Optimal duration of percutaneous microballoon compression for treatment of trigeminal nerve injury

Abstract

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 this study, percutaneous microballoon compression was performed on the rabbit trigeminal ganglion at a mean inflation pressure of 1,005 ± 150 mmHg for 2 or 5 minutes. At 1, 7 and 14 days 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. Immunohistochemical staining revealed that vascular endothelial growth factor expression in the ganglion cells and axons was significantly increased 7 days after trigeminal ganglion compression, however, the changes were similar after 2-minute compression and 5-minute compression. The upregulated expression of vascular endothelial growth factor in the ganglion cells after percutaneous microballoon compression can promote the repair of the injured nerve. These findings suggest that long-term compression is ideal for patients with recurrent trigeminal neuralgia.

Advances in diagnosis and treatment of trigeminal neuralgia

“…There are no standardized criteria concerning the compression time and the compression pressure. While experimental animal models suggest that a long compression time is associated with better outcome,89 these data are not confirmed in the clinical setting where there are consistent data that a longer compression time does not affect the pain relief and only increase the complication rate 86,90,91. Moreover, higher balloon pressures have been associated with higher rates of dysesthesia,severe numbness, and masseter weakness 92.…”

An experimental animal model for percutaneous procedures used in trigeminal neuralgia

“…Rabbits seem to be the most appropriate animals for percutaneous procedures. The advantages here are obvious: (1) rabbits are frequently used in experimental research; (2) their cost for experimental research is relatively low; (3) they have an adequately sized FOs; (4) harvesting their fairly large trigeminal nerves is easily carried out; (5) their use for experimental research is not prohibited by law in most European countries; (6) dropout rates in former studies were acceptable [ 12 , 16 ].…”

“…2 catheter to a minimal balloon length of 5 mm, its large size was not optimal for BC in rabbits. All three previously reported BC experiments [ 3 , 12 , 16 ] used Fogarty® no. 2 embolectomy catheters with tip lengths larger than the TCI.…”

“…2 . Nevertheless comparable compression pressures between 829 and 1179 mmHg in NWR [ 12 , 16 ] and 1140–1216 mmHg in humans [ 2 ] seem feasible.…”

“…Therefore, dogs were used only once to reproduce GR and TC, while New Zealand white rabbits (NWR) were used in three experimental studies for BC. Noteworthily, histological findings have been partly contradictory and a standardization of the experiments is still needed [ 3 , 8 , 11 , 12 , 16 ].…”