Background: Cranioplasty is more than cosmetic repair for cranial defects; it is vital for patient rehabilitation after neurological injury. Despite its benefits, cranioplasty is associated with significant complications and requires careful planning. This report details the first reported case of subarachnoid hemorrhage (SAH) caused by failure and migration of titanium mesh used in suboccipital cranioplasty.

Observations: A 49-year-old male experienced recurrent SAH over 4 years, presenting every 2 years. Three years prior, the patient underwent suboccipital decompression craniotomy with titanium mesh implantation at another hospital. Imaging revealed mesh fracture with fragments migrating into the cervical spine at C3 and C4-5. The fractured edge of the mesh penetrated the dura and injured the cerebellar surface. A two-stage surgery removed the fractured mesh and migrated fragments successfully.

Lessons: Suboccipital cranioplasty using titanium mesh and involving the posterior margin of the foramen magnum is at risk of mechanical failure. Stress on the implanted titanium mesh from cervical movement can lead to metal fatigue and injury to the brain, nerves, and blood vessels. https://thejns.org/doi/10.3171/CASE24836.

Keywords: case report; cranioplasty; occipital fossa; subarachnoid hemorrhage; titanium mesh.

背景： 颅骨成形术不仅仅是对颅骨缺损的美容修复，它对于神经损伤后的患者康复至关重要。尽管有其益处，但颅骨成形术也与显著的并发症相关，并需要谨慎规划。本报告详细描述了首例因钛网失败并移位而导致蛛网膜下腔出血（SAH）的病例。

观察： 一名49岁的男性患者在四年间经历了反复发作的蛛网膜下腔出血，每次间隔两年。三年前，该患者曾在另一家医院接受枕部减压颅骨切除术并植入钛网。影像学检查显示钛网发生断裂，并且碎片移位至颈椎C3和C4-5水平。钛网破裂边缘穿透硬脑膜并损伤了小脑表面。经两阶段手术成功移除了断裂的钛网及其移位的碎片。

教训： 使用钛网进行枕部颅骨成形术，特别是涉及枕骨大孔后缘的情况下，存在机械故障的风险。颈椎活动对植入的钛网施加的压力可能导致金属疲劳并损伤大脑、神经和血管。

关键词： 病例报告；颅骨成形术；枕窝；蛛网膜下腔出血；钛网。