Faculty Bibliography

OBJECTIVE: To evaluate the effects of a partial resection of the anterior cricoid arch on the growth of the laryngotracheal complex in an animal model and to study the lumen caliber and cross sectional surface area following resection as the animals are allowed to grow. Laryngeal, subglottic, and tracheal measurements in the infant and pediatric larynges in autopsy specimens are also investigated. DESIGN: A controlled animal study was done comparing the operated rabbit group to the nonoperated group. Twenty-nine infant rabbits were compared to a control group of ten rabbits. In addition, autopsy dissections were performed on infant and pediatric larynges to obtain measurements of various laryngeal and cricoid relationships. METHODS: Thirty-nine pasteurella-free New Zealand white female rabbits between the ages of 8 and 11 weeks were used in this study. In the experimental group, cricotracheal resections were performed by removing the anterior cricoid cartilage and the first tracheal ring. A primary anastomosis was then performed. The animals were kept alive for 4 months and then humanely euthanized. The laryngeal complex was then removed and histological sections of the cricotracheal region were mounted on glass slides and stained with H&E. Measurements were taken of the cricoid and upper tracheal lumen and cross-sectional area. RESULTS: Twenty-seven of the study group survived until the time of sacrifice. All of the control group survived during the study period. The two groups were comparable in regard to weight, lumen size, and cross-sectional area There were no statistical differences between the groups. CONCLUSIONS: The experimental data support the hypothesis that partial cricotracheal resections can be performed safely and effectively in young rabbits. The potential clinical significance is described in light of the autopsy data

Patients undergoing hyperbaric oxygen (HBO2) therapy often experience middle ear barotrauma. Not infrequently this disrupts therapy and may require myringotomy tube placement. A new, simple, office-based procedure known as OtoScan Laser Assisted Myringotomy (OtoLAM) provides temporary middle ear ventilation, which offers significant potential benefis for HBO2 patients. Five patients whose middle ear disease complicated their HBO2 therapy have undergone nine OtoLAM procedures in 11 ears. All patients tolerated the procedure without complications and immediately returned to HBO2 treatment. Based on this preliminary experience, we recommend OtoLAM for selected HBO2 patients with problematic middle ear dysfunction.

OBJECTIVE: To describe our clinical experience with congenital teratomas of the head and neck. STUDY DESIGN: A retrospective review of the six patients as well as a review of the literature in the setting of academic referral centers. METHODS: In six infants with teratomas, four in the cervical region and two arising from the nasopharynx, surgical excision of all tumors was performed. Outcome measures were clinical and radiographic follow-up and the use of a-fetoprotein (AFP) for postoperative monitoring. RESULTS: There was no recurrence of teratomas. CONCLUSIONS: Surgical excision is the treatment for congenital teratomas. Postoperative monitoring for recurrences should include AFP levels in difficult cases.

OBJECTIVE: To demonstrate the potential use of Mitomycin-C (MMC) in the treatment of difficult and recurrent tracheal stenosis. DESIGN: Case series. SETTING: Tertiary care setting. PATIENTS: A retrospective chart review was performed on five pediatric patients with severe, recurrent tracheal granulation and cicatrix after tracheal reconstruction who were treated with topical MMC as an adjunct to bronchoscopy and laser treatment. MMC was applied intraoperatively on saturated pledgets at a dose of 0.1 mg/ml for 2 min to the area where the cicatrix had been lysed. The five patients were able to be decannulated. DISCUSSION: Mitomycin-C is an anti metabolite known to inhibit fibroblast proliferation in vitro. This agent has been used with a high success rate in glaucoma filtration surgery to promote patency of the trabecula. The results of this preliminary application in the pediatric airway as well as the mechanism of action will be discussed.

We review our treatment experience of subglottic stenosis in 66 children. Sixty-one of these children required some form of airway expansion using cartilage grafts. Eight children had grade I (Cotton classification), 15 grade II, 28 grade III, and 15 grade IV stenosis. All patients with grade I and II lesions were decannulated. Ninety-three percent of grade III patients and 67% of grade IV patients were also ultimately decannulated. Laryngotracheal reconstruction with costal cartilage grafting has become widely accepted for treatment of severe laryngotracheal stenosis. Several modifications of this technique have been employed to treat our patients. Recently, we have used a modified single-stage technique with an endotracheal tube stent, externally secured for 1 week, to avoid postoperative intensive care unit admission for sedation and/or paralysis, and its related complications. Posterior graft design and placement without sutures was also performed in 20 cases. A two-surgeon technique that involves a simultaneous endoscopic control of incision of the stenotic area was employed. These modifications will be described in detail.

OBJECTIVE: Evaluate wound healing of incisions created by the scalpel, electrocautery, CO2 laser, and potassium titanyl phosphate (KTP) laser in the upper aerodigestive tract in an animal model. STUDY DESIGN: Prospective randomized study in an animal model. METHODS: Postoperative oral intake, histologic depth of injury, and tensile mechanical strength were measured in rat tongues after creating incisions using a scalpel, electrocautery, CO2 laser, and KTP laser. An unpaired, two-tailed Student's t-test was used to compare results between the experimental groups. RESULTS: Oral intake, indirectly assessed by postoperative weight loss, by the third postoperative day was significantly decreased in the electrocautery (P = 0.004), CO2 laser (P = 0.001), and KTP laser (P = 0.0001) groups as compared with the scalpel group. The depth of the wound healing, as assessed by histologic examination, was successively greater for the scalpel (75 +/- 13 microm), electrocautery (110 +/- 10 microm), CO2 laser (145 +/- 10 microm), and KTP laser (195 +/- 23 microm) groups. However, this difference was only statistically significant for the CO2 laser (P = 0.006) and KTP laser (P = 0.01) groups relative to the scalpel group. Wounds created by the KTP laser had the lowest strength (76.5 +/- 6.9 kPa) as compared with the CO2 laser (156 +/- 28.4 kPa), electrocautery (153 +/- 15.7 kPa), and scalpel groups (249 +/- 61.8 kPa). This difference was only statistically significant for the KTP laser group (P = 0.02) when compared with the scalpel group. CONCLUSIONS: Wounds created in the upper aerodigestive tract of rats by scalpels result in the least postoperative weight loss, tissue destruction, and decrease in tensile strength, whereas wounds created by the KTP laser demonstrated a significantly greater postoperative weight loss, depth of wounding, and decrease in tensile strength

A case of clear-cell follicular adenoma arising in ectopic thyroid tissue is reported. The 2.0-cm tumor arose in the submandibular region in a 29-yr-old female. The diagnosis was established on the basis of light microscopic morphology, a positive thyroglobulin immunohistology, and the presence of normal thyroid tissue surrounding the mass. Preoperative computed tomography (CT) scan and postoperative ultrasound studies revealed a normal orthotopic thyroid gland. No additional tumors have since been detected. The patient is free of recurrent or metastatic disease 54 mo following excision of the mass. Only eight previously published reports have described ectopic thyroid tissue in the submandibular region, all but one of which lacked an orthotopic thyroid gland. In this article, we describe the pathological features of our case and review the existing literature on the subject

Respiratory distress in premature newborns is associated with deficiency of surfactant in the bronchoalveolar lining fluid; this may be influenced by a local deficiency of antioxidants. Severe L-buthionine-S,R-sulfoximine-induced depletion of glutathione (GSH, a major antioxidant) in rodents is associated with lung type 2 cell lamellar body damage and decreased concentrations in lung and bronchoalveolar lavage fluid (BALF) of phosphatidyl choline (a major component of surfactant). At birth, prematurely born newborns (30-34 weeks) had lower peripheral venous plasma GSH concentrations than term (> 36 weeks) babies; these levels decreased further with increasing prematurity (< 27 weeks, with respiratory distress). On day 2, the peripheral venous plasma GSH concentrations reached a nadir, and the lowest levels were found in the most premature newborns. Lymphocyte GSH concentrations were lowest on day 2 and day 7, and in prematures (< 27 weeks, with respiratory distress) remained below adult lymphocyte GSH levels for at least 4 weeks. At birth, prematures (< 27 weeks, with respiratory distress) had a central plasma arterio-venous (A-V) GSH gradient across the lung (an estimate of lung uptake of GSH) of 0.72 +/- 0.15 (mean +/- SD) mumol/L; on day 2, the A-V gradient did not change significantly (0.49 +/- 0.09 mumol/L). At birth, these prematures had markedly decreased BALF GSH concentrations (compared with adult levels), and they were not significantly changed during the first 4 weeks of life. These results suggest that GSH deficiency is present in prematures and that it increases with the degree of prematurity. At birth, GSH deficiency will compromise the lungs' defense against oxidative stress injury. Oxidative stress is likely to increase if hyperoxic treatment is given for respiratory distress in these infants