J Neurol Surg B
DOI: 10.1055/s-0039-1692474
Original Article
Georg Thieme Verlag KG Stuttgart · New York

A Classification for the Anterior Inferior Cerebellar Artery—Subarcuate Artery Complex Based on the Embryological Development

1  Department of Neurosurgery, Italian Hospital of Buenos Aires, Buenos Aires, Argentina
,
Pedro Plou
1  Department of Neurosurgery, Italian Hospital of Buenos Aires, Buenos Aires, Argentina
,
Álvaro Campero
2  Department of Neurosurgery, Padilla Hospital, Tucumán, Argentina
,
Pablo Ajler
1  Department of Neurosurgery, Italian Hospital of Buenos Aires, Buenos Aires, Argentina
› Institutsangaben
Weitere Informationen

Publikationsverlauf

14. Februar 2019

11. Mai 2019

Publikationsdatum:
21. Juni 2019 (online)

Abstract

Objective To hierarchize the anterior inferior cerebellar artery (AICA)–subarcuate artery (SAA) complex's variations in the surgical field.

Background The AICA's “subarcuate loop” (SL) presents multiple variations, closely related to the SAA. AICA-SAA complex's variations may represent major issues in cerebellopontine angle (CPA) surgery. As the spectrum of configurations is originated during the development, a systematized classification was proposed based on the interaction between the petrosal bone and the AICA in the embryonic period.

Methods The variations were defined as follow: Grade 0: free, purely cisternal AICA, unidentifiable or absent SAA; Grade 1: purely cisternal AICA, loose SL, SAA > 3 mm; Grade 2: AICA near the subarcuate fossa, pronounced SL, SAA <3 mm; Grade 3: “duralized” AICA, unidentifiable SAA, or included in the petromastoid canal (PMC); and Grade 4: intraosseous AICA, unidentifiable SAA, or included in the PMC. The classification was applied to a series of patients assessed by magnetic resonance constructive interference in steady state sequence. Surgical examples were also provided.

Results Eighty-four patients were evaluated, including 161 CPA. The proportions found in the gradation remained within the range of previous publications (Grade 0: 42.2%; Grade 1: 11.2%; Grade 2: 35.4%; Grade 3: 10.6%; and Grade 4: 0.6%). Moreover, the degrees of the classification were related to the complexity of the anatomical relationships and, therefore, to the difficulty of the maneuvers required to overcome them.

Conclusion The proposed AICA-SAA complex classification allowed to distinguish and objectify pre- and intraoperatively the spectrum of variations, to thoroughly plan the required actions and instrumentation.