Marked Respiratory Improvement After ECMO‐Supported Exchange From Metallic to Silicone Stent in Tracheobronchial Stenosis due to Tuberculosis: A Case Report

ABSTRACT

A woman in her mid‐50s with tracheobronchial stenosis due to tuberculosis underwent covered metallic stent insertion via flexible bronchoscopy at a referral hospital. Subsequently, an additional silicone Y stent was inserted via rigid bronchoscopy to relieve stenosis distal to the metallic stent. Although her respiratory condition improved markedly after stenting, long‐term complications related to metallic stents such as stent fracture and restenosis were anticipated. Seven months after the first metallic stent insertion, both stents were removed and replaced with silicone stents in accordance with guidelines for the management of benign tracheobronchial stenosis, under veno‐venous extracorporeal membrane oxygenation (ECMO) support without systemic anticoagulation. The procedure was completed successfully without intraoperative complications. Following the insertion of two silicone stents, her respiratory symptoms and pulmonary function improved as the silicone stents seemed to have provided her airway with more stable support. We report a case of successful metallic‐to‐silicone stent replacement under ECMO support in a patient with severe benign airway stenosis.

This report highlighted the importance of silicone stents in the management of benign airway stenosis.

1. Introduction

Long‐term placement of metallic stents in benign airway stenosis (such as tracheobronchial stenosis due to tuberculosis, TSTB) can lead to complications, such as metal fatigue resulting in stent fracture, stenosis from granulation tissue formation and complicated removal. Therefore, silicone stents are generally recommended for long‐term management [1, 2]. We previously described a case using clinical images [1] in which respiratory condition improved after airway stents insertion. However, during follow‐up, granulation tissue formation at the proximal end of the metallic stent and stent fracture developed, necessitating replacement with a silicone stent. This report highlights the importance of silicone stents in the management of benign airway stenosis.

2. Case Report

A woman in her mid‐50s was diagnosed and treated for pulmonary tuberculosis in late 2024. She developed TSTB requiring endotracheal intubation, mechanical ventilation and veno‐venous extracorporeal membrane oxygenation (VV‐ECMO) in the second quarter of 2025. During her hospital stay, a partially covered self‐expandable metallic stent (SEMS; Ultraflex, 14 mm by 60 mm, Boston Scientific, Marlborough, USA), with 7.5 mm uncovered proximal and distal ends, was inserted for trachea stenosis. With initial respiratory stabilisation, she was transferred to our institution for further airway management 2 months after first stent placement. As previously reported [1], a silicone Y stent (Dumon Y 14–10‐10, Novatech, La Ciotat, France), trimmed to trachea length 40 mm, right bronchial length 10 mm and left bronchial length 35 mm, was placed distal to the SEMS. Her respiratory status improved markedly after silicone Y stent insertion.

However, recurrent subglottic stenosis required monthly bronchoscopic interventions including balloon dilatation, cryotherapy and argon plasma coagulation (APC). Granulation tissue growing through the uncovered proximal ends of SEMS was also contributory to airway stenosis (Figure 1). Stent fracture caused by repeated interventions 5 months after placement raised concerns about future airway stenosis. In late 2025, we decided to remove the SEMS and silicone Y‐stent and replace them with two new silicone stents under ECMO support.

FIGURE 1.

Computed tomography and bronchoscopy findings before stent exchange. (A, B) Below the vocal cord, the granulation tissue formed a stenosis on the oral side of the metallic stent. Stent wire fracture was observed on the proximal side of the metallic stent. (C, D) Mid‐lower trachea. Junction between the metallic and silicone stents. (E) The carina of the silicone Y‐stent. (F) The distal side of left main bronchus.

Under general anaesthesia, the patient was intubated with a 6.0 mm endotracheal tube. Cannulation was performed via the femoral vessels (19 Fr and 23 Fr venous cannulas were placed in the left and right femoral veins, respectively, and a 4 Fr arterial sheath was placed in the right femoral artery for emergency access). After priming the circuit with heparinised saline, heparin‐free VV‐ECMO was initiated. After oxygenation was stabilised under ECMO support, the subglottic stenosis was dilated using a pulmonary balloon dilator (10–11‐12 mm CRE Pulmonary Balloon Dilator; Boston Scientific, Marlborough, USA). A rigid bronchoscope (Dumon EFER, Outer Diameter: OD; 12 mm, La Ciotat, France) was then introduced. Granulation tissue on the proximal side of the SEMS was ablated using APC (FiAPC, ERBE, Tübingen, Germany). The summarised image is shown in Figure 2. After careful dissection of the tracheal mucosa using rigid grasping forceps, the SEMS was successfully removed (Figure 2). Collapse of the distal trachea and proximal left main bronchus was observed after removal of the silicone stent. After further balloon dilatation and additional removal of granulation tissue via cryoextraction, sufficient airway patency was achieved. The silicone Y stent (Dumon Y 14–10‐10, Novatech, La Ciotat, France) was trimmed to trachea length of 55 mm, right and left bronchial limb of 10 and 30 mm, respectively. The silicone Y stent was inserted into the left main bronchus and deployed into optimal position by pulling Y‐stent proximally by use of forcep grasper. This technique is often referred to as the pull‐back technique. Subsequently, an additional straight silicone stent (Dumon, OD 14 mm, Novatech, La Ciotat, France) trimmed to 29 mm length was placed proximal to the Y‐stent by using the push‐out technique. The stents were successfully inserted without intra‐operative complications. ECMO was subsequently weaned off and discontinued in the operating room. The procedure time was 180 min. On the following day, the patient was extubated and discharged. However, the patient developed deep vein thrombosis in the femoral veins as a complication of cannulation. Anticoagulation therapy was initiated, and the thrombosis resolved after 1 month.

FIGURE 2.

The image of airway intervention. (A, B) The metallic stent was retrieved through the rigid bronchoscope. (C) The silicone Y‐stent was retrieved through the rigid bronchoscope. (D) After removal of the metallic and silicone stents. (E) Fluoroscopic image showing the metallic stent being retrieved into the rigid bronchoscope. (F) The stents removed under ECMO support.

Four months later, the stenosis had improved sufficiently without the need for additional intervention (Figure 3). Respiratory function markedly improved (Figure 4).

FIGURE 3.

Computed tomography and bronchoscopy findings show the improvement of airway patency after the procedure (4 months after stent exchange). (A, B) Below the vocal cord. (C, D) Upper trachea. (E) Distal to the carina. (F) The distal end of left limb.

FIGURE 4.

The respiratory function test revealed the improvement of the patient's peak flow after stent exchange. (A) Before the procedure. (B) 5 days after the procedure. (C) 4 months after the procedure.

3. Discussion

Interventional bronchoscopic treatment, including stent placement, balloon dilatation and cryotherapy, is an effective therapeutic option for TSTB [3]. SEMS offers the advantage of ease of insertion and may conform more readily to airway anatomy than silicone stents [4]. However, the FDA advised against using SEMS for benign tracheal stenosis due to high risks of severe complications earlier in 2005 [5]. In partially covered SEMS stents, stenosis can occur with granulation growth through uncovered proximal or distal ends. Current guidelines recommend silicone stents for benign central airway stenosis for long‐term management [2].

In the present case, subglottic stenosis due to TSTB and the granulation tissue formation through the uncovered proximal ends of SEMS caused severe airway stenosis. To maintain airway patency, repeated bronchoscopic interventions were required every month, resulting in SEMS fracture within 5 months. Considering that stent fracture may increase the difficulty of stent removal over time, as well as the need for frequent bronchoscopic interventions, we decided to replace the SEMS with two silicone stents, which are generally preferred over metallic stents for benign airway stenosis.

Kim et al. [6] recommended ECMO standby before airway intervention in patients with severe tracheal stenosis, particularly when the minimal airway diameter is ≤ 5 mm. Huan et al. [7] reported a higher risk of airway injury during silicone stent placement in patients with bronchomalacia secondary to endobronchial tuberculosis. Therefore, ECMO support is considered necessary to safely remove and replace stents. In airway bronchoscopic intervention, systemic anticoagulation is associated with bleeding complications; conversely, ECMO without anticoagulation carries a risk of thrombosis. Regarding anticoagulation during VV‐ECMO, previous reports suggest that short‐term ECMO support without systemic anticoagulation may be feasible, with a relatively low risk of thrombosis [8]. Given the substantial bleeding risk associated with SEMS removal, VV‐ECMO was performed without anticoagulation in the present case. Intraoperative bleeding complications did not occur; however, deep vein thrombosis developed 2 weeks after the replacement. As highlighted in the present case, clinicians should be aware of potential complications such as thrombosis and should monitor patients with D‐dimer levels in blood test and venous doppler ultrasound.

The follow‐up interval depends on the patients' condition, degree of stenosis and stent‐related complications. In the present case, bronchoscopic follow‐up was performed monthly. Granulation tissue at the distal end of the left main bronchus was removed and balloon dilation was performed every 2 months after stent replacement. We plan to gradually extend the follow‐up interval to 3 months. Kim et al. [9] reported clinical factors associated with successful removal of airway silicone stents in patients with TSTB. Although current guidelines [2] recommend attempting stent removal 6–12 months after placement, stent removal was not considered appropriate in this patient because of multiple risk factors for re‐stenosis after silicone stent removal.

In conclusion, the placement of a SEMS worsened granulation tissue formation and stenosis during follow‐up. However, replacement with a silicone stent suppressed the progression of stenosis at the stent edge, resulting in a marked improvement in respiratory function.

Author Contributions

Mayu Goda and Yuki Takigawa prepared the manuscript, which was reviewed by all co‐authors.

Funding

The authors have nothing to report.

Consent

The authors declare that written informed consent was obtained for the publication of this manuscript and the accompanying images using the consent form provided by the journal.

Conflicts of Interest

The authors declare no conflicts of interest.

Goda M., Takigawa Y., Sato K., et al., “Marked Respiratory Improvement After ECMO‐Supported Exchange From Metallic to Silicone Stent in Tracheobronchial Stenosis due to Tuberculosis: A Case Report,” Respirology Case Reports 14, no. 6 (2026): e70639, 10.1002/rcr2.70639.

Data Availability Statement

The data that support the findings of this study are available from the corresponding author upon reasonable request.