Vascular access configuration

Abstract

One embodiment is directed to a method for creating translumenal vascular access, comprising utilizing a dilator adaptor to assist with forming a substantially atraumatic geometric outer junction between a dilator member/introducer member assembly and a guidewire which may be somewhat undersized relative to a lumen formed through the dilator member, thereby creating a geometric fit gap which may be suboptimal from a tissue interfacing perspective. The dilator adaptor may be interposed between the guidewire and dilator member to assist in remedying this fit mismatch, and in generally providing a preferred outer instrument interface for insertion through a small defect in a vessel to gain access to a lumen defined through the vessel.

1 . A method for creating translumenal vascular access, comprising:
 a. placing a guidewire having a guidewire outer diameter across a portion of a vessel wall defining a vessel lumen so that a distal end of the guidewire extends into the vessel lumen and a proximal end of the guidewire extends proximally outside of the vessel lumen;   b. loading a proximal portion of a dilator adaptor into a distal end of a dilator lumen defined through a dilator member of a dilator-introducer assembly, to form an adapted-dilator-introducer assembly having at least a portion of the dilator adaptor inserted through at least a portion of the dilator lumen, and at least a portion of the dilator inserted through at least a portion of an introducer lumen defined through an introducer member of the dilator-introducer assembly;
 wherein the adapted-dilator-introducer assembly is configured such that a distal end of the dilator member extends distally beyond a distal end of the introducer member, and a distal end of the dilator adaptor extends distally beyond the distal end of the dilator member; and 
   c. advancing the adapted-dilator-introducer assembly into a position relative to the vessel wherein at least the distal end of the dilator adaptor is positioned within the vessel lumen by inserting at least a portion of the proximal end of the guidewire into the distal end of a lumen formed through the dilator adaptor.   
     
     
         2 . The method of  claim 1 , wherein placing the guidewire comprises advancing the guidewire through a portion of a needle that has been advanced across a portion of the vessel wall. 
     
     
         3 . The method of  claim 1 , wherein a maximum outer diameter of the guidewire is substantially smaller than a minimum inner diameter of the dilator member. 
     
     
         4 . The method of  claim 3 , wherein the maximum outer diameter of the guidewire is at least about 25% smaller than the minimum inner diameter of the dilator member. 
     
     
         5 . The method of  claim 3 , wherein the maximum outer diameter of the guidewire is about 0.018 inches. 
     
     
         6 . The method of  claim 5 , wherein the minimum inner diameter of the dilator member is between about 0.035 inches and about 0.040 inches. 
     
     
         7 . The method of  claim 3 , wherein the dilator adaptor has an outer diameter and inner diameter profile configured to substantially make up the difference in fit between the guidewire and dilator member. 
     
     
         8 . The method of  claim 7 , wherein loading the proximal portion of a dilator adaptor into the distal end of the dilator lumen defined through the dilator member comprises substantially eliminating annular fit gaps around a junction wherein the distal end of the dilator member meets the dilator adaptor. 
     
     
         9 . The method of  claim 6 , wherein the dilator adaptor has a minimum inner diameter of about 0.018 inches, and a maximum outer diameter of about 0.050 inches. 
     
     
         10 . The method of  claim 1 , wherein the introducer member distal end has a tapered geometry with an outer diameter minimum at its distal tip. 
     
     
         11 . The method of  claim 1 , wherein the dilator member distal end has a tapered geometry with an outer diameter minimum at its distal tip. 
     
     
         12 . The method of  claim 1 , wherein the distal end of the dilator adaptor has a tapered geometry with an outer diameter minimum at its distal tip. 
     
     
         13 . The method of  claim 1 , wherein at least a portion of the dilator adaptor has a proximally tapered geometry with an outer diameter minimum located adjacent its proximal tip. 
     
     
         14 . The method of  claim 13 , further comprising forming a friction fit between the proximally tapered geometry of the dilator adaptor and the dilator lumen of the dilator member when loading the dilator adaptor into the dilator lumen. 
     
     
         15 . The method of  claim 14 , wherein the proximally tapered geometry is selected such that one size of dilator adaptor can form a friction fit with a range of dilator lumen geometries. 
     
     
         16 . The method of  claim 1 , wherein the dilator adaptor, when viewed from distal tip to proximal tip, comprises a distal section with a substantially constant outer diameter for a distal section length, tapering up to a midsection with a substantially constant outer diameter for a midsection length, tapering down to a proximal section with a substantially constant outer diameter for a proximal section length, ending in the proximal tip. 
     
     
         17 . The method of  claim 16 , wherein the substantially constant outer diameter of the proximal section is greater than that of the distal section and less than that of the midsection. 
     
     
         18 . The method of  claim 17 , wherein each of the distal section, midsection, and proximal sections has a substantially homogeneous inner diameter defining an inner lumen through the dilator adaptor. 
     
     
         19 . The method of  claim 3 , wherein the maximum outer diameter of the guidewire is at least about 0.01 inches smaller than the minimum inner diameter of the dilator member. 
     
     
         20 . The method of  claim 1 , further comprising withdrawing the dilator member and dilator adaptor proximally out through a proximal end of the introducer member. 
     
     
         21 . The method of  claim 20 , further comprising inserting instrumentation through the introducer to conduct a cardiovascular procedure after the dilator member and dilator adaptor have been proximally withdrawn. 
     
     
         22 . The method of  claim 21 , further comprising proximally removing the introducer and guidewire, leaving behind a defect in the vessel wall that is self-sealing. 
     
     
         23 . The method of  claim 1 , wherein the dilator adaptor comprises a polymer selected from the group consisting of: polyethylene terepthalate, polyethylene, high density polyethylene, polypropylene, polytetrafluoroethylene, expanded polytetrafluoroethylene, poly (ethylene-co-vinyl acetate), poly(butyl methacrylate), and co-polymers thereof.