Fig. 8.

Pathophysiology of difficult airway in Morquio A patients. Both restrictive and obstructive respiratory pathology are common in Morquio A patients. The restrictive defect is due to thoracic cage deformity, and the obstructive defect is from tracheobronchial abnormalities, large tongue and mandible, adenoidal, tonsillar, and vocal cord hypertrophy by accumulation of storage materials. Imbalance of growth between trachea, cervical spine, and brachiocephalic artery causes tracheal obstruction. Moreover, Morquio A patients have small nasal passages caused by thickened mucous membranes and thick and copious secretions. Chronic upper respiratory tract infection further decrease the already diminished airway lumen (adapted from Educational CD for Morquio and permitted by Carol Ann Foundation).