The Efficacy of Trigger Site Surgery in the Elimination of Chronic Migraine Headache: An Update in the Rate of Success and Failure.

Migraine headache (MH) is a prevalent neurovascular disorder that affects approximately 15% of the global population. They are more common in women and typically affect young and middle-aged individuals. Chronic MH is characterized by headaches occurring on ≥15 days per month for over three months. While only 5% of MHs are refractory, about 20%-50% do not respond to pharmacologic treatments. As a result, surgical interventions have emerged as an alternative method to eliminate MH since 2000 AD. These surgical treatments primarily target the peripheral mechanisms of MH, focusing on common trigger sites. Migraine surgery involves neurolysis of sensory branches of trigeminal and occipital nerves that supply the face and back of the head. Numerous clinical studies conducted between 2000 and 2021 have extensively described surgical interventions and their prognostic outcomes. After surgery, up to 80% of patients reported complete elimination of headaches, while 20%-35% experienced no relief. The failure to achieve complete elimination of MH can be attributed to various factors. The most common reason for a partial clinical response is the failure to identify all trigger sites or inadequate surgery on the trigger sites. In this review, we aim to provide an overview of current surgical interventions for MH at different trigger sites, including recent updates, success and failure rates, and potential causes of failure.