Alex De Vilalta1, Ioannis Kournoutas2, Pablo López Ojeda3, Andreu Gabarrós Canals3, Vera Vigo2, Caleb W Rutledge4, Ricky Chae2, Adib A Abla5, Roberto Rodriguez Rubio6. 1. Skull Base and Cerebrovascular Laboratory, University of California, San Francisco, California, USA; Department of Neurosurgery, Hospital Universitari de Bellvitge, Barcelona, Spain. 2. Skull Base and Cerebrovascular Laboratory, University of California, San Francisco, California, USA. 3. Department of Neurosurgery, Hospital Universitari de Bellvitge, Barcelona, Spain. 4. Department of Neurological Surgery, University of California, San Francisco, California, USA. 5. Department of Neurological Surgery, University of California, San Francisco, California, USA; Skull Base and Cerebrovascular Laboratory, University of California, San Francisco, California, USA. 6. Department of Neurological Surgery, University of California, San Francisco, California, USA; Skull Base and Cerebrovascular Laboratory, University of California, San Francisco, California, USA; Department of Otolaryngology-Head and Neck Surgery, University of California, San Francisco, California, USA. Electronic address: luis.rodriguezrubio@ucsf.edu.
Abstract
INTRODUCTION: Anterior inferior cerebellar artery (AICA) aneurysms are rare, accounting for 0.2%-1.3% of all intracranial aneurysms. The standard treatment is often endovascular embolization or neck clipping; however, sacrifice of the parent vessel is sometimes necessary. Addition of revascularization procedures is a subject of controversy. The occipital artery (OA) has been used as a donor for bypass, but recently there has been a trend toward intracranial-intracranial approaches. The posterior inferior cerebellar artery (PICA)-AICA side-to-side bypass may serve as a safe alternative. OBJECTIVE: To characterize the PICA-AICA side-to-side bypass and the OA-AICA end-to-side bypass and review the literature relevant to AICA revascularization. METHODS: We performed a far-lateral approach on 12 cadaveric specimens and analyzed the regional anatomy. On this basis, we performed either an OA-AICA or a PICA-AICA bypass and took morphometric measurements relevant to the technique. RESULTS: PICA-AICA bypass was successful in 6/12 specimens. The length of the flocculopeduncular segment was 42.6 ± 15.8 mm in the specimens in which the bypass was feasible and 26.2 ± 7.2 mm in those in which the bypass was not feasible (P = 0.04). Mean distance between AICA and PICA was 5.3 ± 4 mm in the specimens in which side-to-side bypass was feasible and 11.6 ± 4.2 mm in the specimens in which it was not (P = 0.02). OA-AICA end-to-side bypass was feasible in all the specimens (75% in the flocculopeduncular segment; 25% in the cortical segment). CONCLUSIONS: This is the first cadaveric study analyzing the PICA-AICA side-to-side bypass for AICA revascularization. Our analyses provide evidence for the feasibility of this bypass and document the anatomic variations that may indicate its use.
INTRODUCTION:Anterior inferior cerebellar artery (AICA) aneurysms are rare, accounting for 0.2%-1.3% of all intracranial aneurysms. The standard treatment is often endovascular embolization or neck clipping; however, sacrifice of the parent vessel is sometimes necessary. Addition of revascularization procedures is a subject of controversy. The occipital artery (OA) has been used as a donor for bypass, but recently there has been a trend toward intracranial-intracranial approaches. The posterior inferior cerebellar artery (PICA)-AICA side-to-side bypass may serve as a safe alternative. OBJECTIVE: To characterize the PICA-AICA side-to-side bypass and the OA-AICA end-to-side bypass and review the literature relevant to AICA revascularization. METHODS: We performed a far-lateral approach on 12 cadaveric specimens and analyzed the regional anatomy. On this basis, we performed either an OA-AICA or a PICA-AICA bypass and took morphometric measurements relevant to the technique. RESULTS: PICA-AICA bypass was successful in 6/12 specimens. The length of the flocculopeduncular segment was 42.6 ± 15.8 mm in the specimens in which the bypass was feasible and 26.2 ± 7.2 mm in those in which the bypass was not feasible (P = 0.04). Mean distance between AICA and PICA was 5.3 ± 4 mm in the specimens in which side-to-side bypass was feasible and 11.6 ± 4.2 mm in the specimens in which it was not (P = 0.02). OA-AICA end-to-side bypass was feasible in all the specimens (75% in the flocculopeduncular segment; 25% in the cortical segment). CONCLUSIONS: This is the first cadaveric study analyzing the PICA-AICA side-to-side bypass for AICA revascularization. Our analyses provide evidence for the feasibility of this bypass and document the anatomic variations that may indicate its use.