Flexible bronchoscopy interventional therapy for central airway stenosis after resection of endobronchial schwannoma: a case report

Introduction

Schwannomas are benign tumors originating from peripheral, spinal, and cranial nerves and can manifest in any part of the body. However, primary tracheobronchial schwannomas are exceedingly rare, accounting for only 0.2% of bronchial tumors. Surgical intervention remains the preferred treatment modality for bronchial schwannoma (1). In recent years, there have been reports effective removal of schwannomas through bronchoscopy (2); however, long-term efficacy remains inconclusive. Currently, there is a paucity of postoperative follow-up studies on bronchial schwannoma with most being limited to case reports. Consequently, our understanding of postoperative complications associated with this condition is inadequate and no treatment guidelines for managing postoperative airway stenosis of pediatric patients.

The report of diagnostic flexible bronchoscopy in children dates back to 1978 (3). Bronchoscopic interventional therapy plays a pivotal role in the management of respiratory diseases in pediatric patients. Endoscopic balloon dilation, tumor resection, laser therapy, and cryotherapy have gained increasing prominence within the field of pediatrics (4). The utilization of flexible bronchoscopy is also frequently employed for diagnosing and treating abnormal airways (5,6). The current application of flexible bronchoscopy primarily focuses on the diagnosis of asthma, chronic cough, recurrent lower respiratory tract infection, structural abnormalities, and hemoptysis in pediatric patients (7).

In this case, we describe that postoperative central airway stenosis induced by bronchial schwannoma resection was successfully treated by flexible bronchoscope interventional therapy. We present this article in accordance with the CARE reporting checklist (available at https://tp.amegroups.com/article/view/10.21037/tp-2025-286/rc).

Case presentation

An 11-year-old boy was admitted to Boai Hospital of Zhongshan on October 14, 2019, presenting with an 8-day history of cough and wheezing that had worsened over the past day. He had previously been hospitalized at the same hospital from July 27 to August 12, 2019, for schwannoma, bronchopneumonia, and Mycoplasma pneumoniae infection. On August 16, 2019, he was transferred to another hospital for surgical intervention involving carina resection and reconstruction. He recovered well postoperatively and was discharged on September 17, 2019. Eight days before admission to our hospital, the child developed an unprovoked cough and wheezing, leading to admission at another hospital diagnosed by bronchopneumonia and Mycoplasma pneumoniae infection. Chest computed tomography (CT) examination in another hospital revealed pulmonary inflammation; however, symptoms did not alleviate following symptomatic treatment. One day before admission to our hospital, the child’s cough and asthma worsened significantly after physical activity. Additionally, he experienced poor appetite, accompanied by dizziness, fatigue, and profuse sweating. He was then admitted to the Department of Pediatric Respiratory, Boai Hospital of Zhongshan. The child’s guardian denied the genetic history and family history, and previous history of cancer.

After admission, the chest CT examination revealed scattered patchy areas of increased density in both lungs with indistinct boundaries. Mild bronchiectasis was observed in the inferior lingual segment of the left upper lobe and right lower lobe, along with consolidation in the inferior lingual segment of the left upper lobe. Additionally, small protrusions were found in the lower segment of the trachea and at the opening of the left main bronchus, while high-density strip shadows were present on the right side (Figure 1). Flexible bronchoscopy identified more sutures and granulation in the middle and lower segments of the trachea, and tracheobronchial endocarditis (day 3) (Figure 2). Intravenous infusion of ceftriaxone sodium was administered along with atomization for asthma treatment for 3 days. Three sputum cultures exhibited Pseudomonas aeruginosa (multidrug resistant) with a colony count exceeding 4+ cfu/mL, whereas bronchoalveolar lavage fluid culture showed Pseudomonas aeruginosa with a colony count surpassing 3+ cfu/mL. The patient received ceftazidime therapy for 11 days and azithromycin treatment for 3 days. Following a hospital stay lasting 16 days, his cough and wheezing significantly relieved leading to his discharge.

Figure 1 Results of high-resolution spiral plain chest scan. (A) Patchy increased density shadows in both lungs. (B) A high-density strip shadow was seen next to the right side of the left main bronchial opening. (C) The mild bronchiectasis in the lower lobe of the left lung. (D) A small mural protuberant at the opening of the left main bronchus in the lower segment of the trachea.

Figure 2 Findings on a flexible bronchoscope. (A) A large number of surgical residual sutures in the lower segment of the trachea and at the opening of the right main bronchus were observed under the microscope. (B) Microscopically, sputum blocked the middle and lower segments of the trachea. The opening of the right main bronchus was shown in the image.

One day after the first discharge, the child was re-admitted to our hospital’s pediatric intensive care unit due to worsening cough and wheezing for half a day. Amikacin and other symptomatic treatments were administered for one week from day 3; however, there was no relief in symptoms. The child experienced dyspnea and inability to lie flat. Flexible bronchoscopy was performed on day 8, and revealed an increased presence of sutures and granulation tissue at the opening of the right main bronchus, resulting in narrowing. The flexible bronchoscopy with a diameter of 2.8 mm encountered difficulty passing through this area, as well as encountering more sutures and granulation tissue in the middle and lower segments of the trachea. Flexible bronchoscopy examination was performed to cut off suture threads, broken threads were removed using foreign body forceps while granulation tissue was eliminated by holmium laser treatment, laser cutting preceded balloon dilatation at the right main bronchial opening for the first time on day 9 (Figure 3). Interventional bronchoscopy was performed under general anesthesia using propofol, midazolam, sufentanil. Over a period of 1 year following treatment initiation, there were twelve hospitalizations for this child with a total count of twenty-two flexible bronchoscopy interventional treatment conducted including seven holmium laser usages, one electrotomy procedure, seven clamping procedures, nine balloon dilatations procedures, and six cryotherapy sessions. Following treatment completion, the child no longer experienced dyspnea, and subsequent flexible bronchoscopy examination indicated that anteroposterior diameter at right main bronchial opening measured approximately 3.5 mm while left-right diameter measured around 4.5 mm (Figure 4). The patient’s stenotic bronchi had been successfully dilated, and the symptoms of dyspnea had been effectively alleviated. The timeline of the treatment was listed in Table 1.

Figure 3 Interventional bronchoscopy in children. (A) Holmium laser was used to ablate the threads and granulation tissue in the lower part of the trachea. (B) The foreign body forceps secured the outlet head along with a portion of the granulation tissue. The view after removal of granulation tissue by bronchoscopy. (C) Bronchoscopic balloon dilatation was performed in the opening of the right main bronchus.

Figure 4 The changes of main bronchus under bronchoscopy were reexamined after treatment. (A) The mucosa of the lower part of the trachea was smooth without threads or granulation tissue. (B) The carina showed normal airway structure with the right main bronchial opening visible. (C) The mucous membrane of the bronchial opening in the right middle and lower lobe was smooth.

All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s). This study was approved by the Ethics Committee of Boai Hospital of Zhongshan (No. KY-2017-11-41) and was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the legal guardian of the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Discussion

The present case report demonstrated the successful management of central airway stenosis caused by bronchial schwannoma through a combination of holmium laser, electrotomy, cryotherapy, and other techniques performed under flexible bronchoscopy. The favorable outcome achieved in this pediatric patient highlights the safety and efficacy of flexible bronchoscopy interventional therapy for treating airway stenosis associated with bronchial schwannoma.

Tracheal intubation, tracheotomy, surgical-induced granulation hyperplasia, scar contracture stenosis, with or without cartilage ring destruction are the primary etiologies of post-traumatic tracheobronchial stenosis. Due to the significantly narrower lumen in children compared to adults, it is recommended to employ holmium laser ablation for expanding the narrow tracheobronchus after trauma in pediatric patients. Additionally, repeated cryoablation should be performed to manage the wound and base. The long-term effectiveness of balloon dilation alone has not been widely acknowledged (8). Lee and Lawlor concur that combining argon plasma coagulation with cryotherapy can effectively eliminate granulation tissue and alleviate airway obstruction (9,10). Hosna et al. propose bronchoscopic cryotherapy as a simpler alternative to laser surgery and tracheobronchial stent placement for treating post-traumatic tracheal stenosis due to its low risk profile and cost-effectiveness (11). In this case, the airway stenosis was characterized by a cicatricial contracture caused by schwannoma resection. Based on the evidence presented in the references, we speculated that this case could be effectively managed through cryoablation, laser therapy, and other similar treatments.

With the advancement of technology, flexible bronchoscopy has emerged as a valuable tool in the diagnosis and treatment of respiratory disorders in neonates, with minimal occurrence of severe complications (12,13). Li et al. demonstrated the efficacy of interventional treatment using flexible bronchoscopy in 8 pediatric patients with tracheobronchial obstruction and stenosis caused by granulation tissue proliferation due to bronchial foreign bodies. The findings confirmed that flexible bronchoscopy is a safe, reliable, and effective method for managing airway stenosis in children, thus highlighting its potential for clinical application (14). Yang et al. retrospectively observed 16 patients with airway stenosis caused by tracheal mucosal tissue hyperplasia following tracheal intubation, who underwent continuous cryoablation using holmium laser ablation under bronchoscopy. After the initial continuous cryoablation, 75.0% of the hyperplastic tissues achieved complete ablation, while partial removal (>50%) was observed in 25.0% of cases. Subsequent cryoablations resulted in complete ablation of proliferative tissue in 18.75% and 6.25% of patients after the second and third procedures, respectively. Only one patient (6.25%) experienced minor postoperative bleeding at the wound site, but no other surgical complications were reported. No instances of airway stenosis were detected in any patients at both one month and six months following the final cryoablation procedure. These findings suggest that holmium laser cryoablation performed under bronchoscopy is a safe and effective treatment for airway stenosis resulting from tissue proliferation subsequent to tracheal intubation (15). The utilization of balloon dilatation through flexible bronchoscopy may present as an efficacious and secure approach for the early diagnosis and treatment of airway stenosis induced by pulmonary tuberculosis in pediatric patients (16). Interventional techniques, including holmium laser therapy, cryoablation, and balloon dilation performed under flexible bronchoscopy, have been demonstrated to be both effective and safe for treating airway stenosis in pediatric patients. Consequently, we adopted a similar therapeutic strategy in the management of this case. In the course of diagnosis and treatment, the scar tissue was excised and released using a needle electrosurgical knife or laser; dilation of the stenotic airway was performed with a balloon or rigid bronchoscope, and the surface of the stenotic airway was cryoablated.

The application scope of flexible bronchoscopic cryotherapy in pediatrics is comparable to that in adults, primarily for the management of airway obstructive diseases. However, pediatric airway obstruction mainly stems from benign conditions and rarely involves malignant tumors. Therefore, unlike interventional therapy in adults, its objective is to achieve long-lasting relief from symptoms in pediatrics (17). Consequently, careful consideration should be given to interventional therapy, prevention measures, treatment approaches, and long-term complication prognosis when applying this technique in pediatric patients. To effectively eliminate the diseased tissues while minimizing the risk of tracheal perforation and preserving cartilage, collagen, and adipose tissue, cryotherapy was employed in this case.

Endobronchial schwannoma is a rare disease. It has been reported that schwannoma is associated with main bronchial stenosis (18), however, there are no reports of airway stenosis following resection of endobronchial schwannoma. Currently, there is no standardized guideline for managing these complications. To minimize surgical trauma and potential complications, we can draw insights from the experience of utilizing flexible bronchoscopy in treating pediatric patients with central airway obstruction to guide our approach in this particular case.

In conclusion, the issue of airway stenosis necessitates the attention of respiratory physicians. Research has demonstrated that endovascular treatment should be considered as the primary choice for managing simple stenotic lesions (19). However, complex stenotic lesions demand a multidisciplinary approach and often require a surgical intervention. Moreover, it should also be regarded as an effective treatment alternative in selected cases of complex tracheal stenosis.

Conclusions

The flexible bronchoscopy interventional therapy is a safe and effective approach for managing postoperative airway stenosis caused by schwannoma, and is worthy of popularization and application.

Acknowledgments

None.

Footnote

Reporting Checklist: The authors have completed the CARE reporting checklist. Available at https://tp.amegroups.com/article/view/10.21037/tp-2025-286/rc

Peer Review File: Available at https://tp.amegroups.com/article/view/10.21037/tp-2025-286/prf

Funding: This study was supported by the Zhongshan Science and Technology Program Youth Major Project (No. 2017B1012).

Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://tp.amegroups.com/article/view/10.21037/tp-2025-286/coif). The authors have no conflicts of interest to declare.

Ethical Statement: The authors are accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved. All procedures performed in this study were in accordance with the ethical standards of the institutional and/or national research committee(s). This study was approved by the Ethics Committee of Boai Hospital of Zhongshan (No. KY-2017-11-41) and was conducted in accordance with the Declaration of Helsinki and its subsequent amendments. Written informed consent was obtained from the legal guardian of the patient for publication of this case report and accompanying images. A copy of the written consent is available for review by the editorial office of this journal.

Open Access Statement: This is an Open Access article distributed in accordance with the Creative Commons Attribution-NonCommercial-NoDerivs 4.0 International License (CC BY-NC-ND 4.0), which permits the non-commercial replication and distribution of the article with the strict proviso that no changes or edits are made and the original work is properly cited (including links to both the formal publication through the relevant DOI and the license). See: https://creativecommons.org/licenses/by-nc-nd/4.0/.

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