A single-use, sterile "anti-fog suction device" (a 4 Fr multi-channel silicone catheter) is introduced through the same nostril alongside the endoscope after induction of anaesthesia.

The built-in micro-balloon is inflated with 1 ml air to anchor the tip in the posterior choana.

Low-flow (2 L min-¹), filtered, room-temperature air is delivered through the central lumen, creating a gentle laminar stream that passes across the lens, continuously removing warm humid air and preventing condensation.

Two side ports provide continuous low-pressure (-5 cmH₂O) suction of any blood or fluid, keeping the surgical field dry.

The device remains in place for the entire operation and is removed before nasal packing. No extra incisions or sutures are required.

Standard care: whenever the lens fogs, the scrub nurse withdraws the endoscope and irrigates its tip with 5-10 ml of 37 °C sterile saline from a 20 ml syringe. This manoeuvre is repeated as often as necessary (average 10-15 times per case).

A single-use, sterile "anti-fog suction device" (a 4 Fr multi-channel silicone catheter) is introduced through the same nostril alongside the endoscope after induction of anaesthesia.

The built-in micro-balloon is inflated with 1 ml air to anchor the tip in the posterior choana.

Low-flow (2 L min-¹), filtered, room-temperature air is delivered through the central lumen, creating a gentle laminar stream that passes across the lens, continuously removing warm humid air and preventing condensation.

Two side ports provide continuous low-pressure (-5 cmH₂O) suction of any blood or fluid, keeping the surgical field dry.

The device remains in place for the entire operation and is removed before nasal packing. No extra incisions or sutures are required.

defined as the cumulative time from the moment the surgeon declares "lens fogged" until clear operative view is restored, measured with a stop-watch by the circulating nurse throughout the entire endoscopic endonasal procedure.

Incidence of post-operative intracranial infection within 7 days (positive CSF culture OR CSF WBC ≥ 10 × 10⁶/L with fever ≥ 38.5 °C).