Sequentially inflatable balloons for delivery of treatment agents

Abstract

An apparatus including a cannula having a dimension suitable for insertion into a blood vessel and an expandable body coupled thereto, the expandable body comprising a first expandable member and a second expandable member to isolate a length of the vessel upon expansion within the blood vessel. The expandable body having an intermediate expandable member along a working length between the first expandable member and the second expandable. A method including introducing a cannula and an expandable body coupled thereto into a blood vessel at a point coextensive with a treatment site and expanding a first expandable member and a second expandable member of the expandable body to isolate a length of the vessel adjacent the treatment site. The method further including delivering a treatment agent to a vessel region between the first expandable member and the second expandable member while inflating and deflating an intermediate expandable member.

What is claimed is: 
     
         1 . A method comprising:
 introducing a cannula having a dimension suitable for insertion into a blood vessel and a first expandable body coupled thereto into a blood vessel at a point coextensive with a treatment site;   expanding a first expandable member and a second expandable member of the first expandable body to isolate a length of the vessel adjacent the treatment site;   delivering a treatment agent to a vessel region between the first expandable member and the second expandable member; and   expanding an intermediate expandable member positioned along a working length of the first expandable body, between the first expandable member and the second expandable member, using a second expandable body positioned within the first expandable body, and wherein the second expandable body is movable along the working length of the first expandable body.   
     
     
         2 . The method of  claim 1 , wherein the first expandable member, the second expandable and the intermediate expandable member are expanded simultaneously prior to delivering the treatment agent to minimize blood volume within the vessel region between the first expandable member and the second expandable member. 
     
     
         3 . The method of  claim 1 , wherein the working length comprises a plurality of intermediate expandable members and wherein the plurality of intermediate expandable members are sequentially expanded to increase a pressure within a vessel lumen along different portions of the vessel length between the first expandable member and the second expandable member. 
     
     
         4 . The method of  claim 3 , wherein the intermediate expandable members are selectively expanded and contracted according to conditions that generate a peristaltic motion along the working length of the expandable body. 
     
     
         5 . The method of  claim 1 , wherein delivering comprises releasing a treatment agent through pores within a wall of the intermediate expandable member. 
     
     
         6 . The method of  claim 1 , wherein delivering comprises releasing a treatment agent through a delivery cannula terminating within the vessel region between the first expandable member and the second expandable member. 
     
     
         7 . The method of  claim 1  wherein the intermediate expandable member comprises a plurality of intermediate expandable members, and the second expandable body comprises a first balloon and a second balloon attached to opposite ends of a secondary cannula, and the secondary cannula comprises a length dimension similar to a length of one of the plurality of intermediate expandable members such that the first balloon and the second balloon are disposed within, and facilitate expansion of, every other one of the plurality of intermediate expansion members. 
     
     
         8 . A method comprising:
 introducing a cannula having a dimension suitable for insertion into a blood vessel and an expandable body coupled thereto into a blood vessel at a point coextensive with a treatment site;   expanding a first expandable member and a second expandable member of the expandable body to isolate a length of the vessel adjacent the treatment site;   expanding an intermediate expandable member positioned along a working length of the expandable body, between the first expandable member and the second expandable member, to reduce a blood volume within the isolated length of the blood vessel;   contracting the intermediate expandable member once the blood volume is reduced;   delivering a treatment agent to the isolated length of the blood vessel having the reduced blood volume; and   expanding the intermediate expandable member after delivering of the treatment agent so as to drive the treatment agent into the treatment site.   
     
     
         9 . The method of  claim 8  wherein the expandable body is a first expandable body, and expanding the intermediate expandable member comprises expanding a second expandable body movably disposed within the first expandable body. 
     
     
         10 . The method of  claim 9  wherein the second expandable body comprises a first balloon and a second balloon fixedly attached at opposite ends of a secondary cannula. 
     
     
         11 . The method of  claim 8 , wherein the expandable body comprises an elongated balloon, the first expandable member and the second expandable member are at opposite ends of the elongated balloon and the intermediate expandable member is a cuff positioned around a portion of the working length. 
     
     
         12 . The method of  claim 11 , wherein the cuff is moved along the expandable body according to conditions that generate a peristaltic motion along the working length of the expandable body. 
     
     
         13 . The method of  claim 11 , wherein delivering comprises releasing a treatment agent through a delivery cannula coupled to the cuff.