A Prospective Study to Examine the Association of the Foramen Ovale Size with Intraluminal Pressure of Pear-Shaped Balloon in Percutaneous Balloon Compression for Trigeminal Neuralgia

Introduction: Percutaneous balloon compression (PBC) is an effective and safe option for patients with trigeminal neuralgia. A pear-shaped balloon can be used to identify the proper compression of the Gasserian ganglion during the PBC procedure. The aim of this study was to evaluate the relationship between the foramen ovale (FO) size and intraluminal pressure of the pear-shaped balloon.

Methods: Thirteen patients that presented with classical trigeminal neuralgia were scheduled to undertake PBC surgery at the Pain Department of the Third Xiangya Hospital, Central South University, from November 2020 to April 2021. Three-dimensional computed tomography reconstruction of the skull base was performed to capture the feature of FO preoperatively. The intraluminal pressure was continuously recorded when a pear-shaped balloon was obtained during the procedure. Correlation analysis was calculated to determine the association of the intraluminal balloon pressure with FO parameter.

Results: All participants reported complete relief of pain at discharge. The enduring analgesic effect of PBC was maintained in all patients with a median follow-up up to 5.5 months (range, 3-8 months). The average intraluminal balloon pressure was 161.5 ± 29.4 kPa at the initial compression (P1), and 134.8 ± 21.5 kPa at the ending of compression (P2), respectively. P1 was significantly correlated with the length (r = 0.61, P = 0.024) of FO. Similarly, a significant and positive correlation was observed between P2 and the length (r = 0.63, P = 0.022) of FO.

Conclusions: Preoperative assessment of FO may be a potential predictor of intraluminal pressure to reach a pear-shaped balloon during PBC treatment. Narrow FO is associated lower intraluminal balloon pressure.