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.

Robotic Lobectomy Is Cost-effective and Provides Comparable Health Utility Scores to Video-assisted Lobectomy: Early Results of the RAVAL Trial.

OBJECTIVE: The aim of this study was to determine if robotic-assisted lobectomy (RPL-4) is cost-effective and offers improved patient-reported health utility for patients with early-stage non-small cell lung cancer when compared with video-assisted thoracic surgery lobectomy (VATS-lobectomy). BACKGROUND: Barriers against the adoption of RPL-4 in publicly funded health care include the paucity of high-quality prospective trials and the perceived high cost of robotic surgery. METHODS: Patients were enrolled in a blinded, multicentered, randomized controlled trial in Canada, the United States, and France, and were randomized 1:1 to either RPL-4 or VATS-lobectomy. EuroQol 5 Dimension 5 Level (EQ-5D-5L) was administered at baseline and postoperative day 1; weeks 3, 7, 12; and months 6 and 12. Direct and indirect costs were tracked using standard methods. Seemingly Unrelated Regression was applied to estimate the cost effect, adjusting for baseline health utility. The incremental cost-effectiveness ratio was generated by 10,000 bootstrap samples with multivariate imputation by chained equations. RESULTS: Of 406 patients screened, 186 were randomized, and 164 analyzed after the final eligibility review (RPL-4: n=81; VATS-lobectomy: n=83). Twelve-month follow-up was completed by 94.51% (155/164) of participants. The median age was 68 (60-74). There were no significant differences in body mass index, comorbidity, pulmonary function, smoking status, baseline health utility, or tumor characteristics between arms. The mean 12-week health utility score was 0.85 (0.10) for RPL-4 and 0.80 (0.19) for VATS-lobectomy ( P =0.02). Significantly more lymph nodes were sampled [10 (8-13) vs 8 (5-10); P =0.003] in the RPL-4 arm. The incremental cost/quality-adjusted life year of RPL-4 was $14,925.62 (95% CI: $6843.69, $23,007.56) at 12 months. CONCLUSION: Early results of the RAVAL trial suggest that RPL-4 is cost-effective and associated with comparable short-term patient-reported health utility scores when compared with VATS-lobectomy.

Laparoscopic Toupet fundoplication: a safe and effective anti-reflux option in lung transplant recipients.

BACKGROUND: Fundoplication is known to improve allograft outcomes in lung transplant recipients by reducing retrograde aspiration secondary to gastroesophageal reflux disease, a modifiable risk factor for chronic allograft dysfunction. Laparoscopic Nissen fundoplication has historically been the anti-reflux procedure of choice, but the procedure is associated with discernable rates of postoperative dysphagia and gas-bloat syndrome. Laparoscopic Toupet fundoplication, an alternate anti-reflux surgery with lower rates of foregut complications in the general population, is the procedure of choice on our institution's lung transplant protocol. In this work, we evaluated the efficacy and safety of laparoscopic Toupet fundoplication in our lung transplant recipients. METHODS: A prospective case series of 44 lung transplant recipients who underwent laparoscopic Toupet fundoplication by a single surgeon between September 2018 and November 2020 was performed. Preoperative and postoperative results from 24-h pH, esophageal manometry, gastric emptying, and pulmonary function studies were collected alongside severity of gastroesophageal reflux disease and other gastrointestinal symptoms. RESULTS: Median DeMeester score decreased from 25.9 to 5.4 after fundoplication (p < 0.0001), while percentage of time pH < 4 decreased from 7 to 1.1% (p < 0.0001). The severity of heartburn and regurgitation were also reduced (p < 0.0001 and p = 0.0029 respectively). Overall, pulmonary function, esophageal motility, gastric emptying, severity of bloating, and dysphagia were not significantly different post-fundoplication than pre-fundoplication. Patients with decreasing rates of FEV1 pre-fundoplication saw improvement in their rate of change of FEV1 post-fundoplication (p = 0.011). Median follow-up was 32.2 months post-fundoplication. CONCLUSIONS: Laparoscopic Toupet fundoplication provides objective pathologic acid reflux control and symptomatic gastroesophageal reflux improvement in lung transplant recipients while preserving lung function and foregut motility. Thus, laparoscopic Toupet fundoplication is a safe and effective antireflux surgery alternative in lung transplant recipients.

A prospective examination of swallow and cough dysfunction after lung transplantation.

OBJECTIVES: Swallow and cough dysfunction are possible surgical complications of lung transplantation (LT). We examined voluntary cough strength, sensorimotor reflexive cough integrity, and swallow-related respiratory rate (RR) across swallowing safety and aspiration response groups in recovering LT recipients. METHODS: Forty-five LT recipients underwent flexible endoscopic evaluation of swallowing indexed by the validated Penetration Aspiration Scale. RR before and after a 3-ounce water drinking task was measured. Voluntary and reflexive cough screening were performed to index motor and sensory outcomes. T-tests, one-way ANOVAs, and chi-square (odds ratios) were used. RESULTS: 60% of patients exhibited laryngeal penetration (n = 27) and 40% demonstrated tracheal aspiration (n = 18); 72% (n = 13) demonstrated silent aspiration. Baseline RR was higher in aspirators versus non-aspirators (26.5 vs. 22.6, p = 0.04) and in silent aspirators compared to non-silent aspirators (27.9 vs. 20.7, p = 0.01). RR change post-swallowing did not differ between aspiration response groups; however, it was significantly higher in aspirators compared to non-aspirators (3 vs. -2, p = 0.02). Compared to non-silent aspirators, silent aspirators demonstrated reduced voluntary cough peak expiratory flow (PEF; 166 vs. 324 L/min, p = 0.01). PEF, motor and urge to cough reflex cough ratings did not differ between aspirators and non-aspirators. Silent aspirators demonstrated a 7.5 times higher odds of failing reflex cough screening compared to non-silent aspirators (p = 0.07). CONCLUSIONS: During the acute recovery period, all LT participants demonstrated some degree of unsafe swallowing and reduced voluntary cough strength. Silent aspirators exhibited elevated RR, reduced voluntary cough physiologic capacity to defend the airway, and a clinically distinguishable blunted motor response to reflex cough screening.

Incidence, risk factors, and sequelae of dysphagia mediated aspiration following lung transplantation.

BACKGROUND: We aimed to determine dysphagia profiles before and after lung transplantation (prevalence, incidence) and to examine predictors and health-related outcomes of aspiration in individuals undergoing lung transplantation. METHODS: A retrospective single-center study of consecutive adults undergoing lung transplantation and completing a postoperative videofluoroscopic swallowing study between 2017 and 2020 was conducted. The validated penetration aspiration scale indexed swallowing safety and clinical outcomes were extracted from electronic medical records. T-tests, chi square with odds ratios, and multivariable logistic regression were conducted. RESULTS: Two hundred five participants were identified who underwent lung transplantation and a postoperative swallowing exam. Of those who underwent both a pre- and postoperative swallowing exam (n = 170), preoperatively 83% demonstrated safe swallowing and 17% unsafe swallowing. Following lung transplantation, 16% demonstrated safe swallowing and 84% demonstrated unsafe swallowing (39% penetration, 45% aspiration). Independent predictors of postoperative aspiration were venous-venous extracorporeal membrane oxygenation (odds ratio [OR]: 6.7, confidence interval [CI]: 2.0-81.5) and reintubation (OR: 4.5, CI: 1.0-60.3), p < .05. Compared to non-aspirators, aspirators demonstrated higher odds of being discharged to a dependent care setting (OR: 2.3, CI: 1.2-4.5), p < .05. Aspirators spent significantly longer NPO (median = 138.0 hours, 25th percentile, 75th percentile = 75.7, 348.3) compared to non-aspirators (median = 85.0 hours, 25th percentile, 75th percentile = 48.0, 131.6, p < .001). CONCLUSIONS: Pre-existing dysphagia was low in this cohort of patients undergoing lung transplantation, however increased approximately 5-fold following lung transplantation and was associated with increased morbidity.

Inpatient Management of the Acutely Decompensating Lung Transplant Candidate.

Lung allocation in the US changed nearly 15 years ago from time accrued on the waiting list to disease severity and likelihood of posttransplant survival, represented by the lung allocation score (LAS). Notably, the risk of death within a year plays a stronger role on the score calculation than posttransplant survival. While this change was associated with the intended decrease in waitlist mortality (most recently reported at 14.6%), it was predictable that transplant teams would have to care for increasingly older and complex candidates and recipients. This urgency-based allocation also led centers to routinely consider transplanting patients with higher acuity, often hospitalized and, not infrequently, in the intensive care unit (ICU). According to the Scientific Registry for Transplant Recipients, from 2009 to 2019, the proportion of lung recipients hospitalized and those admitted to the ICU at the time of transplant increased from 18.9% to 26.8% and from 9.2% to 16.5%, respectively..

RAVAL trial: Protocol of an international, multi-centered, blinded, randomized controlled trial comparing robotic-assisted versus video-assisted lobectomy for early-stage lung cancer.

BACKGROUND: Retrospective data demonstrates that robotic-assisted thoracoscopic surgery provides many benefits, such as decreased postoperative pain, lower mortality, shorter length of stay, shorter chest tube duration, and reductions in the incidence of common postoperative pulmonary complications, when compared to video-assisted thoracoscopic surgery. Despite the potential benefits of robotic surgery, there are two major barriers against its widespread adoption in thoracic surgery: lack of high-quality prospective data, and the perceived higher cost of it. Therefore, in the face of these barriers, a prospective randomized controlled trial comparing robotic- to video-assisted thoracoscopic surgery is needed. The RAVAL trial is a two-phase, international, multi-centered, blinded, parallel, randomized controlled trial that is comparing robotic- to video-assisted lobectomy for early-stage non-small cell lung cancer that has been enrolling patients since 2016. METHODS: The RAVAL trial will be conducted in two phases: Phase A will enroll 186 early-stage non-small cell lung cancer patients who are candidates for minimally invasive pulmonary lobectomy; while Phase B will continue to recruit until 592 patients are enrolled. After consent, participants will be randomized in a 1:1 ratio to either robotic- or video-assisted lobectomy, and blinded to the type of surgery they are allocated to. Health-related quality of life questionnaires will be administered at baseline, postoperative day 1, weeks 3, 7, 12, months 6, 12, 18, 24, and years 3, 4, 5. The primary objective of the RAVAL trial is to determine the difference in patient-reported health-related quality of life outcomes between the robotic- and video-assisted lobectomy groups at 12 weeks. Secondary objectives include determining the differences in cost-effectiveness, and in the 5-year survival data between the two arms. The results of the primary objective will be reported once Phase A has completed accrual and the 12-month follow-ups are completed. The results of the secondary objectives will be reported once Phase B has completed accrual and the 5-year follow-ups are completed. DISCUSSION: If successfully completed, the RAVAL Trial will have studied patient-reported outcomes, cost-effectiveness, and survival of robotic- versus video-assisted lobectomy in a prospective, randomized, blinded fashion in an international setting. TRIAL REGISTRATION: ClinicalTrials.gov, NCT02617186. Registered 22-September-2015. https://clinicaltrials.gov/ct2/show/NCT02617186.

Lung transplantation for acute exacerbation of interstitial lung disease.

BACKGROUND: Acute exacerbations of interstitial lung diseases (AE-ILD) have a high mortality rate with no effective medical therapies. Lung transplantation is a potentially life-saving option for patients with AE-ILD, but its role is not well established. The aim of this study is to determine if this therapy during AE-ILD significantly affects post-transplant outcomes in comparison to those transplanted with stable disease. METHODS: We conducted a retrospective study of consecutive patients with AE-ILD admitted to our institution from 2015 to 2018. The comparison group included patients with stable ILD listed for lung transplant during the same period. The primary end-points were in-hospital mortality for patients admitted with AE-ILD and 1-year survival for the transplanted patients. RESULTS: Of 53 patients admitted for AE-ILD, 28 were treated with medical therapy alone and 25 underwent transplantation. All patients with AE-ILD who underwent transplantation survived to hospital discharge, whereas only 43% of the AE-ILD medically treated did. During the same period, 67 patients with stable ILD underwent transplantation. Survival at 1 year for the transplanted patients was not different for the AE-ILD group versus stable ILD group (96% vs 92.5%). The rates of primary graft dysfunction, post-transplant hospital length-of-stay and acute cellular rejection were similar between the groups. CONCLUSION: Patients with ILD transplanted during AE-ILD had no meaningful difference in overall survival, rate of primary graft dysfunction or acute rejection compared with those transplanted with stable disease. Our results suggest that lung transplantation can be considered as a therapeutic option for selected patients with AE-ILD.

Case report: double lung en bloc procurement from a donor after arterial switch operation.

The growing unmet demand for suitable organ donors increases each year. Despite relative contraindications for thoracic organ donation after previous cardiac surgery, experienced programmes and surgeons can successfully utilise the lungs from select donors who have undergone prior cardiac surgery. This is the first reported case of double lung en bloc procurement from a donor who had a previous arterial switch operation as an infant.

Effects of Patient and Surgery Characteristics on Persistent Postoperative Pain: A Mediation Analysis.

OBJECTIVE: Acute postoperative pain intensity is associated with persistent postsurgical pain (PPP) risk. However, it remains unclear whether acute postoperative pain intensity mediates the relationship between clinical factors and persistent pain. MATERIALS AND METHODS: Participants from a mixed surgical population completed the Brief Pain Inventory and Pain Catastrophizing Scale before surgery, and the Brief Pain Inventory daily after surgery for 7 days and at 30 and 90 days after surgery. We considered mediation models using the mean of the worst pain intensities collected daily on each of postoperative days (PODs) 1 to 7 against outcomes of worst pain intensity at the surgical site endpoints reflecting PPP (POD 90) and subacute pain (POD 30). RESULTS: The analyzed cohort included 284 participants for the POD 90 outcome. For every unit increase of maximum acute postoperative pain intensity through PODs 1 to 7, there was a statistically significant increase of mean POD 90 pain intensity by 0.287 after controlling for confounding effects. The effects of female versus male sex (m=0.212, P=0.034), pancreatic/biliary versus colorectal surgery (m=0.459, P=0.012), thoracic cardiovascular versus colorectal surgery (m=0.31, P=0.038), every minute increase of anesthesia time (m=0.001, P=0.038), every unit increase of preoperative average pain score (m=0.012, P=0.015), and every unit increase of catastrophizing (m=0.044, P=0.042) on POD 90 pain intensity were mediated through acute PODs 1 to 7 postoperative pain intensity. DISCUSSION: Our results suggest the mediating relationship of acute postoperative pain on PPP may be predicated on select patient and surgical factors.

Ex vivo SARS-CoV-2 infection of human lung reveals heterogeneous host defense and therapeutic responses.

Cell lines are the mainstay in understanding the biology of COVID-19 infection but do not recapitulate many of the complexities of human infection. The use of human lung tissue is one solution for the study of such novel respiratory pathogens. We hypothesized that a cryopreserved bank of human lung tissue would allow for the ex vivo study of the interindividual heterogeneity of host response to SARS-CoV-2, thus providing a bridge between studies with cell lines and studies in animal models. We generated a cryobank of tissues from 21 donors, many of whom had clinical risk factors for severe COVID-19. Cryopreserved tissues preserved 90% cell viability and contained heterogenous populations of metabolically active epithelial, endothelial, and immune cell subsets of the human lung. Samples were readily infected with HCoV-OC43 and SARS-CoV-2 and demonstrated comparable susceptibility to infection. In contrast, we observed a marked donor-dependent heterogeneity in the expression of IL6, CXCL8, and IFNB1 in response to SARS-CoV-2. Treatment of tissues with dexamethasone and the experimental drug N-hydroxycytidine suppressed viral growth in all samples, whereas chloroquine and remdesivir had no detectable effect. Metformin and sirolimus, molecules with predicted but unproven antiviral activity, each suppressed viral replication in tissues from a subset of donors. In summary, we developed a system for the ex vivo study of human SARS-CoV-2 infection using primary human lung tissue from a library of donor tissues. This model may be useful for drug screening and for understanding basic mechanisms of COVID-19 pathogenesis.

In vivo reprogramming of pathogenic lung TNFR2+ cDC2s by IFNß inhibits HDM-induced asthma.

Asthma is a common inflammatory lung disease with no known cure. Previously, we uncovered a lung TNFR2+ conventional DC2 subset (cDC2s) that induces regulatory T cells (Tregs) maintaining lung tolerance at steady state but promotes TH2 response during house dust mite (HDM)-induced asthma. Lung IFNß is essential for TNFR2+ cDC2s-mediated lung tolerance. Here, we showed that exogenous IFNß reprogrammed TH2-promoting pathogenic TNFR2+ cDC2s back to tolerogenic DCs, alleviating eosinophilic asthma and preventing asthma exacerbation. Mechanistically, inhaled IFNß, not IFNα, activated ERK2 signaling in pathogenic lung TNFR2+ cDC2s, leading to enhanced fatty acid oxidation (FAO) and lung Treg induction. Last, human IFNß reprogrammed pathogenic human lung TNFR2+ cDC2s from patients with emphysema ex vivo. Thus, we identified an IFNß-specific ERK2-FAO pathway that might be harnessed for DC therapy.

Early outcomes after lung transplantation for severe COVID-19: a series of the first consecutive cases from four countries.

BACKGROUND: Lung transplantation is a life-saving treatment for patients with end-stage lung disease; however, it is infrequently considered for patients with acute respiratory distress syndrome (ARDS) attributable to infectious causes. We aimed to describe the course of disease and early post-transplantation outcomes in critically ill patients with COVID-19 who failed to show lung recovery despite optimal medical management and were deemed to be at imminent risk of dying due to pulmonary complications. METHODS: We established a multi-institutional case series that included the first consecutive transplants for severe COVID-19-associated ARDS known to us in the USA, Italy, Austria, and India. De-identified data from participating centres-including information relating to patient demographics and pre-COVID-19 characteristics, pretransplantation disease course, perioperative challenges, pathology of explanted lungs, and post-transplantation outcomes-were collected by Northwestern University (Chicago, IL, USA) and analysed. FINDINGS: Between May 1 and Sept 30, 2020, 12 patients with COVID-19-associated ARDS underwent bilateral lung transplantation at six high-volume transplant centres in the USA (eight recipients at three centres), Italy (two recipients at one centre), Austria (one recipient), and India (one recipient). The median age of recipients was 48 years (IQR 41-51); three of the 12 patients were female. Chest imaging before transplantation showed severe lung damage that did not improve despite prolonged mechanical ventilation and extracorporeal membrane oxygenation. The lung transplant procedure was technically challenging, with severe pleural adhesions, hilar lymphadenopathy, and increased intraoperative transfusion requirements. Pathology of the explanted lungs showed extensive, ongoing acute lung injury with features of lung fibrosis. There was no recurrence of SARS-CoV-2 in the allografts. All patients with COVID-19 could be weaned off extracorporeal support and showed short-term survival similar to that of transplant recipients without COVID-19. INTERPRETATION: The findings from our report show that lung transplantation is the only option for survival in some patients with severe, unresolving COVID-19-associated ARDS, and that the procedure can be done successfully, with good early post-transplantation outcomes, in carefully selected patients. FUNDING: National Institutes of Health. VIDEO ABSTRACT.

Slow Dynamics of Acute Postoperative Pain Intensity Time Series Determined via Wavelet Analysis Are Associated With the Risk of Severe Postoperative Day 30 Pain.

BACKGROUND: Evidence suggests that increased early postoperative pain (POP) intensities are associated with increased pain in the weeks following surgery. However, it remains unclear which temporal aspects of this early POP relate to later pain experience. In this prospective cohort study, we used wavelet analysis of clinically captured POP intensity data on postoperative days 1 and 2 to characterize slow/fast dynamics of POP intensities and predict pain outcomes on postoperative day 30. METHODS: The study used clinical POP time series from the first 48 hours following surgery from 218 patients to predict their mean POP on postoperative day 30. We first used wavelet analysis to approximate the POP series and to represent the series at different time scales to characterize the early temporal profile of acute POP in the first 2 postoperative days. We then used the wavelet coefficients alongside demographic parameters as inputs to a neural network to predict the risk of severe pain 30 days after surgery. RESULTS: Slow dynamic approximation components, but not fast dynamic detailed components, were linked to pain intensity on postoperative day 30. Despite imbalanced outcome rates, using wavelet decomposition along with a neural network for classification, the model achieved an F score of 0.79 and area under the receiver operating characteristic curve of 0.74 on test-set data for classifying pain intensities on postoperative day 30. The wavelet-based approach outperformed logistic regression (F score of 0.31) and neural network (F score of 0.22) classifiers that were restricted to sociodemographic variables and linear trajectories of pain intensities. CONCLUSIONS: These findings identify latent mechanistic information within the temporal domain of clinically documented acute POP intensity ratings, which are accessible via wavelet analysis, and demonstrate that such temporal patterns inform pain outcomes at postoperative day 30.

Patient and Procedural Determinants of Postoperative Pain Trajectories.

BACKGROUND: The primary goal of this study was to evaluate patterns in acute postoperative pain in a mixed surgical patient cohort with the hypothesis that there would be heterogeneity in these patterns. METHODS: This study included 360 patients from a mixed surgical cohort whose pain was measured across postoperative days 1 through 7. Pain was characterized using the Brief Pain Inventory. Primary analysis used group-based trajectory modeling to estimate trajectories/patterns of postoperative pain. Secondary analysis examined associations between sociodemographic, clinical, and behavioral patient factors and pain trajectories. RESULTS: Five distinct postoperative pain trajectories were identified. Many patients (167 of 360, 46%) were in the moderate-to-high pain group, followed by the moderate-to-low (88 of 360, 24%), high (58 of 360, 17%), low (25 of 360, 7%), and decreasing (21 of 360, 6%) pain groups. Lower age (odds ratio, 0.94; 95% CI, 0.91 to 0.99), female sex (odds ratio, 6.5; 95% CI, 1.49 to 15.6), higher anxiety (odds ratio, 1.08; 95% CI, 1.01 to 1.14), and more pain behaviors (odds ratio, 1.10; 95% CI, 1.02 to 1.18) were related to increased likelihood of being in the high pain trajectory in multivariable analysis. Preoperative and intraoperative opioids were not associated with postoperative pain trajectories. Pain trajectory group was, however, associated with postoperative opioid use (P < 0.001), with the high pain group (249.5 oral morphine milligram equivalents) requiring four times more opioids than the low pain group (60.0 oral morphine milligram equivalents). CONCLUSIONS: There are multiple distinct acute postoperative pain intensity trajectories, with 63% of patients reporting stable and sustained high or moderate-to-high pain over the first 7 days after surgery. These postoperative pain trajectories were predominantly defined by patient factors and not surgical factors.

Successful Preoperative Optimization for Lung Transplantation With Transcatheter Mitral Valve Repair.

Surgically treatable valvular heart disease is common in patients with end-stage lung disease. Nevertheless, advanced lung disease is often seen as a contraindication to cardiac surgery, and severe valvular disease is seen as a contraindication to lung transplantation. This report describes the case of a patient presenting with very severe chronic obstructive pulmonary disease and severe mitral regurgitation who was managed with transcatheter mitral valve repair and who subsequently underwent successful lung transplantation. Critical valvular heart disease in patients with chronic respiratory failure may be amenable to transcatheter therapy, which may favorably affect lung transplantation candidacy.