Anatomical Study of Percutaneous Trigeminal Compressive Balloon Positioning on Merged 3-D Rotational X-Ray and Preprocedural Magnetic Resonance Imaging.

Background: Percutaneous trigeminal rhizotomy or balloon compression for trigeminal neuralgia carries a potential risk for the brainstem, the carotid artery, and the basilar artery. Objective: To detail the relation of critical neural and vascular structures to expanded balloons used for percutaneous compression of the trigeminal ganglion. Method: A retrospective analysis of preprocedural magnetic resonance imaging (MRI) and procedural X-ray-based imaging for 9 patients detailed balloon proximity to the brainstem, carotid artery, and basilar artery. Results: Balloons extended 10.96 +/- 5.54 mm (mean +/- SD) posterior to the clival line. The average distance from the balloon to the brainstem was 6.89 mm, and that to the basilar artery was 12.12 mm (range: 0-18.2). The medial edge of the balloon was an average distance of 1.39 mm from the baseline position of the carotid lumen. Conclusion: Preprocedural MRI, merged with 3-D rotational angiography suite imaging, detailed the proximity of the balloon to critical neural and vascular structures. Our study found that the standard technique for percutaneous trigeminal compression, with balloon placement at an average depth of 10.96 mm posterior to the clival line, on average, provided an additional 6.89 mm of space before the brainstem would have been encountered, demonstrating safe positioning. (C) 2018 S. Karger AG, Basel