Recognizing the importance of adequate follow-up for hearing impairment in trisomy 18
Abbreviations
-
- AABR
-
- automated auditory brainstem response
-
- ABR
-
- auditory brainstem response
-
- IQR
-
- interquartile range
We read the article by Tamaki et al. (2023) with great interest. Notwithstanding the short-term outcomes of trisomy 18, which improved due to intensive care, including cardiac surgery (Tamaki et al., 2022), the comorbidities of trisomy 18 are yet to be fully investigated. Tamaki et al. (2023) demonstrated the characteristics of hearing impairment in trisomy 18 and emphasized its high proportion. We present data on hearing impairment and follow-up of patients with trisomy 18 at our hospital.
In this single-center retrospective cohort study, we aimed to describe the background characteristics of patients with trisomy 18 based on whether they underwent or did not undergo automated auditory brainstem response (AABR) screening. Moreover, we sought to describe the otolaryngological follow-up course of those who failed AABR. We identified 30 patients with trisomy 18 who were admitted to our neonatal intensive care unit (NICU) between April 2010 and July 2023, and investigated the characteristics, outcomes, screening, and follow-up status. We also described the data on the need for invasive or non-invasive positive ventilation at discharge, because it may influence whether hearing screening is performed, and the raw data of AABR and auditory brainstem response (ABR) results of the patients who failed AABR. We categorized patients with trisomy 18 into two groups according to whether they underwent hearing screening using the AABR, because the reasons for not performing AABR in patients with trisomy 18 have not been well-elucidated in previous studies. We used Fisher's exact test to compare categorical variables and the Kruskal–Wallis test to compare medians for continuous variables. Continuous variables were described as median and interquartile range (IQR). All statistical analyses were conducted using Stata/BE 18.0 (StataCorp, College Station, TX, USA).
Table 1 shows the patient characteristics and outcomes. All patients with trisomy 18 in our cohort had full trisomy 18. The median gestational age and birth weight were 38.2 (IQR: 36.7–40.3) weeks and 1833 (IQR: 1600–2103) g, respectively. All patients had congenital heart disease. Patients who underwent AABR had higher Apgar scores and lower in-hospital and 30-day mortality rates than those who did not undergo AABR. Abnormal AABR screening results were observed in 12 (75%) patients. Although three patients did not undergo AABR screening despite surviving to discharge, they required ventilation after tracheostomy or noninvasive positive pressure ventilation at discharge. Table 2 shows the results of hearing testing, otolaryngology follow-up, and patient management after discharge among the 12 patients who failed the AABR screening. Three patients had never undergone an ABR, and five patients never received follow-up with otolaryngology. Home respiratory devices were used in 75% of the patients. Only one child received hearing aids. The type of hearing loss was not identified in our cohort and imaging studies for hearing impairment were not conducted.
| All patients | AABR screening | |||
|---|---|---|---|---|
| + | – | |||
| n = 30 | n = 16 | n = 14 | p-Value | |
| Background characteristics | ||||
| Male | 9 (30) | 5 (31) | 4 (29) | 1.00 |
| Gestational age (weeks) | 38.2 (36.7–40.3) | 38.9 (37.6–40.1) | 37.3 (36.4–39.0) | 0.11 |
| Birth weight (g) | 1833 (1600–2103) | 1896 (1626–2257) | 1744 (1559–1995) | 0.41 |
| Caesarian section | 17 (57) | 9 (56) | 8 (57) | 1.00 |
| Apgar score 1 min | 4 (2–6) | 6 (3.5–6) | 2.5 (1–4) | 0.003 |
| Apgar score 5 min | 7 (5–8) | 7.5 (7–8) | 4 (5–7) | 0.012 |
| Congenital heart disease | 30 (100) | 16 (100) | 14 (100) | NA |
| ASD, CoA, VSD, PDA | 3 (10) | 2 (13) | 1 (7.1) | |
| ASD, DORV, MA, PDA | 2 (6.7) | 0 (0.0) | 2 (14) | |
| ASD, DORV, PDA | 2 (6.7) | 2 (13) | 0 (0.0) | |
| ASD, PDA, VSD | 16 (53) | 10 (63) | 6 (43) | |
| HLHS | 2 (6.7) | 0 (0.0) | 2 (14) | |
| Others | 5 (17) | 2 (13)a | 3 (21)b | |
| Esophageal atresia | 8 (27) | 3 (19) | 5 (36) | 0.42 |
| Treatment characteristics | ||||
| Received surgery | 12 (40) | 7 (44) | 5 (36) | 0.72 |
| Cardiovascular disease | 3 (10) | 2 (13) | 1 (7) | 1.00 |
| Digestive disease | 9 (30) | 5 (31) | 4 (29) | 1.00 |
| Tracheostomy | 3 (10) | 2 (13) | 1 (7) | 0.55 |
| Outcomes | ||||
| In-hospital mortality | 11 (37) | 0 (0.0) | 11 (79) | <0.001 |
| 30-day mortality | 6 (20) | 0 (0.0) | 6 (43) | 0.005 |
| Failed AABR screening | 12 (75) | NA | ||
- Note: Data are presented as n (%) or median (IQR).
- Abbreviations: AABR, automated auditory brainstem response; ASD, atrial septal defect; CoA, coarctation of aorta; DORV, double outlet right ventricle; HLHS, hypoplastic left heart syndrome; MA, mitral atresia; NA, not applicable; PDA, patent ductus arteriosus; VSD, ventricular septal defect.
- a Hypoplastic aortic arch, VSD, and PDA (1), interrupted aortic arch, ASD, and PDA (1).
- b Aortic atresia, PDA, and VSD (1), ASD, DORV, double aortic arch, HLHS, PDA, and pulmonary atresia (1), DORV and pulmonary stenosis (1).
| AABR testing | Ages at initial | ABR testing (dB) | Otolaryngology follow-up | Hearing aids | Home respiratory care | Age of death (days) | |||
|---|---|---|---|---|---|---|---|---|---|
| Case | Right | Left | AABR (days) | Right | Left | ||||
| 1 | Refer | Refer | NA | 50 | 60 | − | − | − | 368 |
| 2 | Pass | Refer | 122 | − | − | − | − | − | 329 |
| 3 | Pass | Refer | 56 | − | − | − | − | − | 208 |
| 4 | Refer | Refer | NA | − | − | − | − | HMV | 575 |
| 5 | Refer | Refer | 136 | 105S.O. | 105 | + | − | HMV | 372 |
| 6 | Refer | Pass | 52 | 85 | 85 | + | − | HOT | 375 |
| 7 | Refer | Pass | 112 | 105 | 85 | + (up to 3 years old) | − | HOT | 1449 |
| 8 | Refer | Refer | 91 | 105 | 85 | + | − | HOT | NA |
| 9 | Refer | Refer | 41 | 105 | 105 | − | − | HNPPV | 135 |
| 10 | Refer | Refer | 41 | 80 | 105S.O. | + (up to 6 months old) | − | HNPPV | Surviving on Day 784 |
| 11 | Pass | Refer | 35 | 35 | 105S.O. | + | − | HOT | Surviving on Day 300 |
| 12 | Refer | Refer | 64 | 70 | 90 | + | + (at 6 months) | HNPPV | Surviving on Day 267 |
- Abbreviations: AABR, automated auditory brainstem response; ABR, auditory brainstem response; HMV, home mechanical ventilation; HOT, home oxygen therapy; HNPPV, home noninvasive positive pressure ventilation; NA, not available; S.O., scale out.
In this study, we revealed a low otolaryngological follow-up percentage of patients with trisomy 18 in our cohort, which contradicts the results reported by Tamaki et al. (2023). The patients without AABR had a higher mortality than those with AABR. The surviving patients who did not undergo AABR screening received invasive or non-invasive positive pressure ventilation. Although there is no definite guideline for hearing screening and follow-up on trisomy 18 in our hospital, the patients in our NICU are usually required to receive AABR during hospitalization and all patients with hearing screening referrals are usually referred to otolaryngologists and undergo ABR testing. Therefore, the severity and the status of respiratory management may influence whether hearing screening is performed.
The patients in this study might have had more severe conditions than those in the study by Tamaki et al. (2023), because our hospital is a referral center for congenital heart disease surgery and all patients in our cohort had congenital heart disease. Previously, a recommendation for surveillance in trisomy 18 has been reported (Kepple et al., 2021). This recommendation states the importance of repeated hearing screenings in patients with trisomy 18 because screening is often difficult in these patients due to their small ear canal (Kepple et al., 2021). Decisions regarding repeat hearing tests in hearing follow-up in patients with trisomy 18 are left to the attending doctor in our institute. The establishment of follow-up guidelines within each hospital is crucial for hearing follow-up.
The high prevalence of hearing impairment in patients with trisomy 18 in this study was comparable to that reported in previous studies (Benson et al., 2023; Tamaki et al., 2023). However, the percentage of children receiving otolaryngology follow-up visits and hearing aid use in this study were lower than those reported by Tamaki et al. (2023). Because the majority of the patients used home respiratory devices in this study, difficulty in performing hearing tests may have contributed to the low rate of follow-up with otolaryngology. Additionally, studies on comorbidities of trisomy 18 are limited (Benson et al., 2023), because many previous studies of trisomy 18 have focused on mortality. However, children with trisomy 18 are capable of developing their language and communication skills and social–emotional domains (Bruns, 2015). Prolonged survival time in patients with trisomy 18 allows them to spend quality time with their families (Tamaki et al., 2022). Similarly, increased utilization of hearing evaluations and hearing aids may further enhance their lives and facilitate communication. Although Tamaki et al. (2023) revealed the effectiveness of hearing aids in trisomy 18, the necessity for adequate follow-up and intervention for hearing impairments in trisomy 18 may not be widely recognized by clinicians based on the results of our study. Our study has several limitations. First, we could not investigate the influence of parent and healthcare provider attitudes to hearing screening due to the retrospective study design. Second, we could not investigate the detailed information on the otolaryngology examination, such as physical examination and imaging studies, from the medical records. Further research regarding these aspects is also needed.
In conclusion, there was a notable prevalence of abnormal AABR screening results, and certain patients with such abnormalities lacked adequate follow-up. The prevalence of hearing impairment and the effectiveness of hearing aids in patients with trisomy 18 should be determined. Clinicians should not forget to follow-up on hearing impairments in patients with trisomy 18.
AUTHOR CONTRIBUTIONS
Hiroki Kitaoka conceptualized the research, acquisition, analysis of the clinical data, and drafted the initial letter. Yoshihiko Shitara, Atsushi Ito, and Kohei Kashima conceptualized the research, interpreted the clinical data, and revised the letter. Motohiro Kato and Naoto Takahashi coordinated and supervised data collection, and critically reviewed the letter.
ACKNOWLEDGMENTS
The authors have nothing to report.
FUNDING INFORMATION
The authors have no specific grants from public, commercial, or not-for-profit funding agencies.
CONFLICT OF INTEREST STATEMENT
The authors declare no conflicts of interest.
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DATA AVAILABILITY STATEMENT
The data that support the findings of this study are available from the corresponding author upon reasonable request.
