Page 40 - WNS 2024 e-Program - Resized and Binded

Re-Do Microvascular Decompression (MVD) Surgery for
Recurrent/Persistent Trigeminal Neuralgia (TN): Pattern of
Failure (POF) Analysis and Operative Findings in 164 Re-Do
MVD’s over 18 Years
Mark E. Linskey, M.D.
University of California, Irvine
Heather Corsn, PA-C, Wendy Richardson, PA-C; University of California,
Irvine
Introduction: As more neurosurgeons perform MVD, persistent/recurrent
TN after first MVD attempt is becoming more common.
Objective: POF analysis.
Methods: 164 sequential re-do MVD’s for persistent/recurrent TN from
prospective database over 18 years, retrospectively analyzed. Retrosigmoid
craniectomy (RSC) with intra-operative ABR, monitoring. Endoscope
assisted (EA) in 59 (25%). Temporal bone dissection (TBD) in 7 (0.6%). Our
re-do 23 [14% - 2/23 (35%) pediatric, 16y-22y at re-do]. 141 (86%) initial
operation elsewhere. Intra-operative findings carefully documented &
photographed. Clinical evaluations, 3m, 1y, & annually. Pain relief for typical
neuralgic pain (TNP) & atypical neuralgic pain (ATNP), 0-10 scale.

Results: Shredded Teflon felt (TF) found in 75.6%, non-shredded TF
(15.9%), no material (8%), Ivalon 2 patients & Cellulose, Telfa, Dacron &
Gortex in 1 each. Two patients material on cranial nerves (CN) 7/8. Only 6
negative explorations (all our own). Multiple vessels identified 146 (89%).
Arteries & Veins 139 (84.8%). Veins only 16 (9.8%), Artery +/- unnamed
artery Branch(es) (UAB) only 8 (4.9%). 135 vessels dorsal/lateral proximal
third under Cerebellar Ala (CA). 95 vessels ventral/medial middle third, 76
vessels ventral/medial distal third. Failure to mobilize the CA was the
proximate cause in 78/164 (47.6%0 of patients. Re-do from elsewhere 70%
pain-free (PF) TNP and 50% ≥50% improved ATNP. Our own re-do MVD
only 30% pain-free (PF) TNP and ≥50% improved ATNP.
Conclusions: Not releasing tethering veins to mobilize the CA is the major
cause of technical failure of MVD for TN with failure to adequately expose/
explore the dorsal/lateral proximal third of the CN 5 shoulder-nerve root-
brainstem junction, followed by failure to appreciate the potential causal
nature of veins &/or UAB’s, followed by failure to explore the ventral medial
aspect of the nerve root, followed by poor distal exposure due to failure to
remove obscuring bone. Endoscopic assistance & TBD are useful adjuncts

The San Diego Model Railroad Museum boasts the largest model railroad
display in the entire world