Multi-stage balloon catheter
A multistage balloon catheter that uses a single lumen to inflate a balloon in stages is disclosed. A fluid port provides fluid communication from an inflation lumen in the balloon catheter to the inner volume of a distal balloon. The distal balloon expands as fluid in delivered to the inner volume of the distal balloon. Once inflated, the pressure continues to rise until a threshold pressure is exceeded. A pressure sensitive inflation valve provides fluid communication into an inner volume of a second balloon disposed at least partially proximal to the distal balloon. The pressure sensitive valve allows fluid communication into the second balloon once the threshold pressure is reached in the first balloon thereby inflating the second balloon.
1. A balloon catheter assembly comprising: a catheter having a proximal end and a distal end;
a first balloon disposed at a distal portion of the catheter, the first balloon having a first balloon wall and a first interior volume;
a second balloon disposed at least partially proximal to the first balloon, the second balloon having a second balloon wall and a second interior volume;
a pressure actuated inflation valve operably coupled to the second balloon, the pressure actuated inflation valve providing fluid communication between an inflation lumen and the second interior volume through the inflation valve when a threshold fluid pressure is exceeded in the first balloon, where the pressure actuated inflation valve inhibits fluid flow through the valve below the threshold fluid pressure at which the valve permits fluid flow through the valve; and
the inflation lumen extending from the proximal end of the catheter to the distal end of the catheter, the inflation lumen being in fluid communication with the first interior volume and the second interior volume when the threshold fluid pressure is exceeded in the first balloon so that the inflation lumen is used to inflate both the first and the second balloons;
wherein the second balloon is inflated after the first balloon is inflated and the second balloon wall is in contact with the first balloon wall when the first and second balloons are inflated; and
wherein the pressure actuated inflation valve is disposed between the catheter and the second balloon and passes from the lumen into the second interior space.
2. The balloon catheter assembly of claim 1 wherein the first balloon is disposed within the second interior volume.
3. The balloon catheter assembly of claim 1 , wherein the pressure actuated inflation valve comprises a rupture disk.
4. The balloon catheter assembly of claim 1 wherein the catheter has only one inflation lumen.
5. The balloon catheter assembly of claim 1 wherein the first balloon is disposed within the second balloon, the pressure actuated inflation valve is covered by the second balloon when uninflated, and the threshold fluid pressure is a pressure sufficient to inflate the first balloon to a point uncovering the pressure actuated inflation valve.