Introduction: The sigmoid sinus is frequently exposed and/or traversed in a number of approaches in skull base surgery. When performing approaches to the lateral and posterolateral skull base, it is essential to understand the normal topographic anatomy of the sigmoid sinus and its exposure from different intraoperative perspectives. We describe the anatomy of the sigmoid sinus and the optimal degrees of exposure, skeletonization, and displacement or ligation to enhance exposure in different neurosurgical approaches.
Methods: Posterior petrosectomies (translabyrinthine, retrolabyrinthine, transcochlear), a retrosigmoid, an extreme lateral, a petrooccipital transsigmoid, and a combined pre- and retrosigmoid approaches were performed on 6 adult cadaveric heads (12 sides). The optimal degrees of sigmoid sinus exposure, skeletonization and manipulation, and displacement or ligation to enhance exposure in each approach were assessed. Strategies for avoiding complications from injury to the sigmoid sinus when accessing deeper targets were also examined.
Results: The retrosigmoid, far lateral, and extreme lateral approaches require exposure of only the posterior and posteroinferior sigmoid sinus. Partial skeletonization of the sigmoid sinus is satisfactory in all approaches except in the retrosigmoid approach where complete skeletonization of the sinus is necessary.
Conclusions: Thorough knowledge of the anatomy of the sigmoid sinus and its intraoperative management can help surgeons achieve enhanced exposure of the surgical target while avoiding iatrogenic injury and effectively navigating the region surrounding the sigmoid sinus.
Patient Care: Understanding of the anatomy of the sigmoid sinus and its anatomical relationships can help surgeons better avoid intraoperative pitfalls and complications.
Learning Objectives: Thorough knowledge of the anatomy of the sigmoid sinus and its anatomical relationships can help surgeons better avoid intraoperative pitfalls and more effectively navigate the region surrounding the sigmoid sinus.