Objective:To investigate the risk factors of acute Stanford type B aortic dissection (TBAD) complicated with pleural effusion (PE) and the short-term and long-term outcomes of thoracic endovascular aortic repair (TEVAR).Methods:A case-control study. The clinical and imaging data of 1 083 patients with acute TBAD admitted to the General Hospital of Northern Theater Command from April 2002 to December 2020 were retrospectively analyzed, including 211 cases with pleural effusion and 872 cases without pleural effusion. The baseline analysis of the two groups of patients was performed. The risk factors associated with pleural effusion were analyzed by binary logistic regression, and the results were expressed as odds ratio ( OR) and 95% confidence interval ( CI). According to the quantity of pleural effusion, they were simultaneously divided into small pleural effusion group and medium large pleural effusion group, to compare the short-term and long-term effects of TEVAR patients with different amounts of pleural effusion. Results:The incidence of pericardial effusion (17.5% vs. 3.8%, P<0.001), anemia (21.3% vs. 12.5%, P=0.001), aortic spiral tear (49.8% vs. 37.8%, P=0.002), dissection tear over diaphragm (57.8% vs. 48.1%, P=0.011), serum creatinine [85 (69, 111) vs. 81 (67, 100) μmol/L, P=0.011] and white blood cell levels[(11.3±4.2)×10 9/L vs. (10.3±4.2)×10 9/L, P=0.002] in acute TBAD pleural effusion group were significantly higher than those in non-pleural effusion group, and the hemoglobin level was significantly lower than that in non-pleural effusion group [(128±20) vs. (133±17) g/L, P<0.05]. Logistic stepwise regression analysis showed that pericardial effusion ( OR=5.038,95% CI 2.962-8.568, P<0.001), anemia ( OR=2.047,95% CI 1.361-3.079, P=0.001), spiral tear ( OR=1.551,95% CI 1.030-2.336 , P=0.002) and elevated white blood cell ( OR=1.059,95% CI 1.011-1.102, P=0.005) were independent risk factors for TBAD complicated with pleural effusion. The incidences of all-cause death (4/19 vs. 1.5% vs. 0.9%, P<0.001), aortogenic death (4/19 vs. 0.7% vs. 0.7%, P<0.001) and aortic related adverse events (4/19 vs. 1.5% vs. 1.1%, P<0.001) in patients with large pleural effusion during TEVAR operation were significantly higher than those in patients with small pleural effusion and those without pleural effusion, and the differences were statistically significant. At 1 month follow-up after TEVAR, the incidence of all-cause death (4/16 vs. 3.3% vs. 1.6%, P<0.001), aortogenic death (4/16 vs. 0.8% vs.0.7%, P<0.001), aorta related adverse events (4/16 vs. 4.1% vs. 4.7%, P=0.013) and overall clinical adverse events (4/16 vs.9.8% vs. 6.7%, P=0.014) in the medium and large thoracic group were significantly higher than those in the small pleural effusion group and no pleural effusion group, and the differences were statistically significant. At 1 year follow-up after TEVAR, the incidence of all-cause death (4/15 vs. 4.9% vs. 3.9%, P=0.004), aortogenic death (4/15 vs.2.5% vs. 2.1%, P<0.001), aorta related adverse events (5/15 vs. 11.5% vs. 9.4%, P=0.012) and overall clinical adverse events (5/15 vs. 18.9% vs. 13.1%, P=0.029) in the medium and large thoracic group were significantly higher than those in the small pleural effusion group and no pleural effusion group, and the differences were statistically significant. Conclusions:Single center data showed that pericardial effusion, anemia, spiral tear and elevated white blood cell were independent risk factors for acute TBAD complicated with pleural effusion; the early (1 month) and long-term (1 year) rates of all-cause death, aortic mortality, aortic adverse events and overall clinical adverse events were significantly higher in TBAD patients with moderate pleural effusion after TEVAR, and moderate and large pleural effusion was an independent risk factor for near and long-term aortic related adverse events after TEVAR surgery.