Simulated reflux and laryngotracheal reconstruction: a rabbit model.

OBJECTIVES: (1) To test the feasibility of a rabbit model using a pharyngostomy tube to simulate gastroesophageal reflux and (2) to study the effects of gastroesophageal reflux on laryngotracheal reconstruction using a new rabbit model. DESIGN: Prospective randomized trial. SUBJECTS: Thirty-three New Zealand white rabbits. INTERVENTIONS: Anterior cartilage laryngotracheoplasty and pharyngostomy tube placement into the pyriform sinus were performed in 33 rabbits, 22 of which are included in this analysis. Beginning postoperative day 1, hydrochloric acid at a pH of 1.5 with pepsin (n = 7) or at a pH of 4.0 with pepsin (n = 8) was irrigated twice daily through the pharyngostomy tube to simulate gastroesophageal reflux, and a control group received twice-daily isotonic sodium chloride solution irrigations (n = 7). MAIN OUTCOME MEASURES: Specimens were scored by a pathologist masked to individual groups using a newly modified inflammation scoring system. In addition, cross-sectional areas of the cartilage grafts and subglottic airway lumina were compared. RESULTS: Inflammation scores were significantly higher in rabbits receiving hydrochloric acid and pepsin irrigations at a pH of 4.0 (P =.04) but not in those in the pH 1.5 group. Cartilage necrosis was prominent in all groups, and airway sizes and cross-sectional areas of the grafts were not significantly different among the 3 groups. CONCLUSIONS: Cartilage necrosis is prominent during the early stages after laryngotracheoplasty. Inflammation can be increased using hydrochloric acid and pepsin irrigations but is difficult to predict based on this study. Although we confirmed the feasibility of this model, further modifications of this study are proposed to improve animal survival and data collection.

Endobronchial tumors in children: an uncommon clinical entity.

We performed a retrospective chart review of 10 children in whom endobronchial tumors were diagnosed in a tertiary-care children's medical center from 1988 to 1998. Of the 10 patients, 6 were male and 4 were female (8 white, 1 Hispanic, 1 African American). The mean age at presentation was 5.2 years. Eight tumors were benign, and 2 were malignant; 4 were on the right side, 3 were on the left side, and 3 were bilateral. Histologic findings included 3 bronchial papillomas, 3 inflammatory masses, 1 endobronchial hemangioma, 1 leiomyoma, 1 mucoepidermoid carcinoma, and 1 bronchial carcinoid. Endobronchial tumors in children are a rare disorder. The diagnosis requires a high index of suspicion in children with atypical or chronic respiratory complaints. Newer adjuvant medical therapies and surgical innovations offer improved disease control in these patients, and a multidisciplinary approach is often warranted.

Optimal concentration of epinephrine for vasoconstriction in ear surgery.

OBJECTIVE: To determine the optimal concentration of epinephrine required for vasoconstriction in ear surgery by evaluating changes in laser doppler blood flow. STUDY DESIGN: Prospective, randomized, double-blinded. METHODS: Forty subjects undergoing surgical procedures under general anesthesia were injected in a standard posterior external auditory canal block with 1 mL of 1% lidocaine containing varying concentrations of epinephrine (nil, 1:50,000, 1:100,000, or 1:200,000) determined by randomization. Ear canal blood flow measurements were then made at 1-minute intervals for a 10-minute period using a laser doppler flow meter and compared with baseline blood flow. RESULTS: The control solution of 1% lidocaine had a significantly higher blood flow than the epinephrine-containing solutions with an actual 200% increase in blood flow for the first 5 minutes before returning to baseline. All epinephrine-containing solutions had an approximately 50% decrease in blood flow from baseline over the 10-minute period as compared with the control which was statistically significant (P < .0001). There was no significant difference between the blood flow reduction of 1:50,000, 1:100,000, and 1:200,000 epinephrine-containing solutions (P = .8875). CONCLUSIONS: One percent lidocaine control exhibited the expected initial vasodilatory effect for approximately 5 minutes. In this experimental model, using a lower concentration of 1:200,000 epinephrine would supply equivalent vasoconstriction in the ear compared with higher concentrations, thus reducing the possible systemic toxicity and related morbidity.

Nontraumatic atlantoaxial rotary subluxation in the pediatric otolaryngology patient. A report of four cases.

Nontraumatic atlantoaxial rotary subluxation (NAARS) is a relatively uncommon entity, with inconsistent presentations. It most commonly follows infectious processes or operative procedures. We present our experience with 4 pediatric otolaryngology patients with NAARS who were treated at the University of Iowa Hospitals and Clinics during a 2-year period beginning in 1997. A review of the symptoms, physical findings, and radiographic abnormalities is presented. Treatment options, varying from muscle relaxants to surgical fusion, are discussed. A high index of suspicion in evaluating children with a stiff neck or pain on attempted motion is essential in order to facilitate prompt diagnosis and appropriate intervention.

Effect of pentoxifylline on the healing of guinea pig tympanic membrane.

Although most tympanic membrane perforations heal spontaneously, persistent perforations frequently require treatment by otolaryngologists. Initial management strategies include keeping the ear dry, ensuring aural hygiene, and using topical antibiotics. For persistent perforations, paper patching or myringoplasty may be required. Recently, agents such as hyaluronic acid and epidermal growth factor have been used to promote tympanic membrane healing. Similarly, pentoxifylline, a pharmaceutical agent with hemorrheological and antithrombotic properties, has been shown to increase perfusion and accelerate wound healing. This double-blinded prospective study attempts to examine the effect of pentoxifylline on tympanic membrane healing of 50 guinea pigs subjected to myringotomy. Serial examinations and histopathologic sectioning of the tympanic membranes revealed no significant difference in rate of healing or quality of repair between the pentoxifylline and control groups.

Laryngomalacia and its treatment.

OBJECTIVE: To determine 1) airway outcome of infants with laryngomalacia who do not undergo routine direct laryngoscopy (DL) and bronchoscopy (B), 2) the age at resolution of laryngomalacia, and, 3) outcome of supraglottoplasty as a function of the type of laryngomalacia and the presence of concomitant disease. STUDY DESIGN: Retrospective chart review. METHODS: The records of all infants diagnosed with laryngomalacia by flexible fiberoptic laryngoscopy (FFL) between 1990 and 1998 in the Department of Otolaryngology--Head and Neck Surgery, University of Iowa (Iowa City, IA) were reviewed. The type of laryngomalacia was designated by a new classification scheme (types 1-3) based on the site of supraglottic obstruction and the type of supraglottoplasty indicated, should the patient later require surgical intervention. The log rank test was used to compare age at resolution and outcome between types of laryngomalacia and between infants with isolated laryngomalacia versus those with additional congenital abnormalities and/or severe neurological compromise. RESULTS: The type of laryngomalacia was evident in 48 of the 58 charts reviewed and included type 1 (57%), type 2 (15%), type 3 (13%), or combined types (15%). Twenty percent had severe neurological compromise and/or multiple congenital anomalies. The median time to resolution of stridor in these patients was not significantly delayed when compared with infants who had isolated airway anomalies (36 and 72 wk, respectively, vs. 36 wk for isolated laryngomalacia; P<.4). Time to resolution did not correlate with the type of laryngomalacia. In 22 infants, clinical symptoms or findings suggested a synchronous airway lesion, and direct laryngoscopy and bronchoscopy were performed. In 11 infants, a second airway lesion was diagnosed (in four cases by FFL and in 7 cases by direct laryngoscopy and bronchoscopy). Complications did not arise in infants who did not undergo direct laryngoscopy and bronchoscopy. Eleven infants with severe laryngomalacia required surgical intervention. The success of supraglottoplasty did not correlate with the type of laryngomalacia or the presence of other congenital anomalies. CONCLUSIONS: Routine direct laryngoscopy and bronchoscopy as part of the evaluation of laryngomalacia are not warranted. Performing these procedures should be based on clinical and physical evidence of a concomitant airway lesion. In general, laryngomalacia will resolve within the first year of life, even in children with multiple congenital anomalies and/or severe neurological compromise. The proposed classification scheme is advantageous in that it is simple and correlates the site of obstruction with the surgical procedure most likely to effect a cure, should the patient require a supraglottoplasty. Surgical management is necessary in approximately 15% to 20% of affected infants.

Treatment of lymphangiomas in children: an update of Picibanil (OK-432) sclerotherapy.

Picibanil (OK-432) is a sclerosing agent derived from a low-virulence strain of Streptococcus pyogenes that induces regression of macrocystic lymphangiomas. This report describes a prospective, nonrandomized trial to evaluate the efficacy of Picibanil in the treatment of 13 affected children ranging in age from 1 to 94 months. On average, 4.1 fluoroscopically guided intracystic injections were performed per child, with an average total dose of 0.56 mg of Picibanil. As judged by physical examination and radiographic studies, 5 children (42%) showed a complete or substantial response, and 2 children (16%) showed an intermediate response. No response was seen in 5 children (42%), 2 of whom had massive craniofacial lymphangioma. Factors that contribute to failure with Picibanil sclerotherapy are the presence of a significant microcystic component to the lesion, massive craniofacial involvement, and previous surgical resection. Macrocystic lymphangiomas of the infratemporal fossa or cervical area have the best response to therapy.

Effects of dimethylthiourea, melatonin, and hyperbaric oxygen therapy on the survival of reimplanted rabbit auricular composite grafts.

Microvascular reconstruction currently offers the best chance of survival for an ear segment reimplanted after amputation. Unfortunately, this technique is possible only when ear and scalp vessels remain intact. Direct reattachment of the amputated segment as a composite graft is less reliable because survival is poor for grafts larger than 2 cm in diameter. However, if survival could be improved, direct reattachment would be an attractive alternative in situations in which microsurgical revascularization is not possible. Certain pharmacologic agents have been shown to enhance the survival of composite grafts. This study demonstrated that hyperbaric oxygen, dimethylthiourea, and melatonin significantly affected the survival of reimplanted auricular composite grafts at day 7. However, by day 21 the average percentage of survival for all groups approached 13% to 14%. Dimethylthiourea had the most beneficial effect on survival early in the postoperative period, whereas the hyperbaric oxygen group demonstrated the poorest survival.

An update on the treatment of hemangiomas in children with interferon alfa-2a.

OBJECTIVE: To report the benefits and complications of subcutaneous interferon alfa-2a therapy for hemangiomas in children. DESIGN: Prospective nonrandomized trial. SETTING: Tertiary care pediatric referral center. PATIENTS: Twenty-four pediatric patients diagnosed with massive or life-threatening hemangiomas. INTERVENTIONS: Each patient received daily subcutaneous injections of interferon alfa-2a to a target dose of 3 million U/m2 of body surface area for a minimum of 4 months. Nineteen patients completed therapy and have received adequate follow-up. MAIN OUTCOME MEASURES: Clinical and radiographic comparisons before, during, and after therapy. Reduction in hemangioma size was graded as complete (>90%), substantial (50%-80%), intermediate (20%-40%), or no response (<10%). RESULTS: Mean age at institution of therapy was 9.6 months, and mean duration of treatment was 10.2 months. Most patients (70%) had not received prior therapy. Responses were as follows: complete, 8 patients (42%); substantial, 3 patients (16%), intermediate, 5 patients (26%); and no response, 3 patients (16%) (n = 19). During therapy, 5 patients (26%) developed neurological abnormalities: 3 had an unsteady gait, and 2 had fine motor deficits. Only 1 of these 5 patients required premature termination from the study, and the neurological abnormalities in all 5 patients resolved after treatment was discontinued. Two of the 4 patients with neurological findings who completed therapy demonstrated complete resolution of their hemangiomas. Patients who developed neurological abnormalities began interferon alfa-2a therapy at an earlier age (4.7 months) than patients without neurological difficulties (aged 11.1 months). The mean time from initiation of therapy to the appearance of neurological complications was 4.8 months. CONCLUSIONS: In pediatric patients with massive or life-threatening hemangiomas, interferon alfa-2a therapy is an effective treatment option. However, neurological evaluation before and during therapy with interferon alfa-2a should be performed owing to a significant incidence of neurological abnormalities (28%). Although all children with neurological findings demonstrated neurological recovery after discontinuation of therapy, we have changed our protocol and now more gradually increase the dosage of interferon alfa-2a up to 3 million U/m2 per day. The effect of this modification on the development of neurological abnormalities has not yet been determined.

Identification and mutation analysis of a cochlear-expressed, zinc finger protein gene at the DFNB7/11 and dn hearing-loss loci on human chromosome 9q and mouse chromosome 19.

The DFNB7/11 locus for autosomal recessive non-syndromic hearing loss (ARNSHL) has been mapped to an approx. 1.5 Mb interval on human chromosome 9q13-q21. We have determined the cDNA sequence and genomic structure of a novel cochlear-expressed gene, ZNF216, that maps to the DFNB7/11 interval. The mouse orthologue of this gene maps to the murine dn (deafness) locus on mouse chromosome 19. The ZNF216 gene is highly conserved between human and mouse, and contains two regions that show homology to the putative zinc linger domains of other proteins. To determine it mutations in ZNF216 might be the cause of hearing loss at the DFNB7/11 locus, we screened the coding region of this gene in DFNB7/11 families by direct sequencing. No potential disease-causing mutations were found. In addition, Northern blot analysis showed no difference in ZNF216 transcript size or abundance between dn and control mice. These data Suggest that the ZNF216 gene is unlikely to be responsible for hearing loss at the DFNB7/11 and dn loci.

Localization of a novel gene for nonsyndromic hearing loss (DFNB17) to chromosome region 7q31.

Autosomal recessive nonsyndromic hearing loss (ARNSHL) is the most common form of hereditary hearing impairment (HHI). To date, 16 different loci have been reported, making ARNSHL an extremely heterogeneous disorder. One of these loci, DFNB4, was mapped to a 5-cM interval of 7q31 in a large Middle-Eastern Druze family. This interval also includes the gene for Pendred syndrome. We report on three new families with HHI from the Madras region of southern India that demonstrate linkage to 7q. Their pedigrees are compatible with autosomal recessive inheritance. Furthermore, the largest family identifies a novel locus (DFNB17) telomeric to the DFNB4 and Pendred intervals. A 3-cM region of homozygosity by descent between markers D7S486 and D7S2529 is present in all affected individuals in this family and generates a multipoint LOD score of 4.24. The two other families map to the previously reported DFNB4 region but have insufficient power to attain significant LOD scores. However, mutations in the Pendred syndrome gene are present in one of these families.

Diagnosis and management of middle ear osteomas: a case report and literature review.

Osteomas of the middle ear are exceedingly rare benign neoplasms. To date, 16 cases have been reported in the literature, the vast majority of which appear as middle ear masses in young males with a progressive conductive hearing loss. In most patients, the diagnosis is confirmed by computed tomography (CT) or at the time of surgical exploration. Although these lesions have been described as slow-growing, no long-term follow-up has been reported. We present the seventeenth case of a middle ear osteoma in a 33-year-old man who remains asymptomatic and without evidence of tumor growth after nine years of follow-up. We suggest that asymptomatic middle ear osteomas can be appropriately managed without removal in a select group of patients.

Thoracic duct injury during anterior cervical discectomy: a rare complication. Case report.

Chylous fistula resulting from intraoperative injury to the cervical thoracic duct is well described as a complication of neck dissection. However, injury to the thoracic duct during spinal surgery is rarely reported. The authors present the first case of thoracic duct injury occurring during cervical discectomy and fusion via an anterior approach. The anomalous location of the terminal arch of the thoracic duct in this patient contributed to the complication. The morbidity of chyle leakage is minimized by its early recognition, a thorough understanding of lymphatic system anatomy, and aggressive management of the thoracic duct injury.

Presymptomatic diagnosis of nonsyndromic hearing loss by genotyping.

BACKGROUND: Nonsyndromic hearing loss (NSHL) is the most common type of hereditary hearing impairment (HHI). It is genetically heterogeneous, and although the exact number of genes is not known, 38 loci have been identified. By cloning the relevant genes and studying the function of the encoded proteins at the molecular level, it may be possible to impact the habitation of persons at risk for HHI. Currently, for select families, presymptomatic diagnosis of NSHL by genotyping is possible. OBJECTIVE: To provide presymptomatic diagnosis of HHI to individuals in select families who have participated in linkage studies. DESIGN: In 2 large families with autosomal dominant HHI, genes for NSHL were mapped to chromosomes 6 (DFNA10) and 19 (DFNA4). In each family, the phenotype is one of progressive sensorineural hearing loss that begins in the individual's mid-30s and progresses to a severe-to-profound loss requiring amplification. Presymptomatic diagnosis was requested by, and provided to, 19 at-risk persons in these kindreds. RESULTS: By reconstructing haplotypes through the use of short tandem repeat polymorphisms tightly linked to the disease gene, risk calculations and genetic counseling were provided to these persons. CONCLUSIONS: By simple Mendelian genetics, the risk of inheriting a fully penetrant autosomal dominant NSHL gene from a single affected parent is 50% for each offspring. However, by reconstructing haplotypes in families in which an HHI gene has been localized, this risk can be changed substantially.

Construction of P1-derived artificial chromosome and yeast artificial chromosome contigs encompassing the DFNB7 and DFNB11 region of chromosome 9q13-21.

DFNB7 and DFNB11, two loci for autosomal recessive nonsyndromic hearing loss (ARNSHL), have been mapped to chromosome 9q13-21 in separate consanguineous families. Using a radiation hybrid map, we have determined the correct marker order in the DFNB7/11 region and have demonstrated that the DFNB11 locus resides within a redefined DFNB7 interval. The gene(s) responsible for ARNSHL at these loci resides within an approximately 1 cM interval bounded by markers D9S1806 (centromeric) and D9S769 (telomeric). A recently discovered Indian family confirms the new telomeric boundary. To assist in the identification and cloning of candidate genes, YAC and PAC contigs were constructed. A total of 19 YAC and 23 PAC clones were utilized to span the affected region and ensure double coverage throughout. Twenty-two previously published STSs and 21 new STSs were used to determine marker order and confirm the integrity of the contig. Using a positional cloning strategy we have identified three cochlear expressed genes that map to the DFNB7/11 interval.

Electrocautery versus carbon dioxide laser for uvulopalatoplasty in the treatment of snoring.

Laser-assisted uvulopalatoplasty is a popular method for reducing snoring. Drawbacks are the large initial expense of the laser unit and related equipment and required safety precautions. The equipment required for electrocautery for cautery-assisted uvulopalatoplasty is significantly less expensive to obtain and operate compared with the carbon dioxide laser. Ninety-eight patients were randomly assigned to one of two treatment groups to undergo uvulopalatoplasty: one performed with the carbon dioxide laser and the other with electrocautery. We compared postoperative pain, time off work, efficacy, and the number of treatments required to achieve a satisfactory result. We found no statistically significant difference in any of these parameters between the two treatment groups (P > 0.05). Our data show that the use of the carbon dioxide laser offers no advantage over electrocautery in performing uvulopalatoplasty to treat snoring.

Lipomas of the internal auditory canal.

Lipomas of the internal auditory canal (IAC) are rare, benign neoplasms occurring in the third to fifth decade of life predominately in Caucasian males. Eleven cases of IAC lesions have been previously reported; we report four more. Two of four cases showed atypical findings on preoperative radiographic evaluation. These two patients had surgery. Two patients with small tumors elected for observation with close follow-up. Fat suppression of T1-weighted images on magnetic resonance imaging (MRI) offers the most precise preoperative diagnostic tool of IAC lipomas. Because of the infiltrative nature of these tumors, hearing conservation surgery is unlikely to succeed. We recommend observation for those patients with small tumors and serviceable hearing.