INDWELLING ARTERIAL CANNULA ASSEMBLY

• US 3,565,074 A
• Filed: 04/24/1969
• Issued: 02/23/1971
• Est. Priority Date: 04/24/1969
• Status: Expired due to Term

• Current Assignee: Philip R. Foti
• Original Assignee: Philip R. Foti
• Inventors: Foti, Philip R.
• Application Number:
  US04/818,979
• Time in Patent Office: 670 Days
• US Class Current: 604/164.11
• CPC Class Codes: A61M 25/0606 "Over-the-needle" catheter assemblies, e.g. I.V. catheters

Abstract

An indwelling arterial cannula assembly includes a plastic catheter coaxially removably mounted on a blunt tipped cannula having a pointed stylet removably located in the bore thereof and extended beyond the blunt tip of the cannula; and a method is provided for positioning a portion of the plastic catheter of the assembly into an artery. The method includes the steps of projecting the assembly into the artery by piercing both the inner and outer walls of the artery with the point of the stylet and extending a portion of the assembly through the openings in both of the walls. Then the stylet is removed from the assembly and the remainder of the assembly is retracted until its forward tip reenters the artery and fluid from the artery flows through the cannula. The remainder of the assembly is then advanced into the lumen of the vessel to the desired position with the blunt tip of the cannula alleviating the danger of repuncture of the inner wall of the artery. Finally, the plastic catheter is slid forward while the cannula is removed therefrom which thereby locates a portion of the catheter in the desired position in the artery.

Claims

1. An indwelling arterial cannula assembly comprising:

a rigid cannula having a blunted forward tip, a hub connected to its rear end and a passage therethrough;

a plastic catheter having a passage therethrough, a hub connected to its rear end and being coaxially removably mounted on said cannula said catheter being shorter in length than said cannula; and

a stylet having a pointed forward end, a hub attached to its rear end and being removably positioned within the passage of said cannula with its forward end portion extending beyond the blunted tip of said cannula thereby facilitating the positioning of a portion of said assembly into an artery and the subsequent removal of said cannula and stylet from said catheter to leave a portion of said plastic catheter in the desired position within said artery.

2. The invention in accordance with claim 1 wherein the forward portion of said catheter tapers inwardly toward the forward end thereof and terminates to the rear of the blunt tip of said cannula to facilitate entrance of said assembly into said artery.

3. The invention in accordance with claim 1 wherein said cannula is composed of a metallic material.

4. The invention in accordance with claim 1 wherein said pointed stylet is composed of a metallic material.

5. The invention in accordance with claim 1 wherein said catheter is composed of polytetrafluoroethylene.

6. The invention in accordance with claim 1 wherein said cannula is rounded at its blunted tip end.

7. The invention is accordance with claim 1 wherein said printed stylet extends 4 mm. beyond the blunted tip of said cannula.

8. A method of positioning into an artery a portion of a plastic catheter of an indwelling arterial cannula assembly including a plastic catheter coaxially removably mounted on a blunt tipped, rigid cannula having a pointed stylet removably located in the bore thereof and extending beyond the blunt tip of the cannula said catheter being shorter in length than said cannula comprising;

projecting said assembly into the artery by piercing both the outer and inner walls of the artery with the point of said stylet and extending a portion of said assembly through the openings in the walls of said artery;

removing the stylet from said assembly;

retracting the remainder of said assembly until the forward tip thereof reenters the artery and fluid from said artery flows through said cannula;

advancing the remainder of said assembly into the lumen of the artery to the desired position with the blunt tip of said cannula alleviating the danger of repuncture of the inner wall of the artery; and

sliding the plastic catheter forward while removing the cannula therefrom thereby locating a portion of the catheter in the desired position in the artery.

9. The invention in accordance with claim 8 wherein after said cannula is removed from said catheter a plastic obturator is placed into the lumen of the catheter to alleviate the danger of clotting between the taking of samples of fluid from the artery.

10. The invention in accordance with claim 8 after said cannula is removed from said catheter a syringe containing an anticoagulant substance may be attached to the rear end of the catheter to alleviate the danger of clotting between the taking of samples of fluid from the artery.