[Visual acuity outcome and recurrence in large or huge pituitary adenomas operated with transcranial approach: comparison between frontotemporal and interhemispheric approaches].

Pituitary macroadenomas which required transcranial removal were reviewed concerning visual acuity outcome as well as recurrence. We encountered 173 pituitary adenomas of which 27 (15.6%) were removed transcranially during the past 13 years. Eight cases were excluded due to inadequate information and improper utilization. Thus, a total of nineteen cases were reviewed in which the frontotemporal (FT) approach was utilized for seven cases and the interhemispheric (IH) approach for 12 cases. The mean size and volume of the tumors in the FT group were 3.0 x 3.7 x 3.1 cm and 18.2 cm3. The main reason for utilizing this approach was the fact that the tumors extended laterally involving the unilateral cavernous sinus or that unilateral preoperative visual acuity was obstructed. The visual acuity outcome was as follows: In six cases showing useful visual acuity on both sides before surgery, no apparent aggravation on either side was found in four cases, while in two cases there was complete obstruction on the operative side. The remaining case showed aggravation on both sides, though the approach side was decided upon because of the obstructed vision on that side. The mean size and volume of the tumors in the IH group were 4.6 x 4.8 x 4.9 cm and 71.1 cm3. This approach was used due to the extreme suprasellar extension because of the large size of the tumors. Although the tumors were relatively large and the visual acuity was assessed as fair prior to surgery, visual acuity showed no significant deterioration after the operation and was found to be satisfactory in 11 out of 12 cases. The complications in the FT group were oculomotor palsy in 3 cases, hemorrhage in one case, and frontal infarction in one case. On the other hand, three cases suffered hemorrhage in the tumor cavity of the IH group, though none needed surgical evacuation. Most of the cases in the IH group showed pituitary hypofunction following the surgical removal of the tumors as compared to the cases in the FT group. Recurrence had occurred, in some cases, several years after the operation. Furthermore, some of the tumors are still growing larger following only partial or subtotal removal. The prime aim of the treatment for huge pituitary adenomas which require the transcranial removal is to retain as much visual acuity as possible. In conclusion, the IH approach has been shown to be preferable in this situation. The FT approach was found to be more dangerous in terms of visual outcome than had been expected, even if the tumors were not particularly large.