Reangiography after perimesencephalic subarachnoid hemorrhage

This study aimed to determine the value of digital subtraction angiography (DSA) for the detection of causative vascular lesions in patients with perimesencephalic subarachnoid hemorrhage (SAH) after initially negative noninvasive and invasive neurovascular imaging, such as computed tomography angiography (CTA), DSA and magnetic resonance angiography (MRA). We analyzed the value of repeated DSA for the detection of causative vascular lesions in 750 patients presenting to our institution with SAH and including 30 with a purely perimesencephalic pattern of subarachnoidal hemorrhage and initially negative noninvasive and invasive neurovascular imaging over a 10-year period. Repeated DSA demonstrated a causative vascular lesion in 1 patient (3.3 %) but no causative vascular lesions were detected in the other patients. Repeated DSA can be used to detect a source of hemorrhage after initially negative imaging diagnostics in some rare cases. Such a finding has a therapeutic and prognostic impact especially for aneurysms in the posterior circulation which bear a higher risk of renewed hemorrhaging. Therefore, we believe that repeated DSA should be recommended in patients with perimesencephalic SAH even under consideration of the risk of complications caused by a second invasive DSA.