Treatment of cuff-related tracheal stenosis with a fully covered retrievable expandable metallic stent

Management of stent-related tracheoesophageal fistula in complex post-tuberculosis tracheobronchial stenosis: A case report

Background

The covered self-expandable metallic stents (SEMS) have been used to manage benign tracheobronchial stenosis, especially the complex post-tuberculosis (TB) tracheobronchial stenosis (PTTS) with cartilage destruction or malacia. This procedure could lead to stent-related tracheoesophageal fistula (TEF).

Case presentation

A 21-year-old woman, who had one covered Y-shaped SEMS inserted to manage complex PTTS 2 years ago, presented with dyspnea and frequent coughing on drinking water. The bronchoscopy confirmed extensive granulation tissue hyperplasia and a TEF on the upper edge of the covered SEMS. The covered SEMS was removed in three steps, and another fully covered Y-shape SEMS (Microtech Co., Ltd., Nanjing, China) was inserted to restore patency in the tracheobronchial tree and occlude the TEF orifice. Recombinant bovine basic fibroblast growth factor (rbFGF) (6,000 IU/time) was sprayed into and around the fistula through the V-System single-use cannula via the flexible bronchoscope every other week. The patient showed sustained clinical and radiographic improvement, and the TEF healed.

Conclusion

We presented a three-step bronchoscopic approach to managing a stent-related TEF in a patient with complex PTTS. Subsequently, regular bronchoscopic debridement of granulation tissue developing on the upper edge of SEMS is necessary to maintain the stent patency and reduce the risk of recurrent stent-related TEF. A fully covered SEMS associated with the local administration of rbFGF seems to offer an alternative simplified one-stage procedure for the temporary management of TEF combined with complex PTTS in non-surgical candidates.

Novel Therapy for Acquired Tracheomalacia with a Tissue-Engineered Extraluminal Tracheal Splint and Autologous Mesenchymal-Derived Chondrocytes

Introduction Acquired tracheomalacia (ATM) is characterized by a loss of structural strength of the tracheal framework, resulting in airway collapse during breathing. Near half of the patients undergoing prolonged invasive mechanical ventilation will suffer tracheal lesions. Treatment for ATM includes external splinting with rib grafts, prosthetic materials, and tracheal resection. Failure in the use of prosthetic materials has made reconsidering natural origin scaffolds and tissue engineering as a suitable alternative.

Objective To restore adequate airway patency in an ovine model with surgically-induced ATM employing a tissue-engineered extraluminal tracheal splint (TE-ETS).

Methods In the present prospective pilot study, tracheal rings were partially resected to induce airway collapse in 16 Suffolk sheep (Ovis aries). The TE-ETS was developed with autologous mesenchymal-derived chondrocytes and allogenic decellularized tracheal segments and was implanted above debilitated tracheal rings. The animals were followed-up at 8, 12, and 16 weeks and at 1-year postinsertion. Flexible tracheoscopies were performed at each stage. After sacrifice, a histopathological study of the trachea and the splint were performed.

Results The TE-ETS prevented airway collapse for 16 weeks and up to 1-year postinsertion. Tracheoscopies revealed a noncollapsing airway during inspiration. Histopathological analyses showed the organization of mesenchymal-derived chondrocytes in lacunae, the proliferation of blood vessels, and recovery of epithelial tissue subjacent to the splint. Splints without autologous cells did not prevent airway collapse.

Conclusion It is possible to treat acquired tracheomalacia with TE-ETS without further surgical removal since it undergoes physiological degradation. The present study supports the development of tissue-engineered tracheal substitutes for airway disease.

Post-tuberculosis tracheobronchial stenosis: long-term follow-up after self-expandable metallic stents placement and development of a prediction score-the Restenosis Score

Background

The insertion of self-expandable metallic stents (SEMS) for post-tuberculosis tracheobronchial stenosis (PTTS) was controversial. This study aimed to evaluate the efficacy and safety of SEMS for treating PTTS, and developed a scoring system for predicting the occurrence of restenosis after stenting in PTTS patients.

Methods

We conducted a retrospective review of 87 patients who were diagnosed with PTTS and experienced SEMS insertion between January 2000 and December 2017. All procedures were performed via flexible bronchoscopy under conscious sedation and local anesthesia.

Results

A total of 85 SEMS were successfully placed in 77 patients. Comparing with pre-stenting, there were significant improvements in the lumen diameters of the stenotic segment, mMRC scale and lung function after short-term SEMS placement. During the long-term (average 163.32 months) follow-up, 48 patients (62.3%) did not develop restenosis after stenting; the other 29 patients (37.7%) developed and eventually, 12 remained under interventional therapies and 11 had bronchial atresia. Multivariate Cox regression analysis revealed that the difference value between SEMS length and the stenosis-segment length, stenosis type, and the number of pre-stenting thermal ablation were independently related to restenosis occurrence and were subsequently used to establish the Restenosis Score. The model’s development group (0.83, 95% CI 0.74–0.92) and external validation set (0.94, 95% CI 0.77–1.00) showed excellent discrimination.

Conclusion

SEMS placement could serve as a safe and effective treatment option for most patients with PTTS. Further, we built a prediction model depending on the independent predictors of restenosis occurrence, the Restenosis Score. This validated tool might provide a decision support and a better management for PTTS patients who underwent SEMS implantation.

State of the Science in Tracheal Stents: A Scoping Review

OBJECTIVE

Recent material science advancements are driving tracheal stent innovation. We sought to assess the state of the science regarding materials and preclinical/clinical outcomes for tracheal stents in adults with benign tracheal disease.

METHODS

A comprehensive literature search in April 2021 identified 556 articles related to tracheal stents. One-hundred and twenty-eight full-text articles were reviewed and 58 were included in the final analysis. Datapoints examined were stent materials, clinical applications and outcomes, and preclinical findings, including emerging technologies.

RESULTS

In the 58 included studies, stent materials were metals (n = 28), polymers (n = 19), coated stents (n = 19), and drug-eluting (n = 5). Metals included nitinol, steel, magnesium alloys, and elgiloy. Studies utilized 10 different polymers, the most popular included polydioxanone, poly-l-lactic acid, poly(d,l-lactide-co-glycolide), and polycaprolactone. Coated stents employed a metal or polymer framework and were coated with polyurethane, silicone, polytetrafluoroethylene, or polyester, with some polymer coatings designed specifically for drug elution. Drug-eluting stents utilized mitomycin C, arsenic trioxide, paclitaxel, rapamycin, and doxycycline. Of the 58 studies, 18 were human and 40 were animal studies (leporine = 21, canine = 9, swine = 4, rat = 3, ovine/feline/murine = 1). Noted complications included granulation tissue and/or stenosis, stent migration, death, infection, and fragmentation.

CONCLUSION

An increasing diversity of materials and coatings are employed for tracheal stents, growing more pronounced over the past decade. Though most studies are still preclinical, awareness of tracheal stent developments is important in contextualizing novel stent concepts and clinical trials. Laryngoscope, 2021.

Retrievable covered metallic segmented Y airway stent for gastrorespiratory fistula of carina or main bronchi

OBJECTIVE

To evaluate the feasibility of new retrievable covered metallic segmented Y airway stents modified with 3-dimensional (3D) printing for gastrorespiratory fistula involving carina or main bronchi.

METHODS

We designed a new retrievable covered metallic segmented Y airway stent to fit the anatomical characteristics of the carina region in individual patients. All stents were individually customized based on a 3D-printed mold. Six patients with gastrorespiratory fistula and aspiration pneumonia after esophagectomy underwent the stent implantation. The stents were retrieved when the fistula was cured or stent-related complications occurred.

RESULTS

Seven Y stents were successfully implanted and removed in 6 patients. All stents expanded well, and the fistulas were completely sealed. Aspiration pneumonia was controlled in 6 patients. The median Karnofsky Performance Status scores significantly improved after stenting compared with those before stent implantation (P = .024). Sputum retention was the most common complication after stenting and was treated with aspiration under bronchoscopy (33.33%). Excessive granulation tissue proliferation was found in 1 patient (16.7%) and was treated with cryotherapy. The indwelling time of the stent was 64 days (interquartile range, 52-69 days). After stent removal, bronchoscopy, gastroscopy, and computed tomography of the chest showed cured fistulas in all patients, and no stents showed fractures.

CONCLUSIONS

Retrievable covered metallic segmented Y airway stents modified with 3D printing appear to be feasible for the treatment of gastrorespiratory fistula involving carina or main bronchi.

Long-term follow-up of self-expandable metallic stents in benign tracheobronchial stenosis: a retrospective study

BACKGROUND

Self-expandable metallic stents (SEMSs) have enabled a approving management of malignant airway stenosis. However, the long-term efficacy and safety of this treatment in patients with benign airway stricture are unclear. We conducted this study to retrospectively determine the efficacy and long-term outcomes in patients who have undergone SEMS placement for benign tracheobronchial stenosis.

METHODS

All patients treated with SEMSs from July 2003 to June 2016 were reviewed for symptomatic response, complications, and long-term outcomes.

RESULTS

Total 131 stents were successfully deployed in 116 patients. Ninety-eight patients demonstrated clinical improvement after stent insertion (84.48%; 95% confidence interval [CI]: 77.89-91.07). Compared with uncovered stents, covered stents were associated with more sore throats complaints or chest pain (13.89% versus 28.81%, P = 0.036) and with higher incidences of major and minor granulation tissue formation and with recurrent stenosis (4.17% versus 15.25%, P = 0.029; 11.11% versus 37.29%, P < 0.0001 and 9.72% versus 28.81%, P = 0.005, respectively). Each covered and uncovered stent developing tissue hyperplasia required a median of 2 (range: 1-15) and 1(range: 1-7) fibrobronchoscope with electrocautery therapy, respectively. At follow-up (median: 1276 days; range: 2-4263), 68 patients had complete resolution, 15 remained under interventional treatment, 8 had bronchial occlusions, 7 underwent surgery, 14 were lost to follow-up, and 4 died of stent unrelated causes.

CONCLUSION

SEMS placement achieved most clinical improvement among patients in our study, if adequate endotracheal measures were used to address stent-related complications. The use of permanent SEMSs for benign tracheobronchial stenosis was effective and safe for the majority of patients in a long-term follow-up.

TRIAL REGISTRATION

The study has been retrospectively registered in the China Clinical Trial Registry on October 21, 2018 (Registry ID: ChiCTR1800019024 ).

A pilot study of a novel biodegradable magnesium alloy airway stent in a rabbit model

OBJECTIVE

To preliminarily investigate the feasibility of bioabsorption tracheal stenting for the therapeutic application of congenital tracheal stenosis (CTS).

STUDY DESIGN

Experimental research.

SETTING

Shanghai Children Medical Center, National Children's Medical Center.

SUBJECTS AND METHODS

Five kinds of magnesium alloys with different compositions were studied in this paper, a patented Mg-Nd-Zn-Zr alloy series namely JDBM (JiaoDa BioMg) and four Mg-Ca-Zn alloys. The cytotoxicity of alloys was evaluated by the MTS ([3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) assay in rabbit tracheal epithelial cells. Specific magnesium alloys had been immersed in the cell culture medium for 24 h. The tracheal stents that were made of magnesium alloy were implanted into the trachea of New Zealand rabbits and the ablation of the stent was monitored by fiber bronchoscopy. The routine blood examination was conducted prior to and following the stent placement. The rabbits were euthanized following 2-3 months of stenting. H&E staining of the main organs was conducted and the induction of apoptosis of the tracheal tissues was monitored.

RESULTS

The cytotoxicity of the JDBM magnesium alloy was mild and lower than the remaining 4 alloys. The stents were placed successfully in five animals. The tracheal stents were successfully placed and gradually biodegradated as monitored by fiber bronchoscopy; no significant systemic inflammatory response was noted. No significant differences in the liver and/or kidney function prior to and following stent placement were noted. H&E staining indicated the absence of pathological changes in the trachea, liver, heart and/or kidney tissues. The apoptotic assay indicated that the apoptosis ratio of the tracheal tissues was comparable between rabbits with and without tracheal stenting.

CONCLUSION

The results suggested the feasibility of bioabsorption stents made of biodegradable magnesium alloys using in patients with tracheal stenosis, especially in infants.

Combined airway and esophageal stents implantation for malignant tracheobronchial and esophageal disease: A STROBE-compliant article

We aimed to evaluate the safety and efficacy of combined airway and esophageal stents under fluoroscopy guidance and local anesthesia for patients with malignant tracheobronchial and esophageal disease. This retrospective analysis included 35 consecutive patients underwent combined stenting from March 2012 to August 2016. All patients underwent chest computed tomography scans before stenting and during follow-up. Thirty-nine airway stents and 43 esophageal covered stents were implanted. The indication of stenting, technical success and postinterventional complications were collected and analyzed. Thirty-nine airway stents and 43 esophageal covered stents were implanted. Stenting failed in 1 airway stent, and 2 esophageal stents, with technology success rates of 97.4% and 95.3%, respectively. No procedure-related death occurred, only 1 patient died from failure of respiration due to esophagotracheal fistula. The median interval between 2 stenting was 13.0 days. Both dyspnea and dysphasia were significantly relieved after stenting. Restenosis after stenting (7.7%) was the most common complication for airway stenting, all these cases required second stenting. Stent migration (7.0%) was the most common complication after esophageal stenting, 1 case had to receive airway stenting and 1 case received replacement of esophageal stent. During follow up, 23 patients were clinically cured, 2 patients were improved in symptoms, and 1 was invalid. Eight deaths were found in total. The 1-year, 3-year, and 5-year survival rates were 82.4%, 78.8%, and 78.8%, respectively. In conclusion, combined airway and esophageal stents implantation under fluoroscopy guidance and local anesthesia are safe and effective for malignant tracheobronchial and esophageal disease.

Metallic stent insertion and removal for post-tracheotomy and post-intubation tracheal stenosis

PURPOSE

To study the safety and effectiveness of fluoroscopic insertion and removal of self-expandable metallic airway stent for post-tracheotomy tracheal stenosis (PTTS) and post-intubation tracheal stenosis (PITS).

METHODS

We conducted a retrospective analysis of 32 patients who underwent fluoroscopic stenting from September 2011 to March 2017. The patients ranged in age from 12 to 69 years. Thirty-eight airway stents were implanted, 35 covered stents and three bare stents. Nineteen airway stents were used for 16 cases of PITS or PTTS. All patients underwent chest CT scans with/without bronchoscopy prior to stent removal. The indication of stent removal and post-interventional complications were analyzed.

RESULTS

All 38 airway stents were successfully inserted. Insufficient expansion and tissue hyperplasia were most common complications after stenting. Thirty five of 38 airway stents were successfully removed fluoroscopically, with a technical success rate of 92.1%. Routine removal was performed after 2.9 ± 0.3 months, and stent restenosis was found after a mean duration of 2.7 ± 0.3 months. There were six complications of stent removal with no death. Four stents showed strut fracture after removal, of which three stent pieces retained. Two patients showed dyspnea immediately after removal and required mechanical ventilation in PTTS. One patient with PTTS lost of follow-up during a mean period of 33.7 ± 3.9 months. The one-, three- and five-year patency rates were 87.1%, 76.2% and 70.8%, respectively. There was no significant difference between PITS and PTTS.

CONCLUSIONS

Fluoroscopic insertion and removal of airway stent is safe and effective for PITS and PTTS. A three-month retention time is reasonable for airway stents.

The evaluation and surgical management of post-intubation tracheal strictures at a thoracic surgery referral centre in South Africa

Background

The surgical treatment of tracheal stenosis following endotracheal intubation or tracheostomy is well described in the developed world.

Objectives

To describe our surgical experience with this pathology, and highlight the nuances of its diagnosis and management in South Africa.

Methods

We reviewed the clinical records and archived imaging of all patients who underwent tracheal resection and reconstruction for post-intubation tracheal stenosis between 1 July 2003 and 31 July 2014 in the Department of Cardiothoracic Surgery at Inkosi Albert Luthuli Central Hospital, Durban, South Africa.

Results

During the study period, 42 patients underwent tracheal resection. We evaluated the preoperative bronchoscopic characteristics of the tracheal stricture in all patients, and computed tomography (CT) was used as an adjunct in 28 (66%) patients. The stricture lengths determined by CT and intraoperative measurement were strongly correlated (r (27)=0.506, p=0.006), and the stricture lengths determined by bronchoscopy and intraoperative measurement were weakly correlated (r (41)=0.201, p=0.209). A total of 36 patients (85.7%) underwent surgery via a cervical approach and 6 (14.3%) via a right thoracotomy approach. There was no early mortality, and surgery was complicated by vocal cord palsy in 4 cases, restenosis in 2 cases, infection in 1 case and paraparesis in 1 case.

Conclusion

Tracheal resection for the treatment of post-intubation tracheal stenosis can be undertaken safely with minimal complications in the developing world, with the vast majority of lesions approached via a cervical approach. A preoperative evaluation of the stricture using CT is an accurate technique for planning tracheal resection and reconstruction.

Fully Covered Metallic Stents for the Treatment of Benign Airway Stenosis

Introduction. We herein report our experience with new fully covered self-expanding metallic stents in the setting of inoperable recurrent benign tracheobronchial stenosis. Methods. Between May 2010 and July 2014, 21 Micro-Tech® FC-SEMS (Nanjing Co., Republic of Korea) were placed in our hospital in 16 patients for inoperable, recurrent (after dilatation), and symptomatic benign airway stenosis. Their medical files were retrospectively reviewed in December 2014, with focus on stent's tolerance and durability data. Results. Twenty-one stents were inserted: 13 for posttransplant left main bronchus anastomotic stricture, seven for postintubation tracheal stenosis, and one for postlobectomy anastomotic stricture. Positioning was easy for all of them. Stents were in place for a mean duration of 282 days. The most common complications were granulation tissue development (35%), migration (30%), and sputum retention (15%). Fifty-five % of the stents (11/20) had to be removed because of various complications, without difficulty for all of them. None of the patients had life-threatening complications. Conclusion. Micro-Tech FC-SEMS were easy to position and to remove. While the rate of complications requiring stent removal was significant, no life-threatening complication occurred. Further studies are needed to better define their efficacy and safety in the treatment of benign airway disease.

Subcarinal ventilation-assisted Y-shaped stent insertion under local anesthesia for patients with complex tracheobronchial stenosis: initial clinical experience

PURPOSE

We aimed to report our preliminary results of subcarinal ventilation-assisted Y-shaped stent insertion under local anesthesia for patients with complex lower tracheal-carinal-main bronchial complex stenosis.

MATERIALS AND METHODS

Seven consecutive patients with lower tracheal-carinal-main bronchial complex stenosis underwent Y-shaped stent insertion under local anesthesia. During the procedure, subcarinal ventilation was performed using a 4 F angiographic catheter, and stent insertion was performed under the protection of ventilation. Data on technical success, clinical outcome, and follow-up were collected and analyzed.

RESULTS

Subcarinal ventilation-assisted Y-shaped stent insertion under local anesthesia was technically successful in all patients without any major procedure-related complications. Seven stents were inserted in seven patients. Respiratory function improved in all patients, with the Hugh-Jones classification of respiratory status improving from grade IV-V before stenting to grade I-II after stenting. During the follow-up, one patient experienced re-stenosis of the stent. Average survival time was 185.7 days (range, 96-285 days) after the stenting procedure.

CONCLUSION

Subcarinal ventilation-assisted Y-shaped stent insertion under local anesthesia can be an effective, simple, and safe method for lower tracheal-carinal-main bronchial complex stenosis.

The use of self-expandable metallic stents in the airways in the adult population

The airway stents restore patency in the face of luminal compromise from intrinsic and/or extrinsic pathologies. Luminal compromise beyond 50% often leads to debilitating symptoms such as dyspnea. Silicone stents remain the most commonly placed stents worldwide and have been the "gold standard" for the treatment of benign and malignant airway stenoses over the past 20 years. Nevertheless, silicone stents are not the ideal stents in all situations. Metallic stents can serve better in some selected conditions. Unlike silicone stents, there are large and increasing varieties of metallic stents available on the market. The lack of prospective or comparative studies between various types of metallic stents makes the choice difficult and expert-opinion based. International guidelines are sorely lacking in this area.