垂体微腺瘤所致双颞侧视野缺损的探讨

目的探讨垂体微腺瘤与视交叉功能障碍引起的颞侧视野缺损之间的关系,提出了经蝶手术治疗的意义。方法分析了北京协和医院经蝶手术治疗的5例术前有典型颞侧视野缺损的垂体微腺瘤,并结合文献加以讨论。结果这5例患者术前均有典型的颞侧视野缺损,经蝶手术治疗后3例患者的视野缺损恢复正常,2例不同程度改善。结论结合人体视交叉血液供应的解剖学研究,认为高灌注状态的垂体增殖性病变如肿瘤,通过它与视交叉的共同供应血管分枝进行“盗血”,或干扰了视交叉的正常血液供应,使视交叉中部存在的微循环薄弱环节发生供血障碍,而导致未对视交叉形成直接压迫的垂体微腺瘤能够引起颞侧视野缺损。经蝶手术治疗后5例患者的视野缺损均不同程度地改善或恢复正常,这既反证了上述机制的存在,又显示了经蝶手术治疗的积极意义。

Bilateral temporal visual field defect caused by pituitray microadenoma

Objective To discuss the relation between pituitary microadenoma and temporal visual field defect owing to the disturbance in blood supply of the optic chiasma, and to refer to the significance of transsphenoidal operation. Method To analyze the group of five patients with pituitary microadenoma, who had typical temporal visual field defects before operation, and all of whom were treated by transsphenoidal surgical procedure. To discuss the mechanism and surgical treatment involved in this condition by reviewing the literatures. Result All of the five patients had typical temporal visual field defects before operation surgery. After surgery, they obtained relief in different degree or returned to normal in visual field. Conclusion According to the research on vascular architecture of human optic chiasma, pituitary microadenoma may cause temporal visual field defect without directly compressing the optic chiasma. The mechanism is the blood supply of chiasma is compromised by hyperperfusing lesions(eg. tumor)near the sella turcica, while the weak point of microcirculation located at the median portion of chiasma is apt to be disturbed first or "be shunt"and becomes ischemic, causing disorders of the crossing optic nerve fibers in the median portion of chiasma, and the characteristic temporal visual field defects appear. The patients' postoperative relief or recovery in visual field demonstrate the mechanism and the significance of transsphenoidal operation also.