Complications of Tracheobronchial Airway Stents

Endobronchial Suture of Tracheoesophageal Fistula Through Rigid Bronchoscopy Without Tracheostomy: A Preliminary, Observational Retrospective Study

Background: A tracheoesophageal fistula (TEF) represents a condition characterized by abnormal communication between the gastrointestinal tract and the airways. Although the current gold-standard treatment is surgery, pre-existing clinical conditions may represent contraindications. We therefore propose a bronchoscopic approach through rigid bronchoscopy without tracheostomy for total repair in patients suffering from benign tracheoesophageal fistulas. Methods: Fistula suture through rigid bronchoscopy with either absorbable (Vycryl 3.0, Ethicon, Inc.) or non-absorbable (Prolene, Ethicon US, LLC. 2022.) sutures was performed using a long needle holder as an alternative resolutive procedure to surgery. From 2015 to 2022, we retrospectively reviewed 10 consecutive patients affected by TEFs in our Endoscopic Unit at San Camillo-Forlanini Hospital (Rome, Italy) who underwent this bronchoscopic procedure. The coprimary outcomes were the proportion of fistulas successfully treated with the innovative treatment proposed and the rate of procedure-related complications. Results: The complete healing of the fistula was achieved in nine of the ten patients after 1 year. Follow-up with flexible bronchoscopy was scheduled and carried out at 1, 3, and 12 months following rigid bronchoscopy. Overall, seventeen endoscopic repair procedures were performed. Five of these patients required more than one endoscopic treatment to reach complete fistula closure. Fistula closure was not achieved post-procedure in one patient. No complications during procedures or in the follow-up period were reported. Conclusions: Despite the small cohort, our preliminary study has demonstrated that the endoscopic approach through rigid bronchoscopy, without tracheostomy, represents a safe and satisfactory alternative for patients affected by TEFs who are not suitable for surgery.

Degradation and Fatigue Behavior of 3D-Printed Bioresorbable Tracheal Splints

Severe infantile tracheobronchomalacia (TBM) is often treated with invasive surgery and fixed-size implants to support the trachea during respiration. A novel 3D-printed extra-luminal splint has been developed as a flexible and bioresorbable alternative. Therefore, the goal of the present study was to use an in vitro breathing simulator model to comprehensively evaluate the structural stiffness and failure modes of two sizes of a novel bioresorbable 3D-printed splint design under a range of physiological degradation conditions. Two thicknesses, 2 mm and 3 mm, of a novel 3D-printed bioresorbable splint were evaluated under two different degradation conditions, phosphate-buffered saline (PBS) and sodium hydroxide (NaOH). The splints were subjected to simulated breathing loading, involving a cyclic opening and closing of the splint by 2 mm, for a targeted duration of 7.5 to 30 million cycles. A separate new set of splints were statically soaked in their respective degradation condition for a comparative analysis of the effects of cyclic loading by the degradation medium. After successfully simulated breathing or static soaking, non-destructive tensile and compressive strengths were evaluated, and overall stiffness was calculated from destructive tensile testing. The present study indicates that the splints were more significantly degraded under simulated breathing conditions than under soaking. Cyclic simulated breathing specimens failed far earlier than the intended duration of loading. Over time, both 2 mm and 3 mm splints became increasingly more flexible when subjected to the static degradation conditions. Interestingly, there was little difference in the compressive and tensile strengths of the 2 mm and 3 mm thickness splints. The bioresorbable nature of PCL offers a valuable advantage as it eliminates the need for splint removal surgery and increases device flexibility over time with degradation. This increased flexibility is crucial because it allows for uninhibited growth and development of the infant's trachea over the intended use period of 2 years. The results of this study confirm that the splints were able to withstand tensile forces to prevent tracheal collapse. This study further supports the successful use of 3D-printed splints in the treatment of infantile TBM.

Subcutaneous fixation model for complex stenting of recurrent laryngotracheal stenosis

BACKGROUND

A straight silicone stent can be used to treat proximal benign tracheal stenosis in non-surgical candidates. However, stent migration is a common complication when placed at a particular location and can lead to major complications. This case series of laryngotracheal stenosis reports a fixation method for straight silicone stents in the subglottic trachea (Stage 3 of the McCaffrey classification).

METHODS

The medical charts of these patients scheduled for straight silicone stent placement with suture fixation between 2014 and 2020 at the CHU UCL Namur Hospital (Belgium) were retrospectively reviewed. The procedure was performed using a rigid bronchoscope. Details of the procedure were obtained from medical records.

RESULTS

This case series included six patients (males: 4, females: 2). The median patient age was 59 years. Two suture fixations were placed following previous silicone stent migration episodes, whereas the others were placed proactively to avoid this risk. All fixations were performed by the device Freka® Pexact II ENFIt®, originally developed for gastropexy in endoscopic gastrostomy. The sutures were subcutaneously buried.

CONCLUSIONS

During the 6-month follow-up period, complications such as fixation issues and stent migration were reported despite the off-label use of the treatment. The straight silicone stent fixation technique used in this case series was simple and effective for securing the stent in upper benign tracheal stenosis.

Graphene oxide-loaded rapamycin coating on airway stents inhibits stent-related granulation tissue hyperplasia

OBJECTIVES

Our objective was to explore the safety and efficacy of a graphene oxide-loaded rapamycin-coated self-expandable metallic airway stent (GO@RAPA-SEMS) in a rabbit model.

METHODS

The dip coating method was used to develop a GO@RAPA-SEMS and a poly(lactic-co-glycolic)-acid loaded rapamycin-coated self-expandable metallic airway stent (PLGA@RAPA-SEMS). The surface structure was evaluated using a scanning electronic microscope. The in vitro drug-release profiles of the 2 stents were explored and compared. In the animal study, a total of 45 rabbits were randomly divided into 3 groups and underwent 3 kinds of stent placements. Computed tomography was performed to evaluate the degree of stenosis at 1, 2 and 3 months after the stent operation. Five rabbits in each group were sacrificed after the computed tomography scan. The stented trachea and blood were collected for further pathological analysis and laboratory testing.

RESULTS

The in vitro drug-release study revealed that GO@RAPA-SEMS exhibited a sudden release on the first day and maintained a certain release rate on the 14th day. The PLGA@RAPA-SEMS exhibited a longer sustained release time. All 45 rabbits underwent successful stent placement. Pathological results indicated that the granulation tissue thickness in the GO@RAPA-SEMS group was less than that in the PLGA@RAPA-SEMS group. The TUNEL and hypoxia-inducible factor-1α staining results support the fact that the granulation inhibition effect in the GO@RAPA-SEMS group was greater than that in the PLGA@RAPA-SEMS group.

CONCLUSIONS

GO@RAPA-SEMS effectively inhibited stent-related granulation tissue hyperplasia.

The "Hitch-Stitch" for Preventing High Tracheal Stent Migration: Expanding Indications and Extended Experience

BACKGROUND

Airway stenting is a standard treatment option for tracheo-bronchial obstruction and other conditions like tracheo-esophageal fistula (TEF).

METHODS

To prevent stent migration, a percutaneous fixation strategy called the "hitch-stitch" was described in 2016 as an efficient technique. We describe an extended experience of the "hitch-stitch" for silicone stents in high tracheal stenting situations and expanding indications to metal stents.

RESULTS

Seventy-four percutaneous stitches were placed in 54 patients (36 males and 18 females). The mean age of the patients was 42 (±19) years. The indication for stenting was tracheal stenosis in 63/74 (85%) cases and TEF in 11/74 (15%) cases. Silicone stents were used in 56/74 (75.5%) cases while self-expanding metal stents (SEMS) were used in 18/74 (24.5%) cases. The majority of the stents (62/74, 85%) were high tracheal stents. The "hitch-stitch" as an anti-migration strategy had a high success rate, with distal stent migration in only 2 cases (2.7%) as the stitch had given way-these were repositioned and hitched with double stitches. Minor complications included delayed skin healing (2.8%) and suture site infection (1.4%), which was successfully managed with oral antibiotics. Stitch removal was easy with no complications.

CONCLUSION

In this large series of percutaneous "hitch-stitch" as a stent migration prevention strategy, long-term data shows it is safe and effective in an expanded cohort of silicone stents. Its extended utility is the successful application to metal stents, especially in TEF, where the consequences can be deleterious. It is simple to do, with minimal extra requirements and not associated with any significant complications.

Clinical Factors for Successful Removal of Airway Silicone Stents in Patients With Post-Tuberculosis Tracheobronchial Stenosis

BACKGROUND

After relieving stenosis with an airway silicone stent in post-tuberculosis bronchial stenosis (PTTS), stent removal is attempted if it is determined that airway patency can be maintained even after stent removal. However, the factors affecting airway stent removal are not well known. We investigate the factors that enable the successful removal of airway silicone stents in patients with PTTS.

METHODS

We retrospectively analyzed PTTS patients who underwent bronchoscopic intervention from January 2004 to December 2019. Successful stent removal is defined as airway patency maintained when the stent is removed, so that reinsertion of the stent is not required. A multivariate logistic regression analysis was used to identify independent factors associated with successful stent removal at the first attempt.

RESULTS

Total 344 patients were analyzed. Patients were followed up for a median of 47.9 (26.9-85.2) months after airway stent insertion. Approximately 69% of PTTS patients finally maintained airway patency after the stent was removed. Factors related to successful stent removal at the first attempt were older age and male sex. Absence of parenchymal calcification, segmental consolidation & bronchiolitis, and no trachea involved lesion were relevant to the successful stent removal. Stent dwelling for 12-24 months was associated with successful stent removal compared to a duration of less than 12 months.

CONCLUSION

For patients whose airway patency is determined to be maintained even without a stent, it is necessary to attempt stent removal in consideration of factors related to successful stent removal.

Rigid Bronchoscopy for Post-tuberculosis Tracheobronchial Stenosis

The healing process of tracheobronchial tuberculosis (TB) results in tracheobronchial fibrosis causing airway stenosis in 11% to 42% of patients. In Korea, where pulmonary TB is still prevalent, post-TB tracheobronchial stenosis (PTTS) is one of the main causes of benign airway stenosis causing progressive dyspnea, hypoxemia, and often life-threatening respiratory insufficiency. The development of rigid bronchoscopy replaced surgical management 30 years ago, and nowadays PTTS is mainly managed by bronchoscopic intervention in Korea. Similar to pulmonary TB, tracheobronchial TB is treated with combination of anti-TB medications. The indication of rigid bronchoscopy is more than American Thoracic Society (ATS) grade 3 dyspnea in PTTS patients. First, the narrowed airway is dilated by multiple techniques including ballooning, laser resection, and bougienation under general anesthesia. Then, most of the patients need silicone stenting to maintain the patency of dilated airway; 1.5 to 2 years after indwelling, the stent could be removed, this has shown a 70% success rate. Acute complications without mortality develop in less than 10% of patients. Subgroup analysis showed successful removal of the stent was significantly associated with male sex, young age, good baseline lung function and absence of complete one lobe collapse. In conclusion, rigid bronchoscopy could be applied to PTTS patients with acceptable efficacy and tolerable safety.

Tracheal Stent Migration in a Patient With Tracheomalacia and Tracheoesophageal Fistula: A Rare Case

Tracheomalacia refers to diffuse or segmental tracheal weakness. Most commonly, tracheomalacia develops after prolonged endotracheal intubation or tracheostomy. Surgical management is warranted in symptomatic patients with severe tracheomalacia. Relief of airway obstruction via stenting often provides immediate improvement in both airflow and symptoms. However, stent placement is associated with significant complications. Here, we present the case of a 71-year-old man who was brought to the emergency department with acute respiratory distress. The patient was known to have tracheomalacia with tracheoesophageal fistula. He had multiple medical comorbidities, including longstanding hypertension, diabetes mellitus, and asthma. The patient had a progressive decline in his level of consciousness and was admitted to the intensive care unit for further management. Despite the maximum ventilatory support, the patient did not achieve an adequate oxygenation level. The patient underwent tracheal stent placement by the interventional radiology team. The insertion was unsuccessful despite three attempts. The tracheal stent had migrated into the upper esophagus on the first and second insertion attempts. Because the patient was unstable to tolerate further attempts, the multidisciplinary team recommended the insertion of an esophageal stent to cover the tracheoesophageal fistula. Despite this, the patient continued to have air leakage with progressive worsening of his respiratory condition as he developed multiorgan failure and died. The management of tracheomalacia in the setting of the tracheoesophageal fistula may pose several challenges. The present case highlights an essential complication of stent placement with the stent migrating into the tracheoesophageal fistula, which is an unusual site of migration. A multidisciplinary approach is crucial in the management of difficult cases of tracheomalacia.

Determination of patient-specific airway stent fit using novel 3D reconstruction measurement techniques: a 4-year follow-up of a patient

Managing complex benign airway disease is a major challenge in interventional pulmonology. With the introduction of additive manufacturing in the medical field, patient-specific (PS) implants are an innovate prospect for airway management. Historically, stents were oversized to resist migration. However, the optimal degree and impact of stent oversizing remains unclear. The ability to design stents based on computed tomography (CT) invites opportunity to understand sizing. Here, we report a novel three-dimensional (3D) image reconstruction tool to quantify fit repeatedly over time. Analysis of CT imaging before and after successive stent implants in a single patient with different areas of stenosis and malacia was done. Nine PS airway stents over 4 years (five left mainstem and four right mainstem) were studied. The distance between the airway model and stent was calculated. The CT images were correlated to stent designs in CloudCompare software (v2.10-alpha) for novel analysis. Heat map was exported depicting the distances between the airway and the stent to the clinician's prescribed stent model. Corresponding histograms containing distances, mean, and standard deviation were reported. It is possible to measure stent fit based on heat map quantification on patient imaging. Observation of the airway over time and stent change suggests that the airway became more open over time requiring increased stent diameters. The ability to design and measure stent fit over time can help quantify the utility and impact of PS silicone airway stent. The airway appears to display plasticity such that there is notable change in stent prescription over time.

In Vitro Evaluation of Zinc Oxide Tetrapods as a New Material Component for Glaucoma Implants

In our previous study we were able to show that zinc oxide (ZnO) tetrapods inhibit wound healing processes. Therefore, the aim of this study was to test the antiproliferative effect of two types of porous polydimethylsiloxane (PDMS)/ tetrapodal zinc oxide (ZnO-T) materials, as well as their usability for glaucoma implants. To find the best implant material, two different porous PDMS/ZnO-T materials were examined. One consisted of 3D interconnected PDMS coarse-pored foams with protruding ZnO-T particles; the other consisted of fine-pored 3D interconnected ZnO-T networks homogeneously coated by a thin PDMS film in the nanometer range. Fibroblast cell viability was investigated for both materials via MTT dye, and some implant material samples were further processed for electron microscopy. Both PDMS/ZnO-T materials showed reduced cell viability in the MTT staining. Furthermore, the electron microscopy revealed barely any fibroblasts growing on the implant materials. At the surface of the fine-pored implant material, however, fibroblasts could not be observed in the etched control samples without ZnO-T. It was found that post-processing of the material to the final stent diameter was highly challenging and that the fabrication method, therefore, had to be adapted. In conclusion, we were able to demonstrate the antiproliferative potential of the two different PDMS/ZnO-T materials. Furthermore, smaller pore size (in the range of tens of micrometers) in the implant material seems to be preferable.

Short- versus Long-term Stenting in Children with Subglottic Stenosis Undergoing Laryngotracheal Reconstruction

Objectives Suprastomal stents are routinely used in laryngotracheal reconstruction (LTR) to stabilize grafts and provide framework to sites of repair. However, the duration of stenting varies according to patient history and physician preference. We examined outcomes of short- versus long-term stenting in children with subglottic stenosis (SGS) undergoing LTR. Study Design Case series with chart review. Setting Tertiary care pediatric hospital. Subjects and Methods Thirty-six children <18 years old who underwent double-stage LTR for SGS from January 2012 to January 2015 were included. Demographic data, stenosis grade, and decannulation rates were compared between children with short-term stenting (≤21 days; n = 14) and those with long-term stenting (>21 days; n = 22). Results No significant difference between groups was seen for sex, age, race, or previous repair. Children in the short-term group were stented for 10.9 ± 4.9 days, compared with 44.0 ± 10.6 for those long-term ( P < .0001). A similar number of children with short- versus long-term stents had grade 3/4 stenosis preoperatively (71.4% vs 77.2%). Although time to decannulation was not significantly different, 72.7% of children with long-term stents were decannulated, as opposed to 35.7% with short-term stents ( P = .03). After adjusting for grade at surgery and age, children with long-term stents had 4.3 greater odds (95% CI, 1.0-18.3) of decannulation than children with short-term stents. Conclusions Children with long-term stenting were more likely to be successfully decannulated. Although long-term stenting improved outcomes for children with SGS, additional research is needed to better define ideal candidates for short- versus long-term stenting.

Removable sinus stent for endoscopic sinus surgery: An animal trial

BACKGROUND

The goal of endoscopic sinus surgery in chronic sinusitis is to create good drainage of the paranasal sinuses. Metal stents used to prevent lateralization of the middle concha are associated with adverse effects.

OBJECTIVE

The aim of this experimental study was to evaluate the feasibility and safety of a newly developed composite removable stent.

METHODS

The composite removable stent was implanted in nine sheep (18 stents) in the ethmoid cavity after performing an ethmoidectomy and was examined for stability, ease of removal, and adverse effects. Histologic findings were compared between implantation and nonimplantation sites at several time points after stent deployment and removal.

RESULTS

None of the stents migrated or fell out of the nose. After 4 weeks, there was no infection in the nose or around the stents, and there was no damage to the mucosa. An histologic study showed only mild-to-moderate inflammatory cell infiltration relative to control sites, with no damage to the mucosal epithelium and no necrosis at distant sites. At 2 weeks after stent removal, slight-to-moderate fibroplasia was noted in the deep nasal tissue, with slight-to-moderate osteocartilaginous metaplasia and bone remodeling but no necrotic or inflammatory changes in surrounding tissues. At 4 weeks after stent removal, the middle meatus remained open.

CONCLUSION

The promising results of the composite removable stent in a sheep model justify further studies in patients undergoing endoscopic sinus surgery for chromic sinusitis.

Complications of Metallic Stents in the Pediatric Airway

OBJECTIVE: Our aim was to present our experience with complications caused by placement of metallic stents in the pediatric airway.

DESIGN AND SETTING: We conducted a retrospective study of the medical records of patients with complications resulting from metallic stent placement, managed by the senior authors between 1993 and 2002.

RESULTS: Nine children had complications associated with the placement of metallic airway stents. Of these, 8 children required stent removal. Granulation tissue and tracheal stenosis were seen in all 7 children with long standing stent placement. There was 1 stent death in this series.

CONCLUSIONS: Metallic airway stents can cause significant complications in the pediatric airway. These complications may supersede the airway compromise that necessitated their initial placement. As such, metallic stent placement should be approached with caution. The likelihood and severity of complications increase with time, as do the difficulties encountered upon removal. The proportion of patients in whom metallic stents may be placed “permanently” without complications is not known. Therefore we recommend that metallic airway stents be considered a temporizing measure of limited duration.

Tracheobronchial stenting for malignant airway disease: long-term outcomes from a single-center study

The aim of this retrospective study is to investigate the immediate and long-term outcomes following the insertion of covered and uncovered self-expandable metallic stent (SEMS) for the management of malignant tracheobronchial disease. A total of 49 patients (27 male, mean age 60.9 ± 15 years) underwent 77 SEMS insertions (57 uncovered). The procedure was performed in theater using combined bronchoscopic and fluoroscopic guidance. The study's primary end points included technical success (97.9%), clinical success (91.8%), and symptom recurrence (14.2%). The mean follow-up time was 5.5 ± 5.9 months. We concluded that tracheobronchial SEMSs provide safe and effective minimally invasive long-term management of patients with symptomatic malignant airway disease.

Rigid Bronchoscopic Management of Complications Related to Endobronchial Stents after Lung Transplantation

Objectives:

We reviewed the utility of rigid bronchoscopy in the management of complications resulting from placement of metallic endobronchial stents after lung transplantation.

Methods:

A retrospective review was performed of all lung transplant patients who required metallic endobronchial stenting between 2005 and 2009. The patients' medical records were reviewed, and details regarding stent placement, complications, and removal were recorded.

Results:

A total of 43 metallic stents were placed in 22 patients who had unilateral or bilateral lung transplantation. Stent complications occurred in 18 cases (42%) at a mean of 285 days after placement and included stent collapse, stent breakdown, stent migration, ingrowth of granulation tissue, and coughing up of fractured pieces of stent. Of the 43 stents placed, only 4 (9%) had to be removed. Removal was readily accomplished by rigid bronchoscopic techniques, even when some endothelial ingrowth had occurred.

Conclusions:

Lung transplantation presents unique challenges in airway management. Endobronchial stenting plays an important role in the management of anastomotic stenosis and bronchomalacia in these patients. Although metallic stents have significant advantages, complications often arise that occasionally necessitate their removal. Rigid bronchoscopy is a valuable tool in the management of endobronchial stent complications after lung transplantation.

Endotracheal Nitinol Stents

Objective

To reflect on lessons learned placing endotracheal nitinol stents in children.

Study Design

Case series with chart review.

Setting

Tertiary care children’s hospital.

Subjects and Methods

All children who underwent nitinol cervical tracheal stenting were included. Records were carefully reviewed for intraoperative and postoperative complications, management choices, outcomes, and factors that influenced results.

Results

Between 1999 and 2011, 7 children underwent 13 stent placements. Median follow-up was 5 years (range, 1-12 years). Six patients underwent stenting as a salvage procedure following open attempts at airway reconstruction. Four patients remain decannulated with their stent in place (median follow-up 7 years). The fifth patient had his stent removed endoscopically after 50 days because it became apparent that his obstruction was primarily laryngeal. The sixth child had his stent removed via a tracheal fissure after 14 months because of recalcitrant subglottic inflammation at the superior stent border. The seventh patient was decannulated for over 2 years but ultimately required tracheotomy replacement because of stenosis with the stent lumen. Complications included stent migration (23%), restenosis (29%), edema (29%), and granulation (57%).

Conclusion

Endotracheal nitinol stents provide a realistic opportunity for decannulation in children for whom other options have failed but should be reserved only as a salvage procedure in severely complicated airways. Our experience has taught valuable lessons about stent indications, sizing, characteristics, and deployment, as well as means to avoid and manage their complications.

Expandable tracheal stenting for benign disease: worth the complications?

OBJECTIVES

To characterize the limitations of self-expandable stents in the management of benign tracheal stenosis, we performed a retrospective review at a tertiary care medical center.

METHODS

Patients who underwent tracheal stenting were assessed for the cause and severity of tracheal stenosis, comorbidities, stent-related complications, and follow-up airway procedures.

RESULTS

Sixteen adults (12 women, 4 men; mean age, 47 years) had a total of 26 stents placed for benign disease. Intubation-related stenoses were most frequent (81%). The average follow-up time was 20 months (range, 1 to 40 months). Each stent remained functional for an average of 12.4 months. In the study group, 87% had a complication that required surgical intervention to maintain a patent airway. The most common problem was granulation tissue formation at the ends of the stent causing airway restenosis (81%), and 5 patients (31%) required tracheotomy as a result of restenosis around the stent. Fourteen of the stents (56%) were removed or expelled from the patients.

CONCLUSIONS

The implantation of self-expandable stents is a minimally invasive method of managing benign tracheal stenosis. Although a small subset of patients may benefit from placement, the majority of patients have complications that require intervention to maintain a patent airway. Thoughtful discretion is critical in selecting patients for this intervention.

Tracheal resection with end-to-end anastomosis for benign tracheal stenosis

To review our experience with tracheal resection with end-to-end anastomosis for tracheal stenosis, we performed a retrospective review at a tertiary-care academic medical center. Twenty-eight patients underwent circumferential tracheal resection with end-to-end anastomosis by 2 attending otolaryngologists from 1989 to 2002. Patients were excluded if they were under 12 years of age or if the surgical indication was tracheal or thyroid neoplasm. The indications for tracheal resection were postintubation stenosis (n = 9; 32%), posttracheotomy stenosis (n = 7; 25%), both postintubation and posttracheotomy stenosis (n = 9; 32%), external tracheal trauma (n = 2; 7%), and presence of a foreign body (n = 1; 4%). Two to 8 rings were resected. The follow-up periods ranged from 18 months to 13.5 years. The anastomotic success rate was 89% (n = 25). No patients died as a result of the procedure. We conclude that tracheal resection with end-to-end anastomosis is a relatively safe and reliable procedure for the treatment of tracheal stenosis in appropriately selected patients.