Choanal atresia: a surface and ultrastructural study of the nasal mucous membranes.

Biopsies taken from the anterior two-thirds of the inferior turbinate of 3 female patients affected by unilateral complete choanal atresia were studied at the light, transmission and scanning electron microscope. Several changes, such as the uneveness of the mucosal surface, the thickening of the basal membrane, and the presence of ciliary abnormalities in the respiratory mucosa of the affected cavity, were observed. Ciliary abnormalities consisted of the presence of several 'adhesive' and 'bulging' compound cilia, of cilia with excessive cytoplasm and cytoplasmatic processes, and of ciliary structures with loss of the peripheral membrane. At SEM, cilia of the affected cavity appeared bundled, irregularly oriented, flattened and covered by an increased and/or accumulated secretion. Choanal atresia represents, according to the authors, a chronic suffering condition of the nasal mucous membranes. It is characterized by peculiar aspects which are probably related, on one hand, to the increased and/or accumulated mucous secretions and, on the other, to the congenital and long-standing airflow deprivation.