THE NOSE AND PARANASAL SINUSES
Sphenoidal Sinus. Chronic infection of the sphenoidal sinus may rarely
exist alone, but usually accompanies chronic infection of the ethmoidal
sinuses, especially the posterior ones.
Intranasal operation is seldom performed except for the purpose of
hypophysectomy (p. 87).
External operation is through the same approach as for the ethmoidal cells
which are removed posteriorly until the anterior wall of the sphenoidal sinus
is seen. The anterior sinus wall is then removed and access to the sinus thus