Bronchial Complications Following Lung Transplantation

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.

Risk factors and prognosis of airway complications in lung transplant recipients: A systematic review and meta-analysis

BACKGROUND

Airway complications (AC) are one of leading causes of morbidity and mortality after lung transplant (LTx), but their predictors and outcomes remain controversial. This study aimed to identify potential risk factors and prognosis of AC.

METHODS

A systematic review was performed by searching PubMed, Embase, and Cochrane Library. All observational studies reporting outcome and potential factors of AC after LTx were included. The incidence, mortality, and estimated effect of each factor for AC were pooled by using the fixed-effects model or random-effects model.

RESULTS

Thirty-eight eligible studies with 52,116 patients undergoing LTx were included for meta-analysis. The pooled incidence of AC was 12.4% (95% confidence interval [CI] 9.5-15.8) and the mean time of occurrence was 95.6 days. AC-related mortality rates at 30-days, 90-days, 6 months, 1 year, and 5 years were 6.7%, 17.9%, 18.2%, 23.6%, and 66.0%, respectively. Airway dehiscence was the most severe type with a high mortality at 30 days (60.9%, 95% CI 20.6-95.2). We found that AC was associated with a higher risk of mortality in LTx recipients (hazard ratio [HR] 1.71, 95% CI 1.04-2.81). Eleven significant predictors for AC were also identified, including male donor, male recipient, diagnosis of COPD, hospitalization, early rejection, postoperative infection, extracorporeal membrane oxygenation, mechanical ventilation, telescopic anastomosis, and bilateral and right-sided LTx.

CONCLUSION

AC was significantly associated with higher mortality after LTx, especially for dehiscence. Targeted prophylaxis for modifiable factors and enhanced early bronchoscopy surveillance after LTx may improve the disease burden of AC.

POST-OPERATIVE BRONCHIAL COMPLICATIONS FOLLOWING LUNG TRANSPLANTATION RELATED TO ANASTOMOSIS SUTURE

BACKGROUND

Post-operative bronchial anastomotic complications are not uncommon in lung transplant (LTx) recipients. We investigated two surgical techniques (continuous and interrupted sutures) during bronchial anastomosis, comparing survival and post-operative bronchial complications.

METHODS

We retrospectively analyzed 421 patients who were transplanted in our center (February-2012 to March-2018). Patients were divided according to bronchial anastomotic technique, continuous or interrupted. Demographics and clinical parameters were compared for significance (p<0.05). Comparison of post-operative morbidity included bronchial complications, Veno-Venous extracorporeal membrane oxygenation support and intervention requirements. Survival was assessed using Kaplan-Meier curve and log-rank tests (p<0.05).

RESULTS

Of the 421 patients, 290 underwent bronchial anastomoses with continuous suture; 44 patients had post-operative bronchial complications (15.2%). Contrarily, 131 patients underwent the interrupted suture technique; 9 patients had post-operative bronchial complications (6.9%). Demographics and clinical parameters included age, gender, ethnicity, etiology, lung allocation score, body mass index, donor age, LTx type, cardiopulmonary bypass usage, surgical approaches, and median length of stay. Post-operative complications (continuous vs. interrupted) were bronchial complications (p=0.017), Veno-venous extracorporeal membrane oxygenation support (p=0.41), Veno-arterial extracorporeal membrane oxygenation support (p=0.38), and complications requiring dilatation with stent placement (p=0.09). Kaplan-Meier curve showed better survival in the interrupted group (p=0.0002).

CONCLUSIONS

Our study demonstrated the comparable post-operative results between the continuous and interrupted technique.

[Airway complications after lung transplantation]

Lung transplantations have been regularly performed in the Russian Federation since 2010. Therefore, the number of lung transplant recipients, as well as the number of patients with airway complications following lung transplantation has been increasing. Treatment of these patients takes place not only in transplantation centers, but also in other hospitals. This review is devoted to risk factors, clinical manifestations, treatment and prevention of airway complications after lung transplantation. We analyzed literature data over the last 15 years. It was confirmed that bronchoscopy is a «gold standard» for diagnosis of airway complications while bronchoscopic interventions are preferred for treatment. Balloon and rigid bronchodilation and endoscopic airway stenting are the most effective interventions. Silicone stents are the most optimal. Antimicrobial prophylaxis and timely use of antiproliferative immunosuppressive drugs are important factors in prevention and treatment of airway complications after lung transplantation.

A proof-of principal study using phase-contrast imaging for the detection of large airway pathologies after lung transplantation

In this study we aim to evaluate the assessment of bronchial pathologies in a murine model of lung transplantation with grating-based X-ray interferometry in vivo. Imaging was performed using a dedicated grating-based small-animal X-ray dark-field and phase-contrast scanner. While the contrast modality of the dark-field signal already showed several promising applications for diagnosing various types of pulmonary diseases, the phase-shifting contrast mechanism of the phase contrast has not yet been evaluated in vivo. For this purpose, qualitative analysis of phase-contrast images was performed and revealed pathologies due to previous lung transplantation, such as unilateral bronchial stenosis or bronchial truncation. Dependent lung parenchyma showed a strong loss in dark-field and absorption signal intensity, possibly caused by several post transplantational pathologies such as atelectasis, pleural effusion, or pulmonary infiltrates. With this study, we are able to show that bronchial pathologies can be visualized in vivo using conventional X-ray imaging when phase-contrast information is analysed. Absorption and dark-field images can be used to quantify the severity of lack of ventilation in the affected lung.

Vanishing Middle Bronchus in Bilateral Lung Transplant After Ex Vivo Lung Perfusion

Lung transplant has become the mainstay of therapy for most end-stage lung diseases. Airway complications are one of the most important problems during the first year after lung transplant. In this context, the most severe form of bronchial stenosis reported in the literature is vanishing bronchus syndrome, which is the obliteration with atresia of the ostium of a lobar bronchus, usually related to ischemia and infection. Ex vivo lung perfusion is a novel strategy forlung allograft preservation that keeps the organs at physiologic protective conditions. Nevertheless, many ex vivo systems work with lungs in supine position, and upperregions (middle lobe and lingula) can have lower perfusion supply, increasing the risk of a relative ischemia. We report a case of vanishing middle bronchus after ex vivo reconditioning bilateral lung transplant in a 45-year-old man with nonspecific interstitial pneumonia, whose posttransplant course was complicated by Aspergillusfumigatus infection.

Surgical Strategy for Lung Transplantation in Adults With Small Chests: Lobar Transplant Versus a Pediatric Donor

BACKGROUND

Adult lung transplant recipients with small chests have traditionally received lungs from pediatric donors, placing an additional strain on the already restricted pediatric donor pool. Performing lobar lung transplantation (LLT) can circumvent issues with donor-recipient size mismatch; however, LLT imparts additional risks. Here, we review our experience using LLT and standard lung transplantation using a pediatric donor (PDLT) for adults with small chests.

METHODS

We retrospectively reviewed consecutive patients with end-stage lung disease and a height of 65 inches or less who underwent LLT (n = 15) or PDLT (n = 15) between 2006 and 2012 at our institution, a high-volume lung transplant center.

RESULTS

Lobar lung transplantation recipients were older (54 ± 10 vs 48 ± 8 years) and had higher pulmonary pressure (57 ± 11 vs 52 ± 27 mmHg) and higher lung allocation scores (70 ± 9 vs 51 ± 8) than PDLT recipients (all P < 0.05). Mean waiting time was 62 days for PDLT and 9 days for LLT. Postoperatively, the incidence of severe primary graft dysfunction and the incidence of acute renal insufficiency were higher, and the mean intensive care unit stay was longer in the LLT group, but the incidence of bronchial anastomotic complications was higher in the PDLT group because of significant size discrepancy in the main bronchus (P < 0.05). Interestingly, long-term functional outcomes and survival rates were similar between the groups.

CONCLUSIONS

Both LLT and PDLT are viable surgical options for adult patients with small chests. Because of the potential impact on posttransplant outcomes, the technical complexity of transplantation, decisions regarding the best surgical approach should be made by experienced surgeons.

Lung transplantation: overall approach regarding its major aspects

Lung transplantation is a well-established treatment for patients with advanced lung disease. The evaluation of a candidate for transplantation is a complex task and involves a multidisciplinary team that follows the patient beyond the postoperative period. Currently, the mean time on the waiting list for lung transplantation in the state of São Paulo, Brazil, is approximately 18 months. For Brazil as a whole, data from the Brazilian Organ Transplant Association show that, in 2014, there were 67 lung transplants and 204 patients on the waiting list for lung transplantation. Lung transplantation is most often indicated in cases of COPD, cystic fibrosis, interstitial lung disease, non-cystic fibrosis bronchiectasis, and pulmonary hypertension. This comprehensive review aimed to address the major aspects of lung transplantation: indications, contraindications, evaluation of transplant candidates, evaluation of donor candidates, management of transplant recipients, and major complications. To that end, we based our research on the International Society for Heart and Lung Transplantation guidelines and on the protocols used by our Lung Transplant Group in the city of São Paulo, Brazil.

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.

Lung transplantation: a treatment option in end-stage lung disease

BACKGROUND

Lung transplantation is the final treatment option in the end stage of certain lung diseases, once all possible conservative treatments have been exhausted. Depending on the indication for which lung transplantation is performed, it can improve the patient's quality of life (e.g., in emphysema) and/ or prolong life expectancy (e.g., in cystic fibrosis, pulmonary fibrosis, and pulmonary arterial hypertension). The main selection criteria for transplant candidates, aside from the underlying pulmonary or cardiopulmonary disease, are age, degree of mobility, nutritional and muscular condition, and concurrent extrapulmonary disease. The pool of willing organ donors is shrinking, and every sixth candidate for lung transplantation now dies while on the waiting list.

METHOD

We reviewed pertinent articles (up to October 2013) retrieved by a selective search in Medline and other German and international databases, including those of the International Society for Heart and Lung Transplantation (ISHLT), Eurotransplant, the German Institute for Applied Quality Promotion and Research in Health-Care (Institut für angewandte Qualitätsförderung und Forschung im Gesundheitswesen, AQUA-Institut), and the German Foundation for Organ Transplantation (Deutsche Stiftung Organtransplantation, DSO).

RESULTS

The short- and long-term results have markedly improved in recent years: the 1-year survival rate has risen from 70.9% to 82.9%, and the 5-year survival rate from 46.9% to 59.6%. The 90-day mortality is 10.0%. The postoperative complications include acute (3.4%) and chronic (29.0%) transplant rejection, infections (38.0%), transplant failure (24.7%), airway complications (15.0%), malignant tumors (15.0%), cardiovascular events (10.9%), and other secondary extrapulmonary diseases (29.8%). Bilateral lung transplantation is superior to unilateral transplantation (5-year survival rate 57.3% versus 47.4%).

CONCLUSION

Seamless integration of the various components of treatment will be essential for further improvements in outcome. In particular, the follow-up care of transplant recipients should always be provided in close cooperation with the transplant center.

Lung transplantation in patients with cystic fibrosis

Cystic fibrosis (CF) an autosomal recessive genetic disorder, affects many organs. The great majority of deaths occur due to respiratory failure after many years of chronic pulmonary infection. Despite recent progress in early detection by studies of genetic mutations and better understanding to treat nutritional and infectious states, lung transplantation is the CF treatment for most advanced cases. According to the International Society for Heart and Lung Transplantation (ISHLT) data, CF is the third most common reason for lung transplantation (16.8%) showing the best survival rate (60% at 5 years). We have described our experience in lung transplantation of CF patients between January 2000 and December 2011, reviewing medical charts of these patients were for gender, age, body mass index (BMI), comorbidities, disease duration, previous sputum gram stain, ischemic time, incidence of severe primary graft dysfunction (PGD Grade 3), intensive care unit (ICU) length of stay, and Kaplan-Meier survival. Among 150 lung transplantation, the 30 CF patients (20%) represented the second most common cause. The average age was 27.4 ± 9.2 years, with a slight predominance of males (n = 16; 53.3%). The average BMI was 18.9 ± 2.6. Most patients (60%) had pancreatic exocrine dysfunction. Also, 83.3% of patients showed a positive sputum culture for Pseudomonas, while Burkholderia cepacia was identified in only 4 patients (13.3%). The average time of the disease was 20.8 ± 9.7 years. All transplantation were bilateral with an average ischemic time of 472 ± 98.3 minutes and ICU length of stay of 9.9 ± 6.3 days. The survival rates at 1 and 5 years were 92% and 77%, respectively, corresponding to the best outcomes among underlying diseases, comparable with other worldwide series and better than the ISHLT reports. CF, the second most common cause for lung transplantation among our cases, showed the best survival rate among all causes. Our survival rate was comparable with other reports.

Repair of a bronchovascular fistula four years after right carinal pneumonectomy

Bronchovascular fistula is a rare but serious complication that usually presents with massive hemoptysis and is associated with a high risk of mortality. Factors leading to the development of the fistula include altered bronchial anastomotic healing, presence of granulation tissue, devascularization of the bronchial tree, ischemia of the airway, and poor anastomotic technique. Bronchovascular fistulae usually occur in the early postoperative period and are reported in 1% to 3% of the patients undergoing a bronchoplastic procedure. We report the case of a 53-year-old woman who presented with massive hemoptysis secondary to a bronchovascular fistula 4 years after right carinal pneumonectomy.

Vanishing bronchus intermedius syndrome in a pediatric patient with cystic fibrosis after lung transplantation

Airway complications occur frequently after lung transplantation. Bronchial stenosis is the most frequently encountered complication with the most severe form of that being the vanishing bronchus intermedius syndrome (VBIS). This rare disorder has never been reported in the pediatric population. This is the first report of VBIS in a pediatric patient, specifically a 16-yr-old male patient with cystic fibrosis whose course was complicated by a lower airway infection with Aspergillus fumigatus. The VBIS responded to bronchoscopic balloon dilation and placement of an airway stent.

The effects on mucociliary clearance of prednisone associated with bronchial section

OBJECTIVE

Infections have been and remain the major cause of morbidity and mortality after lung transplantation. Because mucociliary clearance plays an important role in human defense mechanisms, the influence of drugs on the mucociliary epithelium of patients undergoing lung transplantation must be examined. Prednisone is the most important corticosteroid used after lung transplantation. The aim of this study was to evaluate the effects of bronchial transection and prednisone therapy on mucociliary clearance.

METHODS

A total of 120 rats were assigned to 4 groups according to surgical procedure or drug therapy: prednisone therapy (1.25 mg/kg/day); bronchial section and anastomosis + prednisone therapy (1.25 mg/kg/day); bronchial section + saline solution (2 ml/day); and saline solution (2 ml/day). After 7, 15, or 30 days, the animals were sacrificed, and the lungs were removed from the thoracic cavity. The in situ mucociliary transport velocity, ciliary beat frequency and in vitro mucus transportability were evaluated.

RESULTS

Animals undergoing bronchial section surgery and anastomosis had a significant decrease in the ciliary beat frequency and mucociliary transport velocity 7 and 15 days after surgery (p<0.001). These parameters were normalized 30 days after the surgical procedure. Prednisone improved mucous transportability in the animals undergoing bronchial section and anastomosis at 15 and 30 days (p<0.05).

CONCLUSION

Bronchial section and anastomosis decrease mucociliary clearance in the early postoperative period. Prednisone therapy improves mucus transportability in animals undergoing bronchial section and anastomosis.

Outcome of Treating Airway Compromise due to Bronchial Stenosis with Intralesional Corticosteroids and Cutting-Balloon Bronchoplasty

Objectives. To determine the feasibility, safety, and efficacy of treating benign bronchial stenosis with laryngoscopy, jet ventilation, intralesional corticosteroids, and cutting-balloon bronchoplasty.

Study Design. Case series with planned data collection.

Setting. National airway unit.

Subjects and Methods. Ten adult patients with bronchial stenosis caused by Wegener’s granulomatosis (n = 6), tuberculosis (n = 2), intubation (n = 1), and photodynamic therapy (n = 1) who underwent bronchoplasty using cutting-balloon dilation via suspension laryngoscopy in 2009. Information about patient demography, etiology, lesion characteristics, and details of the interventions were recorded. Patients underwent spirometry before surgery and at last follow-up. Chest infection rate in the 6 months before bronchoplasty and from bronchoplasty to the last follow-up was ascertained.

Results. There were 3 men and 7 women. Mean age at bronchoplasty was 46 ± 20 years. Length of stay was 1 day in all cases, and no treatment-related complications occurred. One patient required a second bronchoplasty at 55 days. Mean follow-up was 7 ± 2.3 months. Forced expiratory volume in 1 second increased from a prebronchoplasty mean of 1.6 ± 0.6 to 2.2 ± 0.5 at last follow-up ( P < .0001; paired Student t test). Forced vital capacity rose from 2.7 ± 0.6 to 3.1 ± 0.6 ( P = .02), and peak expiratory flow rate increased from 3.7 ± 0.8 to 5.0 ± 0.8 ( P < .0001). Chest infection rate fell from an average of 0.7 ± 0.3 infections per month to 0.2 ± 0.2 ( P < .003; paired Student t test).

Conclusion. Cutting-balloon bronchoplasty via suspension laryngoscopy is an effective treatment for benign bronchial stenosis. It is safer than airway stenting and is less invasive than thoracotomy. The authors propose its use as first-line treatment for this condition.

Reduction in airway complications after lung transplantation with novel anastomotic technique

BACKGROUND

Bronchial anastomotic complications develop in 31% of lung transplant recipients, leading to additional operative procedures and increased morbidity. Advances in surgical technique have thus far resulted in only modestly improved outcomes. We hypothesized that creating the bronchial anastomosis at the secondary carina using a combination of running and figure-of-eight sutures would minimize donor bronchial ischemia and airway complications.

METHODS

This retrospective review of a single surgeon's operative experience from 2000 to 2007 compares a new bronchial anastomotic technique with the conventional technique. The primary outcome was the occurrence of bronchial anastomotic complications requiring invasive intervention. The secondary outcome was distal airway complications. Patients were monitored for 1 year after transplant. Recipient and donor demographic data as well as relevant variables from their preoperative, perioperative, and postoperative courses were collected for analysis. These data were compared using t tests for normally distributed continuous variables, Mann-Whitney tests for nonnormally distributed continuous variables, and χ2 tests or Fisher exact test for categoric variables. Logistic regression was used to control for covariates while comparing the primary outcome between the new and conventional bronchial anastomotic techniques.

RESULTS

The analysis included 230 patients, representing 407 anastomoses. The occurrence of anastomotic complications requiring intervention and distal airway complications decreased from 18.1% to 2.3% of anastomoses and 12.2% to 4.4% of patients, respectively. After controlling for available risk factors, the new technique significantly reduced both anastomotic (p<0.001) and distal (p=0.03) airway complications.

CONCLUSIONS

This new anastomotic technique dramatically reduces anastomotic and distal airway complications after lung transplantation.

[Lung hyperinflation after single lung transplantation to treat emphysema]

Despite preventive measures, lung hyperinflation is a relatively common complication following single lung transplantation to treat pulmonary emphysema. The progressive compression of the graft can cause mediastinal shift and respiratory failure. In addition to therapeutic strategies such as independent ventilation, the treatment consists of the reduction of native lung volume by means of lobectomy or lung volume reduction surgery. We report two cases of native lung hyperinflation after single lung transplantation. Both cases were treated by means of lobectomy or lung volume reduction surgery.

Removal of metallic tracheobronchial stents in lung transplantation with flexible bronchoscopy

Background

Airway complications are among the most challenging problems after lung transplantation, and Self-Expandable Metallic Stents (SEMS) are used to treat airway complications such as stenosis or malacia at the bronchial anastomosis sites. Several transplantation centers are reluctant to use SEMS since their removal is sometimes needed and usually requires the use of rigid bronchoscopy under general anesthesia. The objective of the current report is to describe our experience in SEMS retrieval by flexible bronchoscopy under conscious sedation.

Methods

A retrospective review was done of patients requiring tracheobronchial stent placement after lung transplantation in which the SEMS had to be removed. The retrieval procedure was done by flexible bronchoscopy on a day-care ambulatory basis.

Results

Between January 2004 and January 2010, out of 305 lung transplantation patients, 24 (7.8%) underwent SEMS placement. Indications included bronchial stenosis in 20 and bronchomalacia in 4. In six patients (25%) the SEMS had to be removed due to excessive granulation tissue formation and stent obstruction. The average time from SEMS placement to retrieval was 30 months (range 16-48 months). The stent was completely removed in five patients and partially removed in one patient; no major complications were encountered, and all patients were discharged within 3 hours of the procedure. In all procedures, new SEMS was successfully re-inserted thereafter.

Conclusions

The retrieval of SEMS in patients that underwent lung transplantation can be effectively and safely done under conscious sedation using flexible bronchoscopy on a day-care basis, this observation should encourage increasing usage of SEMS in highly selected patients.