A Primary Observation About Relationship Between Tumors Of Sellar Region And Cycle Of Willis

Objective For the purpose of avoiding blind manipulation intraoperatively and decreaseing the operative risk,we studied the source of blood supply to tumors arising from sellar region,the relationship between the perforating artery of cycle of Willis and the tumors of sellar region,deduce the possibility of blood supply arising from posterior cycle of Willis to the large sellar tumors,to provide the anatomical attestation for clinical practice.Method From May 2000 to December 2001,the data of microoperation in 60 cases with sellar meningiomas,craniopharyngiomas and pituitary adenomas was collected and retrospectively analyzed. The attention was paid to observe the characteristics of perforating artery of cycle of Willis,the source of blood supply to tumor,and their relationship. In the same period 5 cadaveric brain was dissected,and the relative arteries in skull base and the number,course,distribution of their perforating arteries was studied to provide anatomical foundation for clinical observation.Results 1.Sellar meningiomas mainly receive blood supply from the meningeal branches through the tumor base,also receive the subarachnoid branches arising from the ICA system through the tumor capsule which are thin and have no cressitude trunk. 2. pituitary adenoma and craniopharyngioma mainly receive blood supply from perforating arteries of SHA,PcoA,AChA,and proximal portion of ACA.3.Many small perforating arteries arising from the cycle of Willis. Some of these perforators onlysupply the tumor,enter the tumor directly,or prowl a varied distance on the surface of tumor capsule before entering it. While others can arise as common trunk,branches of which supply both the tumor and normal brain tissue. There are also some pass-by perforating arteries merely adhere to the tumor capsule but do not send branches into the tumor. 4. In this series,a posterior communicating artery in a patient with huge pituitary adenoma enters the tumor and send branches to supply the tumor. 5. Blood supply from the perforating arteries of posterior cerebral artery or bifurcation of basilar artery to tumor were observed in a case of pituitary adenoma and two cases of craniopharyngioma. 6.The observation of cadaveric brain is identical to other scholars.Conclusion 1. The blood supply to sellar tumors closely relate to their location.2. pituitary adenoma and craniopharyngioma have intimate relation with the cycle of Willis,which is one of the major obstacle in operation.3. Larger sellar meningioma mainly receive blood supply both from the internal and external carotid system. 4. The relationship between sellar tumors and the surrounding vessels can be pass-by,adhesion,encasement and engulf. 5. Pituitary adenoma and craniopharyngioma mainly receive blood supply from the anterior cycle of Willis. 6. Large pituitary adenoma and craniopharyngioma can receive blood supply from the posterior cycle of Willis.