Advanced practice providers and children's hospital-based pediatric otolarynology practices

INTRODUCTION

Advanced practice providers (APPs), including nurse practitioners and physician assistants, have been deployed in children's hospital-based academic pediatric otolaryngology practices for many years. However, this relationship in terms of prevalence, roles, financial consequences and satisfaction has not been examined. The objective of this study is to explore how APPs impact healthcare delivery in this setting.

METHODS

Pediatric otolaryngology chiefs of all academic children's hospitals in the US were electronically surveyed about the ways APPs intersected clinically and financially in their respective practice.

RESULTS

A total of 29 of 36 children's hospital-based pediatric otolaryngology practices completed the survey, of which 26 practices (90%) utilized APP. There were large variances within the APP practice cohort in faculty size (mean/median/range = 9.4/8.5/3-29); annual patient visits (mean/median = 18,373/17,600); number of practice site (mean/median/range = 4.3/4/2-9) and number of outpatient APP (mean/median/range = 6.3/5/1-30). No factors (faculty size, annual visits and number of practice sites) differentiated between the APP and non-APP practices. Among APP practices, significant correlation (p<.00001) was observed between size of APP cohort to faculty size and annual visits. 69% of the practices did not differentiate job functions of nurse practitioners and physician assistants. 85% of the practices utilized APPs in all practice sites and 19% utilized APPs in the operating room. 77% of APPs billed independently and 46% had on-site supervision. The most prevalent APP salary bracket based on 0-5, 6-10 and > 11 years of tenure were $76-100K (65%), $100-150K (77%) and $100-150K (86%), respectively. In 46% of the practices, APPs were able to generate enough revenue to cover more than 75% of their salary and 23% of practices generated a profit. 81% of the chiefs ranked the effectiveness of APPs as high (4 and 5) on a 5-point Likert scale.

DISCUSSION

The majority of academic pediatric otolaryngology practices employed APPs. Despite the diversity seen in practice complexity, APP functionality and financial impact, most found the APP model to be beneficial in improving patient care, patient access and faculty productivity.

Complete Tracheal Ring Deformity. A Translational Genomics Approach to Pathogenesis

Rationale: Complete tracheal ring deformity (CTRD) is a rare congenital abnormality of unknown etiology characterized by circumferentially continuous or nearly continuous cartilaginous tracheal rings, variable degrees of tracheal stenosis and/or shortening, and/or pulmonary arterial sling anomaly.Objectives: To test the hypothesis that CTRD is caused by inherited or de novo mutations in genes required for normal tracheal development.Methods: CTRD and normal tracheal tissues were examined microscopically to define the tracheal abnormalities present in CTRD. Whole-exome sequencing was performed in children with CTRD and their biological parents ("trio analysis") to identify gene variants in patients with CTRD. Mutations were confirmed by Sanger sequencing, and their potential impact on structure and/or function of encoded proteins was examined using human gene mutation databases. Relevance was further examined by comparison with the effects of targeted deletion of murine homologs important to tracheal development in mice.Measurements and Main Results: The trachealis muscle was absent in all of five patients with CTRD. Exome analysis identified six de novo, three recessive, and multiple compound-heterozygous or rare hemizygous variants in children with CTRD. De novo variants were identified in SHH (Sonic Hedgehog), and inherited variants were identified in HSPG2 (perlecan), ROR2 (receptor tyrosine kinase-like orphan receptor 2), and WLS (Wntless), genes involved in morphogenetic pathways known to mediate tracheoesophageal development in mice.Conclusions: The results of the present study demonstrate that absence of the trachealis muscle is associated with CTRD. Variants predicted to cause disease were identified in genes encoding Hedgehog and Wnt signaling pathway molecules, which are critical to cartilage formation and normal upper airway development in mice.

Efficacy and Safety of Sirolimus in the Treatment of Complicated Vascular Anomalies

BACKGROUND AND OBJECTIVES

Complicated vascular anomalies have limited therapeutic options and cause significant morbidity and mortality. This Phase II trial enrolled patients with complicated vascular anomalies to determine the efficacy and safety of treatment with sirolimus for 12 courses; each course was defined as 28 days.

METHODS

Treatment consisted of a continuous dosing schedule of oral sirolimus starting at 0.8 mg/m(2) per dose twice daily, with pharmacokinetic-guided target serum trough levels of 10 to 15 ng/mL. The primary outcomes were responsiveness to sirolimus by the end of course 6 (evaluated according to functional impairment score, quality of life, and radiologic assessment) and the incidence of toxicities and/or infection-related deaths.

RESULTS

Sixty-one patients were enrolled; 57 patients were evaluable for efficacy at the end of course 6, and 53 were evaluable at the end of course 12. No patient had a complete response at the end of course 6 or 12 as anticipated. At the end of course 6, a total of 47 patients had a partial response, 3 patients had stable disease, and 7 patients had progressive disease. Two patients were taken off of study medicine secondary to persistent adverse effects. Grade 3 and higher toxicities attributable to sirolimus included blood/bone marrow toxicity in 27% of patients, gastrointestinal toxicity in 3%, and metabolic/laboratory toxicity in 3%. No toxicity-related deaths occurred.

CONCLUSIONS

Sirolimus was efficacious and well tolerated in these study patients with complicated vascular anomalies. Clinical activity was reported in the majority of the disorders.

Multicenter Evaluation of the Effectiveness of Systemic Propranolol in the Treatment of Airway Hemangiomas

Objective

To evaluate the effectiveness of systemic propranolol in airway infantile hemangioma (AIH) treatment.

Design

Case series with chart review.

Participants

Patients with AIH treated with propranolol between 2009 and 2012 with at least a 1-year follow-up.

Outcomes

Presenting age, treating institution, syndrome presence, presenting AIH stage, endoscopy status, propranolol initiation location/dose/duration, time to stridor resolution, adjunctive medical and surgical therapy, and treatment-associated complications.

Results

Twenty-seven patients met inclusion criteria. Average age of diagnosis was 2.3 months (range, 1-5 months). The AIHs were stage 1 in 7 of 27 (26%), stage 2 in 12 of 27 (44%), and stage 3 in 8 of 27 (30%). Propranolol initiation was inpatient in 25 of 27 (93%) and outpatient in 2 of 27 (7%). Propranolol dose was maintained at 2 mg/kg/d in all patients for a minimum of 7 months (range, 7-34 months; median, 15 months). Stridor was eliminated within 24 hours or less of propranolol initiation in 23 of 27 (85%). At diagnosis, staging and propranolol initiation in 11 of 27 (41%) were managed with propranolol alone; the remaining 16 of 27 (59%) also had a steroid injection. The use of adjuvant therapy at the time of propranolol initiation and the size of the AIH were not statistically correlated. Twelve patients had additional treatments after the initiation of propranolol due to recurrence of respiratory symptoms, 1 of 27 (4%) of whom was considered a nonresponder. No complications related to propranolol use were noted.

Conclusions

This multisite study of AIH treatment with propranolol demonstrates similar effectiveness to surgical treatment modalities. Propranolol therapy for AIH had no complications, had potentially lower resource utilization, and should be considered a first-line AIH treatment.

Standardized Outcome and Reporting Measures in Pediatric Head and Neck Lymphatic Malformations

Objective

To develop general and site-specific treatment effect and outcome measures to standardize the reporting of head and neck lymphatic malformation (HNLM) treatments.

Study Design

Consensus statement/expert opinion.

Setting

Multiple tertiary academic institutions.

Subjects and Methods

The modified Delphi method is an iterative process of collecting expert opinions, refining opinions through discussion and feedback, statistically aggregating opinions, and using these aggregates to generate consensus opinion in the absence of other data. The modified Delphi method was used by a multi-institutional group of otolaryngology and interventional radiology experts in the field of vascular anomalies to formulate a list of recommended reporting outcomes for the study and treatment of head and neck lymphatic malformations.

Results

Through 3 rounds of iteration, 10 expert panelists refined 98 proposed outcome measures and 9 outcome categories to a final consensus set of 50 recommended outcome measures in 3 global categories (general, demographics, and treatment complications) and 5 site-specific categories (orbit, oral cavity, pharynx, larynx, and neck).

Conclusions

We propose the first consensus set of standardized reporting measures for clinical and treatment outcomes in studies of HNLMs. Consistent outcome measures across future studies will facilitate comparison of treatment options and allow systematic review. We hope that these guidelines facilitate the design and reporting of subsequent HNLM studies.

Congenital salivary gland anlage tumor - in utero and postnatal imaging

We present a case of an infant with congenital salivary gland anlage tumor, with fetal and postnatal imaging. To the best of our knowledge, this is the first case describing the in utero imaging findings of salivary gland anlage tumor. A fetal MRI was performed secondary to the clinical finding of polyhydramnios, which identified a nasopharyngeal mass. Because findings were concerning for airway obstruction, the fetus was delivered by ex utero intrapartum treatment (EXIT) to airway procedure. A postnatal CT confirmed the findings of the fetal MRI. The lesion was resected when the baby was 4 days old and recovery was uneventful.

Lymphatic malformations: diagnosis and management

Lymphatic malformations are benign vascular lesions that arise from embryological disturbances in the development of the lymphatic system. They encompass a wide spectrum of related abnormalities, including cystic lymphatic lesions, angiokeratoma, lymphatic malformations that occur in bones (Gorham-Stout Syndrome), lymphatic and chylous leak conditions, and lymphedema. This article will focus only on lymphatic malformation mass lesions, whereas other related disease entities will be covered elsewhere in this journal issue. Lymphatic malformations occur frequently in lymphatic-rich areas such as the head and neck region, but they can also be found on any anatomical site in the body. In general, lymphatic malformations are categorized into macrocystic, microcystic, or combined depending on the size of the cysts contained within the lesion. Lymphatic malformations can cause both deformation of the anatomical site involved and functional deficits. The goal of this article is to discuss the etiology, epidemiology, treatment modalities, and comorbidities associated with lymphatic malformations.

Tracheal agenesis with tracheoesophageal fistulae: fetal MRI diagnosis with confirmation by ultrasound during an ex utero intrapartum therapy (EXIT) delivery and postdelivery MRI

Tracheal agenesis is a rare and essentially lethal anomaly with divergent prenatal imaging findings depending on the presence or absence of a tracheoesophageal fistula. All prenatally diagnosed cases of tracheal agenesis reported to date have not had a tracheoesophageal fistula and presented with thoracoabdominal findings similar to congenital high airway obstruction syndrome. We present the case of a 32-week gestation fetus with rapid onset of polyhydramnios and no persistent findings of congenital high airway obstruction syndrome that was ultimately diagnosed with tracheal agenesis plus tracheoesophageal fistula by fetal MRI. Additionally, we present the novel uses of intraoperative US during a staged ex utero intrapartum therapy delivery and postdelivery MRI, facilitated by proximity within the neonatal ICU, to confirm diagnosis and direct patient management while minimizing unnecessary investigations.

Antihypertensive drug-induced angioedema causing upper airway obstruction in children

OBJECTIVE

Angioedema is a well-described complication arising from the use of antihypertensive agents in the adult population. However, its occurrence and potential for upper airway compromise in pediatrics has only been sporadically reported in the literature. Our objective is to report and review the occurrence of antihypertensive-induced angioedema in the pediatric population and the potential for airway compromise.

METHODS

Charts of 42 patients admitted to Cincinnati Children's Hospital Medical Center with the discharge diagnosis of angioedema (ICD-9 code 995.1) from January 2000 to January 2010 were reviewed. Of the 42 charts, 3 cases had angioedema induced by antihypertensive drugs and all 3 resulted in upper airway obstruction. Summary and findings of the data collected from the medical chart review included demographics, chief complaint(s), past medical history, hospital course, antihypertensive drugs used, diagnostic test(s), medical treatment, and time from onset of symptoms to resolution. In addition, a PubMed literature search using the terms angioedema and antihypertensive drugs was performed to review its occurrence in pediatrics. The previous literature case reports were compared to our cases to further characterize and emphasize the clinical features of this occurrence in children and adolescents.

RESULTS

Despite the well-known occurrence of antihypertensive drug-induced angioedema causing airway obstruction in adults, only 4 case reports have been previously published in children. At our institution, we describe 3 children who developed acute angioedema with upper airway obstruction after the chronic use of antihypertensive medications [2 drugs in the ACE inhibitor class (enalapril and lisinopril), and 1 drug in the calcium channel blocker class (CCB; amlodipine)]. In all 3 cases, the symptoms resolved within 1 week after the antihypertensive agent was discontinued.

CONCLUSION

Upper airway obstruction can occur at any age when taking antihypertensive drugs. Particular caution should be applied to ACE inhibitors and CCBs in this regard. With the increasing use of antihypertensive agents in the pediatric population, clinicians should be alert to the possibility of angioedema with upper airway obstruction as a potential lethal adverse effect.

Neonates with Tongue-Based Airway Obstruction

Objective. In this systematic review, the authors summarize the current evidence in the literature regarding diagnosis, treatment, and long-term outcomes in neonates with tongue-based airway obstruction (TBAO) and assess the level of evidence of included studies.

Data Sources. The terms Pierre Robin syndrome/sequence, micrognathia, retrognathia, and cleft palate were combined with airway obstruction, treatment, tongue-lip plication, and osteogenesis distraction to perform an Ovid literature search, yielding 341 references. The authors excluded references containing patients with isolated choanal/nasal obstruction, patients older than 12 months, and expert opinion papers, yielding 126 articles.

Review Methods. The authors searched 3 electronic databases and reference lists of existing reviews from 1980 to October 2010 for articles pertaining to the diagnosis, treatment, and outcomes of TBAO. Reviewers assigned a level of evidence score based on Oxford’s Centre for Evidence Based Medicine scoring system and recorded relevant information.

Results. Most studies were case studies and single-center findings. The lack of standardization of diagnostic and treatment protocols and the heterogeneity of cohorts both within and between studies precluded a meta-analysis. There was little evidence beyond expert opinion and single-center evaluation regarding diagnosis, treatment, and long-term outcomes of neonates with TBAO.

Conclusions. The variability in the phenotype of the cohorts studied and the absence of standardized indications for intervention preclude deriving any definitive conclusions regarding diagnostic tools to evaluate this patient population, treatment choices, or long-term outcomes. A coordinated multicenter study with a standardized diagnostic and treatment algorithm is recommended to develop evidence for the diagnosis and treatment of neonates with TBAO.

Use of sentinel node biopsy for staging parameningeal rhabdomyosarcoma

Identification of nodal involvement is important for treatment planning in patients with rhabdomyosarcoma, and is facilitated by sentinel node biopsy. Although it is employed primarily for extremity tumors, we report using sentinel node biopsy in a patient with parameningeal rhabdomyosarcoma arising in the ethmoid sinus. Lymphoscintigraphy with single photon emission computed tomography following injection of tracer at the tumor site helped identify contralateral cervical node involvement not previously recognized by physical exam, cross sectional imaging, or other functional imaging. This case demonstrates how information from sentinel node identification and biopsy can change therapy recommendations in patients with parameningeal rhabdomyosarcoma.

Comprehensive Airway Management of Neonatal Head and Neck Teratomas

Objectives. To determine the success of initial airway management and to characterize late airway-related complications in patients with airway obstruction due to congenital head and neck teratomas

Study Design. Case series with chart review.

Setting. Tertiary airway referral institution.

Subjects and Methods. Review of consecutive patients with congenital head and neck teratomas from 1988 to 2010. Variables examined include initial airway stabilization at time of birth and perinatal airway management. Outcomes include short- and long-term complications.

Results. Fourteen cases were reviewed. In 12 patients, initial airway management was accomplished on placental support with either intubation or tracheotomy. Two vaginal births required subsequent uncomplicated oral intubation within 24 hours. Nine patients required tracheotomy (3 within the delivery suite, 2 during mass excision on day of life 6 and 24, and the remaining 4 occurred at days 29, 32, 92, and 100). Five deaths occurred, 4 within several days of birth due to complications related to the cervical teratomas and 1 on day of life 32 due to an airway-related complication. Follow-up for surviving patients ranged from 1 month to 18 years. Long-term airway complications ranged from vocal cord paralysis to stenosis requiring laryngotracheoplasty.

Conclusion. This study demonstrates that a multidisciplinary team and a standardized approach in the operating suite have led to successful initial airway stabilization. Furthermore, this study demonstrates the need for continued airway management after delivery. Reassessment of the airway after delivery and an airway management planning meeting with the multidisciplinary team may help decrease morbidity and mortality.

Developmental aspects of the upper airway: report from an NHLBI Workshop, March 5-6, 2009

The upper airway serves three important functions: respiration, swallowing, and speech. During development it undergoes significant structural and functional changes that affect its size, shape, and mechanical properties. Abnormalities of the upper airway require prompt attention, because these often alter ventilatory patterns and gas exchange, particularly during sleep when upper airway motor tone and ventilatory drive are diminished. Recognizing the relationship of early life events to lung health and disease, the National Heart, Lung, and Blood Institute (NHLBI), with cofunding from the Office of Rare Diseases (ORD), convened a workshop of extramural experts, from many disciplines. The objective of the workshop was: (1) to review the state of science in pediatric upper airway disorders; (2) to make recommendations to the Institute to fill knowledge gaps; (3) to prioritize new research directions; and (4) to capitalize on scientific opportunities. This report provides recommendations that could facilitate translation of basic research findings into practice to better diagnose, treat, and prevent airway compromise in children.

Fibroblast growth factor 18 gives growth and directional cues to airway cartilage

OBJECTIVES/HYPOTHESIS

The majority of congenital airway anomalies arise from deficits in the respiratory tract cartilage, emphasizing the importance of this cartilage to the form and function of the upper airway. The primary objective of this study was to characterize molecular mechanisms that regulate rate and direction of chondrocyte growth in the larynx and trachea. Our hypothesis for this study was that fibroblast growth factor 18 (FGF18) provides proliferative and directional cues to the developing laryngeal and tracheal cartilage in the mouse by up-regulating the cartilage-specifying gene, Sox9.

STUDY DESIGN

Molecular genetic and histological analyses of gene expression and cartilage growth in a mouse model.

METHODS

Controlled mating of wild-type FVB/N (Friend Virus B-type/NIH mouse) mice and FGF18 overexpressing mice were carried out, and embryos ranging from embryonic (E) day 10.5 to E18.5 were obtained. The respiratory tract, including the larynx, trachea, and lung, was removed through meticulous dissection, and subjected to whole-mount in situ hybridization with RNA probes, or was sectioned and subjected to immunohistochemistry. Respiratory tracts from FVB/N mice were grown in culture in the presence of exogenous FGF18 or known inhibitors of the FGF pathway, and then subjected to quantitative reverse transcriptase polymerase chain reaction to measure the expression of cartilage-specific genes.

RESULTS

The upper respiratory tract begins as a simple out-pouching from the ventral foregut endoderm at E10.5. The chondrocytes that form the cartilaginous structures of the upper respiratory tract are located at the junction of the respiratory tract out-pouching and the ventral foregut endoderm. This population of chondrocytes then undergoes directional proliferation to eventually assume the mature three-dimensional configuration of the upper respiratory tract cartilaginous framework. Immunohistochemical localization of extracellular signal-regulated kinases, a known modulator of FGF signaling, demonstrated the presence of this enzyme at the periphery of growing cartilage. Explants of larynx-trachea-lung grown in culture with exogenous FGF18 demonstrated hyperplastic growth and directed growth towards the FGF18 source. Finally, both FGF18 overexpressing tracheas and tracheas cultured with exogenous FGF18 demonstrated increased expression of the cartilage-specifying gene, Sox9.

CONCLUSIONS

FGF18 provided both directional and proliferative cues to chondrocytes in the developing upper respiratory tract. FGF18 exerted this effect on developing chondrocytes by up-regulating Sox9 expression. Laryngoscope, 2009.

A novel murine model for the examination of experimental subglottic stenosis

OBJECTIVE

To develop a novel mouse model of acquired subglottic stenosis (SGS) using heterotopic transplanted laryngotracheal complexes (LTCs).

DESIGN

Pilot randomized controlled animal study.

SUBJECTS

Forty-eight C57BL/6 mice.

INTERVENTIONS

Twenty-four donor C57BL/6 mice underwent LTC harvesting. The LTCs were then implanted deep to a cutaneous dorsal flap in 24 allogenic recipients. Sixteen LTCs underwent direct subglottic injury before transplantation, while 8 control LTCs were transplanted without injury. Transplanted LTCs were harvested 1, 2, 3, and 4 weeks after surgery. Tissues were fixed and cut transversely in 6-microm sections from the larynx to the second tracheal ring. Movat pentachrome staining was performed for connective tissue and morphometric analysis. Digital images of the subglottis were captured at x 20 magnification. The thicknesses of the lamina propria and the epithelium were measured at 5 random and equally spaced locations within the subglottic lumen. Vascular endothelial growth factor 164 (VEGF 164) and transforming growth factor beta1 (TGF-beta1) immunohistochemistry was performed on representative sections.

RESULTS

Lamina propria thickness was significantly greater in transplanted LTCs 3 and 4 weeks after injury compared with controls (P = .03, P = .01, respectively). Combined results (groups harvested at 1-4 weeks) revealed a significant difference between all 8 control animals and all 16 experimental animals (P < .001). Epithelial thickness was also greater in the transplanted LTCs 2, 3, and 4 weeks after injury to the subglottis compared with controls (P = .04 for weeks 2 through 4). Movat pentachrome staining showed random distributions and high concentrations of connective tissue within the lamina propria of the subglottis. The VEGF 164 and TGF-beta1 staining patterns were consistent with previous in vivo models of SGS.

CONCLUSION

Heterotopic transplanted LTCs in mice can provide an inexpensive and flexible model for experimental investigation of acquired SGS.

Multicenter interrater and intrarater reliability in the endoscopic evaluation of velopharyngeal insufficiency

OBJECTIVE

To explore interrater and intrarater reliability (R (inter) and R (intra), respectively) of a standardized scale applied to nasoendoscopic assessment of velopharyngeal (VP) function, across multiple centers.

DESIGN

Multicenter blinded R (inter) and R (intra) study.

SETTING

Eight academic tertiary care centers.

PARTICIPANTS

Sixteen otolaryngologists from 8 centers.

MAIN OUTCOME MEASURES

Raters estimated lateral pharyngeal and palatal movement on nasoendoscopic tapes from 50 different patients. Raters were asked to (1) estimate gap size during phonation and (2) note the presence of the Passavant ridge, a midline palatal notch on the nasal surface of the soft palate, and aberrant pulsations. Primary outcome measures were R (inter) and R (intra) coefficients for estimated gap size, lateral wall, and palatal movement; kappa coefficients for the Passavant ridge, a midline palatal notch on the nasal soft palate, and aberrant pulsations were also calculated.

RESULTS

The R (inter) coefficients were 0.63 for estimated gap size, 0.41 for lateral wall movement, and 0.43 for palate movement; corresponding R (intra) coefficients were 0.86, 0.79, and 0.83, respectively. Interrater kappa values for qualitative features were 0.10 for the Passavant ridge; 0.48 for a notch on the nasal surface of the soft palate, 0.56 for aberrant pulsations, and 0.39 for estimation of gap size.

CONCLUSIONS

In these data, there was good R (intra) and fair R (inter) when using the Golding-Kushner scale for rating VP function based on nasoendoscopy. Estimates of VP gap size demonstrate higher reliability coefficients than total lateral wall, mean palate estimates, and categorical estimate of gap size. The reliability of rating qualitative characteristics (ie, the presence of the Passavant ridge, aberrant pulsations, and notch on the nasal surface of the soft palate) is variable.

Reflux symptom index versus reflux finding score

OBJECTIVES

We examined the correlation between the Reflux Symptom Index (RSI) and the Reflux Finding Score (RFS) to determine the laryngeal signs and symptoms that were most significantly correlated.

METHODS

Forty randomly selected patients were included in the study. A retrospective chart review was performed for patients who fit the inclusion criteria. Videostroboscopic samples for the study group were reviewed and RFS-rated by 6 experienced raters on 2 different occasions to evaluate the interrater and intrarater reliability. The RSI and the RFS were statistically compared regarding both the total scores and the individual parameters.

RESULTS

The RFS ranged from 0 to 20, and the RSI varied from 14 to 38. There was a high agreement between the raters' scores, demonstrating high interrater and intrarater reliability for RFS. Additionally, the RSI and RFS were highly correlated (p < .0001). Hoarseness was highly correlated with vocal fold edema and thick laryngeal mucus (p < .01), and excessive throat clearing correlated significantly with thick endolaryngeal mucus (p < .01).

CONCLUSIONS

The study demonstrates a highly significant correlation between the RFS and the RSI.

Changes in the Cricoarytenoid Joint Induced by Intubation in Neonates

OBJECTIVE

To characterize the histopathologic characteristics of the cricoarytenoid joint (CAJ) as a means to understand the mechanisms of vocal cord fixation in children after prolonged intubation.

DESIGN

Histologic analysis of laryngeal specimens obtained from infants who had died secondary to various causes and who had been intubated from 1 to 30 days.

MAIN OUTCOME MEASURE

Histopathologic characteristics of CAJ.

RESULTS

Laryngeal specimens from infants who had been intubated for prolonged periods of time demonstrated evidence of hemorrhage, infection, inflammation, and fibrosis within the CAJ. Furthermore, a statistical correlation was found between the length of intubation and the presence of these histologic abnormalities.

CONCLUSIONS

To our knowledge, this is the first study to demonstrate histologic changes in the CAJ in laryngeal specimens of children who have been intubated for prolonged periods of time. Such histological changes in the CAJ could explain the mechanism of vocal cord immobility in children after intubation.

Adenotonsillectomy for obstructive sleep apnea syndrome in young children: prevalence of pulmonary complications

OBJECTIVE

To determine, in a series of children younger than 6 years undergoing adenotonsillectomy for treatment of clinical obstructive sleep apnea syndrome (OSAS), the effect of age on prevalence of postoperative respiratory complications. The primary objective was to define a practice standard for postoperative hospital admission.

DESIGN

Retrospective analysis.

SETTING

Cincinnati Children's Hospital Medical Center, Cincinnati, Ohio.

PATIENTS

All children younger than 6 years who underwent adenotonsillectomy to treat OSAS from June 1, 1999, to May 31, 2001.

MAIN OUTCOME MEASURES

The percentage of children younger than 3 years undergoing adenotonsillectomy to treat OSAS who experience a postoperative respiratory complication.

RESULTS

Of 2315 patients younger than 6 years undergoing an adenotonsillectomy for treatment of OSAS, 149 (6.4%) developed a postoperative respiratory complication. Even though there was a lower incidence of comorbid medical conditions in this cohort, children younger than 3 years were at a greater risk for developing a postoperative respiratory complication compared with those aged 3 to 5 years (9.8% vs 4.9%, P<.001). Logistic regression analysis revealed that children younger than 3 years had a nearly 2-fold increased risk for respiratory complications postoperatively (odds ratio, 1.98; 95% confidence interval, 1.41-2.77) when controlling for race and sex.

CONCLUSIONS

Adenotonsillectomy to treat OSAS is associated with a significantly higher rate of postoperative respiratory complication in children younger than 3 years compared with children aged 3 to 5 years. Our results support hospital admission for all patients younger than 3 years undergoing adenotonsillectomy for treatment of OSAS.

Cervicofacial vascular anomalies. II. Vascular malformations

Vascular malformations are the second major category of vascular anomalies. In contrast to vascular tumors, they are present at birth and grow commensurately with the child. Although the molecular mechanisms underlying the formation of these lesions remain unclear, lesions are known to result from abnormal development and morphogenesis. Histologic examination of vascular malformations shows no evidence of cellular proliferation, but rather progressive dilation of abnormal channels. Vascular malformations are designated according to their predominant channel type; they may be capillary, venous, lymphatic, arterial, and combined malformations. Malformations with an arterial component are rheologically fast-flow, whereas capillary, lymphatic, and venous malformations are slow-flow in nature. The morbidity of vascular malformations varies greatly both within and among the clinical subgroups cited above. This article describes the clinical presentation, diagnosis, and management of vascular malformations. The more frequently encountered clinical presentations involving the head and neck are highlighted.

Down syndrome and complete tracheal rings

Tracheal stenosis caused by complete tracheal rings has previously not been associated with Down syndrome. We identified 7 children with Down syndrome and complete tracheal rings. We found the clinical presentation and airway anatomy to be variable, advocating a heightened level of suspicion when evaluating a child with Down syndrome.

Open Excision of Subglottic Hemangiomas to Avoid Tracheostomy

OBJECTIVE

To assess the efficacy of open excision as an alternative to tracheostomy in the management of subglottic hemangioma.

DESIGN

A retrospective review of patients undergoing open surgical excision of subglottic hemangiomas over a 10-year period.

SETTING

A tertiary pediatric center.

PATIENTS

The study included 22 children ranging in age from 2 to 42 months (median age, 5 months) who underwent open excision of subglottic hemangioma over a 10-year period.

RESULTS

Twenty-one patients were treated with single-stage procedures, with postoperative endotracheal intubation for an average of 5 days. One patient who had a preexisting tracheostomy was treated with a 2-stage procedure and underwent decannulation 2 months after excision. Seven other patients were tracheostomy dependent at the time of excision and underwent decannulation at the time of the procedure. Cartilage grafts were inserted in 10 patients. There were no problems with subglottic stenosis. Twenty-one patients reported good voice and no airway symptoms after a mean follow-up period of 42 months. Five patients had significant postoperative problems. Three patients required further endoscopic procedures for removal of granulation tissue, and 1 patient, who remains minimally symptomatic, developed an anterior glottic web. One patient required a 6-month course of steroids after surgery to treat residual glottic hemangioma.

CONCLUSIONS

Open surgical excision of subglottic hemangiomas can be performed as a single procedure, avoiding a tracheostomy, when modern surgical techniques developed for laryngotracheal reconstruction are incorporated. This approach can avoid repeated endoscopic procedures, prolonged treatment with corticosteroids, and years spent with a tracheostomy waiting for spontaneous involution of the hemangioma.

Pediatric postcricoid vascular malformation: a diagnostic and treatment challenge

Hemangioma of the upper aerodigestive tract is a rarely reported occurrence in the pediatric literature. To date, there have been three published case reports of postcricoid hemangiomas contributing to unexplained dysphagia and respiratory distress. We present three children with a history of swallowing difficulty and stridor who were found to have an occult postcricoid mass. Valsalva maneuvers confirmed the suspicion of a vascular malformation in both patients. Transoral laser therapy (KTP and CO2) was used to ablate the lesions. The patients are symptom-free at 5 months, 5 years, and 2 weeks, respectively. The diagnostic challenge in evaluating these children and the therapeutic choices are described.

Lingual cyst lined by squamous epithelium

Lingual choristomas or foregut duplication cysts are infrequently reported congenital anomalies that typically present in the perinatal period, and can cause respiratory or feeding problems. These cysts are lined by epithelial cells characteristic of the upper aerodigestive tract. We describe two children who presented shortly after birth with lingual cysts lined with squamous epithelium and foci of respiratory epithelium. Unlike previously reported lingual choristomas, these cysts did not contain gastrointestinal epithelium. In both these cases, the lingual cysts were successfully excised via a transoral approach. This article will discuss the histological findings in these two cases, the differential diagnosis and attempt to classify these lesions in the context of existing terminology.

Potential role of Sox9 in patterning tracheal cartilage ring formation in an embryonic mouse model

OBJECTIVE

To identify genes expressed early in the formation of the mouse trachea that control patterning of tracheal cartilaginous rings.

DESIGN

The mouse larynx and trachea begin as an outpouching from the ventral foregut endoderm at embryonic day (E) 9. Digoxigenin-labeled RNA probes to putative tracheal patterning genes were generated by in vitro transcription. Embryos ranging in age from E9 to E16 were then subjected to whole-mount in situ hybridization using these labeled RNA probes. The RNA probes were then localized using antidigoxigenin antibodies tagged with a reporter molecule. In this manner, the 3-dimensional spatial and temporal expression of putative tracheal patterning genes was examined. Subjects F/VBN mice.

RESULTS

In the developing mouse trachea, the expression of Sox9 messenger RNA preceded cartilage ring formation. Sox9 was expressed as 2 distinct longitudinal stripes along the posterolateral aspect of the trachea as early as E9, when the developing trachea is first identified. Collagen 2A1, a cartilage-specific protein, was subsequently expressed in the same longitudinal pattern as Sox9, consistent with the early commitment of Sox9-expressing cells to the cartilage program. As cartilage rings formed, Sox9 and collagen 2A1 was expressed over the lateral and anterior aspects of the trachea.

CONCLUSIONS

We have developed a system to study the early expression of genes that may pattern the formation of the trachea. We have identified a gene (Sox9) with a known role in chondrocyte differentiation that is expressed in a highly specific temporal and spatial pattern in the developing upper respiratory tract.

Electrocautery adenoidectomy compared with curettage and power-assisted methods

OBJECTIVE

To compare electrocautery adenoidectomy with conventional (curettage) and power-assisted (endoscopic shaver) methods.

STUDY DESIGN

Comparative review.

METHODS

Prospective and retrospective studies comparing electrocautery adenoidectomy and conventional curettage or power-assisted methods were reviewed to provide direct comparisons regarding specific outcome variables.

RESULTS

Electrocautery adenoidectomy is a precise, effective technique for removing adenoid tissue. Compared with curettage techniques, electrocautery involves less blood loss and shorter operating times. Power-assisted adenoidectomy also offers shorter operating times and less blood loss, but the necessary equipment is more expensive and more experience is required to attain proficiency with the technique.

CONCLUSION

Electrocautery adenoidectomy provides the benefits of minimization of operating time and blood loss at a lower cost than power-assisted adenoidectomy.

Complications of adenotonsillectomy

OBJECTIVE

To review the immediate, short-term, and long-term complications of adenotonsillectomy.

STUDY DESIGN

Review.

METHODS

Complications of adenotonsillectomy and methods for preventing and treating them were reviewed.

RESULTS

The most common complications of adenotonsillectomy, such as bleeding, generally occur in the immediate perioperative period but can develop up to 2 weeks postoperatively. Long-term complications, such as nasopharyngeal stenosis, may appear months to years after surgery. These more unusual sequelae result from scar contracture and maturation.

CONCLUSION

Although rare, complications associated with adenotonsillectomy can be taxing for patients and health care resources. The most common complications, namely, anesthesia risks, pain, otalgia, and bleeding, should be discussed with patients' caregivers.

Dental implantation for restoration of posttraumatic deformities: avulsion injuries

Soft and hard tissue defects of the cranio- and maxillofacial area, especially after an avulsion injury, are challenging to reconstruct. Sophisticated soft and hard tissue transfer techniques have allowed satisfactory reconstruction of the gross anatomic structure. However, these methods do not allow optimal restoration of fine anatomic detail or function. The advent of dental implants and modified dental implants for craniofacial applications has allowed maximization of cosmetic and functional restoration. Prosthodontists are capable of fabricating subunits of the cranio- and maxillofacial area with fine detail, reproducing the coloring, texture, and idiosyncrasies of a patient's native skin. Dental implant technology has allowed these prostheses to be bone anchored, yielding a reproducible and stable attachment. This method of attachment in turn allows flexibility in the design of the prosthesis, to maximize restoration, and imparts an increased sense of confidence to the patient. Illustrated are six examples demonstrating the versatility of dental implants in the reconstruction of avulsion injuries of the cranio- and maxillofacial complex.

Anterior subannular T-tube for prolonged middle ear ventilation during tympanoplasty: evaluation of efficacy and complications

OBJECTIVE

We previously described the use of anterior subannular T-tubes (n = 20) for long-term middle ear ventilation. In the current study, we examine a larger patient population (n = 38) and a longer follow-up interval (average >2 years) to evaluate the efficacy and safety of anterior subannular tympanostomy.

STUDY DESIGN

Retrospective nonrandomized case review.

SETTING

Tertiary referral hospital.

PATIENTS

Our series consisted of 38 consecutive patients with a diagnosis of eustachian tube dysfunction, adhesive otitis media, or chronic otitis media with a perforation who underwent a tympanoplasty.

INTERVENTION

A subannular T-tube was placed anteriorly at the time of tympanoplasty to provide long-term middle ear ventilation.

MAIN OUTCOME MEASURES

The main outcomes of this study are tube position, tube patency, and middle ear ventilation. In addition, hearing was evaluated both preoperatively and postoperatively and any complications were noted.

RESULTS

There were 38 patients and 38 ears that received an anterior subannular T-tube at the time of tympanoplasty. The study group consisted of 24 female patients and 14 male patents with a median age of 36 years (range, 10-75 yr). All 38 patients had eustachian tube dysfunction, 22 had adhesive otitis media, 23 had chronic otitis media, 13 had a cholesteatoma, 11 had tympanic membrane perforations, and 3 patients had a cleft palate. All patients underwent tympanoplasty. Eighteen patients had a concomitant ossiculoplasty and 7 had a mastoidectomy. Follow-up ranged from 1 month to 48 months (average, 26 mo). Three tubes had extruded within 2 years, in 1 case resulting in a persistent perforation. Postoperative complications included 1 patient with a partially extruded prosthesis, 2 patients with tipped prosthesis and persistent tympanic membrane retraction, and 1 patient with a plugged tube. All other tubes were patent and showed no evidence of migration. Furthermore, there were no cases of anterior canal blunting or ingrowth of epithelium around the tube.

CONCLUSION

Anterior subannular tympanostomy is a safe and effective method for long-term middle ear ventilation in patients with chronic eustachian tube dysfunction.

Fast axonal transport of kinesin in the rat visual system: functionality of kinesin heavy chain isoforms

The mechanochemical ATPase kinesin is thought to move membrane-bounded organelles along microtubules in fast axonal transport. However, fast transport includes several classes of organelles moving at rates that differ by an order of magnitude. Further, the fact that cytoplasmic forms of kinesin exist suggests that kinesins might move cytoplasmic structures such as the cytoskeleton. To define cellular roles for kinesin, the axonal transport of kinesin was characterized. Retinal proteins were pulse-labeled, and movement of radiolabeled kinesin through optic nerve and tract into the terminals was monitored by immunoprecipitation. Heavy and light chains of kinesin appeared in nerve and tract at times consistent with fast transport. Little or no kinesin moved with slow axonal transport indicating that effectively all axonal kinesin is associated with membranous organelles. Both kinesin heavy chain molecular weight variants of 130,000 and 124,000 M(r) (KHC-A and KHC-B) moved in fast anterograde transport, but KHC-A moved at 5-6 times the rate of KHC-B. KHC-A cotransported with the synaptic vesicle marker synaptophysin, while a portion of KHC-B cotransported with the mitochondrial marker hexokinase. These results suggest that KHC-A is enriched on small tubulovesicular structures like synaptic vesicles and that at least one form of KHC-B is predominantly on mitochondria. Biochemical specialization may target kinesins to appropriate organelles and facilitate differential regulation of transport.