- Email: [email protected]
Endoscopic Assisted Approaches to the Craniovertebral Junction: Lateral versus Ventral
Perspectives Commentary on: Endoscopic-Assisted Lateral Transatlantal Approach to Craniovertebral Junction by Martins et al. pp. 351-358.
Theodore H. Schwartz, M.D. Professor of Neurosurgery Departments of Neurological Surgery, Neurology, Neuroscience and Otolaryngology Weill Cornell Medical College New York Presbyterian Hospital
Endoscopic Assisted Approaches to the Craniovertebral Junction: Lateral versus Ventral Yaron A. Moshel and Theodore H. Schwartz
V
arious surgical approaches to the ventral skull base have evolved over the years and continue to develop with the introduction of new technologies. The article by Martins et al. describes an addition to the existing surgical repertoire with the added utility of incorporating an endoscope into an open surgical procedure. In an elegant series of anatomic dissections, they have shown that the endoscope improves the ability to visualize the odontoid process, ventral spinal dura, and contralateral atlantooccipital joints during the extreme lateral transatlas approach to the craniovertebral junction (CVJ). They point out that, in particular, an angled endoscopic view can be of great value when addressing ventral pathology and pathology that crosses the midline. The microscopic view of this region through an extreme lateral approach can be limited, forcing the surgeon to operate in an ergonomically difficult position and potentially achieving suboptimal results. More neurosurgeons are creatively incorporating the endoscope into their open surgical practice as they become increasingly comfortable with endoscopy (14, 27). Prior reports have shown the value of the endoscope during open surgery as an adjunct to the microscope for inspection of the suprasellar cistern after transcranial resection of a craniopharyngioma (6, 18), inspection of the trigeminal or facial nerve during a microvascular decompression (4, 11, 29, 31), inspection of the pineal region and posterior third ventricle during a supracerebellar infratentorial approach to pineal tumors (5, 16), and during cerebellopontine angle tumor removal (15, 21, 28, 30). No prior report has shown, however, the feasibility of endoscopic assistance specifically during lateral approaches to the CVJ, such as the subcondylar extreme lateral approach. Some controversy exists regarding the optimal surgical corridor
Key words 䡲 Basilar invagination 䡲 Craniovertebral junction 䡲 Endoscopy 䡲 Extreme lateral approach 䡲 Far lateral approach 䡲 Skull base 䡲 Transnasal approach
Abbreviations and Acronyms EEA: Expanded endonasal approach CVJ: Craniovertebral junction
to address anterior CVJ pathology. Various approaches exist for the resection of the dens, including anterior and lateral approaches, each of which has potential advantages and disadvantages (2, 24, 32). The transoral-transpharyngeal approach is most commonly used to resect the dens in the treatment of basilar invagination secondary to rheumatoid arthritis, congenital abnormalities of the skull base and axis, and extradural tumors (3, 7, 17, 25). This approach is familiar to most neurosurgeons and technically straightforward with short operative times. Disadvantages of the transoral approach include operating through a contaminated surgical corridor, the need for a separate craniocervical stabilization procedure, postoperative velopharyngeal insufficiency, and the potential need for a tracheostomy. These morbidities increase further when more invasive modifications are performed, such as the transoral-transmaxillary or transoraltranslabiomandibular approach. Similar to the report by Martins et al., the transoral approach has been improved with addition of endoscopic assistance and improved further with the development of the endoscopic endonasal approach (1, 8-10, 12, 13, 19, 20, 22, 23, 26). The expanded endonasal approach (EEA) has several benefits compared with the traditional transoral approach, including improved exposure of the clivus without the need for a hard or soft palate incision (3, 7). Using the EEA, pathology along the entire rostrocaudal extent of the clivus and ventral foramen magnum and upper cervical spine can be addressed. The nasopharyngeal incision, as opposed to the oropharyngeal mucosal incision, permits earlier extubation and is less likely to become contaminated by food, saliva, and oral flora. Use of the nasopharyngeal incision enables earlier feeding of the patient after surgery with little risk of infection and postoperative swallowing dysfunction (10, 12, 19, 20, 22, 23). The dura can also be opened to address
From the Departments of Neurological Surgery, Neurology, Neuroscience and Otolaryngology, Weill Cornell Medical Center, New York, New York, USA To whom correspondence should be addressed: Theodore H. Schwartz, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2010) 74, 2/3:265-267. DOI: 10.1016/j.wneu.2010.06.038
WORLD NEUROSURGERY 74 [2/3]: 265-267, AUGUST/SEPTEMBER 2010
www.WORLDNEUROSURGERY.org
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PERSPECTIVES
intradural lesions, such as foramen magnum and clival meningiomas, epidermoid tumors, and neurenteric cysts. With new multilayered closure techniques that also incorporate a vascularized mucosal flap, cerebrospinal fluid leak for intradural lesions has been virtually eliminated. The CVJ exposure with the EEA is limited superiorly by the nasal bones and cartilaginous soft tissues of the nose and inferiorly by the hard palate and soft palate (8). The other major limitation to the endoscopic EEA to the CVJ is difficulty with obtaining lateral exposure, which is limited by the medial pterygoid plate and the eustachian tube. Other limitations of the anterior approach include the need for two procedures to achieve fixation. Although patients commonly undergo both procedures during one operative sitting, the need for a second operation is clearly a limitation. The transcondylar and transatlas approaches to the CVJ were introduced for resection of the odontoid as an alternative to transoral approaches. By approaching the CVJ through a lateral route, these approaches enable operative decompression of the CVJ in a sterile field and allow for simultaneous occipito-
REFERENCES 1. Alfieri A, Jho HD, Tschabitscher M: Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study. Acta Neurochir (Wien) 144: 219-225, 2002. 2. al-Mefty O, Borba LA, Aoki N, Angtuaco E, Pait TG: The transcondylar approach to extradural nonneoplastic lesions of the craniovertebral junction. J Neurosurg 84:1-6, 1996. 3. Apuzzo ML, Weiss MH, Heiden JS: Transoral exposure of the atlantoaxial region. Neurosurgery 3: 201-207, 1978. 4. Badr-El-Dine M, El-Garem HF, Talaat AM, Magnan J: Endoscopically assisted minimally invasive microvascular decompression of hemifacial spasm. Otol Neurotol 23:122-128, 2002. 5. Cardia A, Caroli M, Pluderi M, Arienta C, Gaini SM, Lanzino G, Tschabitscher M: Endoscope-assisted infratentorial-supracerebellar approach to the third ventricle: an anatomical study. J Neurosurg 104(6 Suppl):409-414, 2006. 6. Cheng WY, Chang CS, Shen CC, Wang YC, Sun MH, Hsieh PP: Endoscope-assisted microsurgery for treatment of a suprasellar craniopharyngioma presenting precocious puberty. Pediatr Neurosurg 34: 247-251, 2001. 7. Crockard HA, Pozo JL, Ransford AO, Stevens JM, Kendall BE, Essigman WK: Transoral decompression and posterior fusion for rheumatoid atlantoaxial subluxation. J Bone Joint Surg Br 68:350-356, 1986. 8. de Almeida JR, Zanation AM, Snyderman CH, Carrau RL, Prevedello DM, Gardner PA, Kassam AB: Defining the nasopalatine line: the limit for endonasal surgery of the spine. Laryngoscope 119:239-244, 2009.
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www.SCIENCEDIRECT.com
cervical fusion (2, 32). Martins et al. identified limitations of the approach in their clinical practice and identified the value of endoscopic assistance during the decompression to help visualize the anterior spinal dura and achieve a complete decompression. Advantages of the lateral approaches include the ability to control directly any dural tears, the sterile operating environment, and the ability to fuse during the same operation. The description of the feasibility of an approach in a cadaveric study with essentially normal CVJ anatomy is still only a first step, however. The ability to visualize an anatomic structure with an endoscope is not equivalent to the ability to manipulate and remove this structure safely. We look forward to reading future descriptions of a clinical series using the extreme lateral transatlas approach with endoscopic assistance to approach various CVJ pathologies. This study by Martins et al. will help to change the dynamics of the debate between anterior versus lateral approaches to the CVJ, both of which clearly benefit from endoscopic assistance. Ultimately, for lesions with a lateral extension, a lateral approach offers clear benefits. For truly midline pathology, the benefits are less convincing.
9. de Divitiis O, Conti A, Angileri FF, Cardali S, La Torre D, Tschabitscher M: Endoscopic transoraltransclival approach to the brainstem and surrounding cisternal space: anatomic study. Neurosurgery 54:125-130, 2004. 10. Dehdashti AR, Karabatsou K, Ganna A, Witterick I, Gentili F: Expanded endoscopic endonasal approach for treatment of clival chordomas: early results in 12 patients. Neurosurgery 63:299-307, 2008. 11. El-Garem HF, Badr-El-Dine M, Talaat AM, Magnan J: Endoscopy as a tool in minimally invasive trigeminal neuralgia surgery. Otol Neurotol 23:132135, 2002. 12. Fraser JF, Nyquist GG, Moore N, Anand VK, Schwartz TH: Endoscopic endonasal transclival resection of chordomas: operative technique, clinical outcome, and review of the literature. J Neurosurg 112:1061-1069, 2010. 13. Frempong-Boadu AK, Faunce WA, Fessler RG: Endoscopically assisted transoral-transpharyngeal approach to the craniovertebral junction. Neurosurgery 51(5 Suppl):S60-66, 2002. 14. Fries G, Perneczky A: Endoscope-assisted brain surgery. Part 2: analysis of 380 procedures. Neurosurgery 42:226-231, 1998. 15. Gerganov VM, Romansky KV, Bussarsky VA, Noutchev LT, Iliev IN: Endoscope-assisted microsurgery of large vestibular schwannomas. Minim Invasive Neurosurg 48:39-43, 2005.
18. Kadri H, Mawla AA: Endoscopy-assisted microsurgical total resection of craniopharyngioma in childhood. Minim Invasive Neurosurg 49:369-372, 2006. 19. Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL: Expanded endonasal approach: the rostrocaudal axis. Part II: posterior clinoids to the foramen magnum. Neurosurg Focus 19:E4, 2005. 20. Kassam AB, Snyderman C, Gardner P, Carrau R, Spiro R: The expanded endonasal approach: a fully endoscopic transnasal approach and resection of the odontoid process: technical case report. Neurosurgery 57(1 Suppl):E213, 2005. 21. King WA, Wackym PA: Endoscope-assisted surgery for acoustic neuromas (vestibular schwannomas): early experience using the rigid Hopkins telescope. Neurosurgery 44:1095-1100, 1999. 22. Laufer I, Greenfield JP, Anand VK, Hartl R, Schwartz TH: Endonasal endoscopic resection of the odontoid process in a nonachondroplastic dwarf with juvenile rheumatoid arthritis: feasibility of the approach and utility of the intraoperative Iso-C threedimensional navigation. Case report. J Neurosurg Spine 8:376-380, 2008. 23. Leng LZ, Anand VK, Hartl R, Schwartz TH: Endonasal endoscopic resection of an os odontoideum to decompress the cervicomedullary junction: a minimal access surgical technique. Spine (Phila Pa 1976) 34:E139-43, 2009.
16. Gore PA, Gonzalez LF, Rekate HL, Nakaji P: Endoscopic supracerebellar infratentorial approach for pineal cyst resection: technical case report. Neurosurgery 62(3 Suppl 1):108-109, 2008.
24. Matsuno A, Nakashima M, Murakami M, Nagashima T: Microsurgical excision of a retro-odontoid disc hernia via a far-lateral approach: successful treatment of a rare cause of myelopathy: case report. Neurosurgery 54:1015-1018, 2004.
17. Hadley MN, Spetzler RF, Sonntag VK: The transoral approach to the superior cervical spine: a review of 53 cases of extradural cervicomedullary compression. J Neurosurg 71:16-23, 1989.
25. Menezes AH, VanGilder JC: Transoral-transpharyngeal approach to the anterior craniocervical junction: ten-year experience with 72 patients. J Neurosurg 69:895-903, 1988.
WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2010.06.038
PERSPECTIVES
26. Nayak JV, Gardner PA, Vescan AD, Carrau RL, Kassam AB, Snyderman CH: Experience with the expanded endonasal approach for resection of the odontoid process in rheumatoid disease. Am J Rhinol 21:601-606, 2007. 27. Perneczky A, Fries G: Endoscope-assisted brain surgery. Part 1: evolution, basic concept, and current technique. Neurosurgery 42:219-224, 1998. 28. Pillai P, Sammet S, Ammirati M: Image-guided, endoscopic-assisted drilling and exposure of the whole length of the internal auditory canal and its fundus with preservation of the integrity of the labyrinth using a retrosigmoid approach: a labora-
tory investigation. Neurosurgery 65(6 Suppl):5359, 2009. 29. Rak R, Sekhar LN, Stimac D, Hechl P: Endoscope-assisted microsurgery for microvascular compression syndromes. Neurosurgery 54:876881, 2004. 30. Schroeder HW, Oertel J, Gaab MR: Endoscope-assisted microsurgical resection of epidermoid tumors of the cerebellopontine angle. J Neurosurg 101:227-232, 2004. 31. Teo C, Nakaji P, Mobbs RJ: Endoscope-assisted microvascular decompression for trigeminal neural-
WORLD NEUROSURGERY 74 [2/3]: 265-267, AUGUST/SEPTEMBER 2010
gia: technical case report. Neurosurgery 59(4 Suppl 2):ONSE489-490, 2006. 32. Ture U, Pamir MN: Extreme lateral-transatlas approach for resection of the dens of the axis. J Neurosurg 96(1 Suppl):73-82, 2002.
Citation: World Neurosurg. (2010) 74, 2/3:265-267. DOI: 10.1016/j.wneu.2010.06.038 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2010 Elsevier Inc. All rights reserved.
www.WORLDNEUROSURGERY.org
267
Theodore H. Schwartz, M.D. Professor of Neurosurgery Departments of Neurological Surgery, Neurology, Neuroscience and Otolaryngology Weill Cornell Medical College New York Presbyterian Hospital
Endoscopic Assisted Approaches to the Craniovertebral Junction: Lateral versus Ventral Yaron A. Moshel and Theodore H. Schwartz
V
arious surgical approaches to the ventral skull base have evolved over the years and continue to develop with the introduction of new technologies. The article by Martins et al. describes an addition to the existing surgical repertoire with the added utility of incorporating an endoscope into an open surgical procedure. In an elegant series of anatomic dissections, they have shown that the endoscope improves the ability to visualize the odontoid process, ventral spinal dura, and contralateral atlantooccipital joints during the extreme lateral transatlas approach to the craniovertebral junction (CVJ). They point out that, in particular, an angled endoscopic view can be of great value when addressing ventral pathology and pathology that crosses the midline. The microscopic view of this region through an extreme lateral approach can be limited, forcing the surgeon to operate in an ergonomically difficult position and potentially achieving suboptimal results. More neurosurgeons are creatively incorporating the endoscope into their open surgical practice as they become increasingly comfortable with endoscopy (14, 27). Prior reports have shown the value of the endoscope during open surgery as an adjunct to the microscope for inspection of the suprasellar cistern after transcranial resection of a craniopharyngioma (6, 18), inspection of the trigeminal or facial nerve during a microvascular decompression (4, 11, 29, 31), inspection of the pineal region and posterior third ventricle during a supracerebellar infratentorial approach to pineal tumors (5, 16), and during cerebellopontine angle tumor removal (15, 21, 28, 30). No prior report has shown, however, the feasibility of endoscopic assistance specifically during lateral approaches to the CVJ, such as the subcondylar extreme lateral approach. Some controversy exists regarding the optimal surgical corridor
Key words 䡲 Basilar invagination 䡲 Craniovertebral junction 䡲 Endoscopy 䡲 Extreme lateral approach 䡲 Far lateral approach 䡲 Skull base 䡲 Transnasal approach
Abbreviations and Acronyms EEA: Expanded endonasal approach CVJ: Craniovertebral junction
to address anterior CVJ pathology. Various approaches exist for the resection of the dens, including anterior and lateral approaches, each of which has potential advantages and disadvantages (2, 24, 32). The transoral-transpharyngeal approach is most commonly used to resect the dens in the treatment of basilar invagination secondary to rheumatoid arthritis, congenital abnormalities of the skull base and axis, and extradural tumors (3, 7, 17, 25). This approach is familiar to most neurosurgeons and technically straightforward with short operative times. Disadvantages of the transoral approach include operating through a contaminated surgical corridor, the need for a separate craniocervical stabilization procedure, postoperative velopharyngeal insufficiency, and the potential need for a tracheostomy. These morbidities increase further when more invasive modifications are performed, such as the transoral-transmaxillary or transoraltranslabiomandibular approach. Similar to the report by Martins et al., the transoral approach has been improved with addition of endoscopic assistance and improved further with the development of the endoscopic endonasal approach (1, 8-10, 12, 13, 19, 20, 22, 23, 26). The expanded endonasal approach (EEA) has several benefits compared with the traditional transoral approach, including improved exposure of the clivus without the need for a hard or soft palate incision (3, 7). Using the EEA, pathology along the entire rostrocaudal extent of the clivus and ventral foramen magnum and upper cervical spine can be addressed. The nasopharyngeal incision, as opposed to the oropharyngeal mucosal incision, permits earlier extubation and is less likely to become contaminated by food, saliva, and oral flora. Use of the nasopharyngeal incision enables earlier feeding of the patient after surgery with little risk of infection and postoperative swallowing dysfunction (10, 12, 19, 20, 22, 23). The dura can also be opened to address
From the Departments of Neurological Surgery, Neurology, Neuroscience and Otolaryngology, Weill Cornell Medical Center, New York, New York, USA To whom correspondence should be addressed: Theodore H. Schwartz, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2010) 74, 2/3:265-267. DOI: 10.1016/j.wneu.2010.06.038
WORLD NEUROSURGERY 74 [2/3]: 265-267, AUGUST/SEPTEMBER 2010
www.WORLDNEUROSURGERY.org
265
PERSPECTIVES
intradural lesions, such as foramen magnum and clival meningiomas, epidermoid tumors, and neurenteric cysts. With new multilayered closure techniques that also incorporate a vascularized mucosal flap, cerebrospinal fluid leak for intradural lesions has been virtually eliminated. The CVJ exposure with the EEA is limited superiorly by the nasal bones and cartilaginous soft tissues of the nose and inferiorly by the hard palate and soft palate (8). The other major limitation to the endoscopic EEA to the CVJ is difficulty with obtaining lateral exposure, which is limited by the medial pterygoid plate and the eustachian tube. Other limitations of the anterior approach include the need for two procedures to achieve fixation. Although patients commonly undergo both procedures during one operative sitting, the need for a second operation is clearly a limitation. The transcondylar and transatlas approaches to the CVJ were introduced for resection of the odontoid as an alternative to transoral approaches. By approaching the CVJ through a lateral route, these approaches enable operative decompression of the CVJ in a sterile field and allow for simultaneous occipito-
REFERENCES 1. Alfieri A, Jho HD, Tschabitscher M: Endoscopic endonasal approach to the ventral cranio-cervical junction: anatomical study. Acta Neurochir (Wien) 144: 219-225, 2002. 2. al-Mefty O, Borba LA, Aoki N, Angtuaco E, Pait TG: The transcondylar approach to extradural nonneoplastic lesions of the craniovertebral junction. J Neurosurg 84:1-6, 1996. 3. Apuzzo ML, Weiss MH, Heiden JS: Transoral exposure of the atlantoaxial region. Neurosurgery 3: 201-207, 1978. 4. Badr-El-Dine M, El-Garem HF, Talaat AM, Magnan J: Endoscopically assisted minimally invasive microvascular decompression of hemifacial spasm. Otol Neurotol 23:122-128, 2002. 5. Cardia A, Caroli M, Pluderi M, Arienta C, Gaini SM, Lanzino G, Tschabitscher M: Endoscope-assisted infratentorial-supracerebellar approach to the third ventricle: an anatomical study. J Neurosurg 104(6 Suppl):409-414, 2006. 6. Cheng WY, Chang CS, Shen CC, Wang YC, Sun MH, Hsieh PP: Endoscope-assisted microsurgery for treatment of a suprasellar craniopharyngioma presenting precocious puberty. Pediatr Neurosurg 34: 247-251, 2001. 7. Crockard HA, Pozo JL, Ransford AO, Stevens JM, Kendall BE, Essigman WK: Transoral decompression and posterior fusion for rheumatoid atlantoaxial subluxation. J Bone Joint Surg Br 68:350-356, 1986. 8. de Almeida JR, Zanation AM, Snyderman CH, Carrau RL, Prevedello DM, Gardner PA, Kassam AB: Defining the nasopalatine line: the limit for endonasal surgery of the spine. Laryngoscope 119:239-244, 2009.
266
www.SCIENCEDIRECT.com
cervical fusion (2, 32). Martins et al. identified limitations of the approach in their clinical practice and identified the value of endoscopic assistance during the decompression to help visualize the anterior spinal dura and achieve a complete decompression. Advantages of the lateral approaches include the ability to control directly any dural tears, the sterile operating environment, and the ability to fuse during the same operation. The description of the feasibility of an approach in a cadaveric study with essentially normal CVJ anatomy is still only a first step, however. The ability to visualize an anatomic structure with an endoscope is not equivalent to the ability to manipulate and remove this structure safely. We look forward to reading future descriptions of a clinical series using the extreme lateral transatlas approach with endoscopic assistance to approach various CVJ pathologies. This study by Martins et al. will help to change the dynamics of the debate between anterior versus lateral approaches to the CVJ, both of which clearly benefit from endoscopic assistance. Ultimately, for lesions with a lateral extension, a lateral approach offers clear benefits. For truly midline pathology, the benefits are less convincing.
9. de Divitiis O, Conti A, Angileri FF, Cardali S, La Torre D, Tschabitscher M: Endoscopic transoraltransclival approach to the brainstem and surrounding cisternal space: anatomic study. Neurosurgery 54:125-130, 2004. 10. Dehdashti AR, Karabatsou K, Ganna A, Witterick I, Gentili F: Expanded endoscopic endonasal approach for treatment of clival chordomas: early results in 12 patients. Neurosurgery 63:299-307, 2008. 11. El-Garem HF, Badr-El-Dine M, Talaat AM, Magnan J: Endoscopy as a tool in minimally invasive trigeminal neuralgia surgery. Otol Neurotol 23:132135, 2002. 12. Fraser JF, Nyquist GG, Moore N, Anand VK, Schwartz TH: Endoscopic endonasal transclival resection of chordomas: operative technique, clinical outcome, and review of the literature. J Neurosurg 112:1061-1069, 2010. 13. Frempong-Boadu AK, Faunce WA, Fessler RG: Endoscopically assisted transoral-transpharyngeal approach to the craniovertebral junction. Neurosurgery 51(5 Suppl):S60-66, 2002. 14. Fries G, Perneczky A: Endoscope-assisted brain surgery. Part 2: analysis of 380 procedures. Neurosurgery 42:226-231, 1998. 15. Gerganov VM, Romansky KV, Bussarsky VA, Noutchev LT, Iliev IN: Endoscope-assisted microsurgery of large vestibular schwannomas. Minim Invasive Neurosurg 48:39-43, 2005.
18. Kadri H, Mawla AA: Endoscopy-assisted microsurgical total resection of craniopharyngioma in childhood. Minim Invasive Neurosurg 49:369-372, 2006. 19. Kassam A, Snyderman CH, Mintz A, Gardner P, Carrau RL: Expanded endonasal approach: the rostrocaudal axis. Part II: posterior clinoids to the foramen magnum. Neurosurg Focus 19:E4, 2005. 20. Kassam AB, Snyderman C, Gardner P, Carrau R, Spiro R: The expanded endonasal approach: a fully endoscopic transnasal approach and resection of the odontoid process: technical case report. Neurosurgery 57(1 Suppl):E213, 2005. 21. King WA, Wackym PA: Endoscope-assisted surgery for acoustic neuromas (vestibular schwannomas): early experience using the rigid Hopkins telescope. Neurosurgery 44:1095-1100, 1999. 22. Laufer I, Greenfield JP, Anand VK, Hartl R, Schwartz TH: Endonasal endoscopic resection of the odontoid process in a nonachondroplastic dwarf with juvenile rheumatoid arthritis: feasibility of the approach and utility of the intraoperative Iso-C threedimensional navigation. Case report. J Neurosurg Spine 8:376-380, 2008. 23. Leng LZ, Anand VK, Hartl R, Schwartz TH: Endonasal endoscopic resection of an os odontoideum to decompress the cervicomedullary junction: a minimal access surgical technique. Spine (Phila Pa 1976) 34:E139-43, 2009.
16. Gore PA, Gonzalez LF, Rekate HL, Nakaji P: Endoscopic supracerebellar infratentorial approach for pineal cyst resection: technical case report. Neurosurgery 62(3 Suppl 1):108-109, 2008.
24. Matsuno A, Nakashima M, Murakami M, Nagashima T: Microsurgical excision of a retro-odontoid disc hernia via a far-lateral approach: successful treatment of a rare cause of myelopathy: case report. Neurosurgery 54:1015-1018, 2004.
17. Hadley MN, Spetzler RF, Sonntag VK: The transoral approach to the superior cervical spine: a review of 53 cases of extradural cervicomedullary compression. J Neurosurg 71:16-23, 1989.
25. Menezes AH, VanGilder JC: Transoral-transpharyngeal approach to the anterior craniocervical junction: ten-year experience with 72 patients. J Neurosurg 69:895-903, 1988.
WORLD NEUROSURGERY, DOI:10.1016/j.wneu.2010.06.038
PERSPECTIVES
26. Nayak JV, Gardner PA, Vescan AD, Carrau RL, Kassam AB, Snyderman CH: Experience with the expanded endonasal approach for resection of the odontoid process in rheumatoid disease. Am J Rhinol 21:601-606, 2007. 27. Perneczky A, Fries G: Endoscope-assisted brain surgery. Part 1: evolution, basic concept, and current technique. Neurosurgery 42:219-224, 1998. 28. Pillai P, Sammet S, Ammirati M: Image-guided, endoscopic-assisted drilling and exposure of the whole length of the internal auditory canal and its fundus with preservation of the integrity of the labyrinth using a retrosigmoid approach: a labora-
tory investigation. Neurosurgery 65(6 Suppl):5359, 2009. 29. Rak R, Sekhar LN, Stimac D, Hechl P: Endoscope-assisted microsurgery for microvascular compression syndromes. Neurosurgery 54:876881, 2004. 30. Schroeder HW, Oertel J, Gaab MR: Endoscope-assisted microsurgical resection of epidermoid tumors of the cerebellopontine angle. J Neurosurg 101:227-232, 2004. 31. Teo C, Nakaji P, Mobbs RJ: Endoscope-assisted microvascular decompression for trigeminal neural-
WORLD NEUROSURGERY 74 [2/3]: 265-267, AUGUST/SEPTEMBER 2010
gia: technical case report. Neurosurgery 59(4 Suppl 2):ONSE489-490, 2006. 32. Ture U, Pamir MN: Extreme lateral-transatlas approach for resection of the dens of the axis. J Neurosurg 96(1 Suppl):73-82, 2002.
Citation: World Neurosurg. (2010) 74, 2/3:265-267. DOI: 10.1016/j.wneu.2010.06.038 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter © 2010 Elsevier Inc. All rights reserved.
www.WORLDNEUROSURGERY.org
267