Tracheal Stent Research Articles

Central airway stenting in oncology

Introduction. Malignant central airway obstruction and malignant tracheoesophageal fistula in the context of tumor development are potentially life-threatening conditions which usually require immediate intervention. Airway stenting is one of the safest and most effective methods of airway patency restoration in patients with malignant obstruction of the central airways and restoration of continuity in patients with malignant tracheoesophageal fistula.Aim. To evaluate the significance of self-expandable metal stents in palliative treatment of patients with malignant central airway obstruction and malignant tracheoesophageal fistula.Materials and methods. Between 2017 and 2021 at the N. N. Blokhin National Medical Research Center of Oncology, 55 patients were observed and treated and underwent trachea stenting per the results of bronchoscopy in combination with esophagogastroduodenoscopy. The 1st group included 25 patients with malignant tracheoesophageal fistulas, the 2nd group included 30 patients with malignant central airway obstruction.Results. In the 1st group, stenting was successful in 25 (100 %) cases which allowed to adequately seal the fistula. Stent migration was observed in 1 (4 %) patient with tracheoesophageal fistula in the context of stenosing cancer of the thoracic esophagus. In the 2nd group, stenting was successful in 30 (100 %) cases. Stent migration was not observed in this patient group. In both groups, there were no complications after stent implantation. Installation of tracheal stent allowed to improve patients’ quality of life and provide a possibility for successful special treatment through low-trauma manipulation.Conclusion. According to the obtained data, endoscopic trachea stenting is the most important method of palliative treatment of tumor-related trachea lesions with development of tracheoesophageal fistulas, malignant central airway obstructions and associated sub- and decompensated pulmonary insufficiency.

CODE BLUE in a patient with tracheal stent: Are we fully equipped?

Sir, Airway stents have long been used to maintain luminal integrity of compromised airway in case of obstruction and malignancy.[1] The complications associated with airway stent placement are malposition, haemorrhage, airway rupture during placement, migration, impaction, formation of granulation tissue, and stent fracture.[2] We present here a challenging case of an airway emergency in a patient with a tracheal stent inserted for a malignancy. A 29-year-old woman diagnosed with adenoid cystic carcinoma of trachea 2 years back had undergone debulking of tumor, tracheal stenting with a metallic stent, and chemo-radiotherapy elsewhere. On the second day of admission, CODE BLUE was activated in view of acute onset biphasic stridor, with air hunger and low oxygen saturation. Despite resuscitation measures, the patient had persistent tachycardia, tachypnea, and hypoxia with non-rebreathing mask (15 L/min of O2). A review of Computed Tomography (CT) neck revealed a tracheal narrowing 1.7 cm distal to vocal cords with narrowest diameter of 6 mm [Figure 1a], complicating an imminent intubation for the patient. She was pre-oxygenated with a non-invasive ventilation mask. Intravenous boluses of fentanyl 75 mcg, muscle relaxant (suxamethonium 100 mg) was given and intubated with a 5.0 mm ID cuffed endotracheal (ET) tube through direct laryngoscopy. A chest x-ray confirmed the position of the ET tube but it fell short of bypassing the tracheal stent, which was reflected in decreased tidal volumes and increased peak pressure. As the length of the 5.0 mm ET tube (23 cm) was not enough to bypass the stent, we had to increase the length by rail roading another 6.5 mm ID tube at the distal end, after removing the connector [Figure 1b]. This step significantly improved the tidal volumes (350-400 ml) without much rise in peak pressure with marked improvement in the oxygenation of patient in the blood gas analysis. Patient underwent bronchoscopic biopsy and excision of mass around the stent after putting on veno-venous extracorporeal membrane oxygenation for oxygenation. Post-procedure ET tube was removed after suctioning and intubated with 7.0 mm ID ET tube for postoperative ventilation and eventually extubated.Figure 1: (a) image showing CECT neck with tracheal stent in situ. (b) image showing the proximal end of 6.5 mm ID tube is cut and railroaded over 5.0 mm ID tube to increase the lengthSecuring airway in an in-hospital CODE blue needs quick thinking and swift action. This case highlights a unique situation where a tracheal stent precluded a “conventional intubation.” A tracheostomy could damage the stent and a supraglottic airway device risked aspiration.[3] A fibre-optic bronchoscope is essential and the best available option to ensure correct position of the tube within the stent or just above the stent. It can also avoid stent-related complications but is not readily available everywhere.[4] No formal guidelines are available in terms of airway management with tracheal stents in situ. A literature search also revealed paucity of data with regard to management in similar case scenarios. Microlaryngeal surgery (MLS) tubes can be made available in the CODE BLUE kits anticipating such scenarios, as they are longer than conventional ET tubes with same internal diameter.[5] This case though uncommon highlights the need to incorporate airway management in cases of tracheal stents as part of our teaching curriculum. Declaration of patient consent The authors certify that they have obtained all appropriate patient consent forms. In the form the patient(s) has/have given his/her/their consent for his/her/their images and other clinical information to be reported in the journal. The patients understand that their names and initials will not be published and due efforts will be made to conceal their identity, but anonymity cannot be guaranteed. Financial support and sponsorship Nil. Conflicts of interest There are no conflicts of interest.

No: 3306 Effectiveness of vivasight single lumen tube in ensuring airway safety during tracheal stent replacement in a complicated tracheo-esophageal fistula

No: 3306 Effectiveness of vivasight single lumen tube in ensuring airway safety during tracheal stent replacement in a complicated tracheo-esophageal fistula

Case series: Montgomery T-tube placement for subglottic tracheal stenosis: a report of 3 cases.

Subglottic tracheal stenosis is stenosis of the trachea between the vocal cords and the lower margin of the cricoid cartilage. The Montgomery T-tube is used as a tracheostomy tube and a combined tracheal stent to avoid postoperative tracheal stenosis. Because the stenosis is close to the glottis, surgical treatment is complex, and many complications may arise. Subglottic tracheal stenosis. The patients underwent endotracheal intubation or tracheotomy because of acute pancreatitis, laryngeal malignancy, or cerebral hemorrhage after endotracheal intubation or tracheotomy and presented with varying degrees of tracheal stenosis and dyspnea. We relieved airway stenosis and improved dyspnea in these 3 patients by placing a Montgomery T-tube. None of the 3 patients had intraoperative complications. In 2 of the cases, airway secretions were stored after surgery. Montgomery T-tube placement is safe and effective for patients with complex subglottic tracheal stenosis.

Efficacy of stent placement in treatment of malignant tracheoesophageal fistula and relevant factors of fistula closure

Objective: To investigate the efficacy of stent placement in the treatment of malignant tracheoesophageal fistula (MTEF) and the factors affecting the closure of the fistula. Methods: Clinical, pathological, laboratory, and imaging data of 288 patients with MTEF admitted to Zhongda Hospital, Southeast University from 2015 to 2021were retrospectively analyzed. Among them, there were 208 males; the age was (63.6±10.5) years. A total of 94 patients received conservative treatment (conservative group), and 194 in the stent group (170 cases with esophageal stents and 24 cases with tracheal stents). Patients were followed-up at 2 weeks, 1 month, 3 months, and 6 months to evaluate the effect of stent implantation. Multivariable logistic regression was used to analyze factors affecting fistula closure. Results: Age, fistula size, leukocyte count before treatment, and fistula location were significantly different between the conservative group and the stent group (P<0.05). The Karnofsky functional status (KPS) score before treatment in the conservative group was lower than the stent group, (45.1±1.0) vs (51.8±0.7) scores, respectively (P<0.001). After 2 weeks and 1 month of treatment, improvement in KPS scores was significantly better in the stent group than in the conservative group (P<0.05). At 1 month, the pulmonary infection rate in the stent group was 33.5% (58/173), significantly lower than that in the conservative group [77.0% (47/61); P<0.001]. Among the 288 patients, the fistula was closed in 196 patients and unclosed in 92 patients. Fistula size (OR=3.429, 95%CI: 1.623-7.829, P=0.001), leukocyte count before treatment (OR=1.160, 95%CI: 1.027-1.317, P=0.018), KPS score before treatment (OR=0.898, 95%CI: 0.848-0.945, P<0.001) and the treatment method (conservative treatment as reference, esophageal stent OR=0.010, 95%CI: 0.004-0.030, P<0.001; tracheal stent OR=0.003, 95%CI: 0.000-0.042, P<0.001) were factors affecting fistula closure. In the 170 patients in the esophageal stent group, early complications (≤24 h) occurred in 71 patients, and late (>24 h) complications occurred in 11 patients. While in the 24 patients in the tracheal stent group, 9 had early complications and 2 had late complications. Conclusions: Stent placement is an effective treatment for MTEF compared to conservative treatment. Stent treatment, small fistula size, low pre-treatment leukocyte count, and high pre-treatment KPS score are beneficial to fistula closure.

The methodological aspects and results of combined tracheal and esophageal stenting in locally advanced malignant tumors of the lung, esophagus, and mediastinum. A multicenter study

The methodological aspects and results of combined tracheal and esophageal stenting in locally advanced malignant tumors of the lung, esophagus, and mediastinum. A multicenter study

Treatment of cicatricial tracheal stenosis and tracheoesophageal fistula in patients with COVID-19 pneumonia

To describe treatment of cicatricial tracheal stenosis and tracheoesophageal fistula in patients with COVID-19 pneumonia. There were 91 patients with cicatricial tracheal stenosis for the period from August 2020 to April 2022 (21 months). Of these, 32 (35.2%) patients had cicatricial tracheal stenosis, tracheoesophageal fistula and previous coronavirus infection with severe acute respiratory syndrome. Incidence of iatrogenic tracheal injury following ventilation for viral pneumonia in the pandemic increased by 5 times compared to pneumonia of other genesis. Majority of patients had pneumonia CT grade 4 (12 patients) and grade 3 (8 patients). Other ones had pulmonary parenchyma lesion grade 2-3 or mixed viral-bacterial pneumonia. Isolated tracheoesophageal fistula without severe cicatricial stenosis of trachea or esophagus was diagnosed in 4 patients. In other 2 patients, tracheal stenosis was combined with tracheoesophageal fistula. Eight (25%) patients had tracheostomy at the first admission. This rate was almost half that of patients treated for cicatricial tracheal stenosis in pre-pandemic period. Respiratory distress syndrome occurred in 1-7 months after discharge from COVID hospital. All patients underwent surgery. In 7 patients, we preferred palliative treatment with dilation and stenting until complete rehabilitation. In 5 patients, stent was removed after 6-9 months and these ones underwent surgery. There were 3 tracheal resections with anastomosis, and 2 patients underwent tracheoplasty. Resection was performed in 3 patients due to impossible stenting. Postoperative course in these patients was standard and did not differ from that in patients without viral pneumonia. In case of tracheoesophageal fistula, palliative interventions rarely allowed isolation of trachea. Four patients underwent surgery through cervical approach. There were difficult surgeries in 2 patients with tracheoesophageal fistula and cicatricial tracheal stenosis. One of them underwent separation of fistula and tracheal resection via cervical approach at primary admission. In another patient with thoracic fistula, we initially attempted to insert occluder. However, open surgery was required later due to dislocation of device. Absolute number of patients with tracheal stenosis, tracheoesophageal fistula and previous COVID-19 has increased by several times compared to pre-pandemic period. This is due to greater number of patients requiring ventilation with risk of tracheal injury, non-compliance with preventive protocol for tracheal injury including anti-ischemic measures during mechanical ventilation. The last fact was exacerbated by involvement of allied physicians with insufficient experience of safe ventilation in the «red zone», immunodeficiency in these patients aggravating purulent-inflammatory process in tracheal wall. The number of patients with tracheostomy was 2 times less that was associated with peculiarity of mechanical ventilation in SARS-CoV-2. Indeed, tracheostomy was a poor prognostic sign and physicians tried to avoid this procedure. Incidence of tracheoesophageal fistula in these patients increased by 2 times compared to pre-pandemic period. In subacute period of COVID-associated pneumonia, palliative measures for cicatricial tracheal stenosis and tracheoesophageal fistula should be preferred. Radical treatment should be performed after 3-6 months. Absolute indication for circular tracheal resection with anastomosis is impossible tracheal stenting and ensuring safe breathing by endoscopic methods, as well as combination of cicatricial tracheal stenosis with tracheoesophageal fistula and resistant aspiration syndrome. Incidence of postoperative complications in patients with cicatricial tracheal stenosis and previous mechanical ventilation for COVID-19 pneumonia and patients in pre-pandemic period is similar.

Integrated endoscopic treatment of primitive unresectable tracheal tumor: the INTACT retrospective cohort study.

Primitive tracheal tumors represent a rare entity whose management, when unresectable, remains challenging. Primary aim of this study was to explore the survival and the factors influencing prognosis of patients with unresectable primitive tracheal tumor undergoing multimodal treatment integrating interventional bronchoscopy and radiotherapy. This retrospective cohort study was conducted at the University Hospital of Modena (Italy) over a 12-year period (January 2010 to January 2022) analyzing patients with unresectable primary tracheal tumor receiving interventional bronchoscopy treatment followed by radiotherapy. Survival analysis was conducted for the whole population and according to histology, development of metastasis, stent placement and the onset of disease relapse. The raw and independent association between potential risk factor and 5-year mortality and the reported complications were investigated. A total of 12 patients were included. Five-year survival rate was 42% with a median survival time of 26.7 (interquartile range, 4.1-82) months. Survivors showed a higher prevalence of cystic-adenoid histology (80% vs. 14%), while patients who were dead at 5 years were those with a more advanced T (prevalence of T2: 71% vs. 0%) and a lower response to first line treatment (57% vs. 0%). Treatment complications accounted for stent dislocation (33%) and the onset of granuloma (18%), while no major side effects were reported. The presence of cystic-adenoid histology resulted in significantly improved 5-year survival rate (80% vs. 14%). The onset of distal metastasis, the occurrence of disease relapse and the placement of tracheal stent did not result significantly associated with lower survival. Among analysed variables, only the presence of cystic-adenoid histology resulted independently associated with survival (odds ratio =0.1, P=0.04). Multimodal treatment including interventional bronchoscopy and associated radiotherapy for unresectable primary tracheal tumors seems not burdened by significant complications and may provide benefits in terms of survival for those patients with cystic-adenoid histology.

Investigation on forced vibration characteristics of Nitinol tracheal stent.

Tracheal stents can be placed in a narrow position in the human trachea to ensure smooth breathing. And the stent will deform during service by the influence of the physiological environment or random excitations, such as coughing. This paper divides the vibration into periodic and random vibrations according to the different pressures. And a coupling vibration model was established by analyzing the contact relationship between the stent and the trachea tissue. And this study discusses the influence of tracheal diameter, respiratory pressure, and frequency on the stent vibration characteristics through Ansys simulation. In addition, the nonlinear equations were solved by the Matlab numerical analysis method, which could help analyze the influence of cough intensity on the stability of the tracheal stent system. The results showed that when tracheal stenosis occurred in the trachea's more significant grade, the trachea stent was more likely to fall off when treated with a tracheal stent. With the increase in respiratory frequency and pressure, the deformation of the tracheal stent is more considerable. Moreover, the frequency of normal cough hardly affects the stability of the stent system, while the excitation force and damping coefficient value greatly influence the system. When the excitation force of the cough exceeds the critical importance of 20N, the tracheal stent is prone to fall off. This study comprehensively obtained the forced vibration characteristics of the stent under service conditions, which could make up for the shortage of the vibration theory of the stent. The results can provide a theoretical basis for predicting the possibility of stent loss in clinical treatment.

Patient-Specific Stent Fabrication Using a Seven-Degree-Of-Freedom Additive Manufacturing System

With advances in additive manufacturing technologies, the creation of medical devices which are tailored to the geometry of a patient’s unique anatomy is becoming more feasible. The following paper details the capabilities of a seven-degree-of-freedom fused filament deposition modeling system which enables a wide variety of user-control over previously restricted parameters, such as nozzle angle, print bed rotation, and print bed tilt. The unique capabilities of this system will be showcased through the production of a patient-specific tracheal stent using three different methods: segmented overmolding, transverse rastering, and longitudinal rastering. The resulting opportunities and time savings demonstrated by the prints will provide a case for greater implementation of seven-degree-of-freedom manufacturing technologies.

Related factors and prognosis analysis of esophagorespiratory fistula after esophageal cancer surgery

Objective: To explore the factors associated with the development of esophagorespiratory fistula (ERF) after esophageal cancer surgery and its relationship with patient survival. Methods: A total of 241 patients with esophageal cancer after surgery, who received postoperative sputum suction through bronchoscope from West China Hospital of Sichuan University between January and December 2021 were included. The clinical data and airway features under bronchoscope of these patients were collected. Of the 241 patients, 203 were males (84.2%) and 38 were females (15.8%), aged (63.63±8.05) years. The related factors of ERF were analyzed by multivariate logistic regression analysis, and Kaplan-meier was used to analyze the relationship between bronchoscopic specific manifestations, treatment modality and patient survival. Results: Of the 241 postoperative patients with esophageal cancer, 21 (8.7%) developed ERF. There were 39 (16.2%) patients with bronchoscopic specific manifestations, including 16 cases (6.6%) of hyperemia, 13 cases (5.4%) of congestion, and 15 cases (6.2%) of erosion. Bronchoscopic specific manifestations of tracheal mucosa (OR=13.734, 95%CI: 3.535-29.074, P<0.001) and thoracotomy (OR=9.121, 95%CI 1.843-44.237, P=0.007) were independent risk factors for the development of ERF, and preoperative chemotherapy (OR=0.128, 95%CI: 0.052-0.607, P=0.006) was a protective factor in the occurrence of ERF. The median survival time was 224 (95%CI: 95-353)d in the stent-treated group (14 patients) after the onset of ERF, and the median survival time of patients in the supportive care group (7 patients) was 29 (95%CI: 8-50)d, and the survival difference was statistically significant (χ2=5.69, P=0.017). Conclusions: Bronchoscopic specific manifestations are independent risk factors for the development of ERF in postoperative patients with esophageal cancer and are useful in assessing the risk of developing ERF. After the occurrence of postoperative ERF, timely intervention by insertion of tracheal stents to seal the fistula may prolong the survival time of the patients.

A Review of Recent Patents on Structures Related to Tracheal Stents

Background: The trachea is an important part of the respiratory system. Long-term airway diseases and the effects of human physiological conditions can cause trachea stenosis. This will seriously affect patients’ physical health. Tracheal stents can provide durable support by means of dilating the narrowed area; they can effectively relieve the patient's breathing difficulties, which is of value that is more practical. Objective: To meet the vital requirements for better adaptation to the human airway environment and prevent complications associated with stent placement, the construction and materials of tracheal stents have been improved constantly. Methods: This paper investigates various representative patents related to the tracheal stent. The structure type, placement method and applications situation of these tracheal stents are discussed. Results: The characteristics of different types of tracheal stents are analyzed. This paper analyzes the main problems in its development. The solutions to the issues and the current and future research on tracheal stents are discussed. Conclusion: The tracheal stents are classified into metal stent, silicone stent, biodegradable stent and hybrid material stent. Further improvements are needed in the aspects of structural design, safety, applicability, biocompatibility, algorithm of drive model of tracheal stent. More related patents about tracheal stents need to be developed.

ODP473 Critical Airway Obstruction Resolving with Medical Management of Newly Diagnosed Thyroid Lymphoma

Abstract Background Thyroid lymphoma is a rare malignancy that accounts for 1-5% of thyroid malignancies. The classic presentation of thyroid lymphoma is a rapidly enlarging, painless goiter. The main modalities used to confirm lymphoma are thyroid ultrasound and FNA. We report a case of critical airway obstruction (&amp;lt;5 mm) requiring core needle biopsy to diagnose thyroid lymphoma, with resolution of obstruction following chemotherapy. Case A 60-year-old man with a history of hypertension and BPH presented to the hospital with two weeks of progressive shortness of breath and dysphagia. He denied weight loss, night sweats, or thyroid dysfunction. CT demonstrated thyromegaly with substernal extension along with extension into tracheal-esophageal grooves, encasing the trachea with possible right sided tracheal invasion and tracheal narrowing to 4 mm. Thyroid ultrasound demonstrated an enlarged thyroid replaced by heterogenoushypoechoic lobular masses. Additional imaging demonstrated a 4 cm perirenal mass. Laboratory evaluation demonstrated TSH 0.97 uIU/mL (0.4–4. 0 uIU/mL), free T4 0.8 ng/dL (0.6-1.5 ng/dL), anti-TPO 16.9 IU/mL (&amp;lt;5. 0 IU/mL), and LDH 262 U/L (&amp;lt;240 U/L). He underwent a bronchoscopy which showed 60% tracheal obstruction 1 cm below the vocal cords. He underwent 2 FNAs which both resulted as Bethesda 3. The first FNA demonstrated lympho-histiocytic infiltrate, scant spindled cells and follicular cell groups with oncocytic features. The second FNA demonstrated chronic lymphocytic thyroiditis. Due to worsening respiratory status, he was given high dose dexamethasone and planned for tracheal stenting. He subsequently underwent a core needle biopsy demonstrating marked atypical B cell infiltration, concerning for mature large B cell lymphoma. Immunoperoxidase studies demonstrated atypical cells positive for CD10, 20, 79a, BCL-2, 6, and PAX5 with a 90% Ki67 proliferation diagnosing diffuse large B cell lymphoma. Biopsy of his perirenal mass was negative for lymphoma or carcinoma. He began R-CHOP chemotherapy and after one cycle experienced resolution of difficulty breathing, dysphagia, and thyromegaly. Tracheal stenting and thyroidectomy were thus avoided. After 4 cycles of R-CHOP, a PET CT demonstrated no evidence of residual lymphoma. A repeat thyroid ultrasound also demonstrated resolution of both thyromegaly and hypoechoic nodules. Conclusions Patients with a rapidly enlarging goiter and obstructive symptoms should undergo evaluation for thyroid lymphoma, particularly if they have a history of Hashimoto's thyroiditis or positive TPO antibodies even when euthyroid upon presentation. Though FNA is the first line modality used to diagnose thyroid lymphoma, our case highlights the need to proceed with a timely core needle biopsy if FNA is non-diagnostic to obtain a definitive diagnosis. Once the diagnosis of thyroid lymphoma is confirmed, management with R-CHOP chemotherapy rapidly improves obstructive symptoms, avoiding unnecessary surgical intervention even in the setting of critical airway obstruction.

Airway Management of a Patient With Tracheoesophageal Fistula and Tracheal Stent

A 69-year-old male patient, a known case of squamous cell carcinoma of the esophagus on palliative care and Do Not Attempt Resuscitation (DNAR) status, presented for urgent laparoscopic gastrostomy tube insertion under general anesthesia. The patient had developed an iatrogenic tracheoesophageal fistula (TEF) because of the tracheal stent, which was placed for tracheal stenosis. A preoperative assessment was done, and a plan of airway management via one-lung ventilation (OLV) through an endobronchial tube was devised by the anesthesia team and discussed with the surgery team. The airway was secured via asleep fiberoptic right endobronchial intubation using a microlaryngeal tube (MLT) size 6 since there was uncertainty regarding adequate patency of the airway due to the invasion by the tumor and the presence of the stent. The patient remained hemodynamically stable. After surgical incision and insufflation of CO2 in the abdominal cavity, the patient's airway pressures were increased and we were unable to deliver adequate tidal volumes. Surgery was stopped; the presence of a kink in the circuit or endotracheal tube (ETT), the possibility of laryngospasm/bronchospasm, and pneumothorax were ruled out. Fiberoptic bronchoscopy (FOB) revealed that the endobronchial tube was abutting the secondary carina. We pulled the MLT by 2 cm. The rest of the procedure was uneventful and we extubated the patient at the end of the procedure under vision using a fiber optic bronchoscope. The patient was discharged after two days of stay in the hospital. Our patient with TEF and tracheal stent posed a significant challenge for airway management. A thorough plan was drawn up and a team briefing was done. Perioperatively, the difficulty in ventilation was identified, and various other etiologies were ruled out with the successful identification and management of the problem.

T-CELL LYMPHOMA CAUSING CENTRAL AIRWAY OBSTRUCTION TREATED WITH TRACHEOBRONCHIAL SELF-EXPANDING METALLIC STENT

T-CELL LYMPHOMA CAUSING CENTRAL AIRWAY OBSTRUCTION TREATED WITH TRACHEOBRONCHIAL SELF-EXPANDING METALLIC STENT

PITFALLS OF PERCUTANEOUS TRACHEOSTOMY PLACEMENT

PITFALLS OF PERCUTANEOUS TRACHEOSTOMY PLACEMENT

THE NONCOMPLIANT PATIENT WITH THE BROKEN STENT

THE NONCOMPLIANT PATIENT WITH THE BROKEN STENT

Anesthetic management in a patient with severe tracheal stenosis by monitoring oxygen reserve index

BackgroundGeneral anesthesia for tracheal stenting is challenging because of difficult ventilation and accompanying hypoxia. We report the use of oxygen reserve index (ORi™) during tracheal stenting.Case presentationCauterization of an intratracheal tumor and tracheal stenting was scheduled in a patient. ORi decreased from 0.3 to 0.2 after starting cauterization using a flexible bronchoscope through a tracheal tube with 28% oxygen, while SpO2 was maintained at 100%. ORi further decreased to 0, followed by a decrease of SpO2 < 90%, and surgery was interrupted. SpO2 was increased shortly after increasing FiO2 to 1.0, but ORi remained 0 when surgery was resumed; it was increased after completion of cauterization. Both ORi and SpO2 were maintained above 0.4 and 98%, respectively, during tracheal stenting through a rigid bronchoscope under intrapulmonary percussive ventilation.ConclusionORi was useful for predicting a decrease of SpO2 under general anesthesia for tracheal stenting.

The strategy of removing tracheal stents by using an interventional technique under fluoroscopy

BackgroundTracheal stent implantation is widely used in clinic settings. Timely removal of tracheal stents could prevent or reduce related complications. This study was aimed at evaluating the feasibility and safety of removing tracheal stents by an interventional technique under fluoroscopy.MethodsClinical data of patients with self-expanding uncovered tracheal stents removed by an interventional technique under fluoroscopy were analyzed retrospectively, including medical records, imaging findings, surgical records, and follow-up results. According to the type and time of stent placement and the proliferation of granulation tissue under bronchoscopy, different tracheal stent removal techniques were used to remove the tracheal stent under fluoroscopy, and the feasibility and safety of the interventions were analyzed.ResultsIn all, 148 tracheal stents were removed from 112 patients; 95.9% (142/148) of the stents were completely removed and 4.1% (6/148) had a small amount of metal residue, and foreign-body forceps were removed under fiber bronchoscopy guidance. In 78 (69.6%), 32 (21.6%), and 6 (5.4%) patients, the tracheal stent was removed by the internal stripping, direct removal, and stent-in-stent methods, respectively. The overall stent removal time ranged from 11 to 111 (28.9 ± 20.1) min. During stent removal, 16 (14.3%) and 13 (11.6%) patients developed mild and moderate complications, respectively. There were no serious complications such as massive hemorrhage, mediastinal fistula, or death.ConclusionsAn interventional technique under fluoroscopy for stent removal is a feasible, safe, and effective method and could serve as a technique for tracheal stent removal in clinical settings.

Bionic design and performance research of tracheal stent based on shape memory polycaprolactone

Trachea injury caused by tracheomalacia, stenosis or atresia can result in severe dyspnea, even asphyxia. With the development of trachea reconstruction technology, trachea stents have become an alternative treatment method. Here, we fabricated a kind of shape memory PCL/Fe3O4 composites (SMPC-PCL) by mixing different weight fractions of benzoyl peroxide and Fe3O4 nanoparticles. The addition of magnetic nanoparticles endowed SMPC-PCL with the capability of remote non-contact actuation, which exhibited unique advantages in minimally invasive implantation and adaptive ability. Further, based on fully observing the unique reticular structure of glass sponges, two types of biomimetics stents were designed and fabricated, and the mechanical properties were thoroughly investigated by experiments and finite element analysis. The minimally invasive implant performance and biological characterization were carried out to evaluate its availability. The excellent mechanical properties, minimally invasive implant performance and biological properties suggest the application potential in tracheal stents.