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CA1092927A Expired / Lapsed CA ⏱️ 0.0 years remaining

Hemodialysis cannula for subclavian insertion

Assignee: ALLENTYNE Ltd
•
Filing: 1979-12-28
•
Granted: 1981-01-06
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Expires: 1999-12-28
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Abstract

Abstract ABSTRACT OF THE DISCLOSURE A double lumen cannula for hemodialysis and similar applications such as haemoperfusion comprises elongated flexible tubular members, disposed one within the other, for semi-permanent insertion into the sub-clavian vein of a patient, leaving semi-permanent access thereto for repeated hemodialysis treatments. The cannula is formed of an elongated flexible outer member, having a smooth exterior surface, and made up of an elongated main portion, a convergent, constricting portion and a narrower distal end portion which is tapered at the tip to fit over a Seldinger guide wire. There is also an inner member having a diameter substantially the same as that of the distal end portion. The inner member is insertable into the outer member to come into sealable engagement with the interior walls of the constricting portion, so as to form a continuous inner lumen with the distal end portion of the outer member, and is removable therefrom for removal of clot or replacement purposes. Both members are sufficiently flexible to permit curving thereof on a 12 cm radius without reduction in internal cross section thereof, i.e. without substantial kinking or buckling, so as to avoid constriction of fluid flows. Because the cannula provides two pathways for simultaneous extraction and return of blood there is no need to use a single needle machine to produce an alternating blood flow.

Inventors

  • 👤 P. Robert Uldall

Bibliographic Details

Application Number —
Jurisdiction CA
Data Source google_patents
Last Synchronized 2026-10-23 12:06
CPC Classifications
A; A61; A61M; A61M5/00; A61M5/14; A61M5/158; A61M5/1582; A61M25/00; A61M25/0021; A61M25/0023; A61M25/0026; A61M25/003; A61M2025/0031; A61M2025/0039

Claims Analysis

Total Claims: 10
Claim 1
Independent Claim 217 words
A double lumen cannula suitable for insertion into a large vein such as the subclavian vein of a patient for blood removal therefrom and blood return thereto, said cannula comprising an elongated flexible tubular outer member having a smooth outer surface and comprising a main elongated portion of first cross section, an integral convergent section and an integral distal end portion having a second cross section which is smaller than said first cross section; A plurality of blood flow apertures, spaced apart from one another in the side wall of said main portion adjacent the convergent section; at least one blood flow aperture in said distal end portion; an elongated flexible tubular inner member having a cross section smaller than said first cross section, the inner member being disposed within the outer member, the distal end of said inner member being disposed in substantially sealing end contact with the convergent section of the outer member so as to form, with the outer member, a pair of concentrically arranged discrete fluid flow lumens, the inner lumen constituted by said inner member and said distal end portion of the outer member, the outer lumen constituted by the main portion and the conver-gent section of the outer member; the inner member being releasable and withdrawable from within the outer member.
Claim 2
Dependent Claim 217 words
A double lumen cannula suitable for insertion into a large vein such as the subclavian vein of a patient for blood removal therefrom and blood return thereto, said cannula comprising an elongated flexible tubular outer member having a smooth outer surface and comprising a main elongated portion of first cross section, an integral convergent section and an integral distal end portion having a second cross section which is smaller than said first cross section; A plurality of blood flow apertures, spaced apart from one another in the side wall of said main portion adjacent the convergent section; at least one blood flow aperture in said distal end portion; an elongated flexible tubular inner member having a cross section smaller than said first cross section, the inner member being disposed within the outer member, the distal end of said inner member being disposed in substantially sealing end contact with the convergent section of the outer member so as to form, with the outer member, a pair of concentrically arranged discrete fluid flow lumens, the inner lumen constituted by said inner member and said distal end portion of the outer member, the outer lumen constituted by the main portion and the conver-gent section of the outer member; the inner member being releasable and withdrawable from within the outer member.
Claim 3
Dependent Claim 45 words
The cannula of claim 1,wherein said distal end portion of the outer member has a plurality of blood flow apertures, one said aperture being axially presented at the end thereof, the other said apertures being spaced apart from one another in the side wall thereof.
Claim 4
Dependent Claim 28 words
The cannula of claim 2 including a junction piece on the end of the distal end thereof, the inner member passing through one branch of said junction piece.
Claim 5
Dependent Claim 20 words
The cannula of claim 2 wherein both of said outer member and said inner member are of radio-opaque plastic material.
Claim 6
Dependent Claim 14 words
The cannula of claim 4 wherein said outer member is of radio-opaque tetrafluoroethylene polymer.
Claim 7
Dependent Claim 26 words
The cannula of claim 3 wherein the outer member has a length from about 18-22 cm, from its distal end portion extremity to its junction connection.
Claim 8
Dependent Claim 29 words
The cannula of claim 6 wherein the combined length of convergent section and the distal end portion of said outer member is from about 3 to about 4 cm.
Claim 9
Dependent Claim 28 words
The cannula of claim 7 wherein the blood flow aperture in the side wall of the main portion of the outer member are arranged in a spiral formation.
Claim 10
Dependent Claim 28 words
The cannula of claim 8 wherein the blood flow apertures in the side wall of distal end portion of the outer member are arranged in a spiral formation.

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