Increasing Incidence of Thoracic Aortic Aneurysm Repair in Germany in the Endovascular Era: Secondary Data Analysis of the Nationwide German DRG Microdata

Objectives: Nationwide population based data on epidemiology and surgical treatment of descending thoracic aortic (DTA) aneurysms are not available for Germany. The aim was to assess the in hospital incidence, and to report outcomes of patients who received surgical treatment. Methods: Data were acquired by analysing the diagnosis related group (DRG) statistics of the German Federal Statistical Office. All inpatient cases of ruptured (rDTA aneurysm, ICD Code I71.1) or non-ruptured DTA aneurysm (nrDTA aneurysm; I71.2) who received thoracic endovascular (TEVAR; OPS procedure code 5-38a.7/70/8/80) or open aortic repair (OAR; OPS 5-384.3) between 2005 and 2014 were included. To adjust for sex, age, medical risk (Elixhauser comorbidity score), type of procedure, and type of admission, a multilevel multivariable regression model with robust error variance was applied. The primary outcome was in hospital mortality; secondary outcomes were organ complications. A volume outcome analysis was performed. Results: A total of 48,098 cases of DTA aneurysm (5,848, 12.2% rDTA aneurysm) were identified. The average age was 69 +/- 12 years. 65.2% were male. Frequent comorbidities were hypertension (74.9%), peripheral artery disease (including abdominal aortic aneurysm, 42.6%), other heart diseases (41.6%), coronary heart disease (26.2%), and renal failure (22.5%). Surgical treatment was received by 4969 patients (10.3%): 4057 TEVAR (81.6%) and 912 OAR (18.4%) procedures. Mortality for rDTA aneurysm was 42.9% (OAR) and 22.3% (TEVAR). It was 10.5% and 3.7% for DTA aneurysm, respectively. Rupture, increasing age, and higher comorbidity score were significantly associated with higher mortality (RR 6.66, 5.33-8.25; 1.28, 1.17-1.40; and 1.06, 1.05-1.08, respectively). Endovascular treatment was associated with lower mortality (RR 0.31, 0.23-0.41). Hospital volume was not significantly associated with in hospital mortality. Conclusions: Eighty per cent of patients treated surgically for a DTA aneurysm receive endovascular therapy, with low peri-operative mortality in non-ruptured cases. Elective endovascular repair should be considered for individuals at a high risk of rupture who are fit for surgery. Open repair, increased age, and a high comorbidity score are associated with higher mortality.