Non-aneurysmal subarachnoid hemorrhage: When is a second angiography indicated?

Area of Science:

• Neurology
• Radiology
• Neurosurgery

Background:

• Subarachnoid hemorrhage (SAH) diagnosis often involves initial imaging like CT angiography (CTA) and digital subtraction angiography (DSA).
• Repeat imaging in non-aneurysmal SAH (NASAH) is controversial, necessitating further investigation into diagnostic workup needs.
• Classifying NASAH into perimesencephalic (PMSAH) and non-perimesencephalic (nPMSAH) patterns may guide management.

Purpose of the Study:

• To analyze the diagnostic yield of repeat imaging in patients with NASAH.
• To evaluate the necessity of further diagnostic workup based on hemorrhage patterns.
• To determine optimal follow-up strategies for different NASAH subgroups.

Main Methods:

• Retrospective analysis of spontaneous SAH patients with initially negative CT, CTA, and/or DSA.
• Classification of NASAH into PMSAH and nPMSAH based on admission CT findings.
• Review of radiological data including CT, CTA, DSA, and MRI/MRA, with a focus on repeat DSA outcomes.

Main Results:

• 74 patients met inclusion criteria; 39 (52.7%) had PMSAH and 35 (47.3%) had nPMSAH.
• Initial CTA/DSA revealed no vascular abnormalities in all patients.
• A single patient (1.4%) with nPMSAH was diagnosed with an anterior choroidal artery aneurysm on follow-up DSA.

Conclusions:

• Repeat DSA is likely unnecessary for PMSAH if the initial DSA was adequate and showed no complications.
• Follow-up DSA is mandatory in n সম্ভাবিত SAH to rule out or confirm vascular pathologies and prevent rebleeding.
• Hemorrhage pattern is critical in guiding the need for repeat angiography in NASAH patients.