Recurrence Following Endoscopic Laser Wedge Excision and Triple Medical Therapy for Idiopathic Subglottic Stenosis

Laser Versus Cold Steel for Endoscopic Management of Subglottic Stenosis

OBJECTIVE

Endoscopic management of subglottic stenosis (SGS) includes a wide range of techniques. This 17-year review compares treatment outcomes between carbon dioxide (CO2) laser and cold steel.

STUDY DESIGN

Retrospective chart review.

SETTING

Single tertiary care center.

METHODS

A chart review was performed for all patients undergoing endoscopic treatment of SGS at Cleveland Clinic between July 12, 2000 and September 1, 2017. Data collected included demographics, stenosis etiology, stenosis severity, comorbidities, treatment modality, and airway procedure history. The primary endpoint was repeated treatment-free survival (RTFS) within 2 years using a Kaplan-Meier analysis and Cox proportional hazard model.

RESULTS

A total of 139 patients (median [interquartile range] aged 48.7 [37.8, 57.0] years; 83.4% female) were included in the analysis, with etiologies including idiopathic (56.8%), granulomatosis with polyangiitis (25.2%), and intubation (16.5%). All patients underwent either cold steel (107 patients) or CO2 laser (32 patients) lysis of stenosis with concurrent dilation. RTFS within 2 years was 50.2% for CO2 laser and 31.9% for cold steel (hazard ratio [HR] and 95% confidence interval [CI]: 1.69, 0.96-2.97, P = .07). In patients with no prior airway procedures, there was no difference in RTFS between laser and cold knife (P = .41). However, in patients with prior airway procedures, RTFS was significantly greater in the laser group, even after adjusting for age, smoking history, and stenosis etiology (50.0% vs 16.8%, adjusted HR and CI: 2.82, 1.14-6.98, P = .025).

CONCLUSION

Endoscopic lysis of SGS with CO2 laser should be considered in revision cases.

Impact of Procedural Variation in Endoscopic Dilation for Idiopathic Subglottic Stenosis

OBJECTIVES

A small number of Idiopathic subglottic stenosis (iSGS) patients are treated at institutions across the country. Divergence in operative techniques for endoscopic dilation (ED) of iSGS has been anecdotally recognized but not formally characterized. Additionally, the relationship between procedural variation and clinical outcome has not been studied.

METHODS

Secondary analysis of the NoAAC iSGS1000 cohort investigated variation in procedural techniques and treatment outcomes in patients treated with ED across high-enrolling treatment centers (enrolled >10 patients in PR-02 trial).

RESULTS

Thirteen NoAAC centers each enrolled >10 patients treated with ED for a total of 281 subjects. There was significant variation in procedural details and rate of recurrence among institutions. Hierarchal cluster analysis revealed significant heterogeneity among institutions and clusters in all procedural variables. However, analysis demonstrated a transient delay in disease recurrence in cluster 2 which disappeared with longer longitudinal follow-up. Patient-reported outcome and peak expiratory flow data supported the potential benefit of the technical variation in Cluster 2. Distinct to cluster 2, however, was routine use of adjuvant triple medical therapy (proton pump inhibitor (PPI), antibacterial agent, and steroid inhaler).

CONCLUSIONS

Both outcome and procedural technique vary among centers employing ED to treat iSGS. A transient delay in recurrence was observed among centers that routinely prescribed adjuvant medical therapy (antibiotic, inhaled corticosteroid, and PPI) to iSGS patients after endoscopic dilation, which was further supported by patient-reported data and peak expiratory flow data. Prospective studies are needed to understand the effects of adjuvant medical therapy on recurrence after endoscopic dilation.

LEVEL OF EVIDENCE

4 Laryngoscope, 134:3260-3266, 2024.

Symptom-Free Intervals Following Laser Wedge Excision for Recurrent Idiopathic Subglottic Stenosis

OBJECTIVE

Analyze the duration of symptom-free intervals following laser wedge excision (LWE) for recurrent idiopathic subglottic stenosis (iSGS). Secondary aim includes evaluating the influence of patient-related or disease factors.

STUDY DESIGN

Retrospective review.

SETTING

Tertiary center.

METHODS

Review of iSGS patients who underwent LWE between 2002 and 2021. LWE patients without prior airway surgery were labeled LWE primary (LWEP) and those with prior history of dilation were labeled LWE secondary (LWES). A conditional frailty repeated events model was used to analyze the median time to recurrence (MTR) for each nth recurrence. Secondary analysis included stratification by use of medical therapy and initial preoperative characteristics of scar (Myer-Cotton grade, distance between the glottis and superior-most aspect of scar, DGS; length of scar, DL).

RESULTS

Two hundred and ten iSGS patients underwent LWE (131 LWEP, 79 LWES). The proportion of patients experiencing at least 1, 3, 6, and 12 recurrences, respectively, was 68.0% (n = 143), 40.7% (n = 85), 20.0% (n = 42), and 5.2% (n = 11). There was exponential time-shortening from the 1st to 12th recurrence (P < .0001). While MTR was 4.1 years after the first LWE, this fell to 2.8, 1.7, 1.0, and 0.7 years for the 2nd, 3rd, 6th, and 12th recurrences. Furthermore, LWEP patients experienced longer MTR than LWES counterparts within the first 6 recurrences (P < .01). There was no significant relationship between intersurgical interval and medication adherence, DL, DGS, or grade for recurrences beyond the first (P = .207, P = .20, P = .43, P = .16).

CONCLUSION

Symptom-free intervals in iSGS shorten with each subsequent recurrence and LWE. The difference in MTR between LWEP and LWES groups was significant within the first 6 recurrences with LWEP having longer MTR.

LEVEL OF EVIDENCE: 3

An Ovine Model Yields Histology and Gene Expression Changes Consistent with Laryngotracheal Stenosis

OBJECTIVES

Animal models for laryngotracheal stenosis (LTS) are critical to understand underlying mechanisms and study new therapies. Current animal models for LTS are limited by small airway sizes compared to human. The objective of this study was to develop and validate a novel, large animal ovine model for LTS.

METHODS

Sheep underwent either bleomycin-coated polypropylene brush injury to the subglottis (n = 6) or airway stent placement (n = 2) via suspension microlaryngoscopy. Laryngotracheal complexes were harvested 4 weeks following injury or stent placement. For the airway injury group, biopsies (n = 3 at each site) were collected of tracheal scar and distal normal regions, and analyzed for fibrotic gene expression. Lamina propria (LP) thickness was compared between injured and normal areas of trachea.

RESULTS

No mortality occurred in sheep undergoing airway injury or stent placement. There was no migration of tracheal stents. After protocol optimization, LP thickness was significantly increased in injured trachea (Sheep #3: 529.0 vs. 850.8 um; Sheep #4: 933.0 vs. 1693.2 um; Sheep #5: 743.7 vs. 1378.4 um; Sheep #6: 305.7 vs. 2257.6 um). A significant 62-fold, 20-fold, 16-fold, 16-fold, and 9-fold change of COL1, COL3, COL5, FN1, and TGFB1 was observed in injured scar specimen relative to unaffected airway, respectively.

CONCLUSION

An ovine LTS model produces histologic and transcriptional changes consistent with fibrosis seen in human LTS. Airway stent placement in this model is safe and feasible. This large airway model is a reliable and reproducible method to assess the efficacy of novel LTS therapies prior to clinical translation.

LEVEL OF EVIDENCE

N/A Laryngoscope, 2024.

The Safety and Efficacy of the 445-nm Blue Laser for Operative Management of Benign Nonvascular Laryngeal Lesions

The 445-nm blue laser combines the features of photocoagulative vascular lasers and cutting lasers in one device. The purpose of the present study was to evaluate the safety and efficacy of the 445-nm blue laser for the treatment of benign laryngeal pathologies, other than vascular lesions. Outcomes were compared to those when already-established therapies were used.

METHODS

Adult voice center patients who underwent surgical intervention for vocal fold (VF) mass, VF scar, laryngeal stenosis, laryngeal web, or Reinke's edema were included in this retrospective study. Outcomes were compared to those achieved when traditional treatment modalities were used, including cold steel, CO2 laser, potassium-titanyl-phosphate (KTP) laser, and coblator. Strobovideolaryngoscopy footage was evaluated using a previously described model at four time points: postoperative visit #1: 1-14 days, postoperative visit #2: 30-60 days, postoperative visit #3: 61-365 days, postoperative visit #4: >365 days.

RESULTS

Eighty cases using the blue laser and 153 controls (n = 78 cold steel, n = 51 KTP laser, n = 22 CO2 laser, n = 2 coblator) were included in this study. Procedures performed using blue laser included VF mass excision (n = 45), VF scar reduction (n = 16), laryngeal stenosis resection/repair (n = 25), laryngeal web excision (n = 7), and reduction of Reinke's edema (n = 1). On postoperative strobovideolaryngoscopy examination, the surgical objective score did not differ significantly between the blue laser cohort and all controls at any postoperative visit. VF edema did not differ significantly between the blue laser cohort and all controls at any postoperative visit. VF hemorrhage scores were significantly lower in the blue laser cohort compared to all controls at the first postoperative visit, but hemorrhage had resolved almost entirely by the second postoperative visit in all groups. Postoperative VF stiffness was worse in the blue laser group at the third postoperative visit compared to controls, but both groups had improved to similar levels by the fourth postoperative visit. The rate of lesion recurrence (24.29% versus 17.19%) did not differ significantly between the blue laser cohort and controls on multivariate analysis (Odds ratio [OR] = 1.081 [0.461-2.536]). The complication rate (12.50% versus 10.46%) did not differ significantly between the blue laser cohort and all controls on multivariate analysis (OR = 0.992 [0.375-2.624]). The blue laser was associated with a lower rate of revision surgery (30.00% versus 34.64%) on multivariate analysis (OR = 0.380 [0.168-0.859]).

CONCLUSION

The 445-nm blue laser is safe and effective for the management of benign laryngeal lesions. It has efficacy and safety similar to those of traditional treatment modalities (including cold steel, CO2 laser, and KTP laser). Use of the blue laser may lead to lower rates of early postoperative hemorrhage and revision surgery. No adverse effects attributed directly to the use of the blue laser were observed in this study. Further research is encouraged to confirm or refute these findings.

Laryngotracheal Reconstruction for Subglottic and Tracheal Stenosis

Laryngotracheal stenosis is the common endpoint for any process that results in the narrowing of the airway at the level of the glottis, subglottis, or trachea. Although endoscopic procedures are effective in opening the airway lumen, open resection and reconstruction can be necessary to reconstitute a functional airway. When resection and anastomosis are insufficient due to extensive length or location of the stenosis, autologous grafts can be used to expand the airway. Future directions in airway reconstruction include tissue engineering and allotransplantation.

Proximal Scar Progression in Idiopathic Subglottic Stenosis After Wedge Excision: Does it Happen?

OBJECTIVE

To compare the incidence of glottic stenosis in idiopathic subglottic stenosis (iSGS) patients with no prior surgical intervention to those with a history of endoscopic dilation and characterize the incidence of glottic involvement, changes in scar length, and progression of scar toward glottis following laser wedge excision (LWE).

METHODS

A retrospective review of iSGS patients who underwent LWE between 2002 and 2021 was performed. Patients without prior airway surgery were labeled LWE primary (LWEP) and operative findings for LWEP patients were reviewed for glottic involvement, scar length (D_L ), and distance from the glottis to superior-most aspect of scar (D_GS ). Rates (in mm/procedure) of D_ΔL , reflecting an increase in length, and D_-ΔGS , reflecting proximal migration, were calculated by dividing D_ΔL and D_-ΔGS by the number of LWE procedures.

RESULTS

213 iSGS patients underwent LWE, with 132 being LWEP patients. LWEP had a lower incidence of baseline glottic involvement (n = 6, 4.5%) than LWE secondary (LWES; n = 6, 7.5%). Four new cases of glottic involvement were noted in LWEP patients following LWE, with only one being clinically significant resulting in permanently decreased vocal fold mobility. With each procedure, scar length increased by 1.0 mm and D_GS decreased by 0.7 mm, reflecting a migration or decrease in D_GS of 9.5% with each procedure with respect to initial D_GS . Overall rates of glottic stenosis following operations were similar between LWEP and LWES cohorts, 7.6% and 7.5% respectively.

CONCLUSION

There appears to be a low risk of glottic involvement resulting from the LWE procedure in iSGS patients.

LEVEL OF EVIDENCE

4 Laryngoscope, 133:875-882, 2023.