Two cases of ventral midbrain cavernous malformations successfully removed through orbitozygomatic interpeduncular approach

• Surgical resection of ventral midbrain cavernous malformations (VMCMs) is difficult.
• Orbitozygomatic interpeduncular approach (OZIA) is useful for ventral midbrain lesions.
• Contralateral orbitozygomatic interpeduncular approach may be effective depending on the Contralateral OZIA may be effective depending on the location and range of VMCMs.

Ventral midbrain cavernous malformations are rare, and annual bleeding rate is higher than supratentorial lesions. Rebleeding rate is also high if surgical resection is incomplete. The ventral midbrain is deeply located and surrounded by many perforators, which make the approach to this region difficult.We experienced two cases of ventral midbrain cavernous malformations successfully removed via orbitozygomatic interpeduncular approach. In these cases, most parts of the lesions exist behind the cerebral peduncle extending interpeduncular fossa. In the first case involving a 15-year-old girl, we removed the lesion completely through an ipsilateral orbitozygomatic interpeduncular approach with minimum sacrifice of the right cerebral peduncle. However, in the second case involving a 43-year-old man, the same approach did not reach the lesion behind the ipsilateral cerebral peduncle. At the second operation, a contralateral orbitozygomatic interpeduncular approach was used to remove the residual lesion completely.Ipsilateral and contralateral orbitozygomatic interpeduncular approaches with minimum destruction of the cerebral peduncle are options for the lesions which exist in the interpeduncular fossa and behind the cerebral peduncle.