CPT® Code 31090

Unilateral sinusotomy, as defined by CPT® Code 31090, involves surgical intervention on three or more of the paranasal sinuses, which include the frontal, maxillary, ethmoid, and sphenoid sinuses. The frontal sinuses are situated in the frontal bone, commonly referred to as the forehead, with one sinus located on each side of the midline. The maxillary sinuses are found within the maxilla, or cheekbones, also with a pair on either side. The ethmoid sinuses are located posterior to the nose and between the eyes, consisting of a collection of 6 to 12 small sinuses or cells on each side. The sphenoid sinus, the most posterior of the paranasal sinuses, is centrally positioned at the base of the skull, with one sinus on each side. Accessing these sinuses can be achieved through various surgical approaches. For the frontal sinuses, a transorbital approach is commonly utilized, while the maxillary sinuses can be accessed via an intranasal route or through the canine fossa intraorally. The ethmoid sinuses may be approached intranasally or extranasally. The sphenoid sinuses require one of three open approaches: transpalatal, transnasal transseptal, or external transorbital transethmoidal. During the procedure, three or more of these sinuses on one side (unilateral) are explored, allowing for the removal of purulent material, diseased tissue, or mucoceles, thereby alleviating symptoms associated with sinus disease.