See the corresponding article in this issue (E20).
Neurosurg Focus 37 (4):E21, 2014 ©AANS, 2014
Editorial
The endoscopic keyhole supraorbital approach Gabriel Zada, M.D. Department of Neurosurgery, University of Southern California, Los Angeles, California
In the current issue of Neurosurgical Focus, Gazzeri et al. present their experience with the endoscopic supraorbital eyebrow approach for a variety of pathological entities of the anterior skull base and parasellar region.1 The keyhole supraorbital approach has steadily become a workhorse operation for neurosurgeons who routinely treat tumors and aneurysms in these anatomical regions.2 The authors are to be acknowledged for further developing this minimally invasive approach and for routinely integrating the endoscope into their practice, which improves overall visualization and facilitates inspection around anatomical corners such as the tuberculum sellae. The authors report accessing and successfully treating a wide variety of lesions in 97 patients with an acceptable rate of morbidity, and they report very few issues related specifically to the eyebrow approach itself (e.g., frontalis nerve paresis, CSF leaks, or wound infections relating to the frontal sinus). The median hospital stay was 2.7 days, which may be one of the most important benefits offered by the keyhole supraorbital approach. For many neurosurgeons who routinely perform endoscopic and minimally invasive operations, the endoscopic keyhole supraorbital craniotomy is a natural and complementary alternative that capitalizes on much of the same optics, technology, and instrumentation as endoscopic endonasal approaches, while also maintaining many of the benefits of a traditional craniotomy (e.g., standard bipolar cautery). The decision to utilize a keyhole supraorbital approach is often made after careful consideration of alternative surgical options for accessing the anterior skull base and parasellar region, often including direct/extended endoscopic endonasal approaches and more traditional open techniques including the pterional transsylvian and bifrontal craniotomy. Ideally, the surgeon is capable of performing all of these approaches and can appropriately select and tailor any of them for a given patient scenario, as they all play useful and validated roles in the management of various skull Neurosurg Focus / Volume 37 / October 2014
base pathology. The major benefits of the supraorbital keyhole approach are the near-complete eradication of postoperative CSF leaks, minimal requirement for brain retraction, and an approach that allows direct visualization and access to the suprasellar region coursing beneath the optic chiasm in a majority of cases. Compared with the pterional transsylvian approach for suprasellar pathology, there is no need to split the sylvian fissure, and one is not as confined to working through limiting apertures such as the opticocarotid and carotid-oculomotor triangles. Furthermore, because the supraorbital approach is a more midline approach than the transsylvian approach, the ability to visualize midline structures such as the infundibulum and upper basilar artery system is often improved. When compared with extended endoscopic endonasal approaches, the keyhole supraorbital approach offers potentially faster operative times, wider apertures for surgical instrumentation, no sinonasal morbidity, and the potential for more rapid recovery and shorter hospital stays, especially if extensive CSF leak repairs and lumbar drainage can be avoided. The drawbacks of the keyhole supraorbital approach are mainly related to the frontal sinus and individual anatomical considerations, as well as the occasional need for frontal lobe retraction. As discussed by Gazzeri et al., neuronavigation is an excellent strategy for avoiding the frontal sinus. In patients with larger frontal sinuses, the keyhole supraorbital approach can still be utilized, but the surgeon must be prepared to cranialize the sinus using a variety of available techniques if a significant breach is to occur or utilize a more lateral trajectory to avoid the sinus altogether. Additional patient-specific anatomical limitations may include a pre-fixed optic chiasm, and a relative “blind spot” working behind the ipsilateral internal carotid artery. The use of the angled endoscope may provide tremendous benefit in such instances, but as the authors caution, both for the endoscope and microscope, excessive heat from any light source is to be prevented by reducing light source intensity and using frequent irrigation. Another potential limitation for safe tumor resection may include tumors with extensive suprasellar and retrosellar extension, especially in the case of craniopharyngiomas. As these tumors may be adherent to the hypothalamus, third ventricle, optic tracts, and posterior communicating arteries/perforators, working under the optic chiasm to remove these tumors, even with the assistance of an angled endoscope, should proceed with tremendous 1
Editorial caution and an emphasis on preservation of neurological function. In some cases, an extended endonasal approach offers a preferred alternative for such tumors because the surgeon can work more closely along the long axis of the tumor and has better visualization of these critical structures when working from below. Finally, as discussed by Gazzeri et al., a relative contraindication to the keyhole supraorbital approach may be midline olfactory groove meningiomas with inferior extension into the midline depression of the olfactory groove or ethmoid sinuses, where adequate visualization and CSF leak repair may be challenging, especially given the inability to perform a standard pericranial flap to reconstruct defects in this region. Furthermore, true Simpson Grade I resections of olfactory groove meningiomas with less frontal lobe edema may be better achieved via an extended endoscopic endonasal approach or bifrontal craniotomy with pericranial flap reconsruction. All in all, the supraorbital eyebrow approach is a mainstay surgical approach for providing access to the anterior skull base and suprasellar, parasellar, and retrosellar regions. The small craniotomy provides an adequate and relatively luxurious aperture for introduction of the endoscope, thereby allowing the surgeon to capitalize on the benefits of endoscopy (improved visualiza-
2
tion, illumination, mobility, and an ability to look around anatomical corners) with acceptable risk to proximal neurovascular structures. As the optics and instrumentation for minimally invasive and endoscopic neurosurgery continue to become commensurate with the rapid evolution of these approaches, the keyhole supraorbital approach is likely to become even more of a preferred approach for a variety of anterior skull base and sellar region lesions. (http://thejns.org/doi/abs/10.3171/2014.7.FOCUS14464) Disclosure The author reports no conflict of interest. References 1. Gazzeri R, Nishiyama Y, Teo C: Endoscopic supraorbital eyebrow approach for the surgical treatment of extraaxial and intraaxial tumors. Neurosurg Focus 37(4):E20, 2014 2. Reisch R, Perneczky A: Ten-year experience with the supraorbital subfrontal approach through an eyebrow skin incision. Neurosurgery 57:242–255, 2005
Please include this information when citing this paper: DOI: 10.3171/2014.7.FOCUS14464.
Neurosurg Focus / Volume 37 / October 2014
Neurosurg Focus 37 (4):E21, 2014 ©AANS, 2014
Editorial
The endoscopic keyhole supraorbital approach Gabriel Zada, M.D. Department of Neurosurgery, University of Southern California, Los Angeles, California
In the current issue of Neurosurgical Focus, Gazzeri et al. present their experience with the endoscopic supraorbital eyebrow approach for a variety of pathological entities of the anterior skull base and parasellar region.1 The keyhole supraorbital approach has steadily become a workhorse operation for neurosurgeons who routinely treat tumors and aneurysms in these anatomical regions.2 The authors are to be acknowledged for further developing this minimally invasive approach and for routinely integrating the endoscope into their practice, which improves overall visualization and facilitates inspection around anatomical corners such as the tuberculum sellae. The authors report accessing and successfully treating a wide variety of lesions in 97 patients with an acceptable rate of morbidity, and they report very few issues related specifically to the eyebrow approach itself (e.g., frontalis nerve paresis, CSF leaks, or wound infections relating to the frontal sinus). The median hospital stay was 2.7 days, which may be one of the most important benefits offered by the keyhole supraorbital approach. For many neurosurgeons who routinely perform endoscopic and minimally invasive operations, the endoscopic keyhole supraorbital craniotomy is a natural and complementary alternative that capitalizes on much of the same optics, technology, and instrumentation as endoscopic endonasal approaches, while also maintaining many of the benefits of a traditional craniotomy (e.g., standard bipolar cautery). The decision to utilize a keyhole supraorbital approach is often made after careful consideration of alternative surgical options for accessing the anterior skull base and parasellar region, often including direct/extended endoscopic endonasal approaches and more traditional open techniques including the pterional transsylvian and bifrontal craniotomy. Ideally, the surgeon is capable of performing all of these approaches and can appropriately select and tailor any of them for a given patient scenario, as they all play useful and validated roles in the management of various skull Neurosurg Focus / Volume 37 / October 2014
base pathology. The major benefits of the supraorbital keyhole approach are the near-complete eradication of postoperative CSF leaks, minimal requirement for brain retraction, and an approach that allows direct visualization and access to the suprasellar region coursing beneath the optic chiasm in a majority of cases. Compared with the pterional transsylvian approach for suprasellar pathology, there is no need to split the sylvian fissure, and one is not as confined to working through limiting apertures such as the opticocarotid and carotid-oculomotor triangles. Furthermore, because the supraorbital approach is a more midline approach than the transsylvian approach, the ability to visualize midline structures such as the infundibulum and upper basilar artery system is often improved. When compared with extended endoscopic endonasal approaches, the keyhole supraorbital approach offers potentially faster operative times, wider apertures for surgical instrumentation, no sinonasal morbidity, and the potential for more rapid recovery and shorter hospital stays, especially if extensive CSF leak repairs and lumbar drainage can be avoided. The drawbacks of the keyhole supraorbital approach are mainly related to the frontal sinus and individual anatomical considerations, as well as the occasional need for frontal lobe retraction. As discussed by Gazzeri et al., neuronavigation is an excellent strategy for avoiding the frontal sinus. In patients with larger frontal sinuses, the keyhole supraorbital approach can still be utilized, but the surgeon must be prepared to cranialize the sinus using a variety of available techniques if a significant breach is to occur or utilize a more lateral trajectory to avoid the sinus altogether. Additional patient-specific anatomical limitations may include a pre-fixed optic chiasm, and a relative “blind spot” working behind the ipsilateral internal carotid artery. The use of the angled endoscope may provide tremendous benefit in such instances, but as the authors caution, both for the endoscope and microscope, excessive heat from any light source is to be prevented by reducing light source intensity and using frequent irrigation. Another potential limitation for safe tumor resection may include tumors with extensive suprasellar and retrosellar extension, especially in the case of craniopharyngiomas. As these tumors may be adherent to the hypothalamus, third ventricle, optic tracts, and posterior communicating arteries/perforators, working under the optic chiasm to remove these tumors, even with the assistance of an angled endoscope, should proceed with tremendous 1
Editorial caution and an emphasis on preservation of neurological function. In some cases, an extended endonasal approach offers a preferred alternative for such tumors because the surgeon can work more closely along the long axis of the tumor and has better visualization of these critical structures when working from below. Finally, as discussed by Gazzeri et al., a relative contraindication to the keyhole supraorbital approach may be midline olfactory groove meningiomas with inferior extension into the midline depression of the olfactory groove or ethmoid sinuses, where adequate visualization and CSF leak repair may be challenging, especially given the inability to perform a standard pericranial flap to reconstruct defects in this region. Furthermore, true Simpson Grade I resections of olfactory groove meningiomas with less frontal lobe edema may be better achieved via an extended endoscopic endonasal approach or bifrontal craniotomy with pericranial flap reconsruction. All in all, the supraorbital eyebrow approach is a mainstay surgical approach for providing access to the anterior skull base and suprasellar, parasellar, and retrosellar regions. The small craniotomy provides an adequate and relatively luxurious aperture for introduction of the endoscope, thereby allowing the surgeon to capitalize on the benefits of endoscopy (improved visualiza-
2
tion, illumination, mobility, and an ability to look around anatomical corners) with acceptable risk to proximal neurovascular structures. As the optics and instrumentation for minimally invasive and endoscopic neurosurgery continue to become commensurate with the rapid evolution of these approaches, the keyhole supraorbital approach is likely to become even more of a preferred approach for a variety of anterior skull base and sellar region lesions. (http://thejns.org/doi/abs/10.3171/2014.7.FOCUS14464) Disclosure The author reports no conflict of interest. References 1. Gazzeri R, Nishiyama Y, Teo C: Endoscopic supraorbital eyebrow approach for the surgical treatment of extraaxial and intraaxial tumors. Neurosurg Focus 37(4):E20, 2014 2. Reisch R, Perneczky A: Ten-year experience with the supraorbital subfrontal approach through an eyebrow skin incision. Neurosurgery 57:242–255, 2005
Please include this information when citing this paper: DOI: 10.3171/2014.7.FOCUS14464.
Neurosurg Focus / Volume 37 / October 2014
