Pontine cavernous malformation: microsurgery evading the floor of the fourth ventricle

Area of Science:

• Neurosurgery
• Cerebrovascular Surgery
• Skull Base Surgery

Background:

• Pontine cavernous malformations pose surgical challenges due to their proximity to vital neural structures.
• The floor of the fourth ventricle (f4V) is a common surgical corridor, but risks injury to adjacent cranial nerve nuclei.
• Preservation of the abducens and facial nerve nuclei is paramount during pontine lesion resection.

Purpose of the Study:

• To demonstrate an alternative surgical approach for left pontine cavernous malformation resection.
• To highlight the preservation of cranial nerve function using a lateral supracerebellar approach.
• To discuss the implications for the "safe entry zone" philosophy in neurosurgery.

Main Methods:

• A lateral supracerebellar infratentorial approach was utilized for resection.
• The surgical corridor involved dissection through the middle cerebellar peduncle.
• Intraoperative visualization and postoperative MRI were used to confirm resection and anatomical integrity.

Main Results:

• Complete resection of the left pontine cavernous malformation was achieved.
• The patient remained neurologically intact at 3-month follow-up.
• Postoperative MRI showed preserved pontine tissue, suggesting minimal disruption of the f4V.

Conclusions:

• The lateral supracerebellar approach is a safe and effective alternative for pontine cavernous malformations abutting the f4V.
• This approach facilitates preservation of the abducens and facial nerve nuclei.
• The study questions the universal applicability of the "safe entry zone" concept for pontine lesions.