Role of Endovascular Approach as Diagnostic Technique and First-Line Therapy for the Patients with Micro-Arteriovenous Malformations: A Case Report and Literature Review.

Objective: We describe a rare case report of micro-arteriovenous malformation (micro-AVM) treated by the endovascular approach in addition with literature review.

Case Presentation: A 12-year-old boy presenting with a spontaneous intracerebral hematoma in the left occipital lobe underwent conventional diagnostic workups. The results of initial catheter angiography were considered to be equivocal as the AVM. Superselective angiography (SA) demonstrated a micro or small AVM (single feeder and single drainer type) with an aneurysmal dilatation. Immediate transarterial embolization (TAE) might fail to occlude the whole of nidus area completely, and subsequently, we switched to the surgical exploration of AVM lesion. Intraoperative findings demonstrated that the whole of AVM lesion had already been occluded completely, indicating the complete occlusion by TAE only. Pathological findings of the surgical specimen showed an aneurysmal dilatation was a venous aneurysm with vulnerable vascular wall structure, which was certainly the source of bleeding. Based on the above results, the retrospective revaluation of superselective angiogram permitted us to understand that the nidus of AVM was micro nidus type and TAE had resulted in the complete nidus occlusion.

Conclusion: SA is the most useful diagnostic modality to clarify the angioarchitecture of micro-AVM and AVM-related aneurysms. If SA is successfully performed and relatively safe TAE is expected to be possible, the subsequent attempt to do curative embolization as a first-line treatment may be worthy of consideration. However, the surgical procedure should be fully reserved for the possible incomplete obliteration and hemorrhagic complications.