Bilateral Lung Transplantation Provides Better Long-term Survival and Pulmonary Function Than Single Lung Transplantation: A Systematic Review and Meta-analysis

Survival Tree Provides Individualized Estimates of Survival After Lung Transplant

INTRODUCTION

Identifying contributors to lung transplant survival is vital in mitigating mortality. To enhance individualized mortality estimation and determine variable interaction, we employed a survival tree algorithm utilizing recipient and donor data.

METHODS

United Network Organ Sharing data (2000-2021) were queried for single and double lung transplants in adult patients. Graft survival time <7 d was excluded. Sixty preoperative and immediate postoperative factors were evaluated with stepwise logistic regression on mortality; final model variables were included in survival tree modeling. Data were split into training and testing sets and additionally validated with 10-fold cross validation. Survival tree pruning and model selection was based on Akaike information criteria and log-likelihood values. Estimated survival probabilities and log-rank pairwise comparisons between subgroups were calculated.

RESULTS

A total of 27,296 lung transplant patients (8175 single; 19,121 double lung) were included. Stepwise logistic regression yielded 47 significant variables associated with mortality. Survival tree modeling returned six significant factors: recipient age, length of stay from transplant to discharge, recipient ventilator duration post-transplant, double lung transplant, recipient reintubation post-transplant, and donor cytomegalovirus status. Eight subgroups consisting of combinations of these factors were identified with distinct Kaplan-Meier survival curves.

CONCLUSIONS

Survival trees provide the ability to understand the effects and interactions of covariates on survival after lung transplantation. Individualized survival probability with this technique found that preoperative and postoperative factors influence survival after lung transplantation. Thus, preoperative patient counseling should acknowledge a degree of uncertainty given the influence of postoperative factors.

From plugging air leaks to reducing lung volume: a review of the many uses of endobronchial valves

INTRODUCTION

One-way endobronchial valve treatment improves lung function, exercise capacity, and quality of live in patients with severe emphysema and hyperinflation. Other areas of therapeutic application include treatment of persistent air leak (PAL), giant emphysematous bullae, native lung hyperinflation, hemoptysis, and tuberculosis.

AREAS COVERED

In this review, we will assess the clinical evidence and safety of the different applications of one-way endobronchial valves (EBV).

EXPERT OPINION

There is solid clinical evidence for the use of one-way EBV for lung volume reduction in emphysema. Treatment with one-way EBV can be considered for the treatment of PAL. The application of one-way EBV for giant bullae, post lung transplant native lung hyperinflation, hemoptysis, and tuberculosis is under investigation and more research is required to investigate the efficacy and safety of these applications.

Time Trends in Clinical Characteristics and Hospital Outcomes of Hospitalizations for Lung Transplantation in COPD Patients in Spain from 2016 to 2020-Impact of the COVID-19 Pandemic

(1) Background: To examine the clinical characteristics and hospital outcomes of hospitalization for lung transplantation in COPD patients in Spain from 2016 to 2020; and to assess if the COVID-19 pandemic has affected the number or the outcomes of lung transplantations in these patients. (2) Methods: We used the Spanish National Hospital Discharge Database to select subjects who had a code for COPD (ICD-10: J44) and had undergone a lung transplantation (ICD-10 codes OBYxxxx). (3) Results: During the study period, 704 lung transplants were performed among COPD patients (single 31.68%, bilateral 68.32%). The absolute number of transplants increased with raising rates of 8%, 14% and 19% annually from 2016 to 2019. However, a marked decrease of -18% was observed from 2019 to year 2020. Overall, 47.44% of the patients suffered at least one complication, being the most frequent lung transplant rejection (24.15%), followed by lung transplant infection (13.35%). The median length of hospital stay (LOHS) was 33 days and the in-hospital-mortality (IHM) was 9.94%. Variables associated with increased risk of mortality were a Comorbidity Charlson Index ≥ 1 (OR 1.82; 95%CI 1.08-3.05) and suffering any complication of the lung transplantation (OR 2.14; 95%CI 1.27-3.6). COPD patients in 2020 had a CCI ≥ 1 in a lower proportion than 2019 patients (29.37 vs. 38.51%; p = 0.015) and less frequently suffered any complications after the lung transplantation (41.26 vs. 54.6%; p = 0.013), no changes in the LOHS or the IHM were detected from 2019 to 2020. (4) Conclusions: Our study showed a constant increase in the number of lung transplantations from 2016 to 2019 in COPD patients, with a drop from 2019 to 2020, probably related to the COVID-19 pandemic. However, no changes in LOHS or IHM were detected over time.

Health-Related Quality of Life Outcomes Following Single or Bilateral Lung Transplantation: A Systematic Review

BACKGROUND

Lung transplantation is the definitive treatment for end-stage lung disease. There has been uncertainty regarding whether single or bilateral lung transplantation confers patients' greater health-related quality of life. This systematic review was performed to evaluate the impact of single lung transplantation (SLTx) against bilateral lung transplantation on short- and long-term health-related quality of life.

METHODS

A literature search was conducted on PubMed for studies matching the eligibility criteria between January 2000 and January 2022. OVID (MEDLINE), Google Scholar, EBSCOhost (EMBASE), and bibliographies of included studies were reviewed. Inclusion of studies was based on predetermined eligibility criteria. Quality appraisal and data tabulation were performed using predetermined forms. Results were synthesized by narrative review. The structure of this systematic review follows the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. This systematic review was prospectively registered in the PROSPERO register (CRD42022344389).

RESULTS

Ten studies (1916 patients) were included. Within 12 mo posttransplantation, there was no evidence of the improved health-related quality of life with respect to the type of lung transplantation procedure. Bilateral lung transplantation patients reported significantly greater scores in both the physical and mental health domains of health-related quality of life. Bilateral lung transplantation offered significantly better health-related quality of life outcomes at later follow-up periods. Bilateral lung transplantation showed a significantly slower reduction in health-related quality of life physical composite scores relative to SLTx.

CONCLUSION

Bilateral lung transplant (BLTx) recipients perceive the greater health-related quality of life beyond 1-y post-lung transplantation. BLTx recipients better retain their health-related quality of life long-term posttransplantation than those receiving SLTx.

An Intention-to-treat View of Lung Transplantation for Interstitial Lung Disease: Successful Strategies to Minimize Waiting List and Posttransplant Mortality

BACKGROUND

Access to lung transplantation (LTx) and rates of waiting list and posttransplant mortality for patients with interstitial lung disease (ILD) remain problematic. We evaluated the outcomes of ILD patients listed for LTx at our institution.

METHODS

Between 2012 and 2018, adult patients with ILD were listed and transplanted from a donor-pool that included extended criteria and donation after circulatory-determined death donors. Patients were categorized as experiencing 1 of 4 competing events: transplant, waitlist death, delisting, or alive on waitlist. Multivariable competing risk regression analysis was performed to determine predictors of waitlist death/delisting. Posttransplant survival was analyzed using Kaplan-Meier methods.

RESULTS

Among 187 patients listed, 82% (153 of 187) underwent LTx (median time-to-transplant, 2.0 mo), whereas 16% (30 of 187) died or were delisted (median time-to-event, 1.6 mo). At 90 d, 6 mo, and 12 mo after listing, 51%, 63%, and 78% of patients had been transplanted, whereas 10%, 14%, and 16% had died or were delisted. Multivariable predictors of waitlist death/delisting were: blood group O compared to A (subdistribution hazard ratio [SHR]: 6.43, P < 0.001), shorter height (per 1 cm, SHR: 1.11, P < 0.001), hospitalization at listing (SHR: 3.98, P = 0.002), and reduced 6-min-walk test distance (per 50 m, SHR: 1.28, P = 0.001). Among LTx recipients, 24% (36 of 153) underwent single LTx. Donor lungs were 58% (88 of 153) extended-criteria, inclusive of 24% (37 of 153) circulatory-determined death. Ninety-day and 1-, 3-, and 5-y retransplant free survival were 97% ± 1%, 92% ± 2%, 81% ± 4%, and 69% ± 6%.

CONCLUSIONS

Patients with ILD require a rapid transit to LTx after listing. Despite this, the vast majority of ILD patients in this study reached LTx with excellent early and midterm outcomes.

Impacts of single nucleotide polymorphisms in Fc gamma receptor IIA (rs1801274) on lung transplant outcomes among Japanese lung transplant recipients

This study aimed to analyze the influences of single nucleotide polymorphisms (SNPs) in Fc gamma receptor IIA (FCGR2A) on postoperative outcomes after lung transplantation (LTx). We enrolled 191 lung transplant recipients (80 undergoing living-donor lobar lung transplants [LDLLTs] and 111 undergoing deceased-donor lung transplants [DDLTs]) in this study. We identified SNPs in FCGR2A (131 histidine [H] or arginine [R]; rs1801274) and reviewed the infectious complication-free survival after ICU discharge. The SNPs in FCGR2A comprised H/H (n=53), H/R (n=24), and R/R (n=3) in LDLLT, and H/H (n=67), H/R (n=42), and R/R (n=2) in DDLT. Recipients with H/H (H/H group) and those with H/R or R/R (R group) were compared in the analyses of infectious complications. In multivariate analyses, the R group of SNPs in FCGR2A was associated with pneumonia-free survival (HR: 2.52 [95% confidence interval {CI}: 1.35-4.71], p=0.004), fungal infection-free survival (HR: 2.50 [95% CI: 1.07-5.84], p=0.035), and cytomegalovirus infection-free survival (HR: 2.24 [95% CI: 1.07-4.69], p=0.032) in LDLLT but it was not associated with infectious complication-free survival in DDLT. Therefore, in LDLLT, more attention to infectious complications might need to be paid for LTx recipients with H/R or R/R than for those with H/H.

Imaging Course of Lung Transplantation: From Patient Selection to Postoperative Complications

Lung transplant is increasingly performed for the treatment of end-stage lung disease. As the number of lung transplants and transplant centers continues to rise, radiologists will more frequently participate in the care of patients undergoing lung transplant, both before and after transplant. Potential donors and recipients undergo chest radiography and CT as part of their pretransplant assessment to evaluate for contraindications to transplant and to aid in surgical planning. After transplant, recipients undergo imaging during the postoperative hospitalization and also in the long-term outpatient setting. Radiologists encounter a wide variety of conditions leading to end-stage lung disease and a myriad of posttransplant complications, some of which are unique to lung transplantation. Familiarity with these pathologic conditions, including their imaging findings and their temporal relationship to the transplant, is crucial to accurate radiologic interpretation. Knowledge of the surgical techniques and expected postoperative appearance prevents confusing normal posttransplant imaging findings with complications. A basic understanding of the indications, contraindications, and surgical considerations of lung transplant aids in imaging interpretation and protocoling and also facilitates communication between radiologists and transplant physicians. Despite medical and surgical advances over the past several decades, lung transplant recipients currently have an average posttransplant life expectancy of only 6.7 years. As members of the transplant team, radiologists can help maximize patient survival and hopefully increase posttransplant life expectancy and quality of life in the coming decades. ^©RSNA, 2021 An invited commentary by Bierhals is available online. Online supplemental material is available for this article.

The influence of the native lung on early outcomes and survival after single lung transplantation

Objective

To determine whether problems arising in the native lung may influence the short-term outcomes and survival after single lung transplantation (SLT), and therefore should be taken into consideration when selecting the transplant procedure.

Patients and methods

Retrospective review of 258 lung transplants performed between June 2012 and June 2019. Among them, 161 SLT were selected for the analysis. Complications in the native lung were recorded and distributed into two groups: early and late complications (within 30 days or after 30 days post-transplant). Donor and recipient preoperative factors, 30-day mortality and survival were analysed and compared between groups by univariable and multivariable analyses, and adjusting for transplant indication.

Results

There were 161 patients (126M/35F; 57±7 years) transplanted for emphysema (COPD) (n = 72), pulmonary fibrosis (IPF) (n = 77), or other indications (n = 12). Forty-nine patients (30%) presented complications in the native lung. Thirty-day mortality did not differ between patients with or without early complications (6% vs. 12% respectively; p = 0.56). Twelve patients died due to a native lung complication (7.4% of patients; 24% of all deaths). Survival (1,3,5 years) without vs. with late complications: COPD (89%, 86%, 80% vs. 86%, 71%, 51%; p = 0.04); IPF (83%, 77%, 72% vs. 93%, 68%, 58%; p = 0.65). Among 30-day survivors: COPD (94%, 91%, 84% vs. 86%, 71%, 51%; p = 0.01); IPF (93%, 86%, 81% vs. 93%, 68%, 58%; p = 0.19). Native lung complications were associated to longer ICU stay (10±17 vs. 33±96 days; p<0.001), longer postoperative intubation (41±85 vs. 99±318 hours; p = 0.006), and longer hospital stay (30±24 vs. 45±34 days; p = 0.03). The presence of late native lung problems predicted survival in COPD patients (OR: 2.55; p = 0.07).

Conclusion

The native lung is a source of morbidity in the short-term and mortality in the long-term after lung transplantation. This should be taken into consideration when choosing the transplant procedure, especially in COPD patients.

Challenges, experiences, and postoperative outcomes in setting up first successful lung transplant unit in India

Background

Lung transplantation (LT) has emerged as a definitive cure for a plethora of end-stage lung diseases (ESLDs). With improvements in immune-suppression protocols, the posttransplantation survival rates have gone up.

Aim

The study reported the initial experience of the India's single largest lung transplant program on clinicopathological profile, procedures, challenges encountered, and outcomes.

Settings and Design

A retrospective analysis was done from data available at three centers of Institute of Heart and Lung Transplant, Gleneagles Global Hospitals across Chennai, Bengaluru, and Mumbai.

Materials and Methods

A total of 132 patients underwent lung (single or bilateral) or combined heart and lung transplant between April 2017 and March 2020. All the participants had 30 days' follow-up. Postoperative complications, graft rejection, and 30-day mortality were reported. Kaplan-Meier survival analysis and logistic regression analysis were performed.

Statistical Analysis Used

Kaplan-Meier survival and binary logistic regression was performed.

Results

Interstitial lung diseases, 65.91%, were the most common diagnosis. Bilateral LT (81.3%) was the most common type of LT performed. Grade III primary graft dysfunction was observed in 16 (12.1%). Distal airway stenosis (21.97%) was the most common complication followed by anastomotic stenosis (14.30%). Gram-negative bacterial sepsis (52%) was the leading cause of death. Cumulative probability of survival at 1 month was 0.85 (95% confidence interval [CI] 0.80-0.92), and at 1 year, it was 0.78 (95% CI, 0.72-0.86).

Conclusion

This study establishes the fact that despite multiple challenges, LT is a viable option for selected patients with ESLDs in India and should encourage early referrals to a transplant center.

Distinct molecular and immunological properties of circulating exosomes isolated from pediatric lung transplant recipients with bronchiolitis obliterans syndrome - a retrospective study

Long-term success following human lung transplantation is poor due to chronic rejection. We demonstrated circulating exosomes of lung origin during acute and chronic lung allograft rejection. We analyzed plasma from pediatric lung transplant recipients (LTxRs) enrolled in the CTOT-C-03 to determine whether circulating exosomes are released into circulation during bronchiolitis obliterans syndrome (BOS). Plasma exosomes were isolated, and human leukocyte antigens (HLA) were detected. Exosomes were analyzed for lung self-antigens (SAgs), co-stimulatory molecules transcription factors, major histocompatibility complex class II (MHC-II), adhesion molecules, and 20S proteasome. Mice were immunized with exosomes from BOS or stable to determine their immunogenicity. Circulating exosomes from BOS LTxRs contained increased levels of SAgs, donor HLA class I, MHC-II, transcription factors, co-stimulatory molecules, and 20S proteasome compared with stable. Serial analysis of exosomes containing SAgs demonstrated that exosomes are detectable in the circulation before BOS. Mice immunized with exosomes from BOS, or stable, demonstrated that exosomes from BOS are distinct in inducing both humoral and cellular immune responses to SAgs. Circulating exosomes from BOS LTxRs elicit distinct humoral and cellular response. In addition, detection of SAgs on circulatory exosomes 12 months before diagnosis of BOS suggest that exosomes could serve as biomarker.

Pediatric lung transplantation in the largest lung transplantation center of China: embarking on a long road

Lung transplantation (LT) has been an effective treatment for carefully selected children with end-stage lung diseases. The aim of this retrospective study is to introduce our experience at the largest LT center in Wuxi, China and to compare the outcomes of pediatric LT between children with idiopathic pulmonary arterial hypertension (IPAH) and other end-stage lung diseases. Ten pediatric patients undergoing LT from 2007 to 2019 were included. Sequential bilateral lung transplantation (BLT) with bilateral anterior thoracotomies was performed in all patients, seven of whom also underwent reduced size LT. Eight children survived until the end of our follow-up period on July 31st, 2019, with the longest survival of 11 years. Extracorporeal membrane oxygenation (ECMO) was intraoperatively used in all IPAH children and one non-IPAH child. Left heart function of IPAH children, though initially compromised, recovered after surgery. Statistically significant differences in operation time and post-operative mechanical ventilation between IPAH group and non-IPAH group were observed without discernible impact on post-LT survival. Pediatric LT appears to be a safe treatment for IPAH children to improve longevity and quality of life and ECMO may help reduce the risk of surgery and the postoperative complications.

Single versus bilateral lung transplantation in idiopathic pulmonary fibrosis: A systematic review and meta-analysis

Objective

Lung transplantation remains the only curative treatment for end-stage lung disease, conferring a better survival for some IPF patients, but whether they should receive double lung transplantation (DLT) or single lung transplantation (SLT) is still controversial. The aim of this study was to determine which type of lung transplantation was more effective and relatively safe in IPF patients by meta-analysis.

Methods

Publications comparing overall survival (OS) or other perioperative characteristics between IPF patients undergoing SLT and DLT were selected from electronic databases. The hazard ratios (HRs) were abstracted or calculated to evaluate the survival outcome. Odds ratios (ORs) or mean differences (MDs) were used to compare the causes of death or perioperative parameters. A random-effect model was used to combine data. Heterogeneity was quantified by means of an I² with 95% confidence interval (95% CI). The publication bias was estimated using the Eggers test with Begg’s funnel plots.

Results

16 studies with 17,872 IPF cases who met the inclusion criteria were included in this meta-analysis. SLT was associated with declined post-transplant FEV1% (MD = -15.37, 95% CI:-22.28,-8.47; P<0.001), FVC % (MD = -12.52, 95% CI:-19.45,-5.59; P<0.001) and DLCO% (MD = -13.85, 95% CI:-20.42,-7.29; P<0.001), but no significant advantage of DLT over SLT was seen in the overall survival outcome (HR = 1.08, 95% CI: 0.91–1.29; P = 0.391). Subgroup analyses for studies of follow-up period ≥ 60 months also showed similar results (all P-values>0.05). Moreover, there was fewer deaths attributable to primary graft dysfunction in SLT recipients (OR = 0.31, 95% CI: 0.2–0.48; P<0.001), while more patients with SLT died of malignancy (OR = 3.44, 95% CI: 2.06–5.77; P<0.001).

Conclusion

Our findings suggest that DLT was associated with better postoperative pulmonary function, but there was no difference in long-term overall survival between patients undergoing DLT and SLT. However, further high-quality and large-scale studies are needed to confirm these findings.