Nerve Combing for Trigeminal Neuralgia via “Peeling” of the Middle Fossa: A New Strategy for Failed Prior Microvascular Decompression

Introduction: Traditionally, microvascular decompression and trigeminal nerve combing for primary trigeminal neuralgia have been well described via a retrosigmoid approach. The aim of this paper is to describe a stepwise, microscopic cadaveric dissection along with nerve combing of the trigeminal nerve and the Gasserian ganglion, by “peeling” the middle fossa.

Methods and Materials: Microsurgical dissection was performed on five freshly injected cadaveric heads at the Skull Base Laboratory of the Department of Neurosurgery at Cleveland Clinic Florida. “Peeling” of the middle fossa was conducted, followed by opening the Meckel's cave. The nerve combing was performed from the root entry zone up to the Gasserian ganglion.

Results: Nerve combing of the trigeminal nerve was successfully done from the root entry zone to the Gasserian ganglion via a middle fossa approach. The essential steps of this approach include: (1) “Peeling” of the middle fossa via Hakuba technique. (2) Opening of the Meckel’s cave. (3) Anterior petrosectomy to enlarge the field of dissection. (4) Trigeminal nerve combing, which was performed from the cisternal segment to the Gasserian ganglion ([Figs. 1]–[4]).

Conclusion: Nerve combing for patients with trigeminal neuralgia via “peeling” of the middle fossa, affords a direct route to access both the cisternal segment of the trigeminal nerve and the Gasserian ganglion. It represents a new strategy for patients with partial remission or recurrence of pain after a retrosigmoid approach for MVD.

Fig. 1 Right side. The cadaveric specimen was rotated 45 degrees to the contralateral side. A pterional craniotomy was performed to access the middle fossa, where the “peeling” was planned.

Fig. 2 The “peeling” of the middle fossa was made, exposing the gasserian ganglion (*) and the three segments of the trigeminal nerve. The Hakuba technique was used. The middle meningeal artery (MMA) represented an essential landmark. V1, ophthalmic nerve; V2, maxillary nerve; V3, mandibular nerve.

Fig. 3 The Meckel's cave (*) was opened from lateral to medial (curve arrow), detaching it from the tentorium. CavSin, cavernous sinus; ICA, internal carotid artery; III, oculomotor nerve; IV, trochlear nerve.

Fig. 4 The gasserian ganglion and the cisternal segment of the trigeminal nerve are shown. The nerve combing of the trigeminal nerve was done proximal to distal (straight arrow). The nerve was split into six to eight bundles longitudinally along its fibers.

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Artikel online veröffentlicht:
05. Februar 2024