Methods and apparatus for aspiration and priming of inflatable structures in catheters

Abstract

An aspiration baffle comprises an outer tube and an inner core wire. Microholes are provided in the outer tubular member to permit passage of gas but inhibit the passage of liquids. The aspiration baffle is used in a catheter having a balloon or other inflatable structure to assist in priming of the structure. After evacuating the inflatable structure by applying a vacuum, the aspiration baffle can collect and trap residual gas which remains during the priming of the inflatable structure.

1 . A method for priming an inflatable chamber on a catheter with liquid, said method comprising: 
 drawing a vacuum in the chamber through the inflation lumen to remove gas, wherein a residual amount of gas is left; and    filling the chamber with liquid;    wherein an aspiration baffle is disposed in the catheter body said baffle defining a sealed interior volume open to an interior of the inflatable chamber through a plurality of microholes only;    wherein the interior volume of the aspiration baffle is evacuated through the microholes as the vacuum is drawn in the interior of the inflatable chamber through the inflation lumen so that the residual amount of gas may pass from the inflatable chamber into the interior volume of said aspiration tube.    
     
     
         2 . A method as in  claim 1 , wherein the vacuum is drawn to a pressure of 15 mmHg or lower.  
     
     
         3 . A method as in  claim 2 , wherein the chamber is filled with liquid at a pressure of at least one atmosphere.  
     
     
         4 . A method as in  claim 3  wherein the chamber is filled with liquid at a pressure of at least two atmospheres.  
     
     
         5 . A method as in  claim 1  wherein the aspiration baffle further comprises a core wire disposed coaxially within the interior volume of the tubular member, wherein an annular gas flow path is formed between an interior wall of the tubular member and an exterior surface of the core wire.  
     
     
         6 . A method as in  claim 5 , wherein the tubular member has a length in the range from 10 cm to 200 cm and an outer diameter in the range from 0.1 mm to 1 mm, and wherein the microholes have a maximum width in the range from 0.001 mm to 0.1 mm.  
     
     
         7 . A method as in  claim 6 , wherein the microholes are disposed over only a distal length of the tubular member in the range from 1 cm to 20 cm.  
     
     
         8 . A method as in  claim 7 , wherein the core wire extends from the distal end of the tubular member over a distance in the range from 1 cm to 100 cm.