Method and apparatus for catheterization access

An access tube assembly comprising:

• an elongate dilation member including a radially expandable tubular body having a proximal end, a distal end, an axial lumen, and a penetration member at the distal end;
• an elastic access tube having a proximal end, distal end, and a central lumen extending from the proximal end to the distal end, wherein the tube has an intrinsic length and intrinsic outer diameter when not under axial tension or radial compression;
• and
• a stylet receivable within the central lumen and engagable against the distal end of the elastic access tube, wherein a tapered distal end is formed on the elastic access tube when under axial tension from the stylet, whereby the tapered distal end facilitates introduction of the access tube and stylet through the axial lumen of the elongate dilation member.

A method for introducing and anchoring an access tube in a tissue penetration, said method comprising:

• penetrating an elongate dilation member through tissue to a target location;
• introducing the access tube through a lumen of the elongate dilation member while the access tube is under sufficient axial tension so that the outer diameter of the tube is at least 10% less than the intrinsic diameter when the tube is not under stress;
• removing the elongate dilation member to leave the access tube in the tissue penetration;
• and
• releasing the axial tension so that the diameter of the tube expands so as to dilate and seal radially against peripheral tissue along the penetration.

An access tube assembly comprising:

• an elastic access tube having a proximal end, a distal end, and a radially sealed central lumen extending from the proximal end to the distal end, wherein the tube has an intrinsic length and intrinsic outer diameter when not restrained under an axial tension or a radial compression;
• a stylet receivable within the central lumen and coupled to the distal end of the elastic access tube;
• and
• a removable sheath covering at least a distal portion of the elastic tube and having an inner diameter which is less than the intrinsic outer diameter of the elastic tube;
• wherein the elastic access tube is releasably restrained so as to have a reduced outer diameter.