Fibroblasts in Diabetic Foot Ulcers.

Fibroblasts are stromal cells ubiquitously distributed in the body of nearly every organ tissue. These cells were previously considered to be "passive cells", solely responsible for ensuring the turnover of the extracellular matrix (ECM). However, their versatility, including their ability to switch phenotypes in response to tissue injury and dynamic activity in the maintenance of tissue specific homeostasis and integrity have been recently revealed by the innovation of technological tools such as genetically modified mouse models and single cell analysis. These highly plastic and heterogeneous cells equipped with multifaceted functions including the regulation of angiogenesis, inflammation as well as their innate stemness characteristics, play a central role in the delicately regulated process of wound healing. Fibroblast dysregulation underlies many chronic conditions, including cardiovascular diseases, cancer, inflammatory diseases, and diabetes mellitus (DM), which represent the current major causes of morbidity and mortality worldwide. Diabetic foot ulcer (DFU), one of the most severe complications of DM affects 40 to 60 million people. Chronic non-healing DFU wounds expose patients to substantial sequelae including infections, gangrene, amputation, and death. A complete understanding of the pathophysiology of DFU and targeting pathways involved in the dysregulation of fibroblasts are required for the development of innovative new therapeutic treatments, critically needed for these patients.

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

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

CT imaging findings in lung transplant recipients with COVID-19.

OBJECTIVES: Our goal was to compare the chest computed tomography (CT) imaging findings of COVID-19 in lung transplant recipients (LTR) and a group of non-transplanted controls (NTC). METHODS: This retrospective study included 51 consecutive LTR hospitalized with COVID-19 from two centers. A total of 75 NTC were included for comparison. Images were classified regarding the standardized RSNA category, main pattern of lung attenuation, and longitudinal and axial distribution. Quantitative CT (QCT) analysis was performed to evaluate percentage of high attenuation areas (%HAA, threshold -250 to -700 HU). CT scoring was used to measure severity of parenchymal abnormalities. RESULTS: The imaging findings of COVID-19 in LTR were significantly different from controls regarding the RSNA classification and pattern of lung attenuation. LTR had a significantly higher proportion of patients with an indeterminate pattern on CT (0.31 vs. 0.11, p = 0.014). The most frequent pattern of attenuation in LTR was predominantly consolidation (0.39 vs. 0.22, p = 0.144) followed by a mixed pattern of ground-glass opacities (GGO) and consolidation (0.37 vs. 0.20, adjusted p = 0.102). On the other hand, the most common pattern in NTC was GGO predominant (0.58 vs. 0.24 of LTR, p = 0.001). LTR had significantly more severe parenchymal disease measured by CT score and %HAA by QCT (0.372 ± 0.08 vs. 0.148 ± 0.06, p < 0.001). CONCLUSION: The most frequent finding of COVID-19 in LTR is a predominant pattern of consolidation. Compared to NTC, LTR more frequently demonstrated an indeterminate pattern according to the RSNA classification and more extensive lung abnormalities on QCT and semi-quantitative scoring. KEY POINTS: • The most common CT finding of COVID-19 in LTR is a predominant pattern of consolidation followed by a mixed pattern of GGO and consolidation, while controls more often have a predominant pattern of GGO. • LTR more often presents with an indeterminate pattern of COVID-19 by RSNA classification than controls; therefore, molecular testing for COVID-19 is essential for LTR presenting with lower airway infection independently of imaging findings. • LTR had more extensive disease by semi-quantitative CT score and increased percentage areas of high attenuation on QCT.

Acute transcutaneous electrical stimulation (TES) augments esophageal contractility in patients with weak peristalsis.

BACKGROUND: Lung transplantation (LTx) remains controversial in patients with absent peristalsis (AP) given the increased risk for gastroesophageal reflux (GER), and chronic lung allograft dysfunction. Furthermore, specific treatments to facilitate LTx in those with AP have not been widely described. Transcutaneous Electrical Stimulation (TES) has been reported to improve foregut contractility in LTx patients and therefore we hypothesize that TES may augment the esophageal motility of patients with ineffective esophageal motility (IEM). METHODS: We included 49 patients, 14 with IEM, 5 with AP, and 30 with normal motility. All subjects underwent standard high-resolution manometry and intraluminal impedance (HRIM) with additional swallows as TES was delivered. RESULTS: TES induced a universal impedance change observable in real-time by a characteristic spike activity. TES significantly augmented the contractile vigor of the esophagus measured by the distal contractile integral (DCI) in patients with IEM [median DCI (IQR) 0 (238) mmHg-cm-s off TES vs. 333 (858) mmHg-cm-s on TES; p = .01] and normal peristalsis [median DCI (IQR) 1545 (1840) mmHg-cm-s off TES vs. 2109 (2082) mmHg-cm-s on TES; p = .01]. Interestingly, TES induced measurable contractile activity (DCI > 100 mmHg-cm-s) in three out of five patients with AP [median DCI (IQR) 0 (0) mmHg-cm-s off TES vs. 0 (182) mmHg-cm-s on TES; p < .001]. CONCLUSION: TES acutely augmented contractile vigor in patients with normal and weak/ AP. The use of TES may positively impact LTx candidacy, and outcomes for patients with IEM/AP. Nevertheless, further studies are needed to determine the long-term effects of TES in this patient population.

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

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

Lung transplantation for acute exacerbation of interstitial lung disease.

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

Hyperammonemia After Lung Transplantation: Systematic Review and a Mini Case Series.

Background: Hyperammonemia after lung transplantation (HALT) is a rare but serious complication with high mortality. This systematic review delineates possible etiologies of HALT and highlights successful strategies used to manage this fatal complication. Methods: Seven biomedical databases and grey literature sources were searched using keywords relevant to hyperammonemia and lung transplantation for publications between 1995 and 2020. Additionally, we retrospectively analyzed HALT cases managed at our institution between January 2016 and August 2018. Results: The systematic review resulted in 18 studies with 40 individual cases. The mean peak ammonia level was 769 µmol/L at a mean of 14.1 days post-transplant. The mortality due to HALT was 57.5%. In our cohort of 120 lung transplants performed, four cases of HALT were identified. The mean peak ammonia level was 180.5 µmol/L at a mean of 11 days after transplantation. HALT in all four patients was successfully treated using a multimodal approach with an overall mortality of 25%. Conclusion: The incidence of HALT (3.3%) in our institution is comparable to prior reports. Nonetheless, ammonia levels in our cohort were not as high as previously reported and peaked earlier. We attributed these significant differences to early recognition and prompt institution of multimodal treatment approach.

Corrigendum: Hyperammonemia After Lung Transplantation: Systematic Review and a Mini Case Series.

[This corrects the article DOI: 10.3389/ti.2022.10433.].

A novel injury site-natural antibody targeted complement inhibitor protects against lung transplant injury.

Complement is known to play a role in ischemia and reperfusion injury (IRI). A general paradigm is that complement is activated by self-reactive natural IgM antibodies (nAbs), after they engage postischemic neoepitopes. However, a role for nAbs in lung transplantation (LTx) has not been explored. Using mouse models of LTx, we investigated the role of two postischemic neoepitopes, modified annexin IV (B4) and a subset of phospholipids (C2), in LTx. Antibody deficient Rag1-/- recipient mice were protected from LTx IRI. Reconstitution with either B4 or C2nAb restored IRI, with C2 significantly more effective than B4 nAb. Based on these information, we developed/characterized a novel complement inhibitor composed of single-chain antibody (scFv) derived from the C2 nAb linked to Crry (C2scFv-Crry), a murine inhibitor of C3 activation. Using an allogeneic LTx, in which recipients contain a full nAb repertoire, C2scFv-Crry targeted to the LTx, inhibited IRI, and delayed acute rejection. Finally, we demonstrate the expression of the C2 neoepitope in human donor lungs, highlighting the translational potential of this approach.

Patient and Procedural Determinants of Postoperative Pain Trajectories.

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

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

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

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

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

Successful bridge to lung transplantation with transcatheter aortic valve replacement.

End-stage lung disease and advanced cardiac conditions are frequently seen together and represent a clinical dilemma. Even though both issues may be amenable to surgical management, combining lung transplant with surgical valve repair is rarely done and theoretically associated with increased morbidity and mortality risks, especially in elderly patients. Here, we describe 2 patients presenting with end-stage lung disease and significant aortic stenosis who were successfully bridged to lung transplant via transcatheter aortic valve replacement. Patient 1 was a 66-year-old man who underwent a double lung transplant 56 days after transcatheter aortic valve replacement. Patient 2 was a 70-year-old man who underwent a single right lung transplant 103 days after transcatheter aortic valve replacement. Both patients had uneventful postoperative courses and are alive at the 1-year time point with excellent performance status. This report suggests that transcatheter aortic valve replacement may favorably impact lung transplant candidacy for patients with end-stage lung disease in the setting of severe aortic stenosis, likely representing a better alternative to concomitant aortic valve replacement and lung transplant in elderly patients.

Enhanced Mitochondrial DNA Repair Resuscitates Transplantable Lungs Donated After Circulatory Death.

BACKGROUND: Transplantation of lungs procured after donation after circulatory death (DCD) is challenging because postmortem metabolic degradation may engender susceptibility to ischemia-reperfusion (IR) injury. Because oxidative mitochondrial DNA (mtDNA) damage has been linked to endothelial barrier disruption in other models of IR injury, here we used a fusion protein construct targeting the DNA repair 8-oxoguanine DNA glycosylase-1 (OGG1) to mitochondria (mtOGG1) to determine if enhanced repair of mtDNA damage attenuates endothelial barrier dysfunction after IR injury in a rat model of lung procurement after DCD. MATERIALS AND METHODS: Lungs excised from donor rats 1 h after cardiac death were cold stored for 2 h after which they were perfused ex vivo in the absence and presence of mt-OGG1 or an inactive mt-OGG1 mutant. Lung endothelial barrier function and mtDNA integrity were determined during and at the end of perfusion, respectively. RESULTS AND CONCLUSIONS: Mitochondria-targeted OGG1 attenuated indices of lung endothelial dysfunction incurred after a 1h post-mortem period. Oxidative lung tissue mtDNA damage as well as accumulation of proinflammatory mtDNA fragments in lung perfusate, but not nuclear DNA fragments, also were reduced by mitochondria-targeted OGG1. A repair-deficient mt-OGG1 mutant failed to protect lungs from the adverse effects of DCD procurement. CONCLUSIONS: These findings suggest that endothelial barrier dysfunction in lungs procured after DCD is driven by mtDNA damage and point to strategies to enhance mtDNA repair in concert with EVLP as a means of alleviating DCD-related lung IR injury.

Bivalirudin and Alteplase for Pulmonary Embolism Requiring Veno-Arterial Extracorporeal Membrane Oxygenation in an Adolescent.

Saddle pulmonary embolism (PE) remains a challenge to diagnose and manage in pediatric patients. Current literature encourages early consideration of veno-arterial extracorporeal membrane oxygenation (VA-ECMO) in high-risk PE patients with impending right ventricular failure. We present a 17-year-old patient who was admitted to a pediatric cardiac intensive care unit with saddle PE requiring emergent VA-ECMO support because of cardiovascular collapse. Despite anticoagulation with bivalirudin and receiving systemic thrombolysis with alteplase, the clot burden was persistent with minimal improvement in right ventricular function. We proceeded to catheter thrombolysis while on VA-ECMO. This ultimately led to a successful resolution of the PE and allowed for weaning off VA-ECMO. PE is rare in children compared with adults, and pediatricians may be unaware of therapies becoming increasingly used in adults such as the use of VA-ECMO, with systemic and local thrombolysis. The concurrent use of a direct thrombin inhibitor for ECMO anticoagulation alongside the thrombolysis is a novel combination in this condition and age-group.

Pre-operative therapeutic plasma Exchange and intravenous immune globulin for the treatment of heparin induced thrombocytopenia in a lung transplant recipient.

Lung transplantation surgery often relies on the use of intraoperative extracorporeal membrane oxygenation (ECMO) and necessitates the need for high dose anticoagulation. Heparin induced thrombocytopenia complicates intraoperative anticoagulation management during lung transplant surgery requiring ECMO. Though other anticoagulants such as argatroban and bivalrudin are utilized for the treatment of Heparin Induced Thrombocytopenia (HIT), the lack of reversal agents makes it difficult to use these agents intraoperatively in cases with high bleeding risk. This is especially true in patients with end stage fibrotic lung disease with calcified mediastinal lymphadenopathy and pulmonary hypertension undergoing lung transplantation. Here we describe a case of HIT in a patient with Sarcoidosis listed for lung transplant who was treated with Therapeutic Plasma Exchange and Intravenous Immune globulin preoperatively and successfully underwent lung transplantation with the use of intraoperative venoarterial ECMO and heparin anticoagulation.

The Evolving Role of Extracorporeal Membrane Oxygenation in Lung Transplantation: Implications for Anesthetic Management.

Lung transplantation has become an accepted therapy for most causes of end-stage lung disease. Between 30 to 50% of lung transplants require extracorporeal life support (ECLS). In many lung transplantation centers, extracorporeal membrane oxygenation (ECMO) is replacing cardiopulmonary bypass (CPB) as the primary choice for intraoperative ECLS. This review will discuss the evolving role of ECMO in lung transplantation and its implications for anesthetic management.

Towards donor lung recovery-gene expression changes during ex vivo lung perfusion of human lungs.

We and others have demonstrated that acellular normothermic ex vivo lung perfusion of high-risk donor lungs can result in posttransplant outcomes equivalent to that of contemporaneous lung transplantation using standard donor lungs. However, the mechanism of this effect remains unclear. Given the restoration of cellular metabolic activity during normothermic perfusion, one possibility is that of lung healing via natural innate recovery mechanisms. We explored this by examining the gene expression changes occurring in human lungs during ex vivo lung perfusion. Human lungs clinically rejected for transplantation were perfused for 12 hours of EVLP with biopsies taken at the start, at 1 hour, at 3 hours, and then every 3 hours thereafter to 12 hours. Temporal changes were identified in 2585 genes using the Short Time-series Expression Miner and used for pathway analysis. Despite increases in endothelial markers of inflammation, circulating leukocyte cell-specific gene expression fell over 12 hours of ex vivo lung perfusion (EVLP), suggesting an interrupted inflammation response secondary to washout of circulating leukocytes. Analysis of these gene changes suggests lung recovery follows specific stages: cellular death, cellular preservation, cellular reorganization, and cellular invasion. EVLP may improve posttransplant lung function by washout of leukocytes and facilitating innate mechanisms of repair.

Performance of Endobronchial Ultrasound-Guided Transbronchial Needle Aspiration for the Diagnosis of Isolated Mediastinal and Hilar Lymphadenopathy.

BACKGROUND: Although many studies have assessed the diagnostic utility of endobronchial ultrasound-guided transbronchial needle aspiration (EBUS-TBNA) in the context of a specific disease, few studies have assessed the overall diagnostic yield, sensitivity, and negative predictive value in patients with isolated mediastinal and hilar lymphadenopathy (IMHL). OBJECTIVE: We evaluated the performance of EBUS-TBNA for diagnosing IMHL in a population with a high prevalence of concurrent or preexisting non-pulmonary malignancy. METHODS: A retrospective chart review of patients who underwent EBUS-TBNA from October 2008 to April 2014 was performed to identify patients with IMHL. Patients with known or suspected primary pulmonary malignancy were excluded. When available, EBUS-TBNA results were cross-referenced with further diagnostic investigation or clinical diagnosis based on follow-up. RESULTS: EBUS-TBNA was used to sample 765 lymph nodes from 350 patients. One hundred and fourteen (33.3%) patients had a concurrent or preexisting non-pulmonary malignancy. The overall yield of EBUS-TBNA for specific diagnosis was 300/350 (86%). The diagnostic yield for sarcoidosis, lymphoproliferative disease, metastatic lymphadenopathy from extrathoracic malignancy, and necrotizing granuloma was 123/149 (83%), 27/33 (82%), 20/25 (80%), and 13/19 (68%), respectively. Amongst 50 patients with non-diagnostic EBUS-TBNA, 25 yielded an insufficient sample and another 25 yielded only benign lymphoid material which was not representative of the underlying pathology. Overall, EBUS-TBNA had a sensitivity of 89%, a diagnostic yield of 86%, and a negative predictive value of 79%. CONCLUSION: For patients with isolated hilar or mediastinal lymphadenopathy and a high background prevalence of concurrent and preexisting non-pulmonary malignancy, EBUS-TBNA is a reliable first-line diagnostic investigation.