Lariboisiere Hospital pre-operative surgical checklist to improve safety during transpetrosal approaches

Background: Transpetrosal approaches are technically complex and require a complete understanding of surgical and radiological anatomy. A careful evaluation of pre-operative magnetic resonance imaging and computed tomography scan is mandatory, because anatomical or pathological variations are common and may increase the risk of complications related with the approach. Methods: Pre-operative characteristics of venous and petrous bone anatomy were analysed and correlated with intraoperative findings, using injected magnetic resonance imaging and thin-slices computed tomography scan. These data regularly checked before each transpetrosal approach were progressively included in the presented checklist. Results: Transpetrosal approaches have been used in 101 patients. Items included in the checklist were petrous bone pneumatization, angle between petrous apex and clivus, dehiscence of petrous carotid artery, dehiscence of geniculate ganglion, distance between superior semicircular canal and middle fossa floor, distance between cochlea and middle fossa floor, sigmoid sinus dominance, transverse sigmoid sinus junction depth to the outer cortical bone, jugular bulb height (high or low), location of the vein of Labbé, characteristics of superior petrosal vein complex. Conclusion: The presented checklist provides a systematic scheme of consultation of characteristic of venous and petrous bone anatomy for transpetrosal approaches. In our experience, the use of this checklist reduces the risk of complications related with approach, by minimizing the neglect of crucial information.