Paranasal sinuses in children: size evaluation of maxillary, sphenoid, and frontal sinuses by magnetic resonance imaging and proposal of volume index percentile curves.

Our objective was to establish the age-related 3D size of maxillary, sphenoid, and frontal sinuses. A total of 179 magnetic resonance imaging (MRI) of children under 17 years (76 females, 103 males) were included and sinuses were measured in the three axes. Maxillary sinuses measured at birth (mean+/-standard deviation) 7.3+/-2.7 mm length (or antero-posterior)/4.0+/-0.9 mm height (or cranio-caudal)/2.7+/-0.8 mm width (or transverse). At 16 years old, maxillary sinus measured 38.8+/-3.5 mm/36.3+/-6.2 mm/27.5+/-4.2 mm. Sphenoid sinus pneumatization starts in the third year of life after conversion from red to fatty marrow with mean values of 5.8+/-1.4 mm/8.0+/-2.3 mm/5.8+/-1.0 mm. Pneumatization progresses gradually to reach at 16 years 23.0+/-4.5 mm/22.6+/-5.8 mm/12.8+/-3.1 mm. Frontal sinuses present a wide variation in size and most of the time are not valuable with routine head MRI techniques. They are not aerated before the age of 6 years. Frontal sinuses dimensions at 16 years were 12.8+/-5.0 mm/21.9+/-8.4 mm/24.5+/-13.3 mm. A sinus volume index (SVI) of maxillary and sphenoid sinus was computed using a simplified ellipsoid volume formula, and a table with SVI according to age with percentile variations is proposed for easy clinical application. Percentile curves of maxillary and sphenoid sinuses are presented to provide a basis for objective determination of sinus size and volume during development. These data are applicable to other techniques such as conventional X-ray and CT scan.

Closure of large intrathoracic airway defects using extrathoracic muscle flaps.

BACKGROUND: Prospective assessment of pedicled extrathoracic muscle flaps for the closure of large intrathoracic airway defects after noncircumferential resection in situations where an end-to-end reconstruction seemed risky (defects of > 4-cm length, desmoplastic reactions after previous infection or radiochemotherapy). METHODS: From 1996 to 2001, 13 intrathoracic muscle transpositions (6 latissimus dorsi and 7 serratus anterior muscle flaps) were performed to close defects of the intrathoracic airways after noncircumferential resection for tumor (n = 5), large tracheoesophageal fistula (n = 2), delayed tracheal injury (n = 1) and bronchopleural fistula (n = 5). In 2 patients, the extent of the tracheal defect required reinforcement of the reconstruction by use of a rib segment embedded into the muscle flap followed by temporary tracheal stenting. Patient follow-up was by clinical examination bronchoscopy and biopsy, pulmonary function tests, and dynamic virtual bronchoscopy by computed tomographic (CT) scan during inspiration and expiration. RESULTS: The airway defects ranged from 2 x 1 cm to 8 x 4 cm and involved up to 50% of the airway circumference. They were all successfully closed using muscle flaps with no mortality and all patients were extubated within 24 hours. Bronchoscopy revealed epithelialization of the reconstructions without dehiscence, stenosis, or recurrence of fistulas. The flow-volume loop was preserved in all patients and dynamic virtual bronchoscopy revealed no significant difference in the endoluminal cross surface areas of the airway between inspiration and expiration above (45 +/- 21 mm(2)), at the site (76 +/- 23 mm(2)) and below the reconstruction (65 +/- 40 mm(2)). CONCLUSIONS: Intrathoracic airway defects of up to 50% of the circumference may be repaired using extrathoracic muscle flaps when an end-to-end reconstruction is not feasible.