[Preservation of pituitary stalk in the microsurgery of giant pituitary adenoma and its significance].

Objective: To investigate and elucidate how to preserve the pituitary stalk in the microsurgery of giant pituitary adenoma (GPA) and its clinical significance.

Methods: 45 GPA patients, 23 males and 22 female; aged 40.8, including 12 cases of invasive pituitary adenoma (IPA) underwent craniotomy based on the respective preoperative neuroradiological imaging characteristics. The anatomical relationship between the pituitary stalk and tumor was recorded. The methods to protect the pituitary stalk were summarized.

Results: Total tumor excision was achieved in 25 patients (55.5%), near-total resection was done in 12 (26.7%), and subtotal resection in 8 (17.8%). During the surgical proceeding, the pituitary stalk was distinguished from the tumor and preserved well in all 33 cases with non-invasive giant pituitary adenoma. On the contrary, in the 12 cases of invasive giant pituitary adenoma (IPA) the pituitary stalk was visualized in only 7 cases. In the patients with visualized pituitary stalks 4 pituitary stalks were not identified very well. In most cases (91%) the pituitary stalks were located laterally (on the left or right side) or supero-posterior to the tumor, only a few were located anteriorly. In all 12 IPA patients 2 cases of postoperative hemorrhage occurred associated with remnant tumor and immediate hematoma evacuation was performed, however, one patient died due to hypothalamus injury.

Conclusion: Pituitary stalk has various anatomical relationships to the entity of GPA; most are located lateral or supero-posterior to the tumor. However, the relationship between the stalk and tumor is not clear in IPA. Identifying and preserving the pituitary stalk well during surgical manipulation will be beneficial to get an excellent outcome.