Microsurgical Techniques of Removal of Neoplasms of Sellar Region via Pterional Approach Through Lamina Terminalis

Objective To discuss the techniques and results of opening of the lamina terminalis, which is used for the exposure and total removal of the tumors of the sellar region,such as craniopharyngiomasjarge pituitary adenomas,germ cell tumors and meningiomas through the pterional approach. Methods Forty-four of 347 patients with tumors of the sellar region, who were treated in our department from 1994 to 1998, underwent opening of the lamina terminalis to remove the tumors. Prefixed optic chiasma and the tumors invading into the anterior portion of the third ventricle, which could be known from the preoperative MRI, were the indications of the opening the lamina terminalis. Careful dissection of the sylvian cistern, carotid cistern and chiasmatic cistern and divorce of the arachnoid connection were necessary for the exposure of the lamina terminalis. It was important to make a incision parallel to the ipsilateral optic tract on the lamina terminalis and to distinguish and protect the optic chiasm and the contralateral optic tract in order to prevent the postoperative deficit or even loss of the visual acuity and field. The intratumoral removal, traction and striping of the tumors via the space 1 and space 2 were the effective methods of the total removal and preventing the damage to the hypothalamus or the thalamus. Results Opening of lamina terminalis and/or space 1 and space 2 was used for the removal of the tumors in the sellar region. The rate of total removal of the sellar region tumors was 84% (37/44), and the rates of the total removal of the craniopharyngiomas and pituitary adenomas was 94% (29/31) and 89% (8/9) respectively. The postoperation mortality was 14.6%, resulting from grand mal and persistent epileptic state which appeared frequently in the reoperative patients with recurrent tumors. Conclusions There are the hypothalamus and other important nuclei near the lamina terminalis, but the surgical techniques presented here, by which the tumors in the sellar region can be totally removed, can prevent these important structures from damage.