gms | German Medical Science

Objective: Controversies regarding venous compression as the cause of trigeminal neuralgia (TN) still exist. The study was designed to analyze the success rate of microvascular decompression (MVD) for TN caused by offending veins.

Method: Between 2004 and 2015 167 patients had received surgery for TN at our institution. Only patients with pure venous compression were included in the study. MRI, Video recordings and operative reports were analyzed regarding the type of offending vein, anatomical conditions, compression site and surgical procedure. Demographic data, quality of pain, complications and follow-up data were analyzed.

Results: The study identified 29 patients with a mean history of TN of 7.9 years (male: female ratio: 8:21; average age 56 years). Pontine veins were found in 21 patients and petrosal veins in the remaining patients respectively. Proximal compression of the trigeminal nerve at the root entry zone could be observed in 15, distal compression in 11 and combined in 3 patients. MVD consisted of cauterization and cutting the vein, Teflon placement between nerve and vein or simply cutting surrounding arachnoid layers (14:14:1). 26 patients had an immediate excellent or good pain relief. Three patients reported no change. Complications occurred in 6 patients. Transient morbidity was observed in 3 patients. There was no mortality or functionally relevant permanent morbidity. The most dangerous complication occurred after cauterization/cutting of a petrosal vein resulting in a cerebellar swelling following venous congestion that fortunately resolved. Mean follow-up of all patients was 34.4 months (range:1-144months). Four patients reported recurrent pain up to 7 years after primary intervention. Two underwent a re-operation but partially improved.

Conclusions: Immediate improvement of pain was observed in 89.7% of the patients. The success of MVD was neither related to the kind of surgical procedure nor to venous or local anatomy. The study demonstrates that venous compression plays an underestimated role in trigeminal neuralgia and frequently responds to MVD. However, long-term follow-up is needed.