DELIVERY SYSTEM FOR BIFURCATION STENTS

1 . A stent delivery system comprising:

a catheter shaft having a stent deployment region near a distal end thereof;

a stent having a side portion on the stent deployment region of the shaft; and

a side branch sensor on the catheter shaft, wherein the sensor comprises an imaging component positioned on the shaft to view radially outwardly through the side branch portion of the stent.

2 . A stent delivery system as in claim 1 , wherein the stent deployment region comprises a balloon which carries the stent.

3 . A stent delivery system as in claim 1 , wherein the catheter shaft has only one guidewire lumen extending through the balloon which carries the stent.

4 . A stent delivery system as in claim 1 , wherein the width of the stent on the balloon does not exceed 1.5 mm.

5 . A method for deploying a prosthesis having a side branch portion in a side branch vessel in a main lumen, said method comprising:

providing a catheter carrying the prosthesis having the side portion;

advancing the catheter in the main lumen until the side portion is proximate the side branch;

imaging a wall of the main branch vessel with an imaging component carried on a shaft of the catheter, which imaging component provides a view through the side portion of the stent;

rotating and/or axially positioning the catheter while observing the relative position of the side portion and the side branch vessel using said imaging component;

deploying the prosthesis after observing the alignment of the side branch portion and the side branch vessel.

6 . A method as in claim 5 , wherein imaging component comprises an ultrasonic imaging transducer.

7 . A method as in claim 6 , wherein the ultrasonic imaging transducer is aligned with the side portion of the prosthesis.