3-D VIDEO
Anterior Transpetrosal Approach for Resection of Recurrent Skull Base Chordoma: 3-Dimensional Operative Video Joseph D. Chabot, DO, Paul Gardner, MD, Juan C. Fernandez-Miranda, MD Department of Neurosurgery, Center for Cranial Base Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
Watch now at http://bit.ly/1cgq0kw
Resection of skull base chordomas poses surgical challenges because of their anatomic proximity to critical neurovascular structures. The frequent extension and recurrence of chordomas beyond the anatomic limits of any one approach may require the full array of skull base approaches to achieve the critical goal of gross total resection. In this high-definition 3-dimensional operative video, we review the surgical anatomy and demonstrate in a step-by-step fashion the technical nuances of the extended middle fossa approach, also known as the anterior transpetrosal approach, for the resection of a recurrent chordoma located at the right petrous apex. The patient is a 42-year-old man who underwent a previous endoscopic endonasal approach for a clival chordoma followed by fractionated radiotherapy. Three years later, there was a recurrence at the most lateral aspect of the original resection, extending beyond the limits of an endoscopic endonasal approach. We performed a right temporo-zygomatic craniotomy with detachment of the zygomatic arch to maximally mobilize the temporalis muscle. An extradural middle fossa approach exposed the lateral wall of the cavernous sinus, the Meckel cave, and the petrous apex. Further mobilization of V3 was accomplished by expanding the foramen ovale. Careful exposure and sectioning of the greater petrosal nerve prevented traction injury to the facial nerve and allowed visualization of the petrous carotid artery. Tumor, involved bone, and outer dura were completely removed. The patient was discharged on postoperative day 3 without any complications. Lumbar drain placement, proper anesthetic management, and gentle surgical technique are key to preventing temporal lobe retraction damage. The 3-D video can be viewed at http://bit.ly/1cgq0kw or to view on a mobile device, scan this QR Code to link to an anaglyph (red/green) version of this 3-D video.
COMMENTS
T
his is a great demonstration of a standard anterior petrousectomy to resect a recurrent chordoma from the petrous apex. The version I viewed requires red/blue 3-dimensional glasses, and with this, the quality of the video is very good and expertly narrated. I would only concur that, for the lesion presented, this is an excellent surgical approach that allows wide, safe resection of the bone of the petrous apex. For chordomas that expand through the petroclival synchondrosis and especially chondrosarcomas, it works extremely well. Dr Fernandez-Miranda makes several key points that I would like to emphasize. It is important to begin the elevation of the temporal dura from the middle fossa floor posteriorly and work anteriorly and medially. This will help identify the landmarks and reduce (but not eliminate) the risk to the greater superficial petrosal nerve. To elevate the dura off V2 and V3, however, it is often most helpful to work from anterior to posterior. As noted in the video, this almost always has to be done with a combination of sharp and blunt dissection, and the venous bleeding can be quite annoying but is easily controlled with hemostatic agents. As demonstrated, I also feel it is important to enlarge foramen spinosum to ensure control of middle meningeal artery and to enlarge foramen rotundum and ovale to help mobilize V3 and take the traction off the gasserian ganglion to better expose the petrous apex for drilling. I also find that it is very helpful to completely remove the bone over the medial petrous carotid canal. It seems somewhat counterintuitive in that it might put the internal carotid artery at risk but is necessary to maximize the exposure. Often, it is necessary to sacrifice the greater superficial petrosal nerve, and most patients tolerate this very well. Finally, the viewer should note that the surgeons are using a cutting burr, diamond burr, and ultrasonic bone remover to maximize efficiency and safety. Once again, this 3-dimensional video with excellent narration will prove helpful to anyone undertaking an anterior petrousectomy approach. Michael J. Link Rochester, Minnesota
Disclosures Dr Gardner is a consultant for Integra LifeSciences. The other authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
464 | VOLUME 11 | NUMBER 3 | SEPTEMBER 2015
C
habot and colleagues have submitted a 3-dimensional video detailing a well-described if infrequently used approach to the petrous apex. The video and narrative are well done and highlight many of the critical nuances of the approach. In particular, the authors
www.operativeneurosurgery-online.com
Copyright © Congress of Neurological Surgeons. Unauthorized reproduction of this article is prohibited
RESECTION OF RECURRENT CHORDOMAS
emphasize the importance of beginning the elevation of the middle fossa dura posteriorly and working anteriorly and medially to avoid unintentional avulsion of the greater superficial petrosal nerve. After this initial dissection, I have found it most effective to elevate the dura off V2 and V3 using a combination of sharp and blunt dissection from anterior to posterior. As the authors note, the surgeon should expect venous bleeding, which is manageable with hemostatic agents. They also importantly emphasize the importance of gaining control of the middle meningeal artery and of mobilizing V3 and the gausserian ganglion to improve access to the petrous apex. Again, congratulations and thanks to the authors for this valuable video. Sunit Das Toronto, Canada
OPERATIVE NEUROSURGERY
T
he authors have provided an excellent 3-dimensional video illustration of an anterior petrousectomy. The choice of approach is appropriate for the pathology described. The audio, video, and narration are of high quality. Anterior petrousectomy is an important option in cases in which pathology exists between the standard corridors of approach in the anterior mesial posterior fossa. The technical nuances of the approach, the need for sharp dissection to maintain the corridor, good brain relaxation, careful petrous drilling, and the limitations of the approach have been emphasized. The authors have added a section describing the potential risks of the approach that should be reviewed before surgery with the patient. Richard W. Byrne Chicago, Illinois
VOLUME 11 | NUMBER 3 | SEPTEMBER 2015 | 465
Copyright © Congress of Neurological Surgeons. Unauthorized reproduction of this article is prohibited
Anterior Transpetrosal Approach for Resection of Recurrent Skull Base Chordoma: 3-Dimensional Operative Video Joseph D. Chabot, DO, Paul Gardner, MD, Juan C. Fernandez-Miranda, MD Department of Neurosurgery, Center for Cranial Base Surgery, University of Pittsburgh Medical Center, Pittsburgh, Pennsylvania
Watch now at http://bit.ly/1cgq0kw
Resection of skull base chordomas poses surgical challenges because of their anatomic proximity to critical neurovascular structures. The frequent extension and recurrence of chordomas beyond the anatomic limits of any one approach may require the full array of skull base approaches to achieve the critical goal of gross total resection. In this high-definition 3-dimensional operative video, we review the surgical anatomy and demonstrate in a step-by-step fashion the technical nuances of the extended middle fossa approach, also known as the anterior transpetrosal approach, for the resection of a recurrent chordoma located at the right petrous apex. The patient is a 42-year-old man who underwent a previous endoscopic endonasal approach for a clival chordoma followed by fractionated radiotherapy. Three years later, there was a recurrence at the most lateral aspect of the original resection, extending beyond the limits of an endoscopic endonasal approach. We performed a right temporo-zygomatic craniotomy with detachment of the zygomatic arch to maximally mobilize the temporalis muscle. An extradural middle fossa approach exposed the lateral wall of the cavernous sinus, the Meckel cave, and the petrous apex. Further mobilization of V3 was accomplished by expanding the foramen ovale. Careful exposure and sectioning of the greater petrosal nerve prevented traction injury to the facial nerve and allowed visualization of the petrous carotid artery. Tumor, involved bone, and outer dura were completely removed. The patient was discharged on postoperative day 3 without any complications. Lumbar drain placement, proper anesthetic management, and gentle surgical technique are key to preventing temporal lobe retraction damage. The 3-D video can be viewed at http://bit.ly/1cgq0kw or to view on a mobile device, scan this QR Code to link to an anaglyph (red/green) version of this 3-D video.
COMMENTS
T
his is a great demonstration of a standard anterior petrousectomy to resect a recurrent chordoma from the petrous apex. The version I viewed requires red/blue 3-dimensional glasses, and with this, the quality of the video is very good and expertly narrated. I would only concur that, for the lesion presented, this is an excellent surgical approach that allows wide, safe resection of the bone of the petrous apex. For chordomas that expand through the petroclival synchondrosis and especially chondrosarcomas, it works extremely well. Dr Fernandez-Miranda makes several key points that I would like to emphasize. It is important to begin the elevation of the temporal dura from the middle fossa floor posteriorly and work anteriorly and medially. This will help identify the landmarks and reduce (but not eliminate) the risk to the greater superficial petrosal nerve. To elevate the dura off V2 and V3, however, it is often most helpful to work from anterior to posterior. As noted in the video, this almost always has to be done with a combination of sharp and blunt dissection, and the venous bleeding can be quite annoying but is easily controlled with hemostatic agents. As demonstrated, I also feel it is important to enlarge foramen spinosum to ensure control of middle meningeal artery and to enlarge foramen rotundum and ovale to help mobilize V3 and take the traction off the gasserian ganglion to better expose the petrous apex for drilling. I also find that it is very helpful to completely remove the bone over the medial petrous carotid canal. It seems somewhat counterintuitive in that it might put the internal carotid artery at risk but is necessary to maximize the exposure. Often, it is necessary to sacrifice the greater superficial petrosal nerve, and most patients tolerate this very well. Finally, the viewer should note that the surgeons are using a cutting burr, diamond burr, and ultrasonic bone remover to maximize efficiency and safety. Once again, this 3-dimensional video with excellent narration will prove helpful to anyone undertaking an anterior petrousectomy approach. Michael J. Link Rochester, Minnesota
Disclosures Dr Gardner is a consultant for Integra LifeSciences. The other authors have no personal, financial, or institutional interest in any of the drugs, materials, or devices described in this article.
464 | VOLUME 11 | NUMBER 3 | SEPTEMBER 2015
C
habot and colleagues have submitted a 3-dimensional video detailing a well-described if infrequently used approach to the petrous apex. The video and narrative are well done and highlight many of the critical nuances of the approach. In particular, the authors
www.operativeneurosurgery-online.com
Copyright © Congress of Neurological Surgeons. Unauthorized reproduction of this article is prohibited
RESECTION OF RECURRENT CHORDOMAS
emphasize the importance of beginning the elevation of the middle fossa dura posteriorly and working anteriorly and medially to avoid unintentional avulsion of the greater superficial petrosal nerve. After this initial dissection, I have found it most effective to elevate the dura off V2 and V3 using a combination of sharp and blunt dissection from anterior to posterior. As the authors note, the surgeon should expect venous bleeding, which is manageable with hemostatic agents. They also importantly emphasize the importance of gaining control of the middle meningeal artery and of mobilizing V3 and the gausserian ganglion to improve access to the petrous apex. Again, congratulations and thanks to the authors for this valuable video. Sunit Das Toronto, Canada
OPERATIVE NEUROSURGERY
T
he authors have provided an excellent 3-dimensional video illustration of an anterior petrousectomy. The choice of approach is appropriate for the pathology described. The audio, video, and narration are of high quality. Anterior petrousectomy is an important option in cases in which pathology exists between the standard corridors of approach in the anterior mesial posterior fossa. The technical nuances of the approach, the need for sharp dissection to maintain the corridor, good brain relaxation, careful petrous drilling, and the limitations of the approach have been emphasized. The authors have added a section describing the potential risks of the approach that should be reviewed before surgery with the patient. Richard W. Byrne Chicago, Illinois
VOLUME 11 | NUMBER 3 | SEPTEMBER 2015 | 465
Copyright © Congress of Neurological Surgeons. Unauthorized reproduction of this article is prohibited
