Interhemispheric approach through the lamina terminalis to tumors of the anterior part of the third ventricle.

Operative approaches to tumors of the third ventricle, mainly the bifrontal approach through the lamina terminalis, are discussed. The latter approach has several advantages. First, the main arteries can be exposed and the operative field is sufficiently wide to render the operative procedure safe. Second, cortical incision or excision is unnecessary. By cutting the lamina terminalis, which is usually thin and expanded as a result of hydrocephalus, even a large tumor can be removed. In addition, lethal complications are avoided, because this approach has less possibility of damage to the lateral wall of the third ventricle. Seventeen cases of tumor in the third ventricle underwent operation via this approach. The operative technique for the bifrontal approach through the lamina terminalis and three representative cases are reported. This approach can be applied not only to tumors, but to arteriovenous malformations or giant aneurysms adjacent to the third ventricle.