Type 1 laryngeal cleft management: a pediatric tertiary care center case series

Introduction

Laryngeal cleft (LC) is a congenital condition in which there is an opening between the larynx and esophagus, leading to several complications, including aspiration, chronic cough, choking, airways symptoms such as respiratory infections and pneumonia (1-3). While LC is a rare condition, it is becoming more prevalent as the pediatric otolaryngology literature expands (4). Several studies have reported that there is a prominent or slight male predominance in patients with LC (1,4-7). Patients with LC can present with a variety of symptoms including dysphagia, choking, or persistent coughing (8). LC can be diagnosed using both microlaryngoscopy and bronchoscopy (9). Treatment of LCs includes observation, laryngoplasty injections, or surgical management, and it varies depending on several factors (1).

LC starts during the development of the foregut, where the respiratory diverticulum is formed ventrally and continues to develop caudally (4). To separate the respiratory diverticulum from the primitive gut tube, mesenchymal tissue is formed between the two to close them, but they remain attached to each other while the respiratory diverticulum descends and bifurcates to form the trachea. The two are normally separated by apoptosis of the cells connecting them. In LC patients, the opening between the respiratory diverticulum and primitive gut tube persists and can remain open as the respiratory diverticulum migrates caudally (4). However, the etiology of LC remains unclear (10). There are four types of LC. Cricoid cartilage can be used to differentiate between types 1 and 2. Type 1 LC does not extend into the cricoid cartilage, whereas type 2 LC does (8). Type 3 extends beyond the cricoid cartilage into the cervical trachea, whereas type 4 extends into the thoracic trachea (8). Figure 1 shows the different types of LC according to Benjamin-Inglis and Evan’s classification system (11).

Figure 1 Types of laryngeal clefts according to Benjamin-Inglis and Evan’s classification system for laryngeal clefts.

In our tertiary care hospital, we are managing symptomatic patients who were diagnosed with type 1 LC and failed conservative treatment initially with hyaluronic acid (HA) injection, followed by frequent follow-up in the outpatient clinic. If symptoms recur, surgical repair is the second management line. Before any further intervention, all patients should initially be evaluated in the clinic with the transnasal fiberoptic laryngoscopy (TNFL) to roll out other possible related causes. The swallowing assessment which includes functional endoscopic evaluation of swallowing with or without modified barium swallow (MBS) is considered a crucial part in the evaluation of such a patient, it can demonstrate the presence or absence of silent aspiration with an illustration whether there is a swallowing problem or not (12).

HA injection is a safe technique that could be associated with a 50% chance of improvement within the first 30 days of injection and may avoid the need for surgical repair (13). Nevertheless, endoscopic surgical repair is considered the most effective management option for patients with type 1 LC with several possible ways to denude the inter-arytenoid area that is going to be sutured, whether cold steel or carbon dioxide (CO₂) laser, or coblation technique (6,14,15). In a recent study that compared CO₂ versus cold techniques, it was reported that 3.1% of the cold steel group of patients with LC who underwent surgical repair had cleft breakdown following surgery, while 18.9% of the laser group had cleft breakdown (14). Although laser repair has a success rate of 81.1%, it carries an 18.9% risk of recurrence, making cold steel the preferred technique (14). Laser repair has also been reported to fail earlier than cold steel repair following surgery; however, this was not statistically significant (14). A previous study conducted in our pediatric tertiary care center reported rare complications of laser repair, including a small gap, short epiglottic fold, and intra-arytenoid fibrous band (16).

This study aimed to review the clinical presentations, investigations, comorbidities, management options, recurrence, outcomes, and to draw a management algorithm for patients with type 1 LC who presented to our pediatric tertiary care center. We present this article in accordance with the AME Case Series reporting checklist (available at https://acr.amegroups.com/article/view/10.21037/acr-24-149/rc).

Case presentation

This was a tertiary care center retrospective case series that reviewed charts of patients with LC type 1 admitted to our pediatric tertiary care center between January 2020 and January 2022. We obtained several variables, including patient demographics such as age at diagnosis, sex, height, and weight. We also collected data regarding clinical presentation, such as coughing, choking, and airway symptoms, as well as scope findings, swallowing assessment and upper gastrointestinal (UGI) series. Additionally, data on comorbidities including gastroesophageal disease (GERD), aspiration pneumonia, neurological disease, genetic syndrome, and other comorbidities were collected. We also collected data regarding management, including direct laryngobronchoscopy (DLB) status, HA injection, endoscopic laser repair, and data regarding follow-up, improvement, recurrence, and management after recurrence. Data were collected from the medical records of King Abdullah Specialist Children’s Hospital. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committees and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patients’ legal guardians for publication of this case series and accompanying images. A copy of the written consent is available for review by the editorial office of this journal. All data are presented as mean ± standard deviation (SD).

Six patients with LC type 1 were included in this case series (Tables 1-4). Their mean age was 22.5 months (SD: 17.1). All patients were male, except for one. The mean weight was 12.2 kg (SD: 5.3). The mean height was 84.2 cm (SD: 23.9). All patients experienced cough and choking with feeding. Of the six patients, five had no airway symptoms and two had a stridor. A management algorithm approach of type 1 LC can be seen in Figure 2.

Figure 2 A management algorithm approach of type 1 laryngeal cleft. TNFL, transnasal fiberoptic laryngoscopy; HA, hyaluronic acid; HDU, high dependency unit; FU, follow-up; LC, laryngeal cleft; PICU, pediatric intensive care unit; NGT, nasogastric tube.

Case 1

A 4-year-old boy known to have bronchial asthma presented to the Pediatric Otolaryngology Airway Clinic experiencing frequent choking while he is feeding. He had one history of hospital admission due to viral bronchiolitis with Frequent Emergency Department visits because of cough and bronchial asthma exacerbation. His weight, height, and head circumferences were all normal for his age regarding Growth Chart. On examination, TNFL was done with a normal finding. Additionally, swallowing assessment and UGI series were all unremarkable for any aspiration or other abnormalities.

To begin with, the patient was taken to the operative room for DLB which revealed type 1 LC as can be seen in Figure 3. Furthermore, 4 mm HA was injected into the intra-arytenoid area through suspension laryngoscopy and extubated successfully as can be seen in Figure 4. Postoperatively, the patient was sent to the high dependency unit (HDU) for 24-hour observation and was given acetaminophen 15 mg/kg/dose each 8 hours, 3 doses of intravenous dexamethasone 0.2 mg/kg/dose, and omeprazole 1 mg/kg/dose once daily for 3 months. Day 1 postoperative, the patient was seen and assessed, his vital signs were stable, no airway symptoms, swallowing assessment was unremarkable. Post injection scope view can be seen in Figure 5. He was tolerating pure oral feeding without choking; therefore, he was discharged on previously mentioned medications, and he was totally asymptomatic for a period of a month.

Figure 3 Case 1 upon probe examination showed type 1 laryngeal cleft.

Figure 4 Case 1 post injection 0.4 cc of hyaluronic acid.

Figure 5 Case 1 post repair.

After 2 months of the injection laryngoplasty, the patient again presented to the Pediatric Otolaryngology Airway Clinic with 1-month history of on-off choking without any other airway symptoms. He was taken to the operative room, DLB showed a re-demonstration of type 1 LC, micro laryngoscopy with a CO₂ laser was used to denude the intra-arytenoid area, and 3 sutures of 5-0 polydioxanone suture (PDS) were utilized to repair the cleft (Figure 6A,6B). Moreover, a release of 1 mm aryepiglottic fold was done to avoid narrowing of supraglottic area. The patient is then sent intubated on nasogastric tube (NGT) to the pediatric intensive care unit (PICU) for observation. He was on sedations, and previously mentioned medication regimen that was used in first admission. In addition, he was evaluated by a nutritionist, with a daily requirement of the following: energy 64 kcal/kg, protein 1.5 gm/kg, and fluid 110 mL/kg which was achieved by the intake of pediasure 50 mL/h through NGT. Day 4 postoperative, swallowing assessment was done and it was unremarkable, so the decision was made to remove the NGT and to start on a pure diet with a thickened-up powder. The patient was discharged in a normal stable condition and was given a couple of follow up appointments with swallowing assessment, and he was totally fine and asymptomatic.

Figure 6 Use of 5-0 polydioxanone suture to repair the cleft.

Case 2

A 6-month preterm boy, gestational age: 33 weeks, with previous history of neonatal intensive care unit admission and short period of intubation due to respiratory distress, presented to the Pediatric Otolaryngology Airway Clinic and was experiencing choking attacks while he was feeding, associated with on-off inspiratory stridor while he is crying or when he was lying in supine position. TNFL showed moderate laryngomalacia. The probe view showed G1 LC as can be seen in Figure 7. His growth parameters were appropriate for his age and no failure to thrive at time of presentation. Swallowing assessment was done and it was unremarkable.

Figure 7 Case 2 upon probe examination showed type 1 laryngeal cleft.

He was taken to the operating room for DLB which showed a type 1 LC and short aryepiglottic folds. Injection of 2 mm HA in the intra-arytenoid area was done, release of bilateral aryepiglottic folds was done as well. The patient was extubated in the operating room successfully and smoothly and was sent to the PICU for 24 hours observation observation with: intravenous dexamethasone 2 mg/kg/day divided into 4 doses, omeprazole syrup 1 mg/kg/day divided into 2 doses for 2 months and acetaminophen 15 mg/kg/dose each 6 hours for 10 days. He was discharged on the second day in a good and stable condition and was asymptomatic when he was seen as a follow up in the clinic without any significant scope findings for a couple of months.

After 4 months, he again presented to the Pediatric Otolaryngology Airway Clinic experiencing choking attacks for 3 weeks, no respiratory symptoms were appreciated and TNFL was unremarkable. Second surgery was conducted for him, suspension laryngoscopy and CO₂ laser repair, with setting of 10 watts, super pulse repeat mode, 1.5 mm shape size, and 1 mm depth, utilizing 3 sutures of 5-0 double needles PDS. Additionally, supraglottoplasty and release of the aryepiglottic folds bilaterally to avoid narrowing of upper airway was also achieved. At the end of operation, insertion of NGT for feeding was done and he was sent to PICU intubated and sedated in stable condition for 24-hour observation with the same previous medical regimen mentioned before. Furthermore, he was seen by the nutrition, and was put on a nutritional goal of; 1,091.4 kcal/day (102 kcal/kg), protein 12.8 gm/day (1.2 gm/kg), and this goal was achieved by pediasure NGT feeding rate of 35 mL/h. Day one postoperative, the patient was extubated successfully, bottle feeding has started after NGT was removed, and he was observed in a regular ward for 2 days with uneventful condition, therefore he was discharged and followed up in the clinic without any significant symptoms and signs with completely improvement in terms of choking episodes.

Case 3

A 23-month-old boy known to have a stable congenital heart disease, presented to the Pediatric Otolaryngology Airway Clinic experiencing choking attacks during feeding with a history of aspiration pneumonia requiring admission two times. There was no history of any airway symptoms and his growth parameters were appropriate to his age. TNFL and swallowing assessment were unremarkable, DLB was done in another hospital and showed type 1 LC.

He was taken to an operative room for DLB and suspension laryngoscopy which confirmed the previous mentioned finding, and the plan was conducted for repair rather than injection. CO₂ laser has used, setting of; 10 watts, and ultra-pulse mode with utilizing three interrupted sutures of 4-O PDS with double needles to repair the inter-arytenoid type 1 LC was achieved. Postoperatively, he was sent to PICU intubated on sedation and on NGT feeding for 24 observations with the same previous medical regimen and nutritional goal mentioned before. Day 1, patient has extubated successfully and discharged after a couple of days with a stable uneventful condition. He was then seen in the clinic 1 month later and he was totally free from any choking or airway symptoms.

Case 4

A 3-year-old boy, known to have bronchial asthma, GERD, central hypotonia, and COL6A2 gene clinic phenotype (Bethlem myopathy 1), presented to the Pediatric Otolaryngology Airway Clinic experiencing frequent choking while he was feeding. He had multiple hospital admissions due to aspiration pneumonia. His weight, height, and head circumferences were all normal for his age on the Growth Chart. On examination, TNFL was done with normal findings. Additionally, swallowing assessment and UGI series were all unremarkable.

To begin with, the patient was taken to the operative room for DLB which revealed type 1 LC. Furthermore, 1 mm HA was injected into the intra-arytenoid area through suspension laryngoscopy and extubated successfully. A scope view of pre and post injection larynx can be seen in Figures 8,9, respectively. Postoperatively, the patient was sent to the HDU for 24-hour observation and was given acetaminophen 15 mg/kg/dose each 8 hours, 3 doses of intravenous dexamethasone 0.2 mg/kg/dose, and omeprazole 1 mg/kg/dose once daily for 3 months. Day 1 postoperative, the patient was seen and assessed, his vital signs were stable, no airway symptoms, swallowing assessment was unremarkable, he was tolerating pure oral feeding without choking, therefore he was discharged on previously mentioned medications, and he was totally asymptomatic for a period of a month.

Figure 8 Case 4 pre injection.

Figure 9 Case 4 post injection.

After 3 months of the injection laryngoplasty, the patient again presented to the Pediatric Otolaryngology Airway Clinic with 2 weeks history of on-off choking without any other airway symptoms. He was taken to the operative room, DLB showed a re-demonstration of type 1 LC, micro laryngoscopy with a CO₂ laser was used to denude the intra-arytenoid area, and 3 sutures of 5-0 PDS were utilized to repair the cleft. Moreover, supra-glottoplasty was done to avoid narrowing of supraglottic area. The patient is then sent intubated on NGT to the PICU for observation. He was on sedations, and previously mentioned medication regimen that was used in first admission. In addition, he was evaluated by a nutrition, with a daily requirement of the following; energy 115 kcal/kg, protein 2 gm/kg, and fluid 110 mL/kg which was achieved by the intake of Peptamen JR 30 mL/h through NGT. The patient was discharged in a normal stable condition and was given a follow up appointment, and he was totally fine and asymptomatic.

Case 5

A 15-month full-term boy, known to have bronchial asthma and GERD, presented to the Pediatric Otolaryngology Airway Clinic and was experiencing choking attacks while he was feeding with no associated stridor or other airway symptoms. TNFL was unremarkable. He had multiple hospital admissions due to aspiration pneumonia. His growth parameters were appropriate for his age and no failure to thrive at time of presentation. Swallowing assessment was done and it was unremarkable. A probe view below the level of vena contracta can be seen in Figure 10.

Figure 10 Case 5 probe below the level of vena contracta.

He was taken to the operating room for DLB which showed a type 1 LC with redundant mucosa with adhesions between the epiglottis and arytenoids. Injection of 2 mL HA in the intra-arytenoid area was done. A post injection view can be seen in Figure 11. Then, adhesions were release by a cold technique using scissors. The patient was extubated in the operating room successfully and smoothly and sent to the PICU for 24 hours observation on; intravenous dexamethasone 2 mg/kg/day divided into 4 doses, omeprazole syrup 1 mg/kg/day divided into 2 doses for 2 months, and acetaminophen 15 mg/kg/dose each 6 hours for 10 days. He was discharged on the second day in a good and stable condition and was asymptomatic when he was seen as a follow up in the clinic without any significant scope findings for a couple of months.

Figure 11 Case 5 post injection.

After 2 months, he again presented to the Pediatric Otolaryngology Airway Clinic with no complaints, no respiratory symptoms were appreciated and TNFL was unremarkable. Patient was doing fine and following with airway clinic, with no disease recurrence yet.

Case 6

A 6-month-old full-term girl, known to have severe combined immunodeficiency, Ommen syndrome, and congenital athymia (FOXN1 deficiency), presented to the Pediatric Otolaryngology Airway Clinic and was experiencing choking attacks while she was feeding associated with on-off inspiratory stridor and aspiration. TNFL showed a picture of moderate laryngomalacia. Her growth parameters were appropriate for her age and no failure to thrive at time of presentation. Swallowing assessment was done and it showed oro-pharyngeal dysphagia with absent swallow reflux.

She was taken to the operating room for DLB which showed deep inter-arytenoid notch (no cleft), posteriorly displaced and tubular shaped epiglottis, extremely short aryepiglottic folds, and signs of severe reflex. Injection of 2 mL HA in the intra-arytenoid area was done, release of bilateral aryepiglottic folds was done as well as debulking of right redundant arytenoid mucosa. The patient was extubated in the operating room successfully and smoothly and sent to the PICU for 24 hours observation with: intravenous dexamethasone 2 mg/kg/day divided into 4 doses, omeprazole syrup 1 mg/kg/day divided into 2 doses for 2 months, and acetaminophen 15 mg/kg/dose each 6 hours for 10 days. She was discharged on the second day in a good and stable condition and was asymptomatic when she was seen as a follow-up in the clinic without any significant scope findings for a couple of months. After 2 months, she presented to the Pediatric Otolaryngology Airway Clinic with no complaints, no respiratory symptoms were appreciated and TNFL was unremarkable. The patient was doing fine and following up at airway clinic, with no disease recurrence yet.

Discussion

In this case series, we aimed to review the clinical presentations, investigations, comorbidities, management options, recurrence, and outcomes of patients with type 1 LC who presented at our pediatric tertiary care center. All the patients presented with coughing and choking. Most of the patients had unremarkable scope findings. All patients had GERD, and most had aspiration pneumonia. Only one patient had a genetic mutation. Half of the patients had bronchial asthma. Half of the patients were treated with two mL of HA in addition to supraglottoplasty. Most patients had a follow-up two to three weeks after treatment. Half of the patients had recurrent symptoms after the injections and were eventually treated with endoscopic laser repair.

Age at diagnosis and sex predominance

In the current case series, the age at diagnosis ranged from six months to four years. This is similar to a previous case series conducted at the same center, where the age at diagnosis ranged from three months to three years (16). In contrast, Jorgensen et al. reported that the age at diagnosis ranged from two years and one month to three years and one month (17). In this study, most patients were male. It has been reported in the literature that there is a slight to moderate male predominance in patient with LC (1,4,18). However, a review by El-Hakim mentioned that sex predominance could not be determined because most published studies had a low number of patients to make such conclusions (4).

Clinical presentation and comorbidities

All the patients in our case series presented with coughing and choking, and none of them had airway symptoms, except two patients who had stridor. Conversely, a recent systematic review and meta-analysis conducted by Reddy et al. that included 713 patients reported that the most common presentations of type 1 LC were aspiration, dysphagia, and choking (19). Furthermore, the same review reported that recurrent pneumonia, chronic bronchitis, and wheezing were more common than stridor, which was the only airway symptom reported in this case series (19). All patients had GERD, and most had aspiration pneumonia in our case series. Similarly, Reddy et al. reported that the most common type 1 LC comorbidities were aspiration (80.1%) and GERD (67.9%) (19).

Aspiration pneumonia is a severe complication of LC (20). A recent retrospective study reported that 41% of LC patients developed aspiration pneumonia (20). In the current study, 66% of the patients with type 1 LC had aspiration. While patients with LC usually present with coughing, LC should not be excluded with absent coughing because silent aspiration is significantly associated with LC (20). The larger the cleft, the worse are the symptoms of aspiration pneumonia (21).

Diagnostic modalities and investigations

Patients presenting with type 1 LC can be diagnosed based on clinical presentation or through investigations such as endoscopy, radiography, and computerized tomography (CT) scans (18). Swallowing assessment with or without MBS is inevitable as initial clinical evaluation for all patients with expectable LC; it provides evidence for the presence or absence of silent aspiration with elaboration of swallowing phases and any possible related disorders (12). In this study, we diagnosed type 1 LC with DLB.

Associated syndromes and genetic mutations

LC can be a part of a genetic syndrome. Most notably, Pallister Hall syndrome is associated with type 1 LC, a disorder that affects many parts of the body and can present with fusion of fingers or toes or the development of extra fingers and toes (22). In our case series, only one patient has a genetic mutation which was a variant of bethlem myopathy. Although type 1 LC is considered a sporadic condition, a recent study reported that genetic factors may be important; thus, considering family history can be helpful in diagnosing type 1 LC (7).

Management options

In a previous retrospective analysis that included seven patients with type 1 LC, all patients were diagnosed using microlaryngoscopy and bronchoscopy (9). This is similar to our case series, where we managed patients with HA. Half of the patients had two mL of HA in addition to supraglottoplasty. In contrast, the case series by Newberry et al. reported that out of seven patients with type 1 LC, three were managed with observation, three were managed with injection laryngoplasty, and one was managed with endoscopic repair (9). A recent systematic review and meta-analysis conducted by Reddy et al. that included 713 patients with type 1 LC reported that 38% of patients were managed with injection laryngoplasty as the initial treatment option, while 54% were managed with endoscopic surgical repair as the initial treatment (19). The previous study concluded that while both management options were effective, endoscopic surgical repair remains the gold standard management option, as it has fewer complications. They also reported that injection laryngoplasty might be the preferred option for children under the age of two. The management algorithm approach of type 1 LC that we followed can be seen in Figure 2.

In our tertiary care hospital, we initially managed patients with type 1 LC with HA injections for a few months, depending on the severity of the condition, followed by follow-up of the patient. If coughing and/or choking reoccur or persists, surgical repair is the next management option. Although conservative therapy has been useful for 36% of patients with type 1 LC, endoscopic surgical repair remains the optimal management choice (6). We advocate for injection laryngoplasty as a trial to confirm the diagnosis and anticipated benefit from endoscopic surgical repair as it offers less invasive management option and decrease the risk of developing potentially life-threatening complications.

Recurrence and management after recurrence

Recurrence of type 1 LC is mostly associated with injection laryngoplasty (19). However, in our pediatric tertiary care center, we managed all patients with type 1 LC using injections as a temporary treatment. Five of our six patients had recurrent symptoms and underwent endoscopic laser repair. It is considered the optimal management choice with a lower risk of recurrence, as well as the management choice for LC breakdown following initial management, whether by injection laryngoplasty or endoscopic laser repair (18,19). The timeline for recurrence was as follows: patients underwent injection laryngoplasty then they had a follow-up two to three weeks from the injections. They also had a follow-up after two to three months from the injections to monitor for recurrence. We checked if they experienced coughing/choking in addition to utilizing swallowing assessments which included functional endoscopic evaluation of swallowing with or without MBS.

Limitations

While this case series highlights management options for type 1 LC, this study has several limitations. First, this study utilized a retrospective chart review, which limited the assessment of management choices in a randomized, controlled, and blinded manner. Second, this study was conducted in a single center and population; thus, its results may not be generalizable to national and international levels. Third, the number of included patients was low, mostly because LC is a rare condition. Future studies should include prospective multicenter studies with larger and more diverse populations to assess the most effective management options and increase generalizability at national and international levels. Future researchers can also consider using more permanent or long-lasting materials like fat or calcium hydroxyapatite for injection laryngoplasty since the literature is scarce in that aspect.

Conclusions

Type 1 LC is a rare congenital condition that can present as coughing and choking. It is associated with certain comorbidities such as GERD and aspiration pneumonia. Type 1 LC was initially managed with HA injection as a temporary treatment. Endoscopic surgical repair is the gold standard treatment for type 1 LC. The risk of recurrence after initial management is high; however, recurrent symptoms can be treated with endoscopic surgical repair. We advocate for injection laryngoplasty as a trial to confirm the diagnosis and anticipated benefit from endoscopic surgical repair as it offers less invasive management option and decrease the risk of developing potentially life-threatening complications. This case series adds to the scarce literature on LC in pediatric otolaryngology.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the AME Case Series reporting checklist. Available at https://acr.amegroups.com/article/view/10.21037/acr-24-149/rc

Peer Review File: Available at https://acr.amegroups.com/article/view/10.21037/acr-24-149/prf

Funding: None.

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://acr.amegroups.com/article/view/10.21037/acr-24-149/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committees and with the Helsinki Declaration (as revised in 2013). Written informed consent was obtained from the patients’ legal guardians for publication of this case series and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

References

1. Martha VV, Vontela S, Calder AN, et al. Laryngeal cleft: A literature review. Am J Otolaryngol 2021;42:103072. [Crossref] [PubMed]
2. Mukerji SS, Yenduri NJS, Chiou E, et al. A multi-disciplinary approach to chronic cough in children. Laryngoscope Investig Otolaryngol 2022;7:409-16. [Crossref] [PubMed]
3. Nguyen J, Ongkasuwan J, Anand G, et al. Combined laryngeal cleft injection laryngoplasty and salivary botulinum toxin for saliva aspiration. Laryngoscope Investig Otolaryngol 2022;7:1194-9. [Crossref] [PubMed]
4. Isaac A, El-Hakim H. Type 1 Laryngeal Cleft and feeding and swallowing difficulties in infants and toddlers: A Review. Clin Otolaryngol 2019;44:107-13. [Crossref] [PubMed]
5. García-Muro C, Sáenz-Moreno I, Gómez-Sáez F, et al. Type 2 laryngeal cleft associated with OpitzG/BBB syndrome. Acta Otorrinolaringol Esp (Engl Ed) 2022;73:196-8. [Crossref] [PubMed]
6. Ojha S, Ashland JE, Hersh C, et al. Type 1 laryngeal cleft: a multidimensional management algorithm. JAMA Otolaryngol Head Neck Surg 2014;140:34-40. [Crossref] [PubMed]
7. Dombrowski ND, Li Y, Zhao CX, et al. Familial and genetic factors in laryngeal cleft: Have we learned anything? Int J Pediatr Otorhinolaryngol 2020;138:110283. [Crossref] [PubMed]
8. Miller AL, Hersh CJ, Johnson KE, et al. Short-term swallowing outcomes following type 1 laryngeal cleft injection. Int J Pediatr Otorhinolaryngol 2019;116:159-63. [Crossref] [PubMed]
9. Newberry CI, Carpenter P, McCrary H, et al. Inter-rater reliability in diagnosis and treatment of type one laryngeal cleft: A blinded observational study. Int J Pediatr Otorhinolaryngol 2020;139:110475. [Crossref] [PubMed]
10. Pezzettigotta SM, Leboulanger N, Roger G, et al. Laryngeal cleft. Otolaryngol Clin North Am 2008;41:913-33. ix. [Crossref] [PubMed]
11. Benjamin B, Inglis A. Minor congenital laryngeal clefts: diagnosis and classification. Ann Otol Rhinol Laryngol 1989;98:417-20. [Crossref] [PubMed]
12. Strychowsky JE, Dodrill P, Moritz E, et al. Swallowing dysfunction among patients with laryngeal cleft: More than just aspiration? Int J Pediatr Otorhinolaryngol 2016;82:38-42. [Crossref] [PubMed]
13. Miller AL, Caloway C, Hersh CJ, et al. Long-term swallowing outcomes following type 1 laryngeal cleft injection. Int J Pediatr Otorhinolaryngol 2020;128:109731. [Crossref] [PubMed]
14. Kou YF, Kavoosi T, Redmann A, et al. Endoscopic Repair of Type 1 Laryngeal Clefts and Deep Interarytenoid Notches: Cold Steel Versus Laser. Laryngoscope 2021;131:2805-10. [Crossref] [PubMed]
15. Shah HP, Brawley CC, Maurrasse S, et al. Pediatric laryngeal cleft repair with coblation: Functional comparison of a novel technique with traditional methods. Int J Pediatr Otorhinolaryngol 2022;163:111378. [Crossref] [PubMed]
16. Aljomah D, Alshammari J. Laser Assisted Double-Layer Endoscopic Repair of Laryngeal Clefts: Our Experience in 11 Cases. Indian J Otolaryngol Head Neck Surg 2017;69:307-12. [Crossref] [PubMed]
17. Jorgensen C, Trivedi A, Cheng A, et al. Laryngeal cleft—case series from a surgical neonatal intensive care unit. Aust J Otolaryngol 2018;1:10. [Crossref]
18. Leboulanger N, Garabédian EN. Laryngo-tracheo-oesophageal clefts. Orphanet J Rare Dis 2011;6:81. [Crossref] [PubMed]
19. Reddy P, Byun YJ, Downs J, et al. Presentation and management of type 1 laryngeal clefts: A systematic review and meta-analysis. Int J Pediatr Otorhinolaryngol 2020;138:110370. [Crossref] [PubMed]
20. Velayutham P, Irace AL, Kawai K, et al. Silent aspiration: Who is at risk? Laryngoscope 2018;128:1952-7. [Crossref] [PubMed]
21. Mandadi AR, Saeed W, Suneja U, et al. A Mild Laryngeal Cleft Causes Severe Symptoms. Pediatr Emerg Care 2019;35:e47-8. [Crossref] [PubMed]
22. Brown C, Moore SH, Nagy M. Pallister Hall Syndrome: Laryngeal Anomalies and Failure to Thrive. Ear Nose Throat J 2021;100:606S-7S. [Crossref] [PubMed]