5,489,278
`[11] Patent Number:
`[19]
`Unlted States Patent
`
`Abrahamson
`[45] Date of Patent:
`*Feb. 6, 1996
`
`||||I|||||||l||llIlllllllllIll||lllll||||l|l||||||||l||llllllllllllllllllll
`U8005489278A
`
`[54] CATHETER WITH ELONGATED SIDE
`OPENINGS
`
`.
`Inventor.
`
`-
`$212311), A. Abrahamson, Seattle,
`
`[75]
`
`[73] Assignee: Quinton Instrument Company,
`3091611, WaSh-
`
`[*] Notice:
`
`The term of this patent shall not extend
`beyond the expiration date of Pat. No.
`5,403,291.
`
`[211 App1.N0-:380,779
`
`[22]
`
`Filed:
`
`Jan. 30, 1995
`
`Related U.S. Application Data
`
`[63] Continuation—impart of Ser. No. 101,520, Aug. 2, 1993, Fat.
`N 5 403 291
`0'
`’
`’
`'
`Int. C135 .................................................... A61M 25/00
`[51]
`.
`[52] U.S. Cl.
`
`.. 604/280’ 128,658
`[58] Field of Search
`
`........... 128/658; 604/43,
`604354280432
`
`[56]
`
`References Cited
`
`U.S. PATENT DOCUMENTS
`
`.................................. 604/282
`
`4/1985 Howes .................................... 128/674
`Re. 31,873
`90333 Lee -
`390:177
`11/1912 Ruflin.
`1,045,326
`8/1933 Gerow .
`1,922,084
`9/1939 Agayofi
`2,173,527
`2,175,726 10/1939 Gebauer ,
`2,819,718
`1/1958 Goldman.
`2,936,761
`5/1960 Snyder .................................... 604/282
`3,042,045
`7/1962 Sheridan.
`3:314:430
`4/1967 Alley et a1.
`3,359,974 12/1967 Khalil.
`3,394,705
`7/1968 Abramson .
`3,437,088
`4/1969 Bielinski.
`_
`3,448,739
`6/1969 Stark et a1.
`3 452 756
`7/1969 Harautuneian _
`3,459,188
`8/1969 Roberts .
`3,556,161
`1/1971 Roberts ................................... 138/141
`3,566,874
`3/1971 Shepherd et al.
`.
`
`.
`
`7/1971 Bogoffet a1.
`3,593,713
`8/1971 Balin.
`3,599,620
`3,612,050 10/1971 Sheridan.
`3,726,281
`4/1973 Norton et a1..
`3,746,003
`7/1973 Blake at 211..
`3,799,172
`3/1974 Szpur.
`3,828,767
`8/1974 Spirofl“,
`3 875 938
`4,1975 Mellor.
`3,896,815
`7/1975 Felteleta1..
`3,995,623
`12/1976 Blake et a1,
`.
`4,004,588
`1/1977 Alexander.
`4,100,246
`7/1978 Frisch.
`4,134,402
`1/1979 Mahurkar.
`4,144,884
`3/1979 Tersteegen et a1.
`4,168,703
`9/1979 Kenigsberg ,
`4,180,068
`12/1979 Jacobsen 81,111..
`
`.
`
`(List continued on next page.)
`
`FOREIGN PATENT DOCUMENTS
`2 2
`1
`C ad
`.................................... 604/43
`a
`109 9 7
`an
`“198
`1150122
`7/1983 Canada .
`0036642
`9/1981
`European Pat. 01f.
`0079719
`5/1983 European Pat. Off- -
`0333308
`9/1989 European Pat. Ofl',
`.
`1285953
`7/1962
`France .
`1503959
`111968 France.
`France .
`2285148
`4/1976
`2297640
`8/ 1976
`France .
`2530958
`2/1984
`France .
`2259865
`6/1974 Germany .
`8404043
`10/1984 WIPO .
`
`604/43
`
`8404664 12,1984 WIPO‘
`Primary Examiner—John D. Yasko
`Attorney, Agent, or Finn—Andrew J. Beck; Montgomery W,
`Smith; Richard D. Allison
`
`[57]
`
`ABSTRACT
`
`An elongate catheter having one or more lumens therein and
`at
`least one lumen in flow communication with a side
`opening in the sidewall of the catheter wherein the side
`opening includes at least a first side which is oriented
`diagonally with respect
`to the longitudinal axis of the
`catheter and the first Slde. intersects the septum of the
`catheter to form a Side operung wherein the Size of the area
`Of the. opening IS maximized.
`
`12 Claims, 6 Drawing Sheets
`
`
`
`Page 1
`
`Medtronic Exhibit 1026
`
`Page 1
`
`Medtronic Exhibit 1026
`
`

`

`5,489,278
`
`Page 2
`
`U.S. PATENT DOCUMENTS
`
`313:3 82:53:82? 31"
`159333?
`3/1981 nger.
`4,257,416
`.
`6/1981 Boguc 013.1.
`4,270.535
`7/1981 Malmin ................................... 604/264
`4,276,880
`5/1982 Groshong et a1.
`.
`4,327,722
`5/1983 Uthmann ................................. 604/284
`4,385,631
`
`9/1983 Edclman et a1. .......................... 604/43
`4,403,983
`9/1983 Hamlet et a1.
`.................. 604/280
`4,406,656
`~
`2/1984 Groshong at 211‘
`4,431,426
`4/1984 Mah0rkar .................................. 210/87
`4,443,333
`-- 504/43
`5/1984 Mam“
`4451352
`
`604/230
`8’98“ T1951 """"
`414657432
`11/1984 BaJer.
`4,484,585
`.. 604/43
`1/1985 Uldall .....
`4,493,696
`
`.
`.. 604/43
`9/1985 Sommercom at
`4,543,087
`..................................... 604/282
`10/1985 Rydell
`4,547,193
`4,549,879 10,1985 Groshong et a1“
`4,559,046 12/1985 GIOShOHg et a1_ '
`
`604/43
`4,568,329
`2/1986 Mahurkar
`.. 504/43
`4,583,968
`4/1986 Mahurkar
`.. 604/43
`4,619,643
`10/1986 Bai
`.........
`604/4
`4,623,327
`11/1986 Mahurkar _,
`4,626,240 12/1986 Edclman et a1. .......................... 604/43
`
`
`
`4,643,711
`4,661,110
`4,682,978
`4,692,141
`4,753,640
`4755303
`4,772,268
`4,795,439
`4,808,155
`4,813,429
`4,822,345
`4,863,441
`4,894,057
`4,898,591
`4,934,340
`4,995,865
`
`5’004’455
`5,019,057
`5,057,073
`5,171,216
`5,188,592
`5201.723
`5,221,255
`5,221,256
`
`2/1987 Bates ...................... 604/43
`4/‘987 Forticr ct a1.
`.. 604/256
`
`7/1987 Martin ......
`604/43
`
`9/1987 Mahurkar .
`604/43
`6/ 988 NICh01S Ct 31......
`604/247
`7/ 988 Kawashima etal-
`128/6
`
`.. 604/174
`9/ 988 Bates .....
`
`.. 604/280
`1/ 989 Guest
`
`2/ 989 Mahutkar .
`.. 604/43
`
`
`3/ 939 551161 et a1,
`604/43
`
`4/ 989 Danfonh .............
`604/282
`
`.. 604/264
`9/‘989 Lindsay et 31'
`1/ 990 Howes ................
`604/280
`
`2/‘990 Jang 6131 .......
`604/282
`.
`
`6/ 990 Ebhng et a1.
`128/6
`.
`2/ 991 Gabara ct a1.
`604/43
`.
`
`604/43
`4’ 991 Greenwmd etal‘
`
`.. 604/282
`5/ 991 Tmclgm
`
`10/ 991 M31111! ................. 604/43
`12/ 992 Dasse et a1.
`604/43
`
`2/ 993 Hakki
`604/43
`
`4/ 993 Quinn -------
`.. 604/264
`
`6/ 993 Mahurkar et al.
`604/43
`
`6/ 993 Mahurkar ....................... 604/43
`
`
`
`
`Page 2
`
`Medtronic Exhibit 1026
`
`Page 2
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 1 0f 6
`
`5,489,278
`
`FIG.
`
`I
`
`
`
`
`
`Page 3
`
`Medtronic Exhibit 1026
`
`Page 3
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 2 of 6
`
`5,489,278
`
`
`
`FIG. 5
`
`FIG. 6
`
`49 26
`
`28
`
`24
`
`22
`
`Page 4
`
`Medtronic Exhibit 1026
`
`Page 4
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 3 of 6
`
`5,489,278
`
`FIG.
`
`1 1
`
`62
`
`66
`
`7O
`
`\ 60
`
`64
`
`72
`
`68
`
`FIG. 2B
`
`
`
`
`Page 5
`
`Medtronic Exhibit 1026
`
`Page 5
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 4 of 6
`
`5,489,278
`
`F]G. 12
`
`F10.
`
`13
`
`60
`
`@f
`
`64
`
`FIG.
`
`1 4
`
`62
`
`68\
`
`66
`
`60
`
`64
`
`72 \ '70
`
`FIG. 16
`
`
`
`
`
`86\
`
`Page 6
`
`Medtronic Exhibit 1026
`
`Page 6
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 5 of 6
`
`5,489,278
`
`FIG.
`
`1 7
`
`
`
`
`
`128
`
`116
`
`Page 7
`
`Medtronic Exhibit 1026
`
`Page 7
`
`Medtronic Exhibit 1026
`
`

`

`US. Patent
`
`Feb. 6, 1996
`
`Sheet 6 of 6
`
`5,489,278
`
`FIG. 22
`
`136
`
`
`
`
`Page 8
`
`Medtronic Exhibit 1026
`
`Page 8
`
`Medtronic Exhibit 1026
`
`

`

`5,489,278
`
`1
`CATHETER WITH ELONGATED SIDE
`OPENINGS
`
`This is a eontinuation—in—part of copending application
`08/101,520 filed on Aug. 2, 1993, now U.S. Pat. No.
`5,403,291
`
`5
`
`FIELD OF THE INVENTION
`
`The present invention relates to catheters and more par-
`ticularly to a catheter having one or more lumens therein and
`an elongated and generally slot-shaped side hole extending
`through the sidewall of the catheter.
`
`BACKGROUND OF THE INVENTION
`
`Single or multiple lumen catheters are well known in the
`medical field and are widely used in medical procedures
`such’as hemodialysis or other procedures wherein it is
`desirable to inject or remove fluids through one or more
`lumens of the catheter. For example, in hemodialysis it is
`desirable to introduce blood into a vein or other vessel of a
`patient through a first lumen while simultaneously removing
`a corresponding amount of blood from the patient through a
`second lumen of the catheter. In certain situations, it may
`also be desirable to have a third lumen extending through the
`catheter to allow a medication to be injected therethrough
`without interfering with the operation of the first or second
`lumens.
`
`The currently available single or multiple lumen catheters
`frequently have an opening at the distal end thereof and one
`or more openings or holes along the sidewall of the catheter.
`During hemodialysis, the arterial or intake lumen is used to
`remove blood from the patient. This intake lumen typically
`opens along the sidewall of the catheter. In use, the side
`opening may occasionally become completely or partially
`occluded by the interior wall of the patient’s blood vessel
`when the catheter has been inserted. The complete or partial
`occlusion of the side opening will significantly reduce the
`flow of blood through the intake lumen of the catheter and
`may also damage the interior wall of the patient’s blood
`vessel.
`
`In certain commercially available catheters one or more
`relatively large side openings are used. With these side
`openings it is typically recommended that the flow of fluid
`through the side opening be checked prior to hemodialysis.
`If the side opening is occluded, it is recommended that the
`catheter be rotated or otherwise repositioned. A further
`difficulty with the use of the large single side opening is that
`the side opening may occasionally get caught on the tissue
`or the wall of the blood vessel along the incision during
`insertion. Yet another difficulty with the use of a large single
`side opening is that the catheter may kink or bend at the side
`opening during insertion if the catheter tip meets resistance
`during insertion because the large side opening may weaken
`the column strength of the catheter.
`In other commercially available catheters, as disclosed in
`U.S. Pat. No. 4,543,087 granted to Sommercom et al., a
`plurality of spaced apart side openings are provided so that
`even if one side opening is occluded at least one of the
`remaining side openings may remain open. Another
`approach to solving the problem of occlusion is disclosed in
`U.S. Pat. No. 4,795,439 granted to Guest. In this patent, the
`lumens of the distal portion of the catheter are twisted such
`that the plurality of side openings in the catheter are not
`aligned in a straight line along the distal portion of the
`catheter. A firrther catheter design is shown in U.S. Pat. No.
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`40
`
`50
`
`55
`
`60
`
`65
`
`2
`4,808,155 granted to Mahurkar wherein a blunt distal end is
`provided on the catheter and the shorter intake lumen
`includes a bevel thereon which ends proximally of the return
`lumen.
`
`The use of multiple side openings in a catheter provides
`an increased likelihood that a clot may form along or in one
`or more of the side openings as compared to the likelihood
`of clotting in catheters with a single side opening for each
`lumen. This increased likelihood of clot formation is
`believed to be caused, at least partially, by the presence of
`multiple surfaces between each of the side openings which
`may provide an area of reduced flow in the lumen which
`allows the clot to form thereon. Additionally, it is a common
`practice to perform a heparin flush of the catheter periodi—
`cally to decrease the likelihood of clot formation on the
`catheter. The heparin flush technique is believed to be less
`efiective in removing or preventing clot formation in cath-
`eters with multiple side openings because if one of the side
`openings is occluded by a clot, the heparin will merely flow
`through the side opening which provides the least resistance.
`There is also the possibility that the heparin may be washed
`out of the distal portion of the lumen of the catheter by blood
`which may enter one or more of the proximally located side
`openings to flush the heparin through the lumen and out of
`the catheter through one or more of the distally located side
`openings.
`One final approach to solving the problem of preventing
`occlusion and clot formation involves the use of elongate
`slits as side openings in the catheter. The slits completely
`close the lumen between uses and are opened only upon the
`application of either positive or negative pressure to the fluid
`in the lumen of the catheter. One difficulty with this
`approach is that it requires increased pressure through the
`lumens of the catheter to open the slit openings during use.
`Additionally, if the blood is not completely removed from
`the lumen by the heparin flush, the stagnant flow of fluid in
`the lumen may result in the formation of a clot in the lumen
`which will be difiicult to remove through the slit.
`The present
`invention overcomes the disadvantages
`described above by providing an elongated side opening
`which is preferably oriented diagonally along the distal
`portion of the catheter to retain the column strength of the
`catheter while minimizing the likelihood of occlusion or clot
`formation.
`
`SUMMARY OF THE INVENTION
`
`The present invention is directed to a generally slot-
`shaped side opening for use on a catheter having one or more
`lumens therein. In a preferred form of the present invention,
`the side opening is preferably oriented diagonally along the
`longitudinal axis of the catheter such that one end of the slot
`is oriented distally of the other end of the slot. The end of the
`slot preferably terminates adjacent to the sides of the respec-
`tive surface of the lumen to maximize the open passageway
`for the flow of fluid therethrough. Additionally, the sidewalls
`of the side opening are preferably spaced apart and generally
`parallel to each other to form an elongated and diagonally
`oriented slot which extends around a significant portion of
`the diameter of the catheter.
`
`The preferred form of the catheter of the present invention
`is a dual or triple lumen hemodialysis catheter having at least
`one generally D—shaped lumen therein. The catheter prefer-
`ably includes a blood return or first lumen which extends
`between the proximal end of the catheter and the distal
`opening on the catheter tip which is located at the distal end
`
`Page 9
`
`Medtronic Exhibit 1026
`
`Page 9
`
`Medtronic Exhibit 1026
`
`

`

`5,489,278
`
`3
`of the catheter. The intake or second lumen of the catheter
`preferably extends between the proximal end of the catheter
`and a side opening which is preferably located along the
`distal portion of the catheter and generally proximal to the
`catheter tip.
`An object of the present invention is to provide a side
`opening in the sidewall of a catheter which is shaped and
`oriented to minimize the kinking of the catheter at the side
`opening during insertion.
`Another object of the present invention is to provide a side
`opening in the sidewall of a catheter which is shaped and
`oriented to minimize tunnel tract tissue snag and blood
`vessel wall snag during the insertion or removal of the
`catheter.
`
`Another object of the present invention is to prevent
`clotting by providing a side opening in the sidewall of a
`catheter which is shaped and oriented to be essentially self
`flushing such that external fluid flow may pass directly from
`the proximal side of the side opening to the distal side of the
`side opening without interruption. Yet another object of the
`present invention is to reduce vessel wall occlusion by
`providing a side opening which maximizes the open pas-
`sageway for fluid flow even when a portion of the slot is
`occluded by or sucked against a portion of the vessel wall.
`
`BRIEF DESCRIPTION OF THE DRAWINGS
`
`FIG. 1 is an elevated left side view of a catheter of the
`present invention;
`FIG. 2A is an enlarged elevated front side view of the
`distal portion of the embodiment shown in FIG. 1;
`FIG. 2B is an enlarged elevated front side view of an
`alternate embodiment of the distal portion of the embodi-
`ment shown in FIG. 1;
`FIG. 3 is an enlarged right side view of the distal portion
`of the embodiment shown in FIG. 1;
`FIG. 4 is an enlarged left side view of the distal portion
`of the embodiment shown in FIG. 1;
`FIG. 5 is an enlarged diagrammatic right side view of the
`distal portion of the embodiment shown in FIG. 1, taken
`generally along lines 5—5 of FIG. ZA showing an end View
`of the side opening of the present invention;
`FIG. 6 is an enlarged cross-sectional view of the distal
`portion of the embodiment shown in FIG. 1, taken generally
`along lines 6—6 of FIG. 2A;
`FIG. 7 is a cross-sectional view of the embodiment shown
`in FIG. 1 taken generally along lines 7—7 of FIG. 1;
`FIG. 8 is a cross-sectional View of the embodiment shown
`in FIG. 1 taken generally along lines 8—8 of FIG. 1;
`FIG. 9 is an elevated side view of a triple lumen catheter
`constructed in accordance with the present invention;
`FIG. 10 is an enlarged elevated side view of the distal
`portion of the embodiment shown in FIG. 9;
`FIG. 11 is an enlarged cross-sectional view of the embodi-
`ment shown in FIG. 9 taken generally along lines 11—11 of
`FIG. 10;
`FIG. 12 is an enlarged cross-sectional view of the embodi-
`ment shown in FIG. 9 taken along lines 12—12 of FIG. 10;
`FIG. 13 is an enlarged end view of the catheter shown in
`FIG. 9 taken generally along lines 13—13 of FIG. 10;
`FIG. 14 is an enlarged cross—sectional view of an alternate
`form of a triple lumen catheter constructed in accordance
`with the present invention similar to the view shown in FIG.
`11;
`
`10
`
`15
`
`20
`
`25
`
`30
`
`35
`
`4O
`
`45
`
`50
`
`55
`
`60
`
`65
`
`4
`FIG. 15 is an elevated side view of a single lumen catheter
`constructed in accordance with the present invention;
`FIG. 16 is an elevated side view of an alternate form of
`the side opening of the present invention;
`FIG. 17 is an elevated side view of the distal portion of
`another catheter constructed in accordance with the present
`invention;
`FIG. 18 is an elevated right side view of the distal portion
`of the catheter constructed in accordance with FIG. 17;
`FIG. 19 is an enlarged cross-sectional view of the embodi-
`ment shown in FIG. 17 taken generally along lines 19—19
`of FIG. 17;
`
`FIG. 20 is an enlarged cross-sectional view of the embodi-
`ment shown in FIG. 17 taken along lines 20—20 of FIG. 17;
`FIG. 21 is an enlarged cross—sectional View of the embodi-
`ment shown in FIG. 17 taken along lines 21—21 of FIG. 17;
`FIG. 22 is an elevated top view of the distal portion of
`another catheter constructed in accordance with the present
`invention; and
`FIGS. 23A and 23B are enlarged right and left side views,
`respectively, of the embodiment shown in FIG. 22.
`
`DESCRIPTION OF THE PREFERRED
`EMBODIMENTS
`
`As shown in the drawings, the preferred form of the
`overall catheter assembly 10 of the present invention is
`generally similar to the dual lumen hemodialysis catheter
`shown in U.S. Pat. No. 4,583,968 granted to Mahurkar on
`Apr. 22, 1986. The catheter assembly 10 generally includes
`an elongate and slightly oval-shaped body portion 12 having
`a tip member 14 on the distal end thereof and a Y-shaped
`connector hub 16 on the proximal end thereof. As shown in
`FIG. 1, the proximal end of the Y-connector includes exten-
`sion members 18 and 20 thereon. As used herein, the term
`“proximal” is intended to refer to the end or portion of a
`member which is normally oriented or positioned away from
`the patient while the term “distal” refers to the end or portion
`of a member in use which is nearest to the patient. Although
`the preferred form of the present invention is described
`herein with respect to multiple lumen catheters, it is intended
`that the present invention may also be used with nearly any
`catheter having one of more lumens therein including angio-
`graphic or various diagnostic catheters.
`The body portion 12 of the preferred embodiment of the
`catheter assembly 10 is hollow except for a generally flat,
`longitudinal septum 22 which divides the interior of the
`hollow cylinder into two preferably parallel lumens 24 and
`26, with each lumen, 24 and 26, having a generally
`D-shaped cross section as shown in FIG. 7. As illustrated by
`the arrows in FIG. 6, the lumen 24 is the blood intake or
`arterial
`lumen, and the lumen 26 is the blood return or
`venous lumen.
`
`At the distal end of the catheter assembly 10, the exterior
`surface of the body portion 12 merges into the smoothly
`tapered conical tip member 14. On the inside of the body
`portion 12, the blood return lumen 26 extends longitudinally
`all the way through the tip member 14, bending slightly as
`it passes through the tip member 14 so that it opens at distal
`opening 28 near the center of the distal end of the tip
`member as can be seen in FIG. 6. Within the tip member 14
`the preferred cross~seetional shape of the lumen 26 gradu-
`ally changes from D—shaped at the proximal end of the tip
`member 14 to circular at the distal end of the tip member 14
`at the distal opening 28 as shown in FIGS. 7 and 8. The
`
`Page 10
`
`Medtronic Exhibit 1026
`
`Page 10
`
`Medtronic Exhibit 1026
`
`

`

`5
`
`6
`
`5,489,278
`
`cross-sectional diameter of the distal opening 28 is prefer—
`ably maximized so that the blood retum lumen 26 may not
`require a side opening therein. In order to provide longitu-
`dinal spacing between the distal openings of the two lumens
`24 and 26, the blood intake lumen 24 is terminated at side
`opening 30 in the sidewall of the catheter as described more
`fully below.
`At the proximal end of the catheter 10, the two D—shaped
`lumens 24 and 26 connect to a Y-shaped connector hub 16
`which forms two internal passageways communicating with
`the proximal ends of the catheter lumens 24 and 26. The
`passageways of the connector hub 16 diverge from each
`other and assume a circular cross section as they extend
`toward the proximal end of the connector hub 16. The
`passageways may also increase in cross-sectional area as
`they extend toward the proximal end of the connector hub
`16. The connector hub 16 is preferably molded in place on
`the end of the catheter, using mold core pins to form the hub
`passageways. Alternatively, the walls of the catheter lumens
`24 and 26 may be expanded at the proximal end of the body
`portion 12 of the catheter to fit over the corresponding
`portions of a preformed connector hub 16 with the inside
`walls of the catheter lumens 24 and 26 being bonded to the
`mating walls of the connector hub 16.
`To facilitate connection of the connector hub 16 to the
`conventional tubes leading to a dialysis unit, and also to
`accommodate a pair of clamps 42 and 44 for opening and
`closing the blood intake and return lumens 24 and 26, the
`connector hub 16 is fixedly attached to the pair of tubular
`extension members 18 and 20 as shown in FIG. 1. These
`extension members 18 and 20 are relatively soft and flexible
`so that they may be manipulated as needed and also easily
`closed by the pressure of the clamps 42 and 44. As shown
`in FTG. 1, the preferred form of the extension members 18
`and 20 is pre-curved or bent to facilitate the positioning of
`the extension members 18 and 20 along the body of the
`patient when the catheter assembly 10 is inserted therein.
`The clamps 42 and 44 serve as on-ofl valves for controlling
`the flow of blood between the catheter assembly 10 and the
`dialysis unit. At the proximal end of the extension members
`18 and 20, a pair of luer connectors are formed or bonded as
`integral parts thereof. The luer connectors serve as a means
`for coupling the proximal ends of the extension members 18
`and 20 to a plurality of flexible tubes (not shown) which lead
`to the extracorporeal or hemodialysis treatment unit.
`As shown in FIGS. 2A and 3—5, the preferred embodiment
`of the present invention includes a generally elongated and
`diagonally oriented side opening 30 formed in the sidewall
`of the catheter. Although the side opening 30 is preferably
`laser cut into the sidewall of the catheter, it is anticipated that
`it may be formed in the sidewall of the catheter by various
`other currently available methods.
`FIG. 2B shows an alternate form of the present invention
`wherein like numbers have been added to like members.
`
`As shown in FIG. 2A, the side opening 30 is preferably
`formed as a slot-shaped opening having a first side 46 which
`is positioned proxirnally of a second side 48 such that the
`side opening 30 is not perpendicular to the longitudinal axis
`of the catheter. In the preferred form of the present embodi-
`ment, the side opening 30 is oriented at an angle of about 30
`degrees with respect to the longitudinal axis of the catheter
`although it is anticipated that this could be nearly any angle
`including a side opening wherein the sides and ends of the
`side opening 30 are not parallel with respect to each other.
`Additionally,
`the first and second sides 46 and 48 are
`preferably formed to end generally at the surface of the
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`septum 22 so that the cross-sectional area of the side opening
`30 is maximized. The side opening 30 also includes distal
`and proximal ends 50 and 52, respectively, which are spaced
`apart from each other a predetermined distance as shown in
`FIGS. 2A and 2B. The distance between the distal and
`proximal ends, 52 and 54,
`is dependent on a number of
`factors including the overall diameter of the catheter, the
`number of lumens in the catheter and its intended use. The
`first and second sides 46 and 48 and the distal and proximal
`ends 50 and 52 of the side opening 30 are preferably oriented
`along the sidewall of the catheter such that the tissue along
`the incision as well as the wall of the blood vessel are
`supported by at least one of the distal or proximal sides 46
`and 48 of the side opening 30 during the insertion or removal
`of the catheter, as best shown in FIG. 3. This minimizes the
`depth with which the tissue or blood vessel wall is able to
`enter the side opening 30 thereby minimizing the likelihood
`that the catheter will be caught on or otherwise will be hung
`up on the tissue or blood vessel wall during the insertion of
`the catheter.
`
`As shown in FIG. 3, it is also preferred that the angle 54
`formed by intersection of the first side 46 and the distal end
`50 of the side opening 30 is relatively shallow. Additionally,
`as shown in FIG. 4, the angle 56 formed by the intersection
`of the second side 48 and the proximal end 52 of the side
`opening 30 is also relatively shallow. Therefore, when the
`catheter is inserted into the patient, the tissue initially passes
`over the distal end 50 of the side opening 30 and contacts the
`intersection of the distal end 50 and the first side 46 and is
`lifted up or supported along the gradually inclined surface
`found on this portion of the side opening 30. Additionally,
`the physician may occasionally twist the catheter during
`insertion into the patient. With the preferred orientation of
`the side opening 30 of the present invention,
`the side
`opening 30 may essentially be threaded into the incision of
`the patient as the physician rotates the catheter along the
`orientation of the side opening 30 during the insertion
`procedure.
`When the catheter is removed from the patient, the tissue
`initially passes over the proximal end 52 of the side opening
`30 and contacts the intersection of the second side 48 and the
`proximal end 52 of the side opening 30 so that the tissue is
`lifted up or supported along the gradually inclined surface
`formed on this portion of the side opening 30. The incline
`angles of the side opening 30 are at least partially controlled
`by the slot angle and corner radius at the intersection of the
`distal and proximal ends 50 and 52 and the first and second
`Sides 46 and 48, and an example of this is shown in FIG. 5.
`Additionally,
`the spacing between the first and second
`sides 46 and 48 and the orientation of the side opening 30
`along the catheter is optimized to yield the greatest tube
`stiffness in the slot area to minimize kinking and reduce the
`force necessary to insert or remove the catheter from the
`patient. The slot opening 30 is also shaped and oriented
`along the catheter to optimize the flow of fluid therethrough
`at a full range of flow rates and pressures while minimizing
`the likelihood of occlusion of the side opening 30 against the
`wall of the blood vessel. In the preferred embodiment of the
`present invention, the likelihood of complete occlusion of
`the side opening 30 by the wall of the blood vessel is
`minimized because the side opening extends along approxi-
`mately one-half of the external surface or nearly 180 degrees
`of the circumference of the catheter so that, even if the side
`opening 30 were positioned against the wall of the blood
`vessel, it is unlikely that the entire side opening 30 will be
`occluded by the wall of the blood vessel.
`As shown best in FIG. 6, the blood intake lumen 24
`terminates at the side opening 30. The area of the catheter
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`5,489,278
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`7
`which is distal to the blood intake lumen 24 is preferably
`closed by a plug material 49, as shown in FIG. 6, which is
`molded as part of or inserted into the blood intake lumen 24
`and is adhesively or otherwise fixedly connected to the distal
`end portion of the catheter. The plug material 49 preferably
`fits flush with the distal surface of the side opening 30 to
`prevent the formation of a reduced or stagnant flow area at
`the distal end of the intake lumen 24. Therefore, as the side
`opening 30 is flushed by the flow of blood passing between
`the proximal end 52 and distal end 50,
`the blood also
`contacts the smoothsurface formed by the second side 48
`and plug material 49. The tip member 14 may be a pre-
`formed member which may be made out of a variety of
`materials including polyurethane or polyvinyl chloride.
`FIGS. 7 and 8 are illustrative of the preferred shape of the
`blood return lumen 26 proximally and distally of the side
`opening 30.
`As shown in FIGS. 9—14, a side opening 58 in accordance
`with the present invention may also be used on triple lumen
`catheters; including a triple lumen catheter 60 of the type
`described herein. Like numbers have been added to like
`members which are more fully described above. In these
`embodiments the catheter includes a septum 62 which forms
`first, second and third lumens, 64, 66 and 68 respectively. If
`the catheter 60 is used for hemodialysis, the first and second
`lumens 64 and 66 preferably function similar to the blood
`return and blood intake lumens 26 and 24 of the embodiment
`described above. FIG. 9 shows the side opening 58 of the
`present embodiment in communication with the second
`lumen 66. As shown in FIGS. 11 and 14, the first and second
`lumens 64 and 66 are formed by first and second wall
`portions 70 and 72 of the septum 62. In these embodiments,
`the first wall portion 70 is generally straight and extends
`inwardly from the sidewall of the catheter 60. The second
`wall portion 72 is preferably bent (FIG. 11 or 14) such that
`the ends of the second wall portion 72 contact the sidewall
`of the catheter at an angle greater than or equal to ninety
`degrees to reduce the likelihood of a stagnant flow area
`within the first and second lumens 64 and 66 of the catheter
`60.
`
`The side opening 58 of this embodiment preferably
`extends about 160 degrees around the circumference of the
`catheter. The side opening 58 includes first and second sides
`74 and 76 which are located adjacent to the intersection of
`the first and second wall portions 70 and 72 of the septum
`62 and the sidewall of the catheter 60. As with the prior
`embodiment, the first side 74 is preferably located proxi-_
`mally of the second side 76 of the side opening 58 and is also
`spaced apart from the second side 76 and at a preferred angle
`of about 30 degrees from the longitudinal axis of the catheter
`60.
`
`The side opening 58 also includes distal and proximal
`ends 78 and 80 which are spaced apart from each other and
`extend between the first and second sides 74 and 76 to form
`an elongated slot-shaped member in the sidewall of the
`catheter 60. As with the prior embodiment and described
`more fully above, the angles formed between the ends and
`sides of the side opening are optimized to facilitate the
`operational characteristics of the catheter 60 during its
`insertion, use and removal. The side opening 58 in this
`embodiment is preferably about 1.3 inches from the distal
`end of the catheter. The side opening 82 for the third lumen
`68 is located about midway between the side opening 58 and
`the distal end of the catheter. The side opening 82 of this
`embodiment is preferably a conventional hole although an
`elongated slot-shaped opening which may extend about 40
`degrees around the circumference of the catheter 60 between
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`the intersection of the ends of the second wall portion 72
`with the sidewall of the catheter 60 may also be used. A
`slot-shaped side opening 82 would be preferably diagonally
`oriented along the sidewall of the catheter and include first
`and second ends and distal and proximal sides which would
`be similar to those described above with respect to side
`openings 30 and 58. The slot-shaped side opening 58 is
`preferably laser cut into the sidewall of the catheter 60
`although, due to the relative size of side opening 82, this side
`opening 82 may be punched or otherwise formed as a round
`or otherwise shaped opening without significantly afiecting
`the performance of the present embodiment.
`FIG. 15 shows a further embodiment of the present
`invention wherein a single lumen catheter 84 preferably
`includes at least one generally slot-shaped side opening 86
`thereon. In the preferred form of this embodiment, the side
`opening 86 extends about 180 degrees around the circum-
`ference of the catheter 84 and is diagonally oriented with
`respect
`to the lo