I ran into the following abstract today at AANS. http://www.aans.org/Media/Article.aspx?ArticleId=64781 .
Although this is from a "small" series, the team reporting the work is among the most experienced in MVD in the world. The report is consistent with several others I've read, and with conversations I've had in years past with Dr. Janetta.
Regards and best,
Red
Microvascular Decompression after Failed Gamma Knife Radiosurgery for Trigeminal Neuralgia
Author(s):
Raymond F. Sekula, MD
Andrew M. Frederickson, BS
Peter J. Jannetta, MD
Sanjay Bhatia, MD
Matthew R. Quigley, MD (Pittsburgh, PA)
Introduction: Clinicians are faced with the problem of choosing a subsequent treatment plan if Gamma Knife radiosurgery (GKS) for trigeminal neuralgia (TN) fails. This study was conducted to identify whether microvascular decompression (MVD) is a safe and effective treatment after GKS.
Methods: Twenty-nine consecutive patients, over 2 years, underwent attempted MVD following failed GKS. During MVD, data regarding thickened arachnoid, adhesions between vessels and trigeminal nerve, and trigeminal nerve atrophy/discoloration were noted. Outcome and complication data were also recorded.
Results: MVD was completed in 28 patients (97%). Trigeminal nerve atrophy was noted in 14 patients (48%). Thickened arachnoid was noted in one patient (3%). Adhesions between vessels and the trigeminal nerve were noted in 6 patients (21%) and prevented MVD in one patient. At last follow-up (median 19.8 months), 15 patients (52%) reported an excellent outcome after MVD, 1 patient (4%) reported a good outcome after MVD, 2 patients (7%) reported a fair outcome after MVD, and 11 patients (39%) reported a poor outcome after MVD. After MVD, new or worsened facial numbness occurred in 6 patients (21%). Additionally, 3 patients (11%) developed new or worsened troubling dysesthesias. Complications included temporary facial palsy in one patient and an inability to complete MVD due to scarring between the SCA and trigeminal nerve in one patient (3.4%).
Conclusions: Thickened arachnoid, adhesions, and trigeminal nerve atrophy/discoloration due to GKS did not prevent completion of MVD. In this series, evidence for arachnoid thickening and adhesions caused by GKS alone is lacking. MVD is an appropriate and safe “rescue” therapy following GKS although the risks of numbness and troubling dysesthesias appear to be higher than with MVD alone.