Limited Effect of Prevention Strategies on Incidence of Clinically Detectable Venous Thromboembolism After Lung Transplantation.

BACKGROUND: Thromboembolic complications are common post-lung transplant, leading to significant morbidity. We instituted multiple interventions because of an observed 36.8% incidence of venous thromboembolism (VTE) (Incidence rate (IR) 5.74/1000 pt days) in our recipients. METHODS: Our initiative commenced January 2015 with enoxaparin initiation within 6-8 hours of intensive care unit arrival and continuation for 4-6 weeks. We evaluated the IR of VTE in lung transplant recipients within 90 days of transplant. In 2017, the protocol was modified to extend the time to initiation of prophylaxis to within 72 hours of ICU arrival. In 2019, we further amended our intraoperative vascular access strategy. RESULTS: Eighteen of 26 lung transplant recipients (LTR) met inclusion criteria in the 2015 cohort. Six of 18 (33.3%) developed VTE, 50% of which were upper extremity (UE), line associated. Fifty two of 75 LTR were eligible for enoxaparin prophylaxis in the 2017 cohort. Fifteen of 52 subjects (28.8%) developed VTE, 77.8% of which were UE and line associated. Despite improved adherence in 2017, there was little change in VTE IR (3.90/1000 pt days compared with 3.85/1000 pt days). Twenty six of 43 LTR met protocol inclusion criteria in the 2019 cohort. Ten subjects (38.5%) developed VTE, 67% of which were UE and line associated (IR 5.18/1000 pt days). CONCLUSION: Our prospective study found that LTR remain at high risk for VTE despite aggressive prophylaxis with 4-6 weeks of enoxaparin and adjustment of vascular access approach. Alternative interventions should be investigated to minimize VTE development in this vulnerable population.

Adverse Outcomes Associated With Atrial Arrhythmias After Veno-Venous Extracorporeal Membrane Oxygenation.

Veno-venous extracorporeal membrane oxygenation (VV ECMO) is used as a treatment modality in those who fail to respond to conventional care. Hypoxia and medications used in the intensive care unit may increase risk for atrial arrhythmias (AA). This study aims to evaluate the impact of AA on post-VV ECMO outcome. A retrospective review of patients who were placed on VV ECMO between October 2016 and October 2021. One hundred forty-five patients were divided into two groups, AA and no AA. Baseline characteristic and potential risk factors were assessed. Uni- and multivariate analysis using logistic regression models were constructed to evaluate the predictors of mortality between groups. Survival between groups was estimated by the Kaplan-Meier method using the log-rank test. Advanced age with history of coronary artery disease and hypertension were associated with increased risk to develop AA post-VV ECMO placement ( p value < 0.05). Length on ECMO, time intubated, hospital length of stay, and sepsis were significantly increased in patients in the AA group ( p value < 0.05). There was no difference in the overall mortality between the two groups. AAs were associated with worse hospital course and complications but no difference in overall mortality rate. Age and cardiovascular disease seem to be predisposing risk factors for this. Further studies are needed to investigate potential strategies to prevent AAs development in this population.

IL-33 mediates Pseudomonas induced airway fibrogenesis and is associated with CLAD.

BACKGROUND: Long term outcomes of lung transplantation are impacted by the occurrence of chronic lung allograft dysfunction (CLAD). Recent evidence suggests a role for the lung microbiome in the occurrence of CLAD, but the exact mechanisms are not well defined. We hypothesize that the lung microbiome inhibits epithelial autophagic clearance of pro-fibrotic proteins in an IL-33 dependent manner, thereby augmenting fibrogenesis and risk for CLAD. METHODS: Autopsy derived CLAD and non-CLAD lungs were collected. IL-33, P62 and LC3 immunofluorescence was performed and assessed using confocal microscopy. Pseudomonas aeruginosa (PsA), Streptococcus Pneumoniae (SP), Prevotella Melaninogenica (PM), recombinant IL-33 or PsA-lipopolysaccharide was co-cultured with primary human bronchial epithelial cells (PBEC) and lung fibroblasts in the presence or absence of IL-33 blockade. Western blot analysis and quantitative reverse transcription (qRT) PCR was performed to evaluate IL-33 expression, autophagy, cytokines and fibroblast differentiation markers. These experiments were repeated after siRNA silencing and upregulation (plasmid vector) of Beclin-1. RESULTS: Human CLAD lungs demonstrated markedly increased expression of IL-33 and reduced basal autophagy compared to non-CLAD lungs. Exposure of co-cultured PBECs to PsA, SP induced IL-33, and inhibited PBEC autophagy, while PM elicited no significant response. Further, PsA exposure increased myofibroblast differentiation and collagen formation. IL-33 blockade in these co-cultures recovered Beclin-1, cellular autophagy and attenuated myofibroblast activation in a Beclin-1 dependent manner. CONCLUSION: CLAD is associated with increased airway IL-33 expression and reduced basal autophagy. PsA induces a fibrogenic response by inhibiting airway epithelial autophagy in an IL-33 dependent manner.

Image-guided video-assisted thoracoscopic surgery (iVATS): a single center experience and review.

Lung cancer screening techniques using low-dose computed tomography (LDCT) scans have improved over the last decade. This means that there is an increased rate of detection of small, often non-palpable, nodules and ground-glass opacities. Obtaining a definitive diagnosis of these nodules using techniques such as percutaneous image-guided biopsy or intraoperative localization is challenging, and these nodules have traditionally undergone routine surveillance. Image-guided video-assisted thoracoscopic surgery (iVATS), which is performed in a hybrid operating room, has made it more feasible to biopsy and resect these nodules. The first thoracic surgery hybrid operative room was introduced at our institution at Brigham and Women's Hospital. Herein, we describe our experience implementing this technique including the methods we used to train key personnel such as radiologists, surgeons, and anesthesiologists to ensure that this technique successfully translated to a clinical setting. We review the benefits of iVATS, which includes decreased rate of fiducial dislodgement, real-time imaging which facilitates successful fiducial placement, and smaller sized resection of lung parenchyma. We will also describe the comparisons between traditional diagnostic methods and iVATS, patient selection criteria and important technical details. Some centers describe alternative techniques for several of the technical aspects, including patient positioning, which we also mention. Lastly, we describe adverse events after iVATS, which are comparable to those seen after a standard VATS.

1-year outcomes for lung transplantation recipients with non-alcoholic fatty liver disease.

Advanced hepatic fibrosis and cirrhosis are absolute contraindications to lung transplantation. [ 1] However, whether fatty liver disease with mild-moderate fibrosis contributes to increased adverse outcomes post-lung transplantation remains unknown. We present a retrospective analysis of patients transplanted at Brigham and Women's Hospital between 2015 and 2017 to identify whether patients with mild-moderate non-alcoholic fatty liver disease (NAFLD) experience increased short-term complications compared to patients with normal liver architecture. Patients with advanced (F3-F4) fibrosis and/or cirrhosis were considered non-suitable transplant candidates, a priori. This study was powered for a difference in index hospital-free days within the first 30 days of 25% (α=0.05, ß=0.8). Secondary outcomes included index intensive care unit (ICU)-free days within the first 10 days post-transplant, perioperative blood product transfusion, incidence of index hospitalisation arrhythmias and delirium, need for insulin on discharge post-transplant, tacrolimus dose required to maintain a trough of 8-12 ng·mL-1 at index hospital discharge, and 1-year post-transplant incidence of insulin-dependent diabetes, acute kidney injury, acute cellular rejection, unplanned hospital readmissions and infection. 150 patients underwent lung transplantation between 2015 and 2017 and were included in the analysis; of these patients 40 (27%) had evidence of NAFLD. Median index hospital-free days for patients with NAFLD were non-inferior to those without (16 days, IQR 10.5-19.5 versus 12 days, IQR 0-18.0, p=0.03). Regarding secondary outcomes, both index hospitalisation and 1-year outcomes were non-inferior between patients with NAFLD and those with normal liver architecture. This study demonstrates that mild-moderate severity NAFLD may not be a contraindication to lung transplantation.

Esophageal disease in lung transplant patients.

There is a very well-established and complex interplay between gastroesophageal reflux and lung disease. This is particularly true in end-stage lung disease and post-lung transplant patients. Numerous studies have shown that in patients who are undergoing pre-lung transplant evaluations for diseases such as idiopathic pulmonary fibrosis (IPF), emphysema, connective tissue disease, there is a high prevalence of gastroesophageal reflux and esophageal dysmotility. Post-lung transplant, many of the reflux issues persist or worsen, and there is some evidence to suggest that this leads to worsened long-term allograft function and bronchiolitis obliterans. Anti-reflux operations in patients with lung disease have been shown to be safe in both the pre and post-lung transplant setting and lead to improved reflux symptoms, as well as protecting against reflux induced allograft dysfunction in the post-lung transplant patients. Barrett's esophagus and esophageal malignancy are also not unheard of in these patients, and select patients may benefit from operative intervention. This review discusses the links between gastroesophageal reflux and lung transplant patients in both the pre and post-transplant setting. We also review the approach to the workup of esophageal disease in the pre-lung transplant setting as well as the surgical management of this unique group of patients.

Preserving NLST mortality benefits and acceptable morbidity for lung cancer surgery in a community hospital.

BACKGROUND AND OBJECTIVES: The aim of this study was to demonstrate whether academic thoracic surgeons could achieve morbidity and mortality rates in community hospitals equivalent to those seen in National Lung Screening Trial (NLST). METHODS: This was a retrospective review of community hospital lung cancer procedures for clinical Stage I-III non-small-cell lung cancers from 2007 through 2014. Variables include age, comorbidities, computed tomography (CT) characterization, and operative techniques. RESULTS: There were 177 patients who had lung cancers removed by a minimally invasive approach (79%), including lobectomy in 127 (72%), segmentectomy in 4 (2%), and wedge-resections in 46 (26%). The median patient age was 71 years (interquartile range [IQR], 63-76). The cohort was primarily female (58%), clinical Stage I (82%), with a median tumor size of 2.3 cm (IQR, 1.5-3.3). The median length of stay was 6 days (range: 1-35). Complications were experienced by 78 (44.1%) patients, most commonly atrial fibrillation in 20 (11.3%) followed by air-leak in 19 (10.7%). There were no in-hospital deaths. Tumor location and extent of resection were associated with complications, while larger tumor size, margin contour, and resection method were associated with air-leak (all p < 0.05). Higher clinical stage and larger tumor size were associated with occult Stage III disease (both p < 0.05). CONCLUSIONS: The low morbidity and mortality rates from the NLST were achievable in a community setting for early-stage lung cancer. Characterization of cancers using CT imaging identified factors most commonly associated with postoperative complications and the presence of occult Stage III disease.

N-myc-interactor mediates microbiome induced epithelial to mesenchymal transition and is associated with chronic lung allograft dysfunction.

BACKGROUND: Recent evidence suggests a role for lung microbiome in occurrence of chronic lung allograft dysfunction (CLAD). However, the mechanisms linking the microbiome to CLAD are poorly delineated. We investigated a possible mechanism involved in microbial modulation of mucosal response leading to CLAD with the hypothesis that a Proteobacteria dominant lung microbiome would inhibit N-myc-interactor (NMI) expression and induce epithelial to mesenchymal transition (EMT). METHODS: Explant CLAD, non-CLAD, and healthy nontransplant lung tissue were collected, as well as bronchoalveolar lavage from 14 CLAD and matched non-CLAD subjects, which were followed by 16S rRNA amplicon sequencing and quantitative polymerase chain reaction (PCR) analysis. Pseudomonas aeruginosa (PsA) or PsA-lipopolysaccharide was cocultured with primary human bronchial epithelial cells (PBEC). Western blot analysis and quantitative reverse transcription (qRT) PCR was performed to evaluate NMI expression and EMT in explants and in PsA-exposed PBECs. These experiments were repeated after siRNA silencing and upregulation (plasmid vector) of EMT regulator NMI. RESULTS: 16S rRNA amplicon analyses revealed that CLAD patients have a higher abundance of phyla Proteobacteria and reduced abundance of the phyla Bacteroidetes. At the genera level, CLAD subjects had an increased abundance of genera Pseudomonas and reduced Prevotella. Human CLAD airway cells showed a downregulation of the N-myc-interactor gene and presence of EMT. Furthermore, exposure of human primary bronchial epithelial cells to PsA resulted in downregulation of NMI and induction of an EMT phenotype while NMI upregulation resulted in attenuation of this PsA-induced EMT response. CONCLUSIONS: CLAD is associated with increased bacterial biomass and a Proteobacteria enriched airway microbiome and EMT. Proteobacteria such as PsA induces EMT in human bronchial epithelial cells via NMI, demonstrating a newly uncovered mechanism by which the microbiome induces cellular metaplasia.

Controlled apneic tracheostomy in patients with coronavirus disease 2019 (COVID-19).

OBJECTIVE: To develop a team-based institutional infrastructure for navigating management of a novel disease, to determine a safe and effective approach for performing tracheostomies in patients with COVID-19 respiratory failure, and to review outcomes of patients and health care personnel following implementation of this approach. METHODS: An interdisciplinary Task Force was constructed to develop innovative strategies for management of a novel disease. A single-institution, prospective, nonrandomized cohort study was then conducted on patients with coronavirus disease 2019 (COVID-19) respiratory failure who underwent tracheostomy using an induced bedside apneic technique at a tertiary care academic institution between April 27, 2020, and June 30, 2020. RESULTS: In total, 28 patients underwent tracheostomy with induced apnea. The median lowest procedural oxygen saturation was 95%. The median number of ventilated days following tracheostomy was 11. There were 3 mortalities (11%) due to sepsis and multiorgan failure; of 25 surviving patients, 100% were successfully discharged from the hospital and 76% are decannulated, with a median time of 26 days from tracheostomy to decannulation (range 12-57). There was no symptomatic disease transmission to health care personnel on the COVID-19 Tracheostomy Team. CONCLUSIONS: Patients with respiratory failure from COVID-19 disease may benefit from tracheostomy. This can be completed effectively and safely without viral transmission to health care personnel. Performing tracheostomies earlier in the course of disease may expedite patient recovery and improve intensive care unit resource use. The creation of a collaborative Task Force is an effective strategic approach for management of novel disease.

Left ventricle unloading strategies in ECMO: A single-center experience.

INTRODUCTION: Extracorporeal membrane oxygenation (ECMO) is a life-saving technology capable of restoring perfusion but is not without significant complications that limit its realizable therapeutic benefit. ECMO-induced hemodynamics increase cardiac afterload risking left ventricular distention and impaired cardiac recovery. To mitigate potentially harmful effects, multiple strategies to unload the left ventricle (LV) are used in clinical practice but data supporting the optimal approach is presently lacking. MATERIALS & METHODS: We reviewed outcomes of our ECMO population from September 2015 through January 2019 to determine if our LV unloading strategies were associated with patient outcomes. We compared reactive (Group 1, n = 30) versus immediate (Group 2, n = 33) LV unloading and then compared patients unloaded with an Impella CP (n = 19) versus an intra-aortic balloon pump (IABP, n = 16), analyzing survival and ECMO-related complications. RESULTS: Survival was similar between Groups 1 and 2 (33 vs 42%, P = .426) with Group 2 experiencing more clinically-significant hemorrhage (40 vs. 67%, P = .034). Survival and ECMO-related complications were similar between patients unloaded with an Impella versus an IABP. However, the Impella group exhibited a higher rate of survival (37%) than predicted by their median SAVE score (18%). DISCUSSION: Based on this analysis, reactive unloading appears to be a viable strategy while venting with the Impella CP provides better than anticipated survival. Our findings correlate with recent large cohort studies and motivate further work to design clinical guidelines and future trial design.

The impact of hepatitis C viremic donor lung allograft characteristics on post-transplantation outcomes.

BACKGROUND: There is a low utilization rate of donated donor lungs. Historically, transplantation of lungs from hepatitis C-viremic donors to hepatitis C (HCV) negative recipients was avoided due to concern for worse graft survival. In the past few years with the advent of direct acting antiviral (DAA) therapy, there are emerging data suggesting the safety and efficacy of transplanting thoracic organs from HCV-viremic donors. This study assessed the differences in donor characteristics and allograft-specific clinical features at the time of organ offer and investigated whether these variables differed in HCV-viremic versus HCV-negative donors and impacted recipient outcomes. METHODS: We conducted a single-center, retrospective cohort study of adult patients who underwent a lung transplant at Brigham and Women's Hospital between March 2017 and October 2018. Patients were stratified based on their donor HCV status (HCV-viremic versus HCV-negative). Donor and allograft-specific characteristics and clinical features including chest imaging and bronchoscopy reports, respiratory cultures, and the donor's oxygenation as measured by the arterial partial pressure of oxygen (PaO2) were collected as well as recipient baseline characteristics and transplant outcomes. RESULTS: During the study period, 42 and 57 lung transplants were performed from HCV-viremic and HCV-negative donors, respectively. Donor age was similar in both cohorts. More HCV-viremic donors died from drug intoxication (71% versus 19%, P=0.0001) and had a history of cigarette use (83% versus 5%, P=0.0001) and drug use (76% versus 49%, P=0.007). There were differences in the baseline recipient characteristics including a lower median lung allocation score in the HCV-viremic cohort. The organ-specific clinical characteristics including the terminal PaO2, chest imaging and bronchoscopy findings, and evidence of pulmonary infection were similar between the two cohorts. The recipient outcomes overall were excellent and did not differ significantly in both cohorts in terms of graft and patient survival at 6 and 12 months. CONCLUSIONS: Despite a greater proportion of HCV-viremic donors being increased risk with a history of drug and cigarette use and having died as a result of drug intoxication, the quality of the HCV-viremic donor organs did not differ from the HCV-negative donor organs or impact graft and recipient survival. Due to an increasing number of transplants from increased risk donors and in order to develop safe and effective protocols to perform lung transplants from HCV-infected donors, further characterization of the donor and allograft-specific clinical features and longer-term recipient outcomes is greatly needed.

Heart and Lung Transplants from HCV-Infected Donors to Uninfected Recipients.

BACKGROUND: Hearts and lungs from donors with hepatitis C viremia are typically not transplanted. The advent of direct-acting antiviral agents to treat hepatitis C virus (HCV) infection has raised the possibility of substantially increasing the donor organ pool by enabling the transplantation of hearts and lungs from HCV-infected donors into recipients who do not have HCV infection. METHODS: We conducted a trial involving transplantation of hearts and lungs from donors who had hepatitis C viremia, irrespective of HCV genotype, to adults without HCV infection. Sofosbuvir-velpatasvir, a pangenotypic direct-acting antiviral regimen, was preemptively administered to the organ recipients for 4 weeks, beginning within a few hours after transplantation, to block viral replication. The primary outcome was a composite of a sustained virologic response at 12 weeks after completion of antiviral therapy for HCV infection and graft survival at 6 months after transplantation. RESULTS: A total of 44 patients were enrolled: 36 received lung transplants and 8 received heart transplants. The median viral load in the HCV-infected donors was 890,000 IU per milliliter (interquartile range, 276,000 to 4.63 million). The HCV genotypes were genotype 1 (in 61% of the donors), genotype 2 (in 17%), genotype 3 (in 17%), and indeterminate (in 5%). A total of 42 of 44 recipients (95%) had a detectable hepatitis C viral load immediately after transplantation, with a median of 1800 IU per milliliter (interquartile range, 800 to 6180). Of the first 35 patients enrolled who had completed 6 months of follow-up, all 35 patients (100%; exact 95% confidence interval, 90 to 100) were alive and had excellent graft function and an undetectable hepatitis C viral load at 6 months after transplantation; the viral load became undetectable by approximately 2 weeks after transplantation, and it subsequently remained undetectable in all patients. No treatment-related serious adverse events were identified. More cases of acute cellular rejection for which treatment was indicated occurred in the HCV-infected lung-transplant recipients than in a cohort of patients who received lung transplants from donors who did not have HCV infection. This difference was not significant after adjustment for possible confounders. CONCLUSIONS: In patients without HCV infection who received a heart or lung transplant from donors with hepatitis C viremia, treatment with an antiviral regimen for 4 weeks, initiated within a few hours after transplantation, prevented the establishment of HCV infection. (Funded by the Mendez National Institute of Transplantation Foundation and others; DONATE HCV ClinicalTrials.gov number, NCT03086044.).

Propensity Score Adjusted Comparison of Minimally Invasive versus Open Thymectomy in the Management of Early Stage Thymoma.

BACKGROUND: The benefits of minimally invasive versus open thymectomy for the management of thymoma are debatable. Further, patient factors contributing to the selection of operative technique are not well elucidated. We aim to identify the association between baseline patient characteristics with choice of surgical approach. METHODS: Medical records of early stage thymoma (stages I and II) patients undergoing thymectomy between 2005 and 2015 at a single center were identified. Baseline characteristics and surgical outcomes such as prolonged length of stay (LOS ≥ 4 days), 90-day postoperative morbidity, completeness of resection, and recurrence or mortality free rates were compared by surgical approach. RESULTS: Fifty-three patients underwent thymectomy (34 open [64.15%] vs. 19 minimally invasive [35.85%]). There were no statistical differences between the two surgical approaches in demographic variables, smoking status, lung function, comorbidity, tumor size, or staging. Open thymectomy had significantly prolonged LOS (≥4 days) compared with minimally invasive procedures (odds ratio: 11.65; p < 0.01). There were no significant differences in postoperative composite morbidity (p = 0.56), positive margin (p = 0.40), tumor within 0.1 cm of resection margin (p = 0.38), and survival probability estimates (log rank test; p = 0.48) between the two groups. CONCLUSION: Baseline patient characteristics were not associated with surgical approach selected for thymectomy. Minimally invasive thymectomy patients had shorter LOS but no significant differences in 90-day composite morbidity and recurrence or mortality. Larger multicenter studies are needed to evaluate factors contributing to patient selection for each approach, which may include surgeon preference.

Utility and reproducibility of 3-dimensional printed models in pre-operative planning of complex thoracic tumors.

BACKGROUND AND OBJECTIVES: 3D-printed models are increasingly used for surgical planning. We assessed the utility, accuracy, and reproducibility of 3D printing to assist visualization of complex thoracic tumors for surgical planning. METHODS: Models were created from pre-operative images for three patients using a standard radiology 3D workstation. Operating surgeons assessed model utility using the Gillespie scale (1 = inferior to 4 = superior), and accuracy compared to intraoperative findings. Model variability was assessed for one patient for whom two models were created independently. The models were compared subjectively by surgeons and quantitatively based on overlap of depicted tissues, and differences in tumor volume and proximity to tissues. RESULTS: Models were superior to imaging and 3D visualization for surgical planning (mean score = 3.4), particularly for determining surgical approach (score = 4) and resectability (score = 3.7). Model accuracy was good to excellent. In the two models created for one patient, tissue volumes overlapped by >86.5%, and tumor volume and area of tissues ≤1 mm to the tumor differed by <15% and <1.8 cm2 , respectively. Surgeons considered these differences to have negligible effect on surgical planning. CONCLUSION: 3D printing assists surgical planning for complex thoracic tumors. Models can be created by radiologists using routine practice tools with sufficient accuracy and clinically negligible variability.