusion of fluids to the extension tube and main channel. Furthermore, mating threaded connectors may be included between the device lumen valve and the extension tube enabling easy removal of the device lumen valve. Any appropriate connector, for example a luer connector, may be provided on the device lumen valve, and the system may also include an infusion syringe having a mating luer connector.[0014]

Further, in one embodiment, a multiple lumen access device may be provided with a multi-lumen sheath, a junction housing coupled to the multi-lumen sheath and a strain relief insert coupled to the junction housing. The strain relief insert is formed of a soft bendable material capable of flexing to prevent multi-lumen sheath from kinking at the sheath/junction housing coupling. In further embodiment, the multiple lumen access device is formed by coupling a single lumen catheter to a junction housing having a main channel and at least one auxiliary channel through a multi-function adapter.[0015]

In another embodiment, the present invention is directed to a multiple lumen access device including an outer tube which has a distal end for introduction into the body and a proximal end which remains outside of the body. The outer tube may have an exterior surface and an interior surface, the interior surface defining an access passageway which has a cross-sectional area which may vary at different locations between the distal and proximal ends of the outer tube. One or more inner walls are located within the access passageway. The inner wall may form an inner tube that surrounds a device lumen through which medical implements may be inserted into the body. At least one auxiliary lumen is located between the exterior surface of the inner wall and the interior surface of the outer tube.[0016]

As another feature of the present invention, two or more auxiliary passageways defined by the interior surface of the outer tube and the exterior surface of the inner walls. The provision of two or more auxiliary passageways allows introduction of additional diagnostics or pharmaceutical liquids simultaneously with introduction of a medical implement through the device lumen. Embodiments of the present invention are also described wherein a single auxiliary lumen is provided.[0017]

As a further desirable feature of the present invention the inner walls are sufficiently flexible to be movable from a relaxed position to expanded or contracted positions. The device lumen has a first cross-sectional area in the relaxed position, and in the expanded or contracted positions has cross-sectional areas which are greater than or less than the first cross-sectional area, and less than the cross-sectional area of the access passageway. The flexibility of the inner walls is advantageous in that it allows the insertion of a variety of medical implements having different cross-sectional areas. This flexibility allows the cross-sectional areas and resultant potential fluid flow rate for the auxiliary lumens and the device lumen to be controlled as desired and maximized within the confines of the access passageway.[0018]

As an additional feature of the present invention, spacer ribs are provided, for example, on the interior surface of the outer tube. The spacer ribs are located within the auxiliary lumens to prevent complete closure of the lumens during insertion of relatively large medical implements into the device lumen. The spacer ribs located on the surface of the inner wall insure that there is a passageway around devices located within the device lumen.[0019]

An alternative multiple lumen access device of the present invention comprises a tubular single lumen sheath having at least one infusion port and an elongated implement sized to fit coaxially within the single lumen sheath and form multiple independent lumens, and when at least one of the lumens is in fluid communication with the infusion port. The elongated implement may be formed from a sufficiently flexible material so that at least one lumen formed by the sheath and the implement has flexible walls movable from a relaxed to a flexed positions. Another alternative multiple lumen access device comprises a multi-lumen catheter having a main lumen tube, at least one side lumen tube connected in a side-by-side fashion with the main lumen tube and being peelable from the main lumen to form sidearms, and a hub connected to the main lumen tube and side lumen tube for fluid delivery or passage of a medical device therethrough.[0020]

The present invention is also directed to a method for introducing medical devices into the body through a single entry port while allowing simultaneous introduction of other devices, implements or fluids through the use of the multiple lumen access device of the present invention. In one embodiment, the method includes the steps of providing a multiple lumen access device in accordance with the present invention having at least one flexible wall; introducing the multiple lumen access device into the body with the distal ends of the device lumen and the auxiliary lumen being positioned within a vasculature of the body; and flowing a medical solution through the auxiliary lumen to move the flexible wall from the relaxed position to a flexed position.[0021]

In another embodiment, the method includes the steps of providing a tubular single lumen sheath having proximal and distal ends, at least one infusion port being provided on the proximal end of the sheath; providing an elongated implement sized to fit coaxially within the single lumen sheath, at least one of the lumens being in fluid communication with the infusion port; inserting the elongated implement into the single lumen sheath to form multiple independent lumens therein; and flowing a medical solution through one or more of the multiple independent lumens.[0022]

The above-described and many other features and attendant advantages of the present invention will become better understood by reference to the following detailed description when taken in conjunction with the accompanying drawings.[0023]

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a perspective view of an exemplary preferred multiple lumen access device in accordance with the present invention.[0024]

FIG. 2 is a sectional view of FIG. 1 taken in the[0025]2-2 plane of FIG. 1.

FIG. 3A is a sectional view taken in the same[0026]2-2 plane of FIG. 1 which shows a relatively small diameter medical device located within the device lumen.

FIG. 3B is a sectional view taken in the same[0027]2-2 plane of FIG. 1 showing a relatively large diameter medical implement located within the device lumen.

FIG. 4 is a sectional view of FIG. 1 taken in the[0028]4-4 plane.

FIG. 5 is a sectional view of FIG. 1 taken in the[0029]5-5 plane.

FIG. 6 is a perspective view of a preferred exemplary embodiment in accordance with the present invention.[0030]

FIG. 7 is a sectional view of FIG. 6 taken in the[0031]7-7 plane.

FIG. 8 is a sectional view of FIG. 6 taken in the[0032]8-8 plane.

FIG. 9 is a sectional view of a preferred exemplary flexible inner wall showing the location of spacing ribs.[0033]

FIG. 10 is a sectional view of a preferred exemplary multiple lumen access device having a single auxiliary lumen.[0034]

FIGS.[0035]11A-C are sectional views of an exemplary multiple lumen access device showing a relatively small diameter medical implement located in a central device lumen and the inner walls in relaxed conditions (11A), partially collapsed about the implement due to pressurization of side auxiliary lumens (11B), and substantially completely collapsed about the implement (11C).

FIG. 11D is a sectional view of an alternative multiple lumen access device having flexible walls made of a material different from the material of the outer tube of the multiple lumen access device.[0036]

FIG. 12 is a graph illustrating an increase in the cross-sectional area (in gauge size) of an auxiliary lumen, such as in the cross-section shown in FIGS.[0037]11A-11C, as the differential pressure between the auxiliary lumen and the device lumen changes.

FIG. 13 is a sectional view of an alternative multi-lumen sheath for use in the present invention having a device lumen on one side and two side-by-side auxiliary lumens.[0038]

FIG. 14 is a sectional view of an alternative multi-lumen sheath for use in the present invention having a device lumen on one side and two stacked auxiliary lumens.[0039]

FIG. 15 is a sectional view of an alternative multi-lumen sheath for use in the present invention having no flexible walls therein.[0040]

FIG. 16 is a perspective view of a further embodiment of a multiple lumen access device in accordance with the present invention.[0041]

FIG. 17 is a perspective sectional view of FIG. 16 taken in the[0042]17-17 plane.

FIG. 18A is a perspective view of an extrusion die for making a sheath portion of the multiple lumen access device of the present invention.[0043]

FIG. 18B is an end view of a sheath portion of the multiple lumen access device as extruded from the die shown in FIG. 18A.[0044]

FIGS. 18C and 18D are isolated views of inner extrusion molds of the die shown in FIG. 18A with exemplary dimensions for the sheath portion cross-section called out.[0045]

FIG. 19 is an enlarged perspective view of a junction housing of the device shown in FIG. 16.[0046]

FIG. 20 is an enlarged perspective of the junction housing of FIG. 19 with a portion cut away on the longitudinal axis.[0047]

FIG. 21 is a perspective assembled view of a valve insert used in the junction housing of FIG. 16.[0048]

FIG. 22 is an exploded perspective view of the valve insert of FIG. 21.[0049]

FIGS. 23A and 23B are two perspective views of a multiple lumen access device similar to that shown in FIG. 16.[0050]

FIG. 24 is an elevational view of the multiple lumen access device of FIGS.[0051]23A/23B in place in the vasculature of a patient.

FIG. 25A is a perspective view of a junction housing of the device shown in FIGS. 23 and 24 showing a valve insert and strain relief insert both exploded therefrom.[0052]

FIG. 25B is a reversed perspective view of the strain relief insert adapted to be coupled to the junction housing in FIG. 25A.[0053]

FIG. 26 is an exploded elevational view of the valve insert shown in FIG. 25A.[0054]

FIG. 27 is a perspective view of a clamp portion for the valve insert of FIG. 26.[0055]

FIGS. 28A and 28B are perspective views of an adapter which mates with the valve inserts of FIGS.[0056]21 or26.

FIG. 29 is an elevational view of a multiple lumen access device in accordance with the present invention.[0057]

FIG. 30 is a plan view of the multiple lumen access device of FIG. 29 showing more details of an associated catheter system.[0058]

FIG. 31 is a perspective view of a proximal end of a low-profile junction housing of the device of FIG. 29.[0059]

FIG. 32 is a plan view of an alternative multiple lumen access device with a low profile junction housing.[0060]

FIG. 33 is a detailed view of an alternative introducer valve assembly for use in the device of FIGS.[0061]30 or32.

FIG. 34 is a plan view of an alternative multiple lumen access having a multi-lumen infusion catheter interfacing with a single lumen introducer.[0062]

FIGS.[0063]35A-35D are schematic sectional views of sheath/lumen configurations for use in the multi-lumen infusion catheter of FIG. 34.

FIG. 36 is a sectional view of a junction housing used in the device of FIG. 34.[0064]

FIG. 37 is an elevational view of a further embodiment of a multi-lumen sheath for use in the device of FIG. 34.[0065]

FIG. 38 is a sectional view of the multi-lumen sheath of FIG. 37.[0066]

FIG. 39 is a plan view of a multiple lumen access device having a center tube and two side lumen tubes in accordance with the present invention.[0067]

FIGS. 40A and 40B are sectional views of a sheath of the multiple lumen access device of FIG. 39 taken along[0068]

lines

40A-40A and40B-40B, respectively.

FIG. 41 is an alternative multiple lumen access device with discrete tubes as in FIG. 39 and having a junction housing.[0069]

FIG. 42A is an exploded view of a multiple lumen access device having an introducer connected to a multi-lumen catheter by an adjustable adapter.[0070]

FIG. 42B is an assembled view of the multiple lumen access device of FIG. 42A.[0071]

FIG. 43A is an exploded view of a multiple lumen access device having an introducer with infusion port connected to a multi-lumen catheter by an adapter.[0072]

FIG. 43B is an assembled view of the multiple lumen access device of FIG. 43A.[0073]

FIG. 44A is an exploded view of a multiple lumen access device having an introducer with infusion port connected to a triple lumen junction housing and obturator by an adapter.[0074]

FIG. 44B is an assembled view of the multiple lumen access device of FIG. 44A.[0075]

FIG. 45A is an exploded view of a multiple lumen access device having an introducer connected to triple lumen junction housing by a threaded adapter.[0076]

FIG. 45B is an assembled view of the multiple lumen access device of FIG. 45A.[0077]

FIG. 46A is an exploded view of a multiple lumen access device having an introducer connected to triple lumen junction housing and elongated infusion tube by a threaded adapter.[0078]

FIG. 46B is an assembled view of the multiple lumen access device of FIG. 46A.[0079]

FIG. 47A is an exploded view of a multiple lumen access device having an introducer with infusion port telescopically fitting within a larger introducer.[0080]

FIG. 47B is an assembled view of the multiple lumen access device of FIG. 47A.[0081]

FIG. 48A is an exploded view of a multiple lumen access device with a multi-ribbed hollow obturator telescopically fitting within an introducer with infusion ports.[0082]

FIG. 48B is an assembled view of the multiple lumen access device of FIG. 48A.[0083]

FIG. 49 is an assembled view of a multiple lumen access device similar to that shown in FIG. 48B with infusion ports formed on a hub of the multi-ribbed hollow obturator.[0084]

FIG. 50A is an exploded view of a multiple lumen access device with a multi-ribbed solid obturator telescopically fitting within an introducer with infusion ports.[0085]

FIG. 50B is an assembled view of the multiple lumen access device of FIG. 50A.[0086]

FIG. 51 is an exploded sectional view of a multiple lumen access device with a multi-ribbed hollow obturator telescopically fitting within a tapered introducer with an infusion port.[0087]

FIG. 52 is an assembled view of the multiple lumen access device of FIG. 51.[0088]

FIG. 53 is a sectional view of the obturator seen in FIG. 51 taken along line[0089]53-53.

FIG. 54 is a perspective view of a portion of the obturator seen in FIG. 51.[0090]

DESCRIPTION OF THE PREFERRED EMBODIMENTS

An exemplary multiple lumen access device (MLAD) in accordance with the present invention is shown generally at[0091]10 in FIGS.1-5. Thedevice10 includes anouter tube12 which has a distal end14 and aproximal end16. As best shown in FIGS.2-5, theouter tube12 has anexterior surface18 and aninterior surface20. Theinterior surface20 defines an access passageway orlumen22 which has a cross-sectional area that may vary at different locations between the distal14 and proximal16 ends of theouter tube12. Typically, theouter tube12 may be tapered at the distal end14, if desired. As a result of the tapering of theouter tube12, the cross-sectional area will decrease accordingly.

In accordance with the present invention, an[0092]

inner tube

24 is located within theaccess passageway22. Theinner tube24 has a distal end and a proximal end which correspond to the distal end14 andproximal end16 of theouter tube12. As illustrated in FIG. 2, theinner tube24 is formed by a wall surrounding adevice lumen30, the wall having anexterior surface26 and aninterior surface28. Theinterior surface28 defines adevice lumen30 through which medical implements (such as

catheters

32 and34 shown in FIGS. 3A and 3B, respectively) may be inserted into the body.Catheter34 is also shown in position within thedevice lumen30 in FIGS. 4 and 5.

Two[0093]

auxiliary lumens

36 and48 are located between theexterior surface26 of theinner tube24 and theinterior surface20 of theouter tube12. The

auxiliary lumens

36 and48 each have a distal end and a proximal end which correspond generally to the distal and proximal ends of theouter tube12 andinner tube24. In this particular preferred embodiment, the surfaces which define the

auxiliary lumens

36 and48 correspond to portions of the interior surface of the outer tube and exterior surface of the inner tube. Specifically,auxiliary lumen36 is defined or bordered by aninterior surface38 which corresponds to theinterior surface20 of theouter tube12 and theexterior surface26 of theinner tube24. Further, theauxiliary lumen36 is defined by

separation surfaces

40 and42 which are formed byseparation barriers44 and46, respectively.

A second[0094]

auxiliary lumen

48 is also formed or defined by theinterior surface20 of theouter tube12 and theexterior surface26 of theinner tube24. Accordingly, theinterior surface50 which defines the secondauxiliary lumen48 corresponds to these surfaces. In addition, theauxiliary lumen48 is bordered by

separation surfaces

52 and54 formed byseparation barriers44 and46, respectively.

Referring to FIG. 1, the multiple[0095]

lumen access device

10 includes ajunction housing56. Thejunction housing56 is connected to theproximal end16 of theaccess lumen12. Thehousing56 includes

infusion tubes

58 and60 which are connected through thehousing56 to

auxiliary lumens

36 and48, respectively. The

infusion tubes

58 and60 includeluer connectors62 and64. Other conventional connection devices may be used. Athird infusion tube66 is connected via thehousing56 to thedevice lumen30 in order to provide a route for infusion of liquid into thedevice lumen30. It should be noted that theinfusion tube66 is not connected to thejunction housing56 at a right angle as is typically done in conventional introducer-type devices. Instead, theinfusion tube66 extends from thehousing56 parallel to the other two

infusion tubes

58 and60. This parallel orientation of the

tubes

58,60 and66 allowshousing56 to be a low profile body which reduces the bulkiness of the proximal end of the device and increases its wearing comfort. A conventional locking device, such asluer lock68 is also provided at the proximal end of theinfusion tube66.

The[0096]

housing

56 includes avalve70 through which various medical implements are inserted into thedevice lumen30.Valve70 includes a valve or gasket assembly which is designed to provide sealing of thedevice lumen30 when medical implements are both present and absent from thedevice lumen30. Any of the known gasket arrangements and valve mechanisms used to provide sealing of introducers and related medical implement access devices are suitable. The multiplelumen access device10 is designed for use in combination with providing access to either the arterial or venous sides of the bloodstream.

An opening[0097]72 (see FIG. 1 and FIG. 5) is provided towards the distal end ofouter tube12. Theopening72 is provided to allow exit of fluid fromauxiliary lumen48 which has been introduced throughinfusion tube58. Likewise, an opening74 (shown in phantom in FIG. 1 and also shown in FIG. 4) is provided for allowing the fluid introduced throughinfusion tube60 to exitauxiliary lumen36 at the distal end of theouter tube12.

As illustrated in FIGS. 1, 4 and[0098]5, the

openings

72 and74 are preferably sized to avoid restricting fluid flow through the respective auxiliary lumens. Therefore, it is preferred that the

openings

72 and74 are each sized sufficiently large to be equal or greater than the maximum distended/expanded cross-sectional area of the corresponding

auxiliary lumens

36 and48. Of course, this same principle applies with regard to any number of auxiliary lumens each having a variable cross-section. When either

auxiliary lumen

36,48 is under pressure and no device is present in thedevice lumen30, the auxiliary lumen cross-section increases in diameter. In one preferred embodiment, the auxiliary lumen increases, for example, from approximately 15 gauge to about 12 gauge, while in another embodiment the auxiliary lumen increases from approximately 18 gauge to about 14 gauge. Therefore, the

openings

72 and74 are each sized to be equivalent to or greater than 12 gauge or 14 gauge, respectively, to avoid restricting fluid flow through the respective auxiliary lumen. When other cross-section diameters of the auxiliary lumens are used, the size of the openings, such as72 and74, are preferably sized accordingly.

In this exemplary embodiment of the present invention, the[0099]

inner tube

24 must be sufficiently flexible to be stretchable between a relaxed position as shown in FIG. 3A and various expanded positions as exemplified in FIG. 3B. In FIG. 3A, acatheter32 having a diameter of 1.3 millimeter (4 French) is shown inserted within thedevice lumen30. Theinner tube24 is in a relaxed position where the cross-sectional area of thedevice lumen30 is approximately 2 square millimeters. The relaxed cross-sectional area of thedevice lumen30 will preferably range from 1 to 3 square millimeters. Larger diameters are possible, if desired. It is preferred, but not required, thatinner tube24 have a circular or elliptical cross-section.

As shown in FIG. 3B, a[0100]

larger diameter catheter

34 has been inserted into thedevice lumen30. Theinner wall24 is made from sufficiently resilient material and is sufficiently sized so that it can expand to the diameter shown which is approximately 3 millimeter (9 French). The maximum diameters to which theinner tube24 can be expanded is limited by the diameter of theouter tube12. Theinner tube24 may be flexed inward, if desired, by applying fluid pressure through one or both

auxiliary lumens

36 and48. Typically, the cross-sectional area of thedevice lumen30 when theinner tube24 is in its maximum expanded state will range from 5 to 9 square millimeters. Larger diameters are possible, if desired. Preferably, theinner tube24 will be sufficiently flexible so that it can be expanded completely outward against theinterior surface20 of theouter tube12. In the fully expanded state, the

auxiliary lumens

36 and48 will have substantially reduced cross-sectional areas. However, it is preferred that the

auxiliary lumens

36 and48 not be entirely closed. It is desirable to leave some opening through these two

auxiliary lumens

36 and48 at all times to allow flushing fluids to be passed through the lumens in order to prevent the formation of blood clots or other problems associated with a completely collapsed lumen.

Preferably, the[0101]

inner tube

24 is sufficiently flexible to be stretched to expanded positions wherein the cross-sectional area of thedevice lumen30 in the expanded state is up to 85 percent of the cross-sectional area of theaccess lumen22. This allows for continual auxiliary fluid introduction through

auxiliary lumens

36 and48. Further, it is preferred that in the relaxed position as shown in FIG. 3, that thedevice lumen30 have a cross-sectional area which is not less than 35 percent of the cross-sectional area of theaccess lumen22.

In accordance with the present invention, the[0102]

inner tube

24 is preferably connected to theouter tube12 atseparation barriers44 and46 in order to divide theaccess lumen22 into a three-chamber lumen, i.e. thecentral device lumen30 and two

auxiliary lumens

36 and48. In order to achieve the desired flexibility of thedevice lumen30, it is preferred that a relatively elastic material be utilized. Suitable elastic materials include, but are not limited to, polyvinylchloride, polyurethane, polyethylene, nylon, silicone, fluoropolymers and polypropylene. Further, in order to achieve the desired variation in lumen cross-sectional areas, the thickness and durometer of theinner tube walls24 must be carefully matched to the particular material being utilized. For less flexible materials, the wall thicknesses must be correspondingly reduced in order to achieve the desired flexibility limits. Theinner tube24 should be sufficiently flexible so that it can be expanded to diameters which are at least as large as theouter tube12.

Another exemplary embodiment in accordance with the present invention is shown generally at[0103]100 in FIG. 6. Theaccess device100 is similar to the previous preferred embodiments in that it includes an outer tube112 having a distal end114 and aproximal end116. As best shown in FIGS. 7 and 8, the outer tube112 has an exterior surface118 and an interior surface120. The interior surface defines an access passageway122 in which aninner tube124 is located. Theinner tube124 includes anexterior surface126 and aninterior surface128. Theinterior surface128 of theinner tube124 defines adevice lumen130 through which medical implements, such as a catheter, may be inserted. Theaccess device100 includes threeseparation barriers132,134 and136 which, in combination with the interior surface of the outer tube120 and exterior surface of theinner tube126, form threeauxiliary lumens138,140 and142. The multiplelumen access device100 includes the same type of junction housing144 which was described in the previously-described preferred embodiment (FIGS.1-5), except that an additional infusion lumen is included to provide infusion of liquid into the additional auxiliary lumen. As shown in FIG. 6,

infusion lumens

146,148 and150 are connected via junction housing144 toauxiliary lumens138,140 and142, respectively. Aprimary infusion lumen152 is also provided for introducing fluids into thedevice lumen130. Again, an access port154 is provided with the appropriate gaskets and/or valving mechanism to allow introduction of catheters and other medical devices into thedevice lumen130.

The[0104]

inner tube

124 in this exemplary embodiment may or may not be made from flexible material. The inclusion of three separation barriers in this particular embodiment reduces the ability for flexible expansion and contraction of theinner tube124. However, it is preferred that the material used to form thedevice lumen124 and the separation barriers be more flexible than the exterior outer tube112 in order to allow variations in the cross-sectional areas of the auxiliary lumens. Otherwise, the same materials and fabrication techniques which are used to fabricate the prior embodiments are also suitable for use in making the multiplelumen access device100.

In a preferred embodiment, as shown in FIG. 9,[0105]

spacer ribs

210 are provided on theinterior surface220 of the outer tube212 to prevent theinner tube224 from being expanded to a position which closes the

auxiliary lumens

236 and248.Spacer ribs211 may also be provided to insure that apassageway213 is maintained around adevice215 when it is located withindevice lumen230. Theribs210 are preferably located longitudinally along the entire length of the outer tube212 where theinner tube224 is also present. The particular cross-sectional shape of thespacer ribs210 is not particularly important so long as they are relatively blunt and do not damage theinner tube224 during contact therewith. The number and relative positioning of the spacer must be chosen to insure that complete closure of the

auxiliary lumens

236 and248 does not occur. Forinner tubes224 which are relatively flexible, the number and size of ribs may have to be increased. Theribs210 shown in FIG. 9 are an example of a preferred configuration. The number, shape, size and position of theribs210 may be varied as required in order to prevent closure of the

auxiliary lumens

236 and248 as discussed above.

Although more than two auxiliary lumens may be included into the access device, it is preferred that two lumens be utilized. The use of two lumens is a preferred design for allowing uniform expansion of the[0106]

inner tube

24 between the relaxed state as shown in FIG. 3A and an expanded state as shown in FIG. 3B.

Access devices which include one auxiliary lumen are also possible. The cross-section of an exemplary access lumen is shown at[0107]310 in FIG. 10. Theaccess lumen310 includes anouter tube312 which defines anaccess lumen322. Theaccess lumen322 is divided into adevice lumen330 and anauxiliary lumen336 by an innerflexible wall324. The inner surface of theouter wall312 preferably includes spacer ribs (shown in phantom at350) to prevent closure of theauxiliary lumen336. Theinner wall324 is made from the same types of flexible materials as described previously for the inner tubes used in the multiple auxiliary lumen embodiments. This particular embodiment is well-suited for use in those situations where a relatively large device lumen is required in favor of the advantages provided by multiple auxiliary lumens.

The[0108]

outer wall

12 is preferably made from any of the well-known polymer materials used in fabricating introducers and other access devices. Exemplary materials include polyurethane, polyethylene, polypropylene, nylon, polyester, polyether/ester copolymers, silicone based polymers, metalocene catalyzed polyolefins or ethylene vinyl acetate and synthetic rubbers. Preferably, the material used and wall thicknesses for theouter wall12 are such that theouter wall12 is a relatively stiff tube in relation to theinner tube24. Further, the material used for theouter wall12 should be compatible for molding purposes with the material used to form theinner wall24. It is preferred that theouter wall12 andinner wall24 be extruded together, as will be more fully described below. Theouter wall12 andinner wall26 may be made from the same material or different materials. Theinner wall26 is preferably made from softer versions of the various polymers listed above. When using different materials, the materials must be compatible for bonding or fusing together.

Other fabrication techniques for connecting the inner and outer tubes are possible provided that the connection between the two lumens at the[0109]

separation barriers

44 and46 extends the entire length of the two lumens and provides a solid integral connection between the lumens. For example, radio frequency (RF) welding of the tubes is another possible fabrication procedure which may be used to make the access lumen in accordance with the present invention. If desired, the entire triple lumen can be extruded as a single integral multiple lumen structure.

During use, the[0110]

exemplary access device

10 allows introduction of medical implements into the device lumen while at the same time allowing infusion of fluid throughtube66 also into device lumen, as well as allowing infusion through

tubes

58 and60 into

auxiliary lumens

48 and36, respectively. Since, as discussed above, theouter tube12 is relatively inflexible in the radial direction (though overall longitudinally flexible), the total available cross-sectional area for insertion of medical implements and flow of fluids is limited for a given access device. However, the flexibility of the device lumen allows the doctor or other medical professional to selectively and fully utilize the total available cross-sectional area.

In FIG. 3A, a relatively[0111]

small catheter

32 is shown inserted within thedevice lumen30. In this configuration, fluids may be infused/removed through the unused area of thedevice lumen30 as well as the two

auxiliary lumens

36 and48. It should be noted that the preferred design inherently centers the catheter or medical implement32 so that the

auxiliary lumens

36 and48 have approximately equal cross-sectional areas. However, it should be noted that the application of differential pressure to the

infusion tubes

58 and60 can be used to selectively increase or decrease the relative cross sectional areas available for infusion of fluids through the auxiliary lumens. For example, the size ofauxiliary lumen36 can be increased relative to the cross-sectional size ofauxiliary lumen48 by introducing the infusion of liquid throughtube58 at a pressure which is relatively higher than that oftube60. The double auxiliary lumen design of this exemplary embodiment is especially well suited for providing such differential fluid flows when desired.

An exemplary embodiment which further demonstrates the flexibility of devices in accordance with the present invention is demonstrated in FIGS.[0112]11A-11C. In FIG. 11A, anexemplary access device21 is shown in which a relativelysmall catheter33 is located within thedevice lumen31. In this configuration, fluids may be infused/removed through the unused area ofdevice lumen31 as well as the two

auxiliary lumens

37 and49. As shown in FIG. 11A, the innerflexible walls25 is in a relaxed position. In this position, theinner wall25 is relatively close to theouter wall15. When desired, the size of the

auxiliary lumens

37 and49 can be increased substantially by increasing the pressure of liquids being passed therethrough. The result, as shown in FIG. 11B, is the partial collapsing of the inner tube orinner walls25 about thecatheter33. In the partially contracted or collapsed position as shown in FIG. 11B, theinner walls25 are not stretched. Instead, their configuration changes as shown in FIG. 11B to accommodate the change in relative sizes of the auxiliary lumens and device lumen. As shown in FIG. 11C, the size of

auxiliary lumens

37 and49 are increased even further to a point where the fluid flow through the two auxiliary lumens is maximized. In this condition, stretching of the contractedflexible walls25 may occur. As is apparent from FIGS.11A-11C, it is possible to provide a wide variance in fluid flows through the auxiliary lumens and device lumen depending upon differential pressures applied through the various lumens.

Alternative Sheath Cross-Sections[0113]

FIG. 13 illustrates an alternative cross-section of a[0114]

sheath portion

340 for the multiple lumen access device of the present invention in which the device lumen is not between two auxiliary lumens. The sheath portion of the devices of the present invention comprise the portion that is distally disposed with respect to the junction housing, defines multiple lumens therein, and is substantially inserted into the patient's vasculature. In FIG. 13, thesheath portion340 comprises an outer tube342 defining within, and, in series from left to right, adevice lumen344, a firstauxiliary lumen346, and a secondauxiliary lumen348. A firstflexible wall350 separates thedevice lumen344 from the firstauxiliary lumen346, while asecond wall352, that can be flexible or relatively rigid, separates the first and second

auxiliary lumens

346,348. The firstflexible wall350 can move from its position shown in solid line to the dashed-line position shown at354 as the pressure difference across the wall increases in favor of the firstauxiliary lumen346. Likewise, the secondflexible wall352, if flexible, can move from its position shown in solid line to the dashed-line position shown at356 as the pressure difference across the wall increases in favor of the secondauxiliary lumen348.

FIG. 14 is a further alternative cross-section of a[0115]

sheath portion

360 for the multiple lumen access device of the present invention. The embodiment of FIG. 14 is similar to that shown in FIG. 13, and includes adevice lumen362, firstauxiliary lumen364, and secondauxiliary lumen366, all defined with anouter tube368. In contrast to the embodiment of FIG. 13, the

auxiliary lumens

364 and366 are not arranged side-by-side, but are instead stacked on top of one another (at least in the orientation shown) so that both are located adjacent thedevice lumen362. In this respect, a generally T-shaped internal dividing wall is provided including anelongated wall portion370 and ashorter wall portion372. Theshorter wall portion372 separates the first and second

auxiliary lumens

364,366, while theelongated wall portion370 separates the two auxiliary lumens from thedevice lumen362. Both theelongated wall portion370 and theshorter wall portion372 are curvilinear in their relaxed configurations, shown in solid line in FIG. 14. The

wall portions

370 and372 straighten out into the dashed-line positions upon an increase in pressure in one or both of the

auxiliary lumens

364,366 relative to thedevice lumen362.

In another alternative embodiment, not illustrated, the device lumen can be provided between two or more auxiliary lumens of different sizes. The device lumen is typically positioned off-center between crescent-shaped auxiliary lumens, and at least one of the auxiliary lumens can be expandable in accordance with the preceding discussion (that is, a wall between one of the auxiliary lumens and the device lumen is flexible). Desirably, there are two auxiliary lumens and the larger of the two lumens is expandable to enable infusion of large flow rates. In one particularly preferred embodiment, the larger lumen has a capacity equivalent to a gravity flow through a 14 gauge lumen.[0116]

FIG. 15 illustrates a still further cross-sectional view of a[0117]

sheath portion

380 which may be used in conjunction with the multiple lumen access device of the present invention. In this embodiment, thesheath portion380 includes a generally cylindricalsolid member382 having acentral device lumen384 and a plurality ofauxiliary lumens386 surrounding the device lumen formed therein. There are no flexible walls in this embodiment, it being understood that various aspects of the present invention may be advantageously utilized without the need for varying the cross-sectional shape of any of the lumens within thesheath portion380. Alternatively, if desired, any wall portion separating thedevice lumen384 from any of theauxiliary lumens386 may be formed to be flexible to enable variability of the cross-section of that lumen.

The graph illustrated in FIG. 12 shows that as pressure inside the auxiliary lumen increases the cross-sectional area of that lumen increases. (The convention is that cross-section in terms of “gauge” numbers actually decreases for larger areas). FIG. 12 reflects the pressure response of one exemplary multi-lumen catheter wherein the auxiliary lumen increases in size from about 15 gauge when there is no flow therethrough, to about 12 gauge with fluid infusion at a pressure of about 300 mmHg (in this sense, the 300 mmHg is the differential pressure across the flexible wall, if the assumption is made that the device lumen is at atmospheric pressure). The response curve of the increase in lumen size indicates that the flexible wall is sufficiently rigid to withstand small changes in pressure. From 0-150 mmHg, the auxiliary lumen increases only from slightly smaller than 15 gauge to slightly larger than 15 gauge. Only above 150 mmHg pressure differential does the lumen size significantly increase. This response is a factor of the thickness, shape and material of the flexible wall between the device and auxiliary lumens.[0118]

One of the advantages of having an inner wall[0119]25 (as seen in FIG. 11A) or inner wall350 (as seen in FIG. 13) which is flexible but also sufficiently rigid is that a pressure transducer may be connected to the multi lumen access device of the present invention to monitor a central venous pressure of a patient. In particular, the pressure transducer (not shown) may be placed in communication with one of the

auxiliary lumens

37 and49 to measure the central venous pressure. Advantageously, the resistance to small pressure differentials described above enables more accurate pressure monitoring, because the flexible wall does not substantially flex upon small differentials in pressure, and thus does not dampen or attenuate the resultant pressure wave sensed externally to the lumen. Specifically, the flexibleinner walls25 have sufficient stiffness to avoid significant damping or attenuation of pressure pulses in the

auxiliary lumens

37 and49, and do not undergo major flexing from small pressure differentials as shown in FIG. 12.

As described previously in regards to the exemplary embodiment illustrated in FIGS.[0120]1-5, theouter wall15 of the embodiment illustrated in FIGS.11A-11C is preferably made from any of the well-known polymer materials used in fabricating introducers and other access devices. Preferably, the material used and wall thickness for theouter wall15 are such that theouter wall15 is a relatively stiff tube in relation to theinner walls25 in the radial direction. Further, the material used for theouter wall15 should be compatible for molding purposes with the material used to form theinner walls25. It is preferred that the entire cross-section of the multi-lumen portion of thedevice10, including theouter tube12 andinner walls25, is extruded together from a homogeneous material. Alternatively, theouter wall15 andinner walls25 may be coextruded and that the junctions27 be formed by molding of the inner25 andouter wall15 together during the coextrusion process, as seen in FIG. 11D. Therefore,outer wall15 andinner walls25 may be made from the same material or different materials, as shown in FIG. 11D. Theinner wall25 is preferably made from softer versions of the various polymers listed previously. When using different materials, the materials should be compatible for bonding or fusing together.

The above described exemplary embodiments may be used in the same manner as conventional introducer devices. Additionally, if desired, the devices may be used in the same manner as conventional central venous pressure catheters. As will be appreciated by those skilled in the art, the present invention provides the design flexibility to allow use as a single device where the capabilities of an introducer device and catheter are simultaneously required. For example, many diagnostic and invasive medical procedures require the insertion of guide wires and/or medical devices, while simultaneously monitoring critical bodily functions and introducing or removing fluids as needed. The access device of the present invention allows all of the above functions to be performed simultaneously and selectively through a single access device.[0121]

MLAD with Valve Insert[0122]

FIG. 16 illustrates an alternative multiple lumen device[0123]400 (MLAD) in accordance with the present invention with animproved junction housing402. Thedevice400 is similar to the FIGS.1-5, and includes amultiple lumen sheath404 extending distally from thehousing402. The multiple lumen sheath has adistal end406 for insertion in a body cavity and aproximal end408 attached to thehousing402. A plurality ofextension tubes410 is attached to the proximal end of thehousing402 and terminate inluer connectors412. The housing comprises avalve insert portion414 and a lowprofile lumen portion416. Avalve insert418 is secured in a cavity defined in theportion414. A pair of mountingwings420 is integrally formed with thejunction housing402 for attaching to a patient.

The[0124]

multiple lumen sheath

404 seen in cross-section in FIG. 17 comprises an outercircular tube422 having aninterior surface424. In the illustrated embodiment, themultiple lumen sheath404 includes acentral device lumen426 and a pair ofauxiliary lumens428 disposed on opposite sides of the device lumen. Thedevice lumen426 is defined betweeninterior surfaces430 of a pair ofdivider walls432. The divider walls extend in a non-linear fashion substantially across the entireouter tube422 and terminate atjunctions434. Thejunctions434 are spaced a slight distance from one another so that thesheath404 does not exhibit the separation barriers, as previously described. As illustrated, thedevice lumen426 is generally concentrically positioned within theouter tube422 and has a nominal diameter of slightly greater than half theouter tube422. Betweenexterior surfaces436 of thedivider walls432 and theinterior surfaces424 of theouter tube422, theauxiliary lumens428 are formed. Thelumens428 are substantially crescent shaped and are shown identical in size. Of course, as described previously, various other lumen configurations can be provided in themultiple lumen sheath404.

The[0125]

junction housing

402 is illustrated in greater detail in FIGS. 19 and 20. The lowprofile lumen portion416 has an oval cross-section tapering gradually wider along its long axis from themultiple lumen sheath404 to aproximal face440 to which theextension tubes410 connect. Thevalve housing portion414 angles upward from one wide surface of thelumen portion416 and terminates in aproximal face442. The deviceaccess valve insert418 fits within an angled cavity formed in thevalve housing portion414. With specific reference to FIG. 19, thelumen portion416 comprises amain channel444 and a pair ofauxiliary channels446 on either side. The main channel communicates with acentral extension tube410, while theauxiliary channels446 communicate with the side extension tubes. Adevice channel448 defined within thevalve housing portion414 is in communication with themain channel444 and angles upwardly therefrom to terminate in awidened cavity450. Thecavity450 receives thevalve insert418 which is held therein by acircumferential lip452 on the outermost portion of thecavity450. Thecavity450 continues inward from thelip452 towards thedevice channel448 and narrows at astep454. Thestep454 provides a stop surface against which thevalve insert418 is pressed. Desirably, theinsert418 andcavity450 are keyed to facilitate insertion in a particular rotational orientation and prevent further rotation.

Valve Insert[0126]

Now with reference to FIGS. 21 and 22, the device[0127]

access valve insert

418 is seen in greater detail. Thevalve insert418 comprises four components: anouter frame460, awiper462, a valve464, and a sleeve466. The assembledvalve insert418 is seen in FIG. 18. Thewiper462 and valve464 are juxtaposed within anouter wall468 of theframe460, and held therein by the interaction between aflange470 of the sleeve466 and a pair of cantilevered latches472 provided on the frame. The sleeve466 further includes asupport tube474 projecting downward from theflange470 and surrounding the valve464. Thewiper462 includes anaperture476 through which device catheters may be inserted in a sealed fashion. The valve464 may be a conventional duck-billed valve having avalve slit478, as seen in FIG. 17. The combination of thewiper462 and the valve464 effectively seals thedevice channel448 formed within thejunction housing402 and the exterior of the junction housing when devices are repeatedly introduced and withdrawn through thevalve insert418. Theouter wall468 further includes a pair ofpartial threads480 which cooperate with exterior threads on an infusion catheter dilator or contamination shield (not shown).

The[0128]

entire valve insert

418 is formed separately from thejunction housing402, which is molded from a soft, flexible material, typically a soft thermoplastic material. The softness of thejunction housing402 is important in enhancing patient comfort and flexibility of the entiremulti-lumen access device400 when assembling and mounting to a patient. Conversely, theframe460 of thevalve insert418 is relatively rigid for supporting thewiper462 and duck-billed valve464. The wiper and duck-billed valve are made of elastomeric materials, and theouter wall468 prevents valve depression or distortion and thus enhances the patency of the seal formed by thevalve insert418. The sleeve466 stabilizes the elastomeric valve components, and thesupport tube474 provides an outer surface against which the duck-billed valve464 cannot extend past. The rigidity of thevalve insert418 provides structure to facilitate connection of devices thereto. Furthermore, thejunction housing402 is easily injection molded over themultiple lumen sheath404 andtubes410 prior to addition of theinsert418, for a simplified manufacturing process.

Sheath Cross-Section Formation and Details[0129]

FIG. 18A illustrates in perspective an extrusion die[0130]390 used to extrude a preferred cross-section of sheath portion of a multiple lumen access device of the present invention, such as the cross-section shown in FIG. 17. The extrusion die390 comprises a largetubular member392 having abore393, and a plurality of lumen-forming mandrels positioned longitudinally therein. Specifically, a device lumen-forming mandrel394 and two surrounding auxiliary lumen-forming mandrels396a,396bare positioned within thebore393 using elongated pins (not shown) closely fitting within guide holes398.

As it is known in the extrusion art, material such as polyurethane in liquid form can be forced through the cavities formed between the[0131]

bore

393 and the mandrels394,396 and gradually cooled so that when the material exits from the extrusion cavity it has solidified somewhat and retains the shape shown in FIG. 18B.

FIG. 18B is a cross-sectional view of the[0132]

exemplary sheath

404 of FIG. 16 and includes anouter tube422 and twoinner walls436 together definingdevice lumen426 and the surroundingauxiliary lumens428, as described in more detail below.

FIGS. 18C and 18D are more detailed views of the surfaces of the mandrels[0133]394 and396 in one preferred embodiment of the present invention. The outer diameter of the auxiliary lumen-forming mandrels396 is given as D₁, and the outer surfaces are centered about axis C₀. The inner surfaces of the mandrels396 are defined by several arcs. As seen in FIG. 18D, a first inner surface portion as a radius R₁centered about axis C₁, while second portion has radius R₂centered about axis C₂.

The device lumen-forming mandrel[0134]394 includes two diametricallyopposed ribs398 having a thickness A, and a central non-uniform convex body defined by several arcs that generally conform to the inner surfaces of the auxiliary lumen-forming mandrels396. More specifically, the exemplary mandrel394 includes convex surfaces that are identical in the four quadrants shown and have a first radius R₃centered about axis C₃, and a second radius R₄centered about axis C₀. A minimum gap indicated at G_minis defined between the convex outer surfaces of the device lumen-forming mandrel394, and the concave inner surfaces of the auxiliary lumen-forming mandrels396. The minimum gap G_minthus forms the thinnest portions of thewalls436 of the device of the present invention.

Along the diametric plane that is normal to the diametric plane through the[0135]

ribs

398, both extrusion mandrels exhibit a curvature toward the axis C₀. Namely, the device lumen-forming mandrel394 has a concave outer surface portions with the radius R₅, and both of the auxiliary lumen-forming mandrels396 have a convex portion with a radius R₆. The configuration of these curvilinear portions creates a maximum gap between the mandrels indicated at G_max. The maximum gap G_maxthus forms the thickest portions of thewalls436. Thewalls436 are initially spaced apart a distance B.

Exemplary dimensions of the extrusion die and the corresponding cross-section of the device sheath are given in the table below:[0136]

TABLE I


Extrusion Mandrel Configuration

		VALUE
	DIMENSION	(in, mm)

	D₁	0.325, 8.26
	R₁	0.172, 4.37
	R₂	0.0956, 2.43
	R₃	0.0574, 1.46
	R₄	0.1195, 3.04
	R₅	0.0382, 0.97
	R₆	0.0201, 0.51
	A	0.0306, 0.78
	B	0.2007, 5.10
	G_min	0.0099, 0.25
	G_max	0.0182, 0.46

The dimensions shown in Table 1 are strictly exemplary, and the multiple-lumen access device of the present invention by no means is limited to these particular dimensions.[0137]

The resultant cross-section of the sheath after extrusion through the[0138]

die

390 is seen in both FIGS. 17 and 18B. The twowalls436 each connect to theouter tube422 at closely-spaced locations that are approximately diametrically opposed. Thewalls436 bow away from one another in their relaxed states, with each generally following the curvature of theouter tube422 to form therebetween theauxiliary lumens428. Thedevice lumen426 is formed between thewalls436 which are well-suited to collapsing upon a positive pressure gradient generated between anauxiliary lumen428 and the device lumen. That is, the narrow gaps G_minformed in the extrusion die create regions in eachwall436 that are weak in bending. As the pressure differential across thewalls436 increases in favor of theauxiliary lumen428, the thickest portion created by the gap G_maxtends to be forced inward first because of the bending of the thinnest portions. If a device is positioned within thedevice lumen426, thewalls436 will contact it at the thickest portions first. This behavior is shown for a different sheath cross-section in FIGS.11A-11C. As a result, the line contact between thewalls436 and the device facilitates sliding movement of the device through the sheath. That is, thewalls436 bend such that a large surface area is prevented from contacting the device, and thus the frictional resistance to sliding movement is minimized.

Alternative MLAD with Valve Insert[0139]

FIGS. 23A and 23B are different perspective angles of an exemplary multiple[0140]

lumen access device

500 of the present invention, which is in many respects very similar to thedevice400 shown in FIG. 16. Thedevice500 includes ajunction housing502, adistal sheath504, and a plurality ofproximal extension tubes510 terminating inluer connectors512. One of the main distinctions from the earlier described embodiment is the provision of astrain relief insert514 positioned at the distal end of thejunction housing502. In addition, an alternative device valve insert is provided, but is not seen in FIGS. 23A and 23B and will be described in detail below. Finally, a plurality of conventional finger-actuatedclamps516 are mounted on theextension tubes510.

FIG. 24 is a side elevational view of the[0141]

device

500 of FIG. 23 showing thedistal sheath504 inserted through theouter tissue518 of a patient and into avessel520. The flexible nature of thesheath504 is seen in this figure, as well as the ability of thejunction housing502 to live flat against the patient's skin. As mentioned above, the material used and wall thicknesses for the outer tube of thesheath504 are such that the outer tube is a relatively stiff tube in relation to the inner flexible walls. Nevertheless, theentire sheath504 is sufficiently pliable so as to enable slight bending along its length which facilitates insertion into the patient's vessel and comfortable placement against the skin. The soft material used in making thejunction housing502 further prevents irritation to the patient. In addition, thestrain relief insert514 is located adjacent the most extreme bend of thesheath portion504 and helps prevent kinking of the internal lumens.

Alternative Valve Insert[0142]

FIG. 25A is a perspective view of the[0143]

junction housing

502 with thestrain release insert514 exploded from the distal and, and components of an alternative devicelumen valve insert522 exploded from the proximal end. Thestrain relief insert514 is additionally shown at a different angle in FIG. 25B. FIGS. 26 and 27 illustrate the components of thealternative valve insert522 in greater detail.

FIGS. 26 and 27 illustrate the alternative device[0144]

access valve insert

522 which includes a tactile feedback feature. Thevalve insert522 comprises four components: aclamp524,wiper526,valve528, and lowerouter frame530. Thewiper526 andvalve528 are juxtaposed within anouter wall531 of the lowerouter frame530, and held therein by the securement of theclamp524 onto the lowerouter frame530 by a pair oflatches532 which engage with mating lugs534. Theclamp524 includes a pair ofpartial threads536 which cooperate with exterior threads of an infusion catheter dilator or contamination shield (not shown). A pair ofgrooves538 is disposed on acontact face540 ofclamp524. Thewiper526 includes anaperture542 through which device catheters may be inserted in a sealed fashion. Thevalve528 may be a conventional duck-billed valve having a valve slit, as seen at464 in FIG. 22. As described previously in regards to thedevice valve insert418 shown in FIGS. 21 and 22, the combination of thewiper526 and thevalve528 effectively seals the device channel formed within the junction housing and the exterior of the junction housing when devices are repeatedly introduced and withdrawn through thevalve insert522.

The upper portion of the[0145]

valve insert

522 is relatively rigid and may be formed from the same material as the lowerouter frame530 such as acrylic, polysulfone, or other high durometer materials. It is also noted that thevalve insert522 shown in FIG. 26 may be used for the exemplary multi-lumen access devices shown in FIGS. 1, 6, and16.

Contamination Shield Adapter[0146]

FIGS. 28A and 28B illustrate an[0147]

adapter

550 for a distal end of a contamination shield. Theadapter550 includesthreads552 which mate with thethreads536 of the upper portion of thevalve insert532 illustrated in FIGS. 26 and 27. Thethreads552 of theadapter550 are designed to fully engage with thethreads536 of theclamp524 by a ¼ turn of theadapter550. A pair oflugs554 are disposed on the contactingsurface556 of theadapter550 such that thelugs554 mate with the pair ofgrooves538 of theclamp524. As the ¼ turn is completed, thelugs554 snap into thegrooves538 and create a tactile feedback. Thecontamination shield550 sealingly receives a flexible tubular sheath thereover to provide a sterile channel that is alternately collapsible and extensible around devices inserted through the device valve. Such contamination shields are well known in the art and will not be further described.

Strain Relief Insert[0148]

A multiple lumen access device may kink at the multi-lumen sheath/junction housing interface when the access device is attached to a patient. The kink may reduce the cross-sectional area of the multi-lumen sheath or in extreme circumstances, result in blockage of the lumens. The “kink” problem may be resolved by providing a multiple lumen access device with the[0149]

strain relief insert

514 as illustrated in FIGS. 23A, 23B,24, and25A. Again, theaccess device500 is similar to the access device described in FIG. 16 with the exception that thejunction housing502 is modified to accept thestrain relief insert514. Thestrain relief insert514 is connected to the distal end of thejunction housing502, and over themulti-lumen sheath504.

The[0150]

strain relief insert

514 has an oval cross-section tapering gradually wider along its long axis from themulti-lumen sheath504 to thejunction housing502. As seen in FIG. 25A, the low profile lumen portion578 of thejunction housing502 also has an oval cross-section tapering gradually wider along its long axis from thestrain relief insert514 to aproximal face580 to which the extension tubes (not shown) connect. Thestrain relief insert514 includes atapered body582 havingribs584 which gradually blend into the body. Theseribs584 allow thestrain relief insert514 to flex and prevent the multiple-lumen sheath504 from kinking.

In order to achieve the desired flexibility of the[0151]

strain relief insert

514, it is preferred that a relatively soft, elastic material be utilized. Suitable elastic materials include, but are not limited to, polyurethane and pellathane with a 55D shore hardness. Further, in order to achieve the desired flexibility, the thickness of thestrain relief insert514 must be carefully matched to the particular material being utilized. For less flexible materials, the wall thickness should be correspondingly reduced in order to achieve the desired flexibility limits. Thestrain relief insert514 may be formed using radio frequency (RF) technology with appropriate forming dies and fixtures. Desirably, thestrain relief insert514 is overmolded onto thesheath504 and subsequently coupled to thejunction housing502 at the time that the housing and sheath are connected.

MLADS with Remote Introducer Valves[0152]

FIGS. 29 and 30 illustrate a further embodiment of the multiple lumen access device[0153]600 in which thedevice access valve602 is not formed integrally with thejunction housing604. More particularly, as best seen in FIG. 29, thejunction housing604 has a low profile which is slightly greater than thesheath606 orextension tubes608 attached thereto. FIG. 31 shows a proximal end of lowprofile junction housing604 illustrating threechannels610 formed therein for communication with threeextension tubes612, seen in FIG. 30. Acentral extension tube612 connects with aremote introducer valve614 which has aproximal opening616 for device catheter access. Within theintroducer valve614, a number of different duck-bill or other valves may be provided to seal the lumen of theextension tube612 from the exterior.Introducer valve614 may include a sideport extension tube618 terminating in aluer lumen hub619 for attaching to infusion fluid sources. Thus, in this alternative configuration, a single needle stick followed by implantation of themulti-lumen sheath606 is all that is required to obtain the benefits of both an introducer valve and central venous catheter, as described previously. Alternatively, the multiple lumen access device600 further includes an auxiliary lumen valve connected to at least oneother extension tube612 than the central tube to therefore provide a valved entry to at least one of the auxiliary lumens within thesheath606 as well as with the device lumen.

In a further alternative of the device[0154]600, FIG. 32 illustrates a multiplelumen access device620 wherein thecentral extension tube622 terminates in aluer connector624. Theluer connector624 is desirably used to mate with afemale luer connector626 of anintroducer valve assembly628. However, in this detachable configuration, various other medical devices having conventional luer fittings may be attached to theluer connector624 and placed in communication with a central lumen of themulti-lumen sheath630. FIG. 33 illustrates a further alternative, wherein theintroducer valve assembly632 is provided with amale luer connector634 on a proximal end to which aninfusion syringe636 may be attached. As can be seen, various configurations are possible with the remoteintroducer valve assembly628, and the lowprofile junction housing621 is easily molded over the extension tubes and has a reduced size, thus facilitating the manufacturing process.

MLAD with Multi-lumen Catheter and/or Introducer Combination[0155]

FIG. 34 illustrates a further alternative multiple[0156]

lumen access device

650 comprising amulti-lumen infusion catheter652 in combination with a conventional single-lumen introducer valve654. Themulti-lumen infusion catheter652 includes ajunction housing656 which interfaces a plurality ofproximal extension tubes658 and amulti-lumen sheath660 extending distally therefrom. FIG. 36 illustrates one way in which theproximal extension tubes658 can be routed to communicate with a plurality of tubes662 providing lumens of themulti-lumen sheath660. Themulti-lumen sheath660 is sized to fit through theintroducer valve654 having a distal sheath664, and from there into the body. In this manner, a single-lumen introducer may be implanted into the patient and then used further as an access port for themulti-lumen infusion catheter652. By leaving the introducer in place, only a single stick is necessary to enjoy both introducer and central venous catheter capabilities.

With specific reference to FIG. 36, a[0157]

proximal insert

666, and adistal insert668 are mounted around the array ofextension tubes658, and distal tubes662, respectively. Thehousing656 is then formed by injection molding material around and between the

inserts

666 and668. Avalve seal expander670 may be provided to help keep the duck-bill valve within theintroducer valve654 open. Further, lockingthreads672 are preferably provided to interface with theintroducer valve housing654.

FIGS.[0158]35A-D show various configurations of themulti-lumen sheath660. In FIG. 35A, a three-lumen solid configuration having a larger high-pressure lumen674 is shown. FIG. 35B illustrates a four-lumen embodiment which has an outer sheath680 so that fluid may be passed between the sheath and the exterior of the four tubes within. FIG. 35C is similar to the four-lumen sheath of FIG. 35B, but includes a singlelarge lumen682 and a plurality of smaller lumens684. Finally, FIG. 35D illustrates an arrangement of lumens having a central high-volume high-pressure lumen686, and a plurality ofsmaller lumens688 attached around the circumference in an even array.

FIGS. 37 and 38 illustrate a further embodiment of a multi-lumen sheath[0159]690 having a central, high-pressure tube692 and a plurality of outer or auxiliary tubes694.

MLAD with Multiple Discrete Tubes[0160]

FIG. 39 illustrates a[0161]

multi-lumen catheter device

700 having at least two discrete catheter tubes. In this embodiment, themulti-lumen catheter device700 includes a main (or center)lumen tube702 and twoside lumen tubes704. The

lumen tubes

702 and704 are configured in a side-by-side fashion, and proximal portions of the

tubes

702,704 are peeled apart to create sidearms.Hubs706 may be attached to proximal ends of each

lumen tube

702,704 for fluid delivery or introduction of a medical device. Remote introducer valves may be connected to one or all the lumen tubes. Indeed, the device valves may be provided on any or all of the extension tubes for the various embodiments described herein and shown in any of the figures, including FIGS. 1, 6,23A,30. Thecatheter device700 may further include asleeve708 at the region where the

lumen tubes

702 and704 branch outwardly. FIGS. 40A and 40B illustrate the different cross-section of thedevice700, the circular shape of the sleeve providing a smooth transition for sealing through a puncture wound into the skin. One of the advantages of this embodiment is that one or more of the

lumen tubes

702 and704 may be peeled off themulti-lumen catheter700 if desired.

FIG. 41 illustrates another alternative[0162]

multi-lumen catheter device

710. Thiscatheter device710 is similar to thecatheter device700 illustrated in FIG. 39 and includes the additional feature of ajunction housing712 connected to a proximal end of amain lumen tube714. Thejunction housing712 receives avalve insert716 and anextension tube718 with ahub720 connected to its proximal end. Again, the separate tubes can be peeled away to create various lumen devices.

Multiple Lumen Catheter through Introducer[0163]

FIGS. 42A and 42B illustrate a multi-function adapter[0164]730 for connecting different components, for example, catheters and introducers, for use with the present invention. The multi-function adapter include a first unit and a second unit that are complementary and enable a quick-release connection of a multiple lumen device and an introducer. By way of example and not limitation, the multi-function adapter may include a female unit730aand a male unit730b. The male unit730bincludes at least onelug732 extending radially outward, while the female unit730aincludes a slot (not illustrated) which accepts and interlocks with the lug. The slot may be a variety of configurations to securely interlock the male unit with the female unit, such as an L-shaped channel, a bayonet lock, an interference fit, etc. Other types of adapters known in the art such as luers may be utilized as long as components of the access device can be easily connected/disconnected.

In the embodiment of FIGS. 42A and 42B, the adapter[0165]730 couples amultiple lumen catheter734 with anintroducer735. Thecatheter734 may be a CCO catheter or other multiple-lumen device, and includes ajunction housing736 between a distalmulti-lumen sheath738 and a plurality ofproximal extension tubes740. Theintroducer735 includes ahub742 with aside arm744 for introducing or withdrawing fluids. The female unit730ais adapted to fit over thesheath738 by a press fit, adhesive, or any other means generally known in the art. Conversely, the male unit may be fixedly attached to thesheath738 or distal end of thejunction housing736 instead of the female unit, if desired. The adapter730 permits detachability of themultiple lumen catheter734 from theintroducer735 and provides great flexibility in surgical or critical care situations.

FIGS. 43A and 43B illustrate a multiple-lumen access device[0166]760 very similar to the device of FIGS. 42A and 42B but with the adapter formed as part of a multiple lumen catheter junction housing. The access device760 includes an introducer762 connected to a Central Venous Catheter (CVC) or othermultiple lumen catheter764 by amulti-function adapter766aand766b. Thecatheter764 includes a multiple-lumen sheath768 connected to ajunction housing770.

The access device[0167]760 (and the device of FIGS. 42) offers a significant advantage over current catheter designs in terms of cost saving and manner in which the access device760 may be utilized. Currently, an introducer is inserted into a vein, and a surgical procedure is performed. After the surgical procedure, the introducer is usually removed and a new catheter is inserted in the vein through a second puncture and sutured onto the skin. The patient is then transported to a recovery room. By using the access device760 of the present invention illustrated in FIG. 43, the procedure can be greatly simplified. The introducer762 is first positioned in the vessel using traditional methods, such as the Seldinger technique. After the introducer762 is used for sampling or infusing fluids,multiple lumen catheter764 is inserted and utilized. Thecatheter764 can then be detached from the introducer762 and removed from the vessel while the introducer762 is left in the vessel, and the introducer762 now functions as a catheter. Thus, after the surgical procedure, the introducer762 does not have to be removed from the vessel and a new catheter does not have to be inserted through a second puncture.

FIGS. 44A and 44B illustrate a multiple[0168]

lumen access device

780 having anintroducer782 connected to a triplelumen junction housing784 by amulti-function adapter786aand786b. Instead of the elongated sheath as in the previous two embodiments, thejunction housing784 includes a shorthollow obturator788 that serves to hold open a hemostasis valve in a hub790 of theintroducer782. The three lumens within thejunction housing784 communicate with the lumen of theobturator788 to deliver fluids to the introducer lumen.

FIGS. 45A and 45B illustrate an[0169]

access device

820 having a single lumen introducer822 connected to a multiplelumen junction housing824 by a threadedfemale adapter826 andmale luer connection828. Adevice valve830 in thejunction housing824 permits insertion of various devices into a vessel via the introducer822 at the same time that various fluids are infused throughextension tubes832.

FIGS. 46A and 46B illustrate an access device[0170]840 similar to theaccess device820 illustrated in FIG. 45 and includes the additional feature of a smalldiameter catheter tube842 extending from a distal end of ajunction housing844. Thecatheter tube842 functions as an infusion lumen for one of theextension tubes846, while the space between thecatheter tube842 and asingle lumen introducer848 functions as a device lumen. Again, thejunction housing844 is attached to theintroducer848 with a threadedadapter850.

Introducer Within Introducer Combination[0171]

A multiple lumen access to the body through a single patient entrance site may also be accomplished by using a plurality of elongated sheaths and implements, such as introducers, obturators or catheters, inserted coaxially within each other to form multiple independent lumens. FIGS. 47A and 47B, for example, illustrate a multi-lumen access device[0172]860 comprising a first single-lumen introducer862 telescopically received within a second single-lumen introducer864. The first introducer862 includes asingle lumen sheath866 having anopening868 at its distal end and connected to an introducer valve housing870 at its proximal end. Within the introducer valve housing, a duck-billed valve or other appropriate valves may be provided to seal the lumen from the exterior. The introducer valve housing870 may include a sideport extension tube872 terminating in ahub874 for attaching to infusion fluid sources. The second elongated implement, for example, anintroducer864 includes asingle lumen sheath876 connected to the distal end of anintroducer valve housing878. Theintroducer valve housing878 also may include a side port extension tube880 terminating in ahub882 for attaching to infusion fluid sources, and thesheath876 may include an opening884 towards a distal end thereof to allow exit of fluid which has been introduced through the side port extension tube880.

As shown in FIG. 47B, the[0173]

sheath

866 of the first introducer862 is sized to fit coaxially through theintroducer valve878 and lumen of thesecond introducer864. Thedistal opening868 of thefirst introducer sheath866 may extend beyond the distal end of thesecond introducer sheath876. In addition, at least one of the lumens formed by the placement of introducer862 coaxially within theintroducer864 is capable of passing a supplemental catheter. By way of example and not limitation, one such catheter has an outside diameter sized about 4 French or more. In one exemplary application of FIG. 47B, fluid 1 (for example, medicine 1) may be introduced through thehub882 and may exit the device through the opening884 while fluid 2 (for example, medicine 2) may be introduced through thehub874 and exit the device through theopening868. Alternatively, the fit between thesmaller sheath866 andlarger sheath876 may be somewhat loose at the distal end so that fluid introduced thehub882 may pass through an annular space formed therebetween, and through the opening884, as indicated by the arrows886. Bothintroducers862 and864 includemale luer connectors888 on their proximal ends for connecting to a variety of medical implements, including the threaded adapters for attaching multiple lumen catheters as previously described.

The access device[0174]860 offers a significant advantage over known introducers by providing multiple lumen access with only a single patient entrance site. Currently, two introducers are usually inserted into the patient at two different sites if another independent lumen is required. The access device860 of the present invention allows the flexibility to start a procedure with only oneintroducer864, and if another independent lumen is required, an additional introducer862 can be inserted into theintroducer864. It is noted that the access device is not limited to two introducers. For example, a combination of three or more introducers may be coaxially configured if additional independent lumens are required.

Also, as will be understood by those skilled in the art, at least one of the single lumen introducers that is coaxially inserted into another single lumen introducer may be made from a flexible deformable material. As a result, the wall forming the sheath of such insertable introducer will also form at least one of the multiple lumens and will be movable upon differential changes in pressure across the wall. This follows from the principles described earlier with respect to extruded multiple lumen sheaths, including the descriptions related to FIGS.[0175]3A-B,11A-C,12 and17. For instance, thelarger introducer sheath876 may be rigid, while thesmaller introducer sheath866 may be flexible or pliable. If a large amount of fluid is infused throughlarger introducer hub882, the space around thesmaller sheath866 experiences and increase in pressure and the sheath may buckle inward to accommodate the larger flow. In one embodiment, a portion of the inside introducer may be rigid and some portion may be flexible, for example only the distal tip of the smaller introducer is rigid to permit insertion through the larger introducer.

MLADS Formed with Obturators within Introducers[0176]

Another alternative embodiment of the present invention forms multi-lumen access device by a combination of a single lumen catheter or introducer with a solid or hollow obturator. FIGS. 48A and 48B illustrate a multi-lumen access device[0177]900 comprising an elongated implement, for example amulti-channel obturator902, inserted into single lumen sheath orcatheter904. Theobturator902 includes asheath906 having adevice lumen908 and, in one preferred embodiment, three evenly circumferentially arrangedlongitudinal ribs910 extending radially from a proximal end to a distal end of thesheath906. Any number of the radially extending ribs is within the scope of the present invention. Similarly, the ribs does not have to be arranged evenly circumferentially. A hemostasis valve912 (within housing) is connected to the proximal end of thesheath906. Thecatheter904 includes asingle lumen sheath914 connected to a hemostasis valve916 (within housing) with threeaccess ports918 for infusion of fluids.

When the[0178]

obturator

902 is inserted into thecatheter904, as shown in FIG. 48B, theribs910 contact the inner wall of thecatheter sheath914 and form three (or any other desired number)auxiliary lumens920. Eachauxiliary lumen920 communicates with thecorresponding access port918 of thecatheter904. To provide a liquid tight seal at the interface between theribs910 and inner wall of thecatheter sheath914, theobturator sheath906 is made from a sufficiently rigid material and is sufficiently sized while thecatheter sheath914 is made from a sufficiently resilient material. Thus, the access device900 has multiple independent fluid entries and multiple independent lumens. In addition, the obturator may be used as a fluid delivery lumen by having an obturator without a hemostasis valve. The multi-lumen access device900 should have at least twoauxiliary lumens920, and preferably three, though other numbers of lumens are also within the scope of the present invention.

One of the advantages of the access device[0179]900 over known introducer products is that it provides greater flexibility of use and eliminates the need for a central venous catheter (CVC). The prior art introducer is inserted into the patient; and if another independent lumen is required, a CVC is usually inserted into the patient. By using the access device900, thecatheter904 is inserted into the patient and if another independent lumen is required as well as a device lumen, theobturator902 may be inserted into thecatheter904 to achieve multi-lumen access with only one patient entrance site.

FIG. 49 illustrates another[0180]

multi-lumen access device

930 which is similar to the access device900 shown in FIGS. 48A and 48B with the exception that anobturator932 has twoaccess ports936 for infusion of fluids, and asingle lumen catheter934 has only oneaccess port938. This arrangement allows all or some of the fluid to be introduced via theobturator932 instead of thecatheter934. The remaining elements of theaccess device930 are not discussed because they are essentially the same as the elements shown in FIGS. 48A and 48B.

A further alternative MLAD using a solid obturator or solid elongated implement is shown in FIGS. 50A and 50B. In this embodiment, a single lumen catheter or introducer[0181]950 is converted to a multiplelumen access device952 upon combination with an obturator954. Obturator954 comprises a proximal hub956 and anelongated trefoil portion958 that closely fits within asheath960 of the introducer950. Three exemplaryauxiliary lumens962 are thus formed within thesheath960. Threeinfusion ports964 provide access to thelumens962, and any one of the them may be adapted to introduce a device through the introducer950.

FIGS.[0182]51-54 illustrate a still further MLAD embodiment formed using an obturator within an introducer. Specifically, aMLAD970 is formed by the combination of ahollow obturator972 with an introducer974. The obturator includes aproximal hub976 and adistal tube978 having a plurality of outwardly directedribs980. Adistal plug member982 has a diameter the same as therubs980. Theobturator972 defines a hollow through bore extending through theproximal hub976 anddistal tube978. The introducer974 includes aproximal hub986 and distal sheath988, and also defines a hollow bore therethrough that transitions from a larger proximal diameter to a smaller distal diameter at astep990. The sheath988 has a tapereddistal tip992 and anoutlet port994 in one side. A fluid infusion port996 is provided in thehub986.

The[0183]

distal tube

978 closely within the sheath988, as seen in FIG. 52, until theplug member982 abuts theinternal step990. Theribs980 seal against the interior of the bore of the sheath988 and thus three sealed fluid flow channels are formed between theobturator972 and introducer974. Eithermultiple outlet ports994 may be provided, one for each channel, of the obturator may be rotated to place one of the three channels into communication with a single outlet port. Devices or other implements can be inserted through thebore984 while fluid is infused through the channels. Another difference between this embodiment and those previously described is the provision of the tapereddistal tip992 on the introducer974 that facilitates insertion over a dilator and into a vessel.

Having thus described exemplary embodiments of the present invention, it should be noted by those skilled in the art that the disclosures herein are exemplary only and that various other alternations, adaptations and modifications may be made within the scope of the present invention. Accordingly, the present invention is not limited to the specific embodiments as illustrated herein.[0184]