High jugular bulb in the translabyrinthine approach to the cerebellopontine angle: anatomical considerations and surgical management.
BACKGROUND
Evidence of a high jugular bulb position (HJBP) during the translabyrinthine approach may compromise the surgical removal of cerebellopontine angle (CPA) tumours. We report a simple surgical procedure to safely manage this frequent normal variation and comment on various alternative options.


METHODS
The translabyrinthine approach included a complete skeletonization of the sigmoid sinus and of the presigmoid dura. A thin eggshell bone was left at the jugular bulb surface. The dome of the jugular bulb was gently dissected from the jugular fossa and gradually retracted downward in a tailored way, allowing the surgeon to drill below the internal auditory meatus. A small piece of bone was wedged over the jugular dome in order to maintain its lowered position.


RESULTS
Among 178 consecutive translabyrinthine approaches performed for the removal of large CPA tumors, the use of this procedure was required in 44 cases of HJBP. Excepting minimal venous bleeding easily controlled in several cases, we never observed any complication from this procedure nor failure to expose the inferior compartment of the CPA.


CONCLUSIONS
The HJBP can be systematically diagnosed with the preoperative CT-scan using bone window imaging. Our results demonstrate that the described procedure is safe and effective to widen the operative corridor that is required for the exposure of the inferior compartment of the CPA in this anatomical situation.
Service de Neurochirurgie, Centre Hospitalier Sainte Marguerite, Marseille, France. proche@mail.ap-hm.fr
P-H
PH
Roche
T
T
Moriyama
J-M
JM
Thomassin
W
W
Pellet
D000328:Adult; D020785:Central Nervous System Vascular Malformations / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery; D002530:Cerebellopontine Angle / Q000033:anatomy & histology / Q000473:pathology / Q000601:surgery*; D003388:Cranial Fossa, Posterior / Q000033:anatomy & histology / Q000601:surgery; D003392:Cranial Sinuses / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D007758:Ear, Inner / Q000033:anatomy & histology / Q000601:surgery; D005260:Female; D006801:Humans; D007431:Intraoperative Complications / Q000209:etiology / Q000503:physiopathology / Q000517:prevention & control; D007601:Jugular Veins / Q000002:abnormalities* / Q000000981:diagnostic imaging / Q000601:surgery; D008297:Male; D009464:Neuroma, Acoustic / Q000175:diagnosis / Q000503:physiopathology / Q000601:surgery*; D019635:Neurosurgical Procedures / Q000009:adverse effects / Q000379:methods* / Q000592:standards; D010579:Petrous Bone / Q000033:anatomy & histology / Q000601:surgery; D011300:Preoperative Care / Q000379:methods / Q000592:standards; D011859:Radiography; D012189:Retrospective Studies; D014656:Vascular Surgical Procedures / Q000009:adverse effects / Q000379:methods* / Q000592:standards