Percutaneous trigeminal nerve radiofrequency rhizotomy guided by computerized tomography with three-dimensional image reconstruction.

BACKGROUND: Percutaneous radiofrequency trigeminal rhizotomy offers high rates of complete pain relief for classic idiopathic trigeminal neuralgia. When performed under fluoroscopy, it may cause anxiety for an inexperienced neurosurgeon owing to lack of familiarity with the regional anatomy, lack of reliable landmarks on fluoroscopy, and perceived risks associated with inadvertent puncture of neurovascular structures near the foramen ovale. The purpose of this study is to describe a new procedure to maximize patient security and shorten operative time.

METHODS: From January 2006 to May 2009, 79 patients with trigeminal neuralgia underwent computerized tomography (CT)-guided percutaneous radiofrequency trigeminal rhizotomy under local anesthesia at Chang Gung Memorial Hospital. These patients included 22 men and 57 women, whose ages ranged from 36 to 88 years. The authors analyzed the use of CT with three-dimensional image reconstruction for the guidance of rhizotomy needle placement to determine possible difficulties during surgery and to predict the outcome of surgery.

RESULTS: The surgical outcome of CT-guided trigeminal rhizotomy was good in 63 (80%, 95% confidence interval [CI] 69.2-88.0%) of the 79 patients with more than 90% (95% CI 87.5-93.7%) pain relief. The outcomes did not differ from those of the fluoroscopy-guided procedures. However, the median time for adequate rhizotomy needle placement in the foramen ovale was reduced in the CT-guided compared with that in fluoroscopy-guided procedure (14 minutes and 40 minutes, respectively; p < 0.001) and the intra-operative discomfort of the patients was also decreased. There were no intra-operative failures.

CONCLUSION: For percutaneous trigeminal rhizotomy, three-dimensional image reconstruction provides for precise placement of the rhizotomy needle in a safe and timely manner, which improves patient comfort and shortens operative time.