Endovascular Treatment of Abdominal Aortic Aneurysm and Impact of Annual Caseload in the Quality Registry of the German Society for Vascular Surgery and Vascular Medicine (DGG).

Objective: While the impact of annual caseload on short term outcomes after abdominal aortic aneurysm (AAA) repair remains under debate, current data from the most decentralised healthcare system in Europe may offer valuable insights into an area that has changed considerably due to the widespread use of endovascular aortic aneurysm repair (EVAR).

Methods: This was a retrospective observational study of multicentre quality registry data from Germany on EVAR for intact and ruptured AAA between January 2017 and December 2023. The impact of annual caseload and risk factors on in hospital death, complication rates, and failure to rescue after intact AAA repair was determined using multivariable logistic regression models.

Results: A total of 19 641 individuals (n = 2 576 females [13.1%]; median age 74 years, interquartile range [IQR] 68, 80) who underwent EVAR for intact (n = 18 763) or ruptured (n = 878) AAA were included from 194 centres. Among these, 44.3% of males were selected for treatment with a maximum diameter < 55 mm (31.8% of females < 50 mm). After a median length of hospital stay of six days (IQR 5, 8) and 10 days (IQR 6, 17) for intact and ruptured cases, 1.0% and 19.7% died, respectively. The rate of any post-interventional complication was 8.2% and 31.4%, respectively. An endoleak was apparent on the completion angiogram in 17.6% of intact cases (14.5% type II) and 18.2% of ruptured cases (11.0% type II). The median annual EVAR caseload per centre was 34.7 (IQR 22.1, 58.4), and 25.1% of patients were treated at centres above the 75th percentile. An American Society of Anesthesiologists (ASA) score ≥ 4, juxtarenal aneurysm extent, severe heart failure, female sex, larger aneurysm diameter, older age, and history of cancer, chronic obstructive pulmonary disease, and stroke were associated with in hospital death after intact AAA repair, but annual caseload and severe chronic kidney failure were not. Sensitivity analyses including different outcomes were confirmative, except for a statistically significant impact of annual caseload on the composite endpoint of any post-interventional complication (p = .008).

Conclusion: This large registry analysis was unable to confirm an impact of caseload on short term results after EVAR for intact AAA. Future studies should address long term outcomes after EVAR as well as the underlying reasons for the considerably large proportion of small diameter AAA treatment.