Comparison of 3 mm versus 4 mm rigid endoscope in diagnostic nasal endoscopy.

Objective: Compare nasal endoscopy with 3 mm versus conventional 4 mm rigid 30° endoscopes for visualization, patient comfort, and examiner ease.

Methods: Ten adults with no previous sinus surgery underwent bilateral nasal endoscopy with both 4 mm and 3 mm endoscopes (resulting in 20 paired nasal endoscopies). Visualization, patient discomfort and examiner's difficulty were assessed with every endoscopy. Sino-nasal structures were checked on a list if visualized satisfactorily. Patients rated discomfort on a standardized numerical pain scale (0-10). Examiners rated difficulty of examination on a scale of 1-5 (1 = easiest).

Results: Visualization with 3 mm endoscope was superior for the sphenoid ostium ( = 0.002), superior turbinate ( = 0.007), spheno-ethmoid recess ( = 0.006), uncinate process ( = 0.002), cribriform area ( = 0.007), and Valve of Hasner ( = 0.002). Patient discomfort was not significantly different for 3 mm 4 mm endoscopes but correlated with the examiners' assessment of difficulty ( = 0.73). The examiner rated endoscopy with 4 mm endoscopes more difficult ( = 0.027).

Conclusions: The 3 mm endoscope was superior in visualizing the sphenoid ostium, superior turbinate, spheno-ethmoid recess, uncinate process, cribriform plate, and valve of Hasner. It therefore may be useful in assessment of spheno-ethmoid recess, nasolacrimal duct, and cribriform area pathologies. Overall, patients tolerated nasal endoscopy well. Though patient discomfort was not significantly different between the endoscopes, most discomfort with 3 mm endoscopes was noted while examining structures difficult to visualize with the 4 mm endoscope. Patients' discomfort correlated with the examiner's assessment of difficulty.