Albaharna, HussainAlrasheed , AbdulazizAlQahtani , AbdulazizPsaltis , AlkisJaver , AminMeco , CemGeorgalas , ChristosWang , EricAlobid , IsamOmura , KazuhiroMacias-Valle , LuisTewfik , MarcPrepageran , NarayananBattaglia , PaoloCastelnuovo , PaoloCarrau , RicardoDouglas , RichardHarvey , RichardCasiano , RoyAhmed, ShahzadaAlsaleh , Saad2025-07-152025-07-152025-03-24Albaharna H, Alrasheed A, AlQahtani A, Psaltis AJ, Javer A, Meco C, Georgalas C, Wang EW, Alobid I, Omura K, Macias-Valle LF, Tewfik M, Prepageran N, Battaglia P, Castelnuovo P, Carrau R, Douglas R, Harvey R, Casiano RR, Ahmed S, Alsaleh S. A Novel International Endoscopic Sphenoid Surgery Classification (IESSC): A Delphi Consensus. Int Forum Allergy Rhinol. 2025 Mar 24:e3572. doi: 10.1002/alr.23572.2042-69762042-6984https://westmid.openrepository.com/handle/20.500.14200/7987Background: Advancements in endoscopic sinus and skull base surgery created a need for standardized terminology to describe sphenoid sinus surgery. Although classification systems exist for other sinuses, one for endoscopic sphenoid sinus surgery is lacking. Developing such a system would standardize procedure descriptions and promote a common language among surgeons. This study aimed to develop a new classification system for endoscopic sphenoid surgery. Methods: Consensus on a novel endoscopic sphenoid surgery classification system by running the Delphi procedure with 16 rhinology experts from around the world. Results: Four Delphi rounds were required to reach a consensus on all stages of the classification. The average percentage of agreement on the stages of classification progressively increased from 70.83% in the first round to 87.68% in the last round. The rejection rates continuously decreased from 8.81% in the first round to 4.44% in the last round. The classification system was developed as follows: stage 1, presphenoid surgery; stage 2A, partial sphenoidotomy; stage 2B, complete sphenoidotomy; stage 2C, transpterygoid sphenoidotomy; stage 3A, Rostral sphenoidectomy; and stage 3B, extended sphenoid drill-out. Conclusions: This novel endoscopic sphenoid surgery classification system facilitates the description of different sphenoid sinus procedures, providing surgeons with better opportunities for discussion and communication.enEar, Nose & ThroatHuman anatomyArticle