Airway Stenting Revisited: 30 Years, the Age of Reason?

World Association for Bronchology and Interventional Pulmonology (WABIP) guidelines on airway stenting for malignant central airway obstruction

Malignant Central Airway Obstruction (MCAO) encompasses significant and symptomatic narrowing of the central airways that can occur due to primary lung cancer or metastatic disease. Therapeutic bronchoscopy is associated with high technical success and symptomatic relief and includes a wide range of airway interventions including airway stents. Published literature suggests that stenting practices vary significantly across the world primarily due to lack of guidance. This document aims to address this knowledge gap by addressing relevant questions related to airway stenting in MCAO. An international group of 17 experts from 17 institutions across 11 countries with experience in using airway stenting for MCAO was convened as part of this guideline statement through the World Association for Bronchology and Interventional Pulmonology (WABIP). We performed a literature and internet search for reports addressing six clinically relevant questions. This guideline statement, consisting of recommendations addressing these six PICO questions, was formulated by a systematic and rigorous process involving the evaluation of published evidence, augmented with expert experience when necessary. Panel members participated in the development of the final recommendations using the modified Delphi technique.

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.

Advancements in airway stents: a comprehensive update

PURPOSE OF REVIEW

This review provides an overview of the evolving field of airway stenting (AS), highlighting its relevance in the management of central airway obstruction (CAO). It discusses recent advancements, including 3D-printed silicone stents (3DPSS), metallic stents, biodegradable stents (BS), and drug-eluting stents (DES), which are transforming clinical practice. The review underscores the ongoing challenges in patient selection, stent choice, and long-term management in the context of an evolving landscape.

RECENT FINDINGS

Innovations, particularly 3DPSS, have shown promise in providing patient-specific solutions. These stents offer improved symptom relief, enhanced quality of life, and lower complication rates, especially for complex airway diseases. The use of BS and DES is explored, raising prospects for future applications.

SUMMARY

The evolution of AS reflects a deepening understanding of airway obstructions. Recent innovations, such as 3DPSS, BS, and DES, show considerable promise in addressing the limitations of conventional stents. However, challenges related to complications, patient selection, and long-term management persist, demanding further research. Wide practice variations in the management of AS highlight the need for more clinical data and standardized guidelines. The search for the ideal stent continues, driven by the pursuit of better outcomes for patients with CAO.

[Tracheobronchial stenting in patients with non-resectable tumors complicated by airway stenosis]

OBJECTIVE

To study the results and efficiency of tracheobronchial stenting in patients with unresectable tumors complicated by stenosis of central airways.

MATERIAL AND METHODS

We analyzed the results of tracheobronchial stenting in 23 patients with unresectable tumors complicated by stenosis of central airways between 2016 and 2021.

RESULTS

Technical and clinical success rate was 100%. No intraoperative complications were noted. Dyspnea regressed in all patients in early postoperative period. Moreover, there was objective improvement in lung ventilation with increase in lung capacity (from 2.1±0.4 to 2.7±0.5 l; p<0.05), forced expiratory volume (from 1.2±0.5 to 1.8±0.4 l; p<0.05), partial pressure of oxygen in arterial blood (from 47±7.4 to 85±6.3 mm Hg; p<0.05) and arterial oxygen saturation (from 86.1±8.2 to 93.1±5.1%; p<0.05). One patient developed massive bleeding due to tumor decay on the 3^rd day after surgery. In 2 patients, stent obturation with a «mucus plug» was observed after 2-3 postoperative days. In 3 months after surgery, 21.8% of patients had disturbances of external respiration accompanied by mild dyspnea due to granulation tissue growth. Stent migration in 3 months after endoscopic stenting was recorded in 1 patient. Three-month mortality was 26.1%.

CONCLUSION

Tracheobronchial stenting is a safe and effective minimally invasive surgical intervention. As a part of palliative care, this procedure improves functional and clinical parameters of pulmonary ventilation and reduces the incidence of complications. Thus, quality of life in patients with unresectable tumors complicated by airway stenosis is improved.

Tracheobronchial stents in patients with malignant airway disease: Finnish tertiary care experience

OBJECTIVES

Tracheobronchial stenting has an established role in the palliation of malignant central airway obstruction (CAO). The purpose of this study is to describe the experience with self-expanding metal airway stents in 2 tertiary referral centres, covering a third of the population of Finland.

PATIENTS AND METHODS

Patients referred to and treated with airway stenting for malignant CAO using self-expanding metal-stents were identified from electronic patient records, and data were collected using a structured Endoscopic Lower Airway Management instrument. Statistical analysis to reveal factors affecting patient benefit and survival was carried out.

RESULTS

A total of 101 patients (mean age 65.8) and 116 procedures were identified. Procedure-related mortality was rare (3/101 patients) and complications infrequent. The median survival was 2.3 months [95% confidence interval (CI): 1.4-3.1). Stent benefit was not significantly affected by clinical characteristics. Survival was impacted by the use of adjunct procedures [hazard ratio (HR) 0.36, 95% CI: 0.23-0.58, P < 0.001), procedural urgency (HR 0.40; 95% CI: 0.23-0.71, P = 0.002) and post-treatment chemoradiotherapy (HR 0.29, 95% CI: 0.15-0.56, P < 0.001).

CONCLUSIONS

The beneficial impact observed supports the further use of tracheobronchial stenting in malignant CAO. The use of self-expanding metal stents is encouraged.

Tracheobronchial stent sizing and deployment practices airway stenting practices around the world: a survey study

Background

Tracheobronchial stents types, uses, techniques for deployment and extraction have practice variations around the world.

Methods

We collected responses by sending an online survey of 8 questions to world interventional bronchology member societies and social media groups.

Results

There were 269 respondents from 47 countries. Europe had 97 respondents from 22 countries. There were 8 respondents from Australia, 7 from Africa (3 countries) and 7 from 4 countries in South America (SA). North America (NA) had 72 respondents from 3 countries. Asia had 78 respondents from 14 countries. For stent placements 15% [41] used fiberoptic bronchoscope (FB) only. Rigid bronchoscopy (RB) was solely utilized by 38% [102]. Forty-six percent [123] used a combination of RB and FB (P value <0.00001). For stent extraction 13% [19] used FB alone, 57% [85] used RB, and 36% [54] used a combination of RB and FB (P value <0.00001). Placement of stents were 50.5% [135] only by direct visualization. Twenty-three percent [61] always used fluoroscopic guidance. Twenty-six-point-five percent [71] used fluoroscopy in certain cases (P value <0.00001). Sixty percent [162] decided stent sizing by measurements of stenotic and non-stenotic areas on radiology. Twelve percent [32] respondents used sizing devices. Sixty-five percent [177] used a ruler and bronchoscope to measure stenotic areas. Thirty-eight percent [104] used visual estimation and experience. Seven percent [19] used serial balloon dilatation size. To prevent clogging of stents, 22% [59] prescribed mucolytics. Seventy-three percent [195] nebulized saline, 26% [70] had Mucomyst Nebulization, 24% [65] Nebulized bronchodilators and other methods 11% [30] were advised. Covered self-expandable metal stents (SEMS) 44% was the commonest type of stent used around the world. Silicone stents 37%, Y stents 15%, uncovered SEMS 12%, Montgomery T tube 5% followed. Polyflex stents 3% and custom-made stents 3% were least used. Biodegradable stents were used by 7.5%, and not used by 92.5%.

Conclusions

Tracheobronchial stent practice norms have slowly evolved, but its practice variations lack uniformity, and have sparse evidence-based studies for its direction.

Indications and clinical outcomes of fully covered self-expandable metallic tracheobronchial stents in patients with malignant airway diseases

BACKGROUND

Airway stenting is an efficacious approach in management of malignant airway disease (MAD) with improvement in survival outcome.

OBJECTIVE

To determine the indications and long-term clinical outcomes of tracheobronchial stenting in patients with MAD.

METHODS

A cross-sectional review of 51 patients who underwent airway stenting from June 2011 to June 2019 was done. Paired t-test was used to compare mean difference of clinical characteristics between pre- and post-airway stenting. Kaplan-Meier curves were used to assess overall survival.

RESULTS

A total of 51 patients had stent insertion with mean age 46.63±17.10years including 27(52.9%) females. Mainly 37(72.5%) patients had esophageal and 06(11.8%) had lung cancer. The main indications were bronchial stenosis 18(35.3%), tracheal stenosis 11(21.6%) and Tracheo-esophageal/bronchial fistula 13(25.5%). Obstruction was intrinsic, extrinsic and mixed in 20(39.2%), 13(25.5%) and 5(9.8%) patients, respectively. There was statistically significant mean difference in pre- and post-procedure oxygen saturation (mean (M)=89.8, standard deviation (SD)=6.70 vs M =95.5,SD=2.54.p =0.001) and performance status (M =3.65,SD =0.6 vs M =2.59, SD=0.83.p =0.001). Overall median survival was 16±3.44 weeks, highest amongst patients with intrinsic obstruction (27±6.51 weeks).

CONCLUSION

Airway stenting is an effective endoscopic procedure to re-establish airway patency in MAD with minimal complications..

[Current Status and Development of Interventional Techniques for Pulmonary Diseases]

Bronchoscope is the core part of the interventional diagnosis and treatment technology for lung diseases, which has experienced more than 100 years of development history. It has gradually formed a diagnosis and treatment model of pulmonary diseases with cooperation of multi-clinical disciplines, deep integration of interventional minimally invasive techniques, and cross-integration of diversified diagnosis and treatment concepts. This article aimed to review the current status and development of interventional diagnosis and treatment techniques for lung diseases, and introduces the characteristics of the interventional treatment of our center.

Airway stent current practices evaluation: Survey among French bronchoscopy practitioners

BACKGROUND

Airway stenting (AS) is performed for the treatment of benign or malignant central airway stenosis. In France, more than 30 centers practice AS. The aim of this survey was to evaluate the current practice around airway stenting among French bronchoscopy practitioners.

METHOD

We performed an online survey sent to the GELF group (Groupe d'Endoscopie de Langue Française) mailing list. The first part comprised 10 questions about the different attitudes before AS and the second part included 10 questions about the management after AS.

RESULTS

Thirty-six participants answered to the first part of the questionnaire and thirty-three to the second. There were some similarities, for example the absence of prophylactic antibiotic treatment before procedure (86%), use of saline nebulization, and removing or replacing the airway stent in case of persistent chest congestion or infection (73%). We also noted an important heterogeneity of the practices with several differences concerning systematic endoscopic control, bacteriological sampling before procedure (44%) and systematically AS replacement.

CONCLUSION

This survey shows that AS management in France varies between practitioners. Respondents agreed on a few points, but disagreed on several important aspects of the management. These results emphasize the need of expert recommendations to improve AS management.

Airway stenting: Technological advancements and its role in interventional pulmonology

AS offers rapid and sustained relief of symptoms in most patients treated for malignant or benign CAO and can also be curative in itself in cases of benign tracheobronchial stenosis. In the past 30 years, this field has seen significant progress, from the misuse of vascular non-covered metallic stents to the development of silicone airway stents with an increasingly large panel of shapes and of hybrid, partially or fully covered, SEMS customized to the airways. This study aims to offer an overview on: (i) the respective advantages and drawbacks of these two main categories of devices; (ii) the main indications for AS and the rationale behind the choice of stent in each situation; and (iii) the main promises borne from the progress made in the field in the past few years, including the development of drug-eluting, biodegradable or patient-specific customized AS.

Anesthetic considerations for bronchoscopic procedures: a narrative review based on the Cleveland Clinic experience

The advent of advanced diagnostic bronchoscopy has shown an increased demand for anesthesiologists to administer anesthesia in the bronchoscopy suite. Procedures such as navigational bronchoscopy, airway stenting and advanced therapeutic procedures often require the presence of an anesthesiologist to manage these more complex patients and procedures. In this review we describe the various bronchoscopic procedures and anesthetic management and complications of these procedures at our institution The Cleveland Clinic, Cleveland Ohio.

3D printing for airway disease

It has been 30 years since the first commercial three-dimensional (3D) printer was available on market. The technological advancement of 3D printing has far exceeded its implementation in medicine. The application of 3D printing technology has the potential of playing a major role within interventional pulmonology; specifically, in the management of complex airway disease. Tailoring management to the patient-specific anatomical malformation caused by benign or malignant disease is a major challenge faced by interventional pulmonologists. Such cases often require adjunctive therapeutic procedures with thermal therapies followed by dilation and airway stenting to maintain the patency of the airway. Airway-stent size matching is one key to reducing stent-related complications. A major barrier to matching is the expansion of the stent in two dimensions (fixed sizes in length and diameter) within the deformed airway. Additional challenges are created by the subjective oversizing of the stent to reduce the likelihood of migration. Improper sizing adversely affects the stability of the stent. The stent-airway mismatch can be complicated by airway erosion, perforation, or the formation of granulation tissue. Stents can migrate, fracture, obstruct, or become infected. The use of patient-specific 3D printed airway stents may be able to reduce the stent airway mismatch. These stents allow more precise stent-airway sizing and minimizes high-pressure points on distorted airway anatomy. In theory, this should reduce the incidence of the well-known complications of factory manufactured stents. In this article, the authors present the brief history of 3D printed stents, their consideration in select patients, processing steps for development, and future direction.

Recurrent respiratory papillomatosis with lung involvement

Recurrent respiratory papillomatosis (RRP) is a rare disease caused by human papillomavirus. Aggressive forms of RRP require repeated cytoreductive surgery to restore airway patency. Tracheal disease is even less common and lung parenchyma is involved in less than 1% of patients. We present reports of three cases of RRP with progressive lung disease in adult patients.