Fig. 7

 A-C type VI sinus confluence meningioma; D-E meningioma completely blocked the posterior third of the superior sagittal sinus, forming a collateral circulation; and the meningioma compressed the left transverse sinus abnormally thin; F-H pre-operative cerebral angiography, suggesting the absence of the posterior third of the superior sagittal sinus, with a small amount of compensated venous collateral drainage to the straight sinus; I-L intraoperative resection process of the tumor, removing the tumor together with the superior sagittal sinus, without sinus reconstruction; M-O complete post-operative resection of the meningioma; P-Q post-operative absence of the posterior third of the superior sagittal sinus, with a small amount of venous collateral circulation to the straight sinus