The petro-occipital trans-sigmoid approach for lesions of the jugular foramen

Abstract

This study's goals were twofold: (1) to analyze the author's experience with the petro-occipital trans-sigmoid (POTS) approach for the resection of tumors arising in or adjacent to the jugular foramen, and (2) to define the anatomical sites exposed by this approach. A retrospective review was conducted of 61 patients with jugular fossa tumors that included lower cranial nerve schwannomas, paragangliomas, meningiomas, chordomas, cholesteatomas, and other benign or low-grade malignant tumors. Outcome measures were mortality, morbidity, and long-term outcomes. No deaths were found in this study. The major morbidity was deficits of the glossopharyngeal, vagus, and accessory nerves. Hearing and facial nerve function were largely preserved. The resections were undertaken as single-stage procedures regardless of whether the tumor was entirely extradural or both intra- and extradural. None of the patients had central nervous system complications. Good outcomes were achieved for schwannomas, meningiomas, chondrosarcomas, and papillary adenoma. Chordomas tended to recur, and only class C1 paragangliomas could be removed using this approach. The study found that the POTS approach should be considered the approach of choice for many tumors in the region of the jugular foramen, particularly schwannomas. It is not suitable for the resection of malignant tumors and most paragangliomas because it offers limited access to the skull base between the jugular fossa and carotid canal.

Keywords: Jugular foramen; petro-occipital trans-sigmoid approach; surgical procedures; tumors of jugular foramen.

Figure 1

Extent and direction of the infratemporal type A (short arrow) and petro-occipital trans-sigmoid (long arrow) approaches as shown in an axial computed tomography of the skull base.

Figure 2

The surgical field from the skin to the dura. The skin flap (SF) is raised anteriorly, and the musculoaponeurotic flap (MF) is turned caudally. The bone removal includes a retrosigmoid craniotomy and a posterolateral petrosectomy up to the posterior semicircular canal, the antrum, fallopian canal (FC), and the posterior wall of the outer ear canal. The sigmoid sinus (SS) runs across the field, and the dotted line shows the dura incision. The jugular vein (JV) is ligated in the upper neck. PSC, posterior semicircular canal. (Reprinted from Mazzoni A, Sanna M. A posterolateral approach to the skull base: the petro-occipital transsigmoid approach. Skull Base Surg 1995;5:157–167.)

Figure 3

Dural flaps have been retracted and cerebellopontine angle (CPA) exposed to show cranial nerves V and VII to XI, anteroinferior cerebellar artery (AICA), posteroinferior cerebellar artery (PICA), and basilar artery (BA) with perforating branches to the brainstem. Following removal of jugular vein and bulb, the low clivus (CL) is exposed. The occipital condyle is covered by caudal dural flap. The facial nerve (FN) can be raised from fallopian canal, and tympanic bone removed as far as the tympanic annulus. This improves access to infratubal portion of carotid canal. ICA, internal carotid artery; LSC, lateral semicircular canal; PSC, posterior semicircular canal; SS, sigmoid sinus; V, trigeminal nerve; VII, facial nerve; VIII, cochleovestibular nerve; IX, glossopharyngeal nerve; X, vagus nerve; XI, spinal accessory nerve. (Reprinted from Mazzoni A, Sanna M. A posterolateral approach to the skull base: the petro-occipital transsigmoid approach. Skull Base Surg 1995;5:157–167.)

Figure 4

Surgical view after posterior petrosectomy and retrosigmoid craniotomy (RSC), left side. L, labyrinth and petrous dura; SS, sigmoid sinus medial wall.