Cerebral aneurysms: Germany-wide real-world outcome data of endovascular or neurosurgical treatment from 2007 to 2019

Background: Evidence on clinical outcome after endovascular treatment (EVT) vs neurosurgical clipping of intracranial aneurysms (IAs) is based on one randomized and one pseudo-randomized trial for ruptured aneurysms. Herein, we analyze nationwide real-world hospital outcomes after EVT vs clipping of ruptured and unruptured IAs.

Methods: This cohort study analyzed all EVT and clipping procedures for IAs in Germany between 2007 and 2019. The data basis was the billing-data of all German hospitals from the German Federal Statistical Office. EVT and clipping interventions, comorbidities, and in-hospital outcomes were identified using International Classification of Diseases (ICD) and Operation and Procedure (OPS) codes. Discharge type was used as a surrogate marker for functional independence. Poor clinical outcome at discharge was additionally defined by the dichotomous US National Inpatient Sample-Subarachnoid hemorrhage Outcome Measure score (NIH-SOM). Secondary outcomes included length of hospital stay, prolonged mechanical ventilation (>48 hour), and hospital reimbursement.

Results: We analyzed 90 039 procedures (62.6% EVT, 35.52% clipping, 1.8% combined) for the treatment of IAs. After adjustment in-hospital mortality was equal after EVT compared with clipping, in ruptured IAs (adjusted OR (aOR) 0.98, p=0.707) and unruptured IAs (aOR 0.92, p=0.482). Functional independence was more likely after EVT for ruptured (aOR 0.81, p<0.001) and unruptured IAs (aOR 0.4, p<0.001). Poor clinical outcome was more likely after clipping for ruptured (aOR 0.67, p<0.001) and unruptured IAs (aOR 0.56, p<0.001).

Conclusions: In German clinical practice, we observed higher rates of functional independence and lower rates of poor outcomes at discharge with equal mortality for EVT.