[Congenital laryngeal stridor].

We reviewed the diagnosis, complications and treatment of congenital laryngeal stridor (CLS), in 97 patients who consulted our clinic between 1991 and 2001. The 97 patients were diagnosed with laryngeal malacia (32%), vocal cord paralysis and laryngeal stenosis (22%), a neoplastic disease like hemagioma and papilloma (11%), or cystic disease (7%). The cases with vocal cord paralysis, laryngeal stenosis or laryngeal cysts were usually diagnosed within 2 months of birth based on severe dyspnea. Two of the 31 cases of laryngeal malacia and 2 of the 22 cases of vocal cord paralysis were associated with neuromuscular disorders. Three patients suffered from vocal cord paralysis complicated by laryngeal stenosis. Thirty-three of the 97 cases required a tracheostomy; these 33 cases included the one case of laryngeal papilloma (100%), 9 of the 10 cases of hemangioma (90%), and 18 of the 24 cases of laryngeal stenosis (75%). Since any disorders of the upper airway can potentially induce stridor, establishing an accurate diagnosis is sometimes difficult when stridor is the only presenting symptom. Hence, information on associated symptoms and the past history of the subject is particularly important for an accurate diagnosis. In addition, decisions regarding the course of treatment course require adequate consideration of possible complications.

[Development of resonators for an ESR/NMR hybrid imaging system].

An ESR/NMR resonator for hybrid imaging system was fabricated. It consisted of an ESR resonator, a bridged loop-gap resonator (inner diameter, 43 mm; axial length, 10 mm), and an NMR resonator, an LC circuit of a solenoid coil (inner diameter, 60 mm; axial length, 10 mm) and variable capacitor. The former was located inside the latter. The resonant frequencies of ESR and NMR were 730 and 27 MHz, respectively. An ESR/NMR hybrid spectrometer was constructed for homodyne detection and lock-in detection of ESR and NMR signals. By using the ESR/NMR resonator and spectrometer, CW-ESR, CW-NMR, and pulsed NMR measurements of a phantom that included a physiological saline solution containing a nitroxide radical could be made at the magnetic field of 26 mT and 640 mT.

[Congenital choanal atresia and nasal stenosis].

The most common form of nasal obstruction in neonates is soft tissue edema, but congenital bony nasal anomalies are recognized as an important cause of newborn airway obstruction. We reviewed 20 cases of congenital bony nasal abnormalties such as choanal atresia and nasal stenosis referred to National Children's Hospital between 1996 and 2001. Of the 20, 8 involved choanal atresia (6 bilateral and 2 unilateral) and 12 nasal stenosis (5 nasal cavity stenosis, 2 pyriform aperture stenosis and 5 unknown). Six cases of bilateral choanal atresia and 5 of 12 cases of the nasal stenosis presented severe airway distress. Most cases in respiratory distress required immediate surgical enlargement of nasal cavity and stenting with an endotracheal tube for 4 to 8 weeks. Of 12 with nasal stenosis, 5 with mild nasal obstruction were treated with nasal drops and 3 with mild airway distress required no treatment. Five of 7 (71%) with choanal atresia and 1 of 4 with nasal stenosis (25%) required restenosis of the nasal cavity after stent removal. Restenosis occurred more often in choanal atresia than in nasal atresia. Two of 5 with nasal restenosis required stenting for 1 to 2 months again and 1 of those was followed by stenting for more 4 months. Longer stenting did not prevent choanal from restenosis, however, no standard stenting protocol exists for neonates, highlighting the need for further study.