Long term Follow Up of Severe Laryngomalacia Patients Following CO₂ LASER Supraglottoplasty

Abstract

Laryngomalacia is the most common cause of stridor. It is believed to be due to delayed development of the supraglottic structures. On the basis of presentation, it has been divided into 3 grades. Management is dependent upon the grades: Mild and moderate laryngomalacia are managed conservatively, while CO₂ LASER supraglottoplasty is the surgical management of choice for severe disease. In this study we evaluated the outcomes of supraglottopasty in long term follow up. It was a retrospective study which included patients with severe laryngomalacia who have undergone supraglottoplasty for the dates from July 2013 to July 2018. Weight and height of the patients were taken during the follow up visit after one year and have been compared with that of the normal children of comparable age using the pediatrics growth charts. Follow up was done by telephonic conversation to evaluate the status of other symptoms associated with laryngomalacia. Total of 44 patients were included in the study, 47.7% and 52.3% females and males respectively. Weight for age, weight for height and height for age were normal in 80.9%, 80.9% and 76.1% of patients respectively after supraglottoplasty. Of the patients studied, stridor was resolved in 80.9%, early tiredness during play was resolved in 43.2%, swallowing was normal in 85.7% and there was no aspiration in 90.5%. It can be concluded that patients with severe laryngomalacia improved with respect to airway symptoms, as well as, weight and height on long term follow up after CO₂ LASER supraglottoplasty. It is important to evaluate the general status of the patients as a whole to truly assess the success of the surgery in addition to the airway symptoms.

Introduction

Laryngomalacia is defined as the delay in the development of the supraglottic structures causing their collapse on inspiration [1]. It is the most common cause of stridor in the newborn and may present with failure to thrive besides stridor [1–7]. On the basis of the presenting features laryngomalacia is divided into mild, moderate and severe grade, as shown in Table 1 [6].

Table 1.

Grades of laryngomalacia

Grades of laryngomalacia	Presenting signs and symptoms
Mild	Inconsequential inspiratory stridor without any other complaint
Moderate	Stridor along with regurgitation, coughing and choking episodes with feeding
Severe	Stridor along with failure to thrive, feeding problems, aspiration, apnea, hypoxia, recurrent cyanosis, cor-pulmonale, and other end organ damage

Surgery is the treatment of choice for severe laryngomalacia [2–5]. After surgery, patients are observed in intensive care unit, and once stable, are discharged with the advice for proper follow up [2, 8, 9, 9–13]. The success of treatment is not only dependent on the resolution of the stridor, but we also have to evaluate the general condition and associated symptoms as described above. Weight gain and proper feeding are the most important criteria for good treatment outcome [1]. In this study, we have evaluated the outcomes of CO₂ LASER supraglottoplasty (reffered as supraglottoplasty from hereon) performed for severe laryngomalacia.

Methods and Materials

This was a retrospective study performed to assess the long-term outcomes of supraglottoplasty for severe laryngomalacia patients. The study was carried out in a Laryngology Department, Deenanath Mangeshkar Hospital and Research Center, Pune, India. Approval was granted by the Institutional Ethics Committee of Deenanath Mangeshkar Hospital and Research center. The data was retrieved from the hospital software for dates from July 2013 to July 2018. Data were included for all patients who underwent surgery for severe laryngomalacia.

The laryngomalacia patients were followed up for one year after surgery. The first follow up was done six weeks after the surgery, second done six months after the first follow up, and the third done six months after the second follow up. If the patients did not have any problems during the third follow up, they were then called whenever required. During each follow up, a detailed systemic, ENT examination and nasopharyngolaryngoscopy was done. Weight and height were recorded during each follow up visit.

We collected the details of the patient like demographic data, gender, age at the presentation, chief complaint at presentation, any comorbidities, any synchronous airway lesions (SAL) and the final diagnosis from the hospital software. From the same, we took the weight and height of the patients during follow up, after a minimum of one year after surgery. The weight for height, weight for age and height for age were compared with that of normal children of comparable age [14, 15]. These findings were then analyzed as normal or less than normal for every patient.

For follow up, a questionnaire was made after thorough discussion in the department. The questionnaire included evaluation of symptoms like presence or absence of stridor, swallowing difficulties and aspiration. The patients were subsequently followed up with a telephonic interview. Verbal consent was taken for every patient. Conversation with the parents of the patient was given priority rather than other family members. All the calls were made by a single speaker using the local language. To address the confounding effect, we divided the patients into 4 groups according to presence and absence of SAL and medical comorbidities. The first group consisted of the patients with SAL only, second group consisted of the patients with medical comorbidities only, the third consisted of the patients with both, SAL and medical comorbidities and the fourth consisted of patients without any SAL and medical comorbidities. The findings for each of groups were analyzed and interpreted separately.

Results

There were 44 patients included in the study. Out of them 21 (47.7%) were males and 23 (52.3%) were females. The mean age of presentation was 71.6 ± 16.8 days (range 15–390 days). Mean duration of the follow up for taking weight and height was 13.5 ± 3.2 months after the surgery, while mean duration of conducting the telephonic interview was 24.6 ± 6.5 months after the surgery. SAL along with laryngomalacia was present in 16/44 (36.4%) patients, and in 9/44 (20.4%) patients, there was some form of medical comorbidity present.

Follow up parameters were recorded for the various groups of patients. We divided the patients into 4 groups as described in methodology. In the first group, there were 14/44 (31.8%) patients with only SAL, in the second group, there were 7/44 (15.9%) patients who had only medical comorbidities, in the third group, there were 2/44 (4.5%) patients with both, medical comorbidities and SAL, and lastly, in the fourth group, there were 21/44 (47.7%) patients who neither had SAL nor any medical comorbidities. Distribution of patients according to their height and weight parameters is shown in Table 2.

Table 2.

Distribution of patients according to height and weight findings

Parameters	Findings	Group I (n = 14)	Group II (n = 7)	Group III (n = 2)	Group IV (n = 21)
Weight for age	Normal	9/14 (64.3%)	0	0	17/21 (80.9%)
	Less	5/14 (35.7%)	7/7 (100%)	2/2 (100%)	4/21 (19.1%)
Weight for height	Normal	9/14 (64.3%)	0	0	17/21 (80.9%)
	Less	5/14 (35.7%)	7/7 (100%)	2/2 (100%)	4/21 (19.1%)
Height for age	Normal	9/14 (64.3%)	0	0	16/21 (76.1%)
	Less	5/14 (35.7%)	7/7 (100%)	2/2 (100%)	5/21 (23.8%)

Note: here less means less than normal value

In group I, the weight for age, weight for height and height for age were normal in 64.3% of the patients. Groups II and III had less weight for age, weight for height and height for age for all the patients. In group IV, the weight for age, weight for height and height for age were normal in 80.9%, 80.9% and 76.1% of patients respectively. The data from the questionnaire of each and every patient were analyzed and recorded as shown in Table 3.

Table 3.

Distribution of patients on the basis of presence of various symptoms

Symptoms	Findings	Group I (n = 14)	Group II (n = 7)	Group III (n = 2)	Group IV (n = 21)
Stridor	Present	8/14 (57%)	2/7 (28.4%)	1/2 (50%)	4/21 (19.04%)
Gets tired early while playing	Present	9/14 (64.3%)	7/7 (100%)	2/2 (100%)	7/21 (33.3%)
Swallowing	Normal	10/14 (71.5%)	4/7 (57.2%)	1/2 (50%)	18/21 (85.7%)
Aspiration	Present	2/14 (14.3%)	3/7 (42.8%)	1/2 (50%)	2/21 (9.5%)

The presence of these symptoms was further subdivided into subheadings as described in the following paragraph. In patients with stridor in group I, 42.8% had it during activities while 7.1% patients each, had it during daytime and nighttime respectively. In group II, 14.2% patients had stridor during daytime and nighttime respectively. In group III, there was single patient with stridor and it was present during daytime. In group IV, 14% had stridor during activities and 5% had it during nighttime. For this study “daytime” indicated the resting period during the day (i.e. patients were not playing or doing anything).

In patients with swallowing difficulty in group I, 21.4% had difficulty in swallowing liquids and 7.1% had difficulty in swallowing liquids and solids both. In group II, 28.5% had difficulty for liquids and 14.3% had difficulty for liquids and solids both. In group III, there was single patient with difficulty in swallowing liquids. Lastly in group IV, 9.5% patients had difficulty in swallowing liquids and 4.8% had difficulty in swallowing liquids and solids both. In patients with aspiration, all of them had aspiration for liquids only; none of the patients had aspiration for solids.

Discussion

Laryngomalacia is the most common congenital anomaly of the larynx. There are various management protocols mentioned in the literature for this condition. At our institution we conservatively manage mild and moderate cases, and maintain a regular follow up. During follow up, we look for resolution of stridor and other symptoms. In case of severe disease, and in those with mild and moderate disease which did not improve after observation, surgery is performed. A similar management protocol has been mentioned in other studies [10–12, 16–18]. Supraglottoplasty is the surgery done with primary aim of improving the airway. However, the success of the surgery not only depends on adequacy of airway but also on improvement in the general status of the patients. So various predictors of good general status have to be assessed in order to evaluate the success of the surgical procedure. In this study, we evaluated the height and weight, presence or absence of stridor, tiredness during play, swallowing status and presence or absence of aspiration in patients after supraglottoplasty. To the best of our knowledge, there is no other study which has assessed all of these parameters.

In the study, the height and weight of the patients were taken at a minimum of 1-year post surgery. We assumed one year to be a sufficient time period for gaining weight after the surgery, if the airway symptoms were relieved. Studies by Meier et al. [19] and Josephine A. Czechowicz et al. [20] have measured weight after one year of surgery and three months after surgery respectively. From these weight and height parameters, we compared weight for age, weight for height and height for age with that of the normal children of comparable age from the pediatric height and weight chart [14, 15]. We felt that comparing with normal children of comparable age, we could get a good idea about improvement in failure to thrive. Similar pattern of weight comparison was done in the study by Meier et al. [19], but they compared growth curves of the laryngomalacia patients managed by conservative approach with those managed by surgery. In this study, there was an improvement in weight and height in patients having laryngomalacia alone, rather than in patients having SAL or medical comorbidities along with laryngomalacia. Presence of SAL may lead to persistence of difficulty in breathing even after supraglottoplasty and may have caused decreased weight gain. Similarly, if the patient has medical comorbidities, the weight gain would be hampered. Studies by Meier et al. [19] and Whymark et al. [11] showed an improvement in weight after the supraglottoplasty; however they did not consider height as a parameter. We included height as we felt that it was an important parameter, as most of the times, failure to thrive may result in stunted growth. In addition, height provides a baseline to compare weight besides age. Czechowicz et al. [20] in their study also measured height along with weight and found significant improvement after surgery. Study by Senders et al. [12] showed significant improvement in weight of the patients without SAL compared to the patients with SAL. No improvement in failure to thrive or even worsening was shown in patients with medical comorbidities in other studies also [2, 12, 18, 21].It can be seen from our study that weight and height gain of the patients are not primarily associated with resolution of laryngomalacia alone. Medical comorbidities along with SAL also have a role to play.

We found that there was resolution in the above-mentioned respiratory symptoms, more in the patients with laryngomalacia alone, than in the patients having associated airway anomalies or medical comorbidities or both. C.W. Senders et al. [12] in their study showed that in patients without SAL there was an immediate resolution of respiratory symptoms in approximately 80% to 100% within a week of surgery while with SAL, the resolution of symptoms was much lower, approximately 15% resolving immediately after surgery, 30% within a week, 50% within a month and 57% within 6 months. Van der Heijden et al. [1] showed a complete improvement of all symptoms in patients with supraglottoplasty within 6 weeks. However, 3 patients improved after 31, 57 and 58 weeks. Kuo-Sheng et al. [2] showed improvement in all of the symptoms in 82.6% of patients, with those having no improvement being the ones with some form of medical comorbidities. Along with other respiratory symptoms, we enquired about the tiredness during playing in comparison to their friends or siblings, as this was a frequently encountered symptom in our clinical practice. We couldn’t find any study assessing tiredness during playing. This data tells us about the adequacy of airway during increased demand. As expected, we found 56.8% of patients with early tiredness or difficulty in breathing while playing who were asymptomatic at rest.

For the presence of respiratory symptoms, we elaborated them on the basis of various subheadings or conditions. For patients with stridor postoperatively, we assessed whether it was more during activities, during the daytime or during the nighttime. Most of the patients (64.3%) had stridor during activities followed by nighttime and then daytime. Presence of stridor during activities could have been due to increased airway demand, as described previously. Stridor present only during the nighttime may be due to falling back of the soft tissues during sleep. Literature search did not reveal any study which has similarly elaborated upon these symptoms.

In regard to patients having difficulty during swallowing, we found that more patients were having difficulty in swallowing the liquids than the solids which could be attributed to some neurological cause. All the patients who complained of aspiration had aspiration with liquids only. Chun et al. [22] in their study have shown that there may be transient swallowing difficulty with complaints of aspiration in the immediate postoperative period following supraglottoplasty due to the surgical interference of the laryngopharyngeal complex. We followed up after a minimum duration of 1 year, assuming that this transient post-surgical affect would not be there. Thus, it would be reasonable to say that the swallowing difficulty and aspiration were not due to the surgical effect. Richter et al. [8] have shown in their study, a significant improvement in the swallowing and aspiration symptoms following supraglottoplasty. Studies by Schroeder et al. [23] and Eustaguio et al. [24] have shown increased frequency of aspiration and swallowing difficulty after supraglottoplasty in the early post-operative period. However, they do not report data on long term follow up. None of these studies have mentioned about swallowing and aspiration with respect to consistency of the food.

The main limitations in our study were the telephonic method of follow up, the inherent subjectivity or bias of parent-reported outcomes and the small sample size. It is of utmost importance to evaluate the outcome of supraglottoplasty by conducting a prospective study with a larger sample size. We also recommend a more detailed assessment of patient by following up with them in person at the hospital, for future studies.

Conclusion

From this study it can be concluded that patients with severe laryngomalacia improved with respect to airway symptoms, as well as, weight and height on long term follow up after supraglottoplasty. It is important to evaluate the general status of the patients as a whole to truly assess the success of the surgery in addition to the airway symptoms. Prospective studies with larger sample size and in person follow up methods are recommended for future studies for further clarity in the subject matter.

Compliance with ethical standards

Conflict of interest

The authors declare that they have no conflict of interest.