Anterior contralateral interhemispheric transcallosal transforaminal approach for resection of large medial thalamic cavernous malformation: case report and 2D operative video

Background: Thalamic cavernous malformation (CM) are relatively rare lesions. Results came mainly from case report or small case series which were collected in specialized centers. Due to high risk of postoperative neurological deficits many of these are considered inoperable. However, an adequate approach selection can minimize the risk while reaching a satisfying extent of resection. An attempt to standardize the best surgical corridor to reach these deep lesions has been proposed by dividing the thalamus into 6 different regions. Case Description: A case of bleeding CM of the medial region of the thalamus and its surgical management has been reported. A 35-year-old woman required urgent medical attention for progressive and unresponsive headache in the context of intracranial hypertension due to cerebrospinal fluid (CSF) obstruction at the level of the aqueduct. Imaging work-up showed a bleeding lesion of the right thalamus. In order to manage the hydrocephalus, an endoscopic third ventriculostomy (ETV) was performed without complications. After discharge, a new brain magnetic resonance imaging (MRI), one month later, showed increasing dimension of the lesion and signs of rebleeding. A contralateral interhemispheric transcallosal transforaminal approach was selected to approach the lesion. The subsequent course was uneventful with improvement of the left-hand tremor. The postoperative brain MRI confirmed the complete removal of the lesion and no sign of recurrence was shown at 3-and 12-month follow-up imaging. Conclusions: Surgery of thalamic cavernomas is extremely complex. While there is a body of literature examining the optimal surgical corridors for lesions in different thalamic locations, the selection of the surgical approach must be tailored to the specific anatomy of each case, particularly for lesions with significant bulk that could alter regional anatomy.