Mobilization of the sphenoparietal sinus: a simple technique to preserve prominent frontobasal bridging veins during surgical clipping of anterior communicating artery aneurysms: technical case report.

Background And Importance: Bridging veins arising from the frontal base (frontobasal bridging veins, FBBVs) can pose obstacles when performing clipping of anterior communicating artery (ACoA) aneurysms via the pterional approach. Although FBBVs can in general be sacrificed without critical complications to achieve an adequate retraction of the frontal lobe, neurosurgeons sometimes encounter postoperative venous infarction or contusion of the retracted frontal lobe, which may be accounted for by the damage to the venous drainage system. Thus, preservation of intracranial veins is desirable to prevent postoperative venous complications, especially when they are prominent.

Clinical Presentation: A 66-year-old female patient was revealed to have multiple unruptured aneurysms at the ACoA, bilateral middle cerebral arteries, and the left internal carotid artery. In the first stage of the operation, clipping of the right middle cerebral artery and ACoA aneurysms was performed via a right pterional approach. Because the ACoA aneurysm was located at a high position and projecting posteriorly, a transsylvian "lateral" trajectory was preferred to a subfrontal "anterior" trajectory. Intraoperatively, her FBBV was revealed to be so prominent that the sacrifice would be harmful. Thus, we performed posteriorward displacement of the sphenoparietal sinus extradurally, thereby achieving adequate retraction of the frontal lobe intradurally without sacrificing the FBBV. With this simple technique, the ACoA aneurysm was successfully treated.

Conclusion: This technique is useful for retracting the frontal lobe sufficiently to enable establishment of an appropriate surgical field for a pterional approach to ACoA aneurysms with prominent FBBVs.