Blood treatment catheter and method

Abstract

A blood infusion and aspiration catheter has an annular lumen surrounding a central lumen. The annular lumen, whether used for infusion or aspiration, has a set of ports which are aligned along a circular circumference so that they intersect a common plane. That common plane is substantially perpendicular to the axis of the annular lumen. This structural arrangement avoids the compromise of heparin lock that occurs when the exit or entrance ports at the distal end of the annular lumen are circumferentially staggered. These ports in the annular lumen face radially outward to assure that port edges do not snag on tissue when the catheter is inserted.

1 . A catheter comprising: 
 an aspiration lumen and an infusion lumen,    a first one of said lumens having a distal annular lumen segment circumferentially deployed around the second one of said lumens, said annular lumen segment having an axis and a sidewall,    a distal port arrangement in said side wall comprising one or more individual ports,    each port of said port arrangement intersecting a common plane, said common plane being substantially perpendicular to said axis of said annular lumen segment,    each of said ports has an axis substantially perpendicular to said axis of said annular lumen,    said port arrangement constituting the sole ports of said annular segment.    
   
   
       2 . The catheter of  claim 1  wherein: said ports are at the distal end of said annular lumen segment.  
   
   
       3 . The catheter of  claim 1  wherein: said infusion lumen is said annular lumen.  
   
   
       4 . The catheter of  claim 2  wherein: said infusion lumen is said annular lumen.  
   
   
       5 . The catheter of  claim 1  wherein: each of said lumens has an outer wall and wherein said distal port arrangement is in part defined by segments of said annular lumen outer wall segments extending between said ports and merging into said outer wall of said second one of said lumens.  
   
   
       6 . The catheter of  claim 5  wherein: said ports are at the distal end of said annular lumen segment.  
   
   
       7 . The catheter of  claim 5  wherein: said infusion lumen is said annular lumen.  
   
   
       8 . The catheter of  claim 6  wherein: said infusion lumen is said annular lumen.  
   
   
       9 . The catheter of  claim 1  wherein: wherein said distal port arrangement comprises a set of triangular ports nested against each other.