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Virtual reality imaging technique in percutaneous radiofrequency rhizotomy for intractable trigeminal neuralgia
Journal of Clinical Neuroscience 16 (2009) 449–451
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Technical Note
Virtual reality imaging technique in percutaneous radiofrequency rhizotomy for intractable trigeminal neuralgia Fan-Gang Meng a, Cheng-Yuan Wu b,*, Yu-Guang Liu b, Lei Liu c a
Beijing Neurosurgical Institute, BeijingTiantan Hospital, Capital Medical University, Beijing 100050, China Department of Neurosurgery, Qilu Hospital of Shandong University, No. 107 WenHua West Road, Ji’nan 250012, China c Shandong Electric Power Central Hospital, Ji’nan, China b
a r t i c l e
i n f o
Article history: Received 10 October 2007 Accepted 12 March 2008
Keywords: Trigeminal neuralgia Radiofrequency thermocoagulation Rhizotomy Virtual reality
a b s t r a c t Trigeminal neuralgia (TN) is the most common facial neuralgia, and is extremely painful. We evaluate the effectiveness of percutaneous controlled radiofrequency trigeminal rhizotomy (RFTR) assisted by a virtual reality (VR) imaging technique for idiopathic TN. A total of 2769 patients with TN underwent RFTR procedures between June 1986 and March 2007, with VR assisted guiding and electrode positioning in 26 patients from January 2006 to March 2007. A laminal basicranial CT scan (2 mm slice, 16 slices/s) was used during RFTR. The three-dimensional (3D) position of the electrode needle tip and the oval foramen can be seen clearly using this VR technique. The position and depth of the needle was adjusted according to the virtual 3D-CT scan. CT scanning was performed repeatedly until the needle tip was situated in the oval foramen. Usually, the tip of the electrode was adjusted once or twice. Acute pain relief was accomplished in the 26 patients who underwent a single RFTR procedure assisted with VR. No recurrence of pain was noted except in one patient after 16 months. There were no permanent complications or mortality. VR-assisted RFTR represents a minimally invasive, low-risk technique with a higher efficacy compared with traditional RFTR. Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction
2. Patients and methods
patients from Jan 2006 to March 2007. The average age of this group was 61 years. Severe facial pain had been present from 9 months to 8 years. Carbamazepine is the first line of treatment for TN. VR-RFTR was performed when treatment failed because of poor efficacy or severe side effects of carbamazepine treatment up to a dose of 800 mg per day or difficulty in localizing the target during standard RFTR. All the patients in this group had been evaluated preoperatively by cranial MRI or CT scans to exclude any lesion or tumor in the pontocerebellar angle, petrous apex, cavernous sinus, or cranial base. This group included patients who had failed or recurred after standard RFTR, or who required accurate targetting. Five patients had undergone trigeminal peripheral neurectomy or standard RFTR but had recurred. Generally, older patients, patients who declined microvascular decompression (MVD), or patients with contraindication to MVD, including poor general health, were selected for VR-RFTR procedure.
2.1. Patient information
2.2. Procedure
RFTR was performed in 2769 cases from June 1986 to March 2007. Of these, VR–RFTR was performed on 17 female and 9 male
We used the RFG-3GF radiofrequency instrument from the American Radionics Corporation (Jacksonville, FL, USA) or the Leksell Elekta instrument (Stockholm, Sweden). The supine position and Hartel’s technique were used. Point A was 3 cm from the angulus oris on the affected side, B was 2.5 cm from the external
For more than three decades, virtual reality (VR)-simulated environments have been used for the training of personnel. Advances in computing have made photorealistic graphical rendering and manipulation of virtual surgical substrates a reality. Thus VR is becoming more valuable in simulating operative events, training, and, during surgery.1 Percutaneous controlled radiofrequency trigeminal rhizotomy (RFTR) is one of the efficacious methods of pain relief for trigeminal neuralgia (TN). VR-assisted RFTR (VR-RFTR) provides a three-dimensional (3D) view of the oval foramen and the electrode needle tip, which allows precise localization during the treatment of TN. We performed VR-RFTR on 26 TN patients in our hospitals from January 2006 to March 2007 with good results.
* Corresponding author. Tel.: +86-531-8838 0929. E-mail address: [email protected] (C.-Y. Wu). 0967-5868/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2008.03.019
450
F.-G. Meng et al. / Journal of Clinical Neuroscience 16 (2009) 449–451
auditory meatus, and C was the homolateral pupil. AB and AC were connected. The RFTR thermistor electrode needle (No. 8 insulation electrode needle, Radionics, Burlington, MA, USA) with a 0.5 cm naked front was used for the procedure. Taking A as the entrance point, the needle point was aimed at the oval foramen, while the needle body was maintained vertically between the two lines AB and AC. The patient’s sensation of severe pain, and the ‘‘empty” feeling to the operator indicate that the needle is approaching the oval foramen. A laminal basicranial CT scan (2 mm slice and 16 slices/s) was performed on all patients. The spatial relationship between the needle tip and the oval foramen was seen clearly with the help of the VR technique. Needle position and depth were adjusted until the needle tip entered the oval foramen (<1 cm). The needle tip was usually adjusted once or twice. The tip of the RFTR thermistor electrode was 3.5 mm away from the first puncture (VR, Fig. 1), but it was guided into the oval foramen with the assistance of the VR image (Fig. 2). The impedance of the radiofrequency catheter tip was monitored to avoid complications. The impedance of trigeminal nerve rootlets was 200 ohms to 370 ohms whereas the impedance of bone was 1000 ohms. The correctly targeted branch of the trigeminal nerve was confirmed by electrical stimulation at 0.2 V to 1 V (50 Hz, 0.2 ms) before selective RFTR was performed. The RFTR procedure was performed as described by Kanpolat.2 After the furthest location of the target was confirmed by electrophysiology, we performed radiofrequency thermocoagulation of the trigeminal ganglion with the temperature set between 55°C and 75°C for 5–7 separate lesions. The preferred temperature for the initial or test lesion was 55°C and the temperature never exceeded 75°C. Each cycle lasted from 0.5 min to 1.0 min. The total lesion duration was 3.5 min to 5.0 min. The sense of pain and touch was continuously monitored with a needle stick during RFTR. The procedure was completed if adequate hypalgesia was achieved in the targeted branch and if pain could not be triggered as it had been pre-operatively.
Fig. 2. The location of the radiofrequency-trigeminal rhizotomy thermistor electrode needle tip in the oval foramen after an adjustment based on virtual reality.
All 26 patients were followed-up for 3 to 16 months. Pain recurrence and post-operative complications were noted. 3. Results The results were satisfactory and no complications occurred. Only one patient needed a second VR-RFTR for pain recurrence after 16 months. 4. Discussion
Fig. 1. Virtual reality image showing that the tip of the radiofrequency-trigeminal rhizotomy thermistor electrode needle 3.5 mm away from the oval foramen in the first pass.
RFTR and other minimally invasive therapies, including stereotactic radiosurgery, are effective for clinical syndromes characterized by paroxysmal severe pain. Among these, RFTR is popular because it is less invasive, delivers high initial pain relief rate, and has low rates of pain recurrence.3 Acute pain relief can be accomplished in 96% to 97.6% of patients.2,4 Complications and pain relapse are the major obstacles to clinical application of RFTR. These may be associated with incorrect target or needle trajectory. Although there are complications related to locating the oval foramen, such as carotid-cavernous fistula, abducens nerve palsy, blindness, meningitis, rhinorrhea, and intracerebral injury, these are very rare.5–13 The electrode should be inserted into the posterior part of the trigeminal ganglion to avoid complications. VR was introduced to RFTR to assure the accurate direction of treatment. The concept of VR, a term first coined by Jaron Lanier, recently has been considered a valuable tool in emerging paradigms of surgical training.14 We have also adopted it in the practical treatment of RFTR. It allows real-time manipulation of the multi-technique 3D-CT scans and provides a suite of segmentation and planning tools. Based on our experience, the target location, depth of the electrode tip, and the distance between the electrode tip and the oval foramen are viewed clearly with data obtained in nearly real-time, allowing for accurate adjustment. Therefore, the accuracy and success rate of RFTR can be improved. Through the use of a combina-
F.-G. Meng et al. / Journal of Clinical Neuroscience 16 (2009) 449–451
tion of VR–RFTR, impedance monitoring and stimulation, pain relief can be achieved and complications avoided. Pain was alleviated in all patients with no post-operative complications. These results were better than those achieved using transverse CT scans and neuro-navigation assisted RFTR in our group.4,15 Pain may recur early (<6 months) in 7.7% of patients.2 There is a 50% risk of pain recurrence 2 years after RFTR in other reports.16 However, pain recurred in only one patient in our group during a follow-up of 3–16 months. We conclude that accurate location guided by 3D CT VR have the potential to decrease complications and pain recurrence after RFTR.
Acknowlegments The authors thank Dr Dong-guang Wei, Center for Neuroscience, UC Davis, for reviewing and revising this manuscript.
References 1. Apuzzo ML, Liu CY. 2001: Things to come. Neurosurgery 2001;49:765–78. 2. Kanpolat Y, Savas A, Bekar A, et al. Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25year experience with 1,600 patients. Neurosurgery 2001;48:524–32; discussion 532–4. 3. Taha JM, Tew Jr JM. Comparison of surgical treatments for trigeminal neuralgia: reevaluation of radiofrequency rhizotomy. Neurosurgery 1996;38:865–71.
451
4. Wu CY, Meng FG, Xu SJ, et al. Selective percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia: report on 1860 cases. Chin Med J (Engl) 2004;117:467–70. 5. Ugur HC, Savas A, Elhan A, et al. Unanticipated complication of percutaneous radiofrequency trigeminal rhizotomy: rhinorrhea: report of three cases and a cadaver study. Neurosurgery 2004;54:1522–4; discussion 1524–6. 6. Harrigan MR, Chandler WF. Abducens nerve palsy after radiofrequency rhizolysis for trigeminal neuralgia: case report. Neurosurgery 1998;43:623–5. 7. Gocer AI, Cetinalp E, Tuna M. Fatal complication of the percutaneous radiofrequency trigeminal rhizotomy. Acta Neurochir (Wien) 1997;139:373–4. 8. James EA, Kibbler CC, Gillespie SH. Meningitis due to oral streptococci following percutaneous glycerol rhizotomy of the trigeminal ganglion. J Infect 1995;31:55–7. 9. Gokalp HZ, Kanpolat Y, Tumer B. Carotid-cavernous fistula following percutaneous trigeminal ganglion approach. Clin Neurol Neurosurg 1980;82:269–72. 10. Puca A, Meglio M, Cioni B, et al. Intracerebral injury following thermocoagulation of the trigeminal ganglion. Surg Neurol 1992;38:280–2. 11. Egan RA, Pless M, Shults WT. Monocular blindness as a complication of trigeminal radiofrequency rhizotomy. Am J Ophthalmol 2001;131:237–40. 12. Feiler V, Godel V, Lazar M. Sudden blindness after thermocoagulation of the trigeminal ganglion. Ann Ophthalmol 1990;22:339–40. 13. Kaplan M, Erol FS, Ozveren MF, et al. Review of complications due to foramen ovale puncture. J Clin Neurosci 2007;14:563–8. 14. Spicer MA, van Velsen M, Caffrey JP, et al. Virtual reality neurosurgery: a simulator blueprint. Neurosurgery 2004;54:783–97; discussion 797–8. 15. Yang Y, Shao Y, Wang H, et al. Neuronavigation-assisted percutaneous radiofrequency thermocoagulation therapy in trigeminal neuralgia. Clin J Pain 2007;23:159–64. 16. Tronnier VM, Rasche D, Hamer J, et al. Treatment of idiopathic trigeminal neuralgia: comparison of long-term outcome after radiofrequency rhizotomy and microvascular decompression. Neurosurgery 2001;48:1261–7; discussion 1267–8.
Contents lists available at ScienceDirect
Journal of Clinical Neuroscience journal homepage: www.elsevier.com/locate/jocn
Technical Note
Virtual reality imaging technique in percutaneous radiofrequency rhizotomy for intractable trigeminal neuralgia Fan-Gang Meng a, Cheng-Yuan Wu b,*, Yu-Guang Liu b, Lei Liu c a
Beijing Neurosurgical Institute, BeijingTiantan Hospital, Capital Medical University, Beijing 100050, China Department of Neurosurgery, Qilu Hospital of Shandong University, No. 107 WenHua West Road, Ji’nan 250012, China c Shandong Electric Power Central Hospital, Ji’nan, China b
a r t i c l e
i n f o
Article history: Received 10 October 2007 Accepted 12 March 2008
Keywords: Trigeminal neuralgia Radiofrequency thermocoagulation Rhizotomy Virtual reality
a b s t r a c t Trigeminal neuralgia (TN) is the most common facial neuralgia, and is extremely painful. We evaluate the effectiveness of percutaneous controlled radiofrequency trigeminal rhizotomy (RFTR) assisted by a virtual reality (VR) imaging technique for idiopathic TN. A total of 2769 patients with TN underwent RFTR procedures between June 1986 and March 2007, with VR assisted guiding and electrode positioning in 26 patients from January 2006 to March 2007. A laminal basicranial CT scan (2 mm slice, 16 slices/s) was used during RFTR. The three-dimensional (3D) position of the electrode needle tip and the oval foramen can be seen clearly using this VR technique. The position and depth of the needle was adjusted according to the virtual 3D-CT scan. CT scanning was performed repeatedly until the needle tip was situated in the oval foramen. Usually, the tip of the electrode was adjusted once or twice. Acute pain relief was accomplished in the 26 patients who underwent a single RFTR procedure assisted with VR. No recurrence of pain was noted except in one patient after 16 months. There were no permanent complications or mortality. VR-assisted RFTR represents a minimally invasive, low-risk technique with a higher efficacy compared with traditional RFTR. Ó 2008 Elsevier Ltd. All rights reserved.
1. Introduction
2. Patients and methods
patients from Jan 2006 to March 2007. The average age of this group was 61 years. Severe facial pain had been present from 9 months to 8 years. Carbamazepine is the first line of treatment for TN. VR-RFTR was performed when treatment failed because of poor efficacy or severe side effects of carbamazepine treatment up to a dose of 800 mg per day or difficulty in localizing the target during standard RFTR. All the patients in this group had been evaluated preoperatively by cranial MRI or CT scans to exclude any lesion or tumor in the pontocerebellar angle, petrous apex, cavernous sinus, or cranial base. This group included patients who had failed or recurred after standard RFTR, or who required accurate targetting. Five patients had undergone trigeminal peripheral neurectomy or standard RFTR but had recurred. Generally, older patients, patients who declined microvascular decompression (MVD), or patients with contraindication to MVD, including poor general health, were selected for VR-RFTR procedure.
2.1. Patient information
2.2. Procedure
RFTR was performed in 2769 cases from June 1986 to March 2007. Of these, VR–RFTR was performed on 17 female and 9 male
We used the RFG-3GF radiofrequency instrument from the American Radionics Corporation (Jacksonville, FL, USA) or the Leksell Elekta instrument (Stockholm, Sweden). The supine position and Hartel’s technique were used. Point A was 3 cm from the angulus oris on the affected side, B was 2.5 cm from the external
For more than three decades, virtual reality (VR)-simulated environments have been used for the training of personnel. Advances in computing have made photorealistic graphical rendering and manipulation of virtual surgical substrates a reality. Thus VR is becoming more valuable in simulating operative events, training, and, during surgery.1 Percutaneous controlled radiofrequency trigeminal rhizotomy (RFTR) is one of the efficacious methods of pain relief for trigeminal neuralgia (TN). VR-assisted RFTR (VR-RFTR) provides a three-dimensional (3D) view of the oval foramen and the electrode needle tip, which allows precise localization during the treatment of TN. We performed VR-RFTR on 26 TN patients in our hospitals from January 2006 to March 2007 with good results.
* Corresponding author. Tel.: +86-531-8838 0929. E-mail address: [email protected] (C.-Y. Wu). 0967-5868/$ - see front matter Ó 2008 Elsevier Ltd. All rights reserved. doi:10.1016/j.jocn.2008.03.019
450
F.-G. Meng et al. / Journal of Clinical Neuroscience 16 (2009) 449–451
auditory meatus, and C was the homolateral pupil. AB and AC were connected. The RFTR thermistor electrode needle (No. 8 insulation electrode needle, Radionics, Burlington, MA, USA) with a 0.5 cm naked front was used for the procedure. Taking A as the entrance point, the needle point was aimed at the oval foramen, while the needle body was maintained vertically between the two lines AB and AC. The patient’s sensation of severe pain, and the ‘‘empty” feeling to the operator indicate that the needle is approaching the oval foramen. A laminal basicranial CT scan (2 mm slice and 16 slices/s) was performed on all patients. The spatial relationship between the needle tip and the oval foramen was seen clearly with the help of the VR technique. Needle position and depth were adjusted until the needle tip entered the oval foramen (<1 cm). The needle tip was usually adjusted once or twice. The tip of the RFTR thermistor electrode was 3.5 mm away from the first puncture (VR, Fig. 1), but it was guided into the oval foramen with the assistance of the VR image (Fig. 2). The impedance of the radiofrequency catheter tip was monitored to avoid complications. The impedance of trigeminal nerve rootlets was 200 ohms to 370 ohms whereas the impedance of bone was 1000 ohms. The correctly targeted branch of the trigeminal nerve was confirmed by electrical stimulation at 0.2 V to 1 V (50 Hz, 0.2 ms) before selective RFTR was performed. The RFTR procedure was performed as described by Kanpolat.2 After the furthest location of the target was confirmed by electrophysiology, we performed radiofrequency thermocoagulation of the trigeminal ganglion with the temperature set between 55°C and 75°C for 5–7 separate lesions. The preferred temperature for the initial or test lesion was 55°C and the temperature never exceeded 75°C. Each cycle lasted from 0.5 min to 1.0 min. The total lesion duration was 3.5 min to 5.0 min. The sense of pain and touch was continuously monitored with a needle stick during RFTR. The procedure was completed if adequate hypalgesia was achieved in the targeted branch and if pain could not be triggered as it had been pre-operatively.
Fig. 2. The location of the radiofrequency-trigeminal rhizotomy thermistor electrode needle tip in the oval foramen after an adjustment based on virtual reality.
All 26 patients were followed-up for 3 to 16 months. Pain recurrence and post-operative complications were noted. 3. Results The results were satisfactory and no complications occurred. Only one patient needed a second VR-RFTR for pain recurrence after 16 months. 4. Discussion
Fig. 1. Virtual reality image showing that the tip of the radiofrequency-trigeminal rhizotomy thermistor electrode needle 3.5 mm away from the oval foramen in the first pass.
RFTR and other minimally invasive therapies, including stereotactic radiosurgery, are effective for clinical syndromes characterized by paroxysmal severe pain. Among these, RFTR is popular because it is less invasive, delivers high initial pain relief rate, and has low rates of pain recurrence.3 Acute pain relief can be accomplished in 96% to 97.6% of patients.2,4 Complications and pain relapse are the major obstacles to clinical application of RFTR. These may be associated with incorrect target or needle trajectory. Although there are complications related to locating the oval foramen, such as carotid-cavernous fistula, abducens nerve palsy, blindness, meningitis, rhinorrhea, and intracerebral injury, these are very rare.5–13 The electrode should be inserted into the posterior part of the trigeminal ganglion to avoid complications. VR was introduced to RFTR to assure the accurate direction of treatment. The concept of VR, a term first coined by Jaron Lanier, recently has been considered a valuable tool in emerging paradigms of surgical training.14 We have also adopted it in the practical treatment of RFTR. It allows real-time manipulation of the multi-technique 3D-CT scans and provides a suite of segmentation and planning tools. Based on our experience, the target location, depth of the electrode tip, and the distance between the electrode tip and the oval foramen are viewed clearly with data obtained in nearly real-time, allowing for accurate adjustment. Therefore, the accuracy and success rate of RFTR can be improved. Through the use of a combina-
F.-G. Meng et al. / Journal of Clinical Neuroscience 16 (2009) 449–451
tion of VR–RFTR, impedance monitoring and stimulation, pain relief can be achieved and complications avoided. Pain was alleviated in all patients with no post-operative complications. These results were better than those achieved using transverse CT scans and neuro-navigation assisted RFTR in our group.4,15 Pain may recur early (<6 months) in 7.7% of patients.2 There is a 50% risk of pain recurrence 2 years after RFTR in other reports.16 However, pain recurred in only one patient in our group during a follow-up of 3–16 months. We conclude that accurate location guided by 3D CT VR have the potential to decrease complications and pain recurrence after RFTR.
Acknowlegments The authors thank Dr Dong-guang Wei, Center for Neuroscience, UC Davis, for reviewing and revising this manuscript.
References 1. Apuzzo ML, Liu CY. 2001: Things to come. Neurosurgery 2001;49:765–78. 2. Kanpolat Y, Savas A, Bekar A, et al. Percutaneous controlled radiofrequency trigeminal rhizotomy for the treatment of idiopathic trigeminal neuralgia: 25year experience with 1,600 patients. Neurosurgery 2001;48:524–32; discussion 532–4. 3. Taha JM, Tew Jr JM. Comparison of surgical treatments for trigeminal neuralgia: reevaluation of radiofrequency rhizotomy. Neurosurgery 1996;38:865–71.
451
4. Wu CY, Meng FG, Xu SJ, et al. Selective percutaneous radiofrequency thermocoagulation in the treatment of trigeminal neuralgia: report on 1860 cases. Chin Med J (Engl) 2004;117:467–70. 5. Ugur HC, Savas A, Elhan A, et al. Unanticipated complication of percutaneous radiofrequency trigeminal rhizotomy: rhinorrhea: report of three cases and a cadaver study. Neurosurgery 2004;54:1522–4; discussion 1524–6. 6. Harrigan MR, Chandler WF. Abducens nerve palsy after radiofrequency rhizolysis for trigeminal neuralgia: case report. Neurosurgery 1998;43:623–5. 7. Gocer AI, Cetinalp E, Tuna M. Fatal complication of the percutaneous radiofrequency trigeminal rhizotomy. Acta Neurochir (Wien) 1997;139:373–4. 8. James EA, Kibbler CC, Gillespie SH. Meningitis due to oral streptococci following percutaneous glycerol rhizotomy of the trigeminal ganglion. J Infect 1995;31:55–7. 9. Gokalp HZ, Kanpolat Y, Tumer B. Carotid-cavernous fistula following percutaneous trigeminal ganglion approach. Clin Neurol Neurosurg 1980;82:269–72. 10. Puca A, Meglio M, Cioni B, et al. Intracerebral injury following thermocoagulation of the trigeminal ganglion. Surg Neurol 1992;38:280–2. 11. Egan RA, Pless M, Shults WT. Monocular blindness as a complication of trigeminal radiofrequency rhizotomy. Am J Ophthalmol 2001;131:237–40. 12. Feiler V, Godel V, Lazar M. Sudden blindness after thermocoagulation of the trigeminal ganglion. Ann Ophthalmol 1990;22:339–40. 13. Kaplan M, Erol FS, Ozveren MF, et al. Review of complications due to foramen ovale puncture. J Clin Neurosci 2007;14:563–8. 14. Spicer MA, van Velsen M, Caffrey JP, et al. Virtual reality neurosurgery: a simulator blueprint. Neurosurgery 2004;54:783–97; discussion 797–8. 15. Yang Y, Shao Y, Wang H, et al. Neuronavigation-assisted percutaneous radiofrequency thermocoagulation therapy in trigeminal neuralgia. Clin J Pain 2007;23:159–64. 16. Tronnier VM, Rasche D, Hamer J, et al. Treatment of idiopathic trigeminal neuralgia: comparison of long-term outcome after radiofrequency rhizotomy and microvascular decompression. Neurosurgery 2001;48:1261–7; discussion 1267–8.