Optimal duration of percutaneous microballoon compression for trigeminal nerve injury
Percutaneous microballoon compression of the trigeminal ganglion is a brand new operative technique for the treatment of trigeminal neuralgia. However, it is unclear how the procedure mediates pain relief, and there are no standardized criteria, such as compression pressure, compression time or balloon shape, for the procedure. In particular, the links between compression duration and postoperative complications and pain recurrence are still under debate. An extended duration of compression would cause irreversible injury and drastic demyelination, and paresthesia and numbness with discomfort would ensue.
In comparison, a short compression time may reduce postoperative complications. However, the rate of pain relief diminishes and the recurrence rate elevates. This may require a second operation and increase psychological and economic burdens on the patient. However, it remains a challenge to define optimal compression time, guarantee operative success, and reduce the complication rate and X-ray exposure.
In the two-minute compression group at seven days, large-diameter myelinated nerve axons were swollen, disrupted and demyelinated, and fragmentation of myelin and formation of digestion chambers were evident (transmission electron microscope, ?- 3,000).
Image credit: Neural Regeneration Research
Dr. Fuyong Li and co-workers from Shengjing Hospital, China Medical University in China established an animal model of trigeminal neuralgia using percutaneous microballoon compression on the trigeminal ganglion, with the aim of observing changes in the trigeminal ganglion and the demyelination of myelinated nerve fibers under a compression pressure of 1,005 ± 150 mmHg for 2 or 5 minutes.
After percutaneous microballoon compression, the large-diameter myelinated nerves displayed axonal swelling, rupture and demyelination under the electron microscope. Fragmentation of myelin and formation of digestion chambers were more evident after 5 minutes of compression. Image analyzer results showed that the diameter of trigeminal ganglion cells remained unaltered after compression.
These experimental findings indicate that a 2-minute period of compression can suppress pain transduction, but long-term compression is ideal for patients with recurrent trigeminal neuralgia.
The relevant paper has been published in Neural Regeneration Research (Vol. 9, No. 2, 2014).