Petrosal Vein Involvement in Neurovascular Conflict in Trigeminal Neuralgia: Surgical Technique and Clinical Outcomes

Abstract

BACKGROUND Contact of the main stem of the petrosal vein (PV) to the nerve root is a rare cause of trigeminal neuralgia (TGN). The implication of the PV in relation with neurovascular contact (NVC) is not fully understood. OBJECTIVE To assess the operative procedures in microvascular decompression (MVD) in patients with PV involvement in the long-term. METHODS We retrospectively reviewed 34 cases (7.0%) in 485 consecutive MVDs for TGN, whose PV main stem had contact with the trigeminal nerve root (PV-NVC). PV-NVCs were divided into 2 groups: concomitant arterial contact or no concomitant arterial contact. Surgical techniques, outcomes, complications, and recurrence were assessed. RESULTS The anatomical relationship of the PV with the trigeminal nerve root was consistent with preoperative 3-dimensional imaging in all patients. Pain relief was obtained in most patients immediately after surgery (97.1%) by separating the PV from the nerve root. Postoperative facial numbness was noted in 9 patients (26.5%). Symptomatic venous infarctions occurred in 2 patients (5.9%). Recurrence of facial pain occurred in 3 patients (8.8%) with a median 48 mo follow-up period. Re-exploration surgery revealed adhesion being the cause of recurrence. The statistical analyses showed no difference in the surgical outcomes of the 2 groups. CONCLUSION Separating the PV from the nerve root contributes to pain relief in patients with PV conflict regardless of concomitant arteries. Preserving venous flow is crucial to avoid postoperative venous insufficiency.

Venous Flow Conversion Technique for Sacrificing the Superior Petrosal Vein During Microvascular Decompression for Trigeminal Neuralgia

“…The usefulness of cutting the TPV during MVD, including our report, 9,28 has been investigated, but maintaining the venous return of the SPV is unclear. We here propose a hypothesis for the safe sacrifice of the SPV based on the TPV's ability to provide compensatory collateral flow pathways.…”

Very early re-do microvascular decompression for patients with trigeminal neuralgia

“…Shorter vein cannot be easily stretched, while forced displacement or direct coagulation may damage venous refluxes and result in severe complications and even death. [23][24][25] The vein was only slightly separated in the first operation. When there is no pain relief, we totally separated it during re-do operation.…”

Dural arteriovenous fistula presenting as trigeminal neuralgia: Case report and literature review

“…MVD can be used for patients whose pain is not relieved after interventional embolization. A study by Fukushima et al found that separating the petrosal vein from the nerve root contributes to pain relief in patients with petrosal vein conflict, regardless of the accompanying artery [ 30 ]. Different from what is seen in primary TN surgery, the SPV often exhibits venous lake changes; after embolization, vein thrombosis forms and the texture becomes hard, making the SPV difficult to move and significantly increasing the difficulty of the operation.…”