Dual lumen sheath for arterial access

Abstract

A sheath assembly for the insertion of a percutaneous pump includes a tubular sheath body dimensioned for insertion into a blood vessel through a vessel aperture. The tubular sheath body includes a wall having a proximal end portion, a distal end portion, a longitudinal axis, an outer surface, an inner surface defining a first lumen substantially parallel to the longitudinal axis, and a second lumen disposed within the wall between the inner surface and the outer surface and extending from the proximal end portion to the distal end portion. The first lumen is dimensioned to allow passage of a portion of the percutaneous pump, and the second lumen is dimensioned for passage of a guidewire. A stylet is removably positioned to substantially occlude the second lumen. The stylet has a proximal end releasably secured to the sheath assembly.

1 .- 15 . (canceled) 
     
     
         16 . A method for maintaining guidewire access comprising:
 inserting a sheath into a blood vessel through a percutaneous insertion path and along a portion of a percutaneous pump, wherein the sheath has a first lumen and a second lumen;   maintaining the sheath in the blood vessel for more than 6 hours while preventing blood clot formation from occluding the second lumen; and   inserting a guidewire through the second lumen into the percutaneous insertion path after the more than 6 hours.   
     
     
         17 . The method of  claim 16 , wherein the preventing blood clot formation from occluding the second lumen comprises inserting a stylet into the second lumen for more than 6 hours, and removing the stylet before inserting the guidewire. 
     
     
         18 . The method of  claim 16 , wherein the preventing blood clot formation from occluding the second lumen comprises flushing the second lumen with purge fluid. 
     
     
         19 . The method of  claim 16 , further comprising removing the sheath while maintaining the guidewire in the percutaneous insertion path. 
     
     
         20 . The method of  claim 19 , further comprising inserting a percutaneous tool over the guidewire into the percutaneous insertion path after the sheath is removed. 
     
     
         21 . The method of  claim 19 , wherein the second lumen having a proximal inlet and a distal outlet, and wherein the method further comprising:
 coupling a sensor to the proximal inlet of the second lumen; and   transducing arterial pressure at the distal outlet of the second lumen using the sensor.   
     
     
         22 . The method of  claim 21 , wherein the method further comprises rotating the sheath relative to a support structure when an arterial pressure measurement indicates that the distal outlet of the second lumen is occluded by an arterial wall. 
     
     
         23 . The method of  claim 22 , further comprising determining a depth of insertion from the arterial pressure measurement. 
     
     
         24 . The method of  claim 23 , wherein the depth of insertion is determined based on markings disposed on an outer surface of the sheath.