Apparatus and method for effecting percutaneous catheterization of a blood vessel using a small gauge introducer needle

• US 4,650,472 A
• Filed: 08/30/1985
• Issued: 03/17/1987
• Est. Priority Date: 08/30/1985
• Status: Expired due to Term

• Current Assignee: Cook Incorporated (Cook Group Incorporated)
• Original Assignee: Cook Incorporated (Cook Group Incorporated)
• Inventors: Bates, Brian L.
• Primary Examiner(s): Pellegrino, Stephen C.
• Application Number:
  US06/771,025
• Time in Patent Office: 564 Days
• Field of Search: 604/158, 604/161, 604/164, 604/170, 604/264, 604/280, 604/283, 128/656, 128/658
• US Class Current: 604/158
• CPC Class Codes: A61M 2025/09175 having specific characteristics at the distal tip
• CPC Class Codes: A61M 25/09 Guide wires

Abstract

A apparatus and method for percutaneous catheterization of a blood vessel permitting use of a small gauge needle is shown. A 22 gauge needle is used for making the initial entry into the blood vessel. A wire guide is then introduced into the blood vessel through the introducer needle, the needle then being withdrawn. A catheter and an inner cannula are passed in unison over the wire guide, through the skin and into the blood vessel. The cannula is provided with a tapered tip which extends through the distal opening of the catheter, thereby providing a diametrical transition between the small wire guide and the relatively larger catheter, resulting in a minimum of trauma during insertion. Once the catheter is in place, the inner cannula and wire guide are withdrawn, leaving the catheter in place with a relatively large distal opening, thereby promoting good fluid flow characteristics of the catheter.

Claims

1. A catheterization set for percutaneous catheterization of a blood vessel, comprising:

a hollow thin wall introducer needle having a lumen therethrough, said introducer needle being about 22 gauge and having an outer diameter of about 0.028 inches;

a wire guide sized to be received through the lumen of said introducer needle;

a catheter smaller than about French size 9 having proximal and distal open ends and a lumen therethrough;

a cannula having proximal and distal open ends and a lumen therethrough, said cannula sized to be received within the lumen of said catheter, the lumen of said cannula sized to receive said wire guide therethrough, the distal opening being just large enough to receive said wire guide freely therethrough, said cannula having a tapered distal portion having an outer diameter decreasing toward the distal end and sized to extend through the distal opening of said catheter to provide a smooth diametrical transition between the distal end of the catheter and the distal opening of said cannula; and

means connected to the proximal ends of said catheter and said cannula for temporarily fixing the longitudinal disposition of each with respect to the other such that said catheter and cannula are a unitary structure with a smooth tapered distal end, said means for fixing including a first connector fixed to the proximal end of said cannula, the first connector having an opening therethrough aligned with and communicating with the lumen of said cannula, and a second connector fixed to the proximal end of said catheter tube, the second connector having an opening therethrough aligned with and communicating with the lumen of said catheter tube, the second connector being cooperatively connectable to the first connector to temporarily maintain the catheter tube and the inner cannula in fixed longitudinal relationship with respect to each other.

2. The catheterization set of claim 1, wherein said wire guide has a solid mandrel and a flexible tip, the flexible tip including a helically wound wire coil.

3. The catheter apparatus of claim 2, wherein said wire guide has a diameter of about 0.018 inches.

4. The catheterization set of claim 1, wherein said introducer needle has an outer diameter less than about 0.049 inches, said wire guide has a diameter less than about 0.035 inches, and said catheter tube is sized in the range of about French size 3 to about French size 9.

5. A method of percutaneous catheterization of a blood vessel, comprising the steps of:

(a) providing a thin wall hollow percutaneous introducer needle having an outer diameter less than about 0.049 inches;

(b) providing a wire guide having a diameter less than about 0.035 inches and such that said wire guide is capable of passing through the bore of said introducer needle;

(c) providing an inner cannula having an open proximal end and an open distal end and a lumen therethrough communicating the distal end with the proximal end, said lumen having a diameter capable of receiving said wire guide therethrough, the distal opening of said inner cannula having a diameter slightly larger than said wire guide, said inner cannula having a smoothly taperd outer diameter at the distal end providing a decreasing diametrical transition to the distal end of said inner cannula, said inner cannula having a first connector fixed to the proximal end of said inner cannula, the first connector having an opening therethrough aligned with and communicating with the lumen of said cannula; and

(d) providing a catheter tube sized in the range of about French size 3 to about French size 9, and having an open proximal end and an open distal end and a lumen therethrough communicating the proximal end with the distal end, said lumen having a diameter capable of receiving said inner cannula therethrough, the distal opening of said catheter tube having a diameter slightly larger than said inner cannula, said catheter tube having a second connector fixed to the proximal end of said catheter tube, the second connector having an opening therethrough aligned with and communicating with the lumen of said catheter tube, the second connector being cooperatively connectable to the first connector to temporarily maintain the catheter tube and the inner cannula in fixed longitudinal relationship with respect to each other;

(e) introducing said introducer needle into said blood vessel percutaneously;

(f) while maintaining said introducer needle in place within said blood vessel, guiding said wire guide through said needle and into said blood vessel;

(g) while maintaining said wire guide in place within said blood vessel, withdrawing said introducer needle;

(h) disposing said inner cannula within the lumen of said catheter tube with the tapered distal end of the inner cannula extending beyond the distal end of the catheter tube to provide a diametrical transition from the distal end of said catheter tube to the distal end of said inner cannula, and maintaining said inner cannula and said catheter tube in such relative disposition by connecting the second connector to the first connector;

(i) passing said inner cannula and said catheter tube in unison over said wire guide, and introducing said inner cannula/catheter tube into said blood vessel;

(j) while maintaining said inner cannula/catheter tube within said blood vessel, withdrawing said wire guide; and

(k) while maintaining said catheter tube within said blood vessel, disconnecting the second connector from the first connector and withdrawing said inner cannula.