Percutaneous microballoon compression for trigeminal neuralgia using Dyna-CT

Objective Percutaneous microballoon compression (PMC)is a well-established technique for treatment of trigeminal neuralgia (TN).However,direct puncture of the foramen ovale (FO) is sometimes difficult and there have been well-reported complications from cannulating the FO.We present the use of Dyna-CT for cannulating the FO and determining the balloon' s position and volume.Methods Dyna-CT was used to perform image reconstruction in 20 patients.The optimal working projection was generated and further fluoroscopic data was used to determine the needle's relationship to the foramen during puncture.Furthermore,the balloon position and 3-dimensional shape were verified with Dyna-CT during balloon compression.The needle position and the balloon volume were further calculated.Results Dyna-CT allows quick,safe,and easy cannulation of the FO.It provided 3-dimensional imaging which were more elaborate than the classic pear shape's imaging for determining correct positioning.The angle of introducing cannula ranged from 15.17°-35.48°rotation to the midline with an average of 25.28°and 37.46°-53.18°angulations to the Reid line with an average of 46.09°.The volume of the inflated balloon ranged from 568.2 mm3to 891.4 mm3 with an average of 766.1 mm3.All the patients were pain free after PMC.2 patients had resolvable masseter weakness and fine touch loss.No recurrent of TN when followed up.Conclusions Dyna-CT demonstrated three distinct advantages over the standard technique:Firstly,the FO can be better visualized independent of the patient's position.Secondly,needle correction or insertion can be performed much easier because of the direct fluoroscopic control.Thirdly,the needle position,balloon position,balloon configuration,and the volume of the inflated balloon is more reliably determined than with the submental projection.The use of dyna-CT could decrease the incidence of complications reported with the standard fluoroscopic technique. Key words: Trigeminal neuralgia;  Microballoon compression ;  Dyna-CT