A laser energy delivery device and method are provided for irradiating a body
tissue
with relatively long wavelength laser energy in the presence of an aqueous liquid
without significant absorption of the laser energy by the liquid. The device includes
an elongate hollow sheath that is open at its distal end and closed at its proximal
end, a laser energy conduit such as an optical fiber or hollow waveguide, within
the sheath, the distal end of the conduit being disposed near the open distal end
of the sheath, and the proximal end of the conduit being adapted for connection
to a source of long wavelength laser energy. The sheath also includes an inlet
port, spaced from the proximal end of the sheath, and adapted to receive and deliver
a biologically compatible gas through the sheath to a body tissue site in contact
with the open distal end of the sheath.