Safety and utility of indwelling pleural catheters in lung transplant recipients.

INTRODUCTION: The safety and efficacy of indwelling pleural catheters (IPCs) in lung allograft recipients is under-reported. METHODS: We performed a multicenter, retrospective analysis between 1/1/2010 and 6/1/2022 of consecutive IPCs placed in lung transplant recipients. Outcomes included incidence of infectious and non-infectious complications and rate of auto-pleurodesis. RESULTS: Seventy-one IPCs placed in 61 lung transplant patients at eight centers were included. The most common indication for IPC placement was recurrent post-operative effusion. IPCs were placed at a median of 59 days (IQR 40-203) post-transplant and remained for 43 days (IQR 25-88). There was a total of eight (11%) complications. Infection occurred in five patients (7%); four had empyema and one had a catheter tract infection. IPCs did not cause death or critical illness in our cohort. Auto-pleurodesis leading to the removal of the IPC occurred in 63 (89%) instances. None of the patients in this cohort required subsequent surgical decortication. CONCLUSIONS: The use of IPCs in lung transplant patients was associated with an infectious complication rate comparable to other populations previously studied. A high rate of auto-pleurodesis was observed. This work suggests that IPCs may be considered for the management of recurrent pleural effusions in lung allograft recipients.

Fulminant lung fibrosis in non-resolvable COVID-19 requiring transplantation.

BACKGROUND: Coronavirus Disease 2019 (COVID-19) can lead to the development of acute respiratory distress syndrome (ARDS). In some patients with non-resolvable (NR) COVID-19, lung injury can progress rapidly to the point that lung transplantation is the only viable option for survival. This fatal progression of lung injury involves a rapid fibroproliferative response and takes on average 15 weeks from initial symptom presentation. Little is known about the mechanisms that lead to this fulminant lung fibrosis (FLF) in NR-COVID-19. METHODS: Using a pre-designed unbiased PCR array for fibrotic markers, we analyzed the fibrotic signature in a subset of NR-COVID-19 lungs. We compared the expression profile against control lungs (donor lungs discarded for transplantation), and explanted tissue from patients with idiopathic pulmonary fibrosis (IPF). Subsequently, RT-qPCR, Western blots and immunohistochemistry were conducted to validate and localize selected pro-fibrotic targets. A total of 23 NR-COVID-19 lungs were used for RT-qPCR validation. FINDINGS: We revealed a unique fibrotic gene signature in NR-COVID-19 that is dominated by a hyper-expression of pro-fibrotic genes, including collagens and periostin. Our results also show a significantly increased expression of Collagen Triple Helix Repeat Containing 1(CTHRC1) which co-localized in areas rich in alpha smooth muscle expression, denoting myofibroblasts. We also show a significant increase in cytokeratin (KRT) 5 and 8 expressing cells adjacent to fibroblastic areas and in areas of apparent epithelial bronchiolization. INTERPRETATION: Our studies may provide insights into potential cellular mechanisms that lead to a fulminant presentation of lung fibrosis in NR-COVID-19. FUNDING: National Institute of Health (NIH) Grants R01HL154720, R01DK122796, R01DK109574, R01HL133900, and Department of Defense (DoD) Grant W81XWH2110032 to H.K.E. NIH Grants: R01HL138510 and R01HL157100, DoD Grant W81XWH-19-1-0007, and American Heart Association Grant: 18IPA34170220 to H.K.-Q. American Heart Association: 19CDA34660279, American Lung Association: CA-622265, Parker B. Francis Fellowship, 1UL1TR003167-01 and The Center for Clinical and Translational Sciences, McGovern Medical School to X.Y.

Pediatric lung transplantation for COVID-19: Unique clinical and psychosocial barriers.

BACKGROUND: SARS-CoV-2 infection in the age group of 0-17 years contributes to approximately 22% of all laboratory-confirmed SARS-CoV-2 infections. Fortunately, this age group has a lower death rate (0.5 per 100 000) that accounts for only 4% of the total deaths due to COVID-19. Despite the low mortality rate in the pediatric population, children of minority groups represented 78% of the deaths highlighting the existing disparities in access to health care. METHODS: With the emergence of the more contagious COVID-19 variants and the relatively slow pace of vaccination among the pediatric population, it is possible to see more cases of significant lung injury and potential for transplantation for the younger age group. RESULTS: To our knowledge, our patient is the youngest to have undergone lung transplantation for SARS-CoV-2. CONCLUSION: The case presented unique challenges, particularly in relation to timing for listing and psychosocial support for parents who were his decision makers.

Trends in marginal lung allograft survival: Advanced-age donors improve.

INTRODUCTION: Although lung demand continues to outpace supply, 75% of potential donor lungs are discarded without being transplanted in the United States. To identify the discarded cohorts best suited to alleviate the lung shortage and reduce waitlist mortality, we explored changes in survival over time for five marginal donor definitions: age >60 years, smoking history >20 pack-years, PaO2 /FiO2  < 300 mmHg, purulent bronchoscopic secretions, and chest radiograph infiltrates. METHODS: Our retrospective cohort study separated 27 803 lung recipients in the UNOS Database into three 5-year eras by transplant date: 2005-2009, 2010-2014, and 2015-2019. Multivariable Cox proportional hazards regression and Kaplan-Meier analysis with log-rank test were used to compare survival across the eras. RESULTS: Three definitions-low PaO2 /FiO2 , purulent bronchoscopic secretions, and abnormal chest radiographs-did not bear out as truly marginal, demonstrating lack of significantly elevated risk. Advanced donor age demonstrated considerable survival improvement (HR (95% CI): 1.47 (1.26-1.72) in 2005-2009 down to 1.14 (.97-1.35) for 2015-2019), with protective factors being recipients <60 years, moderate recipient BMI, and low Lung Allocation Score (LAS). Donors with smoking history failed to demonstrate any significant improvement (HR (95% CI): 1.09 (1.01-1.17) in 2005-2009 increasing to 1.22 (1.08-1.38) in 2015-2019). CONCLUSIONS: Advanced donor age, previously the most significant risk factor, has improved to near-benchmark levels, demonstrating the possibility for matching older donors to healthier non-elderly recipients in selected circumstances. Low PaO2 /FiO2 , bronchoscopic secretions, and abnormal radiographs demonstrated survival on par with standard donors. Significant donor smoking history, a moderate risk factor, has failed to improve.

Power washing pulmonary alveolar proteinosis.

Pulmonary alveolar proteinosis is an uncommon cause of insidious onset shortness of breath and hypoxemia. It is caused by an accumulation of surfactant within the alveoli. Left untreated, it can be fatal. Standard-of-care treatment is whole-lung lavage; however, in severe cases, the associated hypoxemia can be profound and single-lung ventilation would not be tolerated, potentially preventing a lifesaving treatment. Single cases using veno-venous extracorporeal membrane oxygenation to perform whole-lung lavage have been reported. Here we describe three patients with severe pulmonary alveolar proteinosis who were successfully treated with whole-lung lavage using veno-venous extracorporeal membrane oxygenation for oxygenation support.

Allograft discard risk index for lung transplantation.

BACKGROUND: The demand for donor lungs continues to outpace the supply, yet nearly 75% of donor lungs intended for lung transplantation are discarded. METHODS: We reviewed all donation after brain death organ donors listed within the UNOS Deceased Donor Database between 2005 and 2020. Univariable and multivariable analyses were run on the training set (n = 69,355) with the primary outcome defined as lung discard, and the results were used to create a discard risk index (DSRI). Discard data were assessed at DSRI value deciles using the validation set (n = 34,670), and differences in 1-year mortality were assessed using stratum-specific likelihood ratio (SSLR) analysis. RESULTS: Donor factors most associated with higher DSRI values included age > 65, PaO2 < 300, hepatitis C virus, and cigarette use. Factors associated with lower DSRI values included donor age < 40 and PaO2 > 400. The DSRI was a reliable predictor of donor discard, with a C-statistic of 0.867 in the training set and 0.871 in the validation set. The DSRI was not a reliable predictor of 30-day, 1-year, 3-year, and 5-year survival following transplantation (C-statistic 0.519-0.530). SSLR analysis resulted in three 1-year mortality strata (SSLR 0.88 in the 1st DSRI value decile, 1.03 in the 2nd-5th, & 1.19 in the 6th-10th). CONCLUSIONS: The factors leading to lung allograft discard are not the same as those leading to worse recipient outcomes. This suggests that with proper allocation, many of the grafts that are now commonly discarded could be used in the future donor pool with limited impact on mortality.

The Effect of Obstructive Sleep Apnea on 3-Year Outcomes in Patients Who Underwent Orthotopic Heart Transplantation.

Despite the well-known association between obstructive sleep apnea (OSA) and cardiovascular disease, there is a paucity of data regarding OSA in orthotopic heart transplant (OHT) recipients and its effect on clinical outcomes. Hence, we sought to determine the association between OSA, as detected by polysomnography, and late graft dysfunction (LGD) after OHT. In this retrospective review of consecutive OHT recipients from 2012 to 2014 at our center, we examined LGD, i.e., graft failure >1 year after OHT, through competing risks analysis. Due to small sample size and event counts, as well as preliminary testing which revealed statistically similar demographics and outcomes, we pooled patients who had treated OSA with those who had no OSA. Of 146 patients, 29 (20%) had untreated OSA, i.e., OSA without use of continuous positive airway pressure therapy, at the time of transplantation. Patients with untreated OSA were significantly older, heavier, and more likely to have baseline hypertension than those with treated/no OSA. Although there were no differences between groups in regard to short-term complications of acute kidney injury, cardiac allograft vasculopathy, or primary graft dysfunction, there were significant differences in the occurrence of LGD. Those with untreated OSA were at 3 times the risk of developing LGD than those with treated/no OSA (hazard ratio 3.2; 95% confidence interval 1.3 to 7.9; p = 0.01). Because OSA is a common co-morbidity of OHT patients and because patients with untreated OSA have an elevated risk of LGD, screening for and treating OSA should occur during the OHT selection period.