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Paediatric subglottic stenosis – Have things changed? Our experience from a developing tertiary referral centre
International Journal of Pediatric Otorhinolaryngology 79 (2015) 2020–2022
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Paediatric subglottic stenosis – Have things changed? Our experience from a developing tertiary referral centre Rishi Talwar *, Jagdeep Singh Virk, Yogesh Bajaj ENT Department, Barts Children’s and the Royal London Hospital, United Kingdom
A R T I C L E I N F O
A B S T R A C T
Article history: Received 31 March 2015 Received in revised form 20 August 2015 Accepted 21 August 2015 Available online 8 September 2015
Background: Paediatric airway disorders are common, particularly in the context of improved ventilation methods for neonates in intensive care units. Management is not standardised. Objectives: To assess the number, severity, management and outcomes of all patients diagnosed with subglottic stenosis at a developing tertiary referral centre. Study design: 19 month prospective longitudinal study. Study population: All patients who underwent microlaryngobronchoscopy (MLB) were included. Subglottic stenosis (SGS) was graded intraoperatively using the Myer–Cotton classification. Results: 102 patients underwent MLB during this period. 33 of 102 patients (32.4%) were diagnosed with SGS +/ other co-pathologies. Mean and median age at diagnostic procedure were 24.7 months (SD 23.5) and 18 months, respectively. At their first MLB, 22 of 33 patients (66.7%) were found to have a Grade 1 SGS, 7 of 33 (21.2%) were Grade 2 and the remaining 4 of 33 (12.1%) were Grade 3. We had no patients with Grade 4 SGS. During this period, these patients with SGS underwent 73 MLBs +/ interventions (2.21 per patient) such as incision and balloon dilatation, tracheostomy (2 of 33) or ultimately, laryngotracheal reconstruction (LTR) (2 of 33). A further 3 patients have since undergone LTR. No significant unexpected events occurred. Conclusions: These findings suggest that subglottic stenosis may be evolving in terms of its presentation and management. Management can more often be endoscopic and perhaps avoid tracheostomy or laryngotracheal reconstruction. Further long term prospective studies are required. ß 2015 Published by Elsevier Ireland Ltd.
Keywords: Subglottic stenosis Endoscope Laryngotracheal reconstruction Stridor Paediatric
1. Introduction
2. Materials and methods
Paediatric airway disorders are common, particularly in the context of improved ventilation methods for neonates in intensive care units. Subglottic stenosis (SGS) can be congenital or acquired, with the latter having a higher incidence, reported to be in the range of 1–8% after intubation [1]. Management is not standardised but endoscopic techniques are increasingly employed in the form of balloon laryngoplasty/dilatation [2–8]. Management must be tailored for each individual patient’s circumstances. The aim of this study was to assess the number, severity, management and outcomes of all patients diagnosed with subglottic stenosis by one team in our newly developing paediatric airway service at Barts Children’s and the Royal London Hospitals. This was in keeping with the current NICE guidelines on auditing airway and specifically balloon dilatation procedures [9].
Data was prospectively collected from March 2012 to November 2013. All patients who underwent microlaryngobronchoscopy (MLB) by the senior author and his team were included.
* Corresponding author at: ENT Department, Barts Children’s and Royal London Hospital, Whitechapel Road, Whitechapel, London E1 1BB, United Kingdom. Tel.: +44 0790 896 0034; fax: +44 0203 845 2964. E-mail address: [email protected] (R. Talwar). http://dx.doi.org/10.1016/j.ijporl.2015.08.031 0165-5876/ß 2015 Published by Elsevier Ireland Ltd.
2.1. Ethical considerations Ethical approval was not required by the hospital committee as the data was prospectively collated and standard management was not deviated from for these patients. 2.2. Surgical technique and peri-operative care All patients underwent our standard departmental anaesthetic induction with spontaneous ventilation. During each MLB, subglottic stenosis was graded intraoperatively using the Myer– Cotton classification to indicate the severity of the pathology, based on the size of an endotracheal tube fitting with a leak at 20 cm H2O. Suspension with a baby Benjamin laryngoscope was performed as required. Radial incisions were made (2–3) with a
R. Talwar et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 2020–2022
2021
sickle knife. Balloon dilatation was carried out dependent upon patient tolerance, i.e. how quickly the patient desaturated. Usually 2 dilatations for 45 s each were performed. The size of the balloon used was determined by the expected tracheal diameter based on the patient’s corrected age. Intraoperatively, all children, received one dose of steroid (dexamethasone). Post-operatively, all patients had regular observations, particularly their oxygen saturations and respiratory rate but were also monitored for any stridor. Anti-reflux medication was not routinely prescribed unless significant signs of reflux were found during the MLB or following combined laryngeal cleft repairs or laryngotracheal reconstruction. 3. Results 3.1. Microlaryngobronchoscopy (MLB) data 102 patients underwent MLB during this period. 33 of 102 patients (32.4%) were diagnosed with SGS +/ other co-pathologies. The vast majority of the other 69 patients had other pathologies, such as laryngomalacia, laryngeal cleft, haemangioma and vocal cord palsy. The commonest presenting complaints were recurrent croup and stridor. Indications for MLB included choking episodes, recurrent chest infections/croup, failure to thrive, noisy breathing and swallowing problems (following video fluoroscopy). All patients were initially assessed in the outpatient clinic or ward and underwent preoperative awake flexible nasolaryngoscopy assessment, as tolerated. Mean and median age at diagnostic procedure were 24.7 months (SD 23.5) and 18 months respectively. Mean follow up was 12 months. 3.2. Myer–Cotton grading At their first MLB, 22 of 33 patients (66.7%) were found to have a Grade 1 SGS, 7 of 33 (21.2%) were Grade 2 and the remaining 4 (12.1%) were Grade 3. We had no patients with a Grade 4 SGS (Figs. 1 and 2). All patients were symptomatic. Of note, 3 patients had no history of trauma or intubation and were presumed to be of congential origin.
Fig. 1. Distribution of subglottic stenosis according to the Myer–Cotton grading system.
3.3. Management During this period, these patients with SGS underwent 73 MLBs +/ interventions (2.21 per patient) such as incision and balloon dilatation, tracheostomy (2 of 33) or ultimately, laryngotracheal reconstruction (LTR) (2 of 33). A further 3 patients have since undergone LTR. Repeat dilatations were typically performed every 3 months (range 6 weeks to 6 months). Treatment was based upon the severity of symptoms and significance of the stenosis. Management was therefore on an individualised basis within a paradigm of endoscopic dilatations. With two of the grade 3 SGS patients, it became clinically apparent earlier, that they were not responding well to endoscopic management, both by measurement at MLB but also, more importantly, based upon the patients’ symptoms. Endoscopic management in these cases was therefore abandoned sooner, for
Fig. 2. Myer–Cotton grading of subglottic stenosis with endoscopic balloon dilatation. (A) Normal larynx, (B) Grade 1 SGS, (C) Grade 2 SGS, (D) Grade 3 SGS, (E) Balloon laryngoplasty.
R. Talwar et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 2020–2022
2022
Table 1 Outcomes related to grade of subglottic stenosis. Myer–Cotton grade
Number of patients
Total number of MLB + intervention/dilatation (per patient)
Tracheostomy required (%)
LTR required (%)
1 2 3 4
22 7 4 0
44 (2.00) 20 (2.86) 9 (2.25) N/A
0 0 2a (50%) N/A
0 0 2 (50%) N/A
33
73 (2.21)
2 (6%)
2 (6%)
Overall a
Both ultimately required LTR.
the relatively safer option of a tracheostomy and ultimately LTR (Table 1). 3.4. Complications We had no deaths and no significant unexpected events in these patients. 4. Discussion 4.1. Synopsis of key findings Approximately one-third (32.4%) of the patients presenting to our paediatric airway department who required a MLB were found to have SGS. Of these, approximately 1 in 6 will require definitive management with a LTR, sometimes requiring a tracheostomy to stabilise the patient and enable them to grow pre-LTR. The remainder were managed endoscopically, either with monitoring +/ medications or repeated balloon dilatations (Fig. 2). This appears to be a significantly higher rate of SGS as compared to the 21% presented by Bailey et al. in 2006, based on data collected at Great Ormond Street Hospital over 5 years [10]. We propose that this higher than expected rate may be due to a number of reasons. These include increased survival of pre-term neonates with congenital abnormalities and acquired SGS secondary to intubation, alongside improved diagnostic rates with increasing safety and thus use of MLB. In our series, there were a few likely congenital SGS, given that these patients had no history of trauma or intubation. These were managed in the same manner but given our sample size, no conclusions can be drawn based on statistical significance between these 2 sub-groups, of presumed congenital versus acquired SGS. We further suggest that while the more severe grades of SGS previously had to be managed definitively by tracheostomy or LTR, it now appears that an increasing proportion of these can be managed effectively using endoscopic methods. A number of recent studies confirm that balloon laryngoplasty may be considered the first line treatment for subglottic stenosis, particularly for the acquired subtype [3,6]. A systematic review concluded that balloon dilatation for subglottic stenosis was a highly effective, low risk alternative or adjunct to traditional reconstructive procedures [7]. The caveat remains the severe SGS subgroup, in that these patients have an increased risk of treatment failure with balloon laryngoplasty alone with suggestions that, in some cases, failed balloon dilatation cases may lead to detrimental effects including an increased risk of unplanned urgent interventions as compared with LTR [4,5]. This was indeed borne out in our series, in which all grade 3 SGS, ultimately required a laryngotracheal reconstruction, which remains an important, relatively safe and viable option for these patients [2,8]. In addition, experientially, acute forms of SGS appeared to respond better than chronic SGS patients. However, further data are required to elucidate this further as very few patients with a truly acute subglottic injury were treated in our series.
4.2. Limitations This study reflects the needs of our population and may not be generalisable. We recommend further prospective studies to collate data from all paediatric centres. The national paediatric airway registry is currently being set up and will be invaluable in this regard. We should also note the role of selection bias as only children selected for MLB are included in this series. As a corollary to this, awake flexible nasolaryngoscopy can help identify glottic and supraglottic pathology. However, we believe that, although useful, awake assessment cannot reliably evaluate the subglottis for copathologies. 5. Conclusion We present our experience at a developing single specialist centre and our findings suggest that subglottic stenosis may be evolving in terms of its presentation and management. These findings are also suggested based on UK hospital episode statistical data from 2004 to 2014. Management can more often be endoscopic and hence avoid tracheostomy or laryngotracheal reconstruction. Further long term prospective studies are required to confirm the reproducibility of these successful outcomes. Conflict of interest None. Financial disclosures None. References [1] M.S. Morrissey, C.M. Bailey, Diagnosis and management of subglottic stenosis after neonatal ventilation, Arch. Dis. Child. 65 (10) (1990) 1103–1104. [2] Y. Bajaj, L.A. Cochrane, C.G. Jephson, M.E. Wyatt, C.M. Bailey, D.M. Albert, et al., Laryngotracheal reconstruction and cricotracheal resection in children: recent experience at Great Ormond Street Hospital, Int. J. Pediatr. Otorhinolaryngol. 76 (4) (2012) 507–511. [3] A. Filiz, S.O. Ulualp, Long-term outcomes of balloon dilation for acquired subglottic stenosis in children, Case Rep. Otolaryngol. 2014 (2014) 304593. [4] M. Lang, S.E. Brietzke, A systematic review and meta-analysis of endoscopic balloon dilation of pediatric subglottic stenosis, Otolaryngol. Head Neck Surg. 150 (2) (2014) 174–179. [5] A. Maresh, D.A. Preciado, A.P. O’Connell, G.H. Zalzal, A comparative analysis of open surgery vs endoscopic balloon dilation for pediatric subglottic stenosis, JAMA Otolaryngol. Head Neck Surg. 140 (10) (2014) 901–905. [6] R. Maunsell, M.A. Avelino, Balloon laryngoplasty for acquired subglottic stenosis in children: predictive factors for success, Braz. J. Otorhinolaryngol. 80 (5) (2014) 409–415. [7] J.L. Wentzel, S.M. Ahmad, C.M. Discolo, M.B. Gillespie, A.M. Dobbie, D.R. White, Balloon laryngoplasty for pediatric laryngeal stenosis: case series and systematic review, Laryngoscope 124 (7) (2014) 1707–1712. [8] K. Yamamoto, P. Monnier, F. Holtz, Y. Jacquet, Laryngotracheal reconstruction for pediatric glotto-subglottic stenosis, Int. J. Pediatr. Otorhinolaryngol. 78 (9) (2014) 1476–1479. [9] https://www.nice.org.uk/guidance/ipg425/resources/guidance-endoscopicballoon-dilatation-for-subglottic-or-tracheal-stenosis-pdf. [10] G B.A. Warner, S. Patel, P. Martinez-Devesa, R. Corbridge, Otolaryngology and Head and Neck Surgery, OUP Oxford, Oxford, 2009 p. 681.
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Paediatric subglottic stenosis – Have things changed? Our experience from a developing tertiary referral centre Rishi Talwar *, Jagdeep Singh Virk, Yogesh Bajaj ENT Department, Barts Children’s and the Royal London Hospital, United Kingdom
A R T I C L E I N F O
A B S T R A C T
Article history: Received 31 March 2015 Received in revised form 20 August 2015 Accepted 21 August 2015 Available online 8 September 2015
Background: Paediatric airway disorders are common, particularly in the context of improved ventilation methods for neonates in intensive care units. Management is not standardised. Objectives: To assess the number, severity, management and outcomes of all patients diagnosed with subglottic stenosis at a developing tertiary referral centre. Study design: 19 month prospective longitudinal study. Study population: All patients who underwent microlaryngobronchoscopy (MLB) were included. Subglottic stenosis (SGS) was graded intraoperatively using the Myer–Cotton classification. Results: 102 patients underwent MLB during this period. 33 of 102 patients (32.4%) were diagnosed with SGS +/ other co-pathologies. Mean and median age at diagnostic procedure were 24.7 months (SD 23.5) and 18 months, respectively. At their first MLB, 22 of 33 patients (66.7%) were found to have a Grade 1 SGS, 7 of 33 (21.2%) were Grade 2 and the remaining 4 of 33 (12.1%) were Grade 3. We had no patients with Grade 4 SGS. During this period, these patients with SGS underwent 73 MLBs +/ interventions (2.21 per patient) such as incision and balloon dilatation, tracheostomy (2 of 33) or ultimately, laryngotracheal reconstruction (LTR) (2 of 33). A further 3 patients have since undergone LTR. No significant unexpected events occurred. Conclusions: These findings suggest that subglottic stenosis may be evolving in terms of its presentation and management. Management can more often be endoscopic and perhaps avoid tracheostomy or laryngotracheal reconstruction. Further long term prospective studies are required. ß 2015 Published by Elsevier Ireland Ltd.
Keywords: Subglottic stenosis Endoscope Laryngotracheal reconstruction Stridor Paediatric
1. Introduction
2. Materials and methods
Paediatric airway disorders are common, particularly in the context of improved ventilation methods for neonates in intensive care units. Subglottic stenosis (SGS) can be congenital or acquired, with the latter having a higher incidence, reported to be in the range of 1–8% after intubation [1]. Management is not standardised but endoscopic techniques are increasingly employed in the form of balloon laryngoplasty/dilatation [2–8]. Management must be tailored for each individual patient’s circumstances. The aim of this study was to assess the number, severity, management and outcomes of all patients diagnosed with subglottic stenosis by one team in our newly developing paediatric airway service at Barts Children’s and the Royal London Hospitals. This was in keeping with the current NICE guidelines on auditing airway and specifically balloon dilatation procedures [9].
Data was prospectively collected from March 2012 to November 2013. All patients who underwent microlaryngobronchoscopy (MLB) by the senior author and his team were included.
* Corresponding author at: ENT Department, Barts Children’s and Royal London Hospital, Whitechapel Road, Whitechapel, London E1 1BB, United Kingdom. Tel.: +44 0790 896 0034; fax: +44 0203 845 2964. E-mail address: [email protected] (R. Talwar). http://dx.doi.org/10.1016/j.ijporl.2015.08.031 0165-5876/ß 2015 Published by Elsevier Ireland Ltd.
2.1. Ethical considerations Ethical approval was not required by the hospital committee as the data was prospectively collated and standard management was not deviated from for these patients. 2.2. Surgical technique and peri-operative care All patients underwent our standard departmental anaesthetic induction with spontaneous ventilation. During each MLB, subglottic stenosis was graded intraoperatively using the Myer– Cotton classification to indicate the severity of the pathology, based on the size of an endotracheal tube fitting with a leak at 20 cm H2O. Suspension with a baby Benjamin laryngoscope was performed as required. Radial incisions were made (2–3) with a
R. Talwar et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 2020–2022
2021
sickle knife. Balloon dilatation was carried out dependent upon patient tolerance, i.e. how quickly the patient desaturated. Usually 2 dilatations for 45 s each were performed. The size of the balloon used was determined by the expected tracheal diameter based on the patient’s corrected age. Intraoperatively, all children, received one dose of steroid (dexamethasone). Post-operatively, all patients had regular observations, particularly their oxygen saturations and respiratory rate but were also monitored for any stridor. Anti-reflux medication was not routinely prescribed unless significant signs of reflux were found during the MLB or following combined laryngeal cleft repairs or laryngotracheal reconstruction. 3. Results 3.1. Microlaryngobronchoscopy (MLB) data 102 patients underwent MLB during this period. 33 of 102 patients (32.4%) were diagnosed with SGS +/ other co-pathologies. The vast majority of the other 69 patients had other pathologies, such as laryngomalacia, laryngeal cleft, haemangioma and vocal cord palsy. The commonest presenting complaints were recurrent croup and stridor. Indications for MLB included choking episodes, recurrent chest infections/croup, failure to thrive, noisy breathing and swallowing problems (following video fluoroscopy). All patients were initially assessed in the outpatient clinic or ward and underwent preoperative awake flexible nasolaryngoscopy assessment, as tolerated. Mean and median age at diagnostic procedure were 24.7 months (SD 23.5) and 18 months respectively. Mean follow up was 12 months. 3.2. Myer–Cotton grading At their first MLB, 22 of 33 patients (66.7%) were found to have a Grade 1 SGS, 7 of 33 (21.2%) were Grade 2 and the remaining 4 (12.1%) were Grade 3. We had no patients with a Grade 4 SGS (Figs. 1 and 2). All patients were symptomatic. Of note, 3 patients had no history of trauma or intubation and were presumed to be of congential origin.
Fig. 1. Distribution of subglottic stenosis according to the Myer–Cotton grading system.
3.3. Management During this period, these patients with SGS underwent 73 MLBs +/ interventions (2.21 per patient) such as incision and balloon dilatation, tracheostomy (2 of 33) or ultimately, laryngotracheal reconstruction (LTR) (2 of 33). A further 3 patients have since undergone LTR. Repeat dilatations were typically performed every 3 months (range 6 weeks to 6 months). Treatment was based upon the severity of symptoms and significance of the stenosis. Management was therefore on an individualised basis within a paradigm of endoscopic dilatations. With two of the grade 3 SGS patients, it became clinically apparent earlier, that they were not responding well to endoscopic management, both by measurement at MLB but also, more importantly, based upon the patients’ symptoms. Endoscopic management in these cases was therefore abandoned sooner, for
Fig. 2. Myer–Cotton grading of subglottic stenosis with endoscopic balloon dilatation. (A) Normal larynx, (B) Grade 1 SGS, (C) Grade 2 SGS, (D) Grade 3 SGS, (E) Balloon laryngoplasty.
R. Talwar et al. / International Journal of Pediatric Otorhinolaryngology 79 (2015) 2020–2022
2022
Table 1 Outcomes related to grade of subglottic stenosis. Myer–Cotton grade
Number of patients
Total number of MLB + intervention/dilatation (per patient)
Tracheostomy required (%)
LTR required (%)
1 2 3 4
22 7 4 0
44 (2.00) 20 (2.86) 9 (2.25) N/A
0 0 2a (50%) N/A
0 0 2 (50%) N/A
33
73 (2.21)
2 (6%)
2 (6%)
Overall a
Both ultimately required LTR.
the relatively safer option of a tracheostomy and ultimately LTR (Table 1). 3.4. Complications We had no deaths and no significant unexpected events in these patients. 4. Discussion 4.1. Synopsis of key findings Approximately one-third (32.4%) of the patients presenting to our paediatric airway department who required a MLB were found to have SGS. Of these, approximately 1 in 6 will require definitive management with a LTR, sometimes requiring a tracheostomy to stabilise the patient and enable them to grow pre-LTR. The remainder were managed endoscopically, either with monitoring +/ medications or repeated balloon dilatations (Fig. 2). This appears to be a significantly higher rate of SGS as compared to the 21% presented by Bailey et al. in 2006, based on data collected at Great Ormond Street Hospital over 5 years [10]. We propose that this higher than expected rate may be due to a number of reasons. These include increased survival of pre-term neonates with congenital abnormalities and acquired SGS secondary to intubation, alongside improved diagnostic rates with increasing safety and thus use of MLB. In our series, there were a few likely congenital SGS, given that these patients had no history of trauma or intubation. These were managed in the same manner but given our sample size, no conclusions can be drawn based on statistical significance between these 2 sub-groups, of presumed congenital versus acquired SGS. We further suggest that while the more severe grades of SGS previously had to be managed definitively by tracheostomy or LTR, it now appears that an increasing proportion of these can be managed effectively using endoscopic methods. A number of recent studies confirm that balloon laryngoplasty may be considered the first line treatment for subglottic stenosis, particularly for the acquired subtype [3,6]. A systematic review concluded that balloon dilatation for subglottic stenosis was a highly effective, low risk alternative or adjunct to traditional reconstructive procedures [7]. The caveat remains the severe SGS subgroup, in that these patients have an increased risk of treatment failure with balloon laryngoplasty alone with suggestions that, in some cases, failed balloon dilatation cases may lead to detrimental effects including an increased risk of unplanned urgent interventions as compared with LTR [4,5]. This was indeed borne out in our series, in which all grade 3 SGS, ultimately required a laryngotracheal reconstruction, which remains an important, relatively safe and viable option for these patients [2,8]. In addition, experientially, acute forms of SGS appeared to respond better than chronic SGS patients. However, further data are required to elucidate this further as very few patients with a truly acute subglottic injury were treated in our series.
4.2. Limitations This study reflects the needs of our population and may not be generalisable. We recommend further prospective studies to collate data from all paediatric centres. The national paediatric airway registry is currently being set up and will be invaluable in this regard. We should also note the role of selection bias as only children selected for MLB are included in this series. As a corollary to this, awake flexible nasolaryngoscopy can help identify glottic and supraglottic pathology. However, we believe that, although useful, awake assessment cannot reliably evaluate the subglottis for copathologies. 5. Conclusion We present our experience at a developing single specialist centre and our findings suggest that subglottic stenosis may be evolving in terms of its presentation and management. These findings are also suggested based on UK hospital episode statistical data from 2004 to 2014. Management can more often be endoscopic and hence avoid tracheostomy or laryngotracheal reconstruction. Further long term prospective studies are required to confirm the reproducibility of these successful outcomes. Conflict of interest None. Financial disclosures None. References [1] M.S. Morrissey, C.M. Bailey, Diagnosis and management of subglottic stenosis after neonatal ventilation, Arch. Dis. Child. 65 (10) (1990) 1103–1104. [2] Y. Bajaj, L.A. Cochrane, C.G. Jephson, M.E. Wyatt, C.M. Bailey, D.M. Albert, et al., Laryngotracheal reconstruction and cricotracheal resection in children: recent experience at Great Ormond Street Hospital, Int. J. Pediatr. Otorhinolaryngol. 76 (4) (2012) 507–511. [3] A. Filiz, S.O. Ulualp, Long-term outcomes of balloon dilation for acquired subglottic stenosis in children, Case Rep. Otolaryngol. 2014 (2014) 304593. [4] M. Lang, S.E. Brietzke, A systematic review and meta-analysis of endoscopic balloon dilation of pediatric subglottic stenosis, Otolaryngol. Head Neck Surg. 150 (2) (2014) 174–179. [5] A. Maresh, D.A. Preciado, A.P. O’Connell, G.H. Zalzal, A comparative analysis of open surgery vs endoscopic balloon dilation for pediatric subglottic stenosis, JAMA Otolaryngol. Head Neck Surg. 140 (10) (2014) 901–905. [6] R. Maunsell, M.A. Avelino, Balloon laryngoplasty for acquired subglottic stenosis in children: predictive factors for success, Braz. J. Otorhinolaryngol. 80 (5) (2014) 409–415. [7] J.L. Wentzel, S.M. Ahmad, C.M. Discolo, M.B. Gillespie, A.M. Dobbie, D.R. White, Balloon laryngoplasty for pediatric laryngeal stenosis: case series and systematic review, Laryngoscope 124 (7) (2014) 1707–1712. [8] K. Yamamoto, P. Monnier, F. Holtz, Y. Jacquet, Laryngotracheal reconstruction for pediatric glotto-subglottic stenosis, Int. J. Pediatr. Otorhinolaryngol. 78 (9) (2014) 1476–1479. [9] https://www.nice.org.uk/guidance/ipg425/resources/guidance-endoscopicballoon-dilatation-for-subglottic-or-tracheal-stenosis-pdf. [10] G B.A. Warner, S. Patel, P. Martinez-Devesa, R. Corbridge, Otolaryngology and Head and Neck Surgery, OUP Oxford, Oxford, 2009 p. 681.