Do bubbles matter amid PBC for trigeminal neuralgia?

BACKGROUND: As a simple and safe alternative intervention, percutaneous balloon compression (PBC) has been gradually adopted by a growing number of neurosurgeons to treat trigeminal neuralgia. A pear-shaped opacity observed fluoroscopically, which indicates full suffusion of Meckel's cave conducting sufficient pressure against Gasserian ganglion, is believed to be the key to its success. Sometimes, a bitten pear may appear due to bubbles in the balloon but is usually ignored. OBJECTIVE: This study aims to investigate the effects of the bubbles on postoperative outcomes. METHODS: Patient data were obtained from the consecutive cases undergoing PBCs in our department between 2019 and 2021. Among them, pain and numbness were used to assess the efficacy of PBC based on Barrow Neurology Institute (BNI) scoring system. It was defined as an effective outcome if the postoperative pain intensity grade was lower than II. And those with numbness grade > II were regarded as numb incidence. RESULTS: We eventually recruited 59 cases, including 42 in full pear and 17 in bitten pear groups with follow-up time up to 44 months. The early effective rates were 95.2% and 82.4%, respectively (p > 0.05), which turned to 88.1% and 52.9% during the last follow-up period (p < 0.01). This result indicated that the bitten pear gave rise to a significantly higher recurrence. In terms of numbness, there was no significant difference. CONCLUSION: Gas does not yield enough pressure as liquid, and cannot exert enough pressure to the semilunar ganglion. Therefore, air evacuation should not be ignored before injection.