After The Sigmoid Sinus Approach Vein And Related Structural Microdissection And Clinical Application

Objective:To study composition of vein and adjacent structure in suboccipital retrosigmoid approach, analyze anatomical characteristics of these veins and the relationship with surronding nerves, blood vessels. To explore the possible impact of posterior fossa venous systerm and its variation in surgical treatment of intracranial lesions.Methods:The suboccipital retrosigmoid approach were simulated in15(30hemispheres) formalin fixed adult cadaveric brains in which the cerebral arteries and veins had been perfused respectively with red and blue latex. The vein of posterior cranial fossa and its related branches and traveling, were observed under an operating microscope. The composition of vein of petrosal and cerebellum related to it were analyzed and measursed. Object to summarize and grasp the role of vein in lesion localization and surgical guidance.Results:There is three parts in the anatomy of the vein in suboccipital retrosigmoid approach.(l)The initial segment:including of transverse sinus, sigmoid sinus and occipital superficial vein of cerebellar hemisphere.(2)The middle segment:including of surronding and superficial vein of brainstem.(3)The basal segment:including of petrosal vein, petrosal sinus and inferior petrosal sinus. The juction with transverse sinus and sigmoid sinus can point the position of key-hole in craniotomy, path and shape of brainstem vein may be changed by the oppression of cerebellopotine angle lesions, the petrosal vein may lead to trigeminal neuralgia.Conclusion:(1)Composed of posterior cranial fossa venous systerm has a large variation and anastomotic branch, which is particularly evident in cerebellar superficial vein.(2) Some vein has a close relationship with clinical lesions, such as petrosal vein.(3)Some vein can guide surgical procedure accurately and effectively, such as the junction of transverse sinus and sigmoid sinus.(4)Some important vein should be kept to prevent postoperative complications, even if there was so much anastomotic vein.(5)Complex strutures in the cerebellopontine angle region, it is necessary that perfect preoperative imageing examination and improve microanatomy skill.