[Correlation between balloon volume and Meckel's cave size and its influence of percutaneous microballoon compression...

Objective: To investigate the correlation between balloon volume and Meckel's cave size during percutaneous puncture microballoon compression (PMC) for trigeminal neuralgia and the influence of the compression coefficient (the ratio of balloon volume/Meckel's cave size) on the prognosis. Methods: Seventy-two patients (28 males and 44 females) aged (62±11) years who underwent PMC under general anesthesia for trigeminal neuralgia in the First Affiliated Hospital of Zhengzhou University from February 2018 to October 2020 were retrospectively collected. All patients underwent preoperative cranial magnetic resonance imaging (MRI) to measure Meckel's cave size, intraoperative balloon volume was recorded, and the compression coefficient was calculated. Follow-up visits were performed preoperatively (T₀) and 1 d (T₁), 1 month (T₂), 3 months (T₃), and 6 months (T₄) postoperatively, either in the outpatient clinic or by telephone, and the Barrow Neurological Institute pain scale (BNI-P) score, the Barrow Neurological Institute facial numbness (BNI-N) score and the occurrence of complications were recorded and compared at each time point. Patients were divided into 3 groups according to different prognoses: patients in group A (n=48) were with no recurrence of pain and mild facial numbness, patients in group B (n=19) were with no recurrence of pain but severe facial numbness, while those in group C (n=5) had recurrence of pain. The differences in balloon volume, Meckel's cave size, and compression coefficient were compared among the three groups, and the correlation between balloon volume and Meckel's cave size in each group was analyzed by Pearson correlation. Results: The effective rate of PMC for trigeminal neuralgia was 93.1% (67/72). At time points from T₀ to T₄, patients had BNI-P scores [M (Q₁, Q₃)] of 4.5 (4.0, 5.0), 1.0 (1.0, 1.0), 1.0 (1.0, 1.0), 1.0 (1.0, 1.0) and 1.0 (1.0, 1.0), and BNI-N scores [M (Q₁, Q₃)] of 1.0 (1.0, 1.0), 4.0 (3.0, 4.0), 3.0 (3.0, 4.0), 3.0 (2.0, 4.0) and 2.0 (2.0, 3.0), respectively. Compared with those at T₀, patients had lower BNI-P scores and higher BNI-N scores from T₁ to T₄ (all P<0.05). In all patients, group A, group B, and group C, the balloon volume was (0.65±0.15), (0.67±0.15), (0.59±0.15) and (0.67±0.17) cm³, respectively, with no statistically significant difference (P>0.05), while the Meckel's cave size was (0.42±0.12), (0.44±0.11), (0.32±0.07), and (0.57±0.11) cm³, with a statistically significant difference (P<0.001). The balloon volumes and Meckel's cave sizes were all linearly and positively correlated (r=0.852, 0.924, 0.937 and 0.969, all P<0.05). The compression coefficient in group A, B and C was (1.54±0.14), (1.84±0.18) and (1.18±0.10), respectively, with a statistically significant difference (P<0.001). There were no serious intraoperative complications such as death, diplopia, arteriovenous fistula, cerebrospinal fluid leak, and subarachnoid hemorrhage. Conclusions: Intraoperative balloon volume during PMC for trigeminal neuralgia is linearly and positively correlated with the volume of the patient's Meckel's cave. The compression coefficient varies among patients with different prognoses and the compression coefficient may be a factor affecting the patient's prognosis.