Dual-Lumen Catheter Assembly

Abstract

A catheter assembly includes a shaft with two non-communicating lumens for simultaneous inflow and outflow of fluids from a vein. A return lumen extends to an outlet assembly at the tip. A draw lumen includes an inlet assembly, proximally of the outlet assembly, with multiple openings to avoid blockage causing pressure elevation due to suction. The draw lumen has a larger crescent-shape profile while the return lumen has a smaller, circular profile within the arms of the crescent shape.

Claims

1. A dual-lumen catheter assembly, comprising: a dual-lumen catheter shaft assembly having an exterior, comprising a distal tip; a draw lumen; a return lumen; and an interlumen wall between the draw lumen and the return lumen; a return outlet assembly connecting the return lumen to the exterior; and a draw inlet assembly connecting the draw lumen to the exterior; and wherein the return outlet assembly is adjacent to the tip; wherein the draw inlet assembly is proximal of the return outlet assembly; and wherein the draw inlet assembly comprises a plurality of inlet holes.

2. The catheter assembly of claim 1: the draw inlet assembly comprising a main inlet and a first side hole and a second side hole.

3. The catheter assembly of claim 2, further comprising the main inlet being substantially larger than said side holes.

4. The catheter assembly of claim 2: the main inlet and the first side hole separated by a first longitudinal inlet spacing of about 3.0-4.5 mm; the main inlet and the second side hole separated by a second longitudinal inlet spacing; and said first and second longitudinal inlet spacing being different.

5. The catheter assembly of claim 4, further comprising: at least one of said side holes separated from the main inlet angularly by about 40-45 degrees.

6. The catheter assembly of claim 2, further comprising: at least one of said side holes separated from the main inlet angularly by about 30-55 degrees.

7. The catheter assembly of claim 6, further comprising: each of said side holes separated from the main inlet angularly in different directions.

8. The catheter assembly of claim 1, the catheter shaft assembly further comprising: a 16G shaft body; the shaft body comprising the draw lumen and the return lumen; and wherein the draw lumen is at least 18G and the return lumen is at least 20G.

9. The catheter assembly of claim 8, the shaft body further comprising: a dual-lumen section; and a single-lumen section distal of the dual-lumen section; wherein the draw lumen has a crescent-shaped profile and the return lumen has a circular profile.

10. The catheter assembly of claim 1, further comprising the catheter shaft assembly being flexible.

11. The catheter assembly of claim 1, the draw lumen having a crescent-shaped profile and the return lumen having a circular profile.

12. The catheter assembly of claim 1, the catheter shaft assembly further comprising: a shaft body; the shaft body comprising exterior walls about the draw lumen and the return lumen; the shaft body comprising an interlumen wall between the draw lumen and the return lumen; wherein the draw lumen has a crescent-shaped profile and the return lumen has a circular profile.

13. The catheter assembly of claim 1, the catheter shaft assembly further comprising: a shaft body, comprising a dual-lumen section; and a single-lumen section, the single lumen section being distal of the dual-lumen section; and a tapered section distal of the single-lumen section; and the distal tip being distal of the shaft body.

14. The catheter assembly of claim 13, the single-lumen section having substantially the same diameter and profile along its length as the dual-lumen section.

15. The catheter assembly of claim 13, the tapered section terminating in the distal tip.

16. The catheter assembly of claim 1, further comprising: a Y-body proximal of the catheter shaft assembly; the Y-body comprising a draw section and a return section; the draw section comprising a Y-body draw lumen fluidly connected to the draw lumen of the catheter shaft assembly; the return section comprising a Y-body return lumen fluidly connected to the return lumen of the catheter shaft assembly; wherein the Y-body return lumen is aligned in a straight line with the return lumen of the catheter shaft assembly to permit a needle to be inserted inside both.

17. The catheter assembly of claim 16, further comprising: a retractable needle inserted within the Y-body return lumen and the return lumen of the catheter shaft assembly.

18. The catheter assembly of claim 1, the return outlet assembly comprising: a main hole; and a plurality of extra fenestrations; the main hole being located at the distal tip; and the extra fenestrations being located proximally of the main hole.

19. The catheter assembly of claim 18, the extra fenestrations being located about 2-6 mm distally of the main hole.

20. The catheter assembly of claim 1, further comprising a draw/return spacing between the return outlet assembly and the draw inlet assembly of about 18-22 mm.

21. The catheter assembly of claim 1, further comprising a draw/return spacing between the return outlet assembly and the draw inlet assembly of at least about 20 mm.

22. The catheter assembly of claim 1, further comprising: a shaft body, the shaft body comprising a dual-lumen section; and a single-lumen section, the single lumen section being distal of the dual-lumen section; and wherein the single-lumen section has substantially the same diameter and profile along its length as the dual-lumen section; and the draw lumen having a crescent-shaped profile and the return lumen having a circular profile; and the draw inlet assembly further comprising a main inlet and a first side hole and a second side hole; the main inlet and the first side hole separated by a first longitudinal inlet spacing; the main inlet and the second side hole separated by a second longitudinal inlet spacing; and said first and second longitudinal inlet spacing being different; and each of said side holes separated from the main inlet angularly in different directions.

23. A method of using a dual-lumen catheter assembly for draw and return of fluids from a vein, comprising: drawing fluids from an exterior of a dual lumen catheter shaft assembly via a plurality of inlet holes of a draw inlet assembly connecting a draw lumen to the exterior; and returning fluids to the exterior of the catheter shaft assembly via a return outlet assembly connecting a return lumen to the exterior; the returning step occurring adjacent to a distal tip of the catheter assembly; and the drawing step occurring proximally of said drawing step.

24. The method of claim 23, further comprising: maintaining recirculation of the fluids below 20%.

25. The method of claim 23, further comprising: maintaining recirculation of the fluids between about 10%-15%.

26. The method of claim 23, further comprising: carrying out an apheresis treatment on the fluids after the drawing step and before the returning step.

27. The method of claim 23: the catheter assembly comprising a 16G shaft body; the shaft body comprising the draw lumen and the return lumen; and wherein the draw lumen is at least 18G and the return lumen is at least 20G.

28. The method of claim 23, the draw inlet assembly further comprising a main inlet and a first side hole and a second side hole.

29. The method of claim 28, the main inlet and the first side hole separated by a first longitudinal inlet spacing; the main inlet and the second side hole separated by a second longitudinal inlet spacing; and said first and second longitudinal inlet spacing being different.

30. The method of claim 28, at least one of said side holes separated from the main inlet angularly by about 30-55 degrees.

31. The method of claim 23, the draw lumen having a crescent-shaped profile and the return lumen having a circular profile.

32. The method of claim 23, the drawing step further comprising said drawing of fluids occurring at a draw/return spacing of about 18-22 mm.

33. The method of claim 23, the catheter shaft assembly further comprising: a shaft body; the shaft body comprising exterior walls about the draw lumen and the return lumen; the shaft body comprising an interlumen wall between the draw lumen and the return lumen; wherein the draw lumen has a crescent-shaped profile and the return lumen has a circular profile.

34. The method of claim 23, further comprising: advancing a Y-body return lumen of a Y-body and the return lumen of the catheter shaft assembly over a retractable needle; said Y-body return lumen aligned in a straight line with the return lumen of the catheter shaft assembly.

35. The method of claim 23, further comprising the catheter shaft assembly being flexible.

36. A method of using a dual-lumen catheter assembly for draw and return of fluids from a vein, comprising: drawing fluids by a main draw flow path from the exterior of a dual-lumen catheter assembly into a draw lumen; the drawing step further comprising drawing fluids by one or more secondary flow paths from the exterior to the draw lumen; and returning fluids to the exterior of the catheter assembly distally of the drawing steps and adjacent to a distal tip of the catheter assembly.

37. The method of claim 36, further comprising the step of maintaining recirculation of the fluids below 20%.

38. The method of claim 36: the catheter assembly comprising a 16G shaft body; the shaft body comprising the draw lumen and the return lumen; and wherein the draw lumen is at least 18G and the return lumen is at least 20G.

39. The method of claim 36, the drawing step further comprising: drawing fluids by a first secondary flow path separated by a first inlet spacing from the main flow path; and drawing fluids by a second secondary flow path separated by a second inlet spacing from the main flow path; said first and second inlet spacing being different.

40. The method of claim 36, the drawing step further comprising: drawing fluids by a first secondary flow path separated angularly by about 30-55 degrees from the main flow path; and drawing fluids by a second secondary flow path separated angularly by about 30-55 degrees in the opposite direction from the main flow path.

41. The method of claim 34, the draw lumen having a crescent-shaped profile and the return lumen having a circular profile.

42. The method of claim 34, the drawing step further comprising said drawing step occurring at a draw/return spacing of about 18-22 mm.

Description

BRIEF DESCRIPTION OF THE FIGURES

[0033] FIG. 1A is a left side view of an embodiment of a catheter assembly.

[0034] FIG. 1B is a top view of the device in FIG. 1A.

[0035] FIG. 2 is a front, left, top oblique view of an embodiment of a catheter assembly omitting the needle and some connector pieces.

[0036] FIG. 3A is a top view of a portion of an embodiment of a catheter assembly.

[0037] FIG. 3B is a left side view of the device in FIG. 3A.

[0038] FIG. 3C is a distal end view of the device in FIG. 3A.

[0039] FIG. 3D is a proximal end view of the device in FIG. 3A.

[0040] FIG. 3E shows a section view along line A—A from FIG. 3B.

[0041] FIG. 3F shows a section view along line B—B from FIG. 3B.

[0042] FIG. 3G shows a section view along line C—C from FIG. 3D.

[0043] FIG. 4A shows detail of a portion of an embodiment of a catheter shaft.

[0044] FIG. 4B shows detail of a portion of an embodiment of a catheter shaft.

[0045] FIG. 4C shows detail of a portion of an embodiment of a catheter shaft.

[0046] FIGS. 5A-5C show an embodiment of the process of vein access using an embodiment of a catheter assembly in a sectioned view.

[0047] FIG. 6 shows the blood flow in a vein with an embodiment of the catheter assembly in use after vein access.

[0048] FIG. 7A is a top view of a portion of an embodiment of a catheter assembly.

[0049] FIG. 7B is a left side view of the device in FIG. 7A.

[0050] FIG. 8 shows an embodiment of a catheter assembly in an embodiment of the process of vein access in a sectioned view.

[0051] FIG. 9A shows a section view of the shaft assembly of an alternative embodiment of a catheter assembly.

[0052] FIG. 9B shows a section view of the shaft assembly of an alternative embodiment of a catheter assembly.

[0053] FIG. 9C shows a section view of the shaft assembly of an alternative embodiment of a catheter assembly.

[0054] FIG. 10 shows steps of a process for carrying out an embodiment of the invention.

[0055] FIG. 11 shows steps of a process for carrying out an embodiment of the invention.

DETAILED DESCRIPTION OF THE INVENTION

[0056] Referring to FIGS. 1A, 1B, 2, and 3A-3G, in an embodiment of the invention, as described in detail below, dual-lumen catheter assembly 1 includes dual-lumen catheter shaft 10, Y-body 60, and needle 70, as well as draw tubing 91, return tubing 92, female connectors 93, and male cap 94. Removing cap 94 and needle 70 permits connection to apheresis machine 96 (not depicted).

[0057] Dual-lumen catheter shaft 10 includes exterior 11, distal tip 13, shaft body 20, draw inlet assembly 40, and return outlet assembly 50. Exterior 11 of shaft 10 is, in use, exposed to interior 3 of vein 2 and fluid flow 7 of fluids 6 therein (see FIGS. 6A & 6B). Shaft body 20 is at the proximal end of dual-lumen catheter shaft 10, while distal tip 13 is at the distal end. Shaft body 20 includes tapered section 21 at its distal end, and proximal thereof, dual-lumen section 31, having circular or substantially circular profile 32, and proximal of dual-lumen section 31 single-lumen section 33, having circular or substantially circular profile 34. Shaft body 20 also includes, within dual-lumen section 31, draw inlet assembly 40, draw lumen 24 having crescent-shaped profile 24, and return lumen 26 having circular profile 27, and interlumen wall 28 therebetween, and exterior walls 29 therearound. Shaft body 20 also includes, within single-lumen section 31, return lumen 26 having circular profile 27 and exterior walls 29 therearound. Shaft body 20 also includes, within tapered section 21, return outlet assembly 50, and return lumen 26 therethrough.

[0058] FIG. 3E shows, in section, crescent-shaped profile 25, circular profile 27, and interlumen wall 28. FIGS. 9A-9C show, in section, circular profile 27, and interlumen wall 28, with alternative profiles 25′, 25″ and 25′″.

[0059] Referring to FIGS. 1A, 1B, 2, and 3A-3G, in an embodiment, draw inlet assembly 40 includes main inlet 41, first side hole 42, and second side hole 43. Draw inlet assembly 40 is at the distal end of dual-lumen section of shaft body 20. Draw inlet assembly 40 has draw inlet assembly length 49.

[0060] Main inlet 41 may be about 1.0-1.5 mm in diameter, or about 1.0-1.5 mm by 2.5-3.0 mm in size, or about 1.24 mm by about 2.89 mm. Side holes 42, 43, may be 0.3-0.7mm, or about 0.52 mm or 0.5 mm, in diameter. Main inlet 41 connects draw lumen 24 to exterior 11 of dual-lumen catheter shaft assembly 10. Main inlet 41 forms a main draw flow path into draw lumen 24.

[0061] Side holes 42, 43 each have a longitudinal inlet spacing between themselves and main inlet 41. First side hole 42 has first longitudinal inlet spacing 44 of about 3.0-4.5 mm, about 3.74 mm, or about 4.5 mm, (edge-to-edge) from main inlet 41. Second side holes 43 has side hole spacing 46 of about 1.0-2.0 mm, or about 1.48 mm, (edge-to-edge) from first side hole 42, making second longitudinal inlet spacing 45 of about the sum of side hole spacing 46 and first longitudinal inlet spacing 44. Side holes 42, 43 each also have angular spacing or offset between themselves and main inlet 41. First side hole 42 has first angular separation 47 of about 30-55 degrees, about 40-45 degrees, or about 45 degrees from main inlet 41. Second side hole 43 has second angular separation 48 of about 30-55 degrees, about 40-45 degrees, or about 45 degrees from main inlet 41, but in the opposition direction of first angular separation 47. The three holes of draw inlet assembly thus form a roughly triangular formation. Side holes 42, 43 connect draw lumen 24 to exterior 11 of dual-lumen catheter shaft assembly 10. Side holes 42, 43 form secondary flow paths into draw lumen 24.

[0062] FIGS. 4A-4C show alternative arrangements of main inlet 41, first side hole 42, and second side hole 43, in which the closer of the side holes to main inlet 41 is different, or in which the distal/proximal positions of main inlet 41, on one hand, and first side hole 42 and second side hole 43, on the other, are switched.

[0063] Returning to FIGS. 1A, 1B, 2, and 3A-3G, return outlet assembly 50 includes main hole 51 and, optionally, extra fenestrations 52 (see FIGS. 7A-7B). Return outlet assembly 50 has, where extra fenestrations 52 are provided, longitudinal outlet spacing 54 between main hole 51 and extra fenestrations 52, and has return outlet assembly length 59. Return outlet assembly 50 is adjacent to distal tip 13 of dual-lumen catheter shaft assembly 10, while main hole 51 is at distal tip 13. Main hole 51 faces distally and is at the distal end of return lumen 26, thus connecting return lumen 26 to exterior 11 of dual-lumen catheter shaft assembly 10.

[0064] Dual-lumen catheter shaft assembly 10 connects to draw tubing 91 and return tubing 92 (and thence to apheresis machine 96) via Y-body 60 (or connector portion or divergent connector). Y-body 60 connects on its distal end to dual-lumen shaft assembly 10. Y-body 60 includes draw section 61 and return section 65. Draw section 61 includes Y-body draw lumen 62, Y-body draw outlet 63 (proximally), and Y-body draw inlet 64 (distally). Y-body draw lumen 62 fluidly connects Y-body draw inlet 64 (distally) and Y-body draw outlet 63 (proximally). Return section 65 includes Y-body return lumen 66, Y-body return outlet 67 (distally), and Y-body return inlet 68 (proximally). Y-body return lumen 66 fluidly connects Y-body return inlet 68 (proximally) and Y-body return outlet 67 (distally). Y-body 60 forms a divergent connector as it joins draw lumen 24 and return lumen 26, in shaft body 20, (having combined circular profile) into a single body for delivery/return to apheresis machine 96. In doing so, Y-body draw lumen 62 diverges from Y-body return lumen 66. Thus, there are two separate openings on the proximal side of the Y-body 60 for connecting tubing 91, 92 and connectors, e.g. for needle/connection to the machine, and one combined connection with openings for the two lumens in the shaft assembly. Y-body return lumen 66 is aligned in a straight line with return lumen 26 of shaft body 20 of dual-lumen catheter shaft 10 to permit rigid needle 70 to be aligned in both (see FIG. 1A & FIG. 5A with needle so aligned).

[0065] Turning to FIGS. 1A, 1B, 5A-5C, & 8, needle 70 includes hub 71, optionally flashback chamber 72, shaft 75, needle lumen 74, and beveled point 73. Needle lumen 74 runs down the interior of shaft 75, connecting flashback chamber to the exterior via an opening at beveled point 73. Hub 71 is used to safely handle the end of needle 70. Needle 70 may be 22G for for a 20G return lumen 26, where about a 130 mm needle may be long enough to extend from proximally of the proximal connector 93 to distally of distal tip 13.

[0066] Needle 70 is placed (before use) through return lumen 26 of dual-lumen catheter shaft 10 via Y-body return lumen 66 and connector 93 and tubing 92 for gaining access to interior 3 of vein 2. Beveled point 73 extends distally of shaft body 20 and distal tip 13 through main hole 51 of return lumen outlet assembly 50. Once needle 70 sufficiently enters vein 2 through wall 4 (in the direction against the direction of fluid flow 7), dual-lumen catheter shaft assembly 10 is advanced into vein 2, over needle 70 held stationary, until both draw inlet assembly 40 and return outlet assembly 50 are fully within vein 2. At this point, needle 70 has been partially retracted (by being stationary while assembly 10 advances). Once dual-lumen catheter shaft assembly 10 is in place, the rest of needle 70 is retracted and withdrawn safely. FIGS. 6A & 6B show the detail of two different embodiments of shaft body 20 inside vein 2, showing return flow 9 leaving return outlet assembly 50 and entering (joining) fluid flow 7 downstream of where draw flow 8 enters draw inlet assembly 40.

[0067] Needle 70 may be withdrawn directly or may be incorporated into shielding safety device 80 (see FIG. 8) to protect a user from the retracted needle. Shielding safety device 80 includes connector 81, casing 82, slot 85, and interior 83. A needle 70′ for using with shielding safety device 80 includes flashback chamber 72, shaft 75, as well as hub 71′ with, handle 87 and glider 88. Connector 81 is for engagement with connector 93 on return tubing 92, and permits all of shaft 75 to be extended and then be retracted therethrough. Handle 87 extends through slot 85 to permit a user to retract needle 70′, while glider 88 supports needle 70′ on interior 83 of casing 82.

[0068] Turning to FIG. 10, an embodiment of the invention permits the simultaneous draw and return fluids from a vein via a single using a dual-lumen catheter assembly. The method 200 include the following steps. Step 201 is inserting a needle within a Y-body return lumen and a return lumen of catheter shaft assembly, the Y-body return lumen and a return lumen of catheter shaft assembly being aligned in a straight line, and with a beveled end of the needle extending distally of the dual-lumen catheter shaft assembly through an outlet at the tip. Step 212 is inserting the beveled end and the catheter shaft assembly into the vein sufficiently. Step 213 is advancing, distally, a return lumen of the catheter shaft assembly, and the catheter shaft assembly, and a Y-body return lumen of a Y-body, and the Y-body, over the shaft of the needle. Step 215 is continuing that advance until both a draw inlet assembly and a return outlet assembly are fully within the vein. Step 216 is retracting the needle from the return lumen of the catheter shaft assembly, and the catheter shaft assembly, and the Y-body return lumen of the Y-body, and the Y-body. Step 218 is connecting an apheresis machine via tubing and connectors on the proximal side of the Y-body. Step 202 is drawing fluids from an exterior of the dual lumen catheter shaft assembly via a plurality of inlet holes of a draw inlet assembly connecting a draw lumen to the exterior, the drawing step occurring proximally of return step 204. Step 204 is returning fluids to the exterior of the catheter shaft assembly via a return outlet assembly connecting a return lumen to the exterior; the returning step occurring adjacent to a distal tip of the catheter assembly. Step 206 is maintaining recirculation of the fluids below 20%. Step 207 is maintaining recirculation of the fluids between about 10%-15%. Step 208 is carrying out an apheresis treatment on the fluids after drawing step 202 and before returning step 204. Step 210 is drawing fluids at a draw/return spacing of about 18-22 mm.

[0069] Turning to FIG. 11, an embodiment of the invention permits the simultaneous draw and return fluids from a vein via a single using a dual-lumen catheter assembly. The method 230 include the following steps. Step 251 is inserting a needle within a Y-body return lumen and a return lumen of catheter shaft assembly, the Y-body return lumen and a return lumen of catheter shaft assembly being aligned in a straight line, and with a beveled end of the needle extending distally of the dual-lumen catheter shaft assembly through an outlet at the tip. Step 252 is inserting the beveled end and the catheter shaft assembly into the vein sufficiently. Step 253 is advancing, distally, a return lumen of the catheter shaft assembly, and the catheter shaft assembly, and a Y-body return lumen of a Y-body, and the Y-body, over the shaft of the needle. Step 255 is continuing that advance until both a draw inlet assembly and a return outlet assembly are fully within the vein. Step 256 is retracting the needle from the return lumen of the catheter shaft assembly into a shielding safety device, and the catheter shaft assembly, and the Y-body return lumen of the Y-body, and the Y-body. Step 258 is connecting an apheresis machine via tubing and connectors on the proximal side of the Y-body. Step 232 is drawing fluids by a main draw flow path from the exterior of a dual-lumen catheter assembly into a draw lumen. Step 233 is providing one or more secondary flow paths from the exterior to the draw lumen. Step 235 is drawing fluids by one or more secondary flow paths from the exterior of a dual-lumen catheter assembly into a draw lumen. Step 234 is returning fluids to the exterior of the catheter assembly distally of the drawing step and adjacent to a distal tip of the catheter assembly. Step 236 is maintaining recirculation of the fluids below 20%. Step 237 is maintaining recirculation of the fluids between about 10%-15%. Step 238 is carrying out an apheresis treatment on the fluids after drawing step 232, providing step 233, and drawing step 235 and before returning step 234. Step 240 is drawing fluids at a draw/return spacing of about 18-22 mm. Step 242 is drawing fluids by a first secondary flow path separated by a first inlet spacing from said the main flow path. Step 243 is drawing fluids by a second secondary flow path separated by a second inlet spacing from said the main flow path, where the first and second inlet spacing are different. Step 245 is drawing fluids by a first secondary flow path separated angularly by about 30-55 degrees from the main flow path. Step 246 is drawing fluids by a second secondary flow path separated angularly by about 30-55 degrees in the opposite direction from the main flow path.