Perspectives Commentary on: Which Routes for Petroclival Tumors? A Comparison Between the Anterior Expanded Endoscopic Endonasal Approach and Lateral or Posterior Routes by Jacquesson et al. World Neurosurg 83:929-936, 2015
The Expanded Endoscopic Endonasal Approach to Petroclival Lesions: A Useful Adjunct to Traditional Skull Base Approaches Ernest Wright and Robert F. Spetzler
P
etroclival lesions are a formidable challenge given their location in the skull base and intimate relationships with vital neurovascular structures. Preoperative planning is critical to successful surgery, as the key to successful resection of any skull base lesion is a careful choice of a surgical approach that maximizes visualization and working angles, while preserving critical structures. To this end, the initial consideration in the decision-making algorithm for treating these patients is to determine the extent of the lesion in the rostral-caudal dimension along the clivus and the long axis of the tumor. Additional considerations include baseline neurologic deficits. Although preservation of function should always be an objective, in patients for whom function is already compromised to a substantial degree, a more aggressive approach sacrificing such function may be a worthwhile tradeoff to allow for maximal resection.
skeletonizing the semicircular canals and provides a relatively narrow corridor but preserves hearing function. The translabyrinthine approach sacrifices the semicircular canals, offering better visualization and working angles at the expense of hearing function. Lastly, the transcochlear approach is the most radical of the transpetrosal approaches, involving removal of the cochlea to provide a generous exposure while sacrificing hearing and facial nerve function. However, a limitation of these lateral approaches is the exposure of the contralateral clivus. Although it is not mentioned in the article by Jacquesson et al. in a paper recently published in WORLD NEUROSURGERY, the expanded endoscopic endonasal approach (EEEA) can readily be used to address the midline and both lateral faces of the clivus.
For lesions of the petrous apex or upper clivus, the Kawase (anterior petrosectomy) and orbitozygomatic approaches offer the best surgical corridor. Although the Kawase approach has traditionally been the workhorse for resecting upper clival lesions, we have found the orbitozygomatic approach to offer the benefit of minimal brain retraction and consequently decreased postoperative morbidity (1, 2).
Lesions of the lower third of the clivus are best resected via a farlateral approach because this offers the best visualization ranging from the lower clivus to the foramen magnum and beyond to the upper cervical region. Endonasal approaches are useful here as well because they provide direct access to the midline of the inferior third of the clivus. The lateral exposure of the foramen magnum, occiput-C1 joint, and hypoglossal canal also are accessible via an EEEA but are constrained by the eustachian tube and internal carotid artery.
Lesions of the middle third of the clivus are best resected from a transpetrosal approach. We generally think of 3 options for performing a petrosectomy: the retrolabyrinthine, translabyrinthine, and transcochlear approaches. These options are listed in order of increasing visualization, at the expense of sacrificing cranial nerve function. The retrolabyrinthine approach involves
When it comes to approaching large lesions that span the clival region and may extend beyond it, we have found that it is best to combine these individual approaches to provide access to the entire lesion. For example, combining a petrosectomy and a suboccipital craniectomy with division of the tentorium offers an expansive view of the posterior and middle fossae—this would
Key words Endonasal - Endoscopy - Skull base - Petroclival - Petrosectomy - Petrous apex -
224
Abbreviations and Acronyms EEEA: Expanded endoscopic endonasal approach
www.SCIENCEDIRECT.com
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA To whom correspondence should be addressed: Robert F. Spetzler, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 2:224-225. http://dx.doi.org/10.1016/j.wneu.2015.04.010
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.04.010
PERSPECTIVES
be impossible with any previously described single approach. This combined approach can be combined further with a farlateral approach to yield even more access caudally down to and beyond the foramen magnum. The article by Jacquesson et al. is a thoughtful and balanced review of the anatomic capabilities and limitations of the EEEA to petroclival lesions. However, the authors unnecessarily limit the indications of the EEEA. In experienced hands, this approach can be used more broadly. For example, midline intradural clival lesions can be addressed from an endonasal approach. Dural repair
REFERENCES 1. Chang SW, Wu A, Gore P, Beres E, Porter RW, Preul MC, Spetzler RF, Bambakidis NC: Quantitative comparison of Kawaseʼs approach versus the retrosigmoid approach: implications for tumors involving both middle and posterior fossae. Neurosurgery 64:ons44-ons51; discussion ons51-42 2009.
techniques have advanced such that clival defects can be repaired with vascularized flaps. The chief strengths of the EEEA relative to the open approaches described earlier are that the EEEA provides bilateral clival access, does not require brain retraction, and creates a direct anterior-posterior trajectory. In conclusion, the EEEA is a useful independent or adjunctive procedure. The limitation of EEEA to extradural midline lesions as proposed by Jacquesson et al. is unnecessary and does not encourage neurosurgeons to take advantage of the full strengths of the EEEA.
2. Little AS, Jittapiromsak P, Crawford NR, Deshmukh P, Preul MC, Spetzler RF, Bambakidis NC: Quantitative analysis of exposure of staged orbitozygomatic and retrosigmoid craniotomies for lesions of the clivus with supratentorial extension. Neurosurgery 62:ons318-ons323; discussion ons323-314 2008.
Citation: World Neurosurg. (2015) 84, 2:224-225. http://dx.doi.org/10.1016/j.wneu.2015.04.010 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
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The Expanded Endoscopic Endonasal Approach to Petroclival Lesions: A Useful Adjunct to Traditional Skull Base Approaches Ernest Wright and Robert F. Spetzler
P
etroclival lesions are a formidable challenge given their location in the skull base and intimate relationships with vital neurovascular structures. Preoperative planning is critical to successful surgery, as the key to successful resection of any skull base lesion is a careful choice of a surgical approach that maximizes visualization and working angles, while preserving critical structures. To this end, the initial consideration in the decision-making algorithm for treating these patients is to determine the extent of the lesion in the rostral-caudal dimension along the clivus and the long axis of the tumor. Additional considerations include baseline neurologic deficits. Although preservation of function should always be an objective, in patients for whom function is already compromised to a substantial degree, a more aggressive approach sacrificing such function may be a worthwhile tradeoff to allow for maximal resection.
skeletonizing the semicircular canals and provides a relatively narrow corridor but preserves hearing function. The translabyrinthine approach sacrifices the semicircular canals, offering better visualization and working angles at the expense of hearing function. Lastly, the transcochlear approach is the most radical of the transpetrosal approaches, involving removal of the cochlea to provide a generous exposure while sacrificing hearing and facial nerve function. However, a limitation of these lateral approaches is the exposure of the contralateral clivus. Although it is not mentioned in the article by Jacquesson et al. in a paper recently published in WORLD NEUROSURGERY, the expanded endoscopic endonasal approach (EEEA) can readily be used to address the midline and both lateral faces of the clivus.
For lesions of the petrous apex or upper clivus, the Kawase (anterior petrosectomy) and orbitozygomatic approaches offer the best surgical corridor. Although the Kawase approach has traditionally been the workhorse for resecting upper clival lesions, we have found the orbitozygomatic approach to offer the benefit of minimal brain retraction and consequently decreased postoperative morbidity (1, 2).
Lesions of the lower third of the clivus are best resected via a farlateral approach because this offers the best visualization ranging from the lower clivus to the foramen magnum and beyond to the upper cervical region. Endonasal approaches are useful here as well because they provide direct access to the midline of the inferior third of the clivus. The lateral exposure of the foramen magnum, occiput-C1 joint, and hypoglossal canal also are accessible via an EEEA but are constrained by the eustachian tube and internal carotid artery.
Lesions of the middle third of the clivus are best resected from a transpetrosal approach. We generally think of 3 options for performing a petrosectomy: the retrolabyrinthine, translabyrinthine, and transcochlear approaches. These options are listed in order of increasing visualization, at the expense of sacrificing cranial nerve function. The retrolabyrinthine approach involves
When it comes to approaching large lesions that span the clival region and may extend beyond it, we have found that it is best to combine these individual approaches to provide access to the entire lesion. For example, combining a petrosectomy and a suboccipital craniectomy with division of the tentorium offers an expansive view of the posterior and middle fossae—this would
Key words Endonasal - Endoscopy - Skull base - Petroclival - Petrosectomy - Petrous apex -
224
Abbreviations and Acronyms EEEA: Expanded endoscopic endonasal approach
www.SCIENCEDIRECT.com
Division of Neurological Surgery, Barrow Neurological Institute, St. Joseph’s Hospital and Medical Center, Phoenix, Arizona, USA To whom correspondence should be addressed: Robert F. Spetzler, M.D. [E-mail: [email protected]] Citation: World Neurosurg. (2015) 84, 2:224-225. http://dx.doi.org/10.1016/j.wneu.2015.04.010
WORLD NEUROSURGERY, http://dx.doi.org/10.1016/j.wneu.2015.04.010
PERSPECTIVES
be impossible with any previously described single approach. This combined approach can be combined further with a farlateral approach to yield even more access caudally down to and beyond the foramen magnum. The article by Jacquesson et al. is a thoughtful and balanced review of the anatomic capabilities and limitations of the EEEA to petroclival lesions. However, the authors unnecessarily limit the indications of the EEEA. In experienced hands, this approach can be used more broadly. For example, midline intradural clival lesions can be addressed from an endonasal approach. Dural repair
REFERENCES 1. Chang SW, Wu A, Gore P, Beres E, Porter RW, Preul MC, Spetzler RF, Bambakidis NC: Quantitative comparison of Kawaseʼs approach versus the retrosigmoid approach: implications for tumors involving both middle and posterior fossae. Neurosurgery 64:ons44-ons51; discussion ons51-42 2009.
techniques have advanced such that clival defects can be repaired with vascularized flaps. The chief strengths of the EEEA relative to the open approaches described earlier are that the EEEA provides bilateral clival access, does not require brain retraction, and creates a direct anterior-posterior trajectory. In conclusion, the EEEA is a useful independent or adjunctive procedure. The limitation of EEEA to extradural midline lesions as proposed by Jacquesson et al. is unnecessary and does not encourage neurosurgeons to take advantage of the full strengths of the EEEA.
2. Little AS, Jittapiromsak P, Crawford NR, Deshmukh P, Preul MC, Spetzler RF, Bambakidis NC: Quantitative analysis of exposure of staged orbitozygomatic and retrosigmoid craniotomies for lesions of the clivus with supratentorial extension. Neurosurgery 62:ons318-ons323; discussion ons323-314 2008.
Citation: World Neurosurg. (2015) 84, 2:224-225. http://dx.doi.org/10.1016/j.wneu.2015.04.010 Journal homepage: www.WORLDNEUROSURGERY.org Available online: www.sciencedirect.com 1878-8750/$ - see front matter ª 2015 Elsevier Inc. All rights reserved.
ELSEVIER 360 Park Avenue South, New York, NY 10010
Subscription Customer Service 3251 Riverport Lane, Maryland Heights, MO 63043 Tel: (314) 447-8871 (International) Tel: (800) 654-2452 (US) Fax: (314) 447-8029 (US and International) Email: [email protected]
Advertising Orders and Inquiries Inquiries regarding advertising in WORLD NEUROSURGERY should be directed to: Bob Heiman RH Media LLC Office: +1-856-673-4000 Mobile: +1-856-520-9632 Fax: +1-856-673-4001 Email: [email protected] Ratecards: www.elsmediakits.com
The website for submitting an article to WORLD NEUROSURGERY, including the Guide for Authors link, can be found online at Ulysses Portal: http://ees.elsevier.com/worldneurosurgery/
WORLD NEUROSURGERY 84 [2]: 224-225, AUGUST 2015
www.WORLDNEUROSURGERY.org
225
