Transcallosal Approach for Intraventricular Tumors

Preoperative Considerations

• The transcallosal approach allows midline exposure of the anterior two-thirds of the third ventricle.

• Preoperatively, in addition to standard MR imaging, venography is often helpful to assess the pattern of cortical venous drainage in order to help determine the side of the craniotomy.

• When venous drainage permits and when the pathology is appropriate, an approach on the non-dominant side is preferred.

• Preoperative neuropsychological evaluation is recommended in those patients with preoperative symptoms of cognitive impairment (e.g. memory deficits), owing to potential risk of injury to the fornices during the approach.

Indications

• Lesions of the anterior portion of the lateral ventricle, thalamus/basal ganglia and third ventricle.

Contraindications

• Contraindicated in patients with “crossed dominance” where the hemisphere controlling the dominant hand is contralateral to the hemisphere responsible for speech — such patients are at risk for a “disconnection syndrome” and patients may develop writing and speech deficits postoperatively (particularly with larger or posteriorly positioned callosal incisions).

• This approach provides limited access to the anterior part of the frontal horn, posterior trigone or temporal horn. The transcortical approach is a safe alternative for those lesions ( Figure 14.1 ).

  

Surgical Procedure