Pannable endoscope

A method comprising:

• through a portal into a surgical patient, inserting an endoscope, the endoscope comprising:
• a sheath having a distal end, a proximal end, and a longitudinal axis, the sheath's proximal end being configured for mechanical connection to an endoscope handle, the sheath's distal end being closed with a transparent window, the sheath having an outer diameter and an inner lumen having a non-circular inner cross-section;
• a core having an outer cross section, a proximal end, and a distal end, the core's distal end spaced from the core's proximal end for insertion into a body, the core configured to sealingly engage the sheath's inner cross-section to mechanically retain the core within the sheath, sealing engagement with and pushing of the core against the sheath's inner cross-section configured to define a plurality of longitudinal channels for flow of fluids therein, between the sheath and core;
• and
• an imaging chip and illumination source mounted at the core's distal end and arranged in a viewing direction through the transparent window;
• conductors to carry power to the imaging chip, and conductors to carry video signal from the imaging chip to the handle;
• the endoscope configured to protect electrically-operated components from the fluids.