Predicting balloon shape in percutaneous microcompression : an observational comparative analysis of Meckel's cave imaging and balloon morphology.

Achieving a pear-shaped balloon holds pivotal significance in the context of successful percutaneous microcompression procedures for trigeminal neuralgia. However, inflated balloons may assume various configurations, whether it is inserted into Meckel's cave or not. The absence of an objective evaluation metric has become apparent. To investigate the relationship between the morphology of Meckel's Cave and the balloon used in percutaneous microcompression for trigeminal neuralgia and establish objective criteria for assessing balloon shape in percutaneous microcompression procedures. This retrospective study included 58 consecutive patients with primary trigeminal neuralgia. Data included demographic, clinical outcomes, and morphological features of Meckel's cave and the balloon obtained from MRI and Dyna-CT imaging. MRI of Meckel's cave and Dyna-CT of intraoperative balloon were modeled, and the morphological characteristics and correlation were analyzed. The reconstructed balloon presented a fuller morphology expanding outward and upward on the basis of Meckel's cave. The projected area of balloon was strongly positively correlated with the projected area of Meckel's cave. The Pearson correlation coefficients were 0.812 (P<0.001) for axial view, 0.898 (P<0.001) for sagittal view and 0.813 (P<0.001) for coronal view. Similarity analysis showed that the sagittal projection image of Meckel's cave and that of the balloon had good similarity. This study reveals that the balloon in percutaneous microcompression essentially represents an expanded morphology of Meckel's cave, extending outward and upward. There is a strong positive correlation between the volume and projected area of the balloon and that of Meckel's cave. Notably, the sagittal projection image of Meckel's cave serves as a reliable predictor of the intraoperative balloon shape. This method has a certain generalizability and can help providing objective criteria for judging balloon shape during percutaneous microcompression procedures.

A retrospective study to examine the association of different pear-shaped balloons with efficacy and postoperative complications in percutaneous balloon compression for trigeminal neuralgia.

Percutaneous balloon compression is a safe and effective therapeutic modality for trigeminal neuralgia. It is widely recognized that the pear-shaped balloon is the key to the success of the procedure. This study aimed to analyze the effect of different pear-shaped balloons on the duration of the treatment outcome. In addition, the relationship between individual variables and the duration and severity of complications was analyzed. The clinical data and intraoperative radiographs of 132 patients with trigeminal neuralgia were reviewed. We classify pear-shaped balloons into type A, type B, and type C balloons depending on the size of their heads. The collected variables were correlated with prognosis by univariate and multivariate analyses. The efficiency of the procedure was 96.9%. There was no significant difference in pain relief rates between the different pear-shaped balloons. Median pain-free survival time was longer for type B and C balloons, which were significantly different from type A balloons. In addition, pain duration also was a risk factor for recurrence. There was no significant difference in the duration of numbness between the different types of pear-shaped balloons, but type C balloons resulted in longer-lasting masticatory muscle weakness. Duration of compression and balloon shape can also significantly influence the severity of complications. Different pear-shaped balloons have been shown to have a significant effect on the efficacy and complications of the PBC procedure, with type B balloons (head ratio: 10-20%) appearing to be the ideal pear shape. However, its clinical application remains to be validated.

The Transformation of the Balloon Shape in Percutaneous Balloon Compression for Trigeminal Neuralgia.

BACKGROUND: The pear shape of an inflated balloon is thought to be a gold standard of successful percutaneous balloon compression (PBC). However, neither how nor why it changes in that way (the anatomic basis) has not yet been fully described. AIM: In this article, we try to describe how the balloon in Meckel's cave (MC) should appear and why; and identify which shapes are good pear shapes, which shapes are not good pear shapes, and which shapes are intermediate. METHODS: Radiographs from over 150 percutaneous balloon compression (PBC) cases were thoroughly evaluated. We proposed a model of changing balloon shape in MC and 70 cases were followed up over two years, in which therapeutic effect was measured. RESULTS: We found that the balloon changed stereotypically in MC. The model that we proposed is consistent with the description of MC's structures and its' surroundings in the literature. The distinct pear (pear in MC) brought about a far better surgical result than other shapes (p < 0.01). CONCLUSION: Our study showed how and why the balloon shape changed during PBC surgery. The model provides clear guidance for PBC surgery.

Newly Shaped Intra-Aortic Balloons Improve the Performance of Counterpulsation at the Semirecumbent Position: An In Vitro Study.

The major hemodynamic benefits of intra-aortic balloon pump (IABP) counterpulsation are augmentation in diastolic aortic pressure (Paug ) during inflation, and decrease in end-diastolic aortic pressure (ΔedP) during deflation. When the patient is nursed in the semirecumbent position these benefits are diminished. Attempts to change the shape of the IAB in order to limit or prevent this deterioration have been scarce. The aim of the present study was to investigate the hemodynamic performance of six new IAB shapes, and compare it to that of a traditional cylindrical IAB. A mock circulation system, featuring an artificial left ventricle and an aortic model with 11 branches and physiological resistance and compliance, was used to test one cylindrical and six newly shaped IABs at angles 0, 10, 20, 30, and 40°. Pressure was measured continuously at the aortic root during 1:1 and 1:4 IABP support. Shape 2 was found to consistently achieve, in terms of absolute magnitude, larger ΔedP at angles than the cylindrical IAB. Although ΔedP was gradually diminished with angle, it did so to a lesser degree than the cylindrical IAB; this diminishment was only 53% (with frequency 1:1) and 40% (with frequency 1:4) of that of the cylindrical IAB, when angle increased from 0 to 40°. During inflation Shape 1 displayed a more stable behavior with increasing angle compared to the cylindrical IAB; with an increase in angle from 0 to 40°, diastolic aortic pressure augmentation dropped only by 45% (with frequency 1:1) and by 33% (with frequency 1:4) of the drop reached with the cylindrical IAB. After compensating for differences in nominal IAB volume, Shape 1 generally achieved higher Paug over most angles. Newly shaped IABs could allow for IABP therapy to become more efficient for patients nursed at the semirecumbent position. The findings promote the idea of personalized rather than generalized patient therapy for the achievement of higher IABP therapeutic efficiency, with a choice of IAB shape that prioritizes the recovery of those hemodynamic indices that are more in need of support in the unassisted circulation.

Intra-aortic balloon shape change: effects on volume displacement during inflation and deflation.

It has been observed that operating the intra-aortic balloon at an angle to the horizontal resulted in a reduction of the volume displaced toward the coronary arteries and compromised afterload reduction. Therefore, the aim of this work is to examine whether changing the current balloon shape, which has not been altered for 40 years, could compensate for the negative hemodynamic effects due to angulation. We tested two tapered balloons, increasing diameter (TID) and decreasing diameter (TDD), and compared the results with those obtained from a standard cylindrical balloon. The balloons were tested in vitro at 60 beats/min and a static pressure of 90 mm Hg. The balloons were operated at four angles (0°, 20°, 30°, 45°), and the pressure at three locations along the balloon (base, middle, and tip) was also measured. Flow rate upstream of the tip of the balloon was also measured to indicate the flow displaced toward the coronary circulation. The relative volume displaced toward (VUTVi) and suctioned away from (VUTVd) the simulated ascending aorta, during inflation and deflation, respectively, is reduced when a standard cylindrical balloon is operated at an angle to the horizontal. The TDD provided the greatest VUTVi and also produced the largest pulse pressure during deflation. Although the TID provided less VUTVi and VUTVd at smaller angles, it was not markedly affected by the change of angle. According to these results, different balloon shapes analyzed, with comparable volume to that of a cylindrical balloon, produced greater inflation and deflation benefits, at the horizontal and at a range of angles to the horizontal. Further investigations are required to optimize the shape of the tapered balloons to fit into the available physiological space.