Tracheal stenosis in prolonged mechanically ventilated patients: prevalence, risk factors, and bronchoscopic management

Background

Various complications may arise from prolonged mechanical ventilation, but the risk of tracheal stenosis occurring late after translaryngeal intubation or tracheostomy is less common. This study aimed to determine the prevalence, type, risk factors, and management of tracheal stenoses in mechanically ventilated tracheotomized patients deemed ready for decannulation following prolonged weaning.

Methods

A retrospective observational study on 357 prolonged mechanically ventilated, tracheotomized patients admitted to a specialized weaning center over seven years. Flexible bronchoscopy was used to discern the type, level, and severity of tracheal stenosis in each case. We described the management of these stenoses and used a binary logistic regression analysis to determine independent risk factors for stenosis development.

Results

On admission, 272 patients (76%) had percutaneous tracheostomies, and 114 patients (32%) presented mild to moderate tracheal stenosis following weaning completion, with a median tracheal cross-section reduction of 40% (IQR 25–50). The majority of stenoses (88%) were located in the upper tracheal region, most commonly resulting from localized granulation tissue formation at the site of the internal stoma (96%). The logistic regression analysis determined that obesity (OR 2.16 [95%CI 1.29–3.63], P < 0.01), presence of a percutaneous tracheostomy (2.02 [1.12–3.66], P = 0.020), and cricothyrotomy status (5.35 [1.96–14.6], P < 0.01) were independently related to stenoses. Interventional bronchoscopy with Nd:YAG photocoagulation was a highly effective first-line treatment, with only three patients (2.6%) ultimately referred to tracheal surgery.

Conclusions

Tracheal stenosis is commonly observed among prolonged ventilated patients with tracheostomies, characterized by localized hypergranulation and mild to moderate airway obstruction, with interventional bronchoscopy providing satisfactory results.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-022-01821-6.

Clinical application of PEAK PlasmaBlade to remove distal tracheal granulation in patients after tracheostomy

OBJECTIVE

Tracheal granulation is one of the common long term complications in patients after tracheostomy. Hypertrophic tracheal granulation may cause airway obstruction and further operation may be required to recreate an airway. Distal tracheal granulation is clinically challenging because of its position and surgical field limitation. This retrospective case review study evaluated the outcomes of PEAK PlasmaBlade-assisted tracheal surgery in patients with distal tracheal granulation.

METHODS

This study retrospectively reviewed patients with distal tracheal granulation following long-term tracheostomy. All patients received PEAK PlasmaBlade assistance tracheal surgery (PATS) between February 2013 and December 2019. The surgery was performed using the PEAK PlasmaBlade with TnA type tip, powered by a PULSAR Generator, and guided by a 45 ° rigid endoscope. Patients were regularly followed up for a minimum of 12 months.

RESULTS

A total 21 patients had completed PATS. None of the patients experience immediate life-threatening complications during or after the procedure. All the 21 patients were free of recurrent obstructive granulation within 12 months after operation.

CONCLUSION

PATS is practical, effective, and safe for distal tracheal granulation and can be performed by single surgeon. Furthermore, it is technically less demanding than other surgical approaches and it has a rapid learning curve.

Factors associated with the occurrence of stomal stenosis after tracheostomy in adults

OBJECTIVE

Although tracheal stomal stenosis can be life-threatening, factors associated with the occurrence of stomal stenosis remain unknown. This study was performed to evaluate these factors in adult patients.

METHODS

We retrospectively identified adult patients who underwent tracheostomy from 2010 to 2016 using a Japanese national inpatient and outpatient database. We performed Cox proportional hazard regression analyses to evaluate factors associated with the occurrence of tracheal stomal stenosis.

RESULTS

We obtained data on 25,436 eligible patients. The proportion of tracheal stomal stenosis was 0.9%. Tracheal stomal stenosis was significantly less likely to occur in patients with regular use of oral steroids [hazard ratio (HR), 0.28; 95% confidence interval (CI), 0.09-0.88; P = 0.03] and in male patients (HR, 0.75; 95% CI, 0.57-0.97; P = 0.03). The occurrence of tracheal stomal stenosis was significantly associated with use of a mechanical ventilator at home (HR, 2.54; 95% CI, 1.55-4.15; P < 0.001) and a body mass index of <18.5 kg/m² (HR, 1.45; 95% CI, 1.06-1.99; P = 0.02).

CONCLUSION

Our study revealed several factors that are associated with tracheal stomal stenosis. These findings may help physicians to manage tracheal stomas.

Microscopic examination of iatrogenic subglottic tracheal stenosis: observations that may elucidate its histopathologic origin

OBJECTIVES

The histopathologic origin of iatrogenic subglottic tracheal stenosis (ISTS) remains unclear. The purpose of this study was to use detailed operative microscopy to systematically examine the operative en bloc specimens of patients with ISTS and to observe the histologic and morphological changes in the hopes that these observations will provide insight into the histopathologic origin of these devastating injuries.

METHODS

The operative specimens of 18 patients who underwent open tracheal or laryngotracheal resection for ISTS were examined. Precise morphological characteristics were investigated for each tissue layer, including the adventitia, the outer surface of the perichondrium, the cartilage, the inner surface of the perichondrium, the submucosa, and the mucosa. Each tissue layer was evaluated independently and in relationship to the other layers. The cartilaginous airway was further evaluated relative to the pars membranacea.

RESULTS

The most common morphological finding in the epithelium was squamous metaplasia with occasional intense inflammation visible in the underlying mucosa, including cicatrization. The underlying cartilage demonstrated ossific metaplasia with sequestration in many cases. By far the most pronounced changes were found in the outer perichondrium and overlying adventitia and included diffuse paucicellular or hyperplastic fibrosis with intense hyperplastic scar formation or hyaline cicatrization. In the pars membranacea, severe scar formation and hyperplastic fibrosis were predominant. Ossific metaplasia was particularly severe in the lateral or outer parts of the tracheal ring, particularly in the vicinity of the adventitia and outer perichondrium. These changes were much more pronounced than the relatively minor changes observed in the submucosa and mucosa.

CONCLUSIONS

The most severe pathologic observations occurred in the lateral tissue layers, ie, the outer perichondrium and adventia. Given that an injury occurs from the tracheal lumen, these tissue layers have the greatest distance from the site of injury. As only minor changes occurred in the inner tissue layers, we hypothesize that these tissues have a greater regenerative capacity than the outer layers. This study supports the theory that the depth of the airway injury is more critical to the development of ISTS than is the extent or length of the injury.