Effect of Intralesional Steroid Injections Among Patients with Acquired Laryngotracheal Stenosis Undergoing Endoscopic Balloon Dilation Using Pulmonary Function Tests

Abstract

Objectives: Laryngotracheal stenosis (LTS) is characterized by an abnormal decrease in the upper airway diameter. The pulmonary function test (PFT) is an effective adjunctive diagnostic tool for upper airway obstruction. LTS can be managed with either open surgery or less invasive endoscopic approaches, among which endoscopic balloon dilation is the main method; this may include concurrent intralesional steroid injection (ILSI), which has the potential of improving the outcomes. However, the effectiveness of ILSI is unclear. We aimed to compare the improvement in PFT parameters among patients with acquired LTS following endoscopic balloon dilation who received and did not receive ILSIs. We also compared the recurrence times and rates between the 2 patient cohorts. Methods: We retrospectively collected data regarding pre- and postoperative PFTs, as well as inter-dilation interval records, obtained between June 2015 and April 2020. Results: We included 34 patients with acquired etiologies. The most common cause of stenosis was intubation (52.9%), followed by trauma (29.4%). Further, 52.9% of the patients received ILSIs. Symptom recurrence was reported in 23 (67.6%) cases, with no significant between-group difference −0.1389 [95% confidence interval (CI): −0.4483, 0.1705]. The mean (standard deviation) duration of the first reintervention was 8.62 (8.00) and 7.38 (3.20) months among patients who did and did not receive ILSIs, respectively (mean difference −1.23, P = .614, 95% CI −6.30, 3.84). Conclusion: Our findings indicated that PFT parameters improved following endoscopic balloon dilation, with forced expiratory volume in 1 second being significantly higher with concurrent ILSI. However, there was no between-method difference in the treatment effectiveness. Additionally, the restenosis recurrence rate was consistent with that reported in the literature.

Keywords

intralesional steroid injection balloon dilation laryngotracheal stenosis pulmonary function test

Introduction

Laryngotracheal stenosis (LTS) is characterized by an abnormal decrease in the diameter of the upper airway between the larynx and carina. It can have idiopathic or acquired causes, such as endotracheal intubation, tracheostomy, trauma, inflammation, autoimmunity, and tumors.¹ LTS is diagnosed based on the patient’s clinical history and endoscopic examination, with radiographic imaging and pulmonary function tests (PFTs) being adjunctive diagnostic tools. Specifically, spirometry reflects the functional aspects rather than the anatomic severity of LTS.^1–4

LTS can be managed through the endoscopic or open surgical approach. The endoscopic approach may involve balloon dilation, cold or laser incision, adjunctive medication with wound-healing modifying agents such as mitomycin C (MMC), or intralesional steroid injections (ILSIs).¹ Endoscopic treatment is considered favorable for LTS with ongoing inflammation, lack of cartilage involvement, or idiopathic type. Incisions into the stenotic soft tissue scar are made through the whole thickness of the scar, saving the normal mucosal lumen. It is a less invasive procedure with lower morbidity compared to the open approach.⁵ Steroid use reduces scar proliferation, as well as collagen and glycosaminoglycan synthesis, and inhibits fibroblast growth, which allows scar softening.^6–8 Additionally, office-based and intraoperative administration of ILSIs has been found to improve the peak expiratory flow (PEF) by 23.1% (95% CI 6.4%, 39.8%) and 25.1% (95% CI 9.59%, 40.69%), respectively, in patients with idiopathic subglottic stenosis (SGS).⁹

The aforementioned management strategies seek to establish a patent airway without dyspnea. However, numerous patients develop restenosis requiring further interventions. A recent systematic review of endoscopic interventions for idiopathic SGS, including cold knife, laser, or dilation (balloon or rigid), in various combinations, with or without wound-healing modifying agents¹⁰ reported that the stenosis recurrence rate ranged from 40 to 100%, with no endoscopic intervention showing superiority. CO₂ laser incision monotherapy had the highest recurrence rate (100%) and shortest between-intervention interval (2 months). Contrastingly, ILSIs combined with rigid dilation showed the lowest recurrence rate (40%). Although combined therapy involving balloon dilation, MMC, and ILSIs resulted in a high recurrence rate of 80%, it showed the longest between-intervention interval (21.2 months). However, this was attributed to the prolonged follow-up duration for this intervention compared with other interventions. The existing literature shows the heterogeneity of different endoscopic interventions used in various combinations; these combinations have different recurrence rates with no intervention being obviously superior over the others.

Therefore, we aimed to compare the improvement in PFT parameters following endoscopic balloon dilation in patients with acquired LTS between those who did and those who did not receive ILSIs. Additionally, we aimed to compare the recurrence times and rates between the groups.

Patients and Methods

This retrospective study was conducted at King Saud University Medical City in Riyadh, Saudi Arabia, and approved by the Institutional Review Board of its College of Medicine (Project No. E-20-5029). We included patients aged >18 years with acquired LTS, who underwent endoscopic balloon dilation with or without concurrent ILSIs by all airway surgeons in the institute. Further, we excluded patients with idiopathic LTS, patients who underwent tracheostomy, and smokers to minimize confounding. Patient anonymity and consent were ensured, and data accessibility is available. We retrospectively collected data obtained between June 2015 and April 2020. Specifically, we collected information regarding demographic characteristics, chronic diseases, cause of stenosis, PFT parameters before and 1 month after the intervention, and between-intervention interval from electronic medical records of the e-SIHI hospital computerized program. The forced expiratory volume in 1 second (FEV1); PEF; FEV1/PEF; forced expiratory flow (FEF) at 25, 50, and 75% of vital capacity (FEF25, 50, and 75, respectively); maximum mid-expiratory flow (MMEF); and forced vital capacity (FVC) were collected from PFT reports. All patients underwent intraoperative endoscopic examination with the stenotic segment measured to obtain Cotton–Myer classification of the stenosis, length, distance from the vocal cords, dilation time, and type of anesthesia. A 15-mm balloon dilation catheter (CRE^®, Pulmonary Balloon Dilation Catheter, Boston Scientific Ltd., Cork, Ireland) was then inserted 3 times and dilated for 40 to 60 seconds depending on the degree of stenosis or until the oxygen saturation of the patient decreased. The decision to use ILSI and mitomycin C was based on primary surgeon preference and experience.

Statistical Analyses

Statistical analyses were performed using the SPSS program 26 (IBM Corp., Armonk, NY, USA). Between-group comparisons (with ILSIs vs without ILSIs) of continuous and categorical variables were performed using an independent-sample t-test and Fisher’s exact test, respectively. Paired-sample t-tests were used for within-group comparisons of pre- and postoperative measurements. Logistic regression analysis was used for predictors of improvement in PFT. The level of significance was α = .05 for all tests. The normality of continuous data was assessed using a Shapiro–Wilk test. Categorical variables were analyzed using the chi-squared test to determine statistical significance in cross-tabulations. In cases of continuous variables, an unpaired Student’s t-test was employed for normally distributed variables, while the Mann–Whitney U test was used for non-normally distributed variables.

Results

Table 1 presents the demographic characteristics, including the number of cases, sex, smoking status, lung condition, presence or absence of comorbidities, etiology of stenosis, symptom recurrence, type of anesthesia, dilation time, and Cotton–Meyer classification.

Table 1.

Demographic and Clinical Characteristics.

Variable	Patients who did not receive ILSIs (%)	Patients who received ILSIs (%)	Total	P-value
	16 (47.1)	18 (52.9)	34	—
Sex
Female	5 (31.3)	11 (61.1)	16	.082
Male	11 (68.8)	7 (38.9)	18	.082
Smoking status
No	13 (81.2)	18 (100.0)	31	.094
Former	3 (18.8)	0 (0.0)	3	.094
Lung disease (asthma/COPD)
No	14 (87.5)	17 (94.4)	31	.591
Yes	2 (12.5)	1 (5.6)	3	.591
Diabetes
No	15 (93.7)	13 (72.2)	28	.18
Yes	1 (6.3)	5 (27.8)	6	.18
Hypertension
No	12 (75.0)	18 (100.0)	30	.039
Yes	4 (25.0)	0 (0.0)	4	.039
Ischemic heart disease
No	15 (93.7)	18 (100.0)	33	.471
Yes	1 (6.3)	0 (0.0)	1	.471
Rheumatological disease
No	15 (93.7)	13 (72.2)	28	.34
Yes	1 (6.3)	5 (27.8)	6	.34
GERD/LPR
No	16 (100.0)	18 (100.0)	34	—
pH monitoring
No	16 (100.0)	18 (100.0)	34	—
Diagnosis
SGS	13 (81.2)	16 (88.9)	29	.648
TS	3 (18.8)	2 (11.1)	5	.648
Etiology
Acquired	16 (100.0)	18 (100.0)	34	—
Cause of stenosis
Intubation	10 (62.5)	8 (44.4)	18	.334
Trauma	5 (31.2)	5 (27.8)	10
Rheumatology	1 (6.3)	5 (27.8)	6
MMC application
No	1 (6.3)	4 (22.2)	5	.34
Yes	15 (93.7)	14 (77.8)	29	.34
Symptom recurrence
No	4 (25.0)	7 (38.9)	11	.477
Yes	12 (75.0)	11 (61.1)	23	.477
Type of anesthesia
Spontaneous ventilation	16 (100)	18 (100)	34	—
Dilation time
40 s	16 (100)	18 (100)	34	—
Cotton–Myer classification
Grade 1	3 (18.8)	7 (38.9)	10	.437
Grade 2	7 (43.8)	6 (33.3)	13
Grade 3	6 (37.5)	5 (27.8)	11

Abbreviations: COPD, chronic obstructive pulmonary disease; GERD, gastroesophageal reflux disease; ILSI, intralesional steroid injection; LPR, laryngopharyngeal reflux; MMC, mitomycin C; SGS, subglottic stenosis; TS, tracheal stenosis.

The group of patients who received ILSIs consisted of 18 individuals, 11 (61.1%) females and 7 (38.9%) males. In contrast, among the 16 patients who did not receive ILSIs, 5 (31.3%) were female and 11 (68.8%) were male. However, the difference in the proportion of males and females between these 2 groups was not statistically significant.

SGS and tracheal stenosis (TS) were diagnosed in 29 (85.3%) and 5 (14.7%) patients, respectively. The main cause of stenosis was intubation (52.9%), followed by trauma (29.4%) and rheumatological causes (17.7%).

ILSIs and MMC were administered to 52.9 and 85.3% of patients, respectively. Among the 18 patients who received ILSIs, symptom recurrence was reported in 11 cases (61.1%). In the group of 16 patients who did not receive ILSIs, symptom recurrence was reported in 12 cases (75.0%). The overall recurrence rate was 67.6%. However, there was no significant difference in the proportions of symptom recurrence between the 2 groups. The calculated between-group difference in the proportion of symptom recurrence was −0.1389 [95% confidence interval (CI): −0.4483, 0.1705].

All patients (n = 34) received spontaneous ventilation, among which 18 received ILSIs and 16 did not receive ILSIs. Similarly, the dilation time of all patients was 40 seconds. According to Cotton–Myer classification, 10 patients were in grade 1, 13 in grade 2, and 11 in grade 3 categories. No significant differences were observed between those who received ILSIs and those who did not receive ILSIs (P = .437).

Patients who did not receive ILSIs were significantly taller than those who received ILSIs (165.22 cm ± 7.42 vs 158.94 cm ± 9.46; P = .041). No significant between-group differences in age, weight, percentage of stenosis, stenosis length, or distance of stenosis from the vocal cords were observed. The mean (standard deviation) time to first reintervention was 8.62 (8.00) and 7.38 (3.20) months for patients who did and those who did not receive ILSIs, respectively (P =.614, 95% CI −6.30, 3.84; Table 2).

Table 2.

Summary Statistics of Demographic and Clinical Characteristics.

Variable	Group				MD	95% CI	P-value
	Patients who did not receive ILSIs		Patients who received ILSIs
	M	SD	M	SD
Age (y)	34.38	8.37	38.61	11.93	−4.24	(−11.52, 3.05)	.245
Weight (kg)	71.24	20.78	64	8.2	7.24	(−4.36, 18.84)	.207
Height (cm)	165.22	7.42	158.94	9.46	6.27	(0.28, 12.27)	.041
Stenosis (%)	59.55	10.99	61.22	12.64	−1.68	(−12.77, 9.42)	.754
Stenosis vertical length (cm)	1.23	0.62	1.27	0.65	−0.04	(−0.82, 0.74)	.916
Stenosis distance from the vocal cord (cm)	2.2	0.84	1.99	0.75	0.21	(−0.71, 1.14)	.622
First follow-up (mo)	1.13	0.99	0.74	0.73	0.39	(−0.21, 0.99)	.198
First reintervention (mo)	7.38	3.2	8.62	8	−1.23	(−6.30, 3.84)	.614

Abbreviations: CI, confidence interval; ILSI, intralesional steroid injection; MD, mean difference; SD, standard deviation.

Tables 3 and 4 show the pre- and postoperative PFT parameters, respectively. Patients who did not receive ILSIs had significantly higher preoperative FEV1 than those who received ILSIs (2.09 ± 0.58 vs 1.59 ± 0.72, mean difference 0.50, P = .035, 95% CI 0.04, 0.96). There were no significant between-group differences in the preoperative PEF; FEV1/PEF; 25%, 50%, and 75% FEF; MMEF; and FVC. Moreover, there were no significant between-group differences in all postoperative measurements (P > .05).

Table 3.

Between-Group Comparisons of Preoperative PFT Parameters.

Variable	Group				MD	95% CI	t	P-value
	Patients who did not receive ILSIs		Patients who received ILSIs
	M	SD	M	SD
FEV1	2.09	0.58	1.59	0.72	0.5	(0.04, 0.96)	2.2	.035
PEF	2.75	1.5	2.65	2.6	0.1	(−1.41, 1.61)	0.14	.893
FEV1/PEF	0.84	0.18	0.79	0.24	0.05	(−0.10, 0.20)	0.71	.48
FEF25	2.68	1.5	2.01	1.18	0.67	(−0.27, 1.60)	1.44	.158
FEF50	2.38	1.16	1.82	1.08	0.56	(−0.23, 1.34)	1.45	.158
FEF75	1.37	0.41	1.21	0.53	0.16	(−0.18, 0.50)	0.97	.338
MMEF	2.07	0.68	1.7	0.92	0.37	(−0.21, 0.94)	1.31	.201
FVC	2.71	0.66	2.43	0.8	0.28	(−0.23, 0.80)	1.12	.269

Abbreviations: CI, confidence interval; FEF25, FEF50, and FEF75: forced expiratory flow from 25%, 50%, and 75% of vital capacity, respectively; FEV1, forced expiratory volume in 1 second; FVC, forced vital capacity; ILSI, intralesional steroid injection; MD, mean difference; MMEF, maximum mid-expiratory flow; PEF, peak expiratory flow; PFT, pulmonary function test; SD, standard deviation; t, statistic.

Table 4.

Between-Group Comparisons of Postoperative PFT Parameters.

Variable	Group				MD	95% CI	t	P-value
	Patients who did not receive ILSIs		Patients who received ILSIs
	M	SD	M	SD
FEV1	2.29	0.73	2.26	0.73	0.03	(−0.48, 0.54)	0.12	.908
PEF	4.33	2.43	3.78	1.64	0.55	(−0.89, 1.98)	0.78	.443
FEV1/PEF	0.63	0.23	0.66	0.21	−0.03	(−0.18, 0.12)	−0.4	.689
FEF25	4.22	2.47	3.75	1.63	0.47	(−0.98, 1.91)	0.66	.515
FEF50	3.01	1.25	2.91	1.16	0.1	(−0.75, 0.94)	0.24	.813
FEF75	1.25	0.45	1.4	0.53	−0.15	(−0.50, 0.19)	−0.91	.371
MMEF	2.47	0.92	2.53	0.98	−0.06	(−0.73, 0.61)	−0.19	.854
FVC	2.91	0.69	2.77	0.74	0.14	(−0.37, 0.64)	0.56	.582

Abbreviations: CI, confidence interval; FEF25, FEF50, and FEF75: forced expiratory flow at 25, 50, and 75% of vital capacity, respectively; FEV1, forced expiratory volume in 1 s; MD, mean difference; FVC, forced vital capacity; ILSI, intralesional steroid injection; MMEF, maximum mid-expiratory flow; PEF, peak expiratory flow; PFT, pulmonary function test; SD, standard deviation; t, statistic.

Among patients who did not receive ILSIs, compared with the preoperative values, the postoperative PEF (M_pre = 2.75 ± 1.50 vs M_post = 4.33 ± 2.43) and FEF25 (M_pre = 2.68 ± 1.50 vs M_post = 4.22 ± 2.47) were significantly higher (P = .005 and .008, respectively), while the postoperative FEV1/PEF values (M_pre = 0.84 ± 0.18 vs M_post = 0.63 ± 0.23) were significantly lower (P = .008). There were no significant within-group differences in the FEV1, FEF50, FEF75, MMEF, or FVC (P = .139, 0.068, .379, .052 and .209, respectively; Table 5).

Table 5.

Within-Group Comparisons (Pre- and Post-Surgery Measurements).

Group	MD	Std. error	95% CI		t	df	P-value
Group	MD	Std. error	Lower	Upper	t	df	P-value
ILSIs not used
FEV1	−0.2	0.12	−0.46	0.07	−1.56	15	.139
PEF	−1.58	0.48	−2.59	−0.56	−3.32	15	.005
FEV1/PEF	0.21	0.07	0.06	0.36	3.05	15	.008
FEF25	−1.54	0.49	−2.58	−0.5	−3.15	15	.007
FEF50	−0.63	0.32	−1.31	0.05	−1.97	15	.068
FEF75	0.13	0.14	−0.17	0.42	0.91	15	.379
MMEF	−0.41	0.19	−0.82	0	−2.11	15	.052
FVC	−0.19	0.15	−0.51	0.12	−1.31	15	.209
ILSIs used
FEV1	−0.66	0.24	−1.16	−0.16	−2.8	17	.012
PEF	−1.13	0.8	−2.82	0.56	−1.41	17	.176
FEV1/PEF	0.13	0.07	−0.01	0.27	1.96	17	.067
FEF25	−1.74	0.38	−2.54	−0.93	−4.56	17	<.001
FEF50	−1.09	0.34	−1.81	−0.36	−3.17	17	.006
FEF75	−0.19	0.22	−0.65	0.27	−0.87	17	.399
MMEF	−0.84	0.32	−1.51	−0.16	−2.63	17	.018
FVC	−0.34	0.17	−0.7	0.02	−2.01	17	.06

Abbreviations: CI, confidence interval; df degrees of freedom; FEF25, FEF50, and FEF75, forced expiratory flow at 25, 50, and 75% of vital capacity, respectively; FEV1, forced expiratory volume in 1 s; MD, mean difference; FVC, forced vital capacity; MMEF, maximum mid-expiratory flow; PEF, peak expiratory flow; Std., standard deviation standard; t, statistic.

Table 5 shows the results of within-group comparisons of pre- and postoperative measurements.

Among patients who received ILSIs, compared with the preoperative values, the postoperative FEV1 (M_pre = 1.59 ± 0.72 vs M_post = 2.26 ± 0.73), FEF25 (M_pre = 2.01 ± 1.18 vs M_post = 3.75 ± 1.63), FEF50 (M_pre = 1.82 ± 1.08 vs M_post = 2.91 ± 1.16), and MMEF (M_pre = 1.70 ± 0.92 vs M_post = 2.53 ± 0.98) were significantly higher (P = .012, .001, .006, and .018, respectively).

The pre-post difference in PFT parameters was calculated by subtracting the pre-PFT values from the post-PFT values (Table 6).

Table 6.

Comparison of the Pre-Post Differences in PFT Between Groups.

Variable	Group				MD	95% CI	t	P-value
	Patients who did not receive ILSIs		Patients who received ILSIs
	M ± SD	Median (Min, Max)	M ± SD	Median (Min, Max)
FEV1 diff	0.19 ± 0.5	0.15 (−0.94, 1.3)	0.67 ± 1	0.28 (−1.07, 2.63)	0.49	(−0.06, 1.04)	1.83	.079^#
PEF diff	1.56 ± 1.88	1.6 (−0.9, 4.37)	1.2 ± 3.46	1.64 (−11.1, 5.13)	—	—	U = 156.5	.666^@
FEV1/PEF diff	−0.21 ± 0.28	−0.18 (−0.58, 0.25)	−0.13 ± 0.29	−0.16 (−0.46, 0.78)	—	—	U = 163.0	.512^@
FEF25 diff	1.52 ± 1.93	1.34 (−0.9, 4.82)	1.71 ± 1.6	1.65 (−1.12, 5.16)	0.19	(−1.04, 1.43)	0.32	.751^#
FEF50 diff	0.68 ± 1.25	0.58 (−1.52, 2.88)	1.07 ± 1.46	0.6 (−1.06, 4.04)	0.4	(−0.56, 1.35)	0.84	.406^#
FEF75 diff	−0.09 ± 0.58	−0.1 (−1.1, 1.01)	0.18 ± 0.93	−0.02 (−1.65, 1.68)	0.27	(−0.26, 0.81)	1.04	.307^#
MMEF diff	0.46 ± 0.79	0.25 (−0.86, 1.83)	0.83 ± 1.35	0.47 (−1.06, 3.67)	0.37	(−0.40, 1.14)	0.98	.334^#
FVC diff	0.16 ± 0.6	0.05 (−0.73, 1.64)	0.36 ± 0.71	0.31 (−1.59, 1.3)	0.2	(−0.27, 0.66)	0.87	.393^#

Abbreviations: CI, confidence interval; FEV1, forced expiratory volume in 1 s; FEF25, FEF50, and FEF75: forced expiratory flow at 25, 50, and 75% of vital capacity, respectively; FVC, forced vital capacity; ILSI, intralesional steroid injection; MD, mean difference; MMEF, maximum mid-expiratory flow; PEF, peak expiratory flow; PFT, pulmonary function test; SD, standard deviation; t, statistic.

unpaired Student’s t-test.

Mann–Whitney U test.

Except for the PEF diff variable, all other PFT parameters showed a higher mean difference in patients who received ILSIs than in those who did not. However, this difference was not statistically significant.

Logistic regression analysis was conducted to determine predictors for PFT improvement, which was defined as the difference between the pre- and postoperative FEV1 values. The median difference in FEV1 values was calculated, and values equal to or above the median value were considered to show improvement in PFT. None of the predictive variables included in the regression model showed statistical significance (Table 7).

Table 7.

Logistic Regression Analysis for Predictors of Improvement in PFT.

Variable	B	P-value	OR (95% CI)
Diabetes mellitus	−0.593	.73	0.553 (0.019-15.960)
Hypertension	−1.821	.203	0.162 (0.010-2.676)
Ischemic heart disease	−19.917	1	0.000 (0.000-NA)
Rheumatological disorder	−1.451	.373	0.234 (0010-5.709)
Lung disorder	−1.565	.257	0.209 (0.014-3.130)
ILSI	−0.858	.356	0.424 (0.069-2.625)
MMC application	0.02	.985	1.021 (0.118-8.789)
Constant	25.076	1

Abbreviations: B, standard coefficient; ILSI, intralesional steroid injection; MMC, mitomycin C; NA, not available; OR, Odds ratio; PFT, pulmonary function test.

Discussion

We observed postoperative improvements after endoscopic balloon dilation in several PFT parameters, including the FEV1, PEF, FEV1/PEF, FEF25, FEF50, and MMEF, consistent with previous related reports.^3,11,12 Additionally, the FEV1 was significantly higher under ILSI administration, which is consistent with that observed in the aforementioned reports.

In patients with acquired SGS, including those with an idiopathic etiology, endoscopic dilation improves PFT outcomes, such as the FEV1, PEF, FEV1/PEF, FEF25, FEF50, and MMEF.^13–15 Hseu et al. reported that PEF, total peak flow, and FEV1/PEF were the most sensitive and specific parameters for monitoring the effectiveness of an intervention.¹⁶ Similarly, our findings showed improvement in FEV1, FEF25, FEF50, and MMEF among patients who received ILSI, but without statistical significance. The significant improvement observed in PEF and FEF25 in patients who did not receive ILSI might be due to the selection of patients with less severe SGS.

Moreover, the present study showed that in terms of the pre- and postoperative PFT difference, all PFT parameters except PEF showed improvements in mean difference in patients who received ILSIs compared to those who did not. However, this still did not suggest a favorable intervention (all P > .05). Other studies have evaluated the efficacy of PEF as a reliable predictor of disease worsening and the need for an intervention. However, PEF was shown to be less useful than other parameters for the initial diagnosis of SGS.^14,17,18

The lack of improvement in PFT using balloon dilation with concurrent ILSI compared to simple dilation could be due to disease etiology or patients’ comorbidity.¹⁹ Our results did not show any factor that predicts PFT improvement. In our study, the mean duration until the first postoperative follow-up visit was 0.74 to 1.13 months. Moreover, no significant between-group difference in the mean interval to the first intervention due to symptom recurrence was observed.

Consistent with our study, Feinstein et al. reported no significant difference in the mean between-intervention interval according to applied adjuvant measures among patients with SGS of various etiologies.²⁰ Additionally, Hseu et al. reported no significant difference in the mean between-intervention interval.¹⁶ Moreover, office-based and intraoperative administration of ILSIs has been observed to extend the surgery-free post-intervention interval.^21–23 Another study showed that among patients with autoimmune, idiopathic, and traumatic SGS, 68.9% showed improved endoscopic dilation following ILSI administration; however, there were no significant differences in the number of reinterventions required to achieve such an outcome.²⁴

There was no significant difference in the recurrence rate between patients who did or did not receive ILSIs (61.1% vs 75%, P = .477). The overall recurrence rate in our study was 67.6% (95% CI: −0.4483, 0.1705), with previously reported values ranging from 40% to 80%.¹⁰ A randomized controlled trial reported that steroid inhalation improved PFT parameters; however, the recurrence rate was comparable between the inhaled steroid and control groups.²⁵

Limitations and Recommendations

This study had some limitations. First, this was a small-scale retrospective study. Second, the wide range of involved anatomical areas in patients with SGS and TS makes the data broad and vague. Finally, an additional objective measure other than PFT is required to assess surgical outcomes. A large-scale randomized controlled study is warranted to validate our findings.

Conclusion

PFT parameters improved following endoscopic balloon dilation with FEV1 being significantly high with concurrent ILSI. There was no between-method difference in the treatment effectiveness, although almost all PFT parameters showed a higher mean difference in patients who received ILSIs than in those who did not, with statistically nonsignificant results. Additionally, the restenosis recurrence rate was consistent with that reported in the literature, indicating that the disease is progressive and inflammatory, with no standardized treatment established yet.

Although patients with LTS show improvement and symptom-free intervals after endoscopic management, otolaryngologists still face difficulties in choosing the optimal intervention for these patients.

Footnotes

Acknowledgements

We would like to thank and appreciate the support provided by the Deanship of Scientific Research, King Saud University. We are also grateful to Editage () for the English editing, scientific review, and constructive feedback.

Declaration of Conflicting Interests

The author(s) declared no potential conflicts of interest with respect to the research, authorship, and/or publication of this article.

Funding

The author(s) received no financial support for the research, authorship, and/or publication of this article.

ORCID iDs

Nada Alouda

Nasser Almujaiwel

Abdulaziz Alrabiah

References

Raman

Chatterjee

Alzghoul

, et al. A bronchoscopic approach to benign subglottic stenosis. SAGE Open Med Case Rep. 2017;5:2050313X1771315. doi:10.1177%2F2050313X17713151

Nikolovski

Kopacheva-Barsova

Pejkovska

. Laryngotracheal stenosis: a retrospective analysis of their aetiology, diagnose and treatment. Open Access Maced J Med Sci. 2019;7(10):1649-1656. doi:10.3889%2Foamjms.2019.339

Abdullah

Alrabiah

Habib

, et al. The value of spirometry in subglottic stenosis. Ear, Nose Throat J. 2019;98(2):98-101. doi:10.1177/0145561318823309

Aboussouan

Stoller

. Diagnosis and management of upper airway obstruction. Clin Chest Med. 1994;15(1):35-53. doi:10.1016/S0272-5231(21)01054-6

Roediger

Orloff

Courey

. Adult subglottic stenosis: management with laser incisions and mitomycin-C. Laryngoscope. 2008;118(9):1542-1546. doi:10.1097/mlg.0b013e318179247a

Boyadjiev

Popchristova

Mazgalova

. Histomorphologic changes in keloids treated with Kenacort. J Trauma. 1995;38(2):299-302. doi:10.1097/00005373-199502000-00030

Cruz

Korchin

. Inhibition of human keloid fibroblast growth by isotretinoin and triamcinolone acetonide in vitro. Ann Plast Surg. 1994;33(4):401-405. doi:10.1097/00000637-199410000-00007

Reish

Eriksson

. Scar treatments: preclinical and clinical studies. J Am Coll Surg. 2008;206(4):719-730. doi:10.1016/j.jamcollsurg.2007.11.022

Franco

Jr Husain

Reder

Paddle

. Awake serial intralesional steroid injections without surgery as a novel targeted treatment for idiopathic subglottic stenosis. Laryngoscope. 2018;128(3):610-617. doi:10.1002/lary.26874

10.

Lavrysen

Hens

Delaere

Meulemans

. Endoscopic treatment of idiopathic subglottic stenosis: a systematic review. Front Surg. 2020;6:75. doi:10.3389%2Ffsurg.2019.00075

11.

Alrabiah

Almohanna

Aljasser

, et al. Utility of spirometry values for evaluating tracheal stenosis patients before and after balloon dilation. Ear, Nose, Throat J. 2022;101(2):NP62-NP67. doi:10.1177/0145561320936968

12.

Tie

Buckmire

Shah

. The role of spirometry and dyspnea index in the management of subglottic stenosis. Laryngoscope. 2019;130(12):2760–2766. doi:10.1002/lary.28337

13.

Kraft

Sykes

Palmer

Schindler

. Using pulmonary function data to assess outcomes in the endoscopic management of subglottic stenosis. Ann Otol Rhinol Laryngol. 2015;124(2):137–142. doi:10.1177/0003489414548915

14.

Carpenter

Ferrante

Bakos

Clary

Gelbard

Daniero

. Utility of routine spirometry measures for surveillance of idiopathic subglottic stenosis. JAMA Otolaryngol Head Neck Surg. 2019;145(1):21–26. doi:10.1001/jamaoto.2018.2717

15.

Alrabiah

Jomah

Alduraywish

, et al. Significance of the pulmonary function test for the diagnosis of subglottic stenosis: a systematic review. B-ENT. 2020;16(4):233–239. doi:10.5152/B-ENT.2021.20056

16.

Hseu

Benninger

Haffey

Lorenz

. Subglottic stenosis: a ten-year review of treatment outcomes. Laryngoscope. 2014;124(3):736-741. doi:10.1002/lary.24410

17.

Crosby

McWhorter

McDaniel

Kunduk

Adkins

. Predicting need for surgery in recurrent laryngotracheal stenosis using changes in spirometry. Laryngoscope. 2021;131(10):2199-2203. doi:10.1002/lary.29239

18.

Nouraei

Patel

, et al. Diagnosis of laryngotracheal stenosis from routine pulmonary physiology using the expiratory disproportion index. Laryngoscope. 2013;123(12):3099-3104. doi:10.1002/lary.24192

19.

Gelbard

Francis

Sandulache

Simmons

Donovan

Ongkasuwan

. Causes and consequences of adult laryngotracheal stenosis. Laryngoscope. 2015;125(5):1137-1143. doi:10.1002/lary.24956

20.

Feinstein

Goel

Raghavan

, et al. Endoscopic management of subglottic stenosis. JAMA Otolaryngol Head Neck Surg. 2017;143(5):500-505. doi:10.1001/jamaoto.2016.4131

21.

Shabani

Hoffman

Brand

Dailey

. Endoscopic management of idiopathic subglottic stenosis. Ann Otol Rhinol Laryngol. 2017;126(2):96–102. doi:10.1177/0003489416675357

22.

Bertelsen

Shoffel-Havakuk

O’Dell

Johns

Reder

. Serial in-office intralesional steroid injections in airway stenosis. JAMA Otolaryngol Head Neck Surg. 2018;144(3):203–210. doi:10.1001/jamaoto.2017.2800

23.

Pan

Rosow

. Office-based corticosteroid injections as adjuvant therapy for subglottic stenosis. Laryngoscope Investig Otolaryngol. 2019;4(4):414-419. doi:10.1002/lio2.284

24.

Wierzbicka

Tokarski

Puszczewicz

Szyfter

. The efficacy of submucosal corticosteroid injection and dilatation in subglottic stenosis of different aetiology. J Laryngol Otol. 2016;130(7):674-679. doi:10.1017/S0022215116001122

25.

Alrabiah

Alsayed

Aljasser

, et al. Effect of inhaled fluticasone propionate on laryngotracheal stenosis after balloon dilation: a randomized controlled trial. Eur Arch Oto-Rhino-Laryngol. 2021;278(5):1505-1513. doi:10.1007/s00405-021-06622-x