Background: Population‐based data about the incidence and mortality of patients with aortic dissections ( ADs ) are sparse. Therefore, the hospital incidence and in‐hospital mortality of patients undergoing open or endovascular surgery for type A ADs ( TAADs ) and type B ADs ( TBADs ) in Germany were analyzed on a nationwide basis between 2006 and 2014. Methods and Results: A secondary data analysis of the nationwide diagnosis‐related group statistics, compiled by the German Federal Statistical Office, was performed for patients who were surgically/interventionally treated for AD ( International Classification of Diseases, Tenth Revision, German Modification [ ICD ‐10‐ GM ] codes I71.00‐I71.07; n=20 533). By using specific procedure codes, a distinction between TAAD (n=14 911/72.6%) and TBAD (n=5622/27.4%) could be made. The standardized hospital incidence of surgically/interventionally treated AD was 2.7/100 000 per year, comprising 2.0/100 000 per year for TAAD and 0.7/100 000 per year for TBAD . The in‐hospital mortality of TAAD was 19.5%; and of TBAD, 9.3%. Both the incidence and in‐hospital mortality increased over the 9‐year period. The share of endovascularly treated TBAD increased steadily during the same time interval. A multilevel multivariable analysis revealed that, for TAAD , age and comorbidity were significantly associated with a higher mortality risk. The latter was also true for TBAD . Sex was not significantly associated with mortality. A significant association between higher annual center volume and mortality was found for TAAD , but not for TBAD . Conclusions: This is the first report on hospital incidence and mortality for surgically/interventionally treated AD on a nationwide basis. Overall, in Germany, hospital incidence and mortality of TAAD and TBAD increased over time. In addition, TAAD is performed more safely in high‐volume centers.

OBJECTIVES: Thoracic endovascular aortic repair is the treatment of choice in complicated acute type B aortic dissection. How to infer predissection aortic diameter is not well understood. Our aim was to delineate changes in descending aortic geometry due to dissection. METHODS: Five tertiary centres reviewed their acute aortic dissection type B databases containing 802 patients. All patients who had undergone computed tomography angiography less than 2 years before and immediately after aortic dissection onset were included. We compared the aortic geometry before and after the dissection onset. RESULTS: Altogether 25 patients were included [median age 60 (first quartile 52, third quartile 72) years; 60% men]. In all except 1 patient, the maximum descending aortic diameter was less than 45 mm before aortic dissection onset. The largest increase in diameter induced by the dissection was observed in the proximal descending aorta 28.2 (25.1, 32.1) vs 34.6 (31.3, 39.1) mm (+6.4 mm; +23%; P < 0.001). The thoracic descending aortic length increased after the dissection onset [253.3 (229.3, 271.9) vs 261.3 (247.9, 285.4) mm; P = 0.003]. The predissection aortic diameter of the proximal thoracic descending aorta was 7.9 (5.2, 10.7) mm larger (P < 0.001) than the post-dissection area-derived true-lumen diameter and 2.5 (1.3, 6.1) mm larger than the maximum true-lumen diameter (P < 0.001). CONCLUSIONS: Type B aortic dissection increases the diameter, length and volume of the descending thoracic aorta. The predissection aortic diameter most closely resembles the post-dissection maximum diameter of the true lumen.