Endoscopic Anatomy And Clinical Research, To Expand The Treatment Of Giant Pituitary Adenoma Transsphenoidal

Pituitary adenoma is a benign epithelial neoplasm which origin from anterior and posterior pituitary lobe. The incidence of pituitary adenoma is one of million. The pituitary adenoma is classified by tumor size into micro-adenoma, macro-adenoma and gigantic or large adenoma. Gigantic pituitary adenoma with special biological character is an intensive and difficult lesion.The treatment methods of pituitary adenoma include surgical operation, radiotherapy and chemotherapy. However, the gigantic adenoma has closely relationship with circumference anatomy and cannot be treated by radiotherapy firstly because radioactivity edema can lead to anopsia and coma. Although the chemotherapy can reduce hormone secretion shortly, but not control the growth long term. The radiotherapy and chemotherapy are auxiliary therapy for gigantic adenoma. The majority treatment method of gigantic adenoma is surgical operation which can be classified into transcranial and transsphenoidal approach by surgical route. The selection of surgical approach was a variation process. In 1907, Schloffer firstly cured a pituitary adenoma via transnasal transethmoidal transsphenoidal approach. Operation instruments and illumination of operative field and high mortality because of high incidence of postoperative cerebrospinal rhinorrhea limited the advance of transsphenoidal approach. In1889 Horsley cured a pituitary adenoma by transfrontal approach. After then transcranial surgery was a chief treatment method until 70th of 20 century. With the application of operative microscope and new operative instruments and antibiotics, the transsphenoidal approach has been became a chief method. At present, 19 percent of patients with primary brain tumors and 95 percent with pituitary adenoma can be cured by transsphenoidal surgery.The operative trauma of transsphenoidal surgery is more minimally invasive compare with transcranial surgery. The mini-invasive surgery has been used in neurosurgery, otolaryngology, orthopedics, and general surgery. In 1992, Jankowski made use of endoscopies in transsphenoidal surgery for lesion of sellar. At present, the endoscopes transsphenoidal surgery has been used in treatment of pituitary adenoma. The indication of transsphenoidal surgery includes micro-adenoma and some macro-adenoma, but the gigantic adenoma is contraindication of transsphenoidal surgery. Recently more and more people explore new treatment methods of pituitary adenoma via transsphenoidal surgery. The most advance is the extended approach which have been used for tumor originate from stalk of pituitary. The extended transsphenoidal approach can expend the traditional indication of transsphenoidal approach and cure gigantic adenoma instead of transcranial approach.Objectives: The purpose of the article is to explore the possibility of endoscopic extended transsphenoidal approach for gigantic pituitary adenoma and make the technique into a method of gigantic adenoma. In the research the author study the endoscopic anatomy of sellar and parasellar region systemic.Methods: The endoscopic anatomy of sellar and parasellar region was studied via trans-super orbital keyhole approach and extended transsphenoidal approach. Some anatomic parameters were measured meanwhile. The clinical data of 13 cases with gigantic pituitary adenoma cured by endoscopic extended transsphenoidal approach was studied retrospectively.Results: The anatomic structure of sellar and parasellar region such as pituitary gland, stalk of pituitary, chiasm, optic nerve, internal carotid artery, basilar artery can be displayed via trans-super orbital approach. In extended transsphenoidal approach, the process of bone can classify the sphenoidal sinus into a medial compartment, two paramedical and lateral compartments. The pituitary gland can be shown by resection of bone and dura of sellar floor. The cavernous sinus and contents of cavernous sinus such as internal carotid artery and its branches and oculomotor nerve and trochlear nerve and abducent nerve can be visualized laterally. The chiasm and optic nerve and stalk of pituitary can be displayed superiorly.The 13 cases with gigantic pituitary adenoma including 7 males and 6 females was cured by endoscopic extended transsphenoidal approach. All patients had headache, 5 cases with acromegaly, 2 cases with amenorrhea and lactation, 6 cases with subtotal hairs exfoliation and sexual hypofunction, 5 cases with hypopituitarism, 11 cases with visual deterioration, 1 cases with ocular movement disability. 4 cases with hypertension and 2 cases with diabetes mellitus who all were acromegly. The pituitary hormone of all patients was measured by radio-immunity pre- and post-operation. The pituitary hormone were list preoperative: PRL: 23.0-1100.0(X ± SD79.9±49.7)ug/L; GH:50.0-210.0 (X+SD78.1+25.4) ug/L; FSH: 0.2-26.0 (X±SD9.1±8.2)Iu/L; LH: 0.6-31.6(X±SD8.3±7.8)Iu/L; ACTH: 9.6-39.6(X±SD15.4±7.4)Iu/L; TSH: 0.2-3.4 (X±SD1.3±0.8)mu/L. All patients except 1 case only examined by CT underwent CT and MRI examination. The CT or MRI shown the size of tumor were 5 X 35 X 35mm3~30 X 30 X 25mm3 (Average36 X 32 X 30mm3). The tumor invaded into sphenoid sinus in 7 cases. The signal of MRI of all patients excepted one displayed high signal in T2 weight. 3 cases with identical signal in Tl weight and 10 cases with low signal in Tl weight. The pituitary adenoma include 6 cases with chromophobe adenoma, 3 cases with oxyphilic adenoma, 3cases with mixed type adenoma and 1 cases with basophilic adenoma classified by HE staining; and 6 cases with non-function adenoma and 7 cases function adenoma by function of pituitary adenoma; and 2 cases with prolactin-secretion adenoma and somatotropin-secretion adenoma by immunity examinations.The 6 patients cured by transcollum transnasal septum transsphenoidal sinus approach and 7 patients by transnasal transsphenoidal approach. 10 patients had total resection tumor in endoscopes and others subtotal resection. The headache of all patients relieved or disappears and visual acuity of 3 cases had improved obviously. The psychiatric symptom of 1 case preoperative disappears in one week postoperative. The amenorrhea and lactation of 2 cases had improved obviously and sexually function recover only 1 of 4 patients with sexually hypofunction. The serum PRL decreased into normal level in 5 of 9 patients with hyperprolactine postoperative and not decreased into normal level in 4 of 9 cases recovered after treatment by Bromocriptine. The serum GH decreased into normal level postoperative in 1 of 3 cases with acromegly. Postoperative 6 cases occurred transient diabetes insipidus, 2 cases transient cerebrospinal rhinorrhoea cured by conservative therapy. 1 patients recover by treatment of drug occurred acute hypopituitarism postoperative. There were not death or intracranial infection in all cases and not nasal complication such as nasal adherence etc. All the patients with subtotal resection tumor received radiotherapy postoperative including external radiotherapy and stereotaxic radiosurgery. The tumor of all patient followed 2-29 months (Average 12m) have been not relapse or regrowth by radiology examinations.Conclusions: Sellar and parasellar region is a complicated anatomic structure. The pituitary gland locates in pituitary fossa of sellar turcica. There are cavernous and its contents including internal carotid artery and its branches and some cranial nerve through cavernous sinus laterally and chiasm, optic nerve, stalk of pituitary superiorly. The extended transsphenoidal approach canreveals the anatomic structure as a center of pituitary fossa and can be used for treatment of gigantic pituitary tumor. All patients should be evaluated by detailed radiology including MRI and CT.The surgeon should be familiarity with the sellar and parasellar anatomy and skilled with transsphenoidal surgery and take important in dealing with water and electrolure balance in during operation.