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Carbon dioxide laser versus cold-steel supraglottoplasty: A comparison of post-operative outcomes
International Journal of Pediatric Otorhinolaryngology 130 (2020) 109843
Contents lists available at ScienceDirect
International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Carbon dioxide laser versus cold-steel supraglottoplasty: A comparison of post-operative outcomes
T
Jeffrey C. Yeunga,b,∗, Syed O. Alib, Mallory G. McKeonb, Samantha Grenierb, Kosuke Kawaib, Reza Rahbarb,c, Karen F. Wattersb,c Department of Otolaryngology – Head & Neck Surgery, McGill University, Canada Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, USA c Department of Otology and Laryngology, Harvard Medical School, USA a
b
A R T I C LE I N FO
A B S T R A C T
Keywords: Supraglottoplasty Pediatric CO2 laser Post-operative outcomes
Objective: Supraglottoplasty is the mainstay of surgical treatment for laryngomalacia, and is commonly performed via two methods: cold steel or carbon dioxide (CO2) laser. The degree of post-operative monitoring following supraglottoplasty varies, both within and between institutions. The aim of this study was to compare the post-operative monitoring and interventions required by patients undergoing cold-steel versus CO2 laser supraglottoplasty. Design: Retrospective cohort of pediatric patients (age < 18 years) undergoing supraglottoplasty at a tertiary care pediatric hospital. The primary exposure was the surgical instrument(s) used during supraglottoplasty. The primary outcome was prolonged intensive care unit (ICU)-stay (defined as > 24 h). Results: 155 cases were eligible for inclusion. Fifty-eight (37.4%) patients had a comorbid condition. Common indications for surgery included feeding difficulty (56.1%), severe respiratory distress (33.5%), and obstructive sleep apnea (25.2%). CO2 laser was employed in 49 cases and cold-steel in 106 cases. Prolonged ICU-stay (> 24 h) was observed in 14 CO2 laser cases (28.6%) and 11 cold-steel cases (10.4%) (adjusted OR 3.42; 95% CI 1.43, 8.33). CO2 laser cases were more likely to require post-operative intubation, non-invasive positive pressure ventilation, and nebulized racemic epinephrine. Concomitant neurological condition was associated with an increased risk of prolonged ICU-stay, while extent of surgery and age were not. Conclusions: CO2 laser supraglottoplasty is associated with an increased risk of prolonged ICU-stay and need for ICU-level airway intervention, compared to the cold-steel technique. While this association should not be misconstrued as a causal relationship, the current study demonstrates that specific surgical factors may influence the patient monitoring requirements following supraglottoplasty, particularly the choice of instrument and the extent of surgery.
1. Introduction Laryngomalacia is the most common cause of infant stridor, and a common reason for Otolaryngology referral. While the majority will resolve spontaneously, up to 20% of patients with laryngomalacia require surgical management [1]. The mainstay of surgical therapy is supraglottoplasty, a term that encompasses the removal of excess/redundant arytenoid mucosa, division of the aryepiglottic (AE) folds, epiglottopexy or a combination of these. Supraglottoplasty may be performed using several instruments, most commonly with cold-steel dissection or carbon dioxide (CO2) laser [2]. Both surgical instruments produce equivalent post-operative outcomes in the long-term [3,4]. The
∗
decision on the extent of surgery is generally made at the discretion of the surgeon and is based on clinical endoscopic examination as well as the operative examination. The post-operative monitoring for patients varies both within and between institutions. Traditionally for airway surgery, routine postoperative monitoring in an intensive-care unit (ICU) has been standard of practice, and over half of otolaryngologists surveyed (53%) through the Society for Ear Nose and Throat Advances in Children adhere to this practice [2]. However, the percentage of patients needing ICU-level intervention following supraglottoplasty (i.e. intubation, non-invasive positive pressure ventilation [NIPPV], high-flow oxygen) has reported to be as low as 5% and as high as 63% [5–9]. Recent reports have
Corresponding author. Department of Otolaryngology – Head & Neck Surgery, McGill University Health Center, Montreal, Canada. E-mail address: jeff[email protected] (J.C. Yeung).
https://doi.org/10.1016/j.ijporl.2019.109843 Received 28 August 2019; Received in revised form 17 December 2019; Accepted 17 December 2019 Available online 24 December 2019 0165-5876/ © 2019 Published by Elsevier B.V.
International Journal of Pediatric Otorhinolaryngology 130 (2020) 109843
J.C. Yeung, et al.
advocated for close peri-operative monitoring outside of the ICU for several hours to better allocate ICU resources [7,9]. Determining which patients require ICU-level airway intervention post-operatively, as well as factors influencing this decision, are essential in providing safe and efficient care to this patient population. The aim of this study was to determine whether use of the CO2 laser affects the early post-operative outcomes in patients undergoing supraglottoplasty.
Table 1 Patient characteristics.
Primary supraglottoplasty Male History of prematurity Patients with at least one comorbidity Cardiac Neurological Pulmonary Transplant/immunological Syndromic Other Presenting Symptoms Stridor Reflux Cyanosis Apnea Failure to thrive Indication for Surgery Failure to thrive Obstructive sleep apnea Severe respiratory distress Feeding difficulty Other
2. Methods A retrospective cohort study was performed following institutional research ethics approval. The study took place in a tertiary care pediatric hospital setting and studied patients with laryngomalacia undergoing supraglottoplasty between January 2009 and December 2016. This cohort represented surgeries performed by all attending physicians employed during the study period and the choice of instrument was based on individual surgeon-preference. Patients diagnosed with laryngomalacia during the study period were identified using International Statistical Classification of Diseases and Related Health Problems Codes (ICD-10 Q31.5 and/or ICD-9-CM 748.3). These were cross-referenced with patients who underwent supraglottoplasty using Current Procedural Terminology Codes (31599, 31541, and 31588). Patient characteristics obtained from the medical record included demographic information, presenting symptoms, comorbid conditions, indication(s) for surgery, physical findings, pertinent diagnostic tests, surgery date, operative records, anesthetic records and results of investigative testing. All patients (age < 18) undergoing supraglottoplasty were eligible for inclusion. Exclusion criteria consisted of patients undergoing concomitant airway surgery, revision surgery, and those who required ICU-stay pre-operatively. All data was entered into a REDCap Database (Vanderbilt University, Nashville TN). The primary exposure of interest was the surgical instrument used for supraglottoplasty. Patients were assigned to the cold-steel group if their entire surgery was performed using only cold-steel microlaryngeal instruments. Patients were assigned to the CO2 laser group if any portion of the supraglottoplasty was performed using CO2 laser. Operative records were reviewed to determine the extent of supraglottoplasty (division of AE folds, resection of arytenoid mucosa, epiglottopexy or combination) as well as the instrument(s) utilized (cold-steel, CO2 laser, powered instrument or combination). The primary outcome of interest was prolonged ICU-stay, as defined as > 24 h. Secondary outcomes of interest were ICU-level airway interventions, including use of nebulized racemic epinephrine positivepressure ventilation, NIPPV, and endotracheal intubation. Risk adjustment was carried out for young patients (age < 6 months), history of prematurity, history of comorbid condition, duration of surgery, and extent of surgery (division of AE folds, arytenoid mucosa resection, or both). To compare the characteristics of patients who underwent cold-steel vs. CO2 laser supraglottoplasty, we used Chi-square or Fisher's exact test for categorical variables and Wilcoxon rank sum test for continuous variables. A logistic regression model was used to examine risk factors associated with a prolonged ICU-stay. Odds ratio (OR) and 95% confidence interval (CI) were estimated. Any potential risk factors with p < 0.20 in univariate analyses were considered as candidates for the multivariable analyses. The final multivariable regression model was built using backward selection procedure with p < 0.05 as the retention criteria. Statistical analyses were conducted using SAS version 9.4 (SAS Institute, Cary, NC).
Total
CO2 laser
Cold-steel
155 96 (61.9%) 25 (16.1%) 58 (37.4%) 12 (7.7%) 24 (15.5%) 11 (7.1%) 1 (0.7%) 18 (11.6%) 19 (12.3%)
49 29 (59.2%) 8 (16.3%) 21 (42.9%) 7 (14.3%) 9 (18.4%) 5 (10.2%) 0 (0%) 6 (12.2%) 9 (18.4%)
106 67 (63.2%) 17 (16.0%) 37 (34.9%) 5 (4.7%) 15 (14.2%) 6 (5.7%) 1 (0.9%) 12 (11.3%) 10 (9.4%)
134 (86.5%) 56 (36.1%) 7 (4.5%) 40 (25.8%) 18 (11.6%)
39 (79.6%) 17 (34.7%) 2 (4.0%) 18 (36.7%) 5 (10.2%)
95 (89.6%) 39 (36.8%) 5 (4.7%) 22 (20.8%) 13 (12.3%)
23 39 52 87 31
9 (18.4%) 17 (34.7%) 19 (38.8%) 24 (49.0%) 13 (26.5%)
14 22 33 63 18
(14.8%) (25.2%) (33.5%) (56.1%) (20.0%)
(13.2%) (20.8%) (31.1%) (59.4%) (17.0%)
supraglottoplasty during the study period. Forty-five were excluded: 2 due to incomplete medical records, 8 due to concomitant airway surgery, 33 due to pre-operative ICU-stay, and 2 patients were undergoing revision surgery. Further, 3 epiglottopexy patients were excluded. 155 eligible patients were included in the study. 3.2. Descriptive data Of 155 supraglottoplasties performed, 96 (61.9%) were male (Table 1). The median age at the time of surgery was 8 months (interquartile range [IQR] 3–22 months). Twenty-five (16.1%) patients had a history of prematurity (born at less than 37 weeks gestational age). The median gestational age of premature patients was 33 weeks (IQR 30–35 weeks). The most common presenting symptoms were stridor (86.5%), reflux (36.1%), apneic events (25.8%), and failure to thrive (11.6%). Fifty-eight (37.4%) patients had a comorbid condition, namely cardiac (7.7%), neurologic (15.5%), pulmonary (7.1%), and syndromes (11.6%). The most common indications for supraglottoplasty were feeding difficulty (56.1%), severe respiratory events (33.5%), and obstructive sleep apnea (25.2%). All patients undergoing surgery were given a single dose of preoperative corticosteroids (intravenous dexamethasone 0.5 mg/kg). All supraglottoplasties were immediately preceded by direct laryngoscopy and bronchoscopy. The most common secondary airway lesions identified were laryngeal cleft (16), tracheomalacia (6), subglottic stenosis (4), and vocal cord paralysis (1). Sixteen patients had other findings on bronchoscopy not classified as above, specifically 1) narrowing that was not classified as stenosis; 2) submucosal mass, 3) blunted carina, 4) edematous distal trachea, and/ or 5) deep interarytenoid groove. Of 155 supraglottoplasties performed, 106 (67.1%) of the supraglottoplasties were performed with cold-steel technique and 49 (31.0%) with the CO2 laser. One hundred five (67.7%) patients underwent division of the AE folds alone, 15 (9.6%) underwent resection of the arytenoid mucosa alone, and 35 (22.6%) underwent a combination of both. The mean (SD) operative time was 55.8 (38.7) minutes. The extent of surgery is summarized in Table 2.
3. Results 3.3. Outcome Data 3.1. Participants Overall, 25 of 155 (16.1%) of patients required prolonged ICU-stay post-operatively. Of these patients, 7 (4.5%) required intubation, 16
203 patients were identified with laryngomalacia undergoing 2
International Journal of Pediatric Otorhinolaryngology 130 (2020) 109843
J.C. Yeung, et al.
unplanned ICU admission [3,7]. The current study was designed to determine if use of the CO2 laser during supraglottoplasty was associated with higher incidence of airway events/interventions in the early post-operative period. Additionally, this is also the first study to examine extent of surgery as a co-factor in post-operative airway issues. Overall, the majority of patients undergoing supraglottoplasty (83.9%) did not require ICU-level airway intervention. This finding is consistent with previous reports, and also supports those recommending ‘step-down unit’ observation for these patients [7,9]. The results herein suggest that use of the CO2 laser for supraglottoplasty is associated with an increased risk prolonged ICU-stay (OR 3.42, 95% CI 1.39, 8.40), as well as airway interventions (NIPPV, administration of racemic epinephrine, and endotracheal intubation). CO2 laser, particularly with a non-pulsed laser-beam, has been found to cause thermal injury to the surrounding tissue [10,11]. The resulting tissue damage and edema can theoretically result in a higher incidence of airway events post-operatively. Additionally, set-up and positioning of the CO2 laser may increase operative time and time under laryngeal suspension, potentially increasing the amount of postoperative edema. In previous literature, the series reporting a large proportion of CO2 laser supraglottoplasties appeared to have a higher incidence of airway events (63% and 28.5%) [6,8], in comparison to those of predominantly cold-steel cases (4.5% and 11.2%) [5,7]. This observation, while not a direct comparison, also appears to support the hypothesis. Thirdly, the extent of surgery may also play a role by increasing the operative time as well as the collateral tissue damage, though this has not previously been studied. Upon superficial examination of event rates, the extent of surgery did appear to influence the early post-operative outcomes, with 22% (11/50) patients undergoing resection of arytenoid mucosa ± division of AE folds required prolonged ICU-stay, compared to 13% (14/105) of patients who underwent division of AE folds alone. However, the regression model did not identify a statistically higher risk of prolonged ICU stay in the patients who underwent more extensive surgery (OR1.82, 95%CI: 0.77, 4.40; p = 0.17). Furthermore, when comparing only the patients who underwent division of AE folds, the CO2 laser appeared to result in a higher risk of prolonged ICU-stay than cold-steel (66% - 4/6 vs. 10.1% - 10/99, respectively, p = 0.003). When comparing patients who underwent more extensive supraglottoplasty, no statistical difference was found (CO2: 10/43–23.3% vs. cold-steel: 1/ 7–14.3%, p = 0.99) (Table 4). The operative duration also corroborates the notion that extent of surgery did not increase the risk of prolonged ICU stay. One would expect that more extensive surgery would increase the operative time. But, the operative time of patients who required prolonged ICU-stay (69.2 [SD 48.0] minutes) was not significantly longer than those not requiring prolonged ICU-stay (55.6 [SD 45.4] minutes), thus also suggesting that extent of surgery did not play a major role. The analysis of surgical extent was somewhat limited, as the event rate was low overall and the majority of cold-steel cases consisted of less extensive surgery, while the majority of CO2 laser cases were more extensive. This remains one of the limitations of this study, though it highlights for the first time in the literature the importance of recognizing that not all supraglottoplasties are equivalent. The largest series published to-date on this subject identified several risk factors for prolonged ICU-stay – non-white race, duration of
Table 2 Operative details. Surgery Type Total Division of aryepiglottic folds alone Resection of arytenoid mucosa alone Combined division + resection
Total
CO2 laser
Cold-steel
155 105 (67.7%) 15 (9.6%) 35 (22.6%)
49 6 (12.2%) 12 (24.5%) 31 (63.3%)
106 99 (93.4%) 3 (2.8%) 4 (3.8%)
The extent of surgery differed by CO2 laser vs. cold-steel (p < 0.001 based on the Chi-square test).
(10.3%) required NIPPV, and 12 (7.7%) nebulized racemic epinephrine. The CO2 laser group had a significantly higher proportion of patients requiring prolonged ICU-stay in comparison to the cold-steel group (28.6% versus 10.4%, OR 3.42, 95% CI 1.39,8.40). The CO2 laser group were more likely to require intubation (10.2% versus 1.9%), NIPPV (20.4% versus 5.7%), and racemic epinephrine (16.3% versus 3.8%) compared to the cold-steel group (Table 3). The median age did not differ between the CO2 laser group and the cold-steel group (8.5 months [IQR: 3.7–20.4] vs. 7.1 months [IQR: 2.7–26.7]; p = 0.41). The mean length of stay was higher in the CO2 laser group (3.3 [SD 5.7]; median 2 days) than the cold-steel group (2.6 [SD 7.0]; median 1 day; p < 0.01). The mean (SD) operative time was 76.8 (36.0) minutes in the CO2 laser group, versus 46.1 (36.1) minutes in the cold-steel group (p < 0.001). The mean operative time in patients who required prolonged ICU-stay was 69.2 (48.0) minutes, compared to 55.6 (45.4) minutes in patients who did not have the outcome of interest (p = 0.15). Regarding extent of surgery, 105 patients underwent division of AE folds alone, and in this group, 10.1% (14/105) required prolonged ICUstay. Fifty patients underwent resection of arytenoid mucosa with or without division of AE folds, and in this group 22% (11/50) required prolonged ICU-stay (Table 4). The extend of surgery was not associated with a prolonged ICU-stay (OR 1.82; 95% CI 0.77, 4.40; p = 0.13). In the multivariable regression model, CO2 laser supraglottoplasty (adjusted OR 3.42; 95% CI 1.39, 8.40) and history of a neurological disorder (adjusted OR 3.30; 95% CI 1.18, 9.28) were significant risk factors for requiring prolonged ICU-stay (Table 5). Other factors such age, duration of surgery, and severe respiratory distress were not associated with a prolonged ICU-stay. 4. Discussion 4.1. Key results and interpretation The degree of post-operative monitoring following supraglottoplasty continues to be variable, both among different institutions, as well as within institutions [2]. Due to the risk of airway edema and obstruction, patients were traditionally admitted to the ICU. Indeed, the earlier reports of post-operative outcomes of these patients found that 63% (33/52) of patients required nonsurgical airway support and 15% (8/52) required revision surgery [6]. More recent series have reported significantly lower incidences of airway interventions, ranging from 4.5% to 28.5% [5,7–9]. Only two previous studies have assessed the effect surgical instrument on early post-operative outcomes and neither identified a difference in rate of complications, including planned/ Table 3 Perioperative outcomes by instrument technique.
Prolonged ICU Intubated NIPPV Racemic epinephrine
CO2 laser (n = 49)
Cold-steel (n = 106)
OR (95% CI)
p-value
14 (28.6%) 5 (10.2%) 10 (20.4%) 8 (16.3%)
11 (10.4%) 2 (1.9%) 6 (5.7%) 4 (3.8%)
3.46 5.91 4.27 4.98
0.006 0.03 0.005 0.02
ICU – intensive care unit, NIPPV – non-invasive positive pressure ventilation, OR – odds ratio, CI – confidence interval. 3
(1.43, (1.10, (1.45, (1.42,
8.33) 31.62) 12.55) 17.43)
International Journal of Pediatric Otorhinolaryngology 130 (2020) 109843
J.C. Yeung, et al.
Table 4 Perioperative outcomes by extent of surgery.
Division of aryepiglottic folds alone Arytenoid mucosa resection with or without Division of aryepiglotti folds Total
CO2 laser prolonged ICU/total cases (%)
Cold-steel prolonged ICU/total cases (%)
p-value
4/6 (66.7%) 10/43 (23.3%) 14/49 (28.6%)
10/99 (10.1%) 1/7 (14.3%) 11/105 (10.4%)
0.003 0.99 0.006
ICU – intensive care unit. Table 5 Factors associated with prolonged ICU-stay.
Laser procedure Resection of arytenoid mucosa Duration of surgery > 30 min Age < 6 months Race (White vs. non-White) Comorbidities Neurological Syndrome Pulmonary Cardiac Severe respiratory distress
Unadjusted OR (95% CI)
p-value
Adjusted OR (95% CI)
p-value
3.46 (1.43, 8.33) 1.82 (0.77, 4.40) 1.68 (0.63, 4.50) 1.63 (0.69, 3.86) 1.32 (0.54, 3.22)
0.006 0.17 0.30 0.27 0.54
3.42 (1.39, 8.40) –
0.01
3.35 (1.25, 9.02) 2.25 (0.72, 7.00) 1.17 (0.24, 5.77) 0.45 (0.06, 3.66) 2.08 (0.87, 4.95)
0.02 0.16 0.84 0.46 0.10
3.30 (1.18, 9.23) – – – –
– – 0.02
analysis was only performed in patients undergoing division of AE folds and/or resection of arytenoid mucosa, and excluded patients undergoing surgery of the epiglottis. The current study was the first to systematically investigate the surgical instrument as well as the extent of surgery in post-operative supraglottoplasty outcomes. In doing so, it observed an association between patients undergoing CO2 laser supraglottoplasty and prolonged ICU-stay as well as ICU-level airway interventions, when compared to those undergoing cold-steel supraglottoplasty. While this should not be misconstrued as a causal relationship, this association remains plausible and undoubtedly warrants further study. Most notably, the extent of surgery may play a role, and the above results emphasize the critical importance of consistently detailing surgical extent when reporting outcomes of supraglottoplasty in future. Further research is required to determine the role of surgical extent and specific laser characteristics, such as pulse mode, on early post-operative outcomes of patients undergoing supraglottoplasty.
surgery greater than 30 min, use of the microscope, and pre-operative oxygen requirement [7]. When risk factors were examined in the current study, only the presence of comorbid neurologic condition was found to increase the risk of prolonged ICU-stay. Duration of surgery > 30 min, non-white race, and younger age did not increase the risk of prolonged ICU-stay (Table 5). Despite this finding, patients with neurologic condition appear to perform favourably in the long-term in comparison to other syndromic/complex patients [12]. Interestingly, Albergotti et al. did not identify use of the laser as a risk factor, though this instrument was used in only 3.4% (7/206) their cases [7]. 4.2. Limitations The primary limitation of this study was the low incidence of prolonged ICU-stay and airway events/interventions, thereby limiting the power to detect multiple risk factors for prolonged ICU-stay. This may explain differences observed in the current data compared to prior studies [7]. Moreover, pertaining extent of surgery, CO2 laser was used frequently to perform resection of the arytenoid mucosa, whereas coldsteel instruments were frequently used for division of AE folds. This may have limited the ability to isolate the true contributing factor. Nonetheless, the regression model did not identify surgical extent or duration as contributing factors. Second, due to variations in charting methodology, it was difficult to systematically report the amount of post-operative oxygen administration and consequently, this was not included as a secondary outcome. Third, the pulse mode of the CO2 laser was not indicated in the operative notes and consequently not reported in this study. The aggressiveness of laser use may also influence the degree of post-operative edema and this factor could not be assessed with the available data.
Financial disclosure None. Declaration of competing interest None. References [1] G.T. Richter, D.M. Thompson, The surgical management of laryngomalacia, Otolaryngol. Clin. N. Am. 41 (2008), https://doi.org/10.1016/j.otc.2008.04.011 837–64– vii. [2] V.H. Ramprasad, M.A. Ryan, A.E. Farjat, R.J. Eapen, E.M. Raynor, Practice patterns in supraglottoplasty and perioperative care, Int. J. Pediatr. Otorhinolaryngol. 86 (2016) 118–123, https://doi.org/10.1016/j.ijporl.2016.04.039. [3] C.M. Douglas, A. Shafi, G. Higgins, K. Blackmore, D.M. Wynne, H. Kubba, et al., Risk factors for failure of supraglottoplasty, Int. J. Pediatr. Otorhinolaryngol. 78 (2014) 1485–1488, https://doi.org/10.1016/j.ijporl.2014.06.014. [4] K.E. Day, C.M. Discolo, J.D. Meier, B.J. Wolf, L.A. Halstead, D.R. White, Risk factors for supraglottoplasty failure, Otolaryngol. Head Neck Surg.: Off. J. Am. Acad. Otolaryngol. Head Neck Surg. 146 (2012) 298–301, https://doi.org/10.1177/ 0194599811425652. [5] M.T. Fordham, S.M. Potter, D.R. White, Postoperative management following supraglottoplasty for severe laryngomalacia, The Laryngoscope 123 (2013) 3206–3210, https://doi.org/10.1002/lary.24108. [6] J.W. Schroeder, N.D. Bhandarkar, L.D. Holinger, Synchronous airway lesions and
4.3. Generalisability The baseline characteristics of the patient population is expected, given the tertiary/quaternary referral pattern of Boston Children's Hospital. The proportion of complex children is slightly higher than previous studies investigating post-operative supraglottoplasty outcomes; though, the overall rate of prolonged ICU-stay was within the range of reported incidences [3,5–9]. The current study did not include patients who required pre-operative ICU stay, patients undergoing concomitant airway surgery, or revision cases. Finally, comparative 4
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Otorhinolaryngol. 116 (2019) 181–185, https://doi.org/10.1016/j.ijporl.2018.11. 003. [10] A. Böttcher, S. Kucher, R. Knecht, N. Jowett, P. Krötz, R. Reimer, et al., Reduction of thermocoagulative injury via use of a picosecond infrared laser (PIRL) in laryngeal tissues, Eur. Arch. Oto-Rhino-Laryngol. 272 (2015) 941–948, https://doi.org/10. 1007/s00405-015-3501-4. [11] C.G. Garrett, L. Reinisch, New-generation pulsed carbon dioxide laser: comparative effects on vocal fold wound healing, Ann. Otol. Rhinol. Laryngol. 111 (2002) 471–476, https://doi.org/10.1177/000348940211100601. [12] V.S.P.B. Durvasula, B.R. Lawson, C.M. Bower, G.T. Richter, Supraglottoplasty in premature infants with laryngomalacia, Otolaryngol. Head Neck Surg. 150 (2014) 292–299, https://doi.org/10.1177/0194599813514370.
outcomes in infants with severe laryngomalacia requiring supraglottoplasty, Arch. Otolaryngol. Head Neck Surg. 135 (2009) 647–651, https://doi.org/10.1001/ archoto.2009.73. [7] W.G. Albergotti, J.J. Sturm, A.S. Stapleton, J.P. Simons, D.K. Mehta, D.H. Chi, Predictors of intensive care unit stay after pediatric supraglottoplasty, JAMA Otolaryngol. Head Neck Surg. 141 (2015) 704–709, https://doi.org/10.1001/ jamaoto.2015.1033. [8] S. Chan, G. Siou, A. Welch, S. Powell, Predictors for routine admission to paediatric intensive care for post-supraglottoplasty laryngomalacia patients, J. Laryngol. Otol. 131 (2017) 640–644, https://doi.org/10.1017/S0022215117001074. [9] D.W. Chen, Y.-C.C. Liu, Routine admission to step-down unit as an alternative to intensive care unit after pediatric supraglottoplasty, Int. J. Pediatr.
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International Journal of Pediatric Otorhinolaryngology journal homepage: www.elsevier.com/locate/ijporl
Carbon dioxide laser versus cold-steel supraglottoplasty: A comparison of post-operative outcomes
T
Jeffrey C. Yeunga,b,∗, Syed O. Alib, Mallory G. McKeonb, Samantha Grenierb, Kosuke Kawaib, Reza Rahbarb,c, Karen F. Wattersb,c Department of Otolaryngology – Head & Neck Surgery, McGill University, Canada Department of Otolaryngology and Communication Enhancement, Boston Children's Hospital, USA c Department of Otology and Laryngology, Harvard Medical School, USA a
b
A R T I C LE I N FO
A B S T R A C T
Keywords: Supraglottoplasty Pediatric CO2 laser Post-operative outcomes
Objective: Supraglottoplasty is the mainstay of surgical treatment for laryngomalacia, and is commonly performed via two methods: cold steel or carbon dioxide (CO2) laser. The degree of post-operative monitoring following supraglottoplasty varies, both within and between institutions. The aim of this study was to compare the post-operative monitoring and interventions required by patients undergoing cold-steel versus CO2 laser supraglottoplasty. Design: Retrospective cohort of pediatric patients (age < 18 years) undergoing supraglottoplasty at a tertiary care pediatric hospital. The primary exposure was the surgical instrument(s) used during supraglottoplasty. The primary outcome was prolonged intensive care unit (ICU)-stay (defined as > 24 h). Results: 155 cases were eligible for inclusion. Fifty-eight (37.4%) patients had a comorbid condition. Common indications for surgery included feeding difficulty (56.1%), severe respiratory distress (33.5%), and obstructive sleep apnea (25.2%). CO2 laser was employed in 49 cases and cold-steel in 106 cases. Prolonged ICU-stay (> 24 h) was observed in 14 CO2 laser cases (28.6%) and 11 cold-steel cases (10.4%) (adjusted OR 3.42; 95% CI 1.43, 8.33). CO2 laser cases were more likely to require post-operative intubation, non-invasive positive pressure ventilation, and nebulized racemic epinephrine. Concomitant neurological condition was associated with an increased risk of prolonged ICU-stay, while extent of surgery and age were not. Conclusions: CO2 laser supraglottoplasty is associated with an increased risk of prolonged ICU-stay and need for ICU-level airway intervention, compared to the cold-steel technique. While this association should not be misconstrued as a causal relationship, the current study demonstrates that specific surgical factors may influence the patient monitoring requirements following supraglottoplasty, particularly the choice of instrument and the extent of surgery.
1. Introduction Laryngomalacia is the most common cause of infant stridor, and a common reason for Otolaryngology referral. While the majority will resolve spontaneously, up to 20% of patients with laryngomalacia require surgical management [1]. The mainstay of surgical therapy is supraglottoplasty, a term that encompasses the removal of excess/redundant arytenoid mucosa, division of the aryepiglottic (AE) folds, epiglottopexy or a combination of these. Supraglottoplasty may be performed using several instruments, most commonly with cold-steel dissection or carbon dioxide (CO2) laser [2]. Both surgical instruments produce equivalent post-operative outcomes in the long-term [3,4]. The
∗
decision on the extent of surgery is generally made at the discretion of the surgeon and is based on clinical endoscopic examination as well as the operative examination. The post-operative monitoring for patients varies both within and between institutions. Traditionally for airway surgery, routine postoperative monitoring in an intensive-care unit (ICU) has been standard of practice, and over half of otolaryngologists surveyed (53%) through the Society for Ear Nose and Throat Advances in Children adhere to this practice [2]. However, the percentage of patients needing ICU-level intervention following supraglottoplasty (i.e. intubation, non-invasive positive pressure ventilation [NIPPV], high-flow oxygen) has reported to be as low as 5% and as high as 63% [5–9]. Recent reports have
Corresponding author. Department of Otolaryngology – Head & Neck Surgery, McGill University Health Center, Montreal, Canada. E-mail address: jeff[email protected] (J.C. Yeung).
https://doi.org/10.1016/j.ijporl.2019.109843 Received 28 August 2019; Received in revised form 17 December 2019; Accepted 17 December 2019 Available online 24 December 2019 0165-5876/ © 2019 Published by Elsevier B.V.
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advocated for close peri-operative monitoring outside of the ICU for several hours to better allocate ICU resources [7,9]. Determining which patients require ICU-level airway intervention post-operatively, as well as factors influencing this decision, are essential in providing safe and efficient care to this patient population. The aim of this study was to determine whether use of the CO2 laser affects the early post-operative outcomes in patients undergoing supraglottoplasty.
Table 1 Patient characteristics.
Primary supraglottoplasty Male History of prematurity Patients with at least one comorbidity Cardiac Neurological Pulmonary Transplant/immunological Syndromic Other Presenting Symptoms Stridor Reflux Cyanosis Apnea Failure to thrive Indication for Surgery Failure to thrive Obstructive sleep apnea Severe respiratory distress Feeding difficulty Other
2. Methods A retrospective cohort study was performed following institutional research ethics approval. The study took place in a tertiary care pediatric hospital setting and studied patients with laryngomalacia undergoing supraglottoplasty between January 2009 and December 2016. This cohort represented surgeries performed by all attending physicians employed during the study period and the choice of instrument was based on individual surgeon-preference. Patients diagnosed with laryngomalacia during the study period were identified using International Statistical Classification of Diseases and Related Health Problems Codes (ICD-10 Q31.5 and/or ICD-9-CM 748.3). These were cross-referenced with patients who underwent supraglottoplasty using Current Procedural Terminology Codes (31599, 31541, and 31588). Patient characteristics obtained from the medical record included demographic information, presenting symptoms, comorbid conditions, indication(s) for surgery, physical findings, pertinent diagnostic tests, surgery date, operative records, anesthetic records and results of investigative testing. All patients (age < 18) undergoing supraglottoplasty were eligible for inclusion. Exclusion criteria consisted of patients undergoing concomitant airway surgery, revision surgery, and those who required ICU-stay pre-operatively. All data was entered into a REDCap Database (Vanderbilt University, Nashville TN). The primary exposure of interest was the surgical instrument used for supraglottoplasty. Patients were assigned to the cold-steel group if their entire surgery was performed using only cold-steel microlaryngeal instruments. Patients were assigned to the CO2 laser group if any portion of the supraglottoplasty was performed using CO2 laser. Operative records were reviewed to determine the extent of supraglottoplasty (division of AE folds, resection of arytenoid mucosa, epiglottopexy or combination) as well as the instrument(s) utilized (cold-steel, CO2 laser, powered instrument or combination). The primary outcome of interest was prolonged ICU-stay, as defined as > 24 h. Secondary outcomes of interest were ICU-level airway interventions, including use of nebulized racemic epinephrine positivepressure ventilation, NIPPV, and endotracheal intubation. Risk adjustment was carried out for young patients (age < 6 months), history of prematurity, history of comorbid condition, duration of surgery, and extent of surgery (division of AE folds, arytenoid mucosa resection, or both). To compare the characteristics of patients who underwent cold-steel vs. CO2 laser supraglottoplasty, we used Chi-square or Fisher's exact test for categorical variables and Wilcoxon rank sum test for continuous variables. A logistic regression model was used to examine risk factors associated with a prolonged ICU-stay. Odds ratio (OR) and 95% confidence interval (CI) were estimated. Any potential risk factors with p < 0.20 in univariate analyses were considered as candidates for the multivariable analyses. The final multivariable regression model was built using backward selection procedure with p < 0.05 as the retention criteria. Statistical analyses were conducted using SAS version 9.4 (SAS Institute, Cary, NC).
Total
CO2 laser
Cold-steel
155 96 (61.9%) 25 (16.1%) 58 (37.4%) 12 (7.7%) 24 (15.5%) 11 (7.1%) 1 (0.7%) 18 (11.6%) 19 (12.3%)
49 29 (59.2%) 8 (16.3%) 21 (42.9%) 7 (14.3%) 9 (18.4%) 5 (10.2%) 0 (0%) 6 (12.2%) 9 (18.4%)
106 67 (63.2%) 17 (16.0%) 37 (34.9%) 5 (4.7%) 15 (14.2%) 6 (5.7%) 1 (0.9%) 12 (11.3%) 10 (9.4%)
134 (86.5%) 56 (36.1%) 7 (4.5%) 40 (25.8%) 18 (11.6%)
39 (79.6%) 17 (34.7%) 2 (4.0%) 18 (36.7%) 5 (10.2%)
95 (89.6%) 39 (36.8%) 5 (4.7%) 22 (20.8%) 13 (12.3%)
23 39 52 87 31
9 (18.4%) 17 (34.7%) 19 (38.8%) 24 (49.0%) 13 (26.5%)
14 22 33 63 18
(14.8%) (25.2%) (33.5%) (56.1%) (20.0%)
(13.2%) (20.8%) (31.1%) (59.4%) (17.0%)
supraglottoplasty during the study period. Forty-five were excluded: 2 due to incomplete medical records, 8 due to concomitant airway surgery, 33 due to pre-operative ICU-stay, and 2 patients were undergoing revision surgery. Further, 3 epiglottopexy patients were excluded. 155 eligible patients were included in the study. 3.2. Descriptive data Of 155 supraglottoplasties performed, 96 (61.9%) were male (Table 1). The median age at the time of surgery was 8 months (interquartile range [IQR] 3–22 months). Twenty-five (16.1%) patients had a history of prematurity (born at less than 37 weeks gestational age). The median gestational age of premature patients was 33 weeks (IQR 30–35 weeks). The most common presenting symptoms were stridor (86.5%), reflux (36.1%), apneic events (25.8%), and failure to thrive (11.6%). Fifty-eight (37.4%) patients had a comorbid condition, namely cardiac (7.7%), neurologic (15.5%), pulmonary (7.1%), and syndromes (11.6%). The most common indications for supraglottoplasty were feeding difficulty (56.1%), severe respiratory events (33.5%), and obstructive sleep apnea (25.2%). All patients undergoing surgery were given a single dose of preoperative corticosteroids (intravenous dexamethasone 0.5 mg/kg). All supraglottoplasties were immediately preceded by direct laryngoscopy and bronchoscopy. The most common secondary airway lesions identified were laryngeal cleft (16), tracheomalacia (6), subglottic stenosis (4), and vocal cord paralysis (1). Sixteen patients had other findings on bronchoscopy not classified as above, specifically 1) narrowing that was not classified as stenosis; 2) submucosal mass, 3) blunted carina, 4) edematous distal trachea, and/ or 5) deep interarytenoid groove. Of 155 supraglottoplasties performed, 106 (67.1%) of the supraglottoplasties were performed with cold-steel technique and 49 (31.0%) with the CO2 laser. One hundred five (67.7%) patients underwent division of the AE folds alone, 15 (9.6%) underwent resection of the arytenoid mucosa alone, and 35 (22.6%) underwent a combination of both. The mean (SD) operative time was 55.8 (38.7) minutes. The extent of surgery is summarized in Table 2.
3. Results 3.3. Outcome Data 3.1. Participants Overall, 25 of 155 (16.1%) of patients required prolonged ICU-stay post-operatively. Of these patients, 7 (4.5%) required intubation, 16
203 patients were identified with laryngomalacia undergoing 2
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unplanned ICU admission [3,7]. The current study was designed to determine if use of the CO2 laser during supraglottoplasty was associated with higher incidence of airway events/interventions in the early post-operative period. Additionally, this is also the first study to examine extent of surgery as a co-factor in post-operative airway issues. Overall, the majority of patients undergoing supraglottoplasty (83.9%) did not require ICU-level airway intervention. This finding is consistent with previous reports, and also supports those recommending ‘step-down unit’ observation for these patients [7,9]. The results herein suggest that use of the CO2 laser for supraglottoplasty is associated with an increased risk prolonged ICU-stay (OR 3.42, 95% CI 1.39, 8.40), as well as airway interventions (NIPPV, administration of racemic epinephrine, and endotracheal intubation). CO2 laser, particularly with a non-pulsed laser-beam, has been found to cause thermal injury to the surrounding tissue [10,11]. The resulting tissue damage and edema can theoretically result in a higher incidence of airway events post-operatively. Additionally, set-up and positioning of the CO2 laser may increase operative time and time under laryngeal suspension, potentially increasing the amount of postoperative edema. In previous literature, the series reporting a large proportion of CO2 laser supraglottoplasties appeared to have a higher incidence of airway events (63% and 28.5%) [6,8], in comparison to those of predominantly cold-steel cases (4.5% and 11.2%) [5,7]. This observation, while not a direct comparison, also appears to support the hypothesis. Thirdly, the extent of surgery may also play a role by increasing the operative time as well as the collateral tissue damage, though this has not previously been studied. Upon superficial examination of event rates, the extent of surgery did appear to influence the early post-operative outcomes, with 22% (11/50) patients undergoing resection of arytenoid mucosa ± division of AE folds required prolonged ICU-stay, compared to 13% (14/105) of patients who underwent division of AE folds alone. However, the regression model did not identify a statistically higher risk of prolonged ICU stay in the patients who underwent more extensive surgery (OR1.82, 95%CI: 0.77, 4.40; p = 0.17). Furthermore, when comparing only the patients who underwent division of AE folds, the CO2 laser appeared to result in a higher risk of prolonged ICU-stay than cold-steel (66% - 4/6 vs. 10.1% - 10/99, respectively, p = 0.003). When comparing patients who underwent more extensive supraglottoplasty, no statistical difference was found (CO2: 10/43–23.3% vs. cold-steel: 1/ 7–14.3%, p = 0.99) (Table 4). The operative duration also corroborates the notion that extent of surgery did not increase the risk of prolonged ICU stay. One would expect that more extensive surgery would increase the operative time. But, the operative time of patients who required prolonged ICU-stay (69.2 [SD 48.0] minutes) was not significantly longer than those not requiring prolonged ICU-stay (55.6 [SD 45.4] minutes), thus also suggesting that extent of surgery did not play a major role. The analysis of surgical extent was somewhat limited, as the event rate was low overall and the majority of cold-steel cases consisted of less extensive surgery, while the majority of CO2 laser cases were more extensive. This remains one of the limitations of this study, though it highlights for the first time in the literature the importance of recognizing that not all supraglottoplasties are equivalent. The largest series published to-date on this subject identified several risk factors for prolonged ICU-stay – non-white race, duration of
Table 2 Operative details. Surgery Type Total Division of aryepiglottic folds alone Resection of arytenoid mucosa alone Combined division + resection
Total
CO2 laser
Cold-steel
155 105 (67.7%) 15 (9.6%) 35 (22.6%)
49 6 (12.2%) 12 (24.5%) 31 (63.3%)
106 99 (93.4%) 3 (2.8%) 4 (3.8%)
The extent of surgery differed by CO2 laser vs. cold-steel (p < 0.001 based on the Chi-square test).
(10.3%) required NIPPV, and 12 (7.7%) nebulized racemic epinephrine. The CO2 laser group had a significantly higher proportion of patients requiring prolonged ICU-stay in comparison to the cold-steel group (28.6% versus 10.4%, OR 3.42, 95% CI 1.39,8.40). The CO2 laser group were more likely to require intubation (10.2% versus 1.9%), NIPPV (20.4% versus 5.7%), and racemic epinephrine (16.3% versus 3.8%) compared to the cold-steel group (Table 3). The median age did not differ between the CO2 laser group and the cold-steel group (8.5 months [IQR: 3.7–20.4] vs. 7.1 months [IQR: 2.7–26.7]; p = 0.41). The mean length of stay was higher in the CO2 laser group (3.3 [SD 5.7]; median 2 days) than the cold-steel group (2.6 [SD 7.0]; median 1 day; p < 0.01). The mean (SD) operative time was 76.8 (36.0) minutes in the CO2 laser group, versus 46.1 (36.1) minutes in the cold-steel group (p < 0.001). The mean operative time in patients who required prolonged ICU-stay was 69.2 (48.0) minutes, compared to 55.6 (45.4) minutes in patients who did not have the outcome of interest (p = 0.15). Regarding extent of surgery, 105 patients underwent division of AE folds alone, and in this group, 10.1% (14/105) required prolonged ICUstay. Fifty patients underwent resection of arytenoid mucosa with or without division of AE folds, and in this group 22% (11/50) required prolonged ICU-stay (Table 4). The extend of surgery was not associated with a prolonged ICU-stay (OR 1.82; 95% CI 0.77, 4.40; p = 0.13). In the multivariable regression model, CO2 laser supraglottoplasty (adjusted OR 3.42; 95% CI 1.39, 8.40) and history of a neurological disorder (adjusted OR 3.30; 95% CI 1.18, 9.28) were significant risk factors for requiring prolonged ICU-stay (Table 5). Other factors such age, duration of surgery, and severe respiratory distress were not associated with a prolonged ICU-stay. 4. Discussion 4.1. Key results and interpretation The degree of post-operative monitoring following supraglottoplasty continues to be variable, both among different institutions, as well as within institutions [2]. Due to the risk of airway edema and obstruction, patients were traditionally admitted to the ICU. Indeed, the earlier reports of post-operative outcomes of these patients found that 63% (33/52) of patients required nonsurgical airway support and 15% (8/52) required revision surgery [6]. More recent series have reported significantly lower incidences of airway interventions, ranging from 4.5% to 28.5% [5,7–9]. Only two previous studies have assessed the effect surgical instrument on early post-operative outcomes and neither identified a difference in rate of complications, including planned/ Table 3 Perioperative outcomes by instrument technique.
Prolonged ICU Intubated NIPPV Racemic epinephrine
CO2 laser (n = 49)
Cold-steel (n = 106)
OR (95% CI)
p-value
14 (28.6%) 5 (10.2%) 10 (20.4%) 8 (16.3%)
11 (10.4%) 2 (1.9%) 6 (5.7%) 4 (3.8%)
3.46 5.91 4.27 4.98
0.006 0.03 0.005 0.02
ICU – intensive care unit, NIPPV – non-invasive positive pressure ventilation, OR – odds ratio, CI – confidence interval. 3
(1.43, (1.10, (1.45, (1.42,
8.33) 31.62) 12.55) 17.43)
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Table 4 Perioperative outcomes by extent of surgery.
Division of aryepiglottic folds alone Arytenoid mucosa resection with or without Division of aryepiglotti folds Total
CO2 laser prolonged ICU/total cases (%)
Cold-steel prolonged ICU/total cases (%)
p-value
4/6 (66.7%) 10/43 (23.3%) 14/49 (28.6%)
10/99 (10.1%) 1/7 (14.3%) 11/105 (10.4%)
0.003 0.99 0.006
ICU – intensive care unit. Table 5 Factors associated with prolonged ICU-stay.
Laser procedure Resection of arytenoid mucosa Duration of surgery > 30 min Age < 6 months Race (White vs. non-White) Comorbidities Neurological Syndrome Pulmonary Cardiac Severe respiratory distress
Unadjusted OR (95% CI)
p-value
Adjusted OR (95% CI)
p-value
3.46 (1.43, 8.33) 1.82 (0.77, 4.40) 1.68 (0.63, 4.50) 1.63 (0.69, 3.86) 1.32 (0.54, 3.22)
0.006 0.17 0.30 0.27 0.54
3.42 (1.39, 8.40) –
0.01
3.35 (1.25, 9.02) 2.25 (0.72, 7.00) 1.17 (0.24, 5.77) 0.45 (0.06, 3.66) 2.08 (0.87, 4.95)
0.02 0.16 0.84 0.46 0.10
3.30 (1.18, 9.23) – – – –
– – 0.02
analysis was only performed in patients undergoing division of AE folds and/or resection of arytenoid mucosa, and excluded patients undergoing surgery of the epiglottis. The current study was the first to systematically investigate the surgical instrument as well as the extent of surgery in post-operative supraglottoplasty outcomes. In doing so, it observed an association between patients undergoing CO2 laser supraglottoplasty and prolonged ICU-stay as well as ICU-level airway interventions, when compared to those undergoing cold-steel supraglottoplasty. While this should not be misconstrued as a causal relationship, this association remains plausible and undoubtedly warrants further study. Most notably, the extent of surgery may play a role, and the above results emphasize the critical importance of consistently detailing surgical extent when reporting outcomes of supraglottoplasty in future. Further research is required to determine the role of surgical extent and specific laser characteristics, such as pulse mode, on early post-operative outcomes of patients undergoing supraglottoplasty.
surgery greater than 30 min, use of the microscope, and pre-operative oxygen requirement [7]. When risk factors were examined in the current study, only the presence of comorbid neurologic condition was found to increase the risk of prolonged ICU-stay. Duration of surgery > 30 min, non-white race, and younger age did not increase the risk of prolonged ICU-stay (Table 5). Despite this finding, patients with neurologic condition appear to perform favourably in the long-term in comparison to other syndromic/complex patients [12]. Interestingly, Albergotti et al. did not identify use of the laser as a risk factor, though this instrument was used in only 3.4% (7/206) their cases [7]. 4.2. Limitations The primary limitation of this study was the low incidence of prolonged ICU-stay and airway events/interventions, thereby limiting the power to detect multiple risk factors for prolonged ICU-stay. This may explain differences observed in the current data compared to prior studies [7]. Moreover, pertaining extent of surgery, CO2 laser was used frequently to perform resection of the arytenoid mucosa, whereas coldsteel instruments were frequently used for division of AE folds. This may have limited the ability to isolate the true contributing factor. Nonetheless, the regression model did not identify surgical extent or duration as contributing factors. Second, due to variations in charting methodology, it was difficult to systematically report the amount of post-operative oxygen administration and consequently, this was not included as a secondary outcome. Third, the pulse mode of the CO2 laser was not indicated in the operative notes and consequently not reported in this study. The aggressiveness of laser use may also influence the degree of post-operative edema and this factor could not be assessed with the available data.
Financial disclosure None. Declaration of competing interest None. References [1] G.T. Richter, D.M. Thompson, The surgical management of laryngomalacia, Otolaryngol. Clin. N. Am. 41 (2008), https://doi.org/10.1016/j.otc.2008.04.011 837–64– vii. [2] V.H. Ramprasad, M.A. Ryan, A.E. Farjat, R.J. Eapen, E.M. Raynor, Practice patterns in supraglottoplasty and perioperative care, Int. J. Pediatr. Otorhinolaryngol. 86 (2016) 118–123, https://doi.org/10.1016/j.ijporl.2016.04.039. [3] C.M. Douglas, A. Shafi, G. Higgins, K. Blackmore, D.M. Wynne, H. Kubba, et al., Risk factors for failure of supraglottoplasty, Int. J. Pediatr. Otorhinolaryngol. 78 (2014) 1485–1488, https://doi.org/10.1016/j.ijporl.2014.06.014. [4] K.E. Day, C.M. Discolo, J.D. Meier, B.J. Wolf, L.A. Halstead, D.R. White, Risk factors for supraglottoplasty failure, Otolaryngol. Head Neck Surg.: Off. J. Am. Acad. Otolaryngol. Head Neck Surg. 146 (2012) 298–301, https://doi.org/10.1177/ 0194599811425652. [5] M.T. Fordham, S.M. Potter, D.R. White, Postoperative management following supraglottoplasty for severe laryngomalacia, The Laryngoscope 123 (2013) 3206–3210, https://doi.org/10.1002/lary.24108. [6] J.W. Schroeder, N.D. Bhandarkar, L.D. Holinger, Synchronous airway lesions and
4.3. Generalisability The baseline characteristics of the patient population is expected, given the tertiary/quaternary referral pattern of Boston Children's Hospital. The proportion of complex children is slightly higher than previous studies investigating post-operative supraglottoplasty outcomes; though, the overall rate of prolonged ICU-stay was within the range of reported incidences [3,5–9]. The current study did not include patients who required pre-operative ICU stay, patients undergoing concomitant airway surgery, or revision cases. Finally, comparative 4
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Otorhinolaryngol. 116 (2019) 181–185, https://doi.org/10.1016/j.ijporl.2018.11. 003. [10] A. Böttcher, S. Kucher, R. Knecht, N. Jowett, P. Krötz, R. Reimer, et al., Reduction of thermocoagulative injury via use of a picosecond infrared laser (PIRL) in laryngeal tissues, Eur. Arch. Oto-Rhino-Laryngol. 272 (2015) 941–948, https://doi.org/10. 1007/s00405-015-3501-4. [11] C.G. Garrett, L. Reinisch, New-generation pulsed carbon dioxide laser: comparative effects on vocal fold wound healing, Ann. Otol. Rhinol. Laryngol. 111 (2002) 471–476, https://doi.org/10.1177/000348940211100601. [12] V.S.P.B. Durvasula, B.R. Lawson, C.M. Bower, G.T. Richter, Supraglottoplasty in premature infants with laryngomalacia, Otolaryngol. Head Neck Surg. 150 (2014) 292–299, https://doi.org/10.1177/0194599813514370.
outcomes in infants with severe laryngomalacia requiring supraglottoplasty, Arch. Otolaryngol. Head Neck Surg. 135 (2009) 647–651, https://doi.org/10.1001/ archoto.2009.73. [7] W.G. Albergotti, J.J. Sturm, A.S. Stapleton, J.P. Simons, D.K. Mehta, D.H. Chi, Predictors of intensive care unit stay after pediatric supraglottoplasty, JAMA Otolaryngol. Head Neck Surg. 141 (2015) 704–709, https://doi.org/10.1001/ jamaoto.2015.1033. [8] S. Chan, G. Siou, A. Welch, S. Powell, Predictors for routine admission to paediatric intensive care for post-supraglottoplasty laryngomalacia patients, J. Laryngol. Otol. 131 (2017) 640–644, https://doi.org/10.1017/S0022215117001074. [9] D.W. Chen, Y.-C.C. Liu, Routine admission to step-down unit as an alternative to intensive care unit after pediatric supraglottoplasty, Int. J. Pediatr.
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