Modified Retromastoid Approach and Clipping of “High-Riding“ VA-PICA Junction Aneurysm: An Operative Video

Background and Introduction: Clipping an aneurysm on an elongated and tented V4 segment near the origin of the posterior inferior cerebellar artery (high-riding VA-PICA junction aneurysm) can be challenging. Objective: We demonstrate the microsurgical clipping technique of such an aneurysm using a modified retromastoid approach (MRMA) and glossopharyngeal-cochlear triangle (GCT). Surgical Technique: A 50-year-old female with a ruptured high-riding left VA-PICA junction aneurysm underwent an MRMA. Using segmental vessel isolation with proximal and distal temporary clips, this aneurysm was occluded through the GCT by applying a tandem clipping technique while preserving the PICA. Results: The procedure was uneventful. Apart from transient ataxia, she recovered completely and maintains a good status at follow-up. Conclusion: In high-riding VA-PICA junction aneurysms, a conventional far lateral approach may create awkward viewing and working angles. An MRMA with a horizontal trajectory through the GCT may be a more appropriate strategy.