The Fate of Patients on the Waiting List for Lung Transplantation in Korea

Outcomes of patients awaiting lung transplantation after the implementation of donation after brain death at a single Chinese center

Voluntary contribution has become the only source of donor lungs in China since 2015. To elaborate the outcomes of patients awaiting lung transplantation (LTx) after the implementation of donation after brain death, we performed a retrospective study that encompassed 205 patients with end-stage lung disease who registered for LTx at Shanghai Pulmonary Hospital from January 1, 2015 to January 1, 2021. A total of 180 patients were enrolled in the study. The median waiting time was 1.25 months. Interstitial lung disease (ILD) (103/180, 57.2%) and chronic obstructive pulmonary disease (COPD) (56/180, 31.1%) were the most common diseases in our study population. The mean pulmonary artery pressure (mPAP) of patients in the died-waiting group was higher than that of the survivors (53.29±21.71 mmHg vs. 42.11±18.58 mmHg, P=0.002). The mortality of patients with ILD (34/103, 33.00%) was nearly twice that of patients with COPD (10/56, 17.86%) while awaiting LTx (P=0.041). In the died-waiting group, patients with ILD had a shorter median waiting time than patients with COPD after being listed (0.865 months vs. 4.720 months, P=0.030). ILD as primary disease and mPAP > 35 mmHg were two significant independent risk factors for waitlist mortality, with hazard ratios (HR) of 3.483 (95% CI 1.311-9.111; P=0.011) and 3.500 (95% CI 1.435-8.536; P=0.006). Hence, LTx is more urgently needed in patients with ILD and pulmonary hypertension.

Mortality risk factors in patients on waiting list for lung transplantation between 2005 and 2018: A single institutional experience

BACKGROUND

Lung transplantation is a therapeutic option for patients with end-stage lung disease. However, the increase in organ demand has surpassed the number of donors, with many patients unable to outlive the long waiting period. This study aimed to assess mortality and its risk factors in patients on the waiting list for lung transplantation in a single medical centre.

METHODS

All evaluated clinical and laboratory data of the patients with end-stage lung disease assessed for lung transplantation between February 2005 and November 2018 in National Taiwan University Hospital were recorded in the waiting list database. The patients in this study were divided into two groups: survival and death groups.

RESULTS

Between February 2005 and November 2018, 169 patients were enrolled in the waiting list. Thirty-one patients were alive and waiting for the chance of lung transplantation, 56 underwent lung transplantation, and 82 died while waiting. The mean age of all patients was 43.7 years, and 91 were women. The mean body mass index (BMI) was 20.3. The most common blood type was type O. All patients were in New York Heart Association (NYHA) class III or IV. After analysis of the two groups, lower BMI presented as a mortality factor.

CONCLUSION

This is the first Taiwanese study to describe the mortality factors in patients waiting for lung transplantation. The main factors influencing the survival of these patients were lower BMI, NYHA class IV, and diseases which cause end-stage lung diseases (infection and pulmonary fibrosis).

Lung transplant programs in developing countries: challenges, solutions, and outcomes

PURPOSE OF REVIEW

The majority of lung transplants (LT) performed are in developed countries. In contrast, little is known about the status of LT in developing nations. The objective is to summarize the challenges, present solutions, and review outcomes of LT in developing countries. We hope this review will guide healthcare providers in such countries that are contemplating embarking on this journey.

RECENT FINDINGS

The key challenges that programs in developing countries encountered included shortage and marginal quality of donated organs, lack of dedicated multi-disciplinary LT team, limited availability of advanced technology and high risk of post-transplant infections. Education and collaboration among government, public, and healthcare sectors was seen as fundamental to building and maintaining a successful program. Despite minimal resources and huge challenges, LT survival rates in developing countries improved and were comparable with outcomes reported by the International Society for Heart and Lung Transplantation (ISHLT) Registry.

SUMMARY

Starting a new LT program is a daunting task that is complex and resource intensive, especially in developing countries. Improving outcomes indeed provide impetus to continue to persevere in this endeavor with support from all sectors. The findings presented here could help new programs to better anticipate and tackle challenges.

Association of Chest CT-Based Quantitative Measures of Muscle and Fat with Post-Lung Transplant Survival and Morbidity: A Single Institutional Retrospective Cohort Study in Korean Population

OBJECTIVE

Abnormal body composition is an important modifiable risk factor in lung transplantation. Therefore, precise quantification of different body components, including muscle and fat, may play an important role in optimizing outcomes in lung transplant patients. The purpose of the study was to investigate the prognostic significance of muscle and subcutaneous fat mass measured on chest CT with regard to lung transplantation survival and other post-transplant outcomes.

MATERIALS AND METHODS

The study population included 45 consecutive adult lung transplant recipients (mean age of 47.9 ± 12.1 years; 31 males and 14 females) between 2011 and 2017. Preoperative cross-sectional areas of muscle and subcutaneous fat were semi-automatically measured on axial CT images at the level of the 12th thoracic vertebra (T12). Additional normalized indexed parameters, adjusted for either height or weight, were obtained. Associations of quantitative parameters with survival and various other post-transplant outcomes were evaluated.

RESULTS

Of the 45 patients included in the present study, 10 mortalities were observed during the follow-up period. Patients with relative sarcopenia (RS) classified based on height-adjusted muscle area with a cut-off value of 28.07 cm²/m² demonstrated worse postoperative survival (log-rank test, p = 0.007; hazard ratio [HR], 6.39:1) despite being adjusted for age, sex, and body mass index (HR, 8.58:1; p = 0.022). Weight-adjusted parameters of muscle area were negatively correlated with duration of ventilator support (R = -0.54, p < 0.001) and intensive care unit (ICU) stay (R = -0.33, p = 0.021).

CONCLUSION

Patients with RS demonstrate worse survival after lung transplantation that those without RS. Additionally, quantitative parameters of muscles measured at the T12 level on chest CT were associated with the duration of post-lung transplant ventilator support and duration of stay in the ICU.

High-flow nasal cannula oxygen therapy to treat acute respiratory failure in patients with acute exacerbation of idiopathic pulmonary fibrosis

Background:

Some patients with idiopathic pulmonary fibrosis (IPF) develop acute exacerbation (AE-IPF) leading to severe acute respiratory failure (ARF); despite conventional supportive therapy, the mortality rate remains extremely high. The aim of this study was to assess how a treatment algorithm incorporating high-flow nasal cannula (HFNC) oxygen therapy affects the short-term mortality of patients with AE-IPF who develop ARF.

Method and design:

A retrospective cohort analysis was conducted.

Patients and interventions:

The study consisted of 17 patients with AE-IPF admitted to a respiratory intensive care unit (RICU) for ARF managed using a treatment algorithm incorporating HFNC. The outcome measure was mortality rate during their stay in the RICU.

Results:

Implementation of the treatment algorithm led to a successful outcome in nine patients and to a negative one in eight patients (47.1%) who died within 39 days of being admitted to the RICU. The survival rate was 70.6% (±0.1 %) at 15 days, 52.9% (±0.1%) at 30 days, 35.3% (±0.1%) at 90 days, and 15.6% (±9.73 %) at 365 days. Overall, 4 out of 10 patients who did not respond to conventional oxygen therapy showed a satisfactory response to HFNC.

Conclusions:

Short-term mortality fell to below 50% when a treatment algorithm incorporating HFNC was implemented in a group of patients with AE-IPF admitted to a RICU for ARF. Patients not responding to conventional oxygen therapy seemed to benefit from HFNC.

The reviews of this paper are available via the supplementary material section.

The therapy of idiopathic pulmonary fibrosis: what is next?

Idiopathic pulmonary fibrosis (IPF) is a chronic, progressive, fibrosing interstitial lung disease, characterised by progressive scarring of the lung and associated with a high burden of disease and early death. The pathophysiological understanding, clinical diagnostics and therapy of IPF have significantly evolved in recent years. While the recent introduction of the two antifibrotic drugs pirfenidone and nintedanib led to a significant reduction in lung function decline, there is still no cure for IPF; thus, new therapeutic approaches are needed. Currently, several clinical phase I-III trials are focusing on novel therapeutic targets. Furthermore, new approaches in nonpharmacological treatments in palliative care, pulmonary rehabilitation, lung transplantation, management of comorbidities and acute exacerbations aim to improve symptom control and quality of life. Here we summarise new therapeutic attempts and potential future approaches to treat this devastating disease.

Underutilization of potential donors for lung transplantation at a tertiary care center in North India

Objective:

Lung transplantation is infrequently performed in India due to several constraints, and whether the poor lung transplantation rates in India are due to a lack of eligible lung donors is unclear. In this study, we explored the availability of donors for lung transplantation.

Materials and Methods:

This was a retrospective analysis of all brain-dead participants who underwent assessment of eligibility for lung donation between August 2015 and June 2018. All participants underwent a detailed clinical evaluation that included history, physical examination, arterial blood gas analysis, chest radiograph, and bronchoscopy. The final eligibility for lung donation was assessed using the existing “ideal” criteria and the less stringent “extended” criteria.

Results:

A total of 55 brain-dead participants (41 [74.5%] males) were assessed for eligibility for lung donation. The mean (standard deviation [SD]) age of the participants was 38.4 (17.2) years. The mean (SD) duration of prior invasive mechanical ventilation at the time of assessment was 4 (3.1) days, with a mean (SD) partial pressure of arterial oxygen: inspired oxygen fraction ratio (PaO₂:FiO₂) of 326.6 (153.5). The proportion of participants who were found suitable for lung donation was 16 (29.1%) and 35 (63.6%) on employing the ideal and the extended criteria, respectively. Inadequate oxygenation status, abnormal chest radiograph, and sepsis were the most common reasons for excluding participants using either criteria. Despite the availability of adequate lung donors, only one lung transplantation could be performed.

Conclusion:

Even with the most stringent criteria for lung assessment, nearly one-third of the brain-dead participants had lungs suitable for lung transplantation. Lack of eligible lung donors is not a reason for the poor lung transplantation rates in India.

Adult lung transplantation case-volume and in-hospital and long-term mortality in Korea

Background

The inverse relationship between case-volume and surgical mortality has been reported in complex surgical procedures. The aim of this study was to evaluate the effect of case-volume on mortality after lung transplantation in Korea.

Methods

The National Health Insurance Service data was used to analyse all adult lung transplantations in Korea between 2007 and 2016. Institutions were categorized into low-volume (< 5 lung transplantations/year) centers or high-volume (≥ 5 lung transplantations/year) centers. Risk-adjusted in-hospital mortality and long-term survival according to case-volume was evaluated.

Results

A total of 315 adult recipients underwent lung transplantation at 7 centers. The odds ratio for in-hospital mortality in low-volume centers was similar to high-volume centers (OR, 1.496; 95% CI, 0.81–2.76; p = 0.197). Log-rank analysis of Kaplan-Meier curves according to case-volume also did not show a difference in long-term survival between high- and low-volume centers (p = 0.052).

Conclusions

There was no association between case-volume and in-hospital mortality after lung transplantation in Korea, although there was a tendency towards better long-term survival associated with high-volume centers.

Patient characteristics and outcome of end-stage lung diseases referred for lung transplantation in North India

Objective:

Most countries worldwide have transplant registries for patients with end-stage lung diseases (ESLD) requiring lung transplantation. There is no such lung transplant registry in India. Herein, we describe the demographic profile and clinical outcomes among patients referred for lung transplantation at a tertiary care center in North India.

Materials and Methods:

This was a prospective, observational study of consecutive patients with chronic respiratory diseases who were referred for lung transplantation between July 2013 and December 2016. Patients were evaluated using standard criteria for listing for lung transplantation.

Results:

Of the 176 patients assessed for lung transplantation, 167 were included in the study. The mean (standard deviation [SD]) age of the study population (52.1% females) was 53.2 (14.7) years. Interstitial lung disease (ILD, 46.7%), chronic obstructive pulmonary disease (COPD, 25.7%), and bronchiectasis (10.2%) were the most common diseases in this population. The median (interquartile range, IQR) survival was worst for patients with bronchiolitis (78.5 [9–208] days) and idiopathic pulmonary fibrosis (IPF, 93.5 [19–239] days) and best for patients with idiopathic pulmonary arterial hypertension (757 [340–876] days) and COPD (578 [184–763] days). Only 13% of the patients expressed willingness for lung transplantation. Patients willing for transplantation died earlier than those unwilling (median [IQR], 102 [36-224] days vs. 310 [41-713] days, P < 0.001).

Conclusion:

ILD was the most common cause of ESLD in patients referred for lung transplantation. The waitlist mortality was highest for patients with bronchiolitis and IPF. Despite having ESLD, very few patients were willing for lung transplantation. Patients willing for lung transplantation died earlier than those who were unwilling.

Extracorporeal Life Support as a Bridge to Lung Transplantation in Patients With Acute Respiratory Failure

BACKGROUND

Extracorporeal membrane oxygenation (ECMO) is being used more often as a bridge to transplantation (BTT) in patients with acutely decompensated end-stage lung disease in Korea. ECMO as a BTT may be the only rescue strategy for severe acute respiratory failure, but many centers still consider it to be a relative contraindication to lung transplantation because of its poor outcome. Because there are not enough lung donors, it is important to determine their optimal use. We reviewed and analyzed our experiences with the use of ECMO as a BTT in patients with acute respiratory failure.

METHODS

This was a retrospective analysis of all patients with acutely decompensated end-stage lung disease treated with ECMO as a bridge to lung transplantation between March 2012 and February 2016.

RESULTS

Of the 194 patients who underwent respiratory ECMO over a 4-year period, a BTT strategy was used for 19 patients (median age, 58 years) on our institution's lung transplantation waiting list (15 veno-venous, 3 veno-veno-arterial, 1 veno-arterial). Fourteen patients (73.7%) were successfully bridged to transplantation; however, 3 died while on the waiting list and 2 returned to their baseline functions without transplantation. The overall in-hospital survival rate was 57.9% (11 of 19), including the 9 (64.3%) patients who underwent transplantation.

CONCLUSIONS

Our findings support the view that well-selected candidates with acutely decompensated end-stage lung disease may be safely bridged until a suitable donor is identified. ECMO is not able to reverse the course of patients; however, it could be a life-saving option for patients with acute respiratory failure requiring lung transplantation.

Prognostic value of pre-transplant mean pulmonary arterial pressure in lung transplant recipients: a single-institution experience

Background

Currently, lung transplantation (LTX) is considered to be a curative treatment option in patients with end-stage lung disease. Although pulmonary hypertension (PH), confirmed by cardiac catheterization, is a prognostic factor in patients undergoing LTX, the prognostic value of PH in Asian lung transplant recipients remains uncertain. In this study, we aimed to determine whether PH before LTX may serve as a prognostic factor for survival in Asian patients.

Methods

The medical records of 50 patients [male, 27; female, 23; mean age, 51.0 (41.0-60.0) years], who received preoperative right heart catheterization (RHC) and echocardiography before single or double LTX at Severance Hospital between January 2010 and December 2014, were reviewed. The relationship between 1-year survival after LTX and PH [mean pulmonary arterial pressure (mPAP) ≥25 mmHg at rest] was evaluated.

Results

The mean right ventricular systolic pressure and mPAP were 48.5 (22.8) and 30.0 (24.0-40.0) mmHg. Of the 50 patients, 17 (34.0%) died within a year after LTX. The 1-year survival rate among patients with mPAP ≥25 mmHg (58.8%) was lower than the survival rate among patients with mPAP <25 mmHg (87.5%). Pre-transplantation mPAP of ≥25 mmHg was associated with post-transplantation survival [hazard ratio (HR), 4.832; 95% confidence interval (CI), 1.080-21.608, P=0.039]. The presence of preoperative PH was also associated with an increased risk of postoperative complications.

Conclusions

Confirmation of PH via preoperative cardiac catheterization was associated with the prognosis of the patient after LTX. Clinicians should consider the necessity for early transplantation surgery before the mPAP reaches ≥25 mmHg.

Current Status and Future of Lung Donation in Korea

Lung transplantation is the only effective treatment option for patients with end-stage lung disease. However, donor organ shortage makes timely transplant not possible for all patients, especially in Korea. We investigated the number and utilization of donor lungs by retrospectively reviewing all donor organs registered in the Korea Network for Organ Sharing database from March 2012 to March 2016. The donors were stratified into 4 groups by donor acceptability criteria. A total of 1,304 donors were included. Of those, 295 brain-dead donors (22.6%) consented to lung donation. Among these consented donors, 168 donors (12.9%) were retrieved for lung transplant. Retrieval rate was very low compared with that of the kidney (93.9%), liver (86.3%), and heart (27.3%). The characteristics of utilized donor lungs were: mean age, 40.5 years (range: 18 to 63 years); mean partial pressure of oxygen, 356.5 mmHg; mean smoking history, 5.9 pack-years; and mean body mass index, 22.6 kg/m². The proportion of donors with acceptable condition of the transplanted lungs was only 39.3% (ideal 19, standard 47, marginal 70, unusable 32). Among brain-dead patients who denied to donate lungs (n = 1,009), 82 were potentially acceptable donors (ideal 19, standard 63), which was equal to half of actually transplanted lung donations. Many potential donor lungs, which are currently excluded, may be successfully used in lung transplantation in Korea. The available lung donors must be actively selected and managed to maximize the utilization of this precious resource.

Perioperative factors associated with 1-year mortality after lung transplantation: a single-center experience in Korea

Background

Most studies about the risk factors of 1-year mortality after lung transplantation were performed on non-Asians. This study aimed to evaluate the perioperative factors related to the 1-year mortality after lung transplantation in Korea.

Methods

Sixty-eight consecutive patients who underwent lung transplantation without preoperative extracorporeal membrane oxygenation treatment at 1 tertiary hospital in South Korea between October 24, 2012, and October 16, 2015, were analyzed retrospectively.

Results

Forty-four patients (64.7%) lived for >1 year after lung transplantation. The median age of all patients was 55 years (range, 16-75 years), and men accounted for 57.4%. The major cause of lung transplantation was idiopathic pulmonary fibrosis (48.5%); the other causes were interstitial lung disease related to connective tissue disease (17.6%) and bronchiolitis obliterans after stem cell transplantation (14.7%). In univariate analysis, higher median age (52 vs. 61.5 years, P<0.001), male sex (45.5% vs. 79.2%, P=0.007), lower preoperative albumin level (<3 g/dL) (22.7% vs. 45.8%, P=0.049), need for renal replacement therapy (RRT) after surgery (4.5% vs. 37.5%, P=0.001), and postoperative delta neutrophil index (DNI) >5.5 higher than the preoperative DNI (22.7% vs. 70.8%, P<0.001) were significantly related to 1-year mortality. After adjustments, old age, postoperative increased DNI, and need for RRT after transplantation were the independent perioperative risk factors for 1-year mortality after lung transplantation.

Conclusions

Recipients with advanced age should be carefully selected, and patients who need RRT or with increased DNI after transplantation should be managed accordingly.

Effects of intraoperative inhaled iloprost on primary graft dysfunction after lung transplantation: A retrospective single center study

DESIGN

Inhaled iloprost was known to alleviate ischemic-reperfusion lung injury. We investigated whether intraoperative inhaled iloprost can prevent the development of primary graft dysfunction after lung transplantation. Data for a consecutive series of patients who underwent lung transplantation with extracorporeal membrane oxygenation were retrieved. By propensity score matching, 2 comparable groups of 30 patients were obtained: patients who inhaled iloprost immediately after reperfusion of the grafted lung (ILO group); patients who did not receive iloprost (non-ILO group).

RESULTS

The severity of pulmonary infiltration on postoperative days (PODs) 1 to 3 was significantly lower in the ILO group compared to the non-ILO group. The PaO2/FiO2 ratio was significantly higher in the ILO group compared to the non-ILO group (318.2 ± 74.2 vs 275.9 ± 65.3 mm Hg, P = 0.022 on POD 1; 351.4 ± 58.2 vs 295.8 ± 53.7 mm Hg, P = 0.017 on POD 2; and 378.8 ± 51.9 vs 320.2 ± 66.2 mm Hg, P = 0.013 on POD 3, respectively). The prevalence of the primary graft dysfunction grade 3 was lower in the ILO group compared to the non-ILO group (P = 0.042 on POD 1; P = 0.026 on POD 2; P = 0.024 on POD 3, respectively). The duration of ventilator use and intensive care unit were significantly reduced in the ILO group (P = 0.041 and 0.038).

CONCLUSIONS

Intraoperative inhaled iloprost could prevent primary graft dysfunction and preserve allograft function, thus reducing the length of ventilator care and intensive care unit stay, and improving the overall early post-transplant morbidity in patients undergoing lung transplantation.

Rapid porcine lung decellularization using a novel organ regenerative control acquisition bioreactor

To regenerate discarded lungs that would not normally be used for transplant, ex vivo reseeding after decellularization may produce organs suitable for clinical transplantation and therefore close the donor gap. Organ regenerative control acquisition (Harvard Biosciences, Holliston, MA), a novel bioreactor system that simulates physiological conditions, was used to evaluate a method of rapid decellularization. Although most current decellularization methods are 24-72 hours, we hypothesized that perfusing porcine lungs with detergents at higher pressures for less time would yield comparable bioscaffolds suitable for future experimentation. Methods involved perfusion of 1% Triton X-100 (Triton) and 0.1% sodium dodecyl sulfate at varied physiological flow rates. Architecture of native and decellularized lungs was analyzed with hematoxylin and eosin (H&E) staining, transmission electron microscopy (TEM), and scanning electron microscopy (SEM). Dry gas and liquid ventilation techniques were introduced. Our 7 hour decellularization procedure removes nuclear material while maintaining architecture. Bioscaffolds have the microarchitecture for reseeding of stem cells. Hematoxylin and eosin staining suggested removal of nuclear material, whereas SEM and TEM imaging demonstrated total removal of cells with structural architecture preserved. This process can lead to clinical implementation, thereby increasing the availability of human lungs for transplantation.

Lung transplantation in idiopathic pulmonary fibrosis: a systematic review of the literature

BACKGROUND

Idiopathic pulmonary fibrosis (IPF) is a distinct form of interstitial pneumonia with unknown origin and poor prognosis. Current pharmacologic treatments are limited and lung transplantation is a viable option for appropriate patients. The aim of this review was to summarize lung transplantation survival in IPF patients overall, between single (SLT) vs. bilateral lung transplantation (BLT), pre- and post Lung Allocation Score (LAS), and summarize wait-list survival.

METHODS

A systematic review of English-language studies published in Medline or Embase between 1990 and 2013 was performed. Eligible studies were those of observational design reporting survival post-lung transplantation or while on the wait list among IPF patients.

RESULTS

Median survival post-transplantation among IPF patients is estimated at 4.5 years. From ISHLT and OPTN data, one year survival ranged from 75% - 81%; 3-year: 59% - 64%; and 5-year: 47% - 53%. Post-transplant survival is lower for IPF vs. other underlying pre-transplant diagnoses. The proportion of IPF patients receiving BLT has steadily increased over the last decade and a half. Unadjusted analyses suggest improved long-term survival for BLT vs. SLT; after adjustment for patient characteristics, the differences tend to disappear. IPF patients account for the largest proportion of patients on the wait list and while wait list time has decreased, the number of transplants for IPF patients has increased over time. OPTN data show that wait list mortality is higher for IPF patients vs. other diagnoses. The proportion of IPF patients who died while awaiting transplantation ranged from 14% to 67%. While later transplant year was associated with increased survival, no significant differences were noted pre vs. post LAS implementation; however a high LAS vs low LAS was associated with decreased one-year survival.

CONCLUSIONS

IPF accounts for the largest proportion of patients awaiting lung transplants, and IPF is associated with higher wait-list and post-transplant mortality vs. other diagnoses. Improved BLT vs. SLT survival may be the result of selection bias. Survival pre- vs. post LAS appears to be similar except for IPF patients with high LAS, who have lower survival compared to pre-LAS. Data on post-transplant morbidity outcomes are sparse.