Tumor Excisionneurosurgeon

The third portion of the craniocervical approach to jugular foramen tumors is performed by the neurosurgeon of the skull base team. Any remaining bone over the posterior aspect of the jugular bulb is removed with a high-speed drill to better expose the jugular bulb/jugular vein junction (Fig. 82-5A). A small, low retrosigmoid suboccipital craniotomy extending to the foramen magnum can be performed to gain proximal isolation of the lower CNs. For tumors that occlude the inferior portion of the sigmoid sinus, the internal jugular vein is ligated and transected in the neck (Fig. 82-5B). In instances in which the tumor is on the dominant side of venous drainage an attempt should be made to preserve the sinus. The sigmoid sinus is ligated below the level of the superior petrosal sinus by opening the dura anterior (retro-labyrinthine) and posterior to the sinus, allowing the placement of hemoclips or sutures. All venous pathways, except the inferior petrosal sinus, are thus isolated so that the internal jugular vein and sigmoid sinus can be opened and tumor sharply dissected. The medial wall of the jugular bulb remains intact to preserve

Figure 82-5 (A) After tumor is removed from the retrofacial air cells, any residual bone covering the jugular bulb is removed with a high-speed drill. This exposes the jugular bulb/jugular vein junction. (B) The sigmoid sinus is ligated below the pet-rosal sinus with hemoclips, and the internal jugular vein (IJV) is ligated below the pole of the tumor. The vein and sinus are opened along their length, and tumor is removed, revealing three to five inferior petrosal sinus (IPS) orifices. Bleeding from these orifices is controlled by packing with Oxy-cel and bone wax. The medial wall of the sinus is left intact with the posterior fossa dura. (C) The tumor is peeled from inferior to superior by dissecting from cranial nerves IX through XII and arterial feeders from the ascending pha-ryngeal artery. (ICA = internal carotid artery.) (D) The dura over the pars nervosa and IPS is incised with a No.15 blade to expose tumor intracranially in the jugular foramen along cranial nerve IX. A bone punch removes the occasional osseous bridge that divides the jugular foramen into pars nervosa and pars venosa compartments. (PICA = posterior inferior cerebellar artery.) (Reprinted with permission from Tew, et al.84)

the orifices (usually 3 to 5) of the inferior petrosal sinus. Brisk venous bleeding encountered from the IPS is controlled with Oxycel cotton (Becton-Dickinson, Franklin Lakes, NJ). Care is taken to avoid overpacking the IPS that, thus, causes cranial nerve damage. Sharp dissection separates tumorous attachment to CNs IX through XII (Fig. 82-5C). Remaining tumor is dissected from the cranial nerves as they are traced intracranially from the jugular foramen to their extracranial course (Fig. 82-5D).

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