Analysis of Pontine cavernous malformation resection based on 3D microanatomical study.

Area of Science:

• Neurosurgery
• Neuroanatomy

Background:

• Pontine cavernous malformations (PCMs) are a common type of brainstem cavernous malformation (BSCM).
• PCMs present significant surgical risks due to their location within the brainstem.

Purpose of the Study:

• To analyze surgical strategies for PCMs based on anatomical and clinical considerations.
• To delineate safe surgical corridors and entry points for pontine cavernous malformations.

Main Methods:

• Microdissection of 10 Klingler-prepared human brainstem specimens to map nerve fiber tracts.
• Simulation of surgical approaches on 10 additional specimens to define safe exposure ranges.
• Validation of findings in clinical cases.

Main Results:

• Identified specific safe surgical entry zones: trigeminal quadrangular spaces for ventrolateral PCMs and the interpeduncular sulcus (IPS) combined with the trochlear nerve for dorsolateral PCMs.
• Clarified the 3D spatial relationship between the corticospinal tract (CST) and transverse pontine fibers.
• Determined optimal surgical approaches based on PCM location: subtemporal transtentorial for ventral/ventrolateral, retrosigmoid for inferior/extending PCMs, and extreme lateral supracerebellar infratentorial for dorsolateral PCMs.

Conclusions:

• Anatomical landmarks are critical for selecting optimal surgical entry points and minimizing nerve injury in PCMs.
• Standardized preoperative imaging, intraoperative monitoring, and neuronavigation enhance surgical precision and safety.
• Defined surgical corridors improve outcomes for brainstem cavernous malformation resections.