Abstract: A dual lumen catheter is disclosed for providing extracorporeal treatment such as hemodialysis, which is percutaneously inserted for either short-term or long-term vascular access. The catheter includes a main body having proximal and distal segments connected to a pair of clamping limbs via a manifold. The distal segment includes two tubular members laterally attached to each other, one of which is thinner than the other and collapsible for inserting the catheter through a much smaller diameter peel-away sheath. Contrary to existing practices, the lengths of the arterial and venous tubular members are reversed such as to provide a longer negative pressure intake lumen. A hydrophilic slip coating covers the distal segment to further ease the insertion of the distal segment into the peel-away sheath. The cross-sectional area of the proximal segment is generally elliptical shaped for providing a leak proof fit through the vascular access site.

Abstract: 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.