1. 2022;25;E1279-E1287Meckel’s Cave Size Measured by Magnetic Resonance Imaging in the Prognosis of Percutaneous Balloon Compression for Trigeminal Neuralgia
   Retrospective Study
   Xiaochong Fan, MD, Zhongyuan Lu, MD, Huan Ren, MD, Fuxing Xu, MD, Lijun Fu, MD, Chunxiao Bu, MD, Yong Zhang, PhD, Qingying Liu, MD, Huilian Bu, MD, and Jingjing Yuan, MD.

BACKGROUND: Percutaneous balloon compression (PBC) is a safe and effective method to treat trigeminal neuralgia. Despite it is known that intraoperative balloon volume is crucial in the prognosis of PBC patients and correlates with Meckel’s cave (MC) size, it is a lack of objective and valid criteria for intraoperative balloon volume of PBC.

OBJECTIVES: The aim of this study was to evaluate the relationship between the size of MC and the volume of a pear-shaped balloon in improving the prognosis of patients receiving PBC.

STUDY DESIGN: Retrospective study.

METHODS: Patients were divided into 3 groups according to their prognosis, and simple linear regression equations were established separately. Group A was defined as having recurrence. Group B was defined as having no recurrence and a Barrow Neurological Institute facial numbness (BNI-N) score of <= 2. Group C was defined as having BNI-N > 2 with no recurrence. Correlation analysis was carried out to determine the association of the intraoperative balloon volume with MC size. We attempted to construct simple linear regression models after verifying that both parameters were in compliance with the requirements of this model.

RESULTS: Until the end of the 6-months follow-up, 60 patients (93.8%) reported no pain, and 4 patients (6.3%) experienced no significant pain relief. Sixteen (25.0%) patients had severe facial numbness, 48 (75.0%) patients had no facial numbness or had only mild numbness. All 3 groups had a significant correlation between balloon volume and MC size. Group A: Balloon volume (cm3) = -0.371 + 1.883*MC size (R2 = 0.882); Group B: Balloon volume (cm3) = 0.110 + 1.274*MC size (R2 = 0.861); and Group C: Balloon volume (cm3) = 0.011 + 1.835*MC size (R2 = 0.857).

LIMITATIONS: The main limitation of our study is its observational retrospective nature, and we were unable to further analyze the intraoperative balloon pressure and volume, as well as validate the accuracy of the model. In additional this was a single-center study with a small sample size and a short follow-up period. These may have contributed to the bias in the final results. A multicenter, prospective study with a large sample size should be performed to further investigate the long-term effects of individualized balloon volumes and the correlation between pressures.

CONCLUSIONS: The equation [balloon volume (cm3) = 0.110 cm3 + 1.274*MC size] yields an appropriate value at which the patient has a low recurrence rate and a low degree of facial numbness. Preoperative measurement of MC size can be used to guide the intraoperative balloon volume and to predict the patient’s prognosis.

KEY WORDS: Trigeminal neuralgia, percutaneous balloon compression, Meckel’s cave, magnetic resonance imaging