Search

Background: Due to the low incidence of malignant tracheoesophageal fistula and the paucity of relevant clinical studies, the benefits of stent implantation have not been well documented. It remains unclear which factors may affect fistula closure. Methods: Between January 2015 and January 2021, 344 patients who were diagnosed with malignant tracheoesophageal fistula at Zhongda Hospital, Southeast University, were retrospectively enrolled. Demographic and clinical data were collected. Risk factors for fistula closure identified by univariate analysis were further analyzed using multivariable logistic regression. Results: A total of 288 patients were analyzed in this study, of which 94 were treated conservatively, 170 were treated with an esophageal stent, and 24 were treated with a tracheal stent. Among them, the delta Karnofsky's performance status score values (after 2 weeks/before treatment [p = 0.0028], after 1 month/before treatment [p = 0.0103]) were significantly different between conservative and stent treatment. There was a significant reduction of pneumonia incidence in the stenting group (33.53%) compared to the conservative treatment group (77.05%) after one month (p <0.0001). In addition, the closure of fistulas was influenced by four independent risk factors: 1) treatment methods (p < 0.0001), 2) fistula size (p = 0.0003), 3) preoperative white blood cell count (p = 0.0042), and 4) preoperative Karnofsky's performance status score (p = 0.0001). Conclusions: Stent implantation has become an effective method for treating malignant tracheoesophageal fistula compared to conservative treatment. Additionally, stent implantation, smaller fistula size, lower preoperative white blood cell count, and higher preoperative Karnofsky's performance status score suggest a better outcome. [ABSTRACT FROM AUTHOR]

Tracheal stents can be used to quickly reconstruct the airway and relieve symptoms of dyspnea in patients with tracheal stenosis. However, existing tracheal stents lead to complications such as granulation tissue formation, difficulty in removal, persistent growth of malignant tumors, stent migration, and mucus plugging. In this article, we reviewed the main methods used to reduce complications associated with tracheal stent design. Drug-eluting stents can inhibit granulation tissue formation and prevent infection and local chemotherapy. The biodegradable stent can support the trachea for some time, maintain tracheal patency, and degrade gradually, which avoids removing or replacing the stent. Radioactive stents loaded with I125 have good potential for inhibiting the persistent growth of malignant tumors. Three-dimensional printing technology enables the manufacturing of patient-specific stents, which increases the degree of matching between the complex tracheal anatomy and the stent, thus providing a new solution for stent migration caused by structural mismatch. Minimizing the barrier of the stent to mucociliary clearance, providing an anti-fouling coating, and culturing respiratory epithelial cells on the surface of the stent are the main methods used to reduce mucus plugging. We also proposed future research directions for tracheal stents to guide the design and manufacture of ideal tracheal stents.

Esophageal stricture is the most common and disabling complication of esophageal injury caused by ingestion of corrosive substances. In our case, the patient developed esophageal stenosis due to ingestion of strong alkaline substances and underwent colon replacement surgery after repeated failed dilation treatments. After surgery, anastomotic stenosis and tracheocolonic fistula occurred successively, and the entire diagnosis and treatment cycle of this disease lasted for more than 20 years. Based on experience and the actual situation of the patient, we conclude that esophageal stents should be the primary treatment option, while tracheal stents should be carefully selected, and secondary surgery is not recommended.

Medical implants with customizable design capabilities are an important direction for high-end medical devices. An important standard in implant design is to match the mechanical properties of the implantation site. Inspired by the ‘cartilage ring-connective tissue’ structure of natural tracheal, we propose a design approach of tracheal stent composed of ‘skeleton + filling matrix’. By establishing a mapping model of structural parameters and J-type response mechanical properties, we realize a larger degree of freedom in adjusting the J-type mechanical properties. This design approach uniquely aligns the mechanical properties of the tracheal stent with those of the native trachea. We provided a thermal field-assisted rotary printing method enabling the integration of both thermoplastic and thermoset materials, which have successfully fabricated this heterogeneous structural stent as a single piece using. Our design methodology is a great inspiration for the development of medical luminal implants with designable and adjustable mechanical properties.

Abstract Background 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. Methods 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. Results 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 20 N, 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. Conclusion The results can provide a theoretical basis for predicting the possibility of stent loss in clinical treatment.

Rigid bronchoscopy is a common procedure for central airway obstructions (CAO). Many patients with advanced lesions causing CAO have tenuous, positionally dependent respiratory status which requires additional procedural considerations. This case report describes a 57-year-old man with high grade epithelioid angiosarcoma of the right lung and pleura who underwent placement of a tracheal stent by rigid bronchoscopy in the novel procedural conditions of right lateral decubitus, semi-sitting position with dexmedetomidine, midazolam, and propofol for moderate sedation. Dexmedetomidine, which is currently in use for flexible bronchoscopy due to its analgesic, anxiolytic, and antisialogogue properties performed ideally and should be further evaluated for this indication.

The patient, a 62-year-old woman, complained chiefly of cough. We planned chemoradiotherapy for squamous nonsmall cell lung cancer. A single dose of 2-Gy irradiation and no anticancer agent administration exacerbated the airway stenosis with severe respiratory failure. Urgent tracheal intubation was performed, and a tracheal stent was implanted under extracorporeal membrane oxygenation (ECMO). Because her performance status (PS) worsened from 1 to 2, we administered radiotherapy. The tumor size decreased. There was no recurrence for the next 3 months, and her PS improved to 1. Emergency tracheal intubation and tracheal stent placement under ECMO can be effective for exacerbated airway obstruction after radiotherapy.

Background: 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. Methods: 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. Results: 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 20 N, 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. Conclusion: The results can provide a theoretical basis for predicting the possibility of stent loss in clinical treatment. [ABSTRACT FROM AUTHOR]

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. [ABSTRACT FROM AUTHOR]

Stent migration is one of the common complications after tracheal stent implantation. The causes of stent migration include size mismatch between the stent and the trachea, physiological movement of the trachea, and so on. In order to solve the above problems, this study designed a non-uniform Poisson ratio tracheal stent by combining the size and structure of the trachea and the physiological movement of the trachea to improve the migration of the stent, meanwhile ensuring the support of the stent. In this study, the stent corresponding to cartilage was constructed with negative Poisson's ratio, and the stent corresponding to the circular connective tissue and muscular membrane was constructed with positive Poisson's ratio. And four kinds of non-uniform Poisson's ratio tracheal stents with different link lengths and negative Poisson's ratio were designed. Then, this paper numerically simulated the expansion and rebound process of the stent after implantation to observe the support of the stent, and further simulated the stretch movement of the trachea to calculate the diameter changes of the stent corresponding to different negative Poisson's ratio structures. The axial migration of the stent was recorded by applying different respiratory pressure to the wall of the tracheal wall to evaluate whether the stent has anti-migration effect. The research results show that the non-uniform Poisson ratio stent with connecting rod length of 3 mm has the largest diameter expansion in the negative Poisson ratio section when the trachea was stretched. Compared with the positive Poisson's ratio structure, the axial migration during vigorous breathing was reduced from 0.024 mm to 0.012 mm. The negative Poisson's ratio structure of the non-uniform Poisson's ratio stent designed in this study did not fail in the tracheal expansion effect. Compared with the traditional stent, the non-uniform Poisson's ratio tracheal stent has an anti-migration effect under the normal movement of the trachea while ensuring the support force of the stent.

The efficacy of tracheal stents (TSs) in treating malignant tracheal stenosis is often compromised by tumor overgrowth, leading to restenosis and other stent-related complications that conventional chemotherapy and commercial stents fail to adequately address. Drug-loaded tracheal stents have the potential to deliver chemotherapeutics directly to tumors while relieving stenosis, but their effectiveness has yet to be studied in vivo. The design of drug-loaded tracheal stents adapting to lesions to achieve optimal antitumor effects and minimal side effects remains an area worth exploring. In this study, a lesion-adaptive bionic tracheal stent (PTX-TS) designed for the dual purpose of treating tracheal tumors and associated stenosis was developed. This novel PTX-TS was evaluated using an orthotopic rabbit model of malignant tracheal stenosis, newly established in this study. The rabbit lesions were precisely scanned using computed tomography (CT) for 3D reconstruction, enabling the design of a PTX-TS that fit both the tumor and airway dimensions to ensure complete tumor coverage and effective dilation of the stenotic airway. The PTX-TS featured a bilayer structure including a surface layer of PTX/ethylene-vinyl acetate copolymer (EVA) blends for sustained PTX release and an inner layer of polycaprolactone (PCL)/EVA blends for appropriate mechanical performance. The stent was fabricated layer by layer using a custom-built 3D printer, and the drug-loaded surface layer was printed using a novel liquid printing technique developed in our lab, achieving a high drug loading of up to 80%. The dose of the PTX-TS was investigated and set as 7.5 mg/cm 2 , which leads to maximum tissue permeation. With its bionic cross-sectional C-shaped structure, the PTX-TS demonstrated excellent radial flexibility, allowing successful implantation at the lesion site using a specially designed delivery apparatus, where it self-expanded to relieve stenosis. Additionally, the PTX-TS effectively delivered PTX directly to the tracheal tumor, resulting in superior antitumor efficacy without significant toxicity or complications.

Objective: Locally aggressive thyroid cancer can result in airway obstruction secondary to tracheal compression or vocal cord palsy. A tracheal stent provides an alternative to surgical resection, tracheostomy or conservative management in patients with compressive symptoms. This systematic review synthesises the current evidence associated with tracheal stenting in locally advanced thyroid cancer. Design, setting and participants: We conducted a systematic review of tracheal stenting in locally advanced thyroid cancers. We searched MEDLINE, Embase and Web of Science for studies until 22 September 2020. Inclusion criteria were studies involving patients who had received tracheal stents to treat laryngotracheal stenosis secondary to locally advanced thyroid cancer. Single case reports or single cases were not included. Main outcome measures: We assessed studies for data on the performance of tracheal stenting; defined as symptomatic relief, spirometry data, complication rates and mortality. We also extracted data pertaining to the use of different types of stent. Results: We identified eight full‐text articles from 325 titles found in our search. These were all single‐centre retrospective studies that lacked homogeneity of thyroid cancer histotypes. The number of patients in each study ranged from 4 to 35 patients. Stenting improved performance status (two of two studies), symptoms (five of five studies) and spirometry (two of three studies). The most common complications were tracheal granulation, tumour overgrowth, stent migration and sputum retention. Conclusion: There is a lack of evidence in the literature of tracheal stents in locally advanced thyroid cancer. However, the evidence available suggests tracheal stenting may be a useful treatment adjunct in advanced thyroid cancer‐causing symptomatic airway obstruction. [ABSTRACT FROM AUTHOR]

Introduction: Without fetal or perinatal intervention, congenital high airway obstruction syndrome (CHAOS) is a fatal anomaly. The ex utero intrapartum treatment (EXIT) procedure has been used to secure the fetal airway and minimize neonatal hypoxia but is associated with increased maternal morbidity. Case Presentation: A 16-year-old woman (gravida 1, para 0) was referred to our hospital at 31 weeks gestation with fetal anomalies, including echogenic lungs, tracheobronchial dilation, and flattened diaphragms. At 32 weeks, fetoscopic evaluation identified laryngeal stenosis, which was subsequently treated with balloon dilation and stent placement. The patient developed symptomatic and regular preterm contractions at postoperative day 7 with persistent sonographic signs of CHAOS, which prompted a repeat fetoscopy with confirmation of a patent fetal airway followed by Cesarean delivery under neuraxial anesthesia. Attempts to intubate through the tracheal stent were limited and resulted in removal of the stent. A neonatal airway was successfully established with rigid bronchoscopy. Direct laryngoscopy and bronchoscopy confirmed laryngeal stenosis with a small tracheoesophageal fistula immediately inferior to the laryngeal stenosis and significant tracheomalacia. A tracheostomy was then immediately performed for anticipated long-term airway and pulmonary management. The procedures were well tolerated by both mom and baby. The baby demonstrated spontaneous healing of the tracheoesophageal fistula by day of life 7 with discharge home with ventilator support at 3 months of life. Conclusion: Use of repeated fetoscopy in order to relieve fetal upper airway obstruction offers the potential to minimize neonatal hypoxia, while concurrently decreasing maternal morbidity by avoiding an EXIT procedure. Use of the tracheal stent in CHAOS requires further investigation. The long-term reconstruction and respiratory support of children with CHAOS remain challenging. [ABSTRACT FROM AUTHOR]

The patient, a 62-year-old woman, complained chiefly of cough. We planned chemoradiotherapy for squamous nonsmall cell lung cancer. A single dose of 2-Gy irradiation and no anticancer agent administration exacerbated the airway stenosis with severe respiratory failure. Urgent tracheal intubation was performed, and a tracheal stent was implanted under extracorporeal membrane oxygenation (ECMO). Because her performance status (PS) worsened from 1 to 2, we administered radiotherapy. The tumor size decreased. There was no recurrence for the next 3 months, and her PS improved to 1. Emergency tracheal intubation and tracheal stent placement under ECMO can be effective for exacerbated airway obstruction after radiotherapy. [ABSTRACT FROM AUTHOR]

Abstract Background Dogs with tracheal stents often have positive airway bacterial cultures. The pathogenicity of these organisms and risk factors for infection have not been investigated. Objective Describe bacterial infection in dogs with tracheal collapse before and after tracheal stent placement. Animals Fifty‐three client‐owned dogs. Methods Retrospective review of medical records of dogs receiving tracheal stents with thoracic radiographs, tracheoscopy, and endotracheal lavage. Results There was no difference between the overall prevalence of dogs with positive bacterial cultures before (31/38; 82%) or after stent placement (24/31; 77%) (P = .67). An increased number of geriatric (17/28; 61%) and traditional‐type collapse (TTC) (16/26; 62%) dogs had positive pathogenic airway infections before stent placement, compared to young (8/25; 32%; P = .04) and malformation‐type collapse (MTC) dogs (9/27; 33%; P = .04). After tracheal stent placement, geriatric dogs had a 52% reduction in pathogenic bacteria infection frequency (P = .02) and dogs with TTC had a 56% reduction in pathogenic bacteria infection frequency (P = .01). Significant risk factors for pathogenic infection included a history of pneumonia (OR = 3.6; 95% CI, 0.28‐43.36) and cardiac disease (OR = 1.25; 95% CI, 0.16‐9.92) in geriatric dogs, and hepatomegaly in young dogs (OR = 1.5; 95% CI, 0.12‐19.44). Conclusions and Clinical Importance Tracheal stent placement does not increase the overall rate of pathogenic bacterial infection in dogs with tracheal collapse and can decrease the rate of subsequent pathogenic infections in geriatric dogs and dogs with TTC that require tracheal stenting. Airway culture and cytology should be performed in all dogs undergoing tracheal stent placement.

Introduction. Currently, there is a tendency for a number of post-intubation patients to develop post-tracheostomic cicatricial stenosis of the trachea. This dictates a need for the improvement of surgical and anaesthesiologic approaches to intubation management. Objective: Analysis of the specific parameters of anesthesia for cervical tracheal resection in patients with stenosis of the trachea without its intubation.Subjects and methods. We analyzed 12 cases of circular resection of the trachea due to benign stenosis. The degree of anesthetic risk was as follows: 11 patients – ASA 3, 1 patient – ASA 4. Tracheal stenosis persisted for 14±6 months before it was resected (Me 4, Min 1, Max 67). The length of the resected part of the trachea was 27±3 mm (Me 25, Min 15, Max 40), duration of surgery – 159±9 min (Me 160, Min 65, Max 240). The anesthesia strategy included the insertion of the I-Gel supraglottic airway device with a jet ventilation catheter put through the I-Gel. Temporary stenting of the stenosis zone of the trachea before surgery (if necessary) instead of bougienate was an important component of the anesthesia strategy. Mandatory use of sedation (dexmedetomidine) is suggested before and within 12 hours after surgery.Results. This strategy can be successfully implemented if the minimum diameter of the tracheal stenosis exceeds 7 mm (the jet ventilation catheter is necessary to be applied through this lumen and a fine bronchoscope used to monitor the state of the catheter tip). Preliminary stenting with metal stents was performed in 5 patients. The I-Gel lumen was wide enough to manipulate a flexible endoscope, a catheter guide was inserted for jet ventilation, and then the catheter itself was placed. The use of high-frequency ventilation mask it advisable to ensure adequate gas exchange at all stages of the surgery. Sedation with dexmedetomidine reduced the patient’s discomfort after the surgery due to the fixation of the patient’s head with stitches in a “nodding” position, which reduced anastomosis tension. In all 12 patients, this anesthesia strategy was successful and provided a more favorable environment for surgeons compared to the classical approach with the use of an endotracheal tube. In all patients, anastomosis healed by primary tension with no complications.Conclusion. The use of a supraglottic airway device, dexmedetomidine, and temporary stenting of the stenotic part of the trachea allow the surgeon to avoid tracheal intubation during circular resection and expand the range of anesthesiological tools during tracheal surgery.

Tracheal stents can be used to quickly reconstruct the airway and relieve symptoms of dyspnea in patients with tracheal stenosis. However, existing tracheal stents lead to complications such as granulation tissue formation, difficulty in removal, persistent growth of malignant tumors, stent migration, and mucus plugging. In this article, we reviewed the main methods used to reduce complications associated with tracheal stent design. Drug-eluting stents can inhibit granulation tissue formation and prevent infection and local chemotherapy. The biodegradable stent can support the trachea for some time, maintain tracheal patency, and degrade gradually, which avoids removing or replacing the stent. Radioactive stents loaded with I 125 have good potential for inhibiting the persistent growth of malignant tumors. Three-dimensional printing technology enables the manufacturing of patient-specific stents, which increases the degree of matching between the complex tracheal anatomy and the stent, thus providing a new solution for stent migration caused by structural mismatch. Minimizing the barrier of the stent to mucociliary clearance, providing an anti-fouling coating, and culturing respiratory epithelial cells on the surface of the stent are the main methods used to reduce mucus plugging. We also proposed future research directions for tracheal stents to guide the design and manufacture of ideal tracheal stents., Competing Interests: The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (© 2024 The Authors.)

Background: Due to the low incidence of malignant tracheoesophageal fistula and the paucity of relevant clinical studies, the benefits of stent implantation have not been well documented. It remains unclear which factors may affect fistula closure., Methods: Between January 2015 and January 2021, 344 patients who were diagnosed with malignant tracheoesophageal fistula at Zhongda Hospital, Southeast University, were retrospectively enrolled. Demographic and clinical data were collected. Risk factors for fistula closure identified by univariate analysis were further analyzed using multivariable logistic regression., Results: A total of 288 patients were analyzed in this study, of which 94 were treated conservatively, 170 were treated with an esophageal stent, and 24 were treated with a tracheal stent. Among them, the delta Karnofsky's performance status score values (after 2 weeks/before treatment [p = 0.0028], after 1 month/before treatment [p = 0.0103]) were significantly different between conservative and stent treatment. There was a significant reduction of pneumonia incidence in the stenting group (33.53%) compared to the conservative treatment group (77.05%) after one month (p <0.0001). In addition, the closure of fistulas was influenced by four independent risk factors: 1) treatment methods (p < 0.0001), 2) fistula size (p = 0.0003), 3) preoperative white blood cell count (p = 0.0042), and 4) preoperative Karnofsky's performance status score (p = 0.0001)., Conclusions: Stent implantation has become an effective method for treating malignant tracheoesophageal fistula compared to conservative treatment. Additionally, stent implantation, smaller fistula size, lower preoperative white blood cell count, and higher preoperative Karnofsky's performance status score suggest a better outcome., Competing Interests: The authors declare that the research was conducted in the absence of any commercial or financial relationships that could be construed as a potential conflict of interest., (Copyright © 2024 Wang, Duan, Liu and Shi.)

Airway stenting has become integral to the therapeutic endoscopic management of benign and malignant obstructive airway diseases. Despite the increased use of stents, the absence of clear guidelines for surveillance and maintenance poses the potential for unique stent-associated complications. Our case reports a rare incident of tracheal stent dislodgement, leading to its ingestion and unexpected discovery within the stomach. This case serves the purpose of shedding light on a rare yet potentially life-threatening complication and discussing types of stent and characteristics to enhance gastroenterologists' understanding of stent-related challenges and equips them to anticipate and strategize the appropriate course of action., (© 2024 The Author(s). Published by Wolters Kluwer Health, Inc. on behalf of The American College of Gastroenterology.)

Objectives: Neo-oesophageal-airway fistula (NEAF) between gastric conduit and airway is a rare but life-threatening complication of oesophagectomy for oesophageal cancer. Optimal treatment remains unknown. A meta-analysis of good-quality case series may help determine whether nonoperative management (NOM) only, upfront surgery (S), or NOM followed by surgery is associated with better 1-year post-treatment mortality, resumption of oral diet and fistula recurrence., Methods: We systematically searched PubMed, EMBASE and Web of Science for publications in English reporting case series of management and survival in patients with NEAF. Of the 177 identified studies, 62 were duplicates and 95 were not relevant to our topic. Three studies were excluded after a full-text review, due to absence of reporting of 1-year survival. Exclusion criteria to identified publications were: abstract only, malignant NEAF, absence of oesophagectomy and esogastric anastomosis, fewer than 5 patients and NEAF not the main focus of the study. Data-extraction was conducted in accordance with MOOSE guidelines. Data were pooled using random-effects model., Results: Seventeen studies (302 patients) were included. One-year post-treatment mortality was considerably lower with NOM followed by surgery [33%; 95% confidence interval (CI), 0.17-0.48] than with NOM (68%; 95% CI, 0.39-0.97) or S (67%; 95% CI, 0.36-0.98). Fistula location was not associated with 1-year mortality. Neither resumption of an oral diet nor fistula recurrence differed significantly across treatment strategies., Conclusions: NOM to prepare patients for surgery followed by surgical repair may provide the highest 1-year survival of patients with NEAF. However, patient selection criteria to each of 3 treatment strategies may have affected our findings., (© The Author(s) 2024. Published by Oxford University Press on behalf of the European Association for Cardio-Thoracic Surgery.)

The ability to engineer custom‐made medical devices and to implant them minimally invasively are two important trends in modern surgery. The personalization of the device is achieved by 3D printing it, while the capacity to deploy it minimally invasively harnesses the shape memory behavior displayed by the inks used. This study introduces a 3D printed, shape memory‐displaying tracheal stent based on novel, flexible photo‐polymerizable inks comprising polypropylene glycol/polycaprolactone triblocks. This research introduces the in situ welding strategy, whereby thin and flexible layers of the stent are separately printed, sequentially deployed, and then welded together at the tracheal site. By doing so, the insertion profile of the device is dramatically reduced and its flexibility largely increased. Porous stents are 3D printed seeking to prevent mucus plugging. By combining more than one ink, their properties are further fine‐tuned. Polyethylene glycol chains are covalently bonded to the stent surface to minimize biofilm formation, an important drawback of current tracheal stents. The in vitro cell viability and cell adhesion behavior of the treated surfaces reveal their compatibility and anti‐adhesive behavior. In order to prevent implant‐related infections, ciprofloxacin is added to the ink, and released in vitro over time, rendering the stent with antibacterial activity. [ABSTRACT FROM AUTHOR]

Blunt tracheal injury is a rare but life-threatening condition. Several indications for treatment have been reported. Conservative treatment (i.e., stenting) can be performed when the patient is clinically stable or has medical contraindications to surgical treatment. Although some studies have reported the use of tracheal stents as treatment for iatrogenic injury and blunt trauma, the efficacy of these stents is unknown. Herein, we report a case of emergency tracheoplasty for the management of tracheal stent prolapse in a patient with blunt tracheobronchial trauma. This report highlights the necessity of being cautious about the migration and prolapse of tracheal stents, which can more frequently occur in blunt trauma than in malignant stenosis or iatrogenic injury. Due to the limitations of non-surgical treatments, early surgical intervention may be lifesaving. [ABSTRACT FROM AUTHOR]

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.

Objectives: To determine if mycophenolate mofetil reduces the incidence and severity of granulation tissue in-growth in canine tracheal stent patients.Study design: Randomized clinical trial.Animals: 111 dogs from the hospital population.Methods: Client-owned dogs that received an endoluminal self-expanding tracheal stent for canine tracheal collapse between 2014 and 2020 were randomly assigned into one of two treatment groups. Control group medication protocol consisted of prednisone 0.5 mg/kg PO BID/SID/EOD × 30 days, hydrocodone 0.25 mg/kg PO TID × 30 days, and cefovecin 8 mg/kg SQ post-placement. Mycophenolate group medication protocol was identical to the control group medication protocol with the addition of mycophenolate mofetil 10 mg/kg PO BID × 30 days, SID for life. Recheck tracheoscopy was performed at 1, 3, and 6 months post-stent placement. Presence and severity of granulation tissue were determined by tracheoscopy and were recorded as a percentage of tracheal lumen obstruction by blinded evaluators (none present, 25–50%, and >50%).Results: At none of the three time points was there a statistically significant difference in grade between controls and those receiving mycophenolate (p = 0.467, p = 0.330, and p = 0.410).Conclusions and Clinical Significance: Our results suggest that mycophenolate can be safely given to these patients but do not support that its administration will reduce the incidence and severity of granulation tissue. Although a difference was observed in the severity of granulation tissue between the two groups, loss to follow-up may have influenced conclusions. A larger study would be warranted to further evaluate the effect of mycophenolate on the development of granulation tissue.

Abstract Background Intermediate bronchial fistula formation caused by mediastinal drainage tube compression and fungal infection is rare. Case presentation A 50-year-old male patient with type 2 diabetes was observed air filling in mediastinal drainage tube, 12 days after esophagectomy for esophageal squamous carcinoma. Based on the results of computed tomography, bronchoscopy and pathology, the diagnosis of intermediate bronchial fistula caused by mediastinal drainage tube compression and fungal infection was made. Anti-fungal drug and temporary covered metallic stent was used. After stent removed, the fistula was healed with some granulation hyperplasia. He was free from respiratory symptom during 1 year follow-up. Conclusion Intermediate bronchial fistula caused by the combination of mediastinal drainage tube compression and fungal infection is rare. Timely stenting could boost the healing of fistula via granulation tissue proliferation.

Esophagobronchial and esophagotracheal fistulas are rare but complex diseases with a heterogeneous spectrum of underlying etiologies. Common causes are locally advanced tumors of the esophagus and larynx, traumatic perforation from the esophageal or tracheal side as well as postoperative fistulas. The management of esophagotracheal and esophagobronchial fistulas always involves different health care providers and in most cases patients require a multidisciplinary treatment on the intensive care unit. The therapeutic concept primarily depends on the underlying cause, localization and size of the fistula but decision making is also influenced by the severity of the course of sepsis and the extent of the respiratory dysfunction. Endoscopic management with esophageal and/or tracheobronchial stenting is the most common treatment. Surgical reconstructive procedures are predominantly reserved for patients with a treatment refractory fistula or a septic multiple organ failure. The prognosis is particularly influenced by the underlying disease. [ABSTRACT FROM AUTHOR]

Objective: Develop a prototype steroid eluting stent suitable for endoscopic treatment of subglottic stenosis. Methods: Rectangular-shaped spoke design stents thermally molded into horseshoe-shaped stents were developed using AutoCAD program, and printed on a Lulzbot 3D printer with polycaprolactone (PCL). Kenalog saturated AEROSIL 200 was embedded in the PCL filament. Horizontal radial force measurements were measured at baseline, 1 day, and 1 month when deformation switched from bending to compression. Amount of Kenalog eluted after 1 day, 1 week and 1 month were measured using HPLC. Results: Horizontal pressure applied to the PCL stent corresponding to a 5–0 ET were 1.27 ± 0.38 lb. at baseline, 1.79 ± 0.045 lb. at 1 day, 1.94 ± − 0.22 lb. at 1 week and 2.07 ± 0.11 lb. at 1 month. The horizontal pressure applied to PCL stent corresponding to an 8–0 ET tube were 0.82 ± 0.018 lb. at baseline, 1.008 ± 0.045 lb. at 1 day, 0.95 ± − 0.064 lb. at 1 week and 1.078 ± 0.021 lb. at 1 month. The amount of Kenalog eluted increased from 5.78 µg/mL at 1 day to 15.01 µg/mL at 1 week to 19.35 µg/mL at 1 month. Conclusion: This proof-of-concept project is an initial step to demonstrate and create a novel stent in the treatment of subglottic stenosis that applies expansile force on the trachea, elutes steroids and dissolves. Over time the expansile force along the trachea increases allowing the PCL to mucosalize, while it dissolves and continues to elute steroids. The limitations of this in vitro study necessitate experiments on animal models, such as rabbit tracheas to observe for complications and histologic changes. Level of evidence: This proof-of-concept project is a Level 5 mechanism-based reasoning study. [ABSTRACT FROM AUTHOR]

Esophageal cancer is the most common cause of extrapulmonary malignant central airway obstruction (MCAO). MCAO is usually managed by a multidisciplinary approach involving tumor debulking, stent placement, and palliative radiotherapy. MCAO is a challenge in itself; here, it becomes even more challenging as it was accompanied by grade 3 oral submucous fibrosis, nasal synechiae, and multiple enlarged cervical nodes causing excessive compression of the trachea along with acute hypercapnic respiratory failure. Herein, a 65-year-old woman with multiple challenges, where death was imminent, managed with a collaborative approach involving awake nasal intubation in the sitting position and placement of a stent via a flexible bronchoscope, as rigid bronchoscopy was not possible in view of limited mouth opening. Overcoming these challenges led to completing the procedure successfully and palliating the symptoms. [ABSTRACT FROM AUTHOR]

Background: 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., Methods: 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., Results: 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)., Conclusions: 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., Competing Interests: Conflicts of Interest: All authors have completed the ICMJE uniform disclosure form (available at https://jtd.amegroups.com/article/view/10.21037/jtd-23-738/coif). The authors have no conflicts of interest to declare., (2024 Journal of Thoracic Disease. All rights reserved.)

Abstract Background Stent migration is a common complication in treating trachea stenosis. There is no report concerning suture fixation of tracheal stent. The aim of this study was to investigate whether suture fixation of tracheal stent could avoid stent migration in patients with upper trachea stenosis. The complications were further investigated. Methods The patients with upper trachea stenosis who underwent tracheal stent placement for benign/malignant conditions in our hospital between May 2016 and April 2018 were retrospectively reviewed. Clinical data were collected for each patient, including age, gender, co-morbid diseases, site of tracheal obstruction, degree of tracheal obstruction, success of stent placement, impact on patient’s symptoms, complications, etc. Results Eleven patients (8 males and 3 females; range of age: 17–85, and average age of 63) were enrolled into this study. Six silicone stents and five membrane-covered metal stents were used. The surgery was successfully performed in all the cases. The postoperative recovery was uneventful. All symptoms of the patients were relieved. No complications occurred. The average follow-up for patients was 5 months (range of 1–13 months). During the follow-up, no stent migration was observed according to CT and bronchoscope. Conclusion The results suggested that suture fixation of stents could avoid stent migration in treating upper trachea stenosis with metal stent or silicone stent. This method seemed to be effective without operation complications.

The high-order nonlinear terms are applied to express the strain–stress curves of shape memory alloy (SMA) materials, and a new type of SMA model is proposed. Cough process is regarded as a strong stochastic process, and the mechanical model of an SMA tracheal stent in cough process is proposed where the large deformation caused by cough is considered. The system's natural frequency is obtained, and its dynamic response is analyzed. The analysis and simulation results show that when the intensity of outside excitation increased 3.5 times (from 0.2 to 0.7), the system's first-passage time was advanced by 19%, which means that the increase of the cough intensity will cause the loss of the stent; the large-amplitude vibration can be eliminated by selecting materials with appropriate parameters, which means the loss of tracheal stent can be avoided even in strong cough. This paper provides a new way to avoid the stent's loss. [ABSTRACT FROM AUTHOR]

Background: Dogs with tracheal stents often have positive airway bacterial cultures. The pathogenicity of these organisms and risk factors for infection have not been investigated. Objective: Describe bacterial infection in dogs with tracheal collapse before and after tracheal stent placement. Animals: Fifty‐three client‐owned dogs. Methods: Retrospective review of medical records of dogs receiving tracheal stents with thoracic radiographs, tracheoscopy, and endotracheal lavage. Results: There was no difference between the overall prevalence of dogs with positive bacterial cultures before (31/38; 82%) or after stent placement (24/31; 77%) (P =.67). An increased number of geriatric (17/28; 61%) and traditional‐type collapse (TTC) (16/26; 62%) dogs had positive pathogenic airway infections before stent placement, compared to young (8/25; 32%; P =.04) and malformation‐type collapse (MTC) dogs (9/27; 33%; P =.04). After tracheal stent placement, geriatric dogs had a 52% reduction in pathogenic bacteria infection frequency (P =.02) and dogs with TTC had a 56% reduction in pathogenic bacteria infection frequency (P =.01). Significant risk factors for pathogenic infection included a history of pneumonia (OR = 3.6; 95% CI, 0.28‐43.36) and cardiac disease (OR = 1.25; 95% CI, 0.16‐9.92) in geriatric dogs, and hepatomegaly in young dogs (OR = 1.5; 95% CI, 0.12‐19.44). Conclusions and Clinical Importance: Tracheal stent placement does not increase the overall rate of pathogenic bacterial infection in dogs with tracheal collapse and can decrease the rate of subsequent pathogenic infections in geriatric dogs and dogs with TTC that require tracheal stenting. Airway culture and cytology should be performed in all dogs undergoing tracheal stent placement. [ABSTRACT FROM AUTHOR]

Abstract Tracheoesophageal fistulas (TEF) present a perioperative management challenge. A 62 year-old man with esophageal carcinoma presented with a large tracheoesophageal fistula extending most of the trachea. Previously, the patient had two overlapping esophageal and one tracheal stent placed, but he developed progressive tracheal disruption due to esophageal stent perforation near the level of the cricoid. This case describes the anesthetic management of tracheal stent placement for an expanding TEF. Management included a spontaneous breathing inhalation induction followed by ventilation through a supraglottic device—laryngeal mask airway (LMA). Finally, during rigid bronchoscopy, a combination of bag ventilation and jet ventilation was utilized.

Abstract Background The majority of adult primary tracheal tumors are malignant; however, as one type of benign tumors, lipoma is extremely uncommon. Case Description We report a case where lipoma was first misdiagnosed as bronchial asthma, followed by sudden aggravation of dyspnea after trauma, and computed tomography (CT) examination of the neck and chest confirmed a tracheal tumor. Through multiple bronchoscopy interventions and placements of a tracheal stent, little therapeutic benefit was discovered, and resection of the tracheal tumor combined with tracheal end-to-end anastomosis was performed to ultimately achieve a cure. Conclusion Primary tracheal tumors should be highly suspected in patients with recurrent and gradually worsening dyspnea; timely cervical, thoracic CT and bronchoscopy can provide an accurate diagnosis. Surgical radical resection is the only way to cure all benign tracheal tumors such as lipoma.

Endoscopic approach with recanalization and stenting is one of the methods for cicatricial tracheal stenosis. Major complications may occur if service life of stents is not observed. However, there are currently no clear timing for stenting. In world practice, there are no indications on lifelong stenting for cicatricial tracheal stenosis. Restenosis is more common after stent removal and requires repeated stenting or another treatment. In case of prolonged stenting, silicone stent should be periodically replaced with a similar one due to destruction of silicone rubber. As a rule, this maneuver is necessary after 1-3 years. Currently, there is no information about maximum allowable duration of stent without replacement and possible complications. Condition of trachea after prolonged stenting is also unknown. We present long-term (27 years) tracheal stenting with a silicone stent. Stent fragmentation and dislocation throughout this period led to respiratory failure and emergency removal. Tracheal lumen was satisfactory immediately after procedure. However, restenosis appeared after 1.5 months and required endoscopic dilation with discussion of appropriate treatment option. However, the patient refused tracheal resection with anastomosis and underwent repeated stenting with similar stent and favorable immediate result.

The oxygen reserve index (ORi™) is a new noninvasive and continuous variable, which represents a moderate hyperoxygenation status, with a unitless scale between 0.00 and 1.00. When percutaneous oxygen saturation (SpO2) exceeds 100%, arterial blood oxygen partial pressure cannot be evaluated without performing arterial blood gas analysis. Because of significant air leakage during rigid bronchoscopy, it is difficult to monitor respiration using capnography, which does not measure end-tidal carbon dioxide (ETCO2) accurately. A 66-year-old man (175 cm, 76.8 kg) with a chief complaint of difficulty in breathing was diagnosed with a thyroid tumor. Computed tomography revealed tracheal stenosis due to direct invasion of the thyroid tumor; therefore, tracheal stenting was planned immediately. After supplying 6 L/min oxygen with a face mask and administering 180 mg of propofol intravenously, the supraglottic airway was intubated. General anesthesia (total intravenous anesthesia) through continuous administration of 6-10 mg/kg/h of propofol and intermittent administration of 50 µg of fentanyl (total 200 µg) preserved spontaneous breathing. During tracheal stent insertion, disconnection between the oxygen supply system and rigid bronchoscopy, and tracheal stent expansion, the ORi tended to decrease before SpO2 decreased. Thus, measuring ORi could prevent hypoxemia during tracheal stent insertion using rigid bronchoscopy. [ABSTRACT FROM AUTHOR]

A tracheoesophageal fistula (TEF) is a pathological connection between the trachea and esophagus. Infectious diseases rarely lead to TEF, and tuberculosis is the most common cause of TEF among all infectious causes. A 78-year-old male patient under examination for esophageal malignancy at the gastroenterology service, and who was expected to undergo an endoscopic biopsy, was diagnosed with aspiration pneumonia after complaints of dyspnea and coughing after liquid intake, and was transferred to chest diseases clinic. TEF was identified from a bronchoscopy. Mycobacterium tuberculosis DNA was isolated during a bronchial aspiration. An endoscopic biopsy, performed after esophageal malignancy was suspected, gave the result of a granulomatous reaction. The patient was diagnosed with tuberculosisinduced TEF. Anti-tuberculosis treatment was initiated, and a tracheal Y stent was fitted. In this article we present a rare case in which a TEF emerged secondary to tuberculosis, and suggest that tuberculosis may be a cause of TEF. It is advised that before starting invasive surgical TEF treatment, it is essential to take the necessary precautions. [ABSTRACT FROM AUTHOR]

In this study, we report the production and characterization of tracheal stents composed of polydimethylsiloxane/nanostructured calcium phosphate composites obtained by reactive synthesis. Tracheal stents were produced by transfer molding, and in vivo tests were carried out. PDMS was combined with H3PO4 and Ca(OH)2 via an in situ reaction to obtain nanoparticles of calcium phosphate dispersed within the polymeric matrix. The incorporation of bioactive inorganic substances, such as calcium phosphates, improved biological properties, and the in situ reaction allowed tight coupling of particles to the matrix. Results showed the presence of the nanoparticles of DCPA and CDHA. The porosity generated during mixing decreased the tensile strength and tear properties. Composites presented higher values of cell viability compared with those for PDMS. In vivo tests indicated the presence of inflammatory tissue 30 days after implantation in both cases. Thus, the present biomaterial shows potential for application in tracheal disease, however further evaluation is needed. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater, 2018. © 2018 Wiley Periodicals, Inc. J Biomed Mater Res Part B: Appl Biomater 107B: 545–553, 2019. [ABSTRACT FROM AUTHOR]

Objective: To evaluate outcomes of surgical repair of postesophagectomy neoesophagus-airway fistulas (NEAFs)., Methods: We retrospectively included consecutive patients with NEAF managed by various techniques at our center between August 2009 and July 2021., Result: Of the 11 patients (median age, 60 years; interquartile range, 58, 62), 4 had received induction chemoradiotherapy and 4 others induction chemotherapy. NEAF was mainly a complication of anastomotic leakage (n = 6) or attempted stenosis treatment (n = 3). The airway mainly involved was the trachea (n = 8). Airway defects were repaired by resection-anastomosis (n = 5), perforator flaps (n = 4), pedicled pericardium (n = 1), and/or direct suturing (n = 2). Gastric conduit defects were repaired by perforator flaps (n = 6), direct suturing (n = 2), or pedicled pericardium (n = 1). Of the 7 perforator flaps, 4 were internal mammary-artery, two dorsal intercostal-artery, and one supraclavicular-artery flaps. After a median follow-up of 100 months, 2 patients died on early postoperative course from NEAF repair failure and 3 from late NEAF recurrence at 4, 11, and 33 months. Among the remaining 6 patients, 1 died from local tumoral recurrence at 13 months, 1 was last on follow-up at 27 months, alive and eating normally. The other 4 were free from NEAF recurrence and dysphagia or swallowing disorder at 50 months' follow-up. These 4 results were obtained thanks to perforator flap interposition and airway resection anastomosis., Conclusions: Surgical NEAF repair using perforator flap interposition may provide satisfactory long-term function after strong prehabilitation., Competing Interests: The authors reported no conflicts of interest. The Journal policy requires editors and reviewers to disclose conflicts of interest and to decline handling or reviewing manuscripts for which they may have a conflict of interest. The editors and reviewers of this article have no conflicts of interest., (© 2023 The Author(s).)

The paper designed a bionic woven tracheal stent and the stent was a multi-layer tubular structure with a transverse pipeline. Polydioxanone (PDO) monofilament and β-hydroxybutyrate and β-hydroxyvalerate copolymers/polylactic (PHBV/PLA) multifilament were chosen as the tissue engineering tracheal stent materials, and chitosan was chosen as the coating material. This study selected appropriate basic fabric structures and prepared the tracheal stent by setting reasonable weaving parameters, then treated the sample with coating and heat setting. Radical compression performances of the horizontal pipeline and longitudinal pipeline of this tracheal stent were investigated, and the experimental results showed that the stent had good performance on radial supporting force and elastic recovery, which meant it could supply adequate supports for cell growth and tissue regeneration of tracheal lesions; the horizontal pipeline could provide a good experimental foundation for reconstruction of the cartilage ring. [ABSTRACT FROM AUTHOR]