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BACKGROUND: Primary spontaneous pneumothorax (PSP) is a common disease where surgery is indicated for persistant air leak or recurrent pneumothorax. We studied the outcomes of PSP-surgery over a 28 year period in a whole nation. MATERIALS AND METHODS: A retrospective study on 386 patients (median age 24 years, 78% males) that underwent 430 PSP surgeries at Landspitali University Hospital 1991-2018. Annual incidence of the procedure was calculated and previous medical history, indication and type of surgery, complications and length of hospital stay were registered. Patients in four 7 year periods were compared, recurrent pneumothoraces requiring reoperation (median follow-up 16 years) registered and predictors of reoperation identified with logistic regression. RESULTS: Annually 14.5 PSP surgeries (median, range 9-27) were performed; the incidence decreasing by 2.9% per year on average. Every other patient smoked and 77% of surgeries were performed with video assisted thoracocopic surgery (VATS). The most common early complications (

BACKGROUND To determine the discriminative accuracy and calibration of EuroSCORE II in relation to age, sex, and surgical risk in a large nationwide coronary artery bypass grafting (CABG) cohort. METHODS All 14118 patients undergoing isolated CABG in Sweden during 2012–2017 were included. Individual patient data were taken from the SWEDEHEART registry. Patients were divided by age (8%). Discriminative accuracy was determined by the area under the receiver operating characteristic curve (AUC) and calibration by the observed/estimated (O/E) mortality ratio at 30 days. RESULTS AUC and O/E ratio were 0.82 (95% CI: 0.79–0.85) and 0.58 (0.50–0.66) overall, 0.82 (0.79–0.86) and 0.57 (0.48–0.66) in men, and 0.79 (0.73–0.85) and 0.60 (0.47–0.75) in women. Regarding age, discriminative accuracy was highest in patients aged 60–69 years (AUC: 0.86 [0.80–0.93]) but was satisfactory in all groups (AUC: 0.74–0.80). O/E ratio varied from 0.26 for patients >60 years to 0.90 for patients >80 years. Regarding surgical risk, AUC and O/E ratio were 0.63 (0.44–0.83) and 0.18 (0.09–0.30) in low-risk patients, 0.60 (0.55–0.66) and 0.57 (0.46–0.68) in intermediate-risk patients, and 0.78 (0.73–0.83) and 0.78 (0.64–0.92) in high-risk patients. CONCLUSIONS EuroSCORE II had good discriminative accuracy independently of sex and age, but markedly overestimated mortality risk, especially in younger patients. Accuracy and calibration were better in high-risk patients than in low-risk and intermediate-risk patients.

OBJECTIVES Perioperative stroke is a severe complication of cardiac surgery. We assessed the incidence of stroke over time, the association between stroke and mortality and identified preoperative factors independently associated with perioperative stroke, in a large nationwide cardiac surgery population. METHODS All patients who underwent coronary artery bypass grafting in Sweden 2006–2017 were included in a registry-based observational cohort study based on prospectively collected data. Multivariable logistic and Cox regression models were used to assess associations between perioperative stroke and mortality and to identify factors associated with stroke. The median follow-up was 6 years (range 0–12). RESULTS There were 441 perioperative strokes in 36 898 patients. The mean incidence was 1.2% and decreased marginally over time [adjusted odds ratio (OR) 0.97 per year (95% confidence interval 0.94–1.00), P = 0.035]. Stroke patients had a higher overall mortality risk during follow-up [adjusted hazard ratio 2.30 (2.00–2.64), P < 0.001], with the highest risk during the first 30 postoperative days [adjusted hazard ratio (7.29 (5.58–9.54), P < 0.001]. The strongest independent preoperative factors associated with stroke were prior cardiac surgery [adjusted OR 2.89 (1.40–5.96)], critical preoperative condition [adjusted OR 2.55 (1.73–3.76)], previous stroke [adjusted OR 1.77 (1.35–2.33)], preoperative angina requiring intravenous nitrates [adjusted OR 1.67 (1.28–2.17)], peripheral vascular disease [OR 1.63 (1.25–2.13)] and advanced age [OR 1.05 (1.03–1.06) per year]. CONCLUSIONS The incidence of perioperative stroke after coronary artery bypass grafting has remained stable. Patients with perioperative stroke had a markedly higher adjusted risk of death early after surgery. The risk declined over time but remained higher during the entire follow-up period.

We report a patient with acute respiratory syndrome coronavirus 2 infection and irreversible lung destruction who underwent successful lung transplantation after 138 days of bridging with extracorporeal membrane oxygenation support. The case exemplifies that lung transplantation might be a possibility after very long-term Coronavirus disease 2019 care, even if the patient is initially unsuitable. Patient consent was acquired before writing the case report.

Introduction: Idiopathic pulmonary fibrosis (IPF) involves extensive remodeling of the extracellular matrix (ECM), primarily in the periphery of the lung. This leads to altered mechanical properties, which in turn results in altered mechanical stimulation of the cells. In stiffer and less elastic ECM found in IPF, fibroblasts are thus exposed to altered strain compared to a healthy ECM. Our aim is to investigate the impact of mechanical stimulation on fibroblasts activity in IPF. Methods: IPF and healthy distal lung tissue were decellularized in slices (350 mm) to produce acellular lung scaffolds. The scaffolds were attached to a custom-made device for cyclic stretch built in polydimethylsiloxane and repopulated with healthy primary distal lung fibroblasts. The scaffolds were either exposed to cyclic stretch (0.2 Hz, 10% strain) or cultured under static conditions upto 3 days and analyzed for cell viability, histology, RNA expression, and released mediators. Results: Compared to healthy scaffolds, fibroblasts on IPF scaffolds showed increased metabolic activity, both at static and cyclic stretch condition. Scaffolds under cyclic stretch showed preserved tissue morphology with dispersed elongated fibroblasts shown with H&E staining. Interestingly, we see a shift in released mediators linked to angiogenesis in cyclic stretch cultures, mostly pronounced in IPF scaffolds. Discussion: We demonstrate that we have developed a physiological more relevant ex vivo model to study cellular responses in lung tissue. Our data indicate that there is a change in cellular activity in IPF tissue under cyclic stretch. This allows us to study the effect of alterations in mechanical and matrisome properties in chronic lung disease.

Decellularized tissues offer an excellent approach to study cell-ECM interaction in health and disease. We have used peripheral lung tissue from healthy individuals and idiopathic pulmonary fibrosis (IPF) patients. IPF is characterized by excessive matrix production and stiffening of the tissue. The aim was to examine temporal changes in the original ECM in healthy and IPF scaffolds and how these affect protein production of repopulating fibroblasts. Tissue slices (350µm) were decellularized using CHAPS to generate biological scaffolds, characterized by density, biomechanical properties, histology, and mass spectrometry (MS). Scaffolds were mounted on custom-made holders, to mimic the native setting, seeded with human primary fibroblasts derived from a healthy donor, and cultured using medium supplemented with isotope-labeled Arg and Lys. Repopulated scaffolds were examined as described above to study differences in ECM. Heavy isotope labelling of cultured cells allowed us to follow up- and downregulation of newly synthesized proteins compared to original scaffold due to a mass shift detectable in MS. Interestingly, fibroblasts cultured on IPF scaffolds had a protein production profile overlapping with the profile of the original scaffold. Our biological system allowed us to study temporal differences in protein production in healthy and diseased scaffolds. By culturing under static stretch we created a 3D environment similar to the native situation, strongly influencing the cellular response. This opens up for in depth identification of proteins involved in lung disease and tissue regeneration. Our goal is to identify a combination of factors that can locally trigger a healthy lung regeneration.

In idiopathic pulmonary fibrosis (IPF) structural properties of the extracellular matrix (ECM) are altered and influence cellular responses through cell-matrix interactions. Scaffolds (decellularized tissue) derived from subpleural healthy and IPF lungs were examined regarding biomechanical properties and ECM composition of proteins (the matrisome). Scaffolds were repopulated with healthy fibroblasts cultured under static stretch with heavy isotope amino acids (SILAC), to examine newly synthesized proteins over time. IPF scaffolds were characterized by increased tissue density, stiffness, ultimate force, and differential expressions of matrisome proteins compared to healthy scaffolds. Collagens, proteoglycans, and ECM glycoproteins were increased in IPF scaffolds, however while specific basement membrane (BM) proteins such as laminins and collagen IV were decreased, nidogen-2 was also increased. Findings were confirmed with histology, clearly showing a disorganized BM. Fibroblasts produced scaffold-specific proteins mimicking preexisting scaffold composition, where 11 out of 20 BM proteins were differentially expressed, along with increased periostin and proteoglycans production. We demonstrate how matrisome changes affect fibroblast activity using novel approaches to study temporal differences, where IPF scaffolds support a disorganized BM and upregulation of disease-associated proteins. These matrix-directed cellular responses emphasize the IPF matrisome and specifically the BM components as important factors for disease progression.

Background A large proportion of donor lungs are discarded due to known or presumed organ dysfunction. Ex vivo lung perfusion (EVLP) has proven its value as a tool for discrimination between reversible and irreversible donor lung pathology. However, the long-term outcome after transplantation of lungs after EVLP is essentially unknown. We report short-term and midterm outcomes of recipients who received transplants of EVLP-evaluated lungs. Methods Single-center results of recipients of lungs with prior EVLP were compared with consecutive recipients of non-EVLP lungs (controls) during the same period. Short-term follow-up included time to extubation, time in the intensive care unit, and the presence of primary graft dysfunction at 72 hours postoperatively. Mortality and incidence of chronic lung allograft dysfunction were monitored for up to 4 years after discharge. Results During a 4-year period, 32 pairs of initially rejected donor lungs underwent EVLP. After EVLP, 22 double lungs and 5 single lungs were subsequently transplanted. During this period, 145 patients received transplants of conventional donor lungs that did not have EVLP and constituted the control group. Median time to extubation was 7 hours in the EVLP group and 6 hours in the non-EVLP control group (p = 0.45). Median intensive care unit stay was 4 days vs. 3 days, respectively (p = 0.15). Primary graft dysfunction grade > 1 was present in 14% in the EVLP group and in 12% in the non-EVLP group at 72 hours after transplant. Survival at 1 year was 92% in the EVLP group and 79% in the non-EVLP group. Cumulative survival and freedom from retransplantation or chronic rejection were also comparable between the 2 groups (p = 0.43) when monitored up to 4 years. Conclusions Selected donor lungs rejected for transplantation can be used after EVLP. This technique is effective for selection of transplantable donor lungs. Patients who received lungs evaluated under EVLP have short-term and midterm outcomes comparable to recipients of non-EVLP donor lungs.

Objectives Ex vivo lung perfusion (EVLP) can potentially reduce pulmonary edema. In a pig model with induced pulmonary edema, we evaluated the effect of hemofiltration (HF) during EVLP on lung function, perfusate oncotic pressure, and lung weight. Methods In anesthetized pigs (n = 14), pulmonary edema was induced by a balloon in the left atrium, combined with crystalloid infusion (20 mL/kg), for 2 hours. The lungs were harvested, stored cold for 2 hours, and randomized to EVLP, with or without a hemofilter (HF and noHF groups, respectively, n = 7 for each). EVLP was performed with cellular perfusate at a hematocrit of 10% to 15%. Oncotic pressure, lung performance, and weight were measured before and after 180 minutes of EVLP reconditioning with or without HF. Results After in vivo induction of edema, arterial oxygen tension (Pa o 2)/inspired oxygen fraction (F io 2), and compliance decreased by 63% and 16%, respectively. Pa o 2/F io 2 was considerably improved at first evaluation ex vivo in both groups. HF increased oncotic pressure by 43% and decreased lung weight by 15%. The effects were negligible in the noHF group. Compliance decreased in both groups during reconditioning, although less so in the HF group (P o 2/F io 2, shunt fraction, and oxygen saturation remained unchanged in both groups. Pulmonary flow index decreased in both groups, and was partially reversed by nitroglycerin. Dorsal atelectatic consolidations were seen in both groups. Conclusions In this lung-edema model, EVLP reconditioning with hyperoncotic solution did not affect the degree of lung edema. HF during EVLP increased perfusate oncotic pressure, decreased lung weight with beneficial effects on compliance, but did not improve lung oxygenation capacity.