Efforts to improve the billing accuracy of robotic-assisted thoracic surgery through education, updated procedure cards, and electronic medical record system changes

Precise medical billing is essential for decreasing hospital liability, upholding environmental stewardship and ensuring fair costs for patients. We instituted a multifaceted approach to improve the billing accuracy of our robotic-assisted thoracic surgery programme by including an educational component, updating procedure cards and removing the auto-populating function of our electronic medical record. Overall, we saw significant improvements in both the number of inaccurate billing cases and, specifically, the number of cases that overcharged patients.

Development and validation of primary graft dysfunction predictive algorithm for lung transplant candidates

BACKGROUND

Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. Accurate prediction of PGD risk could inform donor approaches and perioperative care planning. We sought to develop a clinically useful, generalizable PGD prediction model to aid in transplant decision-making.

METHODS

We derived a predictive model in a prospective cohort study of subjects from 2012 to 2018, followed by a single-center external validation. We used regularized (lasso) logistic regression to evaluate the predictive ability of clinically available PGD predictors and developed a user interface for clinical application. Using decision curve analysis, we quantified the net benefit of the model across a range of PGD risk thresholds and assessed model calibration and discrimination.

RESULTS

The PGD predictive model included distance from donor hospital to recipient transplant center, recipient age, predicted total lung capacity, lung allocation score (LAS), body mass index, pulmonary artery mean pressure, sex, and indication for transplant; donor age, sex, mechanism of death, and donor smoking status; and interaction terms for LAS and donor distance. The interface allows for real-time assessment of PGD risk for any donor/recipient combination. The model offers decision-making net benefit in the PGD risk range of 10% to 75% in the derivation centers and 2% to 10% in the validation cohort, a range incorporating the incidence in that cohort.

CONCLUSION

We developed a clinically useful PGD predictive algorithm across a range of PGD risk thresholds to support transplant decision-making, posttransplant care, and enrich samples for PGD treatment trials.

Validation of a novel donor lung scoring system based on the updated lung Composite Allocation Score

Lung transplantation (LTx) continues to have lower rates of long-term graft survival compared with other organs. Additionally, lung utilization rates from brain-dead donors remain substantially lower compared with other solid organs, despite a growing need for LTx and the significant risk of waitlist mortality. This study aims to examine the effects of using a combination of the recently described novel lung donor (LUNDON) acceptability score and the newly adopted recipient lung Composite Allocation Score (CAS) to guide transplantation. We performed a review of nearly 18 000 adult primary lung transplants from 2015-2022 across the US with retroactive calculations of the CAS value. The medium-CAS group (29.6-34.5) had superior 1-year posttransplant survival. Importantly, the combination of high-CAS (> 34.5) recipients with low LUNDON score (≤ 40) donors had the worst survival at 1 year compared with any other combination. Additionally, we constructed a model that predicts 1-year and 3-year survival using the LUNDON acceptability score and CAS values. These results suggest that caution should be exercised when using marginally acceptable donor lungs in high-priority recipients. The use of the LUNDON score with CAS value can potentially guide clinical decision-making for optimal donor-recipient matches for LTx.

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.

The Society of Thoracic Surgeons Database Analysis: Comparing Sublobar Techniques in Stage IA Lung Cancer

BACKGROUND

This study compares sublobar resections-wedge resection and segmentectomy-in clinical stage IA lung cancers. It tests the hypothesis that overall survival after wedge resection is similar to segmentectomy.

METHODS

Adults undergoing wedge resection or segmentectomy for clinical stage IA lung cancer were identified from The Society of Thoracic Surgeons General Thoracic Surgery Database. Eligible patients were linked to the Centers for Medicare and Medicaid Services database using a matching algorithm. The primary outcome was long-term overall survival. Propensity scores overlap weighting (PSOW) adjustment of wedge resection using validated covariates was used for group difference mitigation. Kaplan-Meier and Cox regression models analyzed survival. All-cause first readmission, and morbidity and mortality were examined using PSOW regression models.

RESULTS

Of 9756 patients, 6141 met inclusion criteria, comprising 2154 segmentectomies and 3987 wedge resections. PSOW reduced differences between the groups. Unadjusted perioperative mortality was comparable, but wedge resection showed lower major morbidity rates. Weighted regression analysis indicated reduced mortality and major morbidity risks in wedge resection. Kaplan-Meier analysis revealed no mortality difference between groups, which was confirmed by PSOW Cox regression models. The cumulative risk of readmission was also comparable for both groups, with Cox Fine-Gray models showing no difference in rehospitalization risks.

CONCLUSIONS

In clinical stage IA lung cancer, relative to segmentectomy, wedge resection has comparable overall survival and lower perioperative morbidity, suggesting it is an equally effective option for the broader population of patients with clinical stage IA lung cancer, not only those at highest risk of complications.

Knowledge gaps in heart and lung donation after the circulatory determination of death: Report of a workshop of the National Heart, Lung, and Blood Institute

In a workshop sponsored by the U.S. National Heart, Lung, and Blood Institute, experts identified current knowledge gaps and research opportunities in the scientific, conceptual, and ethical understanding of organ donation after the circulatory determination of death and its technologies. To minimize organ injury from warm ischemia and produce better recipient outcomes, innovative techniques to perfuse and oxygenate organs postmortem in situ, such as thoracoabdominal normothermic regional perfusion, are being implemented in several medical centers in the US and elsewhere. These technologies have improved organ outcomes but have raised ethical and legal questions. Re-establishing donor circulation postmortem can be viewed as invalidating the condition of permanent cessation of circulation on which the earlier death determination was made and clamping arch vessels to exclude brain circulation can be viewed as inducing brain death. Alternatively, TA-NRP can be viewed as localized in-situ organ perfusion, not whole-body resuscitation, that does not invalidate death determination. Further scientific, conceptual, and ethical studies, such as those identified in this workshop, can inform and help resolve controversies raised by this practice.

Computed Tomography Volumetrics for Size Matching in Lung Transplantation for Restrictive Disease

BACKGROUND

There is no consensus on the optimal allograft sizing strategy for lung transplantation in restrictive lung disease. Current methods that are based on predicted total lung capacity (pTLC) ratios do not account for the diminutive recipient chest size. The study investigators hypothesized that a new sizing ratio incorporating preoperative recipient computed tomographic lung volumes (CTVol) would be associated with postoperative outcomes.

METHODS

A retrospective single-institution study was conducted of adults undergoing primary bilateral lung transplantation between January 2016 and July 2020 for restrictive lung disease. CTVol was computed for recipients by using advanced segmentation software. Two sizing ratios were calculated: pTLC ratio (pTLCdonor/pTLCrecipient) and a new volumetric ratio (pTLCdonor/CTVolrecipient). Patients were divided into reference, oversized, and undersized groups on the basis of ratio quintiles, and multivariable models were used to assess the effect of the ratios on primary graft dysfunction and survival.

RESULTS

CTVol was successfully acquired in 218 of 220 (99.1%) patients. In adjusted analysis, undersizing on the basis of the volumetric ratio was independently associated with decreased primary graft dysfunction grade 2 or 3 within 72 hours (odds ratio, 0.42; 95% CI, 0.20-0.87; P =.02). The pTLC ratio was not significantly associated with primary graft dysfunction. Oversizing on the basis of the volumetric ratio was independently associated with an increased risk of death (hazard ratio, 2.27; 95% CI, 1.04-4.99; P =.04], whereas the pTLC ratio did not have a significant survival association.

CONCLUSIONS

Using computed tomography-acquired lung volumes for donor-recipient size matching in lung transplantation is feasible with advanced segmentation software. This method may be more predictive of outcome compared with current sizing methods, which use gender and height only.

Impact of Diabetes on Pathologic Response to Multimodality Therapy for Esophageal Cancer

BACKGROUND

The incidence of esophageal cancer has increased faster than that of most cancers. Evidence from other malignant neoplasms suggests that diabetic patients have a worse response to multimodality therapy. We hypothesized that diabetic patients with esophageal cancer will have a decreased response to neoadjuvant chemotherapy and radiation therapy compared with nondiabetic patients.

METHODS

A retrospective study of The Society of Thoracic Surgeons General Thoracic Surgery Database identified all patients who had an esophagectomy after neoadjuvant therapy for esophageal cancer between 2012 and 2019. Patients were compared on the basis of the presence of diabetes. A pathologic complete response (pCR) was defined as ypT0 N0. The χ2 and Wilcoxon rank sum tests were used to compare patients' demographic and clinical characteristics between those with and those without diabetes. Multivariable logistic regression was used to evaluate the predictors of response to neoadjuvant therapy.

RESULTS

Of the 9171 patients who met inclusion criteria, 2011 (22%) patients were diabetic and 7160 (78%) patients were nondiabetic. Patients with diabetes were older, more likely to be male, and more likely to have all comorbidities. Univariate analysis revealed that diabetic patients were less likely to have pCR (16% vs 18%; P = .026). Although multivariable analysis showed a trend toward diabetic patients' having lower odds of achieving pCR, diabetes was not independently associated with pCR (odds ratio, 0.89; 95% CI, 0.78-1.01; P = .075).

CONCLUSIONS

Diabetic patients may be less likely than nondiabetic patients to achieve pCR after neoadjuvant treatment of esophageal cancer. This suggests the need for further exploration as diabetic patients with esophageal cancer can potentially benefit from different treatment paradigms compared with their nondiabetic counterparts.

Impact of simultaneous heart procurement on outcomes of donation after circulatory death lung transplantation

Donation after circulatory death (DCD) heart procurement is done using either direct procurement (DP) or thoracoabdominal normothermic machine perfusion (TA-NRP). Both approaches could impact lung transplant outcomes with combined heart and lung procurements from the same donor. The impact of such practice on DCD lung transplant remains unstudied. We performed a retrospective analysis using the United Network for Organ Sharing (UNOS) dataset, identifying DCD lung transplants where the donor also donated the heart (cardia lung donor [CD]). A cohort of noncardiac DCD lung donors (noncardiac lung donor [NCD]) from the same era, matched for donor and recipient characteristics, was used as a comparison group. Both immediate and long-term outcomes were examined. A subanalysis was performed comparing the distinct impact of DP or TA-NRP on DCD lung transplant outcomes. Overall graft survival did not significantly differ between CD and NCD. However, recipients in the CD group trended toward a lower P/F ratio at 72 hours (CD vs NCD: 284 vs 3190; P = .054). In the subanalysis, we identified 40 DP donors and 22 TA-NRP donors. We found the both cohorts had lower P/F ratio at 72 hours than the NCD control (P = .04). Overall, 1-year graft survival was equivalent among the TA-NRP, DP, and NCD cohorts.

The Impact of Donor Smoking on Primary Graft Dysfunction and Mortality after Lung Transplantation

Rationale: Primary graft dysfunction (PGD) is the leading cause of early morbidity and mortality after lung transplantation. Prior studies implicated proxy-defined donor smoking as a risk factor for PGD and mortality. Objectives: We aimed to more accurately assess the impact of donor smoke exposure on PGD and mortality using quantitative smoke exposure biomarkers. Methods: We performed a multicenter prospective cohort study of lung transplant recipients enrolled in the Lung Transplant Outcomes Group cohort between 2012 and 2018. PGD was defined as grade 3 at 48 or 72 hours after lung reperfusion. Donor smoking was defined using accepted thresholds of urinary biomarkers of nicotine exposure (cotinine) and tobacco-specific nitrosamine (4-[methylnitrosamino]-1-[3-pyridyl]-1-butanol [NNAL]) in addition to clinical history. The donor smoking-PGD association was assessed using logistic regression, and survival analysis was performed using inverse probability of exposure weighting according to smoking category. Measurements and Main Results: Active donor smoking prevalence varied by definition, with 34-43% based on urinary cotinine, 28% by urinary NNAL, and 37% by clinical documentation. The standardized risk of PGD associated with active donor smoking was higher across all definitions, with an absolute risk increase of 11.5% (95% confidence interval [CI], 3.8% to 19.2%) by urinary cotinine, 5.7% (95% CI, -3.4% to 14.9%) by urinary NNAL, and 6.5% (95% CI, -2.8% to 15.8%) defined clinically. Donor smoking was not associated with differential post-lung transplant survival using any definition. Conclusions: Donor smoking associates with a modest increase in PGD risk but not with increased recipient mortality. Use of lungs from smokers is likely safe and may increase lung donor availability. Clinical trial registered with www.clinicaltrials.gov (NCT00552357).

Short-term outcomes after third-time lung transplantation: A single institution experience

BACKGROUND

Reoperative lung transplantation (LTx) survival has improved over time such that a growing number of patients may present for third-time LTx (L3Tx). To understand the safety of L3Tx, we evaluated perioperative outcomes and 3-year survival after L3Tx at a high-volume US LTx center.

METHODS

This retrospective study included all patients who underwent bilateral L3Tx at our institution. Using an optimal matching technique, a primary LTx (L1Tx) cohort was matched 1:2 and a second-time LTx (L2Tx) cohort 1:1. Recipient, operative, and donor characteristics, perioperative outcomes, and 3-year survival were compared among L1Tx, L2Tx, and L3Tx groups.

RESULTS

Eleven L3Tx, 11 L2Tx, and 22 L1Tx recipients were included. Among L3Tx recipients, median age at transplant was 37 years and most (73%) had cystic fibrosis. L3Tx was performed median 6.0 and 10.6 years after L2Tx and L1Tx, respectively. Compared to L1Tx and L2Tx recipients, L3Tx recipients had greater intraoperative transfusion requirements, a higher incidence of postoperative complications, and a higher rate of unplanned reoperation. Rates of grade 3 primary graft dysfunction at 72 hours, extracorporeal membrane oxygenation at 72 hours, reintubation, and in-hospital mortality were similar among groups. There were no differences in 3-year patient (log-rank p = 0.61) or rejection-free survival (log-rank p = 0.34) after L1Tx, L2Tx, and L3Tx.

CONCLUSIONS

At our institution, L3Tx was associated with similar perioperative outcomes and 3-year patient survival compared to L1Tx and L2Tx. L3Tx represents the only safe treatment option for patients with allograft failure after L2Tx; however, further investigation is needed to understand the long-term survival and durability of L3Tx.

Real-world Experiences in the Transplantation of Hepatitis C-NAAT-positive Organs

Background

Hepatitis C virus (HCV) nucleic acid amplification test (NAAT)-positive donors have increased the organ pool. Direct-acting antivirals (DAAs) have led to high rates of treatment success and sustained virologic response (SVR) in recipients with donor-derived HCV infection without significant adverse effects, although variability remains in the timing and duration of antivirals.

Methods

This retrospective study analyzed all adult HCV-NAAT-negative transplant recipients who received an organ from HCV-NAAT-positive donors from November 24, 2018, to March 31, 2022, at Duke University Medical Center with protocolized delay of DAA initiation until after hospital discharge, with at least 180-d follow-up on all patients. Transplant and HCV-related outcomes were analyzed.

Results

Two hundred eleven transplants (111 kidneys, 41 livers, 34 hearts, and 25 lungs) were performed from HCV-NAAT-positive donors to HCV-NAAT-negative recipients. Ninety percent of recipients became viremic within 7 d posttransplant. Ninety-nine percent of recipients were initiated on pangenotypic DAAs in the outpatient setting a median of 52 d posttransplant, most commonly with 12-wk courses of sofosbuvir-velpatasvir (lungs) and glecaprevir-pibrentasvir (heart, kidney, and liver). Ninety-seven percent of recipients had SVR after a first-line DAA; all ultimately achieved SVR at 12 wk after subsequent treatment courses. The median peak HCV RNA for all organ systems was 2 436 512 IU/mL; the median time from antiviral to undetectable RNA was 48 d, although differences were noted between organ groups. No patient deaths or graft losses were directly attributable to HCV infection.

Conclusions

One hundred percent of transplant recipients of HCV-NAAT-positive organs ultimately developed SVR without significant adverse effects when HCV antivirals were initiated in the outpatient setting after transplant hospitalization, suggesting that this real-world treatment pathway is a viable option.

A call to action in thoracic transplant surgical training

Thoracic organ recovery and implantation is increasing in complexity. Simultaneously the logistic burden and associated cost is rising. An electronic survey distributed to the surgical directors of thoracic transplant programs in the United States indicated dissatisfaction amongst 72% of respondents with current procurement training and 85% of respondents favored a process for certification in thoracic organ transplantation. These responses highlight concerns for the current paradigm of training in thoracic transplantation. We discuss the implications of advancements in organ retrieval and implant for surgical training and propose that the thoracic transplant community might address the need through formalized training in procurement and certification in thoracic transplantation.

With Comparable Outcomes, Should Early-Stage Lung Cancer Be a Contraindication to Lung Transplant?

BACKGROUND

Active primary lung malignancy remains a strong contraindication to lung transplantation (LTx). However, outcomes are unclear for patients with early-stage non-small cell lung cancer (NSCLC) who undergo LTx. We hypothesize that patients with early-stage NSCLC incidentally discovered in the explanted lungs have survival comparable to LTx recipients without incidental cancer identified.

METHODS

We performed a single-center retrospective analysis of all LTx recipients from May 2007 to September 2021 with incidental cancer identified in the explanted lungs by pathologist report. Survival statistics were estimated using Kaplan-Meier analysis.

RESULTS

Of the 1586 LTx performed, 23 patients (1.5%) were found to have incidental lung cancer in the explanted lungs. The most common indications for LTx were interstitial lung disease (n = 13) and chronic obstructive pulmonary disease (n = 7), and the most common histologic diagnosis was adenocarcinoma (n = 14). In the cohort with stage I disease (n = 9), the 1- and 5-year unadjusted Kaplan-Meier survival rates were 88.9% and 51.9%, respectively. The 1- and 5-year survival rates for transplant recipients without incidental cancer findings at LTx during this period were 86.7% and 59.4%, respectively, and did not differ significantly between the 2 strata (P = .96).

CONCLUSIONS

Survival rates at 1 and 5 years were comparable between LTx recipients with incidentally noted pathologic stage I NSCLC and contemporary recipients without cancer. All cancer-related deaths occurred in recipients with incidentally noted advanced NSCLC. These results suggest that patients with pathologic stage I lung cancer at the time of transplant have outcomes comparable to those without cancer findings at the time of transplant.

Sterile inflammation in liver transplantation

Sterile inflammation is the immune response to damage-associated molecular patterns (DAMPs) released during cell death in the absence of foreign pathogens. In the setting of solid organ transplantation, ischemia-reperfusion injury results in mitochondria-mediated production of reactive oxygen and nitrogen species that are a major cause of uncontrolled cell death and release of various DAMPs from the graft tissue. When properly regulated, the immune response initiated by DAMP-sensing serves as means of damage control and is necessary for initiation of recovery pathways and re-establishment of homeostasis. In contrast, a dysregulated or overt sterile inflammatory response can inadvertently lead to further injury through recruitment of immune cells, innate immune cell activation, and sensitization of the adaptive immune system. In liver transplantation, sterile inflammation may manifest as early graft dysfunction, acute graft failure, or increased risk of immunosuppression-resistant rejection. Understanding the mechanisms of the development of sterile inflammation in the setting of liver transplantation is crucial for finding reliable biomarkers that predict graft function, and for development of therapeutic approaches to improve long-term transplant outcomes. Here, we discuss the recent advances that have been made to elucidate the early signs of sterile inflammation and extent of damage from it. We also discuss new therapeutics that may be effective in quelling the detrimental effects of sterile inflammation.

Acid exposure time is sensitive for detecting gastroesophageal reflux disease and is associated with long-term survival after lung transplant

Gastroesophageal reflux disease (GERD) is common in patients who have undergone lung transplantation and is associated with poorer outcomes, but guidelines are lacking to direct management strategies in this population. We assessed the diagnostic yield of impedance metrics compared to pH-metry alone for detecting GERD among lung transplant recipients and evaluated their association with clinical outcomes. We performed a retrospective cohort study of consecutive patients who underwent lung transplantation. Demographic data, acid exposure time (AET), number of reflux episodes, mean nocturnal baseline impedance (MNBI), post-reflux swallowing-induced peristaltic wave index (PSPWI), and clinical outcomes including mortality were collected. The relationship between GERD metrics and clinical outcomes was assessed using Wilcoxon signed-rank test and Fisher's exact test as appropriate. Of the 76 patients studied, 29 (38%) had GERD based on abnormal AET after lung transplantation. One (1.3%) patient had GERD based on elevated number of reflux episodes and abnormal distal MNBI detected GERD in 19 (26%) patients, resulting in 62% sensitivity and 94% specificity. Two (2.6%) patients had normal PSPWI. Patients with low distal MNBI had significantly decreased forced expiratory volume in 1 second (FEV1) at 3-year posttransplant compared to those without low distal MNBI (P = 0.03). Three-year survival was significantly worse among patients with elevated AET (66.7% vs. 89.1%, P = 0.03) but not with low distal MNBI (68.4% vs. 84.3%, P = 0.18). Abnormal AET is more sensitive for detecting GERD than other reflux metrics studied and is associated with survival, suggesting pH-metry alone may be sufficient to guide GERD management after lung transplant.

Intraoperative Red Blood Cell Transfusion and Primary Graft Dysfunction After Lung Transplantation

BACKGROUND

In this international, multicenter study of patients undergoing lung transplantation (LT), we explored the association between the amount of intraoperative packed red blood cell (PRBC) transfusion and occurrence of primary graft dysfunction (PGD) and associated outcomes.

METHODS

The Extracorporeal Life Support in LT Registry includes data on LT recipients from 9 high-volume (>40 transplants/y) transplant centers (2 from Europe, 7 from the United States). Adult patients who underwent bilateral orthotopic lung transplant from January 2016 to January 2020 were included. The primary outcome of interest was the occurrence of grade 3 PGD in the first 72 h after LT.

RESULTS

We included 729 patients who underwent bilateral orthotopic lung transplant between January 2016 and November 2020. LT recipient population tertiles based on the amount of intraoperative PRBC transfusion (0, 1-4, and >4 units) were significantly different in terms of diagnosis, age, gender, body mass index, mean pulmonary artery pressure, lung allocation score, hemoglobin, prior chest surgery, preoperative hospitalization, and extracorporeal membrane oxygenation requirement. Inverse probability treatment weighting logistic regression showed that intraoperative PRBC transfusion of >4 units was significantly ( P  < 0.001) associated with grade 3 PGD within 72 h (odds ratio [95% confidence interval], 2.2 [1.6-3.1]). Inverse probability treatment weighting analysis excluding patients with extracorporeal membrane oxygenation support produced similar findings (odds ratio [95% confidence interval], 2.4 [1.7-3.4], P  < 0.001).

CONCLUSIONS

In this multicenter, international registry study of LT patients, intraoperative transfusion of >4 units of PRBCs was associated with an increased risk of grade 3 PGD within 72 h. Efforts to improve post-LT outcomes should include perioperative blood conservation measures.

Adeno-associated virus mediates gene transduction after static cold storage treatment in rodent lung transplantation

OBJECTIVE

Adeno-associated virus is a clinically used gene therapy vector but has not been studied in lung transplantation. We sought to determine the efficacy of adeno-associated virus delivery during static cold storage via the airway versus the pulmonary artery before lung transplantation in a rodent model.

METHODS

Lewis rat lung grafts were treated with a dose of 8e8 or 4e9 viral genome/μL recombinant adeno-associated virus subtype-9 vectors containing firefly luciferase genomes administered via the pulmonary artery or airway during cold storage. A control group did not receive adeno-associated virus. Recipient syngeneic rats then underwent single left lung transplantation. Animals underwent bioluminescence imaging on postoperative days 7, 14, 28, and 56. Explanted tissues were prepared as lysates to quantify luciferase activity. Immunohistochemistry was performed to evaluate cellular transgene expression patterns.

RESULTS

Control animals with no luminescent signal produced a background radiance of 6.1e4 p/s/cm2/sr. In the airway delivery group, mean radiance was greater than the control at 4e9 viral genome/μL postoperative day 7 radiance 6.9e4 p/s/cm2/sr (P = .04). In the pulmonary artery delivery group, we observed greater in vivo luminescence in animals receiving 4e9 viral genome/μL compared with all other groups. However, analysis of tissue lysate revealed greater luminescence in the airway delivery group and suggested off-target expression in heart and liver tissue in the pulmonary artery delivery group. Immunohistochemistry demonstrated transgene staining in distal airway epithelium and alveoli but sparing of the vasculature in the airway delivery group.

CONCLUSIONS

Adeno-associated virus mediates gene transduction during static cold storage in rat lung isografts when administered via the airway and pulmonary artery. Airway administration leads to robust transgene expression in respiratory epithelial cells, whereas pulmonary artery administration targets alternative cell types and increases extrapulmonary transgene expression.

Pulmonary Open, Robotic, and Thoracoscopic Lobectomy (PORTaL) Study: Survival Analysis of 6646 Cases

OBJECTIVE

The aim of this study was to analyze overall survival (OS) of robotic-assisted lobectomy (RL), video-assisted thoracoscopic lobectomy (VATS), and open lobectomy (OL) performed by experienced thoracic surgeons across multiple institutions.

SUMMARY BACKGROUND DATA

Surgeons have increasingly adopted RL for resection of early-stage lung cancer. Comparative survival data following these approaches is largely from single-institution case series or administrative data sets.

METHODS

Retrospective data was collected from 21 institutions from 2013 to 2019. Consecutive cases performed for clinical stage IA-IIIA lung cancer were included. Induction therapy patients were excluded. The propensity-score method of inverse-probability of treatment weighting was used to balance baseline characteristics. OS was estimated using the Kaplan-Meier method. Multivariable Cox proportional hazard models were used to evaluate association among OS and relevant risk factors.

RESULTS

A total of 2789 RL, 2661 VATS, and 1196 OL cases were included. The unadjusted 5-year OS rate was highest for OL (84%) followed by RL (81%) and VATS (74%); P =0.008. Similar trends were also observed after inverse-probability of treatment weighting adjustment (RL 81%; VATS 73%, OL 85%, P =0.001). Multivariable Cox regression analyses revealed that OL and RL were associated with significantly higher OS compared with VATS (OL vs. VATS: hazard ratio=0.64, P <0.001 and RL vs. VATS: hazard ratio=0.79; P =0.007).

CONCLUSIONS

Our finding from this large multicenter study suggests that patients undergoing RL and OL have statistically similar OS, while the VATS group was associated with shorter OS. Further studies with longer follow-up are necessary to help evaluate these observations.

Robotic Esophagectomy Trends and Early Surgical Outcomes: The US Experience

BACKGROUND

Recent esophagectomy trends were evaluated to describe the shift in surgical approach and outcomes using The Society of Thoracic Surgeons General Thoracic Surgery Database.

METHODS

All patients who underwent an esophagectomy with gastric conduit from 2015 to 2019 were identified and analyzed according to original intended approach. After performing volume trend analysis of patients, operative outcomes were evaluated.

RESULTS

Among 10,607 patients, esophagectomy was open in 5763 (54.3%), minimally invasive (MIE) in 3524 (33.2%), and robotic (RAMIE) in 1320 (12.4%). Within 5 years, MIE and RAMIE combined rose to majority approach (open from 58% to 42% of annual volume). While MIE and RAMIE were associated with higher rates of anastomotic leak, loss of conduit, pulmonary embolus, and reoperation, R0 resection and harvested number of lymph nodes exceeded those in open approaches. Operative mortality did not differ by approach (3.21% open vs 2.72% MIE vs 2.50% RAMIE; P = .2329). On multivariable analysis, RAMIE was independently associated with higher rate of anastomotic leak compared to open (adjusted odds ratio 1.53, 95% CI 1.14-2.04), while both MIE and RAMIE had lower mean length of stay. Propensity matching of 1320 pairs found a higher risk of anastomotic leak requiring surgery for RAMIE compared with MIE (adjusted odds ratio 1.39, 95% CI 1.01-1.92).

CONCLUSIONS

In less than a decade, the dominant surgical approach in The Society of Thoracic Surgeons General Thoracic Surgery Database has become minimally invasive (RAMIE and MIE). While anastomotic leak and reoperation, more common in RAMIE, require a technical solution, these complications have not raised operative mortality. Further studies are needed to address long-term results and oncologic outcome.

Addressing sex-based disparities in solid organ transplantation in the United States - a conference report

Solid organ transplantation provides the best treatment for end-stage organ failure, but significant sex-based disparities in transplant access exist. On June 25, 2021, a virtual multidisciplinary conference was convened to address sex-based disparities in transplantation. Common themes contributing to sex-based disparities were noted across kidney, liver, heart, and lung transplantation, specifically the existence of barriers to referral and wait listing for women, the pitfalls of using serum creatinine, the issue of donor/recipient size mismatch, approaches to frailty and a higher prevalence of allosensitization among women. In addition, actionable solutions to improve access to transplantation were identified, including alterations to the current allocation system, surgical interventions on donor organs, and the incorporation of objective frailty metrics into the evaluation process. Key knowledge gaps and high-priority areas for future investigation were also discussed.

Same-teams versus different-teams for long distance lung procurement: A cost analysis

OBJECTIVE

In an era of broader lung sharing, different-team transplantation (DT, procuring team from nonrecipient center) may streamline procurement logistics; however, safety and cost implications of DT remain unclear. To understand whether DT represents a safe means to reduce lung transplant (LTx) costs, we compared posttransplant outcomes and lung procurement and index hospitalization costs among matched DT and same-team transplantation (ST, procuring team from recipient center) cohorts at a single, high-volume institution. We hypothesized that DT reduces costs without compromising outcomes after LTx.

METHODS

Patients who underwent DT between January 2016 to May 2020 were included. A cohort of patients who underwent ST was matched 1:3 (nearest neighbor) based on recipient age, disease group, lung allocation score, history of previous LTx, and bilateral versus single LTx. Posttransplant outcomes and costs were compared between groups.

RESULTS

In total, 23 DT and 69 matched ST recipients were included. Perioperative outcomes and posttransplant survival were similar between groups. Compared with ST, DT was associated with similar lung procurement and index hospitalization costs (DT vs ST, procurement: median $65,991 vs $58,847, P = .16; index hospitalization: median $294,346 vs $322,189, P = .7). On average, procurement costs increased $3263 less per 100 nautical miles for DT versus ST; DT offered cost-savings when travel distances exceeded approximately 363 nautical miles.

CONCLUSIONS

At our institution, DT and ST were associated with similar post-LTx outcomes; DT offered cost-savings with increasing procurement travel distance. These findings suggest that DT may mitigate logistical and financial burdens of lung procurement; however, further investigation in a multi-institutional cohort is warranted.

Early posttransplant reductions in club cell secretory protein associate with future risk for chronic allograft dysfunction in lung recipients: results from a multicenter study

BACKGROUND

Chronic lung allograft dysfunction (CLAD) increases morbidity and mortality for lung transplant recipients. Club cell secretory protein (CCSP), produced by airway club cells, is reduced in the bronchoalveolar lavage fluid (BALF) of lung recipients with CLAD. We sought to understand the relationship between BALF CCSP and early posttransplant allograft injury and determine if early posttransplant BALF CCSP reductions indicate later CLAD risk.

METHODS

We quantified CCSP and total protein in 1606 BALF samples collected over the first posttransplant year from 392 adult lung recipients at 5 centers. Generalized estimating equation models were used to examine the correlation of allograft histology or infection events with protein-normalized BALF CCSP. We performed multivariable Cox regression to determine the association between a time-dependent binary indicator of normalized BALF CCSP level below the median in the first posttransplant year and development of probable CLAD.

RESULTS

Normalized BALF CCSP concentrations were 19% to 48% lower among samples corresponding to histological allograft injury as compared with healthy samples. Patients who experienced any occurrence of a normalized BALF CCSP level below the median over the first posttransplant year had a significant increase in probable CLAD risk independent of other factors previously linked to CLAD (adjusted hazard ratio 1.95; p = 0.035).

CONCLUSIONS

We discovered a threshold for reduced BALF CCSP to discriminate future CLAD risk; supporting the utility of BALF CCSP as a tool for early posttransplant risk stratification. Additionally, our finding that low CCSP associates with future CLAD underscores a role for club cell injury in CLAD pathobiology.

Utilization Trends and Volume-outcomes Relationship of Endoscopic Resection for Early Stage Esophageal Cancer

OBJECTIVES

We describe utilization trends and center volume-outcomes relationship of ER of early stage esophageal cancer using a large hospitalbased registry.

SUMMARY OF BACKGROUND DATA

ER is increasingly accepted as the preferred treatment for early stage esophageal cancer, however its utilization and the center volume-outcomes relationship in the United States is unknown.

METHODS

The National Cancer Database was used to identify patients with cT1N0M0 esophageal cancer treated with ER or esophagectomy between 2004 and 2015. Relative frequencies were plotted over time. Restricted cubic splines and maximally selected rank statistics were used to identify an inflection point of center volume and survival.

RESULTS

A total of 1136 patients underwent ER and 2829 patients underwent esophagectomy during the study period. Overall utilization of ER, and relative use compared to esophagectomy, increased throughout the study period. Median annualized center ER volume was 1.9 cases per year (interquartile range 0.5-5.8). Multivariable Cox regression showed increasing annualized center volume by 1 case per year was associated with improved survival. Postoperative 30- or 90-day mortality, 30-day readmission, and pathologic T upstaging rates were similar irrespective of center volume.

CONCLUSIONS

Utilization of ER compared to esophagectomy for stage I esophageal cancer has increased over the past decade, though many individual centers perform fewer than 1 case annually. increasing annualized center volume by one procedure per year was associated with improved survival. increased volume beyond this was not associated with survival benefit. Referral to higher volume centers for treatment of superficial esophageal cancer should be considered.

Pulmonary Open, Robotic, and Thoracoscopic Lobectomy study: Outcomes and risk factors of conversion during minimally invasive lobectomy

OBJECTIVE

Conversion to thoracotomy continues to be a concern during minimally invasive lobectomy. The aim of this propensity-matched cohort study is to analyze the outcomes and risk factors of intraoperative conversion during video-assisted thoracoscopic surgery (VATS) and robotic lobectomy (RL).

METHODS

Data from consecutive lobectomy cases performed for clinical stage IA to IIIA lung cancer was retrospectively collected from the Pulmonary Open, Robotic, and Thoracoscopic Lobectomy study consortium of 21 institutions from 2011 to 2019. The propensity-score method of inverse-probability of treatment weighting was used to balance the baseline characteristics across surgical approaches. Univariate logistic regression models were applied to test risk factors for conversion. Multivariable logistic regression analysis was conducted using a stepwise model selection method.

RESULTS

Seven thousand two hundred sixteen patients undergoing lobectomy were identified: RL (n = 2968), VATS (n = 2831), and open lobectomy (n = 1417). RL had lower conversion rate compared with VATS (3.6% vs 12.9%; P < .0001). In the multivariable regression model, tumor size and neoadjuvant therapy were the most significant risk factors for conversion, followed by prior cardiac surgery, congestive heart failure, chronic obstructive pulmonary disease, VATS approach, male gender, body mass index, and forced expiratory volume in 1 minute. Conversions for anatomical reasons were more common in VATS than RL (66.6% vs 45.6%; P = .0002); however, conversions for vascular reasons were more common in RL than VATS (24.8% vs 14%; P = .01). The rate of emergency conversions was comparable between RL and VATS (0.5% vs 0.7%; P = .25) with no intraoperative mortalities.

CONCLUSIONS

Converted minimally invasive lobectomies were not associated with worse perioperative mortality compared with open lobectomy. Compared with VATS lobectomy, RL is associated with a lower probability of conversion in this propensity-score matched cohort study.

Textbook outcome in lung transplantation: Planned venoarterial extracorporeal membrane oxygenation versus off-pump support for patients without pulmonary hypertension

BACKGROUND

Planned venoarterial extracorporeal membrane oxygenation (VA ECMO) is increasingly used during bilateral orthotopic lung transplantation (BOLT) and may be superior to off-pump support for patients without pulmonary hypertension. In this single-institution study, we compared rates of textbook outcome between BOLTs performed with planned VA ECMO or off-pump support for recipients with no or mild pulmonary hypertension.

METHODS

Patients with no or mild pulmonary hypertension who underwent isolated BOLT between 1/2017 and 2/2021 with planned off-pump or VA ECMO support were included. Textbook outcome was defined as freedom from intraoperative complication, 30-day reintervention, 30-day readmission, post-transplant length of stay >30 days, 90-day mortality, 30-day acute rejection, grade 3 primary graft dysfunction at 48 or 72 hours, post-transplant ECMO, tracheostomy within 7 days, inpatient dialysis, reintubation, and extubation >48 hours post-transplant. Textbook outcome achievement was compared between groups using multivariable logistic regression.

RESULTS

Two hundred thirty-seven BOLTs were included: 68 planned VA ECMO and 169 planned off-pump. 14 (20.6%) planned VA ECMO and 27 (16.0%) planned off-pump patients achieved textbook outcome. After adjustment for prior BOLT, lung allocation score, ischemic time, and intraoperative transfusions, planned VA ECMO was associated with higher odds of textbook outcome than planned off-pump support (odds ratio 3.89, 95% confidence interval 1.58-9.90, p = 0.004).

CONCLUSIONS

At our institution, planned VA ECMO for isolated BOLT was associated with higher odds of textbook outcome than planned off-pump support among patients without pulmonary hypertension. Further investigation in a multi-institutional cohort is warranted to better elucidate the utility of this strategy.

Complement-targeting therapeutics for ischemia-reperfusion injury in transplantation and the potential for ex vivo delivery

Organ shortages and an expanding waitlist have led to increased utilization of marginal organs. All donor organs are subject to varying degrees of IRI during the transplant process. Extended criteria organs, including those from older donors and organs donated after circulatory death are especially vulnerable to ischemia-reperfusion injury (IRI). Involvement of the complement cascade in mediating IRI has been studied extensively. Complement plays a vital role in the propagation of IRI and subsequent recruitment of the adaptive immune elements. Complement inhibition at various points of the pathway has been shown to mitigate IRI and minimize future immune-mediated injury in preclinical models. The recent introduction of ex vivo machine perfusion platforms provides an ideal window for therapeutic interventions. Here we review the role of complement in IRI by organ system and highlight potential therapeutic targets for intervention during ex vivo machine preservation of donor organs.

Gene Therapy: Will the Promise of Optimizing Lung Allografts Become Reality?

Lung transplantation is the definitive therapy for patients living with end-stage lung disease. Despite significant progress made in the field, graft survival remains the lowest of all solid organ transplants. Additionally, the lung has among the lowest of organ utilization rates-among eligible donors, only 22% of lungs from multi-organ donors were transplanted in 2019. Novel strategies are needed to rehabilitate marginal organs and improve graft survival. Gene therapy is one promising strategy in optimizing donor allografts. Over-expression or inhibition of specific genes can be achieved to target various pathways of graft injury, including ischemic-reperfusion injuries, humoral or cellular rejection, and chronic lung allograft dysfunction. Experiments in animal models have historically utilized adenovirus-based vectors and the majority of literature in lung transplantation has focused on overexpression of IL-10. Although several strategies were shown to prevent rejection and prolong graft survival in preclinical models, none have led to clinical translation. The past decade has seen a renaissance in the field of gene therapy and two AAV-based in vivo gene therapies are now FDA-approved for clinical use. Concurrently, normothermic ex vivo machine perfusion technology has emerged as an alternative to traditional static cold storage. This preservation method keeps organs physiologically active during storage and thus potentially offers a platform for gene therapy. This review will explore the advantages and disadvantages of various gene therapy modalities, review various candidate genes implicated in various stages of allograft injury and summarize the recent efforts in optimizing donor lungs using gene therapy.

Risk of Each of the Five Lung Lobectomies: A Society of Thoracic Surgery Database Analysis

BACKGROUND

The perioperative risk of pulmonary lobectomy as a solitary procedure has been extensively studied, yet the differences in outcomes between each lobe, which have unique anatomy and a different amount of lung parenchyma, are entirely unknown. The purpose of this study is to define the risk of each of the five lobectomies.

METHODS

The Society of Thoracic Surgery Database was queried for patients undergoing lobectomy between 2008 and 2018. Patient and disease characteristics, operative variables, major morbidity and 30-day mortality were examined. A multivariable logistic regression model (using the same variables in the current STS lobectomy risk model) was developed to assess for the contribution to lobectomy site to adverse outcomes.

RESULTS

65,006 patients were analyzed. Adjusted perioperative mortality rate is lowest for RML (0.63%) intermediate for RUL, LUL and LLL (1.08-1.24%), and highest for RLL (1.63%). The adjusted major morbidity rate is lowest for RML (5.36%) intermediate for LLL and LUL (7.82-8.33%), and highest for RUL and RLL (8.94-9.32%). Adjusted intraoperative transfusion rate is lowest for RML (1.37%) intermediate for RLL and LLL (1.81-1.94%) and highest for RUL and LUL (2.47-2.72%).

CONCLUSIONS

There are clear differences in postoperative outcomes by lobectomy location. Mortality, major morbidity, and transfusion rate are lowest for RML, but vary across other lobectomies. These differences should be appreciated when evaluating risk of operation, deciding upon best therapy, counseling patients, and comparing outcomes.

Two Compartment Evaluation of Liver Grafts During Acellular Room Temperature Machine Perfusion (acRTMP) in a Rat Liver Transplant Model

Background

Subnormothermic machine perfusion (SNMP) of liver grafts is currently less clinically developed than normothermic and hypothermic approaches, but may have logistical advantages. At intermediate temperatures, the oxygen demand of the graft is low enough to be satisfied with an acellular perfusate, obviating the need for oxygen carrying molecules. This intermediate metabolic rate, however, is sufficient to support the production of bile, which is emerging as an important indicator of graft injury and viability. In this study, we hypothesized that the biliary compartment would be more sensitive than perfusate in detecting graft injury during SNMP.

Methods

To test this hypothesis in a rat model, we performed liver transplants with DCD and control liver grafts after 1 h of acellular room temperature machine perfusion (acRTMP) or static cold storage (SCS). Point of care liver function tests were measured in biliary and perfusate samples after 1 h of machine perfusion. Following transplantation, rats were sacrificed at 24 h for assessment of post-transplant graft function and histology.

Results

All point-of-care liver function tests were significantly more concentrated in the biliary compartment than the perfusate compartment during acRTMP. DCD liver grafts could be distinguished from control liver grafts by significantly higher markers of hepatocyte injury (AST, ALT) in the biliary compartment, but not in the perfusate compartment. Classical markers of cholangiocyte injury, such as gammy-glut amyl transferase (GGT), amylase (AML), and alkaline phosphatase were detectable in the biliary compartment, but not in the perfusate compartment. In comparison to SCS, graft preservation by acRTMP produced a significant survival benefit in DCD liver transplantation (75 vs. 0%, p < 0.0030).

Conclusion

Together, these findings demonstrate that during acRTMP, the biliary compartment may be a more sensitive indicator of graft injury than the perfusate compartment. Moreover, acRTMP provides superior graft preservation to SCS in rat DCD liver transplantation.

Factors associated with short- versus long-term survival after lung transplant

OBJECTIVE

A small but growing proportion of lung transplant recipients survive longer than a decade post-transplant. The aim of this study was to identify factors associated with survival beyond a decade after lung transplant.

METHODS

We queried the United Network for Organ Sharing registry for adult (age ≥18 years) recipients undergoing first-time isolated lung transplantation between the introduction of the Lung Allocation Score in 2005 and 2009. Recipients were stratified into 3 cohorts: those who survived less than 1 year, 1 to 10 years, and greater than 10 years. Multivariable logistic regression was used to identify factors independently associated with early mortality (<1 year) and long-term (>10 years) survival.

RESULTS

A total of 5171 lung transplant recipients and their associated donors met inclusion criteria, including 964 (18.6%) with early mortality, 2843 (55.0%) with intermediate survival, and 1364 (26.3%) long-term survivors. Factors independently associated with early mortality included donor Black race, cigarette use, arterial oxygen partial pressure/fractional inspired oxygen ratio, diabetes, recipient Lung Allocation Score, total bilirubin, extracorporeal membrane oxygenation bridge requirement, single lung transplantation, and annual lung transplant center volume. The only factors independently associated with long-term survival among those who survived at least 1 year was donor age and single lung transplantation.

CONCLUSIONS

Of patients undergoing lung transplantation after the implementation of the Lung Allocation Score, approximately one-quarter survived 10 years post-transplant. There was minimal overlap between the factors associated with 1-year and 10-year survival. Of note, the Lung Allocation Score was not associated with long-term survival. Further research is needed to better refine patient selection and optimize management strategies to increase the number of long-term survivors.

Lung transplantation after ex vivo lung perfusion versus static cold storage: An institutional cost analysis

Ex vivo lung perfusion (EVLP) is a novel lung preservation strategy that facilitates the use of marginal allografts; however, it is more expensive than static cold storage (SCS). To understand how preservation method might affect postoperative costs, we compared outcomes and index hospitalization costs among matched EVLP and SCS preserved lung transplant (LTx) recipients at a single, high-volume institution. A total of 22 EVLP and 66 matched SCS LTx recipients were included; SCS grafts were further stratified as either standard-criteria (SCD) or extended-criteria donors (ECD). Median total preservation time was 857, 409, and 438 min for EVLP, SCD, and ECD lungs, respectively (p < .0001). EVLP patients had similar perioperative outcomes and posttransplant survival compared to SCS SCD and ECD recipients. Excluding device-specific costs, total direct variable costs were similar among EVLP, SCD, and ECD recipients (median $200,404, vs. $154,709 vs. $168,334, p =  .11). The median direct contribution margin was positive for EVLP recipients, and similar to that for SCD and ECD graft recipients (all p > .99). These findings demonstrate that the use of EVLP was profitable at an institutional level; however, further investigation is needed to better understand the financial implications of EVLP in facilitating donor pool expansion in an era of broader lung sharing.

Textbook surgical outcome in lung transplantation: Analysis of a US national registry

Textbook surgical outcome (TO) is a novel composite quality measure in lung transplantation (LTx). Compared to one-year survival metrics, TO may better differentiate center performance, and motivate improvements in care. To understand the feasibility of implementing this metric, we defined TO in LTx using US national data, and evaluated its ability to predict post-transplant outcomes and differentiate center performance. Adult patients who underwent isolated LTx between 2016-2019 were included. TO was defined as freedom from post-transplant length of stay >30 days, 90-day mortality, intubation or extracorporeal membrane oxygenation at 72 hours post-transplant, post-transplant ventilator support lasting ≥5 days, postoperative airway dehiscence, inpatient dialysis, pre-discharge acute rejection, and grade 3 primary graft dysfunction at 72 hours. Recipient and donor characteristics and post-transplant outcomes were compared between patients who achieved and failed TO. Of 8959 lung transplant recipients, 4664 (52.1%) achieved TO. Patient and graft survival were improved among patients who achieved TO (both log-rank p<0.0001). Among 62 centers, adjusted rates of TO ranged from 27.0% to 72.4% reflecting a wide variability in center-level performance. TO defined using national data may represent a novel composite metric to guide quality improvement in LTx across US transplant centers. Summary: In this study we defined textbook outcome (TO) for lung transplantation (LTx) using US national data. We found that achievement of TO was associated with improved post-transplant survival, and wide variability in center-level LTx performance. These findings suggest that TO could be readily implemented to compare quality of care among US LTx centers. This article is protected by copyright. All rights reserved.

Conversion to Thoracotomy During Thoracoscopic versus Robotic Lobectomy: Predictors and Outcomes

BACKGROUND

Conversion to thoracotomy during minimally invasive lobectomy for lung cancer is occasionally necessary. Differences between video-assisted thoracoscopic (VATS) and robotic-assisted (RATS) lobectomy conversion have not been described.

METHODS

We queried The Society of Thoracic Surgeons (STS) General Thoracic Surgery Database (GTSD) from January 1, 2015 to December 31, 2018. Patients with prior thoracic operations and metastatic disease were excluded. Univariable comparisons with Chi-squared and Kruskal-Wallis tests and multivariable logistic regression modeling were performed.

RESULTS

There were 27,695 minimally invasive lobectomies from 269 centers. Conversion to thoracotomy occurred in 11.0% of VATS and 6.0% of RATS (p<0.001). Conversion was associated with increased mortality (p<0.001), major complications (p<0.001), and intra- (p<0.001) and post-operative (p<0.001) blood transfusions. Conversion from RATS occurred emergently (p<0.001) and for vascular injury (p<0.001) more frequently than from VATS, but there was no difference in overall major complications or mortality. Mortality following conversion was 3.1% for RATS and 2.2% for VATS (p=0.24). Clinical cancer stage II or III (p<0.001), preoperative chemotherapy (p=0.003), FEV1 (p=0.006), BMI (p<0.001), and left-sided resection (p=0.0002) independently predicted VATS conversion. For RATS, clinical stage III (p=0.037), left-sided resection (0.041), and FEV1 (p=0.002) predicted conversion. Lower volume centers had increased rates of conversion (p<0.001) in both groups.

CONCLUSIONS

Conversion from minimally invasive to open lobectomy is associated with increased morbidity and mortality. Conversion occurs more frequently during VATS compared to RATS, although less often emergently, and with similar rates of overall mortality and major complication. Predictors, urgency, and reasons for conversion differ between RATS and VATS lobectomy and may assist in patient selection.

Inhaled Pulmonary Vasodilator Therapy in Adult Lung Transplant: A Randomized Clinical Trial

Importance

Inhaled nitric oxide (iNO) is commonly administered for selectively inhaled pulmonary vasodilation and prevention of oxidative injury after lung transplant (LT). Inhaled epoprostenol (iEPO) has been introduced worldwide as a cost-saving alternative to iNO without high-grade evidence for this indication.

Objective

To investigate whether the use of iEPO will lead to similar rates of severe/grade 3 primary graft dysfunction (PGD-3) after adult LT when compared with use of iNO.

Design, Setting, and Participants

This health system-funded, randomized, blinded (to participants, clinicians, data managers, and the statistician), parallel-designed, equivalence clinical trial included 201 adult patients who underwent single or bilateral LT between May 30, 2017, and March 21, 2020. Patients were grouped into 5 strata according to key prognostic clinical features and randomized per stratum to receive either iNO or iEPO at the time of LT via 1:1 treatment allocation.

Interventions

Treatment with iNO or iEPO initiated in the operating room before lung allograft reperfusion and administered continously until cessation criteria met in the intensive care unit (ICU).

Main Outcomes and Measures

The primary outcome was PGD-3 development at 24, 48, or 72 hours after LT. The primary analysis was for equivalence using a two one-sided test (TOST) procedure (90% CI) with a margin of 19% for between-group PGD-3 risk difference. Secondary outcomes included duration of mechanical ventilation, hospital and ICU lengths of stay, incidence and severity of acute kidney injury, postoperative tracheostomy placement, and in-hospital, 30-day, and 90-day mortality rates. An intention-to-treat analysis was performed for the primary and secondary outcomes, supplemented by per-protocol analysis for the primary outcome.

Results

A total of 201 randomized patients met eligibility criteria at the time of LT (129 men [64.2%]). In the intention-to-treat population, 103 patients received iEPO and 98 received iNO. The primary outcome occurred in 46 of 103 patients (44.7%) in the iEPO group and 39 of 98 (39.8%) in the iNO group, leading to a risk difference of 4.9% (TOST 90% CI, -6.4% to 16.2%; P = .02 for equivalence). There were no significant between-group differences for secondary outcomes.

Conclusions and Relevance

Among patients undergoing LT, use of iEPO was associated with similar risks for PGD-3 development and other postoperative outcomes compared with the use of iNO.

Trial Registration

ClinicalTrials.gov identifier: NCT03081052.

Lung retransplantation in the modern era

Chronic lung allograft dysfunction remains the leading cause of long-term morbidity and mortality for lung transplant recipients. Lung retransplantation currently represents the only therapeutic option for patients for refractory allograft dysfunction. However, debate remains regarding both the efficacy and ethicality of lung retransplantation in light of the shortage of lung allografts. The aim of this review is to discuss the available literature on lung retransplantation in the current era. Through this we hope to provide insight into ideal patient selection, donor organ selection, surgical approaches, and future considerations within the field in order to improve outcomes and best address organ utilization while a waitlist continues to exist. Lung retransplantation in select patients can offer comparable survival outcomes to primary lung transplantation. However, several risk factors including retransplantation with the first year of primary transplantation, older age, poor functional status, and ICU level requirements prior to transplantation are associated with worsened outcomes. Donor organ selection considerations are comparable to those in primary lung transplantation. However, surgical approach is often impacted by dense pleural and mediastinal adhesions in the recipient which increase the complexity of the hilar dissection. The postoperative course is often more complex for patients undergoing retransplantation compared to those undergoing primary lung transplant as well. However, pending more data on long term outcomes in lung retransplantation and the potential impact of retransplant recipients on waitlist mortality, lung retransplantation should remain in use primarily for the treatment of chronic graft dysfunction in carefully selected patients.

Lung transplantation using allografts with more than 8 hours of ischemic time: A single-institution experience

BACKGROUND

Six hours was historically regarded as the limit of acceptable ischemic time for lung allografts. However, broader sharing of donor lungs often necessitates use of allografts with ischemic time >6 hours. We characterized the association between ischemic time ≥8 hours and outcomes after lung transplantation using a contemporary cohort from a high-volume institution.

METHODS

Patients who underwent primary isolated bilateral lung transplantation between 1/2016 and 5/2020 were included. Patients bridged to transplant with extracorporeal membrane oxygenation or mechanical ventilation, and ex-vivo perfusion cases were excluded. Recipients were stratified by total allograft ischemic time <8 hours (standard) vs ≥8 hours (long). Perioperative outcomes and post-transplant survival were compared between groups.

RESULTS

Of 358 patients, 95 (26.5%) received long ischemic time (≥8 hours) lungs. Long ischemic time recipients were more likely to be male and have donation after circulatory death donors than standard ischemic time recipients. On unadjusted analysis, long and standard ischemic time recipients had similar survival, and similar rates of grade 3 primary graft dysfunction at 72 hours, extracorporeal membrane oxygenation post-transplant, acute rejection within 30 days, reintubation, and post-transplant length of stay. After adjustment, long and standard ischemic time recipients had comparable risks of mortality or graft failure.

CONCLUSIONS

In a modern cohort, use of lung allografts with "long" ischemic time ≥8 hours were associated with acceptable perioperative outcomes and post-transplant survival. Further investigation is required to better understand how broader use impacts post-lung transplant outcomes and the implications for smarter sharing under an evolving national allocation policy.