Vascular access configuration

A system for creating translumenal vascular access, comprising:

• a. a dilator-introducer assembly comprising a dilator member having proximal and distal ends and defining a dilator lumen therethrough, and an introducer member having proximal and distal ends and defining an introducer lumen therethrough, wherein the introducer lumen is defined by an inner diameter profile sized to accommodate insertion of one or more portions of the dilator member;
• b. a guidewire having an outer shape defined by a guidewire outer diameter profile;
• c. a dilator adaptor having proximal and distal ends and defining a dilator adaptor lumen therethrough, wherein the dilator adaptor lumen is defined by an inner diameter profile sized to accommodate insertion of one or more portions of the guidewire, and wherein the dilator adaptor is further defined by an outer diameter profile sized to accommodate at least partial insertion of the proximal end of the dilator adaptor into the dilator member lumen;
• wherein the guidewire may be advanced at least in part through the dilator adaptor lumen, the dilator adaptor may be advanced at least in part through the dilator member lumen, and the dilator member may be advanced at least in part through the introducer lumen to form an instrument assembly capable of forming substantially atraumatic outer shape profile configuration defined by longitudinally sequential increases in overall outer diameter from exposed distal ends of the guidewire, dilator adaptor, dilator member, and introducer.