Interventional bronchoscopy for the management of airway complications following lung transplantation

Lung transplant airway complications treated with biodegradable airway stents: The Dutch multi-center experience

INTRODUCTION

Treatment of post lung-transplant airway complications is challenging, and treatment with conventional airway stents is associated with adverse events. More recently, biodegradable airway stents (BDS) have been introduced and may be used to reduce these adverse events. In this study we explore the feasibility of treatment with BDS post lung transplant.

METHODS

All patients treated with BDS in The Netherlands were included in this retrospective multicenter study. Feasibility, life span of the stent, occurrence of adverse events, and evolution of lung function were evaluated.

RESULTS

Twelve patients (six malacia and six stenosis) received a total of 57 BDS, ranging from 1 to 10 BDS per patient. Six patients had been pretreated with conventional airway stents. Median stent life span was 112 days (range 66-202). No adverse events occurred during stent placement. In 5 out of 57 stent placements, a single additional bronchoscopy was necessary because of mucus accumulation (n = 4) or excessive granulation tissue (n = 1). All stent naïve patients became airway stent independent after treatment; all patients pretreated with conventional airway stents were still airway stent dependent at the end of follow up.

CONCLUSION

Treatment with BDS is safe and feasible. Adverse events were mild and easily treatable. All patients with initial treatment with BDS were airway stent independent at the end of follow up with a median treatment of 4 BDS.

Tracheobronchial stents: an expanding prospect

The first dedicated tracheobronchial silicone stent was designed by the French pulmonologist Jean-Paul Dumon. The most common indications for stenting are to minimise extrinsic airway compression from mass effect, maintain airway patency due to intrinsic obstruction or treat significant nonmalignant airway narrowing or fistulae. Silicone stents require rigid bronchoscopy for insertion; however, they are more readily repositioned and removed compared with metallic stents. Metallic stents demonstrate luminal narrowing when loads are applied to their ends, therefore stents should either be reinforced at the ends or exceed the area of stenosis by a minimum of 5 mm. Nitinol, a nickel-titanium metal alloy, is currently the preferred material used for airway stents. Airway stenting provides effective palliation for patients with severe symptomatic obstruction. Drug-eluting and three-dimensional printing of airway stents present promising solutions to the challenges of the physical and anatomical constraints of the tracheobronchial tree. Biodegradable stents could also be a solution for the treatment of nonmalignant airway obstruction.

Three Decades Single Center Experience of Airway Complications After Lung Transplantation

Post lung transplantation airway complications like necrosis, stenosis, malacia and dehiscence cause significant morbidity, and are most likely caused by post-operative hypo perfusion of the anastomosis. Treatment can be challenging, and airway stent placement can be necessary in severe cases. Risk factors for development of airway complications vary between studies. In this single center retrospective cohort study, all lung transplant recipients between November 1990 and September 2020 were analyzed and clinically relevant airway complications of the anastomosis or distal airways were identified and scored according to the ISHLT grading system. We studied potential risk factors for development of airway complications and evaluated the impact on survival. The treatment modalities were described. In 651 patients with 1,191 airway anastomoses, 63 patients developed 76 clinically relevant airway complications of the airway anastomoses or distal airways leading to an incidence of 6.4% of all anastomoses, mainly consisting of airway stenosis (67%). Development of airway complications significantly affects median survival in post lung transplant patients compared to patients without airway complication (101 months versus 136 months, p = 0.044). No significant risk factors for development of airway complication could be identified. Previously described risk factors could not be confirmed. Airway stents were required in 55% of the affected patients. Median survival is impaired by airway complications after lung transplantation. In our cohort, no significant risk factors for the development of airway complications could be identified.

[Interventionnal bronchoscopy for the treatment of tracheobronchomalacia]

Tracheobronchomalacia is usually characterized by more than 50% expiratory narrowing in diameter of the trachea and the bronchi. The expiratory collapse includes two entities: (1) the TBM related to the weakness of the cartilaginous rings, and (2) the Excessive Dynamic Airway Collapse (EDAC) due to the excessive bulging of the posterior membrane. Patients have nonspecific respiratory symptoms like dyspnea and cough. Diagnosis is confirmed by dynamic tests: flexible bronchoscopy and/or computed tomographic scan of the chest. There are different forms of tracheobronchomalacia in adults: primary (genetic, idiopathic) or secondary to trauma, tracheotomy, intubation, surgery, transplantation, emphysema, infection, inflammation, chronic bronchitis, extrinsic compression; or undiagnosed in childhood vascular rings. Some management algorithms have been proposed, but no specific recommendation was established. Only symptomatic patients should be treated. Medical treatments and noninvasive positive pressure ventilation should be the first line therapy, after evaluation of various quality measures (functional status, performance status, dyspnea and quality of life scores). If symptoms persist, therapeutic bronchoscopy permits: (1) patient's selection by stent trial to determine whether patient benefit for surgical airway stabilization; (2) malacic airways stenting in patients who are not surgical candidates, improving QOL despite a high complication rate; (3) the management of stent-related complication (obstruction, plugging, migration granuloma); (4) alternative therapeutics like thermo-ablative solution. Lasty, the development of new types of stents would reduce the complication rates. These different options remained discussed.

Case report: Lung transplantation for treatment of paraquat intoxication: timing of transplantation

Objective: To analyze the optimal timing of lung transplantation and summarize postoperative complications and their management after paraquat poisoning. Methods: Here, we present the clinical course of a 17-year-old boy with paraquat poisoning, in whom bilateral lung transplantation (LT) was performed. We reviewed the eight previously published articles relevant to LT after paraquat poisoning to summarize the therapeutic strategy. Results: A 17-year-old boy was admitted to the hospital after ingestion of 30-50 mL 25% paraquat. Mechanical ventilation was initiated on the 25th day after intoxication. Venovenous extracorporeal membrane oxygenation was initiated on the 26th day. Sequential bilateral LT was performed on the 27th day. Several complex postoperative complications occurred and the patient was discharged on the 50th day postoperatively. Eight case reports were included in the literature review, including 11 patients with paraquat poisoning undergoing LT. Three patients died due to paraquat poisoning leading to fibrosis in the transplanted lungs or postoperative complications. Eight patients survived during follow-up. Conclusion: LT after herbicide poisoning should be planned when hepatorenal function starts to recover, and waiting for complete recovery is unnecessary. Prevention of infection before surgery is important to reduce the incidence of postoperative infection. Complex perioperative complications caused by the herbicide itself or the late timing of transplantation can be successfully managed by a multidisciplinary team.

Forbearance with endobronchial stenting: cognisance before conviction

Endobronchial stenting is an important aspect of the practice of interventional pulmonology. The most common indication for stenting is the management of clinically significant airway stenosis. The list of endobronchial stents available on the market continues to grow. More recently, patient-specific 3D-printed airway stents have been approved for use. Airway stenting should be considered only when all other options have been exhausted. Due to the environment of the airways and the stent-airway wall interactions, stent-related complications are common. Although stents can be placed in various clinical scenarios, they should only be placed in scenarios with proven clinical benefit. The unwarranted placement of a stent can expose the patient to complications with little or no clinical benefit. This article reviews and outlines the key principles of endobronchial stenting and important clinical scenarios in which stenting should be avoided.

Interventional pulmonology techniques in lung transplantation

Lung transplantation is a key therapeutic option for several end-stage lung diseases. Interventional pulmonology techniques, mostly bronchoscopy, play a key role throughout the whole path of lung transplantation, from donor evaluation to diagnosis and management of post-transplant complications. We carried out a non-systematic, narrative literature review aimed at describing the main indications, contraindications, performance characteristics and safety profile of interventional pulmonology techniques in the context of lung transplantation. We highlighted the role of bronchoscopy during donor evaluation and described the debated role of surveillance bronchoscopy (with bronchoalveolar lavage and transbronchial biopsy) to detect early rejection, infections and airways complications. The conventional (transbronchial forceps biopsy) and the new techniques (i.e. cryobiopsy, biopsy molecular assessment, probe-based confocal laser endomicroscopy) can detect and grade rejection. Several endoscopic techniques (e.g. balloon dilations, stent placement, ablative techniques) are employed in the management of airways complications (ischemia and necrosis, dehiscence, stenosis and malacia). First line pleural interventions (i.e. thoracentesis, chest tube insertion, indwelling pleural catheters) may be useful in the context of early and late pleural complications occurring after lung transplantation. High quality studies are advocated to define endoscopic standard protocols and thus help improving long-term prognostic outcomes of lung transplant recipients.

Utility and safety of airway stenting in airway stenosis after lung transplant: A systematic review

Background

Airway complications seriously affect the clinical outcomes and long-term prognosis of lung-transplantation patients. Airway stenting provides effective palliation for patients with airway stenosis. However, a lack of consensus regarding the efficacy and safety of airway stents in airway stenosis after lung transplantation. This study critically evaluated all available evidence regarding this concern.

Methods

We retrieved studies from EMBASE, PubMed, and Cochrane Library databases. Studies were included if they reported baseline characteristics of airway complications after lung transplantation, stenting for airway stenosis, or prognosis.

Results

In total, 279 papers were screened and 17 papers were included in final analysis. The short-term efficacy of airway stenting was assessed in almost all studies, with immediate palliation in symptom and improved pulmonary function reported. Eleven of the included studies evaluated the long-term efficacy of stent therapy, with no distinct lung function. The median overall survival time was 1,124 (95% confidence interval 415–1,833) days in stented patients only. Stent-related complications are common regardless of the material; However, serious complications are rare and can be improved with routine management.

Conclusion

We demonstrated that airway stenting is a safe and effective method to treat airway stenosis after lung transplantation. The short-term effect was significant, while the long-term efficacy on survival rate needed further investigations.

Systematic review registration

www.crd.york.ac.uk/prospero/, identifier: CRD42022364427.

Incidence, risk factors, and clinical characteristics of airway complications after lung transplantation

Airway complications may occur after lung transplantation and are associated with considerable morbidity and mortality. We investigated the incidence, risk factors, and clinical characteristics of these complications. We retrospectively reviewed the medical records of 137 patients who underwent lung transplantation between 2008 and 2021. The median follow-up period was 20 months. Of the 137 patients, 30 (21.9%) had postoperative airway complications, of which 2 had two different types of airway complications. The most common airway complication was bronchial stenosis, affecting 23 patients (16.8%). Multivariable Cox analysis revealed that a recipient's body mass index ≥ 25 kg/m² (hazard ratio [HR], 2.663; p = 0.013) was a significant independent risk factor for airway complications, as was postoperative treatment with extracorporeal membrane oxygenation (ECMO; HR, 3.340; p = 0.034). Of the 30 patients who had airway complications, 21 (70.0%) were treated with bronchoscopic intervention. Survival rates did not differ significantly between patients with and without airway complications. Thus, our study revealed that one fifth of patients who underwent lung transplantation experienced airway complications during the follow-up period. Obesity and receiving postoperative ECMO are risk factors for airway complications, and close monitoring is warranted in such cases.

Safety of hybrid bronchial stents in transplant airway complications: a single center experience

Background

Tracheobronchial stents are often used to manage lung transplant airway complications. In 2005, the Food and Drug Administration (FDA) issued a warning against the use of metallic stents for benign airway disease. Since that time, fully covered hybrid metallic stents have been developed and are increasingly used due to their ease of insertion and removal. There is limited data to support their safe utilization for transplant airway complications. This is the largest analysis to date of the safety of hybrid metallic stents for transplant airway complications.

Methods

We performed a retrospective study of patients who had covered metallic stents placed for transplant airway complications between April 2016 to April 2021. Information obtained from chart review included demographics, procedure notes and stent data including indication for placement, type, size, location, duration, and complications.

Results

We identified 50 patients who had a combined 376 stents placed for a total of 15,711 stent days. The most common minor complication and reason for removal was mucus plugging affecting 193 stents.There were only two cases of major stent associated complications. Among minor complications, there was a increased risk of stent fracture with Bonastent^® (P=0.04).

Conclusions

Our data shows that hybrid metallic stents are a safe intervention for patients with transplant airway complications. Most complications were minor and managed with repeat bronchoscopy. There were only two major complications over a 5-year period. Given the wide spectrum of possible airway complications, further research is needed to determine the optimal use of stents for patients with transplant airway complications.

Airway complications in lung transplantation

Airway complications (ACs) after lung transplantation remain an important source of morbidity and mortality despite significant advances in the surgical technics, leading to increased cost, and decrease quality of life. The incidences of ACs after lung transplantation range from 2% to 33%, even though most transplant centers have reported rates in the range of 7% to 8%. However, the reported rate of ACs has been inconsistent as a result of a lack of standardized airway definitions and grading protocols before the recent 2018 International Society for Heart and Lung Transplantation (ISHLT) proposed consensus guidelines on ACs after lung transplantation. The ACs include stenosis, perioperative and postoperative bronchial infections, bronchial necrosis and dehiscence, excess granulation tissue, and tracheobronchomalacia (TBM). Anastomosis infection, necrosis, or dehiscence typically develops within the first month after lung transplantation. The most frequent AC after lung transplantation is bronchial stenosis. Several risk factors have been proposed to the development of ACs after lung transplantation, including surgical anastomosis techniques, hypoperfusion, infections, donor and recipient factors, immunosuppression agents, and organ preservation. ACs might be prevented by early recognition of the airway pathology, using advance medical management, and interventional bronchoscopy procedures. Balloon bronchoplasty, cryotherapy, laser photo resection, electrocautery, high-dose endobronchial brachytherapy, and bronchial stents placement are the most frequent interventional bronchoscopic procedures utilized for the management of ACs.

[Endoscopic treatment of bronchial complications after lung transplantation]

OBJECTIVE

To analyze the incidence and structure of bronchial complications following lung transplantation and evaluate an effectiveness of endoscopic treatment of these events.

MATERIAL AND METHODS

The study enrolled 50 patients after bilateral lung transplantation (24 men and 26 women). Mean age of patients was 35.4±5 (19; 61) years. Ischemia of bronchial mucous membrane of the transplant was intraoperatively and postoperatively analyzed. We also assessed severity and prevalence of anastomotic and non-anastomotic cicatricial bronchial stenoses.

RESULTS

All patients after lung transplantation were diagnosed with bronchial complications, i.e. ischemia of bronchial mucous membrane of the transplant. In 76% of patients, these complications did not require endoscopic treatment. Surgical and endoscopic treatment was required in 24% of cases. Three patients (6%) underwent intraoperative correction of bronchial anastomosis. Bronchial suture failure was diagnosed in 3 patients (6%), cicatricial bronchial stenosis - in 6 (12%) cases. Endoscopic stenting was effective for recovery of bronchial patency with complete epithelialization of mucous membrane. Stenting of lobar bronchus with application of mitomycin C was effective in patients with non-anastomotic stenoses type III after lung transplantation.

CONCLUSION

Major bronchial complications occurred in 24% of patients after lung transplantation. Endoscopic treatment of bronchial complications using a self-fixing silicone endoprosthesis after lung transplantation was effective in all patients with anastomotic and non-anastomotic cicatricial strictures. Mitomycin C prevented excessive growth of granulation and scar tissue.

Multi-disciplinary management of patients with benign airway strictures: A review

Histologically benign airway strictures are frequently misdiagnosed as asthma or COPD and may present with severe symptoms including respiratory failure. A clear understanding of pathophysiology and existing classification systems is needed to determine the appropriate treatment options and predict clinical course. Clinically significant airway strictures can involve the upper and central airways extending from the subglottis to the lobar airways. Optimal evaluation includes a proper history and physical examination, neck and chest computed tomography, pulmonary function testing, endoscopy and serology. Available treatments include medical therapy, endoscopic procedures and open surgery which are based on the stricture's extent, location, etiology, morphology, severity of airway narrowing and patient's functional status. The acuity of the process, patient's co-morbidities and operability at the time of evaluation determine the need for open surgical or endoscopic interventions. The optimal management of patients with benign airway strictures requires the availability, expertise and collaboration of otolaryngologists, thoracic surgeons and interventional pulmonologists. Multidisciplinary airway teams can facilitate accurate diagnosis, guide management and avoid unnecessary procedures that could potentially worsen the extent of the disease or clinical course. Implementation of a complex airway program including multidisciplinary clinics and conferences ensures that such collaboration leads to timely, patient-centered and evidence-based interventions. In this article we outline algorithms of care and illustrate therapeutic techniques based on published evidence.

Long-term outcomes of metallic endobronchial stents in lung transplant recipients are not affected by bacterial colonization

OBJECTIVES

We evaluated associations of endobronchial stenting with airway bacterial colonization, the antimicrobial resistance profile, hospitalizations for pneumonia and survival in lung transplant recipients.

METHODS

This is a retrospective single-centre study of 582 recipients of lung transplant during 2002-2018. We compared outcomes of 57 patients (9.7%) who received endobronchial stents (intervention group) to a control group of 57 patients without stents who were matched one to one for age, sex, year of transplantation, unilateral/bilateral transplantation and underlying disease.

RESULTS

For the intervention compared to the control group, airway colonization was more common for Pseudomonas (86% vs 35%, P < 0.001), Acinetobacter (21% vs 7%, P = 0.05), Klebsiella (21% vs 5%, P = 0.02) and Staphylococcus species (11% vs 0%, P = 0.02). The respective proportions of patients with positive bronchoalveolar lavage cultures on the third post-transplantation day, the day of stent insertion and 6-month post-stent insertion were 47.4%, 50.9% and 65.4% for Pseudomonas sp.; 15.8%, 12.3% and 3.8% for Klebsiella sp.; and 8.8%, 5.3% and 5.8% for Acinetobacter sp. The mean number of hospitalizations for pneumonia per patient was higher, without statistical significance, in the intervention than the control group (1.5 ± 1.7 vs 0.9 ± 1.5, P = 0.1). Kaplan-Meier survival curves did not show a statistically significant difference between the intervention group and the entire group without endobronchial stents (n = 525) (P = 0.4).

CONCLUSIONS

Lung transplant recipients with endobronchial stents were more likely to be colonized with pathologic bacteria and having pneumonia; however, stent placement was not associated with increased long-term mortality with appropriate stent maintenance.

Utility and Safety of Airway Stenting in Distal Airways Stenosis After Lung Transplant

BACKGROUND

Airway complications after lung transplantation are a difficult to treat clinical entity. A subset of these patients develop progressive distal airway stenosis (DAS) and a total loss of lobar airways. Stents may be placed to prevent continued obstruction. However, there is little data to suggest stent placement provides durable airway patency or a reduction in the need for further interventions.

METHODS

A retrospective cohort study was conducted using patients with DAS who underwent a variety of interventions. Demographic information and complications were described using nonparametric methods. Lung function at 1 year and bronchoscopies per month were compared between stented and nonstented patients using a Mann-Whitney test. For patients treated with stenting, bronchoscopies per month were compared before and after stenting using a Wilcoxon signed-rank test. Airway patency was compared between stented and nonstented patients using the Fischer exact test.

RESULTS

Eleven airways were identified as DAS phenotype, 5 of which were treated with stents. Within the stented airways, a trend toward an increase in bronchoscopies per month was seen after stent placement. Comparing the stented versus nonstented patients, there was no improvement in lung function, no reduction in bronchoscopies per month, and no difference in airway patency for stented patients.

CONCLUSION

Patients with DAS phenotypes that were treated with endobronchial stenting did not require less airway intervention or have greater final airway patency compared with the nonstented airways. Among the stented patients, the need for airway manipulation did not decrease after stent placement.

Number of Bronchoscopic Interventions in Lung Transplant Recipients Correlates with Respiratory Function Assessed by Pulmonary Function Tests

Background

Lung transplant recipients may suffer from airway stenosis (AS). The aim of this study was to assess whether pulmonary function (as measured by spirometry and a 6-minute walk test [6MWT]) in patients with AS treated consistently with bronchoscopic interventions (BIs) was comparable to that in their AS-free counterparts at the 1-year follow-up visit.

Material/Methods

Fifty patients who underwent primary double-lung transplantation between January 2015 and March 2019 at a single center (23 who received BIs and 27 who did not) were enrolled in this retrospective study. Graft function was assessed with spirometry, based on forced expiratory volume (FEV₁) and forced vital capacity (FVC), both measured in liters (L) and percentages (%), and the Tiffeneau-Pinelli index (FEV₁/FVC), and a 6MWT and parameters such as oxygen saturation measured before and after the test.

Results

Patients in need of BIs had significantly lower FEV₁% compared with individuals who did not receive BIs during their first post-transplant year. Airway obstruction was present in 22% of patients who did not receive BIs and 65.23% of those who did receive the interventions. There were statistically significant, strong, negative correlations pertaining to the number of balloon BIs and 1-year FEV₁% (r_s=0.67) as well as the number of balloon BIs and 1-year FEV₁/FVC (r_s=0.72). A statistically significant, strong, negative correlation (r_s=0.75) was found between the number of balloon bronchoplasty treatments and oxygen saturation after the 6WMT.

Conclusions

Despite receiving BIs, patients who experience bronchial stenosis may not obtain the expected ventilatory improvement at their 1-year follow-up visit. Their AS may recur or persist despite use of various procedures. Further study in that regard is required.

Long-Term Success of Metal Endobronchial Stents in Lung Transplant Recipients

BACKGROUND

 Bronchial stenosis is a common complication following lung transplantation. We evaluated long-term associations of the use of self-expandable metal stents (SEMSs) with lung function tests, patient safety, and survival.

METHODS

 A retrospective chart review of 582 lung transplantations performed at our institution between January 2002 and January 2018. Fifty-four patients with SEMSs (intervention group) were matched one-to-one to patients without SEMSs (control group) using propensity score matching for age, sex, the year, and type of transplantation (unilateral/bilateral), and underlying disease. Data regarding long-term lung function and survival were compared between the groups.

RESULTS

 During a median follow-up of 54.8 months, the difference in survival between the study groups was not statistically significant (p = 0.2). Following 5, 7.5 and 10 years, values of mean forced expiratory volume in 1 second (FEV1) were comparable between patients with and without SEMSs as follows: 59.5 versus 62.6% (p = 0.2), 55.9 versus 55.0% (p = 0.4), and 63.5 versus 61.9% (p = 0.3), respectively. In the intervention group, a significant increase in the mean FEV1 was observed in 60 days after stent insertion (from 41.9 ± 12.8 to 49.5 ± 16.7% days, p < 0.001). Long-term complications following stent insertion included severe bleeding (1.8%), stent fractures (7.4%), stent stenosis (7.4%), stent collapse (3.7%), endobronchial pressure ulcer (1.9%), and stent migration (1.9%).

CONCLUSION

 SEMS insertion is associated with a positive sustained effect on lung function, without increasing long-term mortality. Thus, airway stenosis after lung transplantation can be safely and successfully treated using endobronchial metal stenting, with tight bronchoscopic follow-up and maintenance.

Efficacy and safety of airway stenting to treat anastomotic complications after lung transplant: a cohort study

Background

Airway complications affect roughly 15–20% of lung transplant patients. Airway stents are an attractive therapeutic option; however, no experimental or controlled observational data exists to draw firm conclusions regarding airway stent efficacy and safety in this population.

Methods

We performed a retrospective cohort study of patients who underwent airway stent placement for post-transplant anastomotic airway complications. The primary outcomes were improvements in FEV1 and reduction in bronchoscopies post-stent.

Results

We identified 36 patients who underwent airway stenting between October 2012 and October 2017. A total of 47 airways underwent stent placement. Improvement in FEV1 after stent placement was only observed in patients who ultimately were able to undergo stent removal. Patients who expired prior to stent removal had no immediate FEV1 improvement after stent placement. Among subjects who underwent stent removal, there was a statistically significant reduction in number of bronchoscopies per month after stent removal compared to pre-stent placement. Male gender was the only predictor of FEV1 improvement after stent placement while male gender and dehiscence prior to stent placement predicted increased number of bronchoscopies after stent placement. Mucous plugging and granulation tissue formation were the most common stent related complications.

Conclusions

Only select patients benefit from stent placement for airways stenosis after lung transplant. Complications related to stent placement are common. Patients with airway complications treated with airway stents undergo a high volume of repeat procedures.

Imaging Evaluation of Airway Complications After Lung Transplant

Airway complications (ACs) after lung transplant remain a challenge and include bronchial dehiscence, bronchial stenosis, tracheobronchomalacia, infections, and bronchial fistulas. The spectrum of complications may coexist along a continuum and can be classified as early (<1 month after transplant) or late (>1 month), and anastomotic or nonanastomotic. Bronchiolitis obliterans is the most common form of chronic lung allograft rejection. Airway compromise is seen in rare instances of lung torsion, and imaging may provide helpful diagnostic clues. Computed tomography (CT) and bronchoscopy play major roles in the diagnosis and treatment of ACs after lung transplant. Chest CT with advanced postprocessing techniques is a valuable tool in evaluating for airways complications, for initial bronchoscopic treatment planning and subsequent posttreatment assessment. Various bronchoscopic treatment options may be explored to maintain airway patency. The goal of this article is to review imaging findings of ACs after lung transplantation, with emphasis on chest CT and bronchoscopic correlation.

Single running suture technique is associated with low rate of bronchial complications after lung transplantation

BACKGROUND

Lung transplantation has evolved to a routinely performed surgical procedure in patients with end-stage pulmonary disease. Bronchial healing problems are rare but represent a potential life-threatening complication. Herein, we aimed to define the incidence, classification, and treatment of bronchial complications after lung transplantation.

MATERIAL AND METHODS

All patients receiving lung transplantation between January 1999 and December 2017 were included in this retrospective study. All bronchial anastomoses were performed in a standardized technique using a single, polydioxanone running suture. The rate of anastomotic complications requiring an intervention, type of complication according the 2018 International Society for Heart and Lung Transplantation classification, and the clinical management were retrospectively analyzed.

RESULTS

A total of 2941 anastomoses were performed in 1555 patients. The overall incidence of relevant anastomotic complications was 1.56%, 0.68% for left anastomoses, and 2.44% for right anastomoses. In 6 patients, a surgical revision or retransplantation was performed, whereas endoscopic treatment alone was sufficient in 39 patients. One patient underwent right-sided retransplantation 6 months after the first lung transplantation after failed endoscopic treatment attempts. International Society for Heart and Lung Transplantation grade "S Lc Ec" was the most common type of anastomotic complication. The overall incidence decreased within the study period from 2.4% in the era 1999 to 2003 to 0.8% in the era 2014 to 2017. We found no significant difference in overall survival of patients with and without anastomotic complications (P = .995; hazard ratio, 0.99; 95% confidence interval, 0.63-1.58).

CONCLUSIONS

The single running suture technique is associated with a very low rate of true anastomotic complications. Close follow-up and early endoscopic treatment of patients with anastomotic complications result in excellent long-term outcomes.

ISHLT Consensus Statement on adult and pediatric airway complications after lung transplantation: Definitions, grading system, and therapeutics

Airway complications remain a major cause of morbidity and mortality after cardiothoracic transplantation. The reported incidence of airway ischemic complications varies widely, contributed to by the lack of a universally accepted grading system and standardized definitions. Furthermore, the majority of the existing classification systems fail to integrate the wide range of possible bronchial complications that may develop after lung transplant. Hence, a Working Group was created by the International Society for Heart and Lung Transplantation with the aim of elaborating a universal definition of adult and pediatric airway complications and grading system. One such area of focus is to understand the problem in the context of a more standardized consensus of classifying airway ischemia. This consensus definition will have major clinical, therapeutics, and research implications.

Treatment of distal bronchial stenosis after bilateral lung transplantation

The effi ciency of lung transplantation is considerably limited by the complications associated with the bronchial pathologies. Despite the progress of the treatment methods, bronchial complications are still remaining as an actual problem in the postoperative period with frequency of occurrence from 7 to 29%. However, the bronchial stenosis are the most common bronchial complications after lung transplantation with mortality from 2 to 4%.

Aim. To study an experience of our center of bronchial stenosis treatment in lung recipients. Materials and methods. 34 patients underwent lung transplantation from September 2014 to January 2017. 6 (16%) of them had a stenosis of lobar or segmental bronchi from 84 to 494 postoperative day. 5 (83%) of them have demonstrated multifocal lesions. In all of the cases there was performed an endoscopic bougienage, which involved a balloon dilatation and electrocoagulated incision of granular tissue under X-ray control. After that the patients were administrated by everolimus.

Results. Restenosis was formed in 132,0 ± 94,2 postoperative day after primary treatment in all patients. In four cases (67%) we used nitinol stent placement under X-ray control. There were no complications. In 3 cases stents were dislocated distally, so we needed to use repeated endoscopic bougienage to replace the stent. Using of everolimus has allowed to decrease the rate of restenosis, but it need future research.

Conclusion. Distal bronchial stenosis after lung transplantation can be managed with endoscopic bougienage and stent placement. Adding everolimus has not signifi cantly affected the risk of frequency of restenosis.

Hypoxic Gene Expression of Donor Bronchi Linked to Airway Complications after Lung Transplantation

RATIONALE

Central airway stenosis (CAS) after lung transplantation has been attributed in part to chronic airway ischemia; however, little is known about the time course or significance of large airway hypoxia early after transplantation.

OBJECTIVES

To evaluate large airway oxygenation and hypoxic gene expression during the first month after lung transplantation and their relation to airway complications.

METHODS

Subjects who underwent lung transplantation underwent endobronchial tissue oximetry of native and donor bronchi at 0, 3, and 30 days after transplantation (n = 11) and/or endobronchial biopsies (n = 14) at 30 days for real-time polymerase chain reaction of hypoxia-inducible genes. Patients were monitored for 6 months for the development of transplant-related complications.

MEASUREMENTS AND MAIN RESULTS

Compared with native endobronchial tissues, donor tissue oxygen saturations (Sto2) were reduced in the upper lobes (74.1 ± 1.8% vs. 68.8 ± 1.7%; P < 0.05) and lower lobes (75.6 ± 1.6% vs. 71.5 ± 1.8%; P = 0.065) at 30 days post-transplantation. Donor upper lobe and subcarina Sto2 levels were also lower than the main carina (difference of -3.9 ± 1.5 and -4.8 ± 2.1, respectively; P < 0.05) at 30 days. Up-regulation of hypoxia-inducible genes VEGFA, FLT1, VEGFC, HMOX1, and TIE2 was significant in donor airways relative to native airways (all P < 0.05). VEGFA, KDR, and HMOX1 were associated with prolonged respiratory failure, prolonged hospitalization, extensive airway necrosis, and CAS (P < 0.05).

CONCLUSIONS

These findings implicate donor bronchial hypoxia as a driving factor for post-transplantation airway complications. Strategies to improve airway oxygenation, such as bronchial artery re-anastomosis and hyperbaric oxygen therapy merit clinical investigation.

Airway anastomosis for lung transplantation

Lung transplantation (LT) is the only viable option for a selected group of patients with end stage pulmonary diseases. During the recent years satisfactory results in terms of long-term survival and quality of life have been achieved with improvements in surgical technique, immunosuppression and perioperative management. Since the beginning, the airway anastomosis has been considered crucial and significant efforts have been made to understand the healing process. A number of experimental studies allowed improving the surgical technique by modifying the technique of suturing, the anastomotic protection and type and dose of immunosuppression, reducing the risk of airway complications. Furthermore, a huge progress has been made in the management of such complications. Early diagnosis of bronchial complications and their prompt and correct management are crucial to achieve long-term survival.

Airway complications after lung transplantation

Airway complications after lung transplantation present a formidable challenge to the lung transplant team, ranging from mere unusual images to fatal events. The exact incidence of complications is wide-ranging depending on the type of event, and there is still evolution of a universal characterization of the airway findings. Management is also wide-ranging. Simple observation or simple balloon bronchoplasty is sufficient in many cases, but vigilance following more severe necrosis is required for late development of both anastomotic and nonanastomotic airway strictures. Furthermore, the impact of coexisting infection, rejection, and medical disease associated with high-level immunosuppression further complicates care.

Paclitaxel-coated balloons in refractory nonanastomostic airway stenosis following lung transplantation

Airway stenosis represents the commonest airway complication following lung transplantation, affecting between 7% and 18% of patients. Existing treatment options offer limited efficacy and can cause additional patient morbidity. Paclitaxel-coated balloons (PCB) have proved effective in managing postinterventional coronary artery re-stenosis. In a first-in-man study, we evaluated similar PCBs in refractory nonanastomotic airway stenosis in 12 patients. Following a single application, luminal patency was maintained in 50% at 270 days. No significant peri-interventional or early postinterventional complications occurred. Given these encouraging initial findings, further studies appear warranted.

The surgical technique of bilateral sequential lung transplantation

Since the first successful lung transplant performed three decades ago, the technique of lung transplantation has evolved with acceptable short- and long-term outcomes such that it has become the standard for those with end stage pulmonary disease. Herein, we describe our current favored approach and discuss some of the current areas in need of further investigation as they relate to the technical aspects of the operation.

Safety and efficacy of outpatient bronchoscopy in lung transplant recipients - a single centre analysis of 3,197 procedures

BACKGROUND

Bronchoscopy represents an important diagnostic and therapeutic tool in the management of lung transplant (LTx) recipients. Outpatient bronchoscopy reduces health costs and may improve quality of life amongst these patients. This retrospective study assessed the safety and efficacy of outpatient bronchoscopy including trans-bronchial biopsy.

METHODS

All outpatient bronchoscopies performed on lung transplant recipients between 1 August 2008 and 31 January 2011 were reviewed. Sample quality, duration and complications were recorded. Cost analysis was performed from local trust financial data.

RESULTS

A total of 3,197 bronchoscopies were performed on 571 LTx recipients under topical anaesthesia. Fourteen percent of examinations required intravenous sedation. In 79.8% of examinations no complications were observed. Most complications were minor (17.9%) including cough (5.3%) and minimal bleeding after trans-bronchial biopsy (7.8%). Major complications (2.3%) were pneumothorax, severe bleeding and severe desaturation. No attributable deaths were recorded during the observation period. Quality of examination based on bronchoalveolar lavage recovery median (>50%) and biopsy results was adequate at 75% and 77.4%, respectively. Independent risk factors associated with complication were long-term oxygen therapy, sedation before examination, balloon dilatation and transbronchial biopsy. After excluding high-risk procedures annual savings per patient (2.2 bronchoscopies per year) were 2140€.

CONCLUSIONS

Outpatient bronchoscopy after LTx is safe. The low complication rate could be attributed to withholding of intravenous sedation. Furthermore, it reduces health community costs.

A comparative analysis of bronchial stricture after lung transplantation in recipients with and without early acute rejection

BACKGROUND

Risk factors and outcomes of bronchial stricture after lung transplantation are not well defined. An association between acute rejection and development of stricture has been suggested in small case series. We evaluated this relationship using a large national registry.

METHODS

All lung transplantations between April 1994 and December 2008 per the United Network for Organ Sharing (UNOS) database were analyzed. Generalized linear models were used to determine the association between early rejection and development of stricture after adjusting for potential confounders. The association of stricture with postoperative lung function and overall survival was also evaluated.

RESULTS

Nine thousand three hundred thirty-five patients were included for analysis. The incidence of stricture was 11.5% (1,077/9,335), with no significant change in incidence during the study period (P=0.13). Early rejection was associated with a significantly greater incidence of stricture (adjusted odds ratio [AOR], 1.40; 95% confidence interval [CI], 1.22-1.61; p<0.0001). Male sex, restrictive lung disease, and pretransplantation requirement for hospitalization were also associated with stricture. Those who experienced stricture had a lower postoperative peak percent predicted forced expiratory volume at 1 second (FEV1) (median 74% versus 86% for bilateral transplants only; p<0.0001), shorter unadjusted survival (median 6.09 versus 6.82 years; p<0.001) and increased risk of death after adjusting for potential confounders (adjusted hazard ratio 1.13; 95% CI, 1.03-1.23; p=0.007).

CONCLUSIONS

Early rejection is associated with an increased incidence of stricture. Recipients with stricture demonstrate worse postoperative lung function and survival. Prospective studies may be warranted to further assess causality and the potential for coordinated rejection and stricture surveillance strategies to improve postoperative outcomes.

Significance of and risk factors for the development of central airway stenosis after lung transplantation

Central airways stenosis (CAS) after lung transplant is a poorly understood complication. Objectives of this study were to determine if CAS was associated with chronic rejection or worse survival after transplant as well as to identify factors associated with CAS in a large cohort of lung transplant recipients. Lung transplant recipients transplanted at a single center were retrospectively reviewed for the development of CAS requiring airway dilation. A total of 467 subjects met inclusion criteria with 60 (13%) of these developing CAS requiring intervention. Of these 60 recipients, 22 (37%) had resolution of CAS with bronchoplasty alone, while 32 (53%) ultimately required stent placement. CAS that required intervention was not a risk factor for the development of bronchiolitis obliterans syndrome or worse overall survival. Significant risk factors for the subsequent development of CAS in a time-dependant multivariable model were pulmonary fungal infections and the need for postoperative tracheostomy. While CAS was not associated with BOS or worse survival, it remains an important complication after lung transplant with potentially preventable risk factors.

Short-term Placement of Multiple Self-expandable Metallic Stents for the Treatment of Bilateral Bronchial Dehiscences Complicating Lung Transplantation

Bronchial dehiscence after lung transplantation is a rare complication yet has high morbidity and mortality. The majority of the patients are not surgical candidates. We present the case of a 59-year-old man with bilateral lung transplantation for interstitial pulmonary fibrosis who was readmitted with symptoms of acute rejection and severe hypoxemic respiratory failure on day 14. Bronchoscopy showed bilateral bronchial anastomotic dehiscences. A computerized tomography scan showed evidence of significant peribronchial air collection in the pleural space and the mediastinum. Owing to a high predictive operative mortality, endobronchial management was planned, and 3 uncovered self-expanding metallic stents (Ultraflex, Boston Scientific Corp) were placed (in the left main stem bronchus, the anterior segment of the right upper lobe, and the right intermediate bronchus). At 5 weeks bronchoscopy showed complete healing of the dehiscences with granulation. The stents were then removed by rigid bronchoscopy. Three weeks after the stent removal a bronchoscopic examination showed a normal tracheobronchial tree except for a slightly narrowed right anastomosis. We conclude that short-term placement of uncovered self-expanding metallic stents provides a safe and minimally invasive option in the management of bilateral dehiscences.

The management of bronchus intermedius complications after lung transplantation: a retrospective study

Background

Airway complications following lung transplantation remain a significant cause of morbidity and mortality. The management of bronchial complications in Bronchus Intermedius (BI) is challenging due to the location of right upper bronchus. The aim of this study was to analyze the results of BI Montgomery T-tube stent in a consecutive patients with lung transplantations.

Methods

Between January 2007 and December 2010, 132 lung transplantations were performed at Foch Hospital, Suresnes, France. All the patients who had BI Montgomery T-tube after lung transplantation were included in this retrospective study. The demographic and interventional data and also complications were recorded.

Results

Out of 132 lung transplant recipients, 12 patients (9 male and 3 female) were entered into this study. The indications for lung transplantation were: cystic fibrosis 8 (67%), emphysema 3 (25%), and idiopathic pulmonary fibrosis 1 (8%). Most of the patients (83%) had bilateral lung transplantation. The mean interval between lung transplantation and interventional bronchoscopy was 11.5 ± 9.8 (SD) months. There was bronchial stenosis at the level of BI in 7 patients (58.3%). The Montgomery T-tube number 10 was used in 9 patients (75%). There was statistically significant difference in Forced Expiratory Volume in one second (FEV1) before and after stent placement (p = 0.01). The most common complication after stent placement was migration (33%).

Conclusion

BI complications after lung transplantation are still a significant problem. Stenosis or malacia following lung transplantation could be well managed with modified Montgomery T-tube.

Respiratory infections increase the risk of granulation tissue formation following airway stenting in patients with malignant airway obstruction

BACKGROUND

The most serious complications of airway stenting are long term, including infection and granulation tissue formation. However, to our knowledge, no studies have quantified the incidence rate of long-term complications for different stents.

METHODS

To compare the incidence of complications of different airway stents, we conducted a retrospective cohort study of all patients at our institution who had airway stenting for malignant airway obstruction from January 2005 to August 2010. Patients were excluded if more than one type of stent was in place at the same time. Complications recorded were lower respiratory tract infections, stent migration, granulation tissue, mucus plugging requiring intervention, tumor overgrowth, and stent fracture.

RESULTS

One hundred seventy-two patients with 195 stent procedures were included. Aero stents were associated with an increased risk of infection (hazard ratio [HR] = 1.98; 95% CI, 1.03-3.81; P = .041). Dumon silicone tube stents had an increased risk of migration (HR = 3.52; 95% CI, 1.41-8.82; P = .007). Silicone stents (HR = 3.32; 95% CI, 1.59-6.93; P = .001) and lower respiratory tract infections (HR = 5.69; 95% CI, 2.60-12.42; P < .001) increased the risk of granulation tissue. Lower respiratory tract infections were associated with decreased survival (HR = 1.57; 95% CI, 1.11-2.21; P = .011).

CONCLUSIONS

Significant differences exist among airway stents in terms of infection, migration, and granulation tissue formation. These complications, in turn, are associated with significant morbidity and mortality. Granulation tissue formation develops because of repetitive motion trauma and infection.

Successfully treated postbronchoplasty bronchial stenosis using short-interval repeated endobronchial balloon dilation

A 63-year-old man with a history of lung cancer underwent lobectomy of the right upper lobe and bronchoplasty. At the 2-month follow-up, bronchial stenosis due to a granuloma was observed. Endoscopic débridement and balloon dilation were performed. At 1 month after the dilation, atelectasis occurred owing to cicatricial stenosis. We repeated balloon dilation, but the patient suffered from cicatricial restenosis. After a failed stent placement, balloon dilation was then performed every 2 weeks under local anesthesia; the stenosis was resolved after performing dilation 7 times. Short-term repeated balloon dilation was effective in this case.

Interventional techniques in the management of airway complications following lung transplantation

The last four decades have seen tremendous advances in the field of pulmonary transplantation. Vast improvements in the areas of surgical transplantation techniques, immunosuppressive agents, and postoperative care have all contributed to improved survival of patients. Advances in noninvasive imaging and bronchoscopy have allowed the pulmonary transplant team to intervene early in patients presenting with airway complications, often using minimally invasive procedures such as endobronchial balloon dilation or stent placement, or both. Stent technology itself has also improved and stents may sometimes be customized for treatment of short airway lesions or to optimize continued airflow through the sides of stents by creating openings using balloons or bronchoscopically directed laser. Preliminary work with brachytherapy may be decreasing the need for secondary reinterventions. The authors present an overview of some of these conventional and novel approaches to the treatment of airway complications after lung transplantation.

Determination of predictive factors of tracheobronchial prosthesis removal: stent brands are crucial

OBJECTIVES

We sought to describe in a retrospective study our experience in the endoscopic management of tracheobronchial stenoses over 20 years and to determine prognostic factors of stent removal.

METHODS

We analyzed the medical records of 166 patients (111 male and 55 female) who underwent the placement of a prosthesis for all causes of tracheobronchial stenosis between 1990 and 2009.

RESULTS

Overall, 34% of the patients had their stents removed. The incidence of complications for the first stent was 0.08 per patient-month. One hundred five patients (63%) had no complications. In univariate analysis, stent removal was significantly linked with the stent brand. In multivariate analysis, taking into account the causes of stenosis, the stent brand appeared to be the only factor that significantly influenced stent removal. Finally, stenosis with more than 1 stent replacement was most prone to repeat endoscopies.

CONCLUSIONS

Even though endoscopic stent placement is a relatively safe and effective treatment for tracheobronchial stenoses, particularly in cases with malignancy, complications led to stent removal in about one third of cases. The type of stent chosen is crucial.