Pain-Free Outcomes after Surgical Intervention for Trigeminal Neuralgia: A Comparison of Gamma Knife and Microvascular Decompression

Introduction: Trigeminal neuralgia (TN) is characterized as debilitating paroxysmal facial pain distributed amongst one or more of the three branches of the trigeminal nerve. Medical and surgical interventions exist that can provide symptomatic relief. The most common surgical options are microvascular decompression (MVD) and gamma knife surgery (GKS). Currently, there is no definitive consensus as to which of the two options is more effective at providing immediate and long-lasting pain relief. This study seeks to better evaluate the differences between these two options in terms of rates of complete pain relief and pain free recurrence.

Materials and Methods: A systematic review and meta-analysis was conducted on published studies of MVD and GKS for treatment of TN from 2004 to 2014. Cases were selected using a MEDLINE/PubMed search, as well as, from subsequent inspection of the references from articles found in the initial search. Data were extracted regarding rates of complete pain relief and pain-free recurrence. Complete pain relief was defined as being pain free without the use of medication. Pain-free recurrence was defined as initially experiencing complete pain relief with a subsequent recurrence of pain.

Results: A meta-analysis was performed for rates of patients who were initially pain free, never pain free, experienced pain-free recurrence, and were pain free at last follow-up. A total of 18 articles with a total of 2,650 patients were included in the MVD group while 25 articles with a total of 2,846 patients were included in the GKS group. MVD was found to have a significantly higher rate of initial pain free outcomes as compared with GKS (92.22 vs. 61.46%, p < 0.0001) as well as a significantly lower rate of patients who were never completely pain free (8.88 vs. 44.14%, p < 0.0001). MVD was also found to have a significantly lower pain-free recurrence rate as compared with GKS (14.93 vs. 19.38%, p < 0.0001). In addition, MVD was also found to have a significantly higher rate of long-term pain-free outcome at last follow-up as compared with GKS (79.37 vs. 41.62%, p < 0.0001).

Conclusion: Overall, MVD may be a more effective intervention than GKS because of higher rates of initial pain-free and long-term pain-free outcomes at last follow-up, and lower rates of patients who were never pain free and those that experienced pain-free recurrence.