Aneurysms of the Proximal Segment of the Anterior Cerebral Artery: A New Classification System with Corresponding Therapeutic Options

• Published in: World neurosurgery Vol. 104; pp. 291 - 302
• Main Authors: Ding, Xinmin, MD, PhD, Nisson, Peyton Lubbock, BS, James, Whitney S., MD, MHS, Lawton, Michael T., MD, Ren, Shaohua, MD, Jia, Lu, MD, Ji, Honging, MD
• Format: Journal Article
• Language: English
• Published: United States Elsevier Inc 01.08.2017
• Subjects: Aneurysm; Anterior cerebral artery; Anterior Cerebral Artery - surgery; Classification; Combined Modality Therapy - standards; Embolization, Therapeutic - standards; Evidence-Based Medicine; Female; Humans; Intracranial Aneurysm - classification; Intracranial Aneurysm - diagnosis; Intracranial Aneurysm - therapy; Male; Middle Aged; Neurosurgery; Neurosurgical Procedures - standards; Practice Guidelines as Topic; Precommunicating artery aneurysm; Pregnancy; Proximal segment of anterior cerebral artery; Treatment; Treatment Outcome; United States; Vascular Surgical Procedures - standards; aneurysm; treatment; moderate disability; pre-communicating artery aneurysm; digital subtraction angiography; Glasgow Outcome Scale; GOS; proximal segment of anterior cerebral artery; GR; classification; A1; SD; DSA; proximal anterior cerebral artery; severe disability; MD; good recovery; anterior cerebral artery; ACA; CT; Treatment; Aneurysm; Classification; Precommunicating artery aneurysm; Proximal segment of anterior cerebral artery; MCA; Anterior cerebral artery; ACOM
• ISSN: 1878-8750; 1878-8769
• DOI: 10.1016/j.wneu.2017.04.106

Abstract Objective This study aims to establish a new classification system for proximal anterior cerebral artery (A1) aneurysms and to offer treatment strategies, based on the lessons learned by studying the case reports of 41 patients with A1 aneurysms. Methods 2,332 consecutive patients with intracranial aneurysms were treated at a single medical center between June 2005 and May 2015. Forty-one patients with 42 A1 aneurysms were treated by surgical clipping or endovascular coiling. Clinical data, radiographic results, treatments, and patient outcomes were later collected and analyzed. Results 1.76% (41/2332) of intracranial aneurysm patients had a total of 42 A1 aneurysms. Twenty-six of these (62%) were proximal A1 segment aneurysms, nine (21%) distal A1 segment aneurysms, and seven (17%) fusiform A1 aneurysms. A1 aneurysms can be classified into three main types: Type IA and IB originate from the posterior wall of the proximal A1 segment. Type IA project posterior-inferiorly, while Type IB project posterior-superiorly. Type IIA originate from the distal trunk of the A1 artery. Type IIB originate from an angle of an abnormal cortical branch or a ring of an A1 arterial fenestration. Type III are fusiform or dissecting aneurysms located anywhere along the A1 segment. After studying the range of treatments and outcomes, when treating these complex morphologies, we recommend clipping Type I and II A1 aneurysms and embolizing Type III A1 aneurysms. Conclusion A1 artery aneurysms are a rare type of aneurysm with unique characteristics. The classification system proposed here accurately summarizes these characteristics to better guide treatment strategies.