Pterion Prep CraniPro VUMC Case Prep
2026-06-27

Case Prep: Microvascular Decompression (MVD) for Trigeminal Neuralgia

Case / Approach Snapshot

One-Liner

[Age]yo [M/F] with [left/right] trigeminal neuralgia ([V2/V3/V2-V3]) refractory to medical management planned for [left/right] retrosigmoid craniotomy for microvascular decompression.

Figures, Imaging & Video

🎥 Operative video — search operative video on YouTube ▸ · The Neurosurgical Atlas ▸

🧭 Operative approach: Retrosigmoid craniotomy — detailed corridor setup, step-by-step technique & figures

Neurosurgical Atlas · Radiopaedia · PubMed Central — operative figures © linked; see media-sources.md

High-Yield Literature

Curated Image Set

Open-access figures are embedded from PubMed Central articles and kept unique to this guide.

Microvascular Decompression Trigeminal Neuralgia — Fig. 1 Fig. 1. Representative intraoperative images of a artery compression and vein close, b vein compression, and c arachnoid adhesions Source: Arterial compression of nerve is the primary cause of trigeminal neuralgia — Neurological Sciences 2013; CC BY.

Microvascular Decompression Trigeminal Neuralgia — Rule of Three concept Fig. 3. “Rule of Three” framework for tailored MVD approaches to major neurovascular compression syndromes. Source: Historical evolution of microvascular decompression after Jannetta’s establishment: Anatomical maps and physiological compasses-a narrative review — Acta Neurochirurgica 2026; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — noncompressive transposition Fig. 5. Noncompressive transposition technique after MVD, illustrating transposition rather than simple interposition. Source: Historical evolution of microvascular decompression after Jannetta’s establishment: Anatomical maps and physiological compasses-a narrative review — Acta Neurochirurgica 2026; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — Fig. 1 Fig. 1. Neuroimaging findings in a representative patient with TN secondary to MS possibly due to a double crush mechanism. 3D time-of-flight (TOF) magnetic resonance angiography scans (a) and… Source: Trigeminal neuralgia secondary to multiple sclerosis: from the clinical picture to the treatment options — The Journal of Headache and Pain 2019; CC BY.

Microvascular Decompression Trigeminal Neuralgia — Fig. 2 Fig. 2. Voxel-based analysis in patients with TN secondary to MS. Voxel-based brainstem model in patients with TN secondary to MS (TN group, n = 42) and in patients with trigeminal sensory… Source: Trigeminal neuralgia secondary to multiple sclerosis: from the clinical picture to the treatment options — The Journal of Headache and Pain 2019; CC BY.

Microvascular Decompression Trigeminal Neuralgia — Figure 1 Figure 1. Patient 1: (A) Three-dimensional time-of-flight magnetic resonance angiography findings. Anterior inferior cerebellar artery compresses the right trigeminal nerve, left side was… Source: Unilateral Approach to Primary Bilateral Trigeminal Neuralgia Via Bilateral Microvascular Decompression — The Journal of Craniofacial Surgery 2022; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — Figure 2 Figure 2. Patient 2: (A) Three-dimensional time-of-flight magnetic resonance angiography findings. Superior cerebellar artery compressed the left trigeminal nerve. (b) Contralateral trigeminal… Source: Unilateral Approach to Primary Bilateral Trigeminal Neuralgia Via Bilateral Microvascular Decompression — The Journal of Craniofacial Surgery 2022; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — Figure 6 Figure 6. Source: Acupuncture treatment on idiopathic trigeminal neuralgia: A systematic review protocol — Medicine (Baltimore). 2019 Jan 25;98(4):e14239. doi: 10.1097/MD.0000000000014239; CC BY.

Microvascular Decompression Trigeminal Neuralgia — Figure 1 Figure 1. A Passage of the needle through the lateral part of the foramen ovale, B advancement of the needle towards the Gasseri ganglia, C position of the needle for radiofrequency ablation of… Source: TREATMENT OPTIONS FOR TRIGEMINAL NEURALGIA — Acta Clinica Croatica 2022; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — Figure 9 Figure 9. Source: Microvascular Decompression: Salient Surgical Principles and Technical Nuances — J Vis Exp. 2011 Jul 5;(53):2590. doi: 10.3791/2590; CC BY-NC-ND.

Microvascular Decompression Trigeminal Neuralgia — Figure 10 Figure 10. Source: Microvascular Decompression: Salient Surgical Principles and Technical Nuances — J Vis Exp. 2011 Jul 5;(53):2590. doi: 10.3791/2590; CC BY-NC-ND.

History of Present Illness

Past Medical History

Imaging Review

MRI Brain with Thin-Cut Posterior Fossa Sequences

MRA / CTA

Audiology

Labs

Neurological Examination

Trigeminal Nerve (CN V)

Other Cranial Nerves (Posterior Fossa)

Cerebellar

Surgical Planning

Case Logistics, OR Needs & Orders

Diagnosis & Indication

Position

Incision

Approach: Retrosigmoid Craniotomy

Key Surgical Steps

  1. Incision — retromastoid curvilinear, centered on asterion
  2. Suboccipital craniectomy/craniotomy — ~2.5 x 2.5 cm
    • Expose the junction of the transverse and sigmoid sinuses
    • Keyhole burr hole just inferior and medial to the asterion
    • Bone removal to expose the edge of the sigmoid sinus laterally and transverse sinus superiorly
  3. Dural opening — curvilinear, based on sigmoid/transverse sinus junction
  4. CSF drainage — open cisterna magna or lateral cerebellomedullary cistern early for cerebellar relaxation
  5. Cerebellar retraction — MINIMAL, gravity-assisted; brain relaxes after CSF drainage
  6. Identify CN V — follows the trigeminal nerve from the pons to Meckel’s cave
  7. Identify the offending vessel:
    • SCA: Most commonly compresses from superiorly or superomedially at the REZ
    • AICA: Compresses from inferiorly or laterally
    • Vertebral/basilar: Large vessel indentation
    • Vein: May run along the nerve
    • Look for nerve compression, distortion, or grooving at the REZ (proximal 5mm of nerve where central myelin transitions to peripheral myelin)
  8. Mobilize the offending vessel — gently dissect the vessel away from the nerve
  9. Place Teflon felt pledget — interpose between the vessel and the nerve to prevent re-contact
    • Shape and size the Teflon to keep the vessel displaced
    • Do NOT pack Teflon too tightly (can cause new compression)
  10. Inspect for additional compressive vessels — multiple vessels may be present
  11. If venous compression: Decision to coagulate and divide vs. transpose. Veins are harder to decompress; petrosal vein sacrifice is sometimes necessary but risks venous infarction
  12. If NO clear offending vessel found:
    • Inspect thoroughly (360 degrees around nerve)
    • Consider arachnoid bands causing tethering
    • May still decompress (some occult compression)
    • Consider partial sensory rhizotomy as adjunct (less preferred)
  13. Hemostasis and inspection — ensure no bleeding, cerebellar surface intact
  14. Dural closure — watertight (primary or with dural graft)
  15. Cranioplasty — replace bone or methylmethacrylate/titanium mesh over defect
  16. Standard closure

Critical Anatomy & Structures at Risk

  1. Trigeminal nerve (CN V) — the nerve being decompressed; avoid manipulation/traction
  2. CN VII/VIII complex — runs inferior to CN V in the CPA; at risk during approach
  3. AICA — gives off the labyrinthine artery (supplies inner ear); avoid compression or vasospasm
  4. Superior petrosal vein (Dandy vein) — drains lateral cerebellar surface; sacrifice may be needed for exposure but risks venous infarction
  5. Cerebellar surface — avoid excessive retraction
  6. Sigmoid and transverse sinuses — lateral and superior limits of craniotomy; injury causes hemorrhage
  7. Vertebral artery — deep in the CPA; at risk with large vessel decompression
  8. Brainstem — medial limit; avoid any instrument contact

Equipment

Monitoring

Anesthesia Considerations

Potential Complications & Contingencies

  1. Hearing loss — AICA/labyrinthine artery compromise; monitor BAER; if changes, release retraction, check vessel
  2. Facial nerve palsy — traction injury during approach; gentle technique, monitor EMG
  3. CSF leak — watertight dural closure; if leak post-op, may need lumbar drain or wound revision
  4. Cerebellar hematoma/edema — minimize retraction; if post-op deficit, emergent CT
  5. Aseptic meningitis — chemical irritation from Teflon; steroids, supportive care
  6. Incomplete relief — ~70-80% pain-free at 5 years; recurrence may need reoperation or radiosurgery
  7. Facial numbness — usually from nerve manipulation; typically mild and improves
  8. Venous infarction — from petrosal vein sacrifice; minimize vein sacrifice

Operative Note Template

Preoperative Diagnosis: [Left/Right] trigeminal neuralgia (Type 1), medically refractory

Postoperative Diagnosis: Same; [SCA/AICA/vertebral artery/vein] compression of [left/right] trigeminal nerve at the root entry zone identified and decompressed

Procedure: [Left/Right] retrosigmoid craniotomy for microvascular decompression of the trigeminal nerve

[Include: positioning details (park bench), craniotomy size, CSF drainage, CN V identification, offending vessel identification and characterization (SCA/AICA, direction of compression, groove/distortion on nerve), Teflon pledget placement, BAER monitoring stability, watertight closure]

Postoperative Plan

Chief-Level Case Review

Use these as the senior-level mental model for Microvascular Decompression (MVD) for Trigeminal Neuralgia:

Common Pimp Questions

Use these to pressure-test preparation for Microvascular Decompression (MVD) for Trigeminal Neuralgia:

  1. What is the proximal-control plan before the lesion is manipulated?
  2. Which branch, perforator, or venous structure is most likely to be injured in this exposure?
  3. What are the intraoperative rupture steps, including temporary clip, suction, BP, and backup clip strategy?
  4. What confirms treatment success: ICG, Doppler, puncture/deflation, DSA, or postoperative CTA?
  5. What postoperative BP, vasospasm, antiplatelet, or anticoagulation issue changes the orders tonight?

Attending Preference Variables

Items that commonly vary by surgeon or institution: