Silicone stents, the rigid bronchoscope, and the standard of care in central airway stenosis

Biodegradable tracheal stents: our ten-year experience with adult patients

BACKGROUND

Biodegradable (BD) stents made from polydioxanone have been used only in human airways. These stents combine the advantages of classical tracheal stents, and fewer side effects are expected due to their biocompatibility and their time-limited presence in airways. However, new clinical consequences have arisen. Here, the authors share their experiences with BD stents for tracheal indications, focusing on their safety and efficacy.

METHODS

This was a retrospective review of a collected database of adult patients who underwent implantation of biodegradable tracheal stents between September 2013 and December 2022 at the Department of Respiratory Medicine of the 1st Faculty of Medicine in Prague and Thomayer University Hospital. The indications included functionally significant nonmalignant tracheal stenosis and tracheomalacia. Self-expandable, biodegradable, polydioxanone tracheal stents manufactured by ELLA-CS Ltd. (Hradec Kralove, Czech Republic) were implanted during rigid bronchoscopy under general anaesthesia. All patients were followed up in the department and were provided with the necessary care. The main efficacy and safety parameters and relationships were analysed using descriptive statistics and Fisher´s exact, Wilcoxon and Kruskal‒Wallis tests.

RESULTS

A total of 65 stents were implanted in 47 adult patients. During the first two months after implantation, when adequate function was expected, the stent was found to be effective in 26 out of 39 patients who completed this period (66.7%). The clinical effectiveness reached 89.7%, as early restenoses were mostly mild and necessitated treatment in only 4 patients. The frequencies of significant mucostasis, migration and granulation tissue growth were 2.6%, 7.5% and 23.1%, respectively, during this period. Thirty-four participants completed the half-year follow-up period after the first or second stent insertion, and some were followed up beyond this period. Poor control of symptoms, the development of restenosis and the need for interventions were characteristic of this period as the stents degraded. Twenty-two patients who experienced remodelling or stabilization of the tracheal lumen achieved a stent-free state. Seven patients underwent subsequent surgical treatment.

CONCLUSIONS

BD stents are safe and provide adequate tracheal support until they begin to degrade. The use of BD stents necessitates close monitoring of patients and accurate treatment of possible restenosis.

TRIAL REGISTRATION

Based on project NT14146 - Biodegradable stents in the management of the large airways (2013-2015, MZ0/NT), registered on May 1, 2013, in the Research and Development and Innovation Information System of the Czech Republic and at ClinicalTrials.gov (reg. no. NCT02620319, December 2, 2015).

Adolescent and Young Adult Patients with Vaginal Graft-vs-Host Disease and Hematocolpos Managed with Vaginal Stents: A Case Series

STUDY OBJECTIVE

Vaginal stenosis can be acquired as a result of vaginal graft-vs-host disease (GVHD) in patients who have undergone hematopoietic stem cell transplant (HSCT). Little data exist to guide the management of vaginal GVHD, particularly in adolescent and young adult patients. The objective of this study was to detail the management of vaginal stenosis with lysis of adhesions and vaginal stent placement in 3 young patients with vaginal GVHD.

METHODS

A retrospective chart review was done for 3 patients with vaginal GVHD causing vaginal stenosis with hematometrocolpos. All 3 were treated using vaginal stent placement. Additionally, a literature review was conducted through PubMed and Google Scholar to identify 21 case reports (with a total of 35 patients) of menstrual obstruction due to GVHD.

RESULTS

Obstructive vaginal stenosis secondary to vaginal GVHD occurred in our patients at ages 15, 16, and 24 years. Resolution of hematocolpos was obtained with lysis of vaginal adhesions with vaginal stent placement in all patients, with varying regimens of systemic and topical hormones, topical corticosteroids, and dilator therapy.

DISCUSSION

Vaginal stenosis secondary to vaginal GVHD should be considered in patients with a history of allogeneic HSCT presenting with amenorrhea, especially those with a diagnosis of primary ovarian insufficiency. The use of vaginal stents, along with postoperative medical and dilator management as appropriate, may prevent re-stenosis, although more information is needed regarding the efficacy of treatments.

Tracheobronchial stents: an expanding prospect

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean-Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel-titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug-eluting and three-dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction.

Management of post-traumatic tracheal stenosis with silicone stent placement

Benign airway stenosis often poses a therapeutic challenge and requires a multidisciplinary approach involving interventional pulmonologists and thoracic surgeons. We report the case of a man who presented with thoracic trauma following a road traffic accident. His chest X-ray showed complete collapse of the right lung, while screening flexible bronchoscopy revealed pooled secretions and asymmetric mid-to-lower tracheal stenosis. After thorough clinicoradiological evaluation and multidisciplinary discussion, we proceeded with therapeutic rigid bronchoscopy and silicone stenting of the tracheal stenotic lesion. Post-procedure, the patient improved clinically and also showed radiological improvement. Subsequently, he underwent stent removal and remains in follow-up. While surgery is a definitive modality for management of benign tracheal stenosis, most patients with advanced disease, pneumonia or with poor general condition are unfit to tolerate general anaesthesia or surgery. In such patients, minimally invasive bronchoscopic techniques that are generally safe to perform have led to substantial improvement in symptoms and long-term quality of life.

Bronchoscopy Laser and Silicone Y-Stents as Emergency Airway Management in Central Airway Stenosis Due to Secondary Thyroid Carcinoma: A Case Report

Total airway obstruction in thyroid cancer is rare and has high morbidity and mortality. Airway management in such cases is challenging, especially in cases in which thyroid masses cannot be totally resected. It is important to choose the appropriate airway treatment modality. Currently, therapeutic rigid bronchoscopy procedures and endoluminal lasers, as well as airway stent insertion, are a management modality of near-total malignant airway obstruction. We report a rigid bronchoscopy procedure combined with laser and Y-stent silicone insertion in thyroid cancer with extension infiltration, as well as compression in the trachea covering the subglottic tracheal area up to the main carina and tracheo-bronchomalacia, manifesting as acute respiratory failure.

External fixation of airway stents for upper tracheal stenosis and tracheoesophageal fistula

OBJECTIVES

Stent migration is a common complication of airway stent placement for upper tracheal stenosis and tracheoesophageal fistula. Although several researchers have reported that external fixation is effective in preventing stent migration, the usefulness and safety of external fixation have not been proved because their cohorts were small. We therefore investigated the efficacy and safety of external fixation during upper tracheal stenting.

METHODS

Records of patients who underwent airway stent placement from May 2007 to August 2018 in a single centre were retrospectively reviewed. We included only patients whose stent had been placed in the upper trachea with external fixation to the tracheal wall. The primary endpoint of this study was the rate of stent migration.

RESULTS

Altogether, 51 procedures were performed in 45 patients (32 males, 13 females; median age 60 years, range 14-91 years). The median follow-up period was 9 months (range 0.3-90 months). Among the procedures, 15 were performed for benign disease and 36 for malignancy. Stents were composed of either silicone (n = 42) or metal (n = 9). Stent migration occurred in 3 (6%) patients. The stents with migration were all composed of silicone. Other sequelae were granulation tissue formation in 10 (20%) patients, sputum obstruction in 6 (12%), cellulitis in 3 (6%) and pneumonia in 1 (2%).

CONCLUSIONS

External fixation was an effective method for preventing migration of airway stents placed for upper tracheal stenosis and tracheoesophageal fistula. The complications were acceptable in terms of safety.

Three-dimensional printed degradable splint in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis

Pulmonary artery sling is a congenital cardiovascular disease and is usually accompanied by tracheobronchial stenosis. Generally, infants diagnosed with pulmonary artery sling should have surgery. However, the treatment of tracheobronchial stenosis is still controversial. Our team developed a customised, degradable, three-dimensional printed splint and successfully applied it in the treatment of pulmonary artery sling associated with severe bilateral bronchus stenosis. We suggested that three-dimensional printing may be a novel and effective way to treat tracheobronchial stenosis and other diseases in children.

[Management of a tracheal adenoid cystic medico-surgical carcinoma]

Adenoid cystic carcinoma or cylindroma is a rare tumor of the trachea which arises from mucous secreting cells. Its evolution and growth are slow but it is often fatal in the absence of radical treatment. The latter relies on a surgical sleeve resection of the pathological area, with a tracheo-tracheal anastomosis. Therapeutic bronchoscopy plays a crucial role in the clinical improvement of patients before surgery which will be performed under better conditions. For inoperable patients, radiotherapy has proved its efficacy, unlike conventional chemotherapy. The finding of biomarkers expressed by tumor cells could lead to target therapies. This case report illustrates the efficient combination of therapeutic bronchoscopy and surgery for the treatment of adenoid cystic carcinoma affecting central airways.

Biodegradable polydioxanone stents in the treatment of adult patients with tracheal narrowing

Background

Biodegradable stents that disintegrate after a period of time are expected to be well tolerated and have advantages over other stents that are more commonly used in practice today. Polydioxanone is a biodegradable polymer that is widely used during surgery with absorbable sutures.

Methods

We present cases from the first four patients to undergo a tracheal polydioxanone stent insertion. Indications included significant non-malignant tracheal stenosis in cases where primary surgical treatment was not possible. The stents were implanted using rigid bronchoscopy and patients received regular follow-ups as needed. This use of biodegradable stents in adult patients was a novel, previously untested approach. The study was approved by the Institutional Ethics Committee and was based on a project entitled; “Biodegradable stents in the management of stenoses of large airways” (project NT 14146-3/2013).

Results

Six biodegradable stents were implanted in four patients with benign stenoses. No technical difficulties occurred and no serious or life-threatening events were recorded. All patients reported some benefit from treatment.

Conclusion

Polydioxanone tracheal stents can be considered when a need for temporary support is expected, and as an alternative to other stents if the latter could compromise the patient. Owing to limited experience and observed disadvantages, further research is needed to fully assess this treatment.

Trial registration

This work is based on project NT14146 - Biodegradable stents in the management of stenoses of the large airways (2013–2015, MZ0/NT), registered from May 1, 2013 in The Research and Development and Innovation Information System of the Czech Republic and in ClinicalTrials.gov, reg. no. NCT02620319, December 2, 2015.