Venting surgical cannula for providing gases to a patient

A surgical cannula for providing insufflation gases to a surgical cavity and for venting gases from the surgical cavity, the surgical cannula comprising:

• a cannula upper housing comprising:
• a gas entry port;
• and
• an opening for receiving a medical instrument;
• at least one venting slot;
• an elongate shaft extending from the cannula upper housing;
• a first lumen extending through the cannula upper housing and the elongate shaft, the first lumen comprising a first lumen inlet and a first lumen outlet, the first lumen configured to receive the insufflation gases from the gas entry port and deliver the insufflation gases from the first lumen outlet proximate a distal end of the elongate shaft and into the surgical cavity, wherein the first lumen inlet is in fluid communication with a source of the insufflation gases through the gas entry port, and wherein the first lumen is configured to receive the medical instrument therethrough;
• and
• a second lumen extending through the cannula upper housing and the elongate shaft, the second lumen comprising a second lumen inlet and a second lumen outlet, the second lumen outlet in fluid communication with the at least one venting slot, the second lumen configured to receive the gases through the second lumen inlet from the surgical cavity and vent the gases through the at least one venting slot and through a proximal-facing surface to outside the surgical cavity,
• wherein the first lumen is radially offset with respect to the second lumen,
• wherein the first lumen and the second lumen are non-concentric with respect to each other,
• wherein the first lumen is fluidly isolated from the second lumen such that gases can flow through the first lumen and the second lumen simultaneously,
• wherein the first lumen has a larger cross-sectional area than the second lumen, measured across the elongate shaft transverse to a longitudinal axis of the first lumen, and
• wherein the longitudinal axis of the first lumen intersects with the opening in the cannula upper housing.