Title:
METHOD OF INTRODUCING AN INTRAVENOUS CATHETER INTO THE VASCULAR SYSTEM
United States Patent 3598118


Abstract:
A needle comprising a tube, having a pointed leading end, a longitudinal hairline slot extending the length thereof, collar means spaced from the pointed leading end, and tube walls of sufficient flexibility to permit expansion of the needle upon insertion of a catheter therethrough when the catheter has an outside diameter which is larger than the inside diameter of the tube, is employed to introduce catheters into body cavities. In use, the needle is inserted into the cavity, the catheter is then passed through the needle into the cavity causing expansion of the needle, the needle is withdrawn from the body along the catheter and, by use of the collar to further expand the needle, removed longitudinally from the needle.



Inventors:
WARREN JOSEPH E
Application Number:
04/778914
Publication Date:
08/10/1971
Filing Date:
11/04/1968
Assignee:
JOSEPH E. WARREN
Primary Class:
Other Classes:
604/160, 606/108
International Classes:
A61M25/06; (IPC1-7): A61M25/06; A61m005/00
Field of Search:
128/214.4,221,343,345,348
View Patent Images:
US Patent References:
3359978Guide needle for flexible catheters1967-12-26Smith
3330278Hypodermic needle for a cannula placement unit1967-07-11Santomieri
2842133Surgical or medical vein dilating device1958-07-08Uhma
2566499Expansile surgical needle1951-09-04Richter
0673598N/A1901-05-07



Foreign References:
DK109789A1989-09-09
Primary Examiner:
Truluck, Dalton L.
Parent Case Data:


This application is a continuation-in-part of copending application Ser. No. 564,935 filed July 13, 1966, now abandoned.
Claims:
What I claim is

1. A method for introducing a catheter into a patient's body cavity with an expansion needle comprising a flexible tube having a circular cross section, a pointed leading end and a single longitudinal hairline slot through the tube wall and extending the entire length of said tube, the wall of said tube being sufficiently flexible to permit radial expansion of said needle on insertion of a catheter having an outside diameter which is greater than the normal inside diameter of said tube through said tube and collar means for withdrawing the needle from the patient along the catheter and for removing it longitudinally therefrom by further expansion of said needle, said method comprising passing said needle through body tissues and into a body cavity, passing a catheter having an outside diameter greater than the inside diameter of said tube through the bore of said tube and into said cavity, whereby the walls of said tube expand about said catheter, withdrawing said needle from the body of said patient along said catheter while leaving said catheter in place, and further expanding said needle and withdrawing it longitudinally from said catheter.

2. A method for introducing a catheter into the lumen of a blood vessel as defined in claim 1.

Description:
This invention is concerned with a needle useful in the introduction of catheters into body cavities, and to a method for its use.

More particularly, this invention relates to an expandable needle which is useful for introducing catheters into body cavities, and in a preferred form relates to an intravascular needle which eliminates the need for performing a surgical cutdown procedure and avoid the disadvantages of retained intravascular needle procedures.

The surgical cutdown procedure consists of making an incision through the skin and subcutaneous tissue until the desired blood vessel is reached. The blood vessel is isolated from its bed, ligatures are applied and the distal end of the vessel is tied. After the distal ligature is tied, the vessel is incised and an intravascular catheter is inserted into the lumen of the vessel through the incision, where the catheter is anchored.

A common alternative to the surgical cutdown procedure has been the implacement of a conventional intravenous needle for purposes of catheterization, infusion or transfusion. However, this alternative procedure may result in damage to the vessel by the relatively rigid and sharp needle, thereby resulting in inflammation, phlebitis, leakage and infiltration of solutions being administered, and the occurrence of pain, discomfort, tissue damage, sloughing and the loss of therapeutic effect.

The present expansion needle and catheter technique provides for the insertion of a catheter by simple needle puncture, followed by advancing the catheter within the needle, and allows for immediate removal of the needle, which if left in place could cause the complications referred to above.

With specific reference to intravascular catheterization procedures, the present invention provides for the simple, sterile insertion of the needle into a blood vessel, insertion of the catheter through the expandable bore of the needle into the blood vessel lumen and removal and discard of the needle in one, continuous, simple procedure which combines the advantages of catheter cannulation and needle infusion.

The sterility of the needle and intravascular portion of the catheter is maintained by disposable and easily removable plastic sterile field covers.

The device is readily adaptable for use with conventional infusion and transfusion sets.

Attempts to solve the problem of implanting a catheter in the lumen of a blood vessel without surgical cutdown or incision have heretofore failed to provide a satisfactory solution. For example, catheter introducers not employing the principles of this invention have had the shortcoming of requiring a much larger introducer than the catheter being implanted. Thus, a larger than necessary opening was required through the skin and subcutaneous tissue, with attendant damage to the blood vessel itself. Other problems of these prior art devices include an undesirable slippage of the catheter within an unexpandable, inflexible introducer, and leakage and damage to tissues and blood vessels due to a relatively large longitudinal opening in the introducer which tends to snag and fill up with skin and subcutaneous tissue. Also, some of the devices require pinching and extensive manipulation of the catheter within the introducer, with consequent damage thereto and discomfort to the patient.

Other devices have utilized a slotted sheath or other introducer which is longitudinally removable. Such devices, however, still require a separate needle attached to the catheter tube which is not slotted nor longitudinally removable and which, therefore, requires leaving the needle in place during transfusion or infusion unless the apparatus is taken apart to remove the needle, with all the complications that would result. Such instruments utilize an inordinate number of parts which might cause complications and which make their use more difficult and time consuming.

The prior art devices also have the distinct disadvantage of not being packaged in a sterile container and utilized as a single unit whereby the needle or introducer can be simply withdrawn and longitudinally removed and disposed of, leaving only the implanted catheter. The simply utilized packaged unit envisioned here has the attendant advantage of being sterile and ready for use, making a transfusion or infusion simpler to perform.

The present invention allows for continuous fluid transfusion or infusion after the catheter has been implanted while the needle is being withdrawn and removed. The pressure of the fluid from the flask through the infusion tubing through the catheter tube itself remains relatively constant at a preselected rate, during this operation, which assists in the prevention of clotting, leakage, and the other problems noted above.

The principle of flexibility and expandability in the needle of the present invention by means of a hairline slot in the needle allows the use of a needle that has approximately the same inside diameter as that of the catheter itself. This makes the introduction and implanting of the catheter a simpler, safer and more comfortable operation, as well as making the longitudinal removal of the needle possible. It also allows the greatest volume of fluid to pass through the catheter, consistent with the size of the opening required to be made through the skin, subcutaneous tissue and blood vessel wall.

An object of this invention is to provide for a simple method of catheterization, infusion or transfusion by means of a needle-catheter device which combines the advantages of catheter cannulation and conventional needle infusion.

A further object of this invention is to provide for a simple method of catheterization, infusion or transfusion by means of a needle-catheter device which allows for the placement of a catheter within the lumen of a blood vessel by means of a flexible, expandable intravascular needle, which may then be easily withdrawn, removed and discarded.

Still another object of this invention is to provide for a simple method of catheterization, infusion or transfusion by means of a needle-catheter device which allows for the placement of a catheter within the lumen of a blood vessel by means of a slotted flexible, expandable intravascular needle, which by reason of such slot, may be easily withdrawn, removed and discarded.

Further objects and advantages of this invention will appear from the following description.

FIG. 1 is a perspective view of the intravascular expansion needle and catheter connected to a typical adapter and fluid source, after the needle has been inserted and the catheter advanced within the needle.

FIG. 2 is a sectional view taken along line 2-2 of FIG. 1 and seen in the direction of the arrows.

FIG. 3 is a sectional view of the intravascular expansion needle taken along line 3-3 of FIG. 2 and seen in the direction of the arrows.

FIG. 4 is a perspective view showing the relation of the expansion needle to the catheter after the expansion needle has implanted the catheter in the blood vessel and as the expansion needle is being withdrawn in the direction of the arrow.

FIG. 5 is a sectional view of the expansion needle and the catheter tube as the expansion needle is being longitudinally removed from the catheter tube after the needle has been withdrawn axially along the catheter tube as shown in FIG. 4.

FIG. 6 is a perspective view showing the catheter tube implanted within the blood vessel after the expansion needle has been withdrawn, removed and discarded.

Referring to the figures, and particularly to FIG. 1, infusion flask 1 is shown connected to an adapter which is in turn connected to infusion tube 3 which is in turn connected to catheter 10. Catheter 10 is surrounded by expansion needle 4 which is made of metal and is slotted at 5. A flexible flange 6 is attached to the needle 4 for easy insertion, withdrawal, and removal of the needle. The needle 4 and catheter 10 have been inserted through the skin and subcutaneous tissue 7 into the lumen 8 of blood vessel 9.

The sharp intravascular needle 4 permits simple penetration of the blood vessel wall 9. As the catheter 10 is passed through the inserted needle 4 into the blood vessel lumen 8 the expansion needle slot 5 allows for gradual unobstructed and safe passage of the catheter 10 and when the walls of the needle tube are of substantially uniform thickness the inside surface of the tube conforms to and remains in contact with the outside surface of the catheter. The tip 11 of the catheter 10 can then be easily held in place with the fingers by simply pressing down on the skin area 7 overlying the catheterized vessel 9. The needle 4 can then be withdrawn over the infusion tubing 3 and the catheter 10 anchored in the vessel 9 by conventional taping of the externally remaining portion of the catheter 10 to the skin surface. To remove the needle 4 from the tubing 3, the needle flange 6 is simply spread apart and the needle 4 lifted away from the tubing 3 through the expanded needle slot 5 and the needle 4 discarded.

The intravascular catheter is designed to decrease the possibility of leakage, vessel puncture and tissue damage, and to minimize the possible formation of blood clots or thrombi. The tapered, shaped, rounded edge 11 is relatively atraumatic. The progressive step-wise decrease in diameter from infusion flask 1 to infusion tubing 3 to the intravascular catheter 10 allows for a proportional increase in fluid pressure and velocity of the infused solution at the catheter tip 11. This provides further insurance against obstruction to effective catheter flow and against formation of blood clots and thrombi. Compounding of the plastic material with silicone when so desired provides additional protection against clot formation.

While the foregoing discussion has been specifically directed toward intravascular procedures, it is clear that the present invention is useful in connection with any procedure in which catheterization of a body cavity by penetration of body tissues is required. For example, the needle and method of the present invention are useful for catheterization of the thoracic cavity, the abdominal cavity, the cardiac cavity and the like, as well as the venous and arterial cavities comprising the vascular cavity.