Guided ablation with end-fire fiber
A method and apparatus for treating a body tissue in situ (e.g., an atrial tissue of a heart to treat atrial fibrillation) include a lesion formation tool is positioned against the heart surface. The apparatus includes a guide member having a tissue-opposing surface for placement against a heart surface. The guide member also has interior surfaces and a longitudinal axis. A guide carriage is sized to be received with the guide member and moveable therein along the longitudinal axis. An optical fiber is positioned within the guide carriage with the carriage retaining the fiber. The carriage receives the fiber with an axis substantially parallel to the longitudinal axis and bends the fiber to a distal tip with an axis of said fiber at said distal tip at least 45 degrees to the longitudinal axis and aligned for discharge of laser energy through the tissue opposing surface.
1. An apparatus for forming a lesion in tissue along a desired ablation path, said apparatus comprising:
a guide member having a tissue-opposing surface for placement against a heart surface, said guide member having interior surfaces and a longitudinal axis;
said guide member including a track extending at least partially along a length of said guide member;
and said apparatus further comprises a carriage slidably received with said track, said ablation member secured to said carriage for guiding movement therewith
said guide carriage slidably received within said track and moveable therein along said longitudinal axis,
an optical fiber within said guide carriage and secured thereto for movement therewith;
said carriage retaining said fiber and receiving said fiber with an entrance axis to said longitudinal axis at an entrance angle substantially less than 45 degrees and bending said fiber to a distal tip with a discharge axis of said fiber at said distal tip to said longitudinal axis at a discharge angle of at least 45 degrees and aligned for discharge of laser energy, from a laser source, through said tissue opposing surface and with an alignment of said distal tip and said carriage remaining constant throughout movement of said carriage.
2. An apparatus according to claim 1 wherein said carriage includes surfaces opposing said fiber to define a fluid pathway for receiving a fluid to wash over said fiber at said distal tip.
3. An apparatus according to claim 1 wherein said guide carriage has exterior surfaces cooperating with said interior surfaces of said guide member to permit movement of said carriage relative to said guide member to be substantially restricted to movement along said longitudinal axis.
4. An apparatus according to claim 1 wherein said carriage retains said fiber in alignment with a slot formed through said tissue-opposing surface.
5. An apparatus according to claim 1 wherein said guide member is flexible about said longitudinal axis in at least one direction.
6. An apparatus according to claim 1 wherein said entrance angle is approximately zero degrees.
7. An apparatus according to claim 1 wherein said discharge angle is greater than 60 degrees.