Comparison between presigmoidal and retrosigmoidal approaches for exposing geniculate ganglion utilizing virtual reality skill
Abstract：Objective To compare microanatomy feature for exposing geniculate ganglion between presigmoidal and retrosigmoidal minimally invasive approaches by virtual reality technique .Methods CT and MRI scans were performed to 15 adult cadaver heads ,then image data was inputted into virtual real‐ity system to establish three -dimensional anatomy model of temporal bone .Surgical routes of presig‐moidal and retrosigmoidal approaches exposing geniculate ganglion were outlined by selecting osseous landmark points on the calvaria and skull base .Special form and sequence of anatomic structures were observed .Volumes of anatomic tissues were measured .Statistical comparison was launched by paired t test .Results Bone drilling through presigmoidal approach started with mastoid and avoided injury of sigmoid sinus and jugular bulb .The surgical route involved vertical segment of facial nerve ,ossicular chain ,labyrinth ,and then ,exposed facial nerve when arrived at geniculate ganglion .Routes simulating sigmoidal approach passed below the transverse sinus and lateral to cerebellum .When arrived at internal acoustic meatus ,the route performed bone drilling for petrous bone and involved facial -acoustic nerve complex .When reached geniculate ganglion ,the ossicular chain and labyrinth were exposed in the route . Measuring showed that the volumes of surgical route and labyrinth were larger in retrosigmoidal ap‐proach than those in presigmoidal approach .Volumes of facial -acoustic nerve complex and ossicular chain were larger in presigmoidal approach than those in retrosigmoidal approach .All above differences reached statistical significance (P < 0 .05) . Volume of cerebellum in retrosigmoidal approach was (462.72 ± 20 .87) mm3 .Presigmoidal approach did not involve cerebellum .NO significant differences were found in the volumes of osseous structures (not include ossicular chain ) between two approaches (P > 0 .05) .Conclusions To expose geniculate ganglion by petrous bone drilling ,presig‐moidal approach is helpful to reduce the injury of labyrinth .Retrosigmoidal approach is helpful to reduce the injury of ossicular chain and expose facial -acoustic nerve complex .
Keywords：Geniculate ganglionPresigmoidal approachRetrosigmoidal approachVirtual realityThree-dimensional anatomy
Publication Date：2016-01-01
Online Publishing Date：2025-08-15(First online date of this platform, not the publication date of the document)
Pages：3( 256-258 )