These authors contributed equally to this work.
In this study, we review our institutional experience with pediatric laryngomalacia (LM) and report our experiences of patients undergoing supraglottoplasty using the spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen (STRIVE Hi) technique.
The medical records of 29 children with LM who visited Seoul National University Hospital between January 2017 and March 2019 were retrospectively reviewed. Surgical management was performed using the STRIVE Hi technique. Intraoperative findings and postoperative surgical outcomes, including complications and changes in symptoms and weight, were analyzed.
Of the total study population of 29 subjects, 20 (68.9%) were female. The patients were divided according to the Onley classification as follows: type I (n=13, 44.8%), II (n=10, 34.5%), and III (n=6, 20.7%). Twenty-five patients (86.2%) had comorbidities. Seventeen patients (58.6%) underwent microlaryngobronchoscopy under STRIVE Hi anesthesia. Four patients with several desaturation events required rescue oxygenation by intermittent intubation and mask bagging during the STRIVE Hi technique. However, the procedure was completed in all patients without any severe adverse effects. Overall, 15 children (51.7%) underwent supraglottoplasty, of whom 14 (93.3%) showed symptom improvement, and their postoperative weight percentile significantly increased (
The STRIVE Hi technique is feasible for supraglottoplasty in LM patients, while type III LM patients with micrognathia or glossoptosis may have a higher risk of requiring rescue oxygenation during the STRIVE Hi technique.
Laryngomalacia (LM) is the most common (45%–75%) cause of congenital stridor, characterized by inward collapse of laryngeal structures, resulting in a narrow air passage and turbulent airflow that causes inspiratory stridor [
Although most LM patients are managed with conservative medical therapy, patients with severe disease whose symptoms worsen despite treatment require surgical intervention under general anesthesia [
The spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen (STRIVE Hi) technique is a tubeless, spontaneous-respiration anesthesia technique that uses total intravenous anesthesia in combination with high-flow nasal oxygen [
A retrospective review of medical records was performed for children with LM diagnosed and treated at Seoul National University Hospital from January 2017 to March 2019. Each subject underwent an evaluation that included history-taking, physical examination, and flexible laryngoscopy. Patients who were not followed up were excluded. The study population consisted of 29 patients diagnosed with LM by flexible laryngoscope examination. Type classification was performed based on the transnasal fiberoptic exam according to Olney’s classification [
Microlaryngobronchoscopy was considered for airway evaluation and accurate diagnosis in patients whose symptoms could not be controlled by conservative medical therapy. After conducting microlaryngobronchoscopy, the surgery, including supraglottoplasty, was determined as necessary. Indications for supraglottoplasty included severe airway obstruction presenting with significant chest retraction, bodyweight percentile <5%, or failure to thrive [
Starting with 3 minutes of preoxygenation, an AIRVO humidifier high-flow system (Fisher & Paykel, Auckland, New Zealand) was used. The flow rate was set to 2 L/min/kg and the FiO2 was set to 1.0 and routinely reduced to <0.3 while using the CO2 laser. Intravenous (IV) 1% lidocaine and 1% propofol were administered during induction, and general anesthesia was maintained by IV infusion of propofol (100–250 µg) and remifentanil (0.01–0.1 µg/kg/min). The sedative infusion rate was maintained at a level to avoid undesirable events (patient movement, laryngotracheal spasm) while preserving the patient’s self-respiration. Noninvasive blood pressure and pulse oximetry (SpO2), as well as electrocardiography and oxygen reserve index (ORI) were monitored. A transcutaneous carbon dioxide (TcCO2) monitor was attached to the right side of the chest instead of end-tidal carbon dioxide monitoring [
The patients’ records were analyzed in terms of the age at which the LM was diagnosed, birth history, sex, symptoms, symptom onset, type according to Olney’s classification, weight, and comorbid conditions. The feasibility of the STRIVE Hi anesthetic technique was evaluated according to the operation time, requirement for rescue oxygenation, and complications. Surgical outcomes, including resolution of symptoms, weight change, and complications, were also analyzed in patients who had undergone the operation. Weight percentile was analyzed using Wilcoxon’s signed-rank test with IBM SPSS ver. 22.0 (IBM Corp., Armonk, NY, USA).
A total of 29 LM patients were included in the study. The patients’ characteristics are summarized in
A total of 17 children (58.6%) underwent microlaryngobronchoscopy, 15 of whom continued to undergo supraglottoplasty under STRIVE Hi anesthesia (
The average age at the operation using the STRIVE Hi technique was 6 months (standard deviation [SD], 5.9 months; range, 1–20 months). Twelve patients (70.6%) completed the diagnostic procedure and surgical intervention without desaturation events (
As the larynx could swell immediately after surgery, all patients were routinely administered epinephrine and inhaled salbutamol via a nebulizer. After supraglottoplasty, a high-flow nasal cannula was used in four patients (4/15, 28.6%) and eight patients (8/15, 57.1%) were monitored in the intensive care unit postoperatively. All patients were transferred to the general ward within 24 hours.
Because the most of the patients were admitted to Department of Pediatrics, daily follow-up of symptoms was possible for 1 or 2 weeks after the operation. Symptoms usually improved on postoperative day 1 or 2 after the mucosal edema subsided. Symptom improvement was observed in 14 (93.3%) of the 15 children who underwent supraglottoplasty. Weight percentile changes were analyzed for 11 children for whom data were available, and the weight percentile was found to increase significantly postoperatively (Wilcoxon’s signed-rank test,
Only one patient showed aggravated inspiratory stridor and suprasternal retraction after supraglottoplasty. This patient had multiple brain anomalies (global developmental delay secondary to hypoxic ischemic encephalopathy, bilateral brain infarcts, microcephaly, seizure) and SAL (glossoptosis), which aggravated symptoms after supraglottoplasty. The surgeon determined that tracheostomy was necessary based on observations of the patient’s respiratory pattern and airway dynamics under STRIVE Hi anesthesia.
Patients with LM who were referred to or detected at the authors’ tertiary hospital included a higher proportion of type II and III cases. Most had one or multiple comorbidities and airway lesions. For LM patients, the STRIVE Hi technique may be useful and feasible for both microlaryngobronchoscopy and supraglottoplasty. In this study, 70.6% of patients (12/17) underwent microlaryngobronchoscopy with or without supraglottoplasty under the STRIVE Hi technique without any support from other anesthetic types of oxygen supply. The STRIVE Hi technique may have the potential for failure in patients with multiple comorbidities, particularly SAL.
The clinical characteristics of the patients in our study showed discrepancies from previous research. Inspiratory stridor in patients with LM is typically present during the first 2–4 weeks of life, and worsens with feeding, crying, placement in the supine position, and agitation [
The proportion of cases undergoing surgical treatment in our study was higher than that reported in previous studies because we had a higher proportion of patients with comorbidities and type II/III LM according to Onley’s classification. In previous studies, the rates of associated syndromes were 8%–20%, neurological disorders were 20%–45%, cardiac diseases were ~10%, and SAL were 7.5%–64% [
There are six possible anesthetic methods that can supply adequate oxygen during airway management: spontaneous breathing; positive pressure ventilation via an endotracheal tube; jet ventilation; apneic oxygenation using humidified high-flow nasal oxygen delivery systems or intermittent ventilation; crossfield ventilation; and extracorporeal membrane oxygenation (ECMO)/cardiopulmonary bypass (CPB) [
During the operation using the STRIVE Hi technique, temperature and humidity were maintained uniformly for all patients at levels that were high enough to prevent feelings of dryness in the nasal cavity of patients and to promote tolerance for the high-flow rate [
LM is suspected based on a typical clinical history, but the diagnosis is confirmed by a flexible fiberoptic exam in conscious patients [
The success rate of supraglottoplasty is approximately 94%, and it has a low complication rate. In this study, using the STRIVE Hi technique, 93.3% (14/15) of patients who underwent supraglottoplasty showed symptom improvement without severe complications. Children with LM are at significant risk for insufficient weight gain due to an increased workload while breathing and increased energy expenditure [
Patients with LM referred to our tertiary hospital had higher comorbidity rates than previously reported. Supraglottoplasty is a safe and effective treatment for most cases of severe LM. The STRIVE Hi technique ensures that the surgeon has an appropriate view for accurate diagnosis and ease of operation, and enables evaluation of the immediate postoperative respiratory status and results. Type III LM patients with micrognathia or glossoptosis may have a higher likelihood of requiring rescue oxygenation during the STRIVE Hi technique, while the presence of multiple comorbidities seemed to have no effect on the surgical success of supraglottoplasty.
▪ We analyzed the feasibility of the spontaneous respiration using intravenous anesthesia and high-flow nasal oxygen (STRIVE Hi) technique for the surgical management of laryngomalacia (LM).
▪ A relatively high proportion of LM patients in this study had multiple comorbidities.
▪ Approximately 73% of patients (13/17) did not need rescue oxygenation during the STRIVE Hi technique, and most of them (93.3%) showed symptom improvement without any complications.
▪ Type III LM patients with micrognathia or glossoptosis may have a higher risk of requiring rescue oxygenation during the STRIVE Hi technique.
No potential conflict of interest relevant to this article was reported.
This research was supported by the Bio & Medical Technology Development Program of the National Research Foundation (NRF) funded by the Korean government (MSIT) (No. 2019M3A9H1103617). Also, This research was supported by a grant of the Korea Health Technology R&D Project through the Korea Health Industry Development Institute (KHIDI), funded by the Ministry of Health & Welfare, Republic of Korea (grant number: HI14C1277).
Supraglottoplasty techniques for each type of laryngomalacia. (A) Type I, excision of short and redundant aryepiglottic fold. (B) Type II, lateral partial epiglottectomy in addition to the procedure used for type I. (C) Type III, excision of short aryepiglottic fold with epiglottopexy of after laser vaporization of epiglottis.
Flowchart for anesthesia maintenance and events.
Weight percentile change after surgery. Patients with supraglottoplasty showed significant changes in weight percentile (
Clinical characteristics of the patients
Variable | Number (%) | ||
---|---|---|---|
Sex (female:male) | 20 (68.9):9 (31.1) | ||
Type | |||
I | 13 (44.8) | ||
II | 10 (34.5) | ||
III | 6 (20.7) | ||
Age of onset | |||
At birth | 13 (44.8) | ||
>1 mo | 4 (13.8) | ||
>2 mo | 1 (0.3) | ||
Unknown | 11 (37.9) | ||
Symptom | |||
Respiratory symptom | |||
Stridor | 29 (100) | ||
Dyspnea with chest retraction | 16 (55.2) | ||
Stridor worsening with upper respiratory infection or when crying, excited | 6 (20.7) | ||
Cyanosis, tachypnea | 4 (13.8) | ||
Feeding symptom | |||
Small feeding amount, dysphagia due to respiratory distress | 12 (41.4) | ||
Tube feeding (nasogastric or gastrostomy tube) | 9 (31.0) | ||
Vomiting when feeding | 7 (24.1) | ||
Aspiration | 6 (20.7) | ||
Sleeping symptom | |||
Snoring, apnea | 6 (20.7) |
Associated comorbidities
Associated comorbidity | Number (%) | |
---|---|---|
Congenital anomaly/syndrome/genetic disorder | ||
Pierre Robin sequence | 1 (3.4) | |
Down syndrome | 1 (3.4) | |
Dandy-Walker (inversus) syndrome | 1 (3.4) | |
Trisomy 9 | 1 (3.4) | |
Cri du Chat variant | 1 (3.4) | |
Mobius syndrome | 1 (3.4) | |
Neurological disease | ||
Seizure | 4 (13.8) | |
Developmental delay |
4 (13.8) | |
Microcephaly, plagiocephaly |
3 (10.3) | |
Hypoxic ischemic encephalopathy | 3 (10.3) | |
Congenital hypotonia | 3 (10.3) | |
Others |
2 (6.9) | |
Cardiac disease | ||
ASD | 9 (31.0) | |
VSD | 4 (13.8) | |
PDA | 2 (6.9) | |
TOF | 2 (6.9) | |
TR | 1 (3.4) | |
PFO | 1 (3.4) | |
CMP | 1 (3.4) | |
Synchronous airway lesion | ||
Micrognathia, retrognathia | 3 (10.3) | |
Subglottic stenosis | 3 (10.3) | |
Glossoptosis | 2 (6.9) | |
Tracheomalacia, bronchomalacia | 2 (6.9) | |
Tongue base or vallecular cyst | 2 (6.9) | |
Vocal fold palsy | 2 (6.9) | |
Cleft palate | 2 (6.9) | |
Musculoskeletal | ||
Developmental dysplasia of the hip | 2 (6.9) | |
Kyphoscoliosis, T-spine | 1 (3.4) | |
A cyst in the filum terminale | 1 (3.4) | |
Partial agenesis of orbicularis oris muscle | 1 (3.4) | |
Ophthalmologic | ||
Retinal disorder | 1 (3.4) | |
Unilateral esotropia with secondary amblyopia and bilateral optic neuropathy | 1 (3.4) | |
Kidney | ||
Hydronephrosis | 3 (10.3) | |
Others | ||
Mondini dysplasia, narrow BCNC (hearing loss) | 1 (3.4) | |
Neonatal hyperbilirubinemia | 4 (13.8) | |
Disseminated intravascular coagulation, portal vein thrombosis | 1 (3.4) | |
Neutropenia, aPTT prolongation | 1 (3.4) | |
BPD, RDS (hyaline membrane disease) | 3 (10.3) |
ASD, atrial septal defect; VSD, ventricular septal defect; PDA, patent ductus arteriosus; TOF, tetralogy of Fallot; TR, tricuspid regurgitation; PFO, patent foramen ovale; CMP, cardiomyopathy; BCNC, bony cochlear nerve canal; aPTT, activated partial thromboplastin time; BPD, bronchopulmonary dysplasia; RDS, respiratory distress syndrome.
Language delay (n=1)+global developmental delay (n=3).
Plagiocephaly: microcephaly with simplified gyral pattern (n=1).
Cerebral infarct (n=1), brain cyst (n=1).
Perioperative characteristics of the patients who underwent surgical intervention
No. | Sex | Age (mo) | Type | Comorbidity | Simultaneous airway lesion | Operation | Operation time (min) |
Rescue oxygenation |
---|---|---|---|---|---|---|---|---|
1 | M | 3.1 | I | - | - | Microlaryngobronchoscopy+sup raglottoplasty | 35 | - |
2 | F | 9.3 | I | N/S/O | Glossoptosis | Microlaryngobronchoscopy+sup raglottoplasty+tracheostomy |
55 | - |
3 | F | 2.6 | I | G/N/C/S | uVFP, tracheomalacia, bronchomalacia | Microlaryngobronchoscopy |
30 | - |
4 | F | 4.1 | I | G/C/S/R | Glossoptosis | Microlaryngobronchoscopy+sup raglottoplasty | 145 | Orotracheal intubation |
5 | F | 3.4 | II | G/N/S/ | SGS, grade I | Microlaryngobronchoscopy+sup raglottoplasty | 30 | - |
6 | F | 3.3 | II | C/S/O | SGS, grade II | Microlaryngobronchoscopy+sup raglottoplasty | 66 | - |
7 | F | 3.9 | II | O | - | Microlaryngobronchoscopy+sup raglottoplasty | 50 | - |
8 | M | 2.9 | II | M/O | - | Microlaryngobronchoscopy+sup raglottoplasty | 60 | - |
9 | M | 4.1 | II | N/C/O | - | Microlaryngobronchoscopy+sup raglottoplasty | 75 | - |
10 | F | 7.2 | II | C/O | - | Microlaryngobronchoscopy+sup raglottoplasty | 70 | - |
11 | F | 15.2 | II | G/N/C/S | Vallecular cyst, SGS, grade II | Microlaryngobronchoscopy+sup raglottoplasty+vallecular cyst laser excision | 60 | - |
12 | M | 19.9 | II | N/C/R | - | Microlaryngobronchoscopy+sup raglottoplasty | 75 | - |
13 | F | 2.5 | III | C | - | Microlaryngobronchoscopy+sup raglottoplasty | 140 | - |
14 | F | 19.0 | III | N | - | Microlaryngobronchoscopy+sup raglottoplasty | 15 | Orotracheal intubation (due to muscle relaxant application for severe trismus) |
15 | F | 1.7 | III | G/C/S | Micrognathia, retrognathia, cleft palate, bronchomalacia | Microlaryngobronchoscopy | 60 | Intermittent mask bagging |
16 | F | 3.4 | III | C/S/O | Micrognathia, tongue base cyst | Microlaryngobronchoscopy+sup raglottoplasty+tongue base cyst excision | 35 | Orotracheal intubation |
17 | M | 1.9 | III | S | Micrognathia, glossoptosis, tongue base cyst | Microlaryngobronchoscopy+sup raglottoplasty+tongue base cyst excision | 80 | Orotracheal intubation |
N, neurological disease; S, synchronous airway lesion; O, ophthalmological; G, genetic disorders; C, cardiac disease; R, renal; O, others; M, musculoskeletal; uVFP, unilateral vocal fold palsy; SGS, subglottic stenosis.
Operation time indicates the time interval for maintenance of anesthesia under the STRIVE Hi technique.
As chest retraction was not alleviated after supraglottoplasty, the surgeon decided to perform tracheostomy after conversion to orotracheal intubation. There was no need for rescue oxygenation during supraglottoplasty.
Cases with planned tracheostomy.