gms | German Medical Science

Objective: Intracranial infectious aneurysms (IIAs) are a rare clinical entity without a definitive treatment guideline. In this study we evaluate the treatment options of these lesions based on our own clinical experience and review the current knowledge of therapy as portrayed in the literature.

Method: We conducted a single center retrospective analysis of all patients with an IIA and performed a systematic review of the literature using the MEDLINE database. We undertook a comprehensive literature search using the OVID gateway of the MEDLINE database (1950-Oct 2015) using the following keywords (in combination): "infectious", "mycotic", "cerebral aneurysm", "intracranial aneurysm". 1721 potentially relevant abstracts were identified and 63 studies were selected for full review. The studies were analyzed regarding ruptured vs. unruptured aneurysms, aneurysm localization and treatment, as well as clinical outcome.

Results: Our institutional series consisted of 6 patients (median age: 57 (32-76) years) treated between 2011 and 2015. All patients presented with ruptured IIAs and localized at the middle cerebral artery (MCA, 5 patients) and anterior cerebral artery (ACA, 1 patient). Five patients were treated by clipping and resecting the aneurysm, one patient underwent coiling. All patients received antibiotic therapy. Mortality was 0%. We further identified 804 patients (median age: 35.5 (0-81) years) in 63 studies. Ruptured aneurysms were reported in 631 patients. Localizations of the aneurysms were mentioned in 55 studies. The most frequent locations of the aneurysms were: MCA (63.5%), posterior cerebral artery (PCA, 14.0%), ACA (9.0%) and others (13.5%). Treatment for IIAs was described in 62 studies: conservative antibiotic treatment (56.1%), a combination of antibiotics and surgical (20.9%) or antibiotics and endovascular treatment (23.0%). Outcome was mentioned in 82.4% of the patients with a mortality rate of 16.8%. An evaluation of treatment outcome was limited due to the heterogeneity of patients in the published case series.

Conclusions: Antibiotic therapy of patients with IIA is mandatory. However, due to the complexity of the disease and its accompanying comorbidities a general treatment algorithm could not be defined. Analogous to non-mycotic aneurysms, further treatment decisions require an interdisciplinary scenario involving neurosurgeons, interventionalists and – additionally- infectious disease specialists.