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AssigneeThe Curators of the University of Missouri
InventorsZbylut J. Twardowski, John C. Van Stone, W. Kirt Nichols
Estimating the term…
A catheter for hemodialysis comprises a flexible catheter tube defining a plurality of separate lumens. The catheter defines an arc angle of generally U-shape in its natural, unstressed configuration. Thus, the catheter may be implanted with a distal catheter portion residing in a vein of the patient, the distal catheter portion being of substantially the shape of the vein in its natural, unstressed condition. Also, a proximal catheter portion resides in a surgically created tunnel extending from the vein and through the skin of the patient, this section of the Catheter also being typically in its natural, unstressed condition. Thus blood may be removed from the vein through one lumen of the catheter, and blood may be returned to the vein through another lumen of the catheter, while the catheter is subject to long term indwelling in the body. Improved results are achieved because of the lack of mechanical stress in the shape of the catheter, which stress causes the catheter to press unduly against adjacent tissues.
The method of implanting a catheter in communication with a blood vessel of a patient, said catheter defining a pair of lumens to permit simultaneous withdrawal and replacement of blood to and from the patient, comprising the step of implanting said catheter in the patient with a proximal portion of the catheter extending through a surgically created tunnel, and a distal portion of said catheter extending through the venous system of said patient So that the distal tip of said catheter occupies the right atrium of the heart of the patient, said catheter, in its unstressed, as-manufactured configuration being of substantial U-shape and defining a central catheter arc and a pair of relatively straight catheter end portions respectively comprising said proximal and distal portions, said catheter penetrating the wall of the vein of said venous system at a position along said U-shaped arc, said catheter substantially occupying said unstressed, as-manufactured configuration in both said venous system and said surgical tunnel, said catheter having a proximal end which extends outwardly from the skin of said patient.
A catheter for hemodialysis which comprises a flexible catheter tube having a distal end and defining a plurality of separate lumens, said catheter defining a first arc angle portion in its natural, unstressed configuration which is substantially coplanar with a major portion of the catheter, said first arc angle portion being spaced from the catheter distal end, said catheter also defining, in its natural, unstressed condition, a second arc angle portion adjacent to said first arc angle portion and positioned between said first arc angle portion and said distal end, said second arc angle portion extending in a direction substantially perpendicular to the direction of said first arc angle portion, said catheter being adapted to be positioned in the femoral vein, said catheter being of a length to permit positioning of the distal catheter end in the inferior vena cava when the catheter is placed in the femoral vein, said first arc angle portion being of essentially 10.degree. to 50.degree. and extending essentially 50-200 mm, said second arc angle portion defining an arc of essentially 20.degree. to 50.degree. and extending essentially 20-50 mm, said catheter defining a shape, in its natural, unstressed condition, which is substantially of the shape of said femoral vein and inferior vena cava, whereby portions of said catheter do not press against vein walls.
The method of implanting an indwelling, multiple lumen, venous catheter which comprises:
Dependencies are inferred from the claim text.