A Pilot Study of Decellularized Cartilage for Laryngotracheal Reconstruction in a Neonatal Pig Model

OBJECTIVE

Severe subglottic stenosis develops as a response to intubation in 1% of the >200,000 neonatal intensive care unit infants per year and may require laryngotracheal reconstruction (LTR) with autologous hyaline cartilage. Although effective, LTR is limited by comorbidities, severity of stenosis, and graft integration. In children, there is a significant incidence of restenosis requiring revision surgery. Tissue engineering has been proposed to develop alterative grafting options to improve outcomes and eliminate donor-site morbidity. Our objective is to engineer a decellularized, channel-laden xenogeneic cartilage graft, that we deployed in a proof-of-concept, neonatal porcine LTR model.

METHODS

Meniscal porcine cartilage was freeze-thawed and washed with pepsin/elastase to decellularize and create microchannels. A 6 × 10-mm decellularized cartilage graft was then implanted in 4 infant pigs in an anterior cricoid split. Airway patency and host response were monitored endoscopically until sacrifice at 12 weeks, when the construct phenotype, cricoid expansion, mechanics, and histomorphometry were evaluated.

RESULTS

The selective digestion of meniscal components yielded decellularized cartilage with cell-size channels. After LTR with decellularized meniscus, neonatal pigs were monitored via periodic endoscopy observing re-epithelization, integration, and neocartilage formation. At 12 weeks, the graft appeared integrated and exhibited airway expansion of 4 mm in micro-CT and endoscopy. Micro-CT revealed a larger lumen compared with age-matched controls. Finally, histology showed significant neocartilage formation.

CONCLUSION

Our neonatal porcine LTR model with a decellularized cartilage graft is a novel approach to tissue engineered pediatric LTR. This pilot study sets the stage for "off-the-shelf" graft procurement and future optimization of MEND for LTR.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:807-814, 2024.

Modulated Fibrosis and Mechanosensing of Fibroblasts by SB525334 in Pediatric Subglottic Stenosis

OBJECTIVE

Subglottic stenosis (SGS) may result from prolonged intubation where fibrotic scar tissue narrows the airway. The scar forms by differentiated myofibroblasts secreting excessive extracellular matrix (ECM). TGF-β1 is widely accepted as a regulator of fibrosis; however, it is unclear how biomechanical pathways co-regulate fibrosis. Therefore, we phenotyped fibroblasts from pediatric patients with SGS to explore how key signaling pathways, TGF-β and Hippo, impact scarring and assess the impact of inhibiting these pathways with potential therapeutic small molecules SB525334 and DRD1 agonist dihydrexidine hydrochloride (DHX).

METHODS

Laryngeal fibroblasts isolated from subglottic as well as distal control biopsies of patients with evolving and maturing subglottic stenosis were assessed by α-smooth muscle actin immunostaining and gene expression for α-SMA, FN, HGF, and CTGF markers. TGF-β and Hippo signaling pathways were modulated during TGF-β1-induced fibrosis using the inhibitor SB525334 or DHX and analyzed by RT-qPCR for differential gene expression and atomic force microscopy for ECM stiffness.

RESULTS

SGS fibroblasts exhibited higher α-SMA staining and greater inflammatory cytokine and fibrotic marker expression upon TGF-β1 stimulation (p < 0.05). SB525334 restored levels to baseline by reducing SMAD2/3 nuclear translocation (p < 0.0001) and pro-fibrotic gene expression (p < 0.05). ECM stiffness of stenotic fibroblasts was greater than healthy fibroblasts and was restored to baseline by Hippo pathway modulation using SB525334 and DHX (p < 0.01).

CONCLUSION

We demonstrate that distinct fibroblast phenotypes from diseased and healthy regions of pediatric SGS patients respond differently to TGF-β1 stimulation, and SB525334 has the superior potential for subglottic stenosis treatment by simultaneously modulating TGF-β and Hippo signaling pathways.

LEVEL OF EVIDENCE

NA Laryngoscope, 134:287-296, 2024.

Anatomic Considerations of esophageal button battery ingestion for outcomes and imaging

INTRODUCTION

Button batteries (BB) are a source of significant morbidity and mortality in young children. Little data is available regarding associations between esophageal impaction location and outcomes or need for surveillance imaging.

METHODS

All patients treated at a single institution following BB ingestion between 2018 and 2022 were included for retrospective chart review.

RESULTS

Twenty patients were treated at our institution BBs were located, or most significant damage observed, in the cervical esophagus (n = 10, 50 %), followed by thoracic esophagus (n = 6, 30 %), and abdominal esophagus (n = 4, 20 %). Patients with cervical esophageal impaction were younger (482 [370-866] days), than those with thoracic (1395 [871-2369] days) or abdominal esophageal impaction (2021.5 [1230.5-3419.5] days) (p = 0.003). Zargar Mucosal Injury Grade was significantly more severe in patients with cervical button battery impaction; 8/10 (80 %) had a ≥Grade IIIB injury, compared to 2/6 (33.3 %) thoracic impactions and 0/4 (0 %) abdominal impactions (p = 0.002). All patients who developed persistent esophageal stenosis (n = 6) had cervical battery impactions (6, 60 %, p = 0.015). Both TEFs (2/2) had anterior facing anode, while both (2/2) esophageal perforations had posterior. Only 1/20 (5 %) patients, and 1/7 (14.3 %) with serious complications, had a serious complication detected on routine, rather than clinically indicated follow-up surveillance.

CONCLUSIONS

In our population, cervical BB impaction occurred more frequently in younger children, was associated with more severe mucosal injury, and had higher risk of stenosis. Nearly all complications were detected on clinically indicated rather than postoperative surveillance imaging.

A multicenter study analyzing the impact of pre-existing comorbidities on laryngotracheal reconstruction (LTR) outcomes

INTRODUCTION

Comorbidities such as chronic lung disease and gastroesophageal reflux (GERD), prematurity, and numerous other conditions may impact the success of LTR. Single-center studies are limited in terms of patient numbers and may be underpowered.

OBJECTIVES

To analyze the impact of specific comorbidities on the operation-specific and overall surgical success of LTR in a large multicenter cohort and validate a predictive model for surgical success.

METHODS

A large retrospective multicenter 10-year review was undertaken to validate the data of a previous single-center study (Wertz et al. Laryngoscope 2020) which identified specific predictive comorbidities which impacted LTR outcomes. A Monte Carlo simulation based on the previous data set suggested that 300-400 cases would be needed to optimize the statistical power of a Bayesian model developed from the single-center data to predict surgical success. An IRB-approved data-sharing agreement was executed for 4 large U.S.

CENTERS

A virtual REDCap® data entry form inquired about patient characteristics that best predicted surgical success in the single-center model. These included demographics, surgical approaches, cardiac, airway, genetic, endocrine, musculoskeletal, gastrointestinal, and pulmonary comorbidities; details of the surgical procedures, and results of esophagogastroduodenoscopy (EGD), esophageal pH/impedance and flexible bronchoscopy with bronchioalveolar lavage (BAL) were included. Surgical success defined as successful decannulation or resolution of airway symptoms was recorded as single surgery success and overall success following open surgical revision surgery. Multivariate Bayesian analysis, logistical regression, and Kaplan-Meier analysis were performed.

RESULTS

542 patients were identified, including 165 from the single-center study and an additional 377 patients from the multicenter group. The median age was 36 months at the time of the most recent surgery. 70.9% of the LTRs were double-staged procedures. The overall success rate was 86.4% and operation-specific success rate was 69.2%. The specific comorbidities and aerodigestive test results that impacted success based on univariate analysis included staging, bronchiectasis, pulmonary hypertension, GERD, ASD, PDA, grade of stenosis, advanced levels of stenosis, Trisomy 21, MRSA, prior open surgery at another hospital, and gross appearance on EGD. Bayesian model averaging with backward selection was used to validate and refine a predictive model for surgical success with favorable receiver operating curve characteristics - AUC values of 0.827 for single surgery success and 0.797 for overall success.

DISCUSSION

With over 500 patients reviewed, this was the largest multicenter study of LTR to date, which elucidated the impact of comorbidities on success with LTR and was able to improve upon the predictive modeling based on single-center data. Patient factors are most critical in the outcome of LTR. Stage and levels of stenosis, as well as pulmonary and GI conditions most strongly impact the likelihood of success. Future prospective case-control studies will be performed to further optimize the current model for outcome prediction and patient management.

Amelioration of Subglottic Stenosis by Antimicrobial Peptide Eluting Endotracheal Tubes

Introduction

Pediatric subglottic stenosis (SGS) results from prolonged intubation where scar tissue leads to airway narrowing that requires invasive surgery. We have recently discovered that modulating the laryngotracheal microbiome can prevent SGS. Herein, we show how our patent-pending antimicrobial peptide-eluting endotracheal tube (AMP-ET) effectively modulates the local airway microbiota resulting in reduced inflammation and stenosis resolution.

Materials and Methods

We fabricated mouse-sized ETs coated with a polymeric AMP-eluting layer, quantified AMP release over 10 days, and validated bactericidal activity for both planktonic and biofilm-resident bacteria against Staphylococcus aureus and Pseudomonas aeruginosa. Ex vivo testing: we inserted AMP-ETs and ET controls into excised laryngotracheal complexes (LTCs) of C57BL/6 mice and assessed biofilm formation after 24 h. In vivo testing: AMP-ETs and ET controls were inserted in sham or SGS-induced LTCs, which were then implanted subcutaneously in receptor mice, and assessed for immune response and SGS severity after 7 days.

Results

We achieved reproducible, linear AMP release at 1.16 µg/day resulting in strong bacterial inhibition in vitro and ex vivo. In vivo, SGS-induced LTCs exhibited a thickened scar tissue typical of stenosis, while the use of AMP-ETs abrogated stenosis. Notably, SGS airways exhibited high infiltration of T cells and macrophages, which was reversed with AMP-ET treatment. This suggests that by modulating the microbiome, AMP-ETs reduce macrophage activation and antigen specific T cell responses resolving stenosis progression.

Conclusion

We developed an AMP-ET platform that reduces T cell and macrophage responses and reduces SGS in vivo via airway microbiome modulation.

Supplementary Information

The online version contains supplementary material available at 10.1007/s12195-023-00769-9.

Vinblastine/Methotrexate for Debilitating and Progressive Plexiform Neurofibroma in Children and Young Adults with Neurofibromatosis Type 1: A Phase 2 Study

Limited therapies exist for neurofibromatosis type 1 (NF1)-associated plexiform neurofibroma (PN). For this reason, the activity of vinblastine (VBL) and methotrexate (MTX) was evaluated in children and young adults with NF1 and PN. Patients ≤ 25 years of age with progressive and/or inoperable NF1-PN received VBL 6 mg/m² and MTX 30 mg/m² weekly for 26 weeks, followed by every 2 weeks for 26 weeks. Objective response rate was the primary endpoint. Of 25 participants enrolled, 23 were evaluable. The median age of participants was 6.6 years (range 0.3-20.7). The most frequent toxicities were neutropenia and elevation of transaminases. On two-dimensional (2D) imaging, 20 participants (87%) had stable tumor, with a median time to progression of 41.5 months (95% confidence interval 16.9, 64.9). Two of eight participants (25%) with airway involvement demonstrated functional improvements including decreased positive pressure requirements and apnea-hypopnea index. A post hoc three-dimensional (3D) analysis of PN volumes was completed on 15 participants with amenable imaging; 7 participants (46%) had progressive disease on or by the end of therapy. VBL/MTX was well-tolerated but did not result in objective volumetric response. Furthermore, 3D volumetric analysis highlighted the lack of sensitivity of 2D imaging for PN response evaluation.

Button battery taping and disposal: Risk reduction strategies for the household setting

OBJECTIVES

Pediatric esophageal button battery (BB) injury occurs rapidly and continues to be a significant source of morbidity and mortality. Unfortunately, a BB that no longer supplies power to a device can still have enough residual voltage to cause injury within the body. Development of additional prevention strategies for consumers may reduce esophageal injury risk.

METHODS

In this study, 24 commercially available button batteries (BBs) were horizontally and vertically wrapped (2 layers, full circumferential coverage, 90° apart) with 6 different types of common household tapes (Scotch®/clear, Scotch®/Magic, masking tape, packing tape/clear, packing tape/brown, black electrical tape) and left at room temperature for 30 days. In addition, 6 of the CR2032 batteries covered with each type of tape were placed in a cadaveric piglet esophageal model for a 4-h period and then compared to controls without tape for tissue pH changes and visible tissue injury.

RESULTS

None of the tape-wrapped batteries showed voltage changes nor presented any hazard stemming from BB ingestion. All 6 tape covered batteries placed in the cadaveric piglet esophageal tissue model demonstrated no visible tissue injury and no change in tissue pH in contrast to the controls. Review of BB packaging language from various brands of commercially available CR2032 batteries showed that none had specific disposal recommendations.

CONCLUSION

Both BB and electronics manufacturers should consider instructing the use of common household tape options to cover these BB immediately after removal from a device for either recycling or disposal. Such precautions may help to reduce related ingestion injuries in children.

Drug-Eluting Endotracheal Tubes for Preventing Bacterial Inflammation in Subglottic Stenosis

OBJECTIVES/HYPOTHESIS

Subglottic stenosis (SGS) results from dysregulated extracellular matrix deposition by laryngotracheal fibroblasts causing scar tissue formation following intubation. Recent work has highlighted a relationship between this inflammatory state and imbalances in the upper airway microbiome. Herein, we engineer novel drug-eluting endotracheal (ET) tubes to deliver a model antimicrobial peptide Lasioglossin-III (Lasio) for the local modulation of the microbiome during intubation.

STUDY DESIGN

Controlled in vitro study.

METHODS

ET tubes were coated with a water-in-oil (w/o) emulsion of Lasio in poly(d,l-lactide-co-glycolide) (PLGA) by dipping thrice. Peptide release was quantified over 2 weeks via fluorometric peptide assays. The antibacterial activity was tested against airway microbes (Staphylococcus epidermidis, Streptococcus pneumoniae, and pooled human microbiome samples) by placing Lasio/PLGA-coated tubes and appropriate controls in 48 well plates with diluted bacteria. Bacterial inhibition and tube adhesion were tested by measuring optical density and colony formation after tube culture, respectively. Biocompatibility was tested against laryngotracheal fibroblasts and lung epithelial cells.

RESULTS

We achieved a homogeneous coating of ET tubes with Lasio in a PLGA matrix that yields a prolonged, linear release over 1 week (typical timeframe before the ET tube is changed). We observed significant antibacterial activity against S. epidermidis, S. pneumoniae, and human microbiome samples, and prevention of bacterial adherence to the tube. Additionally, the released Lasio did not cause any cytotoxicity toward laryngotracheal fibroblasts or lung epithelial cells in vitro.

CONCLUSION

Overall, we demonstrate the design of an effective-eluting ET tube to modulate upper-airway bacterial infections during intubation which could be deployed to help prevent SGS.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2021.

Drug delivery to the pediatric upper airway

Pediatric upper airway disorders are frequently life-threatening and require precise assessment and intervention. Targeting these pathologies remains a challenge for clinicians due to the high complexity of pediatric upper airway anatomy and numerous potential etiologies; the most common treatments include systemic delivery of high dose steroids and antibiotics or complex and invasive surgeries. Furthermore, the majority of innovative airway management technologies are only designed and tested for adults, limiting their widespread implementation in the pediatric population. Here, we provide a comprehensive review of the most recent challenges of managing common pediatric upper airway disorders, describe the limitations of current clinical treatments, and elaborate on how to circumvent those limitations via local controlled drug delivery. Furthermore, we propose future advancements in the field of drug-eluting technologies to improve pediatric upper airway management outcomes.

Current management of button battery injuries

Button batteries (BB) are found in common household items and can lead to significant morbidity and mortality in the pediatric population when ingested. BBs are made of various chemistries and have a unique size and shape that yield significant injury when lodged in the pediatric esophagus. BBs create a local tissue pH environment of 10 to 13 and can induce liquefactive necrosis at the negative pole. This initial injury can progress with further tissue breakdown even after removal. Unfortunately, patients may present with vague symptoms similar to viral illnesses and there is not always a known history of ingestion. Plain film X-ray can be diagnostic. Exposure can lead to caustic injury within 2 hours. Thus, timely endoscopic removal is the mainstay of treatment. Novel mitigation and neutralization strategies have been implemented into treatment guidelines. These include the preremoval ingestion of honey or sucralfate and intraoperative irrigation with acetic acid. Depending on the severity of injury following removal, careful consideration should be given for potential delayed complications including fistulization into major vessels which often leads to death. The National Button Battery Taskforce and several industry members have implemented prevention strategies such as educational safety outreach campaigns, child-resistant packaging changes, and warning labels. Governmental regulation and industry changes are key to limit not only the amount of BB ingestions, but also the devastating consequences that can result. Anonymous reporting of BB injuries through the Global Injury Research Collaborative has been made convenient and centralized through the advent of a user-friendly smartphone iOS/App Store and Android/GooglePlay application called the "GIRC App"; all specialists who manage foreign body cases should contribute their cases to help prevent future injuries. BB ingestion must be recognized and treated promptly using a multidisciplinary approach to optimize outcomes for these patients. Ultimately, a safer BB technology is critically needed to reduce or eliminate the severe and life-threatening injuries in children.

LEVEL OF EVIDENCE

5.

Tracheocutaneous Fistula After Pediatric Open Airway Reconstruction

OBJECTIVES

Tracheocutaneous fistula (TCF) is a common occurrence after pediatric tracheostomy decannulation. However, the persistence of TCF after staged reconstruction of the pediatric airway is not well-described. The primary objective was to determine the rate of persistent TCF after successful decannulation in children with staged open airway reconstruction.

METHODS

A case series with chart review of children who underwent decannulation after double-stage laryngotracheal reconstruction between 2017 and 2019.

RESULTS

A total of 26 children were included. The most common open airway procedure was anterior and posterior costal cartilage grafting (84.6%, 22/26). Median age at decannulation was 3.4 years (IQR: 2.8-4.3) and occurred 7.0 months (IQR: 4.3-10.4) after airway reconstruction. TCF persisted in 84.6% (22/26) of children while 15.4% (4/26) of stomas closed spontaneously. All closures were identified by the one-month follow-up visit. There was no difference in age at tracheostomy (P = .86), age at decannulation (P = .97), duration of tracheostomy (P = .43), or gestational age (P = .23) between stomas that persisted or closed. Median diameter of stent used at reconstruction was larger in TCFs that persisted (7.0 mm vs 6.5 mm, P = .03). Tracheostomy tube diameter (P = .02) and stent size (P < .01) correlated with persistence of TCF on multivariable logistic regression analysis. There were 16 surgical closure procedures, which occurred at a median of 14.4 months (IQR: 11.4-15.4) after decannulation. Techniques included 56.3% (9/16) by primary closure, 18.8% (3/16) by secondary intention and 25% (4/16) by cartilage tracheoplasty. The overall success of closure was 93.8% (15/16) at latest follow-up.

CONCLUSIONS

Persistent TCF occurs in 85% of children who are successfully decannulated after staged open airway reconstruction. Spontaneous closure could be identified by 1 month after decannulation and was more likely when smaller stents and tracheostomy tubes were utilized. Surgeons should counsel families on the frequency of TCF and the potential for additional procedures needed for closure.

Competency-Based Assessment Tool for Pediatric Esophagoscopy: International Modified Delphi Consensus

OBJECTIVES/HYPOTHESIS

Create a competency-based assessment tool for pediatric esophagoscopy with foreign body removal.

STUDY DESIGN

Blinded modified Delphi consensus process.

SETTING

Tertiary care center.

METHODS

A list of 25 potential items was sent via the Research Electronic Data Capture database to 66 expert surgeons who perform pediatric esophagoscopy. In the first round, items were rated as "keep" or "remove" and comments were incorporated. In the second round, experts rated the importance of each item on a seven-point Likert scale. Consensus was determined with a goal of 7 to 25 final items.

RESULTS

The response rate was 38/64 (59.4%) in the first round and returned questionnaires were 100% complete. Experts wanted to "keep" all items and 172 comments were incorporated. Twenty-four task-specific and 7 previously-validated global rating items were distributed in the second round, and the response rate was 53/64 (82.8%) with questionnaires returned 97.5% complete. Of the task-specific items, 9 reached consensus, 7 were near consensus, and 8 did not achieve consensus. For global rating items that were previously validated, 6 reached consensus and 1 was near consensus.

CONCLUSIONS

It is possible to reach consensus about the important steps involved in rigid esophagoscopy with foreign body removal using a modified Delphi consensus technique. These items can now be considered when evaluating trainees during this procedure. This tool may allow trainees to focus on important steps of the procedure and help training programs standardize how trainees are evaluated.

LEVEL OF EVIDENCE

5. Laryngoscope, 131:1168-1174, 2021.

Reinnervation of the Canine Posterior Cricoarytenoid Muscle with Sympathetic Preganglionic Neurons

This experiment investigated the reinnervation of the canine posterior cricoarytenoid (PCA) muscle with preganglionic neurons of the sympathetic nervous system. Six dogs had their right recurrent laryngeal nerve (RLN) sectioned. Four of these dogs had the sympathetic cervical trunk (SCT) implanted into the right PCA muscle, and the two remaining dogs served as denervated controls. Four months later all dogs underwent videolaryngoscopy, electromyography, and electrical stimulation of the SCT. The PCA muscles were excised, sectioned, and stained for glycogen and ATPase. All four experimental PCA muscles demonstrated electrically evoked abduction and tonic electromyographic activity. In two of the specimens, staining (ATPase and PAS) revealed areas of reinnervation with fiber type grouping and glycogen depletion. These results are consistent with the successful reinnervation of the PCA muscle. Further refinement of this technique could be of benefit to patients with bilateral vocal cord paralysis.

Slide tracheoplasty: Predictors of outcomes and literature review

OBJECTIVE

Determine preoperative comorbidities and intraoperative parameters associated with adverse postoperative outcomes.

METHODS

Retrospective case series at a single tertiary care children's hospital from 2010 through 2017.

RESULTS

Twenty-six patients with median age of 6 months and median weight of 7.1 kg underwent slide tracheoplasty. Median time to extubation, length of intensive care unit admission, and length of hospitalization were 7, 27, and 30 days, respectively. Twenty-two (85%) required no additional intervention. Overall success was 87%. One (4%) patient required open revision, and 3 (11%) required tracheostomy. Concomitant cardiac surgery was associated with postoperative tracheostomy (p = 0.04). Age and weight at surgery were inversely correlated with length of intubation (p = 0.03) and length of hospital stay (p = 0.001, p = 0.002) respectively. Hospital stay was 2.2 times longer if preoperative mechanical ventilation was required (p = 0.01) and 39% longer for every 1 mm decrease in airway diameter at the narrowest portion of the stenosis (p = 0.005). There were no deaths related to persistent tracheal stenosis with a median follow-up of 24 months.

CONCLUSION

Slide tracheoplasty is safe and effective. Concomitant cardiac surgery was associated with postoperative tracheostomy. Lower age and weight at surgery were correlated with longer length of intubation and hospital stay. Preoperative mechanical ventilation and smaller airway diameter were associated with longer hospital stay. This information may be helpful in counseling families and planning future prospective studies.

Management and Outcomes of Button Batteries in the Aerodigestive Tract: A Multi-institutional Study

OBJECTIVES/HYPOTHESIS

To describe the clinical presentation, management, and complications associated with button battery impaction in the aerodigestive tract in children.

STUDY DESIGN

Retrospective case series.

METHODS

This multi-institutional study, endorsed by the American Society of Pediatric Otolaryngology research consortium, is a retrospective medical record review, including all children at five tertiary-care institutions presenting with button batteries impacted in the aerodigestive tract between January 2002 and December 2014. Battery type/size, duration and location of impaction, presenting symptoms, treatment, complications, and outcomes were examined.

RESULTS

Eighty-one patients were included (64.2% male), with ingestion witnessed in 20 (24.7%). Median age at presentation was 3 years (range, 1 week-14 years). Median time from diagnosis to removal was 2.5 hours (range, 0.4-72 hours). Locations included the esophagus (n = 48), hypopharynx (n = 1), stomach (n = 6), nasal cavity (n = 22), and ear canal (n = 4). Most common symptoms for esophageal/hypopharyngeal impactions included dysphagia (26.5%), nausea/vomiting (26.5%), drooling (24.5%), cough (18.4%), and fever (18.4%). Most common symptoms for nasal impactions included epistaxis (54.6%), rhinorrhea (40.9%), nasal pain (27.3%), and fever (22.7%). Almost all esophageal impactions were from 3-V (89.5%), 20-mm (81.8%) lithium batteries. Severe esophageal complications included stricture (28.6%), perforation (24.5%), tracheoesophageal fistula formation (8.2%), pneumothorax (4.1%), and bilateral true vocal fold paresis (4.1%). Nasal complications included necrosis (59.1%), septal perforation (27.3%), and saddle nose deformity (4.5%). Duration of impaction correlated with an increased likelihood of persistent symptoms only for nasal batteries (P = .049).

CONCLUSIONS

Button batteries in the upper pediatric aerodigestive tract or ear canal should be considered a surgical emergency, requiring urgent removal and careful vigilance for complications.

LEVEL OF EVIDENCE

4 Laryngoscope, 131:E298-E306, 2021.

pH-neutralizing esophageal irrigations as a novel mitigation strategy for button battery injury

OBJECTIVES/HYPOTHESIS

Ingestion of button batteries (BB) can rapidly lead to caustic esophageal injury in infants and children, resulting in significant morbidity and mortality. To identify novel mitigation strategies, we tested common weakly acidic household beverages, viscous liquids, and Carafate® for their ability to act as protective esophageal irrigations until endoscopic removal of the BB.

STUDY DESIGN

Cadaveric and live animal model.

METHODS

Apple juice, orange juice, Gatorade®, POWERADE®, pure honey, pure maple syrup, and Carafate® were screened using a 3 V lithium (3 V-CR2032) BB on cadaveric porcine esophagus. The most promising in vitro options were tested against a saline control in live American Yorkshire piglets with anode-facing placement of the BB on the posterior wall of the proximal esophagus for 60 minutes. BB voltage and tissue pH were measured before battery placement and after removal. The 10 mL irrigations occurred every 10 minutes from t = 5 minutes. Gross and histologic assessment was performed on the esophagus of piglets euthanized 7 ± 0.5 days following BB exposure.

RESULTS

Honey and Carafate® demonstrated to a significant degree the most protective effects in vitro and in vivo. Both neutralized the tissue pH increase and created more localized and superficial injuries; observed in vivo was a decrease in both full-thickness injury (i.e., shallower depths of necrotic and granulation tissue) and outward extension of injury in the deep muscle beyond surface ulcer margins (P < .05).

CONCLUSIONS

In the crucial period between BB ingestion and endoscopic removal, early and frequent ingestion of honey in the household setting and Carafate® in the clinical setting has the potential to reduce injury severity and improve patient outcomes.

LEVEL OF EVIDENCE

NA Laryngoscope, 129:49-57, 2019.

Basic mechanism of button battery ingestion injuries and novel mitigation strategies after diagnosis and removal

OBJECTIVES/HYPOTHESIS

Button battery (BB) injuries continue to be a significant source of morbidity and mortality, and there is a need to confirm the mechanism of injury for development of additional mitigation strategies.

STUDY DESIGN

Cadaveric piglet esophageal model.

METHODS

Lithium, silver oxide, alkaline, and zinc-air BBs were placed in thawed sections of cadaveric piglet esophagus, bathed in normal saline. Severity of gross visual burn, pH, and temperature were recorded every 30 minutes for 6 hours. In other esophageal tissue specimens, the lithium BB was removed after 24, 36, and 48 hours and the site was irrigated with either 0.25% or 3% acetic acid. Separately, ReaLemon® juice, orange juice, Coke®, Dasani® water, Pepsi®, and saline were infused over a vertically suspended esophagus with a CR2032 lithium battery every 5 minutes for 2 hours while tissue temperature and pH were measured.

RESULTS

A gradual rise in tissue pH and minimal change in temperature was noted for all BBs. ReaLemon® and orange juice applied every 5 minutes were most effective at neutralization of tissue pH with minimal change in tissue temperature. After BB removal (24, 36, 48 hours), irrigation of esophageal tissue specimens with 50-150 mL 0.25% acetic acid neutralized the highly alkaline tissue pH.

CONCLUSIONS

BB appear to cause an isothermic hydrolysis reaction resulting in an alkaline caustic injury. Potential new mitigation strategies include application of neutralizing weakly acidic solutions that may reduce esophageal injury progression.

LEVEL OF EVIDENCE

NA Laryngoscope, 127:1276-1282, 2017.

Flexible Bronchoscopic Removal of a Distal Bronchial Foreign Body with Cinefluoroscopic Guidance

A 15-year-old girl presented to the emergency department with cough and bloody sputum. A chest radiograph demonstrated a radiopaque foreign body (a tongue stud) in the right lower lobe. Rigid and flexible bronchoscopy failed to localize the foreign body. Under fluoroscopic guidance, the foreign body was identified in a right lower lobe distal bronchus; it could be visualized from a distance with a 3.5-mm flexible bronchoscope. An endobronchial biopsy forceps was passed through the suction port of the bronchoscope, but the view of the foreign body was obstructed by the biopsy forceps. The bronchoscope could not be advanced closer to the foreign body, because its diameter was greater than that of the bronchus. Under cinefluoroscopic guidance, the endobronchial biopsy forceps was then used to remove the foreign body. A chest radiograph obtained after removal was normal. The patient was discharged home the following day. Removal of distal bronchial foreign bodies can be challenging, because the bronchial diameter may preclude the advancement of the bronchoscope. Cinefluoroscopy is a relatively safe therapeutic adjunct that may avert the need for thoracotomy.

Rare Upper Airway Anomalies

A broad spectrum of congenital upper airway anomalies can occur as a result of errors during embryologic development. In this review, we will describe the clinical presentation, diagnosis, and management strategies for a few select, rare congenital malformations of this system. The diagnostic tools used in workup of these disorders range from prenatal tests to radiological imaging, swallowing evaluations, indirect or direct laryngoscopy, and rigid bronchoscopy. While these congenital defects can occur in isolation, they are often associated with disorders of other organ systems or may present as part of a syndrome. Therefore workup and treatment planning for patients with these disorders often involves a team of multiple specialists, including paediatricians, otolaryngologists, pulmonologists, speech pathologists, gastroenterologists, and geneticists.

Pediatric laryngotracheal reconstruction with tissue-engineered cartilage in a rabbit model

OBJECTIVES/HYPOTHESIS

To develop an effective rabbit model of in vitro- and in vivo-derived tissue-engineered cartilage for laryngotracheal reconstruction (LTR).

STUDY DESIGN

1) Determination of the optimal scaffold 1% hyaluronic acid (HA), 2% HA, and polyglycolic acid (PGA) and in vitro culture time course using a pilot study of 4 by 4-mm in vitro-derived constructs analyzed on a static culture versus zero-gravity bioreactor for 4, 8, and 12 weeks, with determination of compressive modulus and histology as outcome measures. 2) Three-stage survival rabbit experiment utilizing autologous auricular chondrocytes seeded in scaffolds, either 1% HA or PGA. The constructs were cultured for the determined in vitro time period and then cultured in vivo for 12 weeks. Fifteen LTRs were performed using HA cartilage constructs, and one was performed with a PGA construct. All remaining specimens and the final reconstructed larynx underwent mechanical testing, histology, and glycosaminoglycan (GAG) content determination, and then were compared to cricoid control specimens (n = 13) and control LTR using autologous thyroid cartilage (n = 18).

METHODS

1) One rabbit underwent an auricular punch biopsy, and its chondrocytes were isolated and expanded and then encapsulated in eight 4 by 4-mm discs of 1% HA, 2% HA, PGA either in rotary bioreactor or static culture for 4, 8, and 12 weeks, respectively, with determination of compressive modulus, GAG content, and histology. 2) Sixteen rabbits underwent ear punch biopsy; chondrocytes were isolated and expanded. The cells were seeded in 13 by 5 by 2.25-mm UV photopolymerized 1% HA (w/w) or calcium alginate encapsulated synthetic PGA (13 × 5 × 2 mm); the constructs were then incubated in vitro for 12 weeks (the optimal time period determined above in paragraph 1) on a shaker. One HA and one PGA construct from each animal was tested mechanically and histologically, and the remaining eight (4 HA and 4 PGA) were implanted in the neck. After 12 weeks in vivo, the most optimal-appearing HA construct was used as a graft for LTR in 15 rabbits and PGA in one rabbit. The seven remaining specimens underwent hematoxylin and eosin, Safranin O, GAG content determination, and flexural modulus testing. At 12 weeks postoperative, the animals were euthanized and underwent endoscopy. The larynges underwent mechanical and histological testing. All animals that died underwent postmortem examination, including gross and microhistological analysis of the reconstructed airway.

RESULTS

Thirteen of the 15 rabbits that underwent LTR with HA in vitro- and in vivo-derived tissue-engineered cartilage constructs survived. The 1% HA specimens had the highest modulus and GAG after 12 weeks in vitro. The HA constructs became well integrated in the airway, supported respiration for the 12 weeks, and were histologically and mechanically similar to autologous cartilage.

CONCLUSIONS

The engineering of in vitro- and in vivo-derived cartilage with HA is a novel approach for laryngotracheal reconstruction. The data suggests that the in vitro- and in vivo-derived tissue-engineered approaches may offer a promising alternative to current strategies used in pediatric airway reconstruction, as well as other head and neck applications.

LEVEL OF EVIDENCE

NA. Laryngoscope, 126:S5-S21, 2016.

SSAC Spotlight Series: Button Battery Injuries: 2014 Task Force Update

Program Description:

More than 3500 battery ingestions occur each year in the United States. Over the past 8 years, the number of moderate to severe injuries has increased, including fatalities. A multidisciplinary national button battery task force was set up in 2012 under the American Broncho-Esophagological Association and the American Academy of Pediatrics with the overall mission of reducing button battery injuries in children. This miniseminar aims to outline the current status of the problem, insights into clinical management algorithms, industry involvement, product safety standards, and educational outreach activities. All task force activities will be discussed.

Educational Objectives:

(1) Discuss the incidence of button battery ingestions, mechanisms of injury, clinical presentation, and common household sources of button batteries. (2) Implement treatment algorithms and be able to recognize immediate and delayed complications. (3) Implement solutions with industry collaboration and educational outreach efforts to prevent future button battery injuries.

Pediatric button battery injuries: 2013 task force update

Over the last 10 years, there has been a dramatic rise in the incidence of severe injuries involving children who ingest button batteries. Injury can occur rapidly and children can be asymptomatic or demonstrate non-specific symptoms until catastrophic injuries develop over a period of hours or days. Smaller size ingested button batteries will often pass without clinical sequellae; however, batteries 20mm and larger can more easily lodge in the esophagus causing significant damage. In some cases, the battery can erode into the aorta resulting in massive hemorrhage and death. To mitigate against the continued rise in life-threatening injuries, a national Button Battery Task Force was assembled to pursue a multi-faceted approach to injury prevention. This task force includes representatives from medicine, public health, industry, poison control, and government. A recent expert panel discussion at the 2013 American Broncho-Esophagological Association (ABEA) Meeting provided an update on the activities of the task force and is highlighted in this paper.

Clinical consensus statement: tracheostomy care

OBJECTIVE

This clinical consensus statement (CCS) aims to improve care for pediatric and adult patients with a tracheostomy tube. Approaches to tracheostomy care are currently inconsistent among clinicians and between different institutions. The goal is to reduce variations in practice when managing patients with a tracheostomy to minimize complications.

METHODS

A formal literature search was conducted to identify evidence gaps and refine the scope of this consensus statement. The modified Delphi method was used to refine expert opinion and facilitate a consensus position. Panel members were asked to complete 2 scale-based surveys addressing different aspects of pediatric and adult tracheostomy care. Each survey was followed by a conference call during which results were presented and statements discussed.

RESULTS

The panel achieved consensus on 77 statements; another 39 were dropped because of lack of consensus. Consensus was reached on statements that address initial tracheostomy tube change, management of emergencies and complications, prerequisites for decannulation, management of tube cuffs and communication devices, and specific patient and caregiver education needs.

CONCLUSION

The consensus panel agreed on statements that address the continuum of care, from initial tube management to complications in children and adults with a tracheostomy. The panel also highlighted areas where consensus could not be reached and where more research is needed. This consensus statement should be used by physicians, nurses, and other stakeholders caring for patients with a tracheostomy.

Laryngotracheal reconstruction with posterior costal cartilage grafts: Outcomes at a single institution

Objective: To describe our outcomes after laryngotracheal reconstruction that required posterior costal cartilage grafting focused on decannulation rates and complications.

Study Design: Case series with chart review.

Subjects and Methods: Charts were reviewed on 58 patients. Operation specific and overall decannulation rates were determined. Complications were reviewed and correlated with technique of graft placement. Available voice outcomes were reviewed.

Results: Forty-eight patients were included. There was no statistically significant correlation between degree of stenosis and rate of decannulation. The overall decannulation rate, regardless of number of surgeries performed, was 96 percent. The relative risk for complications was higher among children who had a sutured versus a sutureless flanged posterior graft (RR = 2.5, P < 0.01). The most common voice anomaly was supraglottic compression.

Conclusions: Operation-specific decannulation rates are not significantly different with increasing disease severity, although the power to detect small differences in this study is low. Sutureless graft placement is associated with a lower complication rate. Supraglottic compression is a common postoperative compensatory vocal behavior and may correlate with disease severity.

Postoperative Recovery After Microdebrider Intracapsular or Monopolar Electrocautery Tonsillectomy

OBJECTIVE

To prospectively assess the postoperative recovery in patients randomly selected to receive either microdebrider intracapsular tonsillectomy (MT) or monopolar electrocautery tonsillectomy (ET).

DESIGN

A prospective, randomized, single-blinded study.

SETTING

Tertiary care children's hospital.

PATIENTS

A total of 74 patients between the ages of 3 and 7 years undergoing adenotonsillectomy for obstruction were randomly assigned to the MT and ET groups.

MAIN OUTCOME MEASURES

Families were blinded to the technique used and given a checklist to fill out daily quantifying pain, activity, diet, and the number of doses of pain medication given over a 10-day period. Other variables assessed included the time of surgery and intraoperative blood loss.

RESULTS

The average time of surgery was 16.9 minutes for ET compared with 20.9 minutes for MT (P<.001). The average blood loss was 30 mL for ET compared with 45 mL for MT (P = .01). Resumption of near-normal dietary intake was achieved 1.7 days earlier in patients receiving MT compared with ET (P = .04). There was no significant difference in the number of days taken for the resolution of pain or resumption of normal activity between the 2 groups.

CONCLUSIONS

Microdebrider tonsillectomy takes over 4 minutes longer to perform compared with ET and has slightly higher intraoperative blood loss. There appears to be a slight advantage in the resumption of normal dietary intake with MT but no significant difference in the number of days taken for the resolution of pain or resumption of normal activity.

Tracheal anomalies in Pfeiffer syndrome

OBJECTIVE

To determine the types and frequency of airway anomalies in patients with Pfeiffer syndrome.

DESIGN

Retrospective case series.

SETTING

Academic tertiary care pediatric hospital.

PARTICIPANTS

Eleven patients with Pfeiffer syndrome, 6 of whom were severely affected, were identified. All were included in the study.

MAIN OUTCOME MEASURES

Presence of tracheal anomalies, need for tracheotomy, and length of life.

RESULTS

The 6 severely affected patients had mutations in genes that code for fibroblast growth factor receptor 2 (S351C [3 patients]; C342S [2 patients]; and W290C [1 patient]). Five of these patients were diagnosed during bronchoscopy or tracheotomy as having a congenital tracheal cartilaginous sleeve. In 1 patient, supportive care was withdrawn at 2 weeks of life, and the patient died. The remaining 5 patients required tracheotomy because of severe upper airway obstruction. Three of these patients died (at ages 9 months and 7 and 15 years). Two are still alive at ages 23 and 18 months.

CONCLUSIONS

Patients with Pfeiffer syndrome manifest significant airway pathologic conditions. Upper airway obstruction is related to midface hypoplasia and secondary nasal obstruction. Tracheal anomalies have been infrequently reported.

Pistachio nutshell foreign body of the oral cavity in two children

Pistachio nutshell foreign bodies have been documented in the literature, occurring most commonly in the bronchi. The objective of this study is to report on two cases of oral cavity lesions, which were subsequently found to be pistachio nutshell foreign bodies. The first patient is a 9-month-old male who presented with a hard palate mass measuring 1.5 cm. The patient was evaluated in the operating room, and found to have a submucosal pistachio nutshell foreign body. The second patient is a 17-month-old female who presented with a firm, fixed midline hard palate mass. The lesion was subsequently noted to dislodge from the palate, and was identified as a pistachio nutshell.

Otolaryngologic manifestations of the 22q11.2 deletion syndrome

BACKGROUND

The 22q11.2 chromosome deletion syndrome occurs at a frequency of 1 in 4000 live births. Fluorescent in situ hybridization is a reliable means of testing for this genetic abnormality.

OBJECTIVE

To describe the otolaryngologic manifestations of the 22q11.2 deletion syndrome to improve recognition and management of these disorders.

PATIENTS AND DESIGN

A retrospective medical record review of 102 patients with chromosome 22q 11.2 deletions confirmed by fluorescent in situ hybridization.

SETTING

A multidisciplinary 22q11.2 deletion clinic at an academic children's hospital.

OUTCOME MEASURE

All otolaryngologic problems were recorded, including facial dysmorphic features, velopharyngeal insufficiency, speech and airway abnormalities, feeding difficulties, gastroesophageal reflux, hearing loss, otitis media, sinus problems, and vascular anomalies. Additionally, available objective test results were recorded, including those from audiograms, imaging studies, endoscopies, speech evaluations, and vascular studies.

RESULTS

Dysmorphic facial features were found in most patients. Velopharyngeal incompetence was noted in 76 patients, while overt submucosal clefts were found in 11 patients. Most patients had speech and language delays. In addition, 53 patients had chronic or recurrent otitis media, and 28 had recurrent sinorhinitis. Furthermore, feeding problems were found in 48 patients, while vascular anomalies of the head and neck were found in 16 patients.

CONCLUSION

Otolaryngologic abnormalities are relatively common and important to recognize with the 22q11.2 deletion syndrome.

Laryngeal electromyography in the management of vocal cord mobility problems in children

OBJECTIVES

To evaluate the efficacy and clinical usefulness of laryngeal electromyography (EMG) in the evaluation and management of vocal cord mobility problems in children; and to determine the ability of laryngeal EMG to differentiate vocal fold fixation versus paralysis.

STUDY DESIGN

Case-series review of 8 children with vocal cord immobility who underwent laryngeal EMG.

METHODS

Eight children with bilateral vocal fold immobility underwent microlaryngoscopy and electromyography. Bipolar concentric needle electrodes were used and implanted separately into both posterior cricoarytenoid (PCA) and both thyroarytenoid (TA) muscles. EMG activity was recorded during spontaneous ventilation under a light plane of anesthesia with propofol. EMG activity was correlated with the phases of the respiratory cycle.

RESULTS

Three patients had evidence of normal EMG activity with PCA activity peaking during early inspiration. Maximal TA activity occurred expiration. These patients were assumed to have vocal fold fixation. Two of these 3 patients underwent laryngotracheoplasty (LTP) with posterior glottic expansion with costal cartilage. One is being considered for LTP in the future. Five patients had abnormal EMG activity and remain tracheotomy-dependent. Four patients exhibited synkinetic activity with peak PCA activity during expiration and peak TA activity during expiration. Two patients had both fixation and unilateral vocal cord paralysis. One was successfully decannulated after posterior graft LTP and the other is planned for the future.

CONCLUSIONS

Electromyography, which differentiates paralysis from fixation, is a useful diagnostic tool in the evaluation of children with vocal cord immobility.

Adenovirus-mediated ex vivo gene transfer of human vascular endothelial growth factor in a rabbit laryngotracheal reconstruction model

Free autologous cartilage, which is used in laryngotracheal reconstruction (LTR), may undergo progressive necrosis as a result of delayed revascularization. Angiogenic growth factors, such as vascular endothelial growth factor (VEGF), promote angiogenesis in the ischemic environment. We studied the effect of ex vivo gene transfer of VEGF121 on cartilage angiogenesis and graft survival in a rabbit model of LTR. Sixty rabbits underwent LTR with auricular cartilage. The grafts were treated at 1 x 10(9) plaque-forming units with 1) VEGF121 (n = 20), 2) LacZ reporter gene (n = 20), or 3) saline solution (n = 20). Graft neovascularization and survival were histologically assayed at 1 and 10 weeks. Angiogenesis was enhanced at both 1 and 10 weeks after treatment with VEGF121 as compared to controls (p < .001). No statistical improvement in graft survival was evident after treatment with VEGF121. Ex vivo gene transfer to cartilage may be a promising gene therapy strategy to enhance revascularization--and, potentially, cartilage survival--under the proper conditions.

The temporal course of adenovirus-mediated gene transfer in the rat larynx

OBJECTIVE

Polypeptide growth factors have important influences on wound-healing and scar tissue formation. Specific growth factors or their inhibitors may potentially decrease scar tissue formation and prevent subglottic stenosis. Gene transfer using recombinant adenovirus may be an ideal method to mediate endogenous production of growth factors to inhibit fibrosis.

STUDY DESIGN

The study incorporated adenovirus-mediated transduction of normal and stenotic rat larynges and histologic analysis of the sequential expression of a beta-galactosidase marker gene over time.

SETTING

The study was conducted at the animal care facility of an academic children's hospital.

RESULTS

We report successful transduction in normal and injured rat larynx with peak expression of beta-galactosidase at 2 days after transduction and almost complete disappearance by 7 days. There appeared to be an early inflammatory response to the viral injection, but at 7 and 14 days after injection (transduction) the uninjured rat larynges resumed a normal histologic appearance. All distant sites stained negative for beta-galactosidase.

CONCLUSION

Recombinant adenovirus-mediated gene transfer is feasible in the rat larynx with transient duration and limited toxicity.

SIGNIFICANCE

Adenovirus-mediated gene transfer has the potential to deliver growth factors that modulate wound healing and inflammation in the larynx by inhibiting fibrosis.

Airway complications of infant botulism: ten-year experience with 60 cases

OBJECTIVE

The study goal was to understand the incidence, etiology, and management of airway complications in infant botulism.

METHODS

We conducted a retrospective review of the period from January 1, 1987, to December 31, 1997.

SETTING

Urban tertiary care children's hospital.

RESULTS

Of 60 children with infant botulism, 37 (61.7%) required endotracheal intubation for a mean of 21 days. No patient required a tracheostomy. Airway complications (stridor, subglottic stenosis, granuloma formation) occurred in 5 (13.5%) of 37 patients, with 3 requiring surgical bronchoscopy. Of the 37 children, 14 (37.8%), including 4 with airway complications, had endotracheal tube leak pressures recorded. In 3 (50%) of 6 patients with measured leak pressures of greater than 40 cm H2O, airway complications developed. Complications did not develop in patients with leak pressures of less than 20 cm H2O. No correlation between length of intubation and complications could be established.

CONCLUSION

Airway complications in infant botulism may be accompanied by high leak pressures and can be managed with endoscopic techniques. The study data suggest that leak pressures should be measured on a regular basis and maintained at less than 20 to 25 cm H2O. A prospective trial to study this issue is warranted. Tracheotomy is not routinely necessary. A high index of suspicion, early diagnosis, and prompt intervention are required for the optimal management of airway complications in infant botulism.

Use of helium-oxygen mixtures to relieve upper airway obstruction in a pediatric population

OBJECTIVES

Helium as a component of inspired gas decreases turbulent flow and airway resistance. Helium-oxygen mixtures have been used since the 1930s in the management of patients with upper airway obstruction. The objective of this study was to evaluate the efficacy of helium-oxygen mixtures in relieving upper airway obstruction in a pediatric population.

STUDY DESIGN

Retrospective chart review of 42 pediatric patients who received helium-oxygen mixtures for upper airway obstruction within a 3-year period.

METHODS

The study protocol included 42 pediatric patients, aged 1 week to 14 years, who were admitted to the Children's Hospital of Philadelphia from June 1997 to December 2000 and who received a total of 44 treatments of helium-oxygen therapy for upper airway obstruction. Response to treatment was determined by reduction in work of breathing noted on the chart.

RESULTS

Thirty-two of 44 helium-oxygen treatments resulted in a positive response (73%). There were no significant differences in demographic characteristics between responders and nonresponders, except all of the premature infants were responders and 6 of the 9 patients with syndromes were nonresponders.

CONCLUSIONS

Helium-oxygen therapy is a useful adjunct therapy for upper airway obstruction. Controlled clinical trials are necessary to better define the appropriate settings for use of helium-oxygen.

Transforming growth factor and neutralizing antibodies in subglottic stenosis

Transforming growth factor beta 1 (TGF-beta1), which is implicated in the pathogenesis of fibrotic diseases such as interstitial fibrosis, may be associated with subglottic stenosis. To study this hypothesis, we measured TGF-beta1 expression sequentially in 28 rats after posterior cricoid injury, using both standard immunohistochemistry and reverse transcriptase-polymerase chain reaction. In addition, an osmotic pump infused TGF-beta1 in 18 rats, normal saline solution in 9 rats, and neutralizing antibodies in 9 rats. Specimens were stained for fibronectin and procollagen at 1, 7, and 21 days and underwent optical density analysis. In the injured airway, TGF-beta1 expression peaked at 1 day and returned to baseline by 21 days. The TGF-beta1 infusion led to an increase in the expression of extracellular matrix proteins relative to controls. In contrast, neutralizing antibodies led to a decrease in extracellular matrix protein expression. These findings suggest that TGF-beta1 may possibly play a role in the pathogenesis of subglottic stenosis.

Use of intranasal fentanyl in children undergoing myringotomy and tube placement during halothane and sevoflurane anesthesia

BACKGROUND

Many children are restless, disoriented, and inconsolable immediately after bilateral myringotomy and tympanosotomy tube placement (BMT). Rapid emergence from sevoflurane anesthesia and postoperative pain may increase emergence agitation. The authors first determined serum fentanyl concentrations in a two-phase study of intranasal fentanyl. The second phase was a prospective, placebo-controlled, double-blind study to determine the efficacy of intranasal fentanyl in reducing emergence agitation after sevoflurane or halothane anesthesia.

METHODS

In phase 1, 26 children with American Society of Anesthesiologists (ASA) physical status I or II who were scheduled for BMT received intranasal fentanyl, 2 microg/kg, during a standardized anesthetic. Serum fentanyl concentrations in blood samples drawn at emergence and at postanesthesia care unit (PACU) discharge were determined by radioimmunoassay. In phase 2, 265 children with ASA physical status I or II were randomized to receive sevoflurane or halothane anesthesia along with either intranasal fentanyl (2 microg/kg) or saline. Postoperative agitation, Children's Hospital of Eastern Ontario Pain Scale (CHEOPS) scores, and satisfaction of PACU nurses and parents with the anesthetic technique were evaluated.

RESULTS

In phase 1, the mean fentanyl concentrations at 10 +/- 4 min (mean +/- SD) and 34 +/- 9 min after administering intranasal fentanyl were 0.80 +/- 0.28 and 0.64 +/- 0.25 ng/ml, respectively. In phase 2, the incidence of severe agitation, highest CHEOPS scores, and heart rate in the PACU were decreased with intranasal fentanyl. There were no differences between sevoflurane and halothane in these measures and in times to hospital discharge. The incidence of postoperative vomiting, hypoxemia, and slow respiratory rates were not increased with fentanyl.

CONCLUSIONS

Serum fentanyl concentrations after intranasal administration exceed the minimum effective steady state concentration for analgesia in adults. The use of intranasal fentanyl during halothane or sevoflurane anesthesia for BMT is associated with diminished postoperative agitation without an increase in vomiting, hypoxemia, or discharge times.

Incidence and prevalence of recurrent respiratory papillomatosis among children in Atlanta and Seattle

The incidence and prevalence of recurrent respiratory papillomatosis (RRP) for children aged <18 years were estimated in 2 US cities, Atlanta and Seattle, in 1996. All otolaryngologists in a 24-county area in metropolitan Atlanta (101 physicians) and an 8-county area in metropolitan Seattle (139 physicians) agreed to participate in the study. Medical record chart abstraction was performed only for children with documented current residence in the study area (21 patients in Atlanta and 14 patients in Seattle). The incidence rate for juvenile RRP was 1.11/100,000 population in Atlanta and 0.36/100, 000 in Seattle. The prevalence rate was 2.59/100,000 population in Atlanta and 1.69/100,000 in Seattle. In neither city did prevalences differ significantly when stratified by sex or race. Extrapolation of these estimates to the US population suggests that 80-1500 incident cases and 700-3000 prevalent cases of juvenile RRP will occur in the United States during 1999.

Pediatric angioedema: ten years' experience

OBJECTIVE

To clarify the cause, clinical course, and management of children with angioedema.

DESIGN

Retrospective review.

SETTING

Urban tertiary care hospital for children.

PATIENTS

Consecutive sample of all children hospitalized from January 1, 1987, to December 31, 1997, with the diagnosis of angioedema. Complete records permitting analysis were available for 10 patients.

MAIN OUTCOME MEASURES

Sex, age, site, symptoms at initial examination, cause, therapeutic management, and clinical outcome.

RESULTS

Seven boys and 3 girls, a mean age of 7.7 years, had angioedema of the head or neck, most often facial (8/10 [80%]). Manifesting symptoms, in addition to swelling, were tenderness or pain in 4 children (40%), dyspnea in 3 (30%), dysphagia (including drooling and spitting) in 3 (30%), and hoarseness in 1 (10%). Angioedema was due to food in 4 children (40%), insect bites in 3 (30%), infection in 2 (20%), and an antibiotic in 1 (10%). Treatment was pharmacological in all cases. No child required intubation or tracheotomy. Care in the intensive care unit was necessary for 1 child (10%).

CONCLUSIONS

Pediatric angioedema exhibits a different cause and clinical manifestations than does adult angioedema. Prompt diagnosis and early treatment with an intravenous corticosteroid, an antihistamine, and/or epinephrine lead to rapid resolution and may, in appropriately staffed settings, avoid the need for care in the intensive care unit or airway intervention. Management algorithms based on adult experience must be modified to account for the milder pediatric manifestations of this immunologic disease.