Microvascular Decompression for Trigeminal Neuralgia: Surgical Technique and Technical Tips

Since 1982, we have carried out 422 microvascular decompressions (MVDs) for trigeminal neuralgia (TGN) and have climbed the learning curve.

Imaging: MRI/MRA demonstrate vascular compression with 100% specificity and 95% sensitivity. Also look for petrous endostosis, which can obscure the trigeminal sensory root.

Key Principles: Expose and visualize the entire sensory root and remove all vessels that might be compressing. Aim to achieve a total decompression with no vessel or prosthesis touching the nerve. Be prepared to find no vascular compression in 10 to 15% of cases. In these cases a partial sensory rhizotomy (PSR) is performed.

Positioning and Approach: Semiprone park-bench position, surface marking—identify asterion and mastoid tip. Expose angle of transverse/sigmoid sinus via 2.5-cm craniotomy. Gently “turn the corner” using fine tapered retractor and following petrosal sinus pathway. Medial petrosal bridging veins can be preserved.

Technical Details of MVD: Use suction tip and ball dissector to remove superior cerebellar artery (SCA) from neural contact. Place the SCA on the tentorium and overlay with a Teflon wool sling plus fibrin glue. Compressive veins can be diathermied and divided with safety. If petrous endostosis is present (3.3%), use endoscopy or drill reduction: this frequently reveals a compressing vein. Seal mastoid air cells with muscle and glue 5–0 prolene and muscle patches to dura for watertight closure. Replace bone.

Results: Average hospital stay is 3.5 days. Long-term cure for MVD is 86%. Improvement is 9% and failure is 5%. Long-term cure for PSR is 85%, improvement is 13%, and failure is 2%. Average patient satisfaction is 92%. Mortality is zero. CSF leak is 1.9%. Deafness is 1.3%.

Conclusion: In the treatment of TGN, MVD is highly effective and very safe, but a learning curve is required.