Self-expandable prostheses in the tracheobronchial tree

A systematic review and meta-analysis of prevalence of complications after tracheal stenting in dogs

BACKGROUND

Stenting has become popular to treat tracheal collapse in dogs, but complications might arise and negatively affect treatment outcome.

OBJECTIVES

Determine the overall prevalence of complications of tracheal stenting in dogs.

METHODS

A bibliographic search was performed of publications from 2000 to 2020. Studies were assessed for quality of evidence and measured prevalence of the 8 most commonly reported complications after tracheal stenting in dogs (stent fracture, stent migration, relapsing collapse, granuloma formation, tracheobronchial infections, and early, late, and clinically relevant late cough). Random effects meta-analyses were used to estimate pooled complications prevalence.

RESULTS

Fifteen studies met inclusion criteria. Cough (early: 99%; 95% confidence interval [95% CI]: 95%-100%, late: 75%; 95% CI: 63%-85%, and clinically relevant: 52%; 95% CI: 42%-61%), tracheobronchial infections (24%; 95% CI: 14%-35%), and granulomas (20%; 95% CI: 11%-30%) were common after tracheal stenting. Stent fractures (12%; 95% CI: 5%-20%), relapsing collapse (10%; 95% CI: 5%-15%), and stent migration (5%; 95% CI: 1%-9%) were less frequent. Significant heterogeneity among studies was identified for the estimated prevalence of stent fracture, granulomas, infections, and late cough.

CONCLUSIONS AND CLINICAL IMPORTANCE

Tracheal stenting in dogs is associated with a high risk of coughing and a moderate risk of tracheobronchial infections and granuloma formation. Because most complications will impact a dog's quality of life, owners must be informed that tracheal stenting is a second-line procedure that does not necessarily alleviate the need for medical treatment and frequent follow-up visits. Additional studies are warranted to identify the risk factors of these complications.

Advancements in airway stents: a comprehensive update

PURPOSE OF REVIEW

This review provides an overview of the evolving field of airway stenting (AS), highlighting its relevance in the management of central airway obstruction (CAO). It discusses recent advancements, including 3D-printed silicone stents (3DPSS), metallic stents, biodegradable stents (BS), and drug-eluting stents (DES), which are transforming clinical practice. The review underscores the ongoing challenges in patient selection, stent choice, and long-term management in the context of an evolving landscape.

RECENT FINDINGS

Innovations, particularly 3DPSS, have shown promise in providing patient-specific solutions. These stents offer improved symptom relief, enhanced quality of life, and lower complication rates, especially for complex airway diseases. The use of BS and DES is explored, raising prospects for future applications.

SUMMARY

The evolution of AS reflects a deepening understanding of airway obstructions. Recent innovations, such as 3DPSS, BS, and DES, show considerable promise in addressing the limitations of conventional stents. However, challenges related to complications, patient selection, and long-term management persist, demanding further research. Wide practice variations in the management of AS highlight the need for more clinical data and standardized guidelines. The search for the ideal stent continues, driven by the pursuit of better outcomes for patients with CAO.

Special Considerations and Techniques of Interventions in Lung Transplant Recipients

Lung transplant remains an important treatment option for patients with end-stage lung diseases providing improvement in survival rates and quality of life. Specialized considerations should be applied with interventions of lung transplant recipients as they host specific anatomic variations and high risk towards certain complications. In this article, we highlight the role of interventional radiology for lung transplant recipients along with discussion of interventional techniques. Specific emphasis is placed on describing and explaining the techniques pertained to the points of anastomosis, diagnosis and treatment of malignancies, and management of complications in lung transplant recipients.

Long-term outcomes of tracheal stents removal under fluoroscopy guidance: comparison of tracheal fistulas and tracheal stenosis

Background

Endoscopic removal is the most common method for removal of tracheal stents. Few studies have reported the technique of fluoroscopy-guided stent removal for tracheal fistula and tracheal stenosis. We aimed to study the safety and efficacy of fluoroscopy-guided stent removal as well as the optimal duration for stent usage.

Methods

We conducted a retrospective analysis of 152 patients who underwent fluoroscopy-guided stent removal from January 2011 to June 2017. Reasons for stent implantation were tracheal fistula in 85 patients (TF group), and tracheal stenosis in 67 patients (TS group). All patients underwent tracheal CT scans before stent removal and during follow up. The technical success rate, complications, and survival rate were compared between the two groups.

Results

The technical success rate of stent removal was 98.9 and 97.4%, respectively for the TF and TS group. Removal was routine for half of patients, and in the remainder, excessive granulation tissue was the common indications for stent removal, which was found after stenting at 142.1 ± 25.9 days in the TF group, and at 89.9 ± 15.0 day in the TS group. The total incidence of complications was 21.1 and 22.4%, respectively, for the TF and TS groups. Perioperative death occurred in one patient in the TF group, and two patients in the TS group. Recurrence of fistula or stenosis requiring re-stenting was the most comment complication in both groups. The 0.5-, 3-, 6-year survival rates were 90.3, 59.6, and 36.1% for TF group, and 80.4, 75.7, 75.7% for TS group.

Conclusions

Fluoroscopic removal of tracheal stents is safe and effective for both tracheal fistula and tracheal stenosis, with no significant difference in outcomes. Clinicians should pay attention to the risk of hemoptysis for patients with malignant tumors and a combination with endoscopic hemostasis may help improve its safety.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12890-020-01349-7.

Removal of Self-Expanding Metallic Stents

BACKGROUND

Despite their safety profile, self-expanding metallic stents (SEMS) have been difficult to remove. We aim to describe our experience in removal of SEMS at Henry Ford Hospital with a specific emphasis on safety.

METHODS

We reviewed the charts of all patients who underwent removal of a SEMS at Henry Ford Hospital between 2003 and 2013. We recorded demographic information, indication for initial stent placement, indication for stent removal, time to stent removal, procedure of removal, and any complications.

RESULTS

In all, 19 stents were removed in 16 separate procedures in 14 patients. The median age was 62 years, and 50% of the patients were female. Stents were removed at a median of 35 days (range, 2 to 595 d). No complications occurred in 10/16 (62.5%) procedures. In the remaining 5 patients, complications were not directly related to the stent removal, and serious complications were mostly related to severity of underlying lung disease. Of the 10 procedures done as outpatients, 70% were discharged immediately after the procedure.

CONCLUSIONS

Removal of SEMS can be done safely. Routine postoperative ventilation and intensive care unit monitoring is not required. In the absence of severe underlying lung disease, patients can safely be discharged if there are no immediate postprocedure complications.

Self-expandable metallic stents in nonmalignant large airway disease

Airway self-expandable metallic stents (SEMS) were initially studied in malignant airway obstruction; however, their use in benign airway diseases has become progressively more frequent. This may be explained by their ease of insertion compared with silicone stents, which require rigid bronchoscopy for insertion. While initial experience with SEMS in benign disease suggested efficacy and promising short-term safety profile, long-term follow-up revealed significant complication rates. In addition to a high complication rate, the management of these complications is made more difficult by the semipermanent nature of these devices. Reported complications include infection, granulation tissue formation, stent migration, stent fracture, airway perforation and fistula formation, as well as extension of the initial injury, potentially eliminating other therapeutic options such as surgical resection. Therefore, SEMS should only be used in nonmalignant large airway disease as a last resort for patients in whom other endoscopic methods, including silicone stents and dilations, as well as surgical options have failed or are technically not feasible.

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.

Self-Expandable Metallic Stent Placement in Malignant Gastric Outlet Obstruction: A Comparison Between 2 Brands of Stents

Malignant gastric outlet obstruction is a late complication of intraabdominal malignancy. Self-expandable metallic stent placement has been a safe palliative treatment to relieve obstructive symptoms. We aimed to assess the efficacy and safety of metallic stents in our patients and analyzed the clinical outcome of different brands. Seventy-one patients with inoperable gastric outlet obstruction receiving WallFlex enteral stents (WallFlex group) or Bonastents (Bonastent group) since April 2010 were analyzed retrospectively. The overall technical and clinical success rates of stent placement were 100% and 93%, respectively. The baseline characteristics and clinical outcomes including procedure-related complications, restenosis, and reintervention rates were comparable between the 2 groups. However, the Bonastent group had a higher rate of stent fracture than the WallFlex group (13.3% vs 0%, P = 0.03). The mean duration of overall stent patency was 132.7 days. The mean duration of survival was 181.9 days. Resumption of regular diet or low residual diet at day 7 after stent insertion predicted stent patency (hazard ratio [HR]: 0.28, P = 0.01). Cancer with gastric origin (HR: 0.25, P = 0.045) and poststent chemotherapy (HR: 0.38, P = 0.006) predicted lower mortality; however, peritoneal carcinomatosis (HR: 3.09, P = 0.04) correlated with higher mortality. Metallic stent placement is a safe and effective method for relieving gastric outlet obstruction. Except higher rate of stent fracture in the Bonastent group, there is no significant difference in clinical outcomes between the Bonastent group and the WallFlex group.

Interventional oncology in multidisciplinary cancer treatment in the 21(st) century

Interventional oncology is an evolving branch of interventional radiology, which relies on rapidly evolving, highly sophisticated treatment tools and precise imaging guidance to target and destroy malignant tumours. The development of this field has important potential benefits for patients and the health-care system, but as a new discipline, interventional oncology has not yet fully established its place in the wider field of oncology; its application does not have a comprehensive evidence base, or a clinical or quality-assurance framework within which to operate. In this regard, radiation oncology, a cornerstone of modern cancer care, has a lot of important information to offer to interventional oncologists. A strong collaboration between radiation oncology and interventional oncology, both of which aim to cure or control tumours or to relieve symptoms with as little collateral damage to normal tissue as possible, will have substantial advantages for both disciplines. A close relationship with radiation oncology will help facilitate the development of a robust quality-assurance framework and accumulation of evidence to support the integration of interventional oncology into multidisciplinary care. Furthermore, collaboration between interventional oncology and radiation oncology fields will have great benefits to practitioners, people affected by cancer, and to the wider field of oncology.

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

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

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.

Broncho-vascular fistulas from self-expanding metallic stents: A retrospective case review

To highlight a potentially fatal complication of broncho-vascular fistula arising from the self expanding metallic stent (SEMS) placement. We retrospectively analyzed five patients with benign and malignant airway diseases, who developed tracheo/broncho-vascular fistulas following SEMS placement in our tertiary care setting. All patients received either Wallstent or Ultraflex^® stent (Boston Scientific, Natick, MA) between 1999 and 2007. All patients had received adjunct therapy such as balloon bronchoplasty, laser therapy or electrocautery. Most patients presented with massive hemoptysis. A total of 483 SEMS were placed during this period. SEMS placement can be complicated by Broncho-vascular fistula formation. True incidence and precise time interval between the insertion of stent and onset of this complication is unknown. Additional therapeutic modalities to maintain stent patency may enhance the risk of fistula formation. SEMS should only be used in a select sub-group of patients, after exhaustive evaluation of other treatment options. These cases provide evidence that broncho-vascular fistulas can develop at any time following SEMS placement, suggesting the need for a more cautious approach, especially while using them for a long term management. In benign airway disease, the stent should be removed as soon as healing has taken place.

An instant rare complication: a fractured metallic pyloric stent

Metallic pyloric stenting (also termed as metallic enteral stenting) performed endoscopically, stands as first-line treatment for malignant gastric outlet obstruction. With reported evidence, these self-expandable metallic stents (SEMS) re-enable oral food intake, preventing patients having to face invasive techniques such as surgical gastroenterostomy. We report a patient having received a covered pyloric SEMS insertion following a tumour growth causing stenosis in the gastric antropyloric region. After 3 weeks, the patient presented with a fracture of the pyloric SEMS, a rare complication, resulting in a second pyloric SEMS insertion.

Update in airway stents

PURPOSE OF REVIEW

Malignant central airway obstruction heavily impacts patients' quality of life and its management continues to be a challenge. The current article will review the use of airway stents in this population.

RECENT FINDINGS

Airway stenting is highly effective in palliating symptoms of airway obstruction. There are several types of stents available with different advantages and disadvantages depending mainly on the material they are made from. Clinical outcomes seem to be comparable between silicone and self-expanding metal stents. Self-expanding metal stents have proven to be efficient in recanalizing 'complex' central airway obstructions. Preliminary data show that a new self-expanding 'hybrid' stent appears to be effective and safe for malignant airway obstruction. Airway stent complications vary according to the type of stent and the type of obstruction. Multidetector computed tomography seems to be a valuable adjunct to bronchoscopy in detecting and characterizing stent complications. A clear definition of airway stent-related infection is urgently needed to provide adequate diagnosis and management of this complication. Metal stent fracture is less common in patients with malignant airway obstruction as compared with benign disease, and this could be partially explained by the decreased survival and shorter exposure to stent in the former population.

SUMMARY

Airway stents are of great help in palliating symptoms of malignant central airway obstruction. Unfortunately, there have been no recent striking advances in stent technology and the ideal stent has yet to be designed.

Efficacy and tolerability of airway stents

The function of airway stents is to keep the tubular structures open and stable. Their insertion is essentially indicated for intrinsic obstruction or extrinsic compression of the airway, fistulae or tracheobronchomalacia. The aim of this study was to determine the tolera bility and efficacy of airway stents in situations in which their insertion was vital. A retrospective study of airway stent insertion with rigid bronchoscopy (23 patients) was carried out over a two year period (2006-2007) at the Diagnostic and Therapeutic Techniques Unit. We assessed indication, efficacy, tolerability, complications and exact insertion based on chest CT imaging. In all situations Dumon flexible silicon stents (Tracheobronxane were used, with the need for complementary techniques such as laser therapy and mechanical dilation having been previously evaluated by flexible bronchoscopy. The authors conclude that stent insertion has no complications and good tolerability in the majority of advanced stage oncological situations with indication for palliative management.

Factors leading to tracheobronchial self-expandable metallic stent fracture

OBJECTIVE

This retrospective study was to determine factors that contribute to self-expandable metallic stent fracture in patients with tracheobronchial disease.

METHODS

From 2001 to 2006, 139 patients (age, 62.1 +/- 15.4 years; range, 23-87 years) with benign (n = 62) and malignant (n = 77) tracheobronchial disease received 192 Ultraflex (Boston Scientific, Natick, Mass) self-expandable metallic stents (98 in patients with benign disease and 94 in patients with malignant disease).

RESULTS

Seventeen fractured self-expandable metallic stents were found; the incidence was 12.2% (17/139 patients) among patients with tracheobronchial disease. Tortuous airway (odds ratio, 4.06; 95% confidence interval, 1.04-18.34; P = .04) independently predicted self-expandable metallic stent fracture. Most self-expandable metallic stent fractures (64.7%, 11/17) were detected 500 to 1000 days after self-expandable metallic stent implantation. Clinical presentations for patients with fractured self-expandable metallic stents included dyspnea exacerbation (70.6%, 12/17) and cough (23.5%, 4/17).

CONCLUSIONS

Self-expandable metallic stent fracture is not uncommon in patients with tracheobronchial disease. Tortuous airway is an independent predictor for it. Although management of the fractured self-expandable metallic stent in our study was feasible and safe, self-expandable metallic stents should be restricted to a more select population.

Clinical benefits and complications of Dumon stent insertion for the treatment of severe central airway stenosis or airway fistula

OBJECTIVES

The purpose of this study was to evaluate the clinical benefits and complications of Dumon stent insertion for patients with central airway disorders including stenosis and fistula.

METHODS

This was a retrospective analysis of medical records regarding alleviation of symptoms, occurrence of complications, and technical problems. Since August 1998, the Dumon stent has been used in 35 consecutive patients, included 24 with malignant airway stenosis, 5 with benign stenosis, and 6 with airway fistula. Altogether, 7 patients had a straight stent inserted into the trachea, 17 had a Y-stent inserted into the carina, and 11 patients had a straight stent inserted into the bronchus.

RESULT

In 33 of the 35 patients, the symptoms dramatically diminished after stent insertion. Poststenting complications included increased coughing in 37% of the patients, an obstruction of the stent due to secretion in 8.6%, migration in 5.7%, granulation in 2.9%, and cerebral infarction in 2.9%. Ten patients had the stent removed for various reasons, and five of the ten underwent reinsertion of a new stent. Migration could be avoided by external fixation with nylon threads in the upper trachea. Three of six patients with an airway fistula showed resolution of the fistula, and the remaining three patients improved symptomatically. Five of these six patients had undergone radiotherapy prior to stent insertion.

CONCLUSIONS

The Dumon stent was found to be effective for treating not only airway stenosis but also airway fistula, with permissible complications. The Dumon stent is therefore considered to be the most effective airway stent presently available worldwide based on both cost and safety factors.

Tracheal replacements: part 1

In this review, we summarize the history of tracheal reconstruction and replacement as well as progress in current tracheal substitutes. In Part 1, we cover the historical highlights of grafts, flaps, tube construction, and tissue transplants and address the progress made in tracheal stenting as a means of temporary tracheal support. This is followed in Part 2 by an analysis of solid and porous tracheal prostheses in experimental and clinical trials. We conclude Part 2 with a summary of recent efforts toward generating a bioengineered trachea. Finally, we provide an algorithm on the spectrum of options available for tracheal replacement.

Endobronchial stent placement for the management of airway complications after lung transplantation

PURPOSE

To retrospectively evaluate the efficacy and complications of endobronchial stent placement for the management of airway complications following lung transplant.

MATERIALS AND METHODS

From 1992 to 2003, tracheobronchial stenting was performed on 25 lung transplant recipients (16 male and 9 female; mean age 51.6 years; range 21-65 years). A total of 27 lesions were treated and 27 stents were deployed (nine bronchomalacia, 12 bronchial stenosis, three bronchial stenosis and bronchomalacia both and three anastomotic dehiscence). The clinical and bronchoscopic follow-up ranged from 1 month to 69 months.

RESULTS

The technical success was 100%. Eighty-four percent of patients had immediate relief in dyspnea. The overall complication rate following stent placement was 0.049 per patient per month (23 complications/471 patient months). Stent migration and granulation tissue formation were the most frequent complications. The mean percentage change in FEV-1 was significantly greater than zero at 1 month and 6 months (P<.05) post-stent placement. The mean percentage change in FEV-1 was marginally greater than zero at 12 months (P=.07).The mean percentage change in FVC was marginally greater than zero at 1 month and 6 months (P=.08) post-stent. It was not significantly greater than zero at 12 months (P=1.00).

CONCLUSION

Tracheobronchial stent placement provides effective palliation of postoperative airway complications in lung transplant with morbidity that can be managed effectively by available treatment options. Airway stenting may be used as a primary management option for airway complications after lung transplantation as a large number of patients are not suitable candidates for repeat surgery.

Benign tracheobronchial strictures: long-term results and factors affecting airway patency after temporary stent placement

OBJECTIVE

The purpose of our study was to evaluate long-term results and identify factors affecting airway patency after temporary placement of a covered, retrievable nitinol stent for benign tracheobronchial strictures.

MATERIALS AND METHODS

Polyurethane or polytetrafluoroethylene (PTFE)-covered retrievable expandable nitinol stents were placed fluoroscopically in 24 patients with benign tracheobronchial strictures. Improvement in respiratory status and complications were evaluated. Maintained patency of airway after temporary stenting was calculated and compared between the 2- and 6-month stenting groups. Factors for maintained patency after temporary stenting were evaluated.

RESULTS

A total of 30 stents were successfully placed and well tolerated in 24 patients. Tissue hyperplasia, stent migration, and bronchial obstruction of the left upper lobe occurred in 36.7%, 13.3%, and 3.3% of patients, respectively. All stents were successfully removed electively either 2 (n = 12) or 6 (n = 12) months after placement or when complications occurred (n = 6). During the follow-up period (mean, 24 months), dyspnea recurred in 15 of the 24 patients. The 6-month stenting group showed a lower recurrence rate (41.7% vs 83.3%, p = 0.045) and a better mean maintained patency (39.7 +/- 7.8 vs 9.4 +/- 5.4 months, p = 0.001) than the 2-month stenting group. Multivariate analysis showed that duration of stent placement (p = 0.002) and the occurrence of tissue hyperplasia (p = 0.026) were associated with maintained patency after temporary stenting.

CONCLUSION

Temporary placement of a covered, retrievable, expandable nitinol stent may be a safe and effective treatment for benign tracheobronchial strictures during the period the stent is in place. A high symptomatic recurrence rate of 62.5% was found after stent removal. Shortterm placement of the stent and tissue hyperplasia were associated with decreased airway patency.

Intraluminal Tracheal Stenting for Treatment of Tracheal Narrowing in Three Cats

OBJECTIVE

To describe the use of intraluminal tracheal stenting in 3 cats with either benign or malignant tracheal obstruction.

STUDY DESIGN

Retrospective clinical study.

ANIMALS

Three client-owned cats.

METHODS

Medical records were reviewed and information regarding signalment, clinical signs, physical examination findings, diagnostic tests performed, treatment, outcome and follow-up were retrieved. Intraluminal tracheal stent placement was performed as previously described in the literature.

RESULTS

Three cats received intraluminal tracheal stents for the treatment of tracheal obstruction due to 3 different underlying causes: stricture secondary to traumatic endotracheal intubation, stricture secondary to a previous tracheotomy, and neoplasia. Self-expanding metallic stents of varying sizes were placed, and all cats recovered uneventfully from the procedures. The cat with tracheal neoplasia was euthanized because of pulmonary metastatic disease 6 weeks post-stent placement. The two cats with tracheal obstructions secondary to benign strictures are currently 39 months and 32 weeks post-stent placement, respectively. No complications were noted during the post-stent period in any of the 3 cats.

CONCLUSIONS

Intraluminal tracheal stenting was easily, safely, and rapidly performed without complications and resulted in immediate improvement in clinical signs in all three cases. None of the cats in this study developed significant stent-associated complications during the study period.

CLINICAL RELEVANCE

Intraluminal tracheal stenting has the potential to be a viable option for the treatment of tracheal obstruction in cats and perhaps for similar disease processes in other veterinary patients.

Fracture of an expandable metallic stent placed for biliary obstruction due to common bile duct carcinoma

We report our second case of fracture of a SMART self-expandable metallic stent (Cordis Endovascular, Warren, NJ) placed to treat biliary obstruction due to an unresectable common bile duct carcinoma. An 82-year-old man presented with jaundice. Computed tomography and ultrasonography on admission demonstrated a mass in the lower common bile duct. The mass was identified as a common bile duct obstruction. A SMART stent was inserted. Ten months after stent insertion, two additional SMART stents were inserted to relieve obstructive jaundice due to occlusion of the first stent. Fourteen months after insertion of the first stent, endoscopic examination revealed stenosis of the duodenum due to invasion of the common bile duct carcinoma, prompting us to perform a gastrojejunostomy 1 month later. Three months after gastrojejunostomy, the patient presented with obstructive jaundice and cholangitis. A fracture of one of the stents was then discovered on plain X-ray films and percutaneous transhepatic cholangiography. Two SMART stents were inserted simultaneously. In conclusion, we report the fracture of a SMART stent placed for common bile duct carcinoma. Fracture should be considered as a possible complication after metallic stent insertion.

Outcomes of Tracheobronchial Stent Placement for Benign Disease

PURPOSE

To retrospectively determine long-term outcomes in patients who have undergone tracheobronchial stent placement for benign diseases.

MATERIALS AND METHODS

Institutional Review Board approval was obtained for this retrospective HIPAA-compliant study, with waiver of informed consent. Forty patients (22 female, 18 male; mean age, 52.0 years) who were treated with metallic airway stents for benign stenosis were identified from an interventional radiology database. Causes of airway stenosis included transplant stricture (n = 13), tracheal tube injury (n = 10), inflammation (n = 6), tracheobronchomalacia (n = 4), infection (n = 3), and extrinsic compression (n = 4). Follow-up, which ranged from 6 to 2473 days, was performed by means of chart review for deceased patients and by means of clinical visit or telephone interview for surviving patients. Survival, primary patency, and assisted patency were estimated by using the Kaplan-Meier product limits method.

RESULTS

Initial technical success was achieved in all cases. Symptomatic improvement was present in 39 of 40 cases. At review, 15 patients were alive and had clinical improvement, 18 had died of comorbid causes, one had died of uncertain causes, three had undergone subsequent airway surgery, two had undergone airway stent retrieval, and one was lost to follow-up. Survival at 1, 2, 3, 4, 5, and 6 years was 79%, 76%, 51%, 47%, 38%, and 23%, respectively. Loss of primary patency was most rapid during the 1st year. With repeat intervention, assisted patency was 90% at 6.8 years.

CONCLUSION

Attrition of tracheobronchial stent patency is most rapid during the 1st year, and a high rate of long-term patency can be achieved with secondary interventions. Metallic airway stents are well-tolerated and useful adjuncts for management of select benign tracheobronchial stenoses.

Fixation of silicone stents in the subglottic trachea: preventing stent migration using a fixation apparatus

Silicone stents are widely used to treat benign or malignant airway stenosis. However, since straight silicone stents placed into the subglottic trachea to treat stenosis display a high risk of migration, novel approaches are required. The present report outlines our method of external fixation for silicone stents in the subglottic trachea. This technique utilizes a fixation apparatus, is readily performed, and may help to overcome the hesitation seen in placing silicone stents for subglottic tracheal stenosis.

Endoscopic Removal of Metallic Airway Stents

BACKGROUND

Complications of metallic airway stents include granulation tissue formation, fracture of struts, migration, and mucous plugging. When these complications result in airway injury or obstruction, it may become necessary to remove the stent. There have been few reports detailing techniques and complications associated with endoscopic removal of metallic airway stents. We report our experience with endoscopic removal of 30 such stents over a 3-year period.

METHODS

We conducted a retrospective review of 25 patients who underwent endoscopic stent removal from March 2001 to April 2004. The patients ranged in age from 17 to 80 years (mean, 56.3 years). There were 10 male and 15 female patients. The stents had been placed for nonmalignant disease in 20 patients (80%) and malignant disease in 5 patients (20%). All procedures were done under general anesthesia with a rigid bronchoscope. Special attention was focused on the technique of stent removal and postoperative complications.

RESULTS

Thirty metallic airway stents were successfully removed from 25 consecutive patients over a 3-year period. The basic method of removal involved the steady application of traction to the stent with alligator forceps. In all cases, an instrument such as the barrel of the rigid bronchoscope or a Jackson dilator was employed to help separate the stent from the airway wall before removal was attempted. In some instances, the airway wall was pretreated with thermal energy prior to stent removal. Complications were as follows: retained stent pieces (n = 7), mucosal tear with bleeding (n = 4), re-obstruction requiring temporary silicone stent placement (n = 14), need for postoperative mechanical ventilation (n = 6), and tension pneumothorax (n = 1).

CONCLUSIONS

Although metallic stents may be safely removed endoscopically, complications are common and must be anticipated. Other investigators have described airway obstruction and death as a result of attempted stent removal. Placement and removal of metallic airway stents should only be performed at centers that are prepared to deal with the potentially life-threatening complications.

Tracheomalacia and Tracheobronchomalacia in Children and Adults

Tracheomalacia and tracheobronchomalacia are disorders that are encountered in both pediatric and adult medicine. Despite increasing recognition of these disease processes, there remains some uncertainty regarding their identification, causes, and treatment. This article is intended to be a comprehensive review of both the adult and pediatric forms of the diseases, and includes sections on the historical aspects of the disorders, and their classification, associated conditions, histopathology, and natural history. We also review the various modalities that are used for diagnosis as well as the state of the art of treatment, including airway stent placement and surgical intervention.

Removal of Covered Self-Expandable Metallic Airway Stents in Benign Disorders

STUDY OBJECTIVES

To describe the technique and outcome of removal of self-expandable metallic airway stents (SEMAS) in a series of patients who underwent stenting for benign airway stenoses.

DESIGN AND SETTING

A retrospective cohort analysis of patients with benign airway disorders treated with SEMAS between 1997 and 2003, who presented with an indication for stent removal in a tertiary-care hospital, and referral interventional pulmonology clinic.

PATIENTS AND METHODS

During the study period, 49 SEMAS were inserted in 39 patients for treatment of benign airway disorders. Ten of these 39 patients (25.6%), bearing 12 covered stents, presented with an indication for stent removal. Data of these cases were extracted from electronic files kept in our institution archive.

RESULTS

Indications for stent removal included excessive or recurrent granuloma formation (five cases), recurrence of stenosis after stent failure (one case), stent fracture (two cases), and accomplishment of treatment (two cases). In all of these cases, covered versions of SEMAS had been placed either in the trachea or in a main bronchus. In contrast to many previous reports, these stents proved to be absolutely retrievable even if some difficulties were encountered. In all cases, however, removal was successful without major complications. All patients resumed normal spontaneous ventilation postoperatively, and follow-up was uneventful. Average duration of stenting before removal was 16.2 +/- 17.5 months (+/- SD) [range, 1 to 60 months].

CONCLUSIONS

We conclude that although placement of SEMAS is assumed to be permanent in patients with benign airway disorders, an indication for stent removal is often observed (25.6% in our series). The covered SEMAS can be effectively and safely removed if needed without major sequelae. Nevertheless, new technical improvements in metallic stent design and materials may help reinforce the concept of a retrievable metallic airway stent, which may offer significant clinical advantages.

Central Airway Obstruction

Central airway obstruction is a problem facing all medical and surgical subspecialists caring for patients with chest diseases. The incidence of this disorder appears to be rising because of the epidemic of lung cancer; however, benign causes of central airway obstruction are being seen more frequently as well. The morbidity is significant and if left untreated, death from suffocation is a frequent outcome. Management of these patients is difficult, but therapeutic and diagnostic tools are now available that are beneficial to most patients and almost all airway obstruction can be relieved expeditiously. This review examines current approaches in the workup and treatment of patients suffering from airway impairment. Although large, randomized, comparative studies are not available, data show significant improvement in patient outcomes and quality of life with treatment of central airway obstruction. Clearly, more studies assessing the relative utility of specific airway interventions and their impact on morbidity and mortality are needed. Currently, the most comprehensive approach can be offered at centers with expertise in the management of complex airway disorders and availability of all endoscopic and surgical options.

Malignant tracheobronchial strictures: palliation with covered retrievable expandable nitinol stent

PURPOSE

To evaluate the safety and clinical effectiveness of a covered retrievable expandable nitinol stent for the treatment of malignant tracheobronchial stricture and/or esophagorespiratory fistula (ERF).

MATERIALS AND METHODS

With fluoroscopic guidance, stents were placed in 35 symptomatic patients with malignant tracheobronchial stricture and/or ERF in most cases caused by lung or esophageal cancer. The site of stricture was most commonly at the trachea or left main bronchus. If there were complications, the stent was removed with a retrieval set. Nine patients had combined symptomatic ERF.

RESULTS

A total of 47 tracheobronchial stents were placed and were technically successful and well-tolerated in all patients. Improvement of dyspnea was achieved in 92% of the patients (24 of 26 patients). Associated ERF in nine patients was effectively treated with tracheobronchial stent placement with or without esophageal stent placement. Stent migration, tumor overgrowth, symptomatic sputum retention, and hemoptysis occurred in 17% (6/35), 6% (2/35), 20% (7/35), and 17% (6/35) of patients, respectively. There were no documented cases of tumor ingrowth. Stent removal was performed easily in five patients when stent migration (n = 2), severe pain (n = 1), tumor overgrowth (n = 1), or persistent gastrobronchial fistula (n = 1) developed. All patients died 2 days to 26 weeks (mean, 9.62 weeks) after stent placement because of disease progression (n = 18), pneumonia (n = 9), hemoptysis (n = 5), or unknown cause (n = 3).

CONCLUSION

Use of a covered retrievable expandable nitinol stent is a safe and effective method for relieving dyspnea. This procedure contributed to improved quality of life for patients with malignant tracheobronchial stricture and/or ERF. Stent retrievability was useful in resolving stent-related complications.

Self-expandable metallic airway stents and flexible bronchoscopy: long-term outcomes analysis

STUDY OBJECTIVE

s: To report and analyze our 6-year experience with implanting 112 self-expandable metallic stents (SEMSs) using flexible bronchoscopy (FB).

DESIGN AND SETTING

Retrospective study, tertiary-care hospital.

PATIENTS AND METHODS

The studied population consisted of 82 patients (mean age, 59.1 years; range, 37 to 83 years), who received SEMSs from 1995 to 2001 using Wallstent (Boston Scientific; Galway, Ireland) or Ultraflex (Boston Scientific) stents.

RESULTS

The indications for stent placement were airway obstruction caused by neoplasia (lung carcinoma [CA], n = 50), airway complications of lung transplantation (LTx) [n = 11], and miscellaneous benign conditions (BCs) [n = 21]. The most frequent clinical presentations for the airway obstruction were moderate-to-severe dyspnea (80%) and coughing (45%). The median follow-up duration for the CA group was 42.0 days (range, 1 to 672 days), 329.0 days (range, 35 to 1,540 days) for patients receiving LTx, and 336.0 days (range, 7 to 2,184 days) for the patients with miscellaneous BCs. The observed complications included infection (15.9%), obstructive granulomas (14.6%), and migration (4.7%). The incidence of granulomas was significantly lower in the patients with CA (4.0%) vs LTx and BC groups (17.3% and 33.3% respectively; p = 0.002). All other assessed variables showed no difference between the three analyzed groups. No cases of mucus plugging or fatal hemoptysis were observed. Forty-four patients (53.7%) had no complications related to the SEMS. The incidence of complications was not related to the type of stent (Wallstent or Ultraflex) or SEMS version (covered or uncovered). Fourteen of the 16 patients (87.5%) who were receiving mechanical ventilation could be weaned after the procedure. There were no deaths related to SEMS placement.

CONCLUSIONS

An SEMS is a safe and effective modality for malignant as well as selected benign airway obstruction. An SEMS is an acceptable therapeutic alternative in patients with central airway obstruction who are not considered good surgical candidates and are receiving mechanical ventilation. Careful patient selection is of outmost importance for a good outcome after airway stenting. Insertion using FB adds to the ease of the procedure.

Bronchoscopic insertion of Gianturco stents for the palliation of malignant lung disease: 10 year experience

Malignant large airway obstruction is life threatening and may not be amenable to urgent radiotherapy. Palliative airway stenting is difficult and traditionally carried out under general anaesthesia and fluoroscopy. We have shown that self expanding Gianturco metal stents can be placed under local anaesthesia using fibreoptic bronchoscopy and direct vision for the treatment of malignant airway tumours, and report our 10 year experience. All referrals for stenting referred to our unit between 1990 and 1999 were included, looking for histological type, number and site of stents, complications of the procedure, other interventions, and survival. One hundred and sixty two patients (average age 64 years, (range 21-89)) had 307 stents inserted during 167 procedures (144 primary lung tumours, 18 secondary malignancy). There were no operative deaths, but three patients developed a pneumothorax, one requiring intercostal drain insertion. Average survival following stent insertion was less for primary lung cancer than for secondary disease (103 vs. 431 days, P<0.001). There were no excess complications in a subgroup of 64 patients treated locally by oncologists, even when stenting was the primary procedure. This technique is useful in palliating life threatening airway obstruction, particularly for secondary cancer, and can be used in any centre undertaking fibreoptic bronchoscopy.

Saber-sheath malacic trachea remodeled and fixed into a normal shape by long-term placement and then removal of gianturco wire stent

We report the case of a 59-year-old man who presented with major dyspnea due to saber-sheath malacic trachea associated with chronic pulmonary obstructive disease. The placement of a temporary tracheal stent alleviated his dyspnea very well; hence the stent was replaced with a Gianturco wire stent (Cook Cardiology, Bloomington, IN). However, this required removal due to wire-stent-related complications 2 years after the replacement. Surprisingly the trachea had been remodeled to a normal shape resulting in comfortable, functional respiratory status. A review of the literature reveals our case to be the first report of curing saber-sheath malacic trachea without leaving any prostheses or other foreign materials.

The role of self-expandable metallic stents for the treatment of airway complications after lung transplantation

BACKGROUND

Airway complications continue to be an important source of morbidity and mortality after lung transplantation (LTx). Different approaches have been used for their nonsurgical management. We describe our experience using self-expandable metallic stents (SEMSs) in patients with airway complications post-LTx.

METHODS

We present a retrospective analysis of stent related-data of all the LTx patients who received SEMSs to treat postoperative airway complications.

RESULTS

Between January 1992 and December 2001, 36 of 253 patients (14.2%) developed post-LTx airway complications involving 40 of 348 anastomoses (11.5%). A total of 15 SEMSs were placed in 12 patients (mean age 47.3+/-9.6 years) for tracheobronchomalacia, stenosis, and anastomotic dehiscence, including one patient referred from an outside hospital. Mean follow-up was 20.1+/-19.5 months (range 1.2-58 months). Patency and symptom improvement were achieved in 11 of 12 patients. Stenting of the airway led to successful weaning of two patients who were on prolonged mechanical ventilation. Suture dehiscence was effectively managed in two patients who were not candidates for surgical repair. Overall, the complication rate was 0.040 complications per patient per month (total number of complications and total number of months using the stent). Bacterial bronchitis (four patients) and obstructive granulomas (three patients) were the most frequent complications. The survival of LTx patients with airway SEMSs was similar when compared with the survival of all other LTx patients (P=0.74).

CONCLUSIONS

SEMSs are safe and effective in the management of airway complications in selected patients post-LTx. Weaning from mechanical ventilation and management of anastomotic dehiscence are the unique attributes of this device.