AIRWAY STENTS

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.

Prognostic Factors for Tracheal Restenosis after Stent Removal in Patients with Post-Intubation and Post-Tracheostomy Tracheal Stenosis

PURPOSE

Long-term tracheal stent placement can increase the risk of stent-related complications; hence, removal of the stent after stabilization is attempted. However, little evidence has been established regarding the risk factors for tracheal restenosis. We aimed to identify the risk factors for tracheal restenosis in patients with post-intubation tracheal stenosis (PITS) and post-tracheostomy tracheal stenosis (PTTS).

MATERIALS AND METHODS

We retrospectively analyzed patients with PITS and PTTS between January 2004 and December 2019. Patients were classified into a success or failure group according to treatment outcomes. Patients with successful stent removal were defined as patients who did not require additional intervention after stent removal during the follow-up period. Multiple logistic regression analysis was performed to identify the factors associated with tracheal restenosis.

RESULTS

Among 269 stented patients, 130 patients who had removed the stent were enrolled in this study. During the follow-up period, 73 (56.2%) patients had a stable clinical course; however, 57 (43.8%) patients had restenosis. The proportion of trauma-induced intubation was higher in the success group than in the failure group (p=0.026), and the median stent length was shorter in the success group (45 mm) than in the failure group (50 mm, p=0.001). On multivariate analysis, trauma-induced intubation [adjusted odds ratio (aOR), 0.329; 95% confidence interval (CI), 0.117-0.927; p=0.036], and stent length <50 mm (aOR, 0.274; 95% CI, 0.130-0.578; p=0.001) were associated with a decreased risk of restenosis.

CONCLUSION

Trauma-induced intubation and stent length were associated with successful stent removal.

Angulated Stents-A Novel Stent Improvisation to Manage Difficult Post-tuberculosis Bronchial Stenosis

Post-tuberculosis bronchostenosis (PTBS), a complication of endobronchial tuberculosis is currently treated by bronchial stenting. However, in cases of angulated bronchial stenoses, difficulty is often encountered in stent insertion and maintenance, resulting in stent migration, granulation tissue overgrowth, and restenosis. To accommodate the angulated alignment of the stenosis, we devised an "angulated stent"-a novel improvisation of the conventional stent via splicing and suturing to achieve a resultant angulated shape. A retrospective review was undertaken to evaluate the performance of this stent. Among 283 PTBS patients who underwent interventional bronchoscopy at our center from 2004 to 2014, 21 were treated with at least one angulated stent. Clinical outcomes, including the stenting duration were investigated. After a median follow-up of 26 months, stent removal was successful in 7 (33.3%) out of 21 patients. In patients managed with angulated stents, the median duration to stent change or eventual removal was longer than those treated with straight tube stents (392 days vs. 86 days; p < 0.05). Angulated stents are a feasible treatment option in patients with angulated PTBS by reducing complications and prolonging the stent-changing interval.

Interventional bronchoscopy in malignant central airway obstruction by extra-pulmonary malignancy

Background

Interventional bronchoscopy is considered an effective treatment option for malignant central airway obstruction (MCAO). However, there are few reports of interventional bronchoscopy in patients with MCAOs due to extra-pulmonary malignancy. Therefore, the objective of this study was to investigate treatment outcomes and prognostic factors for bronchoscopic intervention in patients with MCAO due to extra-pulmonary malignancy.

Methods

We retrospectively analyzed consecutive 98 patients with MCAO due to extra-pulmonary malignancy who underwent interventional bronchoscopy between 2004 and 2014 at Samsung Medical Center (Seoul, Korea).

Results

The most common primary site of malignancy was esophageal cancer (37.9%), followed by thyroid cancer (16.3%) and head & neck cancer (10.2%). Bronchoscopic interventions were usually performed using a combination of mechanical debulking (84.7%), stent insertion (70.4%), and laser cauterization (37.8%). Of 98 patients, 76 (77.6%) patients had MCAO due to progression of malignancy, and 42 (42.9%) patients had exhausted all other anti-cancer treatment at the time of bronchoscopic intervention. Technical success was achieved in 89.9% of patients, and acute complications and procedure-related deaths occurred in 20.4% and 3.1% of patients, respectively. Reduced survival was associated with MCAO due to cancer other than thyroid cancer or lymphoma, mixed lesions, and not receiving adjuvant treatment after bronchoscopic intervention.

Conclusions

Bronchoscopic intervention could be a safe and effective procedure for MCAO due to end-stage extra-pulmonary malignancies. In addition, we identified possible prognostic factors for poor survival after intervention, which could guide clinicians select candidates that will benefit from bronchoscopic intervention.

Bronchoscopic techniques in the management of patients with tuberculosis

Tuberculosis (TB) is one of the leading causes of morbidity and mortality worldwide. Early diagnosis and treatment are key to prevent Mycobacterium tuberculosis transmission. Bronchoscopy can play a primary role in pulmonary TB diagnosis, particularly for suspected patients with scarce sputum or sputum smear negativity, and with endobronchial disease. Bronchoscopic needle aspiration techniques are accurate and safe means adopted to investigate hilar and mediastinal lymph nodes in cases of suspected TB lymphadenopathy. Tracheobronchial stenosis represents the worst complication of endobronchial tuberculosis. Bronchoscopic procedures are less invasive therapeutic strategies than conventional surgery to be adopted in the management of TB-related stenosis. We conducted a non-systematic review aimed at describing the scientific literature on the role of bronchoscopic techniques in the diagnosis and therapy of patients with TB. We focused on three main areas of interventions: bronchoscopic diagnosis of smear negative/sputum scarce TB patients, endobronchial TB diagnosis and treatment and needle aspiration techniques for intrathoracic TB lymphadenopathy. We described experiences on bronchoalveolar lavage, bronchial washing, and biopsy techniques for the diagnosis of patients with tracheobronchial and pulmonary TB; furthermore, we described the role played by conventional and ultrasound-guided transbronchial needle aspiration in the diagnosis of suspected hilar and mediastinal TB adenopathy. Finally, we assessed the role of the bronchoscopic therapy in the treatment of endobronchial TB and its complications, focusing on dilation techniques (such as balloon dilation and airway stenting) and ablative procedures (both heat and cold therapies).

Clinical significance of differentiating post-intubation and post-tracheostomy tracheal stenosis

BACKGROUND AND OBJECTIVE

Post-intubation tracheal stenosis (PITS) and post-tracheostomy tracheal stenosis (PTTS) are serious complications in mechanically ventilated patients. Although the aetiologies and mechanisms of PITS and PTTS are quite different, little is known about the clinical impact of differentiating one from the other.

METHODS

We retrospectively conducted a chart review of 117 patients with PITS and 88 patients with PTTS who were treated with interventional bronchoscopy at Samsung Medical Center between January 2004 and December 2013.

RESULTS

Compared to patients with PITS, patients with PTTS had a lower BMI, poorer performance status and more frequent neurological aetiologies, mid-to-lower tracheal lesions, total obstruction and mixed stenosis types. Although there were no differences in the number of patients who received silicone stents between the two groups, Montgomery T-tubes were more frequently used in the PTTS group than in the PITS group. The final success rate without surgery, mortality or tracheostomy in situ was higher in the PITS group than in the PTTS group (76.9% vs 63.6%, P = 0.043). Additionally, airway prosthesis removal was achieved in 46.2% of patients in the PITS group and in 33.0% of the PTTS group (P = 0.063).

CONCLUSION

There were significant differences between PITS and PTTS in terms of patient and stenosis characteristics, treatment modalities and clinical outcomes. Therefore, PITS and PTTS should be considered two different entities.

Fibrotic airway stenosis following radiotherapy in patients with adenoid cystic carcinoma

BACKGROUND AND OBJECTIVE

Radiotherapy is usually administered to the central airway in patients with unresectable adenoid cystic carcinoma (ACC). The purpose of this study was to describe the outcomes of endobronchial intervention in patients with airway stenosis following radiotherapy for ACC. Moreover, we investigated the incidence and contributing factors for airway stenosis following radiotherapy for ACC.

METHODS

Forty-seven patients with ACC, who underwent radiotherapy of the tracheobronchial tree from January 1995 to December 2011, were reviewed retrospectively. Fibrotic airway stenoses were diagnosed using three-dimensional computed tomography, flexible bronchoscopy or both.

RESULTS

Eleven (23%) of the 47 patients with ACC suffered fibrotic airway stenosis following radiotherapy and received bronchoscopic intervention. The median interval from radiotherapy to diagnosis of fibrotic airway stenosis was 7 months. Low forced expiratory volume in 1 s (FEV1), FEV1 /forced vital capacity and brachytherapy were verified as factors contributing to radiotherapy-induced airway stenosis. Bronchoscopic intervention provided both symptomatic relief and improvement of lung function, and no procedure-related death or major complication was observed. Insertion of a straight silicone stent was required in 10 patients (91%), and 4 (36%) eventually received Y-shaped silicone stents. The stents, once implanted, could not be removed in any of the patients; stents were well-tolerated for a prolonged period in all patients.

CONCLUSIONS

Fibrotic airway stenosis following radiotherapy in patients with ACC is often found. Bronchoscopic intervention, including silicone airway stenting, was a safe and useful method for treating radiotherapy-induced fibrotic airway stenosis in patients with ACC.

Fully biodegradable airway stents using amino alcohol-based poly(ester amide) elastomers

Airway stents are often used to maintain patency of the tracheal and bronchial passages in patients suffering from central airway obstruction caused by malignant tumors, scarring, and injury. Like most conventional medical implants, they are designed to perform their functions for a limited period of time, after which surgical removal is often required. Two primary types of airway stents are in general use, metal mesh devices and elastomeric tubes; both are constructed using permanent materials, and must be removed when no longer needed, leading to potential complications. This paper describes the development of process technologies for bioresorbable prototype elastomeric airway stents that would dissolve completely after a predetermined period of time or by an enzymatic triggering mechanism. These airway stents are constructed from biodegradable elastomers with high mechanical strength, flexibility and optical transparency. This work combines microfabrication technology with bioresorbable polymers, with the ultimate goal of a fully biodegradable airway stent ultimately capable of improving patient safety and treatment outcomes.

Tracheal wall thickening is associated with the granulation tissue formation around silicone stents in patients with post-tuberculosis tracheal stenosis

PURPOSE

Tracheal restenosis due to excessive granulation tissue around a silicone stent requires repeated bronchoscopic interventions in patients with post-tuberculosis tracheal stenosis (PTTS). The current study was conducted to identify the risk factors for granulation tissue formation after silicone stenting in PTTS patients.

MATERIALS AND METHODS

A retrospective study was conducted between January 1998 and December 2010. Forty-two PTTS patients with silicone stenting were selected. Clinical and radiological variables were retrospectively collected and analyzed.

RESULTS

Tracheal restenosis due to granulation tissue formation were found in 20 patients (47.6%), and repeated bronchoscopic interventions were conducted. In multivariate analysis, tracheal wall thickness, measured on axial computed tomography scan, was independently associated with granulation tissue formation after silicone stenting. Furthermore, the degree of tracheal wall thickness was well correlated with the degree of granulation tissue formation.

CONCLUSION

Tracheal wall thickening was associated with granulation tissue formation around silicone stents in patients with post-tuberculosis tracheal stenosis.

Long-term tolerance of airway silicone stent in patients with post-tuberculosis tracheobronchial stenosis

Surgery is a well-recognized modality of treatment for benign tracheobronchial stenosis. However, in some benign disease groups, such as tuberculosis, sarcoidosis, war gas exposure, and inhalation burns, multiplicity of involvement or long length of stenosed segment heightens surgical challenge. We investigated the outcomes and long-term tolerability of the Natural stent (N-stent) in such patients with post-tuberculosis tracheobronchial stenosis. A retrospective review was done for 17 patients who underwent silicone stenting (N-stent) for post-tuberculosis tracheobronchial stenosis during January 2000-December 2003 but needed persistent stent placement and still require the stent. Significant increase in the ratio of forced expiratory volume in 1 second (FEV1) to forced vital capacity (FVC), expressed as FEV1%, as well as in forced percentual vital capacity (FVC%) (Δ24% and Δ11%, respectively) in the short term and sustained increase in the FEV1% and FVC% (Δ26.5% and Δ16.5%, respectively) in the long term were noted at a median (range) interval of 1 (0.5-72) month and 72 (12-114) months, respectively, along with symptomatic relief. No procedure-related death occurred. Stent-related late complications included granulation tissue formation (76%), migration (70%), and mucostasis (17%). The median duration for which N-stents were tolerated was 7.9 (range, 3-11) years. N-stents are well-tolerated for a prolonged period. Stent-related complications occur, but are easily managed. These results might carry medical implications for those who have airway lesions difficult to correct surgically.

Results of interventional bronchoscopy in the management of postoperative tracheobronchial stenosis

OBJECTIVES

To investigate the role of bronchoscopic intervention in the management of postoperative tracheobronchial stenosis, a retrospective study was performed at a tertiary referral hospital.

METHODS

Thirty patients who underwent 106 bronchoscopic interventions between January 2000 and July 2010, including ballooning, bouginage, Nd:YAG laser resection, and stent insertion, were included and followed up for a median of 34 months.

RESULTS

Silicone stents were required in 19 of 30 patients (63%) to maintain airway patency. Bronchoscopic intervention provided improvement of dyspnea in 97% of the patients. After airway stabilization, the stents were removed successfully in 7 of 19 patients (37%) a median of 7 months after insertion. In 3 patients (10%), the intervention failed to widen the airway. There were no procedure-related deaths or cases of pneumonia, although additional interventions were needed in 9 patients (30%) within 30 days. Stent-related late complications (70%), such as restenosis (43%), overgrowth of granulation tissue (33%), stent migration (32%), mucostasis (30%), and malacia after stent removal (16%), were controllable at follow-up bronchoscopy.

CONCLUSIONS

Bronchoscopic intervention could be a useful treatment modality for patients with postoperative tracheobronchial stenosis when surgery is not feasible.

Prognostic factors for endotracheal silicone stenting in the management of inoperable post-intubation tracheal stenosis

PURPOSE

Stenting has been developed to deal with airway stenosis and is applicable in patients with post-intubation tracheal stenosis (PITS) in whom surgery would not be indicated. The purpose of this study was to investigate the prognostic factors in inoperable patients in whom a silicone stent was inserted due to PITS.

MATERIALS AND METHODS

We retrospectively evaluated 55 PITS patients undergoing silicone stenting between January 2001 and December 2009.

RESULTS

Silicone stent was inserted to narrowed trachea after the combination of pre-dilatation including laser cauterization, mechanical bougienation and ballooning. Following airway stabilization, the stent could be removed successfully in 40% (22/55) of the patients after median 12 months of stenting. However, in 60% (33/55) of patients, the stent could not be removed successfully and surgical management was needed after initial stabilization. Multivariate analysis revealed that the stent could be successfully removed more frequently in those who do not have cardiovascular disease [odds ratio (OR)=12.195; p=0.036] and the intervention was performed within 6 months after intubation (OR=13.029; p=0.031).

CONCLUSION

Among those patients undergoing silicone stenting due to PITS, the stent could be successfully removed when patients do not have cardiovascular disease and stented within 6 months after intubation.

Posttuberculosis tracheobronchial stenosis: use of CT to optimize the time of silicone stent removal

PURPOSE

To evaluate whether air pockets (tracheobronchial air columns in the space between the outer surface of the stent and the adjacent airway wall) discernible at computed tomography (CT) can help optimize the time of stent removal in patients with posttuberculosis tracheobronchial stenosis (PTTS).

MATERIALS AND METHODS

The study was approved by the institutional review board, and informed consent was obtained from all patients. Data from 41 patients (five men, 36 women) with a median age of 39 years (range, 21-64 years) who underwent silicone stent placement owing to PTTS, followed by CT and stent removal 6-12 months after clinical stabilization, were investigated retrospectively. Two radiologists determined whether the extent of air pockets on CT scans was associated with clinical success, which was defined as maintenance of a prosthesis-free airway for more than 2 years after stent removal. Radiologic features were compared for outcome by using a Wilcoxon two-sample test or Fisher exact test.

RESULTS

Stents were removed successfully in 31 patients (76%). Air pockets longer than 1 cm or longer than 2 cm were associated with successful stent removal (P = .04 and P = .006, respectively). The sensitivity and specificity of air pocket length in the prediction of successful stent removal were 84% and 50%, respectively, for air pockets longer than 1 cm and 68% and 70% for air pockets longer than 2 cm.

CONCLUSION

The extent of air pockets at chest CT shows correlation with the success of stent removal, indicates regression of stenosis, and may help guide the optimal time for stent removal.

Factors predicting outcome following airway stenting for post-tuberculosis tracheobronchial stenosis

BACKGROUND AND OBJECTIVE

Silicone airway stents are used to widen narrowed airways in patients with post-tuberculosis tracheobronchial stenosis (PTTS). After mechanical stabilization, stents can be removed from the majority of patients leaving restored airway patency. However, in a significant minority re-stenosis develops post-sten removal thus necessitating surgical intervention or long-term stenting. In this study, we sought to establish prognostic factors for successful airway intervention in PTTS.

METHODS

We retrospectively investigated 71 patients who underwent silicone stenting due to PTTS. After stenting, bronchoscopic toileting and/or repositioning was performed during follow up. At 6-12 months after clinical stabilization, stents were planned to be removed. Patients with patent airways were followed if no further intervention was required. If restenosis developed, patients underwent re-stenting or operation. Clinical parameters were analysed to determine favourable prognostic factors.

RESULTS

Stents were successfully removed in 40 patients at a median 12.5 months after insertion. In 27 patients, stent re-insertion was carried out and four patients underwent surgical management. Multivariate logistic regression analysis revealed that successful stent removal was independently associated with atelectasis <1 month before bronchoscopic intervention, and absence of complete lobar atelectasis.

CONCLUSIONS

Airway intervention, including silicone stenting, can be successful in patients with PTTS, when the intervention is performed within 1 month of atelectasis and before complete lobar atelectasis.

Treatment outcomes of patients with adenoid cystic carcinoma of the airway

BACKGROUND

Adenoid cystic carcinoma (ACC) of the airway is a slowly growing tumor and airway narrowing is one of the main causes of death. The purposes of this study were to investigate treatment outcomes, prognostic factors, and the indications and outcomes of bronchoscopic interventions in patients with ACC of the airway.

METHODS

We retrospectively analyzed the clinical characteristics, treatment modalities, and clinical outcomes of patients with histologically-proven ACC of the airway treated between January 1995 and June 2009 at Samsung Medical Center.

RESULTS

A total of 30 patients were included in the study. Sixteen patients were male and the median age was 45 years. Multiple treatment modalities were required for the patients; 17 for surgery, 13 for definitive radiation therapy, 10 for adjuvant radiation therapy, and 1 for adjuvant chemotherapy. Bronchoscopic interventions were required to improve airway narrowing in 20 patients. After bronchoscopic intervention, 19 patients (95%) showed immediate improvement of airway narrowing and suffered no serious complications. The 5- and 10-year overall survival (OS) rates in these patients were 84% and 70%, respectively. The prognostic factors associated with OS were tumor size, tumor location, clinical T stage, surgery as an initial treatment, and bronchoscopic intervention.

CONCLUSIONS

ACC of the airway had a good long-term prognosis but bronchoscopic interventions were frequently required during the course of the disease due to the development of airway narrowing. Bronchoscopic interventions may be considered as a bridge therapy before surgery or radiation therapy and as a palliative therapy for airway narrowing.

Emergent management of malignancy-related acute airway obstruction

Acute obstruction of the airway in the emergent situation results from a wide variety of malignant and benign disease processes. Acute management involves establishing a secure and patent route for adequate gas exchange. This requires rapid determination of the location of the obstruction and nature of the obstruction followed by a thoughtful management approach based on findings. Difficult anatomy, hemorrhage, dense secretions, inflammation, and bulky tumor mass can significantly complicate the task of clearing the airway. Obstruction of the central airways by malignant tumor is associated with poor prognosis, but quality of life is considerably improved by restoration of adequate central airways. For both the patient and the clinician, the presentation can be frightening, and advanced interventional pulmonary/endobronchial techniques are required to achieve prompt relief of symptoms. The alleviation of central airway obstruction by tumor is most often palliative, with improvement of quality of life the primary goal rather than cure. This review will cover covers an approach to the patient with airway obstruction that results from malignancy involving the trachea or proximal bronchial tree and affecting gas exchange.

Desenvolvimento de uma órtese de Dumon modificada para aplicações traqueais: um estudo experimental em cães

OBJETIVO: Descrever o desenvolvimento de uma órtese de silicone e os testes in vivo de compatibilidade e aplicabilidade na traquéia canina normal. MÉTODOS: Quatro densidades de silicone foram testadas para a obtenção de protótipos. Para cada densidade, foi calculada a pressão exigida para causar a compressão, considerando-se uma área de contato de 1 cm² e uma redução de 30% no diâmetro. A densidade selecionada foi 70-75 Shore A hardness. Adicionou-se sulfato de bário em pó ao silicone para tornar a órtese desenvolvida radiopaca e facilmente identificável ao exame radiológico. A órtese desenvolvida apresenta superfície externa corrugada com arcos salientes e descontínuos, semelhantes aos anéis traqueobrônquicos, para intercalação e fixação nas vias aéreas inferiores, superfície interna polida e extremidades lisas que evitam o dano por fricção. O protótipo considerado como sendo o mais adequado em termos de rigidez e flexibilidade foi implantado broncoscopicamente em traquéias caninas normais. Os animais foram sacrificados após oito semanas, e a traquéia foi removida para análise anatomopatológica. RESULTADOS: Não houve complicações após a implantação das órteses. Nenhuma precisou ser removida, e todas estavam bem posicionadas ao final de oito semanas. O estudo histopatológico mostrou que a membrana basal epitelial foi preservada. Foram observados pontos focais de desnudamento epitelial, leve infiltrado inflamatório sob a mucosa e, mais raramente, tecido de granulação com neoformação vascular e ausência de microorganismos. CONCLUSÕES: A órtese desenvolvida mostrou resistência aos esforços mecânicos e biocompatibilidade, não provocando reação tecidual adversa na traquéia canina, além de permanecer íntegra ao final do experimento.

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.

A decade of using intraluminal tracheal/bronchial stents in the management of tracheomalacia and/or bronchomalacia: is it better than aortopexy?

BACKGROUND

We compared the efficacy and clinical outcomes of aortopexy versus tracheal stents in the management of tracheomalacia.

METHODS

A retrospective analysis of 25 consecutive patients undergoing aortopexy (n = 11; 8 boys, 3 girls) or tracheal stents (n = 14; 9 boys, 5 girls) between 1993 and 2003 was performed.

RESULTS

Both treatment groups, aortopexy versus stents, were comparable in their mean age of diagnosis, timing of intervention, surgical indications ("dying spell" or failed extubation), and previous underlying conditions. The operative time (190 vs 72 minutes) and blood loss (26 vs 0 mL) were significantly greater in aortopexy group (P < .01). There were no perioperative deaths in either group. Interestingly, 4 of 11 patients in the aortopexy group developed pericardial effusion (P < .01). With stents in place for a mean of 15 (range 2-41) months, 3 of 8 patients with stent removal had significant granulation tissue requiring further dilatation. No death was observed in aortopexy group, whereas 1 stent-related death and 1 cardiac arrest requiring median sternotomy occurred during stent removal in 44 and 32 months' follow-up, respectively.

CONCLUSION

Both aortopexy and tracheal stents are effective treatment modalities in the management of tracheomalacia. However, although aortopexy is associated with early perioperative complications, tracheal stents are associated with higher failure rate and more severe stent-related morbidity and mortality.

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.

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.

Metallic tracheal stents: complications associated with long-term use in the upper airway

The use of metallic airway stents for the treatment of benign airway stenosis is increasingly advocated; however, the long-term safety and efficacy of these devices has not been established. Three case studies involving late but significant proximal tracheal stent complications are reported: 1 related to proximal mechanical stent failure and 2 related to obstructing granulation tissue and stenosis at the proximal stent orifice. Placement of these stents in close proximity to the cricotracheal junction is thought to be primarily responsible for these complications as a result of the excess shearing forces created at the stent-mucosal interface by the differential motion of the stent relative to the rigid subglottic airway and the more distensible trachea. Although the use of metallic stents remains appropriate in cases in which there is a defined and relatively short-term end point for treatment, caution is urged in using them in the proximal trachea for long-term management of benign airway disease.

Therapeutic bronchoscopy in lung cancer. Laser therapy, electrocautery, brachytherapy, stents, and photodynamic therapy

Therapeutic bronchoscopic techniques such as LPR, EC, brachytherapy, stents, and PDT are effective tools in the palliation and local control of lung cancer. Palliation of malignant tracheobronchial obstruction by LPR, stents, brachytherapy, PDT, or a combination thereof results in relief of dyspnea, hemoptysis, and postobstructive pneumonia. Importantly, it avoids intubation in patients with respiratory distress and facilitates the weaning of patients from MV. In the exciting field of lung cancer screening and treatment of early lung cancer, PDT, brachytherapy, EC, and LPR may represent treatment alternatives to surgical resection, especially in a select group of patients with high surgical risk or favorable endobronchial lesions. Clinicians await the results of future studies, which will (1) better define the impact of each treatment modality on patient care in terms of cost, survival, and improvement in quality of life, and (2) determine the optimal combination therapy relative to bronchoscopic and conventional treatment for effective palliation and cure of lung cancer.

Multidisciplinary airway stent team: a comprehensive approach and protocol for tracheobronchial stent treatment

Tracheobronchial stents are being used with increasing frequency to treat major airway obstruction from both malignant and benign processes. Traditionally, stents have been placed via rigid bronchoscopy, flexible bronchoscopy, or fluoroscopy by members of various individual disciplines. We describe a novel multidisciplinary airway stent team (MAST) protocol for tracheobronchial stent placement and endoscopic management of major airway obstruction. A patient with symptoms of airway obstruction is generally first evaluated with a computed tomography scan and a videotaped flexible bronchoscopy. These studies are reviewed by the team otolaryngologist, pulmonologist, and interventional radiologist. A treatment plan, including the type and location of stents and the need for adjuvant therapies, is formulated. Stent placement is performed in the operating room under general anesthesia. Rigid bronchoscopy, with flexible bronchoscopy and fluoroscopy as needed, allows precise stent placement and the best use of various therapeutic methods. The MAST protocol combines the skills, knowledge, and unique therapeutic options of specialists from otolaryngology, pulmonology, and interventional radiology. This approach allows optimal stent placement and the use of other endobronchial therapies, including laser ablation, balloon dilation, photodynamic therapy, cryotherapy, and brachytherapy. A protocol with representative case reports is presented, along with a review and comparison of several of our most commonly used stents. Otolaryngologists who practice bronchoesophagoscopy, by virtue of their operative skill and knowledge of airway management, are well equipped to become leaders of MASTs and are encouraged to initiate MASTs at their institutions.

Surgical palliation of airway obstruction resulting from lung cancer

Bronchogenic carcinoma remains a relentless plague of modern society causing far more deaths than the well-popularized "AIDS epidemic" and secondary only to cardiovascular disease as a cause of death in America. Despite medical advances and treatment breakthroughs, only 40% of newly identified lung cancer patients are "potentially curable". Therefore, a large portion of this patient population will require palliative care and treatment. Surgical palliation is somewhat a misnomer in that most endobrachial lesions causing significant obstruction that result in dyspnea are not amenable to surgical intervention, i.e., operative resectional therapy. The palliative management options of airway obstruction resulting from advanced stage lung cancer will be reviewed, including the historical aspects, development and current use of laser resection, airway stenting, and endobrachial brachytherapy for management of unresectable airway tumors. These modalities frequently are used simultaneously in the same patient and may be used in conjunction with current chemotherapeutic and conventional external-beam radiation protocols.

Stenting of the tracheobronchial tree

Endoscopic treatment of endobronchial obstructions is becoming increasingly important. Tracheobronchial stents often are needed in the treatment of obstructions from submucosal or extrabronchial lesions. Tube stents have been available since the early 1960s but are underused because their insertion requires the use of a rigid bronchoscope. With the recent development of metallic stents, interventional radiologists increasingly are involved in the treatment of tracheobronchial obstructions. Metallic stents, easily placed with flexible bronchoscopy, are growing in popularity. All available tracheobronchial stents have been shown in various clinical series to be able to achieve immediate resolution of respiratory symptoms from various tracheobronchial obstructions. A stent's performance, however, should not be based solely on short-term response. Presently, there is no ideal stent because none is free of complications and none are able to consistently maintain life-long patency. Gianturco stents are associated with serious major complications (bronchial perforations and strut fractures) and are no longer recommended for use in the tracheobronchial tree. The Palmaz stent has also fallen into disfavor, because a strong external force, such as a vigorous cough, can recompress it. The Strecker stent can only be used in smaller airways, but may be useful in the accurate stenting of short segment stenoses because it does not foreshorten on deployment. The Wallstent and Ultraflex are our present metallic stents of choice. Both are easy to deploy, available in covered forms, exert adequate radial force, remain relatively stable in position, and have good longitudinal flexibility for use in tortuous airways. Disadvantages include excessive granulation tissue formation and difficulty of removal once the stent has been epithelialized. Metallic stents should be chosen very carefully for use in benign lesions with ongoing active local inflammation or when temporary stenting is needed. In the absence of an ideal stent, technologic advancements will continue. Potential developments include removable metallic stents, biodegradable stents, and chemically and radioactively coated stents. Unquestionably, the expanding stent market will drive scientific research toward the development of the ideal stent. Clearly, physicians need to be ready to assess these technologic advancements.

Bronchoscopic management of central airway obstruction

OBJECTIVES

Patients with central airway obstruction are critically ill, with impending suffocation. They are seen with diverse anatomic and functional deficits caused by both benign and malignant obstructions. Such cases were reviewed to examine the indications, techniques, and outcomes of an algorithm approach to bronchoscopic management.

METHODS

Between July 1992 and April 1996, 97 patients underwent bronchoscopic procedures for the management of central airway obstruction, and their cases were used for a retrospective review of the airway management.

RESULTS

There were 48 male and 49 female patients, aged 13 to 85 years. There were 48 benign and 49 malignant pathologic conditions that gave rise to 108 stenoses. These were treated with 199 endoscopic procedures with an average of 1.7 interventions per endoscopy, including mechanical core-out (62), dilation (135), laser ablation (44), placement of brachytherapy catheters (9), and stent placement (88). Diagnoses included lung cancer, primary tracheobronchial tumors, tumors metastatic to the airway or mediastinum, and a variety of benign obstructions. In the group of 97 patients there were 2 (2%) perioperative deaths and 34 (34%) late deaths, 29 in the malignant group and 5 in the benign group. Median survival was 7.6 months (range 1 week-31 months). There were 7 (7%) complications among the group of 97, 4 in the malignant group, and 3 in the benign group.

CONCLUSIONS

Endobronchial surgical techniques can be used safely and systematically for the relief of benign and malignant central airway obstructions; a diversity of approaches and interventions are required to produce and maintain palliation of airway symptoms.

Fiberoptic bronchoscopy for diagnosis and treatment

Bedside fiberoptic bronchoscopy is a valuable tool in the diagnosis and treatment of various respiratory conditions in critically ill patients. The fiberoptic bronchoscope allows direct airway inspection, facilitating the diagnosis of benign and malignant airway lesions. In addition, pulmonary secretions or tissue samples can be collected using the bronchoscope and techniques that allow sampling of the lower airways with minimal or no upper airway contamination. Collection of lower airway samples is important in the diagnosis of pulmonary infiltrates in immunocompromised patients, in many patients with ventilator-associated pneumonia, and in selected patients with CAP. The fiberoptic bronchoscope can be used for therapeutic interventions, such as insertion of an endotracheal tube, removal of an aspirated foreign body, clearance of tenacious secretions, promotion of hemostasis in patients with hemoptysis, instillation of drugs, and assistance in the placement of tracheobronchial prostheses (i.e., airway stents). If proper preprocedural training and planning are done and the patient is monitored carefully during the procedure, fiberoptic bronchoscopy can be performed quickly and safely at the bedside in most critically ill patients.

Palliative treatment for tracheal stenoses using carbon dioxide laser and the Gianturco stent. Long-term results

Between September 1992 and March 1998, the self-expandable Gianturco prosthesis was inserted in 23 patients suffering from tracheal stenosis. After radial incision and dilation of the stenosis as described by Shapshay, the positioning of the stent was performed during an endoscopic procedure under optical control. The prosthesis used was a double-ring stent 50 mm long and 20 mm in diameter. The follow-up period ranged between 0.5 and 67 months with an average of 31 +/- 18 months. Pulmonary function tests showed an average improvement of the peak expiratory flow (50%) from preoperative results of 1.06 +/- 0.60 L/s to short-term postoperative results of 2.08 +/- 0.78 L/s and long-term postoperative results of 2.11 +/- 0.78 L/s. The mean peak inspiratory flow (50%) improved from 1.43 +/- 0.85 L/s to 2.40 +/- 1.29 L/s at short term and to 2.56 +/- 1.20 L/s at long term. Eight patients out of the 23 had to undergo a second endoscopic procedure: 3 patients for granuloma vaporization; 1 patient to change a malpositioned stent; 2 patients to add a second stent because of insufficient tracheal enlargement; and 2 patients to resect mucosal membranes between the 2 stent rings and to place a second stent. Optical control of the accurate positioning and use of this model of Gianturco prosthesis helped to avoid the severe complications described in the literature (migration, extrusion, fracture, wall erosion. and hemorrhage). The follow-up must particularly target the prevention of granulomas. The self-expandable Gianturco prosthesis can be advocated for long-term palliative treatment of tracheal stenoses that are inoperable by an external surgical approach.

Bilevel non-invasive ventilation in malignant large airways obstruction during chemotherapy and radiotherapy

A case is described of acute respiratory failure secondary to variable intrathoracic large airway obstruction due to a lung neoplasm. Successful ventilation was achieved with facemask bilevel non-invasive ventilatory assistance allowing radiotherapy and chemotherapy to be undertaken.

Delayed massive hemoptysis after expandable bronchial stent placement

Patients with lung cancer often develop airway obstruction that necessitates palliative bronchoscopic interventions. Expandable metal stents are increasingly used for this indication. We report a case of fatal massive hemoptysis that occurred 1 week after uneventful bronchial stent placement. Previous treatment with external-beam radiotherapy, brachytherapy, and photodynamic therapy probably contributed to pulmonary artery-bronchial fistulization in this patient. This complication should be kept in mind when considering expandable airway stent insertion in heavily pretreated lung cancer patients.

Future of flexible bronchoscopy

Despite some potential "threats" (Table 3), the future of bronchoscopy is likely full with ever expanding applications in clinical medicine and research (Tables 1 and 2). The role of bronchoscopy in lung cancer continues to expand and the usefulness of newer techniques needs to be established. The role of FB is also ever expanding in the immuno compromised host and critically ill patients. Future studies, however, should concentrate on patient outcome, especially survival and performance status. Therapeutic bronchoscopy has been extended to many areas and the emphasis of future research will likely continue to be at the molecular level rather than on studies of better instruments for retrieval purposes. The most exciting developments are likely to be in the field of gene therapy, which has made remarkable progress in the past decade. Gene therapy can be a powerful technology, but several hurdles must be overcome to make gene therapy a reality for treating human disease in the future. As the cost of technology continues to challenge health care delivery systems, a major challenge for the future of bronchoscopy is to evaluate new technologies and applications based on their impact on patient outcome, survival, and management of cost.

Airway stents

Considerable progress has been made since the initial stents were manufactured. Despite the reported side effects, cumulative evidence suggests beneficial effects in properly selected patients. The technology is still in evolution, and design modifications strive to find the perfect stent. The Dumon stent remains the gold standard against which the functions of all other stents are being measured. Unfortunately requirement for the RB for deployment has restricted widespread application at least in the United States. The Wallstent can be inserted using FB and has a great potential among the metal stents. Its biggest drawback is that once inserted it is difficult to remove. Studies with the nitinol Ultraflex and the polyester/silicone Polyflex prototype stent also show promise, although extensive experience and long-term follow-up data are still not available. It is possible that combining the strength of the tube stents with the flexibility of the metal stents may one day help to develop the ideal stent.

Airway stenting in Japan

Various types of outstanding airway stents have been made commercially available. In Japan, a total of 1004 airway stents (Dumon stents (Novatech, Aubagne, France), Gianturco Z stents (Cook Ins, Bloomington, USA), Ultraflex stents (Boston Scientific Corp, Natick, MA, USA), and Dynamic Y stents (Ruesch AG, Kernen, Germany)) were implanted from July 1991 until February 1998. Of all the various stents, the Dumon stent has become the standard worldwide. Also, the Dumon stent has been replacing the Gianturco Z stent as the preferred stent throughout Japan. The Dumon stent was the first stent covered by Japanese National Health Insurance. Therefore, we present our 5-year experience with the Dumon stent at our institution. In our experience, stenting is effective for the immediate and lasting relief of symptoms in patients with severe malignant obstruction of major airways.

Stenting therapy for stenosing airway disease

Stenosing airway disease is classified as intraluminal obstruction, extrinsic compression, and malacia by the anatomical site of the lesion. Stenting therapy is indicated for symptomatic relief of life-threatening dyspnea caused by the last two types. Airway stents are made with metal mesh and/or silicone rubber, and currently more than 20 kinds of stent are available. The metal stent (e.g. Gianturco stent, Wallstent) is easy to insert, may not need general anesthesia, and has wider internal lumen. Because it is very hard to reposition or remove, it is mainly used in malignant airway obstruction. Among many kinds of silicone stent, the Dumon stent is most widely used for benign and malignant airway stenoses, but general anesthesia and rigid bronchoscopy are needed for insertion. It can be removed when the stenosing airway disease subsides completely. In many clinical studies, most patients (85-90%) improved immediately after stenting, and procedure-related mortality is low (< 3%) in experienced centers. Stent displacement, mucus impaction, and granulation tissue formation are potential complications. Stenting is one of many effective therapeutic modalities for stenosing central airway disease. Careful patient selection, experiences, and continuous development of new technology will bring better results.