Ex vivo lung perfusion in donation after circulatory death: A post hoc analysis of the Normothermic Ex Vivo Lung Perfusion as an Assessment of Extended/Marginal Donors Lungs trial.

OBJECTIVE: Donation after circulatory death (DCD) donors offer the ability to expand the lung donor pool and ex vivo lung perfusion (EVLP) further contributes to this ability by allowing for additional evaluation and resuscitation of these extended criteria donors. We sought to determine the outcomes of recipients receiving organs from DCD EVLP donors in a multicenter setting. METHODS: This was an unplanned post hoc analysis of a multicenter, prospective, nonrandomized trial that took place during 2011 to 2017 with 3 years of follow-up. Patients were placed into 3 groups based off procurement strategy: brain-dead donor (control), brain-dead donor evaluated by EVLP, and DCD donors evaluated by EVLP. The primary outcomes were severe primary graft dysfunction at 72 hours and survival. Secondary outcomes included select perioperative outcomes, and 1-year and 3-years allograft function and quality of life measures. RESULTS: The DCD EVLP group had significantly higher incidence of severe primary graft dysfunction at 72 hours (P = .03), longer days on mechanical ventilation (P < .001) and in-hospital length of stay (P = .045). Survival at 3 years was 76.5% (95% CI, 69.2%-84.7%) for the control group, 68.3% (95% CI, 58.9%-79.1%) for the brain-dead donor group, and 60.7% (95% CI, 45.1%-81.8%) for the DCD group (P = .36). At 3-year follow-up, presence observed bronchiolitis obliterans syndrome or quality of life metrics did not differ among the groups. CONCLUSIONS: Although DCD EVLP allografts might not be appropriate to transplant in every candidate recipient, the expansion of their use might afford recipients stagnant on the waitlist a viable therapy.

Changing patterns in lung transplant for respiratory failure due to COVID-19 in the U.S.

Many patients with severe COVID-19 have been affected by acute respiratory distress syndrome, which has been associated with increased mortality, and up to 31% of these survivors had persistent interstitial lung abnormalities with impaired lung function and quality of life even after 6 to 24 months after initial disease. Lung transplantation quickly emerged as a viable therapy for select patients with respiratory failure due to COVID-19 by mid-2020. In this report, we identified 477 patients who underwent lung transplantation for COVID-19 in the U.S. between March 2020 and December 2022. The number of patients waitlisted and undergoing lung transplantation for COVID-19 increased steadily in the early part of the pandemic with a peak of 97 patients waitlisted between October and December 2021, before steadily decreasing since. Notably, the procedure is now increasingly being done for survivors of COVID-19 with pulmonary fibrosis, rather than for refractory ARDS patients. The 1-year post-transplant mortality was 13.7%.

Endotracheal nebulization of gold nanoparticles for noninvasive pulmonary drug delivery.

Background & aims: Gold nanoparticles (AuNPs) are useful tools for noninvasive drug delivery. AuNP nebulization has shown poor deposition results, and AuNP tracking postadministration has involved methods inapplicable to clinical settings. The authors propose an intratracheal delivery method for minimal AuNP loss and computed tomography scans for noninvasive tracking. Materials & methods: Through high-frequency and directed nebulization postendotracheal intubation, the authors treated rats with AuNPs. Results & conclusion: The study showed a dose-dependent and bilateral distribution of AuNPs causing no short-term distress to the animal or risk of airway inflammation. The study demonstrated that AuNPs do not deposit in abdominal organs and show targeted delivery to human lung fibroblasts, offering a specific and noninvasive strategy for respiratory diseases requiring long-term therapies.

This study presents an alternative method for drug delivery involving gold nanoparticle aerosolization directly into the major airways. Direct nebulization prevents particle loss and avoids drug administration through the blood. The particles can be detected successfully via upper body scans, which are noninvasive and allow for on-demand monitoring. Nanoparticles are flexible tools that can be modified to target specific cells of interest and can be excreted upon completion of their function. These results could represent an alternative method of drug administration in patients needing repeated cytotoxic therapies with known off-target effects.

Lung Transplantation for Primary Ciliary Dyskinesia and Kartagener Syndrome: A Multicenter Study.

Primary ciliary dyskinesia, with or without situs abnormalities, is a rare lung disease that can lead to an irreversible lung damage that may progress to respiratory failure. Lung transplant can be considered in end-stage disease. This study describes the outcomes of the largest lung transplant population for PCD and for PCD with situs abnormalities, also identified as Kartagener's syndrome. Retrospectively collected data of 36 patients who underwent lung transplantation for PCD from 1995 to 2020 with or without SA as part of the European Society of Thoracic Surgeons Lung Transplantation Working Group on rare diseases. Primary outcomes of interest included survival and freedom from chronic lung allograft dysfunction. Secondary outcomes included primary graft dysfunction within 72 h and the rate of rejection ≥A2 within the first year. Among PCD recipients with and without SA, the mean overall and CLAD-free survival were 5.9 and 5.2 years with no significant differences between groups in terms of time to CLAD (HR: 0.92, 95% CI: 0.27-3.14, p = 0.894) or mortality (HR: 0.45, 95% CI: 0.14-1.43, p = 0.178). Postoperative rates of PGD were comparable between groups; rejection grades ≥A2 on first biopsy or within the first year was more common in patients with SA. This study provides a valuable insight on international practices of lung transplantation in patients with PCD. Lung transplantation is an acceptable treatment option in this population.

A Unique Cellular Organization of Human Distal Airways and Its Disarray in Chronic Obstructive Pulmonary Disease.

Rationale: Remodeling and loss of distal conducting airways, including preterminal and terminal bronchioles (pre-TBs/TBs), underlie progressive airflow limitation in chronic obstructive pulmonary disease (COPD). The cellular basis of these structural changes remains unknown. Objectives: To identify biological changes in pre-TBs/TBs in COPD at single-cell resolution and determine their cellular origin. Methods: We established a novel method of distal airway dissection and performed single-cell transcriptomic profiling of 111,412 cells isolated from different airway regions of 12 healthy lung donors and pre-TBs of 5 patients with COPD. Imaging CyTOF and immunofluorescence analysis of pre-TBs/TBs from 24 healthy lung donors and 11 subjects with COPD were performed to characterize cellular phenotypes at a tissue level. Region-specific differentiation of basal cells isolated from proximal and distal airways was studied using an air-liquid interface model. Measurements and Main Results: The atlas of cellular heterogeneity along the proximal-distal axis of the human lung was assembled and identified region-specific cellular states, including SCGB3A2+ SFTPB+ terminal airway-enriched secretory cells (TASCs) unique to distal airways. TASCs were lost in COPD pre-TBs/TBs, paralleled by loss of region-specific endothelial capillary cells, increased frequency of CD8+ T cells normally enriched in proximal airways, and augmented IFN-γ signaling. Basal cells residing in pre-TBs/TBs were identified as a cellular origin of TASCs. Regeneration of TASCs by these progenitors was suppressed by IFN-γ. Conclusions: Altered maintenance of the unique cellular organization of pre-TBs/TBs, including loss of the region-specific epithelial differentiation in these bronchioles, represents the cellular manifestation and likely the cellular basis of distal airway remodeling in COPD.

Lung transplant waitlist outcomes among ABO blood groups vary based on disease severity.

BACKGROUND: Blood group O candidates have lower lung transplantation rates despite having the most common blood group. We postulated that waitlist outcomes among these candidates and those with other blood types vary with disease severity and lung allocation score (LAS). METHODS: We performed a retrospective cohort study of 32,772 waitlist candidates using the United Network of Organ Sharing registry from May 2005 to 2020. After identifying an interaction between blood group and LAS, we evaluated the association between blood group and waitlist outcomes within LAS quartiles using unadjusted and adjusted competing risk models. RESULTS: In the lowest LAS quartile, blood group O had a 20% reduced transplantation rate (SHR: 0.80, 95%CI: 0.75-0.85) and higher waitlist death/removal (1.33, 95%CI: 1.15-1.55) compared with group A. Blood group AB had a 52% higher transplantation rate (SHR: 1.52, 95%CI: 1.34-1.73) in the lowest LAS quartile compared with group A. In the highest LAS quartile, there was no difference in transplantation rates between groups O and A. In contrast, group B had a 19% reduced transplantation rate (SHR, 0.81 95%CI: 0.73-0.89) and AB had a 28% reduced transplantation rate (SHR: 0.72, 95%CI: 0.61-0.86) in the highest LAS quartile. Additionally, groups B and AB had increased risk of waitlist death/removal in the highest LAS quartile compared with A (SHR: 1.27, 95%CI: 1.08-1.48; SHR: 1.31, 95%CI: 1.00-1.72). CONCLUSIONS: Waitlist outcomes among ABO blood groups vary depending on illness severity, which is represented by LAS. Blood group O has lower transplantation rates at low LAS while groups B and AB have lower transplantation rates at high LAS.

Outcomes of Heller Myotomy for Esophageal Achalasia: Lessons From a 48-Year Prospective Experience With 4 Different Techniques.

OBJECTIVE: To provide information on long-term outcomes of Heller myotomy for esophageal achalasia with or without an antireflux fundoplication. BACKGROUND: Since the adoption of the Heller myotomy, surgeons have modified the original technique in order to balance the cure of dysphagia and the consequent cardial incontinence. METHODS: Totally, 470 patients underwent primary Heller myotomy between 1955 and 2020. A long abdominal myotomy (AM) was performed in 83 patients, the Ellis limited transthoracic myotomy (TM) in 30, the laparotomic Heller-Dor (L-HD) in 202, the videolaparoscopic Heller-Dor (VL-HD) in 155. The HD was performed under intraoperative manometric assessment. Starting on 1973 these patients underwent a prospective follow-up program of timed lifelong clinical, radiological, endoscopic evaluations. RESULTS: Median follow-up time was 23.06 years [interquantile range (IQR): 15.04-32.06] for AM, 29.22 years (IQR: 13.46-40.17) for TM, 14.85 years (IQR: 11.05-21.56) for L-HD and 7.51 years (IQR: 3.25-9.60) for VL-HD. In AM, relapse of dysphagia occurred in 25/71 (35.21%), in TM in 11/30 (36.66%), in LH-D in 10/201 (4.97%), in VL-HD in 3/155 (1.93%). Erosive-ulcerative esophagitis was diagnosed for AM in 28.16%, for TM in 30%, for L-HD in 8.45%, for VL-HD in 2.58%. Overall, the outcome was satisfactory in 52.11% for AM, 41.9% for TM, 89.05% for L-HD, 96.12% for VL-HD. CONCLUSIONS: The Dor fundoplication drastically reduces postmyotomy gastroesophageal reflux. The Heller-Dor operation is a competitive option for the cure of esophageal achalasia if this operation is performed according to the rules of surgical physiology learned by means of intraoperative manometry.

Survival After Lung Transplantation for Chronic Hypersensitivity Pneumonitis: Results From a Large International Cohort Study.

Repeated exposure to antigens via inhalation is the primary cause of hypersensitivity pneumonitis, a form of interstitial pneumonia. The chronic form of hypersensitivity pneumonitis leads to progressive loss of respiratory function; lung transplantation is the only therapeutic option for chronically ill patients. The ESTS Lung Transplantation Working Group conducted a retrospective multicentred cohort study to increase the body of knowledge available on this rare indication for lung transplantation. Data were collected for every patient who underwent lung transplant for hypersensitivity pneumonitis in participating centres between December 1996 and October 2019. Primary outcome was overall survival; secondary outcome was freedom from chronic lung allograft dysfunction. A total of 114 patients were enrolled from 9 centres. Almost 90% of patients were diagnosed with hypersensitivity pneumonitis before transplantation, yet the antigen responsible for the infection was identified in only 25% of cases. Eighty per cent of the recipients received induction therapy. Survival at 1, 3, and 5 years was 85%, 75%, and 70%, respectively. 85% of the patients who survived 90 days after transplantation were free from chronic lung allograft dysfunction after 3 years. The given study presents a large cohort of HP patients who underwent lung transplants. Overall survival rate is higher in transplanted hypersensitivity pneumonitis patients than in those suffering from any other interstitial lung diseases. Hypersensitivity pneumonitis patients are good candidates for lung transplantation.

One Year Into the Pandemic: Evolving COVID-19 Outcomes in Lung Transplant Recipients, a Single-center Experience.

In the early months of the coronavirus disease 2019 (COVID-19) pandemic, our center reported a mortality rate of 34% in a cohort of 32 lung transplant recipients with COVID-19 between March and May 2020. Since then, there has been evolving knowledge in prevention and treatments of COVID-19. To evaluate the impact of these changes, we describe the clinical presentation, management, and outcomes of a more recent cohort of lung transplant recipients during the second surge and provide a comparison with our first cohort. Methods: We conducted a retrospective cohort study that included all consecutive lung transplant recipients who tested positive for severe acute respiratory syndrome coronavirus 2 between November 2020 and February 28, 2021. We compared baseline demographics and major outcomes between the first- and second-surge cohorts. Results: We identified 47 lung transplant recipients (median age, 60; 51% female) who tested positive for severe acute respiratory syndrome coronavirus 2 between November 2020 and February 28, 2021. The current cohort had a higher proportion of patients with mild disease (34% versus 16%) and fewer patients with a history of obesity (4% versus 25%). Sixty-six percent (n = 31) required hospitalization and were treated with remdesivir (90%) and dexamethasone (84%). Among those hospitalized, 77% (n = 24) required supplemental oxygen, and 22% (n = 7) required invasive mechanical ventilation. The overall 90-d mortality decreased from 34% to 17% from the first cohort to the second (adjusted odds ratio, 0.26; 95% confidence interval, 0.08-0.85; P = 0.026). Conclusions: Although COVID-19-associated mortality rate in lung transplant recipients at our center has decreased over time, COVID-19 continues to be associated with significant morbidity and mortality.

Lung Transplantation for Pulmonary Fibrosis Associated With Hermansky-Pudlak Syndrome. A Single-center Experience.

Hermansky-Pudlak syndrome (HPS) is an autosomal recessive disorder characterized by oculocutaneous albinism, platelet storage defect with resultant bleeding diathesis, and pulmonary fibrosis. The bleeding diathesis associated with HPS had long been considered a contraindication to lung transplantation; consequently, few reports of successful lung transplantation for HPS exist. Methods: In the largest case series on lung transplant for HPS, we describe the characteristics of 11 lung transplant candidates with HPS-related pulmonary fibrosis, and the management and outcomes of 7 patients who underwent lung transplantation. Results: Of the 7 patients transplanted, 30-d survival was 85.7% (6/7). Six patients had at least 2 y of follow-up available with a 1-y survival of 83.3% and a 2-y survival of 83.3% (5/6). The median age at referral was 48 y (range 29-62 y). Eight patients (72.7%) were of Puerto Rican ancestry with confirmed type 1 HPS mutation. Six out of 7 patients received prophylaxis for bleeding diathesis, with a majority receiving desmopressin; 1 patient was administered aminocaproic acid infusion, and another received 2 units of platelets before surgery. Estimated blood loss and the amount of intraoperative blood product administered was highly variable with or without prophylaxis. Median blood loss was 400 mL (range 125-750) and estimated blood products administered was 700 mL (range 490-4043). Conclusions: HPS should not be considered a contraindication for lung transplantation. Although patients with HPS seem to have an increased risk of massive hemorrhage, the risk is unpredictable. Transplant teams should prepare a preoperative plan in consultation with hematology and consider the use of prophylactic platelet transfusion and desmopressin.

Malakoplakia Presenting as a Lung Mass in a Lung Transplant Recipient: Case Report.

Lung nodules or masses due to a variety of malignant or benign conditions such as opportunistic infections are observed after lung transplant. Malakoplakia is a rare complication in immunocompromised patients. Here we describe the clinical course and management of a lung transplant recipient with pulmonary malakoplakia and provide a review of the literature. To our knowledge, this is the first report of a case of pulmonary malakoplakia due to Escherichia coli infection in a lung allograft.

Bronchoscopic Lobar Lavage in the Treatment of a Single Lung Transplant Recipient With Pulmonary Alveolar Proteinosis: A Case Report.

Pulmonary alveolar proteinosis is a rare disorder that results from impaired clearance of surfactant. There are few case reports in lung transplant recipients. We report the case of a 57-year-old man with chronic hypersensitivity pneumonitis who underwent left single lung transplantation. Approximately 1 year after transplant, he was diagnosed as having pulmonary alveolar proteinosis by surgical lung biopsy. He was successfully treated with bronchoscopic lobar lavage of his allograft but later was diagnosed as having peritoneal mesothelioma. We highlight the challenges in the diagnosis, discuss potential etiologies, and describe a unique therapy of this rare disorder in lung transplant recipients.

Risk Factors and Outcomes for Gastroparesis After Lung Transplantation.

BACKGROUND: Gastroparesis is common after lung transplantation and is associated with worse transplant outcomes, including the development of chronic lung allograft dysfunction (CLAD). This study sought to identify the prevalence, risk factors, and outcomes associated with a new diagnosis of gastroparesis after lung transplantation. METHODS: This was a single-center retrospective study of patients who underwent lung transplantation in 2008-2018. The primary outcome was a new diagnosis of gastroparesis within 3 years of transplant. Secondary outcomes included a new diagnosis of gastroesophageal reflux and the association between gastroparesis and both post-transplant survival and CLAD-free survival. Multivariable logistic regression was used to compare diagnosis of gastroparesis and gastroesophageal reflux, while multivariable Cox proportional hazards models were used to analyze gastroparesis and post-transplant outcomes. RESULTS: Of 616 patients with no prior history of gastroparesis, 107 (17.4%) were diagnosed with delayed gastric emptying within 3 years of transplant. On multivariable logistic regression, black race (OR 2.16, 95% CI 1.18-3.98, p = 0.013) was significantly associated with a new diagnosis of gastroparesis. Age, sex, history of diabetes, connective tissue disease, type of transplant, diagnosis group, renal function, and body mass index were not predictive of gastroparesis post-transplant. Gastroparesis was significantly associated with CLAD (HR 1.76, 95% CI 1.20-2.59, p = 0.004), but not with overall mortality (HR 1.16, p = 0.43). CONCLUSION: While gastroparesis is common after lung transplantation, it remains difficult to predict which patients will develop these complications post-transplant. Black patients were more likely to be diagnosed with gastroparesis after adjusting for relevant confounders. Gastroparesis is associated with increased risk of CLAD, and further studies are needed to assess whether early detection and treatment can reduce the incidence of CLAD.

Identification of Lung Transplant Recipients With a Survival Benefit After Fundoplication.

BACKGROUND: Gastroesophageal reflux disease (GERD) and aspiration of enteric contents are associated with worse outcomes after lung transplantation. The purpose of this study was to elucidate populations of patients who benefit the most from fundoplication after lung transplantation. METHODS: Lung transplantations from 2001 to 2019 (n = 971) were retrospectively reviewed and stratified by fundoplication before (n = 128) or after (n = 24) chronic lung allograft dysfunction (CLAD) development vs patients who did not undergo fundoplication. Patients with a fundoplication before CLAD were propensity matched to patients without a fundoplication. The primary outcome of interest was posttransplant survival. Time-to-event rates were calculated using a multivariable Cox proportional hazards model and Kaplan-Meier functions. RESULTS: Fundoplication before CLAD improved posttransplant survival before and after propensity matching, and it remained a significant predictor after adjusting for baseline characteristics (hazard ratio [HR],0.57; 95 % confidence interval [CI], 0.4 to 0.8; P = .001). Transplant recipients with a restrictive disorder (HR, 0.46; 95 % CI, 0.3 to 0.73; P = .001), age younger than 65 years (HR, 0.48; 95 % CI, 0.32 to 0.71; P < ;0.001), and with both single (HR, 0.47; 95 % CI, 0.28 to 0.79; P = .005) and double (HR, 0.55; 95 % CI, 0.32 to 0.93; P = .027) lung transplants had a significant decrease in mortality after fundoplication. The effect was present after excluding early deaths and CLAD diagnoses. Gastroesophageal reflux disease diagnosed by pH, impedance, or esophagogastroduodenoscopy was not associated with worse outcomes. Among patients with CLAD, a fundoplication was an independent predictor of post-CLAD survival (HR, 0.27; 95 % CI; 0.12 to 0.61; P = .002). CONCLUSIONS: Fundoplication before or after CLAD development is an independent predictor of survival. Younger patients with restrictive disease, independent of the type of transplant, have a survival benefit. Gastroesophageal reflux disease diagnosed by conventional methods was not associated with worse survival.

The Safety and Efficacy of Tracheostomy in Patients Diagnosed With COVID-19: An Analysis of 143 Patients at a Major NYC Medical Center.

OBJECTIVE: To determine the optimal surgical strategy for performing tracheostomy in COVID-19 patients. BACKGROUND: Many ventilated COVID-19 patients require prolonged ventilation. We do not know if tracheostomy will improve their care. Given the paucity of data on this topic, the optimal surgical approach has yet to be elucidated. METHODS: This is a cohort study of 143 ventilator dependent COVID-19 patients undergoing tracheostomy at an academic medical center from April 15th to May 15th, 2020, with follow up until June 1, 2020. We included adult patients admitted to a NYC medical center with COVID-19 who required invasive mechanical ventilation for greater than 2 weeks who were unable to be extubated and determined to have reasonable chance of recovery and fit defined tracheostomy candidate criteria. Patients underwent either a percutaneous tracheostomy (PT) or open surgical tracheostomy (ST) performed by 1 of 3 surgical services. RESULTS: One hundred forty-three patients underwent tracheostomy, 58 (41%) via a ST, and 85 (59%) via a PT. There were no significant differences in patient characteristics between the 2 groups, except that more patients who had a history of extracorporeal membrane oxygenation underwent PT (11% vs 2%, P = 0.049). There were no statistical differences observed between the PT and ST groups with regard to bleeding complications (3.5%vs 10.3%, P = 0.099), tracheostomy related complications (5.9% vs 8.6%, P = 0.528), inpatient death (12% vs 5%, P = 0.178), discharge from hospital (39% vs 36%, P = 0.751) or surgeon illness (0% vs 0%, P = 1). CONCLUSION AND RELEVANCE: The rapid formation of a multi-disciplinary team allows for the efficient evaluation and performance of a large volume of tracheostomies in a resource-limited setting. Bedside tracheostomy in COVID-19 does not cause additional harm to patients if performed after 2 weeks from intubation. It also seems to be safe for proceduralists to perform in this timeframe. The manner of tracheostomy does not change outcomes significantly if it is performed safely and efficiently.

Extracorporeal life support as a bridge to pulmonary retransplantation: prognostic factors for survival in a multicentre cohort analysis.

OBJECTIVES: Pulmonary retransplant (ReTx) is considered a controversial procedure. Despite literature reporting outcomes following ReTx, limited data exist in recipients bridged to their ReTx on extracorporeal life support (ECLS). The goal of this study was to investigate the outcomes of recipients bridged to a first-time ReTx by ECLS. METHODS: We performed a retrospective multicentre cohort analysis from 10 centres in Europe, Asia and North America. The primary outcome was overall survival. Risk factors were analysed using Cox regression models. RESULTS: ECLS as a bridge to a first-time ReTx was performed in 50 recipients (ECLS-ReTx). During the study period, 210 recipients underwent a first-time ReTx without bridging on ECLS (regular-ReTx) and 4959 recipients had a primary pulmonary transplant (index-Tx). The overall 1-year (55%) and 5-year (29%) survival was significantly worse for the ECLS-ReTx group.Compared to the index-Tx group, the mortality risk was significantly higher after ECLS-ReTx [hazard ratio 2.76 (95% confidence interval 1.94-3.91); P < 0.001] and regular-ReTx [hazard ratio 1.65 (95% confidence interval 1.36-2); P < 0.001].In multivariable analysis, recipient age ≥35 years, time interval <1 year from index-Tx, primary graft dysfunction as transplant indication, venoarterial-extracorporeal membrane oxygenation and Zurich donor score ≥4 points were significant risk factors for mortality in ECLS-ReTx recipients. CONCLUSIONS: Recipients for ECLS-ReTx should be carefully selected. Risk factors, such as recipient age, intertransplant interval, primary graft dysfunction as transplant indication and type of ECLS should be kept in mind before bridging these patients on ECLS to ReTx.

Geographic disparities in lung transplantation in the United States before and after the November 2017 allocation change.

BACKGROUND: The primary lung allocation unit was expanded from the donation service area to a 250-mile radius in 2017. Prior to the change, geographic disparities in donor lung availability impacted waitlist outcomes. We sought to determine if the new allocation system improved these disparities. METHODS: We conducted a retrospective cohort study comparing the 2-year period before and after the change. Donor lung availability was defined as the ratio of donor lungs to waitlist candidates in the primary allocation unit. Transplant centers were divided into quartiles by donor lung availability. Multivariable competing risk models were used to determine the association between lung availability and waitlist outcomes. Multivariable Cox proportional hazards models compared post-transplant survival. RESULTS: Prior to the allocation change, the unadjusted transplant rate at centers in the lowest and highest quartiles was 132 and 607 transplants per 100 waitlist years. Candidates in the lowest quartile of donor lung availability had a 61% adjusted lower transplantation rate compared to candidates in highest quartile (sub-hazard ratio [sHR]: 0.39, 95% confidence interval [CI]: 0.34-0.44). After the allocation change, the disparity decreased resulting in an unadjusted transplant rate of 141 and 309 among centers in the lowest and highest quartiles. Candidates in the lowest quartile had a 38% adjusted lower transplantation rate compared to those in the highest (sHR: 0.62, 95% CI: 0.57-0.68). There was no significant difference in 1-year post-transplant survival. CONCLUSIONS: Although the expansion of the primary allocation unit improved disparities in waitlist outcomes without any change in post-transplant survival, there still remain significant differences due to geography.