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Anterior craniofacial resection without facial skin incisions–A review
REVIEW Anterior craniofacial resection without facial skin incisions–A review GADY HAR-EL,
MD,
Brooklyn, New York
A nterior craniofacial resection (ACFR) has become a standard procedure for management of lesions of the anterior skull base. ACFR is probably one of the only few surgical extirpative procedures in head and neck surgery that expanded our ability to actually remove tumors and increase cure rates during the last 40 years. Most of other novel surgical procedures in head and neck surgery were introduced to increase anatomic and functional preservation and to improve reconstruction, but rarely do they increase extirpative abilities. The history of anterior skull base surgery in general, and ACFR in particular, has been beautifully summarized by Donald.1 Dandy2 reported removal of an orbital tumor via anterior craniotomy which included entering the ethmoid complex. This procedure, which we term today the “craniotomy only” approach, was followed by Rae and McLean,3 who utilized a combined transorbital-transcranial approach, and by Smith et al,4 who utilized a combined transfacial-transcranial approach for tumor removal. ACFR as we know it today is based on the original work by Ketcham et al.5 In fact, the “classic” anterior craniofacial resection we perform today uses the same facial skin incisions combined with a bicoronal incision, as well as the same resection steps described by Ketcham in the 1960’s. The “classic” ACFR has been shown to positively impact treatment of paranasal sinus tumors extending to the anterior skull base.6,7 From the Departments of Otolaryngology and Neurosurgery, State University of New York–Downstate Medical Center, Brooklyn, and Continuum Cancer Centers, New York. Reprint requests: Gady Har-El, MD, Department of Otolaryngology, 134 Atlantic Avenue, Brooklyn, NY 11201. Otolaryngol Head Neck Surg 2004;130:780-7. 0194-5998/$30.00 Copyright © 2004 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.01.015 780
With time, modifications of ACFR have been reported. Surgeons have modified the “classic” ACFR procedure in order to improve exposure, reduce complication rate, extend tumor resection abilities (eg, orbitocranial approaches and combined anterior/middle cranial base approaches), preserve function (eg, vision or smell), improve reconstruction, and improve cosmesis. One subset of modifications of an ACFR includes procedures that were introduced to avoid facial skin incisions while preserving extirpative abilities and avoiding higher (or even reducing) complication rates. These procedures are summarized in this review. SURGICAL PROCEDURES The “Craniotomy Only” Approach Certain tumors may have histology, size, and location characteristics which allow complete and safe removal “from above.” Examples include benign or premalignant (inverted papilloma) tumors limited to the superior aspect of the ethmoid complex as well as esthesioneuroblastoma limited to the superior and middle meati (Fig 1). The size of the intracranial component of the tumor does not contraindicate this procedure. Therefore, this procedure is also suitable for frontal or olfactory groove meningiomas with extension into one or both ethmoid sinuses or superior nasal cavity. The procedure includes conventional frontal craniotomy, elevation of one or both frontal lobes after controlled lumbar spinal fluid drainage, and tumor removal. Every attempt should be made to enter the ethmoid complex away from the tumor margin. For superior meatal esthesioneuroblastoma, lateral entry into the ethmoid complex will allow en bloc resection with clear margins. For a tumor involving the ethmoid complex, entry may be performed into the orbit through its roof. Careful study of the intracranial aspects of anterior skull base anatomy is crucial in order to correlate the
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Fig 1. Mucoepidermoid carcinoma of anterior skull base. Limited size and extension make this tumor suitable for the “craniotomy only” approach. (A): Preoperative coronal magnetic resonance (MR). (B): Tumor removal. Preparation for pericranial flap reconstruction. (C): Postoperative coronal MR. (D): Postoperative sagittal MR.
bony anatomy above and below the skull base. Reconstruction of the anterior skull base is usually achieved with a pericranial or pericranial/galeal flap. Rarely, a temporoparietal flap may be required. The main disadvantages of this approach include the need for frontal lobe retraction and olfactory damage, especially in bilateral cases. The Subcranial Approach This approach has received much attention during the last 15 years, mainly because of the exten-
sive work done by Raveh and his colleagues.8 The only incision used for this approach is the bicoronal scalp one. The craniotomy includes the medial aspect of both orbital rims as well as the glabella and part of the nasal bones. The anterior skull base is approached from the anterior and not from above as done in conventional craniotomy. Therefore, there is significantly less need for frontal lobe retraction. This advantage makes the postoperative course less complicated; recovery is quicker, and hospital stay is shorter. The procedure provides us
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Fig 2. The subcranial approach. (A): Bony cuts. (B): Tumor removal. (C): Replacement of bone with resorbable plates and screws. An outer table bone graft to the nasal dorsum was used to achieve a better cosmetic result in this case.
with excellent control of both orbits and both ethmoid complexes. After the craniotomy is completed, resection can be performed intradurally or extradurally, depending on the exact nature and extent of the tumor (Fig 2). ACFR with the Midfacial Degloving (MFD) Approach The Midfacial Degloving (MFD) approach can be combined with either conventional craniotomy or the subcranial approach for a complete anterior craniofacial resection.9-11 The MFD approach provides an excellent exposure of both nasal cavities, ethmoid complexes, maxillary sinuses, ethmoid roof, cribriform plates, sphenoid sinuses, and nasopharynx.9 Therefore, it is especially suitable for bilateral disease (Fig 3). Although the pterygopalatine fossa is easily approached via the MFD, it will require dissection through the maxillary sinus, palate, or nasal cavity. In large bulky tumors in-
volving all sinuses and hard palate, it may necessitate dissection through tumor. Therefore, in large, bulky, malignant tumors, which involve the pterygopalatine fossa or the posterior wall of the maxillary sinus, the author prefers the lateral rhinotomy approach, which provides a direct lateralto-medial access to the pterygopalatine fossa, pterygoid plates, and central skull base. Cocke and Robertson12 described the extended unilateral maxillotomy approach to the skull base, which is carried out through the midfacial degloving approach. The procedure includes osteotomies around the maxilla, through the lateral nasal wall, and through the hard palate, resulting in complete mobilization of the maxilla/hard palate complex, which remains attached to the soft palate. Retraction of the maxillary complex inferiorly, or its rotation to the contralateral side, provides exposure of the central skull base. Again, this can be combined with craniotomy.
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Fig 3. Poorly differentiated neuroendocrine carcinoma of both ethmoids, orbital walls, and anterior skull base. (A): Pretreatment. (B): After 6 cycles of chemotherapy. Despite excellent response, there is persistent tumor in the midline. Also, the surgeon should explore the sites of the original tumor. (C): MFD approach (combined with craniotomy) to bilateral sphenoethmoidectomy, total septectomy, and anterior cranial base resection. (D): CT scan 2 1/2years after surgery. (E): Frontal view after 2 years. (F): Lateral view after 2 years.
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ACFR with LeFort I Osteotomy Although described mainly for approaching the middle and central skull base regions, a LeFort I approach can be used to expose and treat anterior skull base lesions. When combined with craniotomy, the lesion is approached from above as well as through the oral cavity. The angle of the transfacial component of the procedure is similar to the angle achieved with the midfacial degloving approach. However, there is no need to perform medial maxillectomy first in order to approach the orbit, ethmoid complex, and superior nasal cavity. Therefore, after reassembling the midfacial skeleton at the conclusion of the procedure, a large maxillectomy cavity with its long-term morbidity is avoided. ACFR with LeForte I osteotomy requires knowledge and expertise with midfacial plating as well as careful attention to dental occlusion. Endoscopic-Assisted ACFR With this procedure, we use transnasal telescopes to assist with ACFR, which is done transcranially through either the “craniotomy only” or the subcranial approach.13 There is some disagreement in the literature regarding the terms “endoscopic craniofacial resection” and “endoscopicassisted craniofacial resection.”14-16 We limit the term “endoscopic-assisted ACFR” to surgical procedure where telescopes are used for guidance and determination of inferior margins of resection. Actual tumor removal is NOT done endoscopically with this technique. Osteotomes or other instruments passed from the cranial side of resection into the nasal cavity or the ethmoid complex can be guided with the help of endoscopes. The orientation and direction of a posterior septal cut, or a lateral ethmoid entry, or an anterior septal cut, and their relations to the tumor can be determined endoscopically. This will ensure safe margins around the tumor. Limited inferior cuts such as inferior nasal septal cut or medial maxillary wall cut can be done through the nose with the help of endoscopes. Actual en-bloc removal of the tumor specimen is done from above (Fig 4). Endoscopic ACFR without Craniotomy This procedure has been described by Casiano,17,18 who reported good results with its application for management of esthesioneuroblas-
Otolaryngology– Head and Neck Surgery May/June 2004
toma. It begins with endoscopic management of the intranasal component of the tumor. Depending on the extent of the tumor, complete anterior and posterior ethmoidectomy as well as sphenoid sinusotomy are performed. For midline or bilateral tumor, bilateral ethmoidectomy is performed. The intranasal procedure will also include endoscopic medial maxillectomy if the tumor involves the lateral nasal wall. The actual skull base resection is done in an anterior-to-posterior direction. It begins with a wide, bilateral frontal sinusotomy (modified Lothrop procedure), with wide exposure of the posterior frontal sinus wall on both sides. The anterior cranial fossa is entered through the posterior frontal sinus wall. The dura is also entered and the procedure may be carried out extradurally and intradurally on both sides, moving from anterior to posterior. The anterior and posterior ethmoid arteries are cauterized bilaterally. The posterior extent of the resection depends on the extent of the tumor. The skull base may be resected as far as the optic chiasm if necessary. The skull base specimen will include bilateral cribriform plates with the attached dura, the transected crista galli, and the superior part of the nasal septum. Reconstruction of the dural defect is done with either autologous or commercial material. Endoscopic Craniofacial Resection Different variations of this procedure have been described in the literature.13-16 The procedure includes transnasal endoscopic management of the lesion, combined with transcranial approach through either conventional craniotomy or the subfrontal route. With this procedure, unlike the endoscopicassisted craniofacial resection, important components of the resection and tumor removal are performed endoscopically. For non-neoplastic lesions or benign neoplasms, and when the surgeon makes a strategic decision to employ piecemeal removal, tumor removal is actually done endoscopically. For malignant neoplasms, and when the surgeon decides to avoid piecemeal tumor removal, the endoscopic component of the procedure may be used to explore and free the compartments around the tumor. Using the “next compartment” principle, the surgeon will dissect at least one compartment away from the tumor. For example, for an esthesioneuroblastoma occupying both superior meati and the nasal septum,
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Fig 4. Esthesioneuroblastoma. Limited size and inferior extension make this case suitable for endoscopic-assisted ACFR. (A): Preoperative coronal CT. (B): Endoscopic guidance of osteotome placed through the craniotomy. (C): Frontal view 3 years after surgery. (D): Lateral view 3 years after surgery. (E): Well-concealed coronal incision.
the surgeon may use the endoscopic approach to enter the middle meatus on both sides and dissect the ethmoid complex superiorly toward the eth-
moid roof. Depending on the size and extent of the tumor, it may be removed from above or below the skull base.
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Fig 5. Endoscopic ACFR. (A): Blue plastic material is placed under the brain on the anterior skull base. (B): “Blue Sky” seen endoscopically after removal of the lesion.
When performing endoscopic ACFR, we prefer to begin with the intracranial exposure. After craniotomy (conventional or subfrontal), the anterior cranial fossa floor is explored and tumor extent and resectability are defined. If dural involvement that requires resection is identified, it is handled at this time. Then, an appropriately sized sheet of colored plastic material, usually a blue material cut from a Mayo stand cover, is inserted under the dura to sit on top of the bony skull base covering the entire neoplastic process. The brain is now allowed to “sit” on the blue plastic material. The bicoronal scalp flap is temporarily replaced on the cranium, and attention is now directed to the transnasal endoscopic component of the procedure. The blue plastic material provides an excellent visual indication of where the skull base is located. It also prevents accidental dura and brain injury as the surgeon can easily identify it as the superior limit of any surgical manipulation (Fig 5). When the transnasal procedure is completed, and after tumor removal, the blue plastic material is removed. As in any other form of ACFR, a pericranial or galeal/pericranial flap is developed and used to reconstruct the skull base defect. DISCUSSION Patients and caregivers may be tempted to demand and use the procedures described above for management of sinus and skull base tumors because they find that avoiding facial skin inci-
sions is a strongly appealing factor. However, extending the indications for the use of these procedures while compromising our ability to perform complete tumor removal may be hazardous. It has been repeatedly shown that positive surgical margins at the first extirpative procedure have a strong negative impact on outcome and overall survival.7 It is the author’s opinion that a well-placed lateral rhinotomy incision line, with attention to nasal subunits, will result in an excellent cosmetic outcome. Therefore, lateral rhinotomy incision should not be avoided if the use of any other approach may compromise complete tumor removal. The author has found that the use of one of the modifications of ACFR is useful and beneficial in 2 main patient groups: patients with certain malignancies in certain locations and well-defined extent; and patients with benign and non-neoplastic lesions. For malignancies we have always tried to adhere to the “next compartment” rule. It is our goal to perform, when possible, the very first surgical cuts in a space that is at least one compartment away from the tumor. We use this rule because, within the three-dimensional sinus complex and anterior skull base, one cannot use centimeters or millimeters for margin definition as we use in other head and neck locations such as the tongue and skin. Based on preoperative examination and imaging studies, the extent of the tumor and the
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surgeon’s ability to adhere to the “next compartment” rule are assessed. If such an approach is questionable, and if the use of external facial incisions will solve this problem, then a classic ACFR should be performed. Dedicated to the memory of my neurosurgical colleague, Richard M. Swanson, MD. The cooperation of Jon B. Turk, MD, facial plastic and reconstructive surgeon, and Roxanne Todor, MD, neurosurgeon, is greatly appreciated. REFERENCES
1. Donald PJ. History of skull base surgery. In: Donald PJ, editor. Surgery of the skull base. Philadelphia: Lippincott-Raven; 1998. p. 3-13. 2. Dandy WE. Orbital tumor: results following the transcranial operative attack. New York: Oskar Priest; 1941. 3. Rae BS, McLean JM. Combined intracranial and orbital operation for retinoblastoma. Arch Ophthalmol 1943;30: 437-45. 4. Smith RR, Klopp CT, Williams JM. Surgical treatment of cancer of the frontal sinus and adjacent areas. Cancer 1954;7:991-4. 5. Ketcham AS, Wilkins RH, Van Buren JM, et al. A combined intracranial facial approach to the paranasal sinuses. Am J Surg 1963;106:698-703. 6. Arbit A, Shah JP. Combined craniofacial resection for anterior skull base tumors. Neurosurgical Operative Atlas 1991;1:342-52. 7. Patel SG, Singh B, Polluri A, et al. Craniofacial surgery for malignant skull base tumors: report of an international collaboration study. Skull Base 2003;13(suppl 1):7-8.
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8. Raveh J, Laedrach K, Speiser M, et al. The subcranial approach for fronto-orbital and antero-posterior skull base tumors. Arch Otolaryngol Head Neck Surg 1993; 119:382-93. 9. Har-El G, Lucente FE. Midfacial degloving approach to the nose, sinuses and skull base. Am J Rhinol 1996;10: 17-22. 10. Howard DJ, Lund VJ. The role of midfacial degloving in modern rhinologic practice. J Laryngol Otol 1999;113: 885-7. 11. Fliss DM, Zucker G, Amir A, Gatot A. The combined subcranial and midfacial degloving technique for tumor resection: report of three cases. J Oral Maxillofac Surg 2000;58:106-10. 12. Cocke EW, Robertson JH. Extended unilateral maxillotomy approach. In: Donald PJ, editor. Surgery of the skull base. Philadelphia: Lippincott-Raven; 1998. p. 20737. 13. Har-El G, Todor R. Anterior craniofacial resection without facial skin incisions. Skull Base 2003;13(suppl 1):22. 14. Yuen APW, Fung CT, Hung KN. Endoscopic cranionasal resection of anterior skull base tumor. Am J Otolaryngol 1997;18:431-3. 15. Thaler ER, Kotapka M, Lanza DC, et al. Endoscopically assisted anterior cranial skull base resection of sinonasal tumors. Am J Rhinol 1999;13:303-10. 16. Carrau RL, Snyderman CH, Kassam AB, et al. Endoscopic and endoscopic–assisted surgery for juvenile angiofibroma. Laryngoscope 2001;111:483-7. 17. Casiano RR, Numa WA, Falquez AM. Endoscopic resection of esthesioneuroblastoma. Am J Rhinol 2001;15: 271-9. 18. Casiano RR. Anterior skull base resection. In: Casiano RR, editor. Endoscopic sinus surgery dissection manual. New York: Marcel Dekker; 2002. p. 99-101.
MD,
Brooklyn, New York
A nterior craniofacial resection (ACFR) has become a standard procedure for management of lesions of the anterior skull base. ACFR is probably one of the only few surgical extirpative procedures in head and neck surgery that expanded our ability to actually remove tumors and increase cure rates during the last 40 years. Most of other novel surgical procedures in head and neck surgery were introduced to increase anatomic and functional preservation and to improve reconstruction, but rarely do they increase extirpative abilities. The history of anterior skull base surgery in general, and ACFR in particular, has been beautifully summarized by Donald.1 Dandy2 reported removal of an orbital tumor via anterior craniotomy which included entering the ethmoid complex. This procedure, which we term today the “craniotomy only” approach, was followed by Rae and McLean,3 who utilized a combined transorbital-transcranial approach, and by Smith et al,4 who utilized a combined transfacial-transcranial approach for tumor removal. ACFR as we know it today is based on the original work by Ketcham et al.5 In fact, the “classic” anterior craniofacial resection we perform today uses the same facial skin incisions combined with a bicoronal incision, as well as the same resection steps described by Ketcham in the 1960’s. The “classic” ACFR has been shown to positively impact treatment of paranasal sinus tumors extending to the anterior skull base.6,7 From the Departments of Otolaryngology and Neurosurgery, State University of New York–Downstate Medical Center, Brooklyn, and Continuum Cancer Centers, New York. Reprint requests: Gady Har-El, MD, Department of Otolaryngology, 134 Atlantic Avenue, Brooklyn, NY 11201. Otolaryngol Head Neck Surg 2004;130:780-7. 0194-5998/$30.00 Copyright © 2004 by the American Academy of Otolaryngology–Head and Neck Surgery Foundation, Inc. doi:10.1016/j.otohns.2004.01.015 780
With time, modifications of ACFR have been reported. Surgeons have modified the “classic” ACFR procedure in order to improve exposure, reduce complication rate, extend tumor resection abilities (eg, orbitocranial approaches and combined anterior/middle cranial base approaches), preserve function (eg, vision or smell), improve reconstruction, and improve cosmesis. One subset of modifications of an ACFR includes procedures that were introduced to avoid facial skin incisions while preserving extirpative abilities and avoiding higher (or even reducing) complication rates. These procedures are summarized in this review. SURGICAL PROCEDURES The “Craniotomy Only” Approach Certain tumors may have histology, size, and location characteristics which allow complete and safe removal “from above.” Examples include benign or premalignant (inverted papilloma) tumors limited to the superior aspect of the ethmoid complex as well as esthesioneuroblastoma limited to the superior and middle meati (Fig 1). The size of the intracranial component of the tumor does not contraindicate this procedure. Therefore, this procedure is also suitable for frontal or olfactory groove meningiomas with extension into one or both ethmoid sinuses or superior nasal cavity. The procedure includes conventional frontal craniotomy, elevation of one or both frontal lobes after controlled lumbar spinal fluid drainage, and tumor removal. Every attempt should be made to enter the ethmoid complex away from the tumor margin. For superior meatal esthesioneuroblastoma, lateral entry into the ethmoid complex will allow en bloc resection with clear margins. For a tumor involving the ethmoid complex, entry may be performed into the orbit through its roof. Careful study of the intracranial aspects of anterior skull base anatomy is crucial in order to correlate the
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Fig 1. Mucoepidermoid carcinoma of anterior skull base. Limited size and extension make this tumor suitable for the “craniotomy only” approach. (A): Preoperative coronal magnetic resonance (MR). (B): Tumor removal. Preparation for pericranial flap reconstruction. (C): Postoperative coronal MR. (D): Postoperative sagittal MR.
bony anatomy above and below the skull base. Reconstruction of the anterior skull base is usually achieved with a pericranial or pericranial/galeal flap. Rarely, a temporoparietal flap may be required. The main disadvantages of this approach include the need for frontal lobe retraction and olfactory damage, especially in bilateral cases. The Subcranial Approach This approach has received much attention during the last 15 years, mainly because of the exten-
sive work done by Raveh and his colleagues.8 The only incision used for this approach is the bicoronal scalp one. The craniotomy includes the medial aspect of both orbital rims as well as the glabella and part of the nasal bones. The anterior skull base is approached from the anterior and not from above as done in conventional craniotomy. Therefore, there is significantly less need for frontal lobe retraction. This advantage makes the postoperative course less complicated; recovery is quicker, and hospital stay is shorter. The procedure provides us
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Fig 2. The subcranial approach. (A): Bony cuts. (B): Tumor removal. (C): Replacement of bone with resorbable plates and screws. An outer table bone graft to the nasal dorsum was used to achieve a better cosmetic result in this case.
with excellent control of both orbits and both ethmoid complexes. After the craniotomy is completed, resection can be performed intradurally or extradurally, depending on the exact nature and extent of the tumor (Fig 2). ACFR with the Midfacial Degloving (MFD) Approach The Midfacial Degloving (MFD) approach can be combined with either conventional craniotomy or the subcranial approach for a complete anterior craniofacial resection.9-11 The MFD approach provides an excellent exposure of both nasal cavities, ethmoid complexes, maxillary sinuses, ethmoid roof, cribriform plates, sphenoid sinuses, and nasopharynx.9 Therefore, it is especially suitable for bilateral disease (Fig 3). Although the pterygopalatine fossa is easily approached via the MFD, it will require dissection through the maxillary sinus, palate, or nasal cavity. In large bulky tumors in-
volving all sinuses and hard palate, it may necessitate dissection through tumor. Therefore, in large, bulky, malignant tumors, which involve the pterygopalatine fossa or the posterior wall of the maxillary sinus, the author prefers the lateral rhinotomy approach, which provides a direct lateralto-medial access to the pterygopalatine fossa, pterygoid plates, and central skull base. Cocke and Robertson12 described the extended unilateral maxillotomy approach to the skull base, which is carried out through the midfacial degloving approach. The procedure includes osteotomies around the maxilla, through the lateral nasal wall, and through the hard palate, resulting in complete mobilization of the maxilla/hard palate complex, which remains attached to the soft palate. Retraction of the maxillary complex inferiorly, or its rotation to the contralateral side, provides exposure of the central skull base. Again, this can be combined with craniotomy.
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Fig 3. Poorly differentiated neuroendocrine carcinoma of both ethmoids, orbital walls, and anterior skull base. (A): Pretreatment. (B): After 6 cycles of chemotherapy. Despite excellent response, there is persistent tumor in the midline. Also, the surgeon should explore the sites of the original tumor. (C): MFD approach (combined with craniotomy) to bilateral sphenoethmoidectomy, total septectomy, and anterior cranial base resection. (D): CT scan 2 1/2years after surgery. (E): Frontal view after 2 years. (F): Lateral view after 2 years.
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ACFR with LeFort I Osteotomy Although described mainly for approaching the middle and central skull base regions, a LeFort I approach can be used to expose and treat anterior skull base lesions. When combined with craniotomy, the lesion is approached from above as well as through the oral cavity. The angle of the transfacial component of the procedure is similar to the angle achieved with the midfacial degloving approach. However, there is no need to perform medial maxillectomy first in order to approach the orbit, ethmoid complex, and superior nasal cavity. Therefore, after reassembling the midfacial skeleton at the conclusion of the procedure, a large maxillectomy cavity with its long-term morbidity is avoided. ACFR with LeForte I osteotomy requires knowledge and expertise with midfacial plating as well as careful attention to dental occlusion. Endoscopic-Assisted ACFR With this procedure, we use transnasal telescopes to assist with ACFR, which is done transcranially through either the “craniotomy only” or the subcranial approach.13 There is some disagreement in the literature regarding the terms “endoscopic craniofacial resection” and “endoscopicassisted craniofacial resection.”14-16 We limit the term “endoscopic-assisted ACFR” to surgical procedure where telescopes are used for guidance and determination of inferior margins of resection. Actual tumor removal is NOT done endoscopically with this technique. Osteotomes or other instruments passed from the cranial side of resection into the nasal cavity or the ethmoid complex can be guided with the help of endoscopes. The orientation and direction of a posterior septal cut, or a lateral ethmoid entry, or an anterior septal cut, and their relations to the tumor can be determined endoscopically. This will ensure safe margins around the tumor. Limited inferior cuts such as inferior nasal septal cut or medial maxillary wall cut can be done through the nose with the help of endoscopes. Actual en-bloc removal of the tumor specimen is done from above (Fig 4). Endoscopic ACFR without Craniotomy This procedure has been described by Casiano,17,18 who reported good results with its application for management of esthesioneuroblas-
Otolaryngology– Head and Neck Surgery May/June 2004
toma. It begins with endoscopic management of the intranasal component of the tumor. Depending on the extent of the tumor, complete anterior and posterior ethmoidectomy as well as sphenoid sinusotomy are performed. For midline or bilateral tumor, bilateral ethmoidectomy is performed. The intranasal procedure will also include endoscopic medial maxillectomy if the tumor involves the lateral nasal wall. The actual skull base resection is done in an anterior-to-posterior direction. It begins with a wide, bilateral frontal sinusotomy (modified Lothrop procedure), with wide exposure of the posterior frontal sinus wall on both sides. The anterior cranial fossa is entered through the posterior frontal sinus wall. The dura is also entered and the procedure may be carried out extradurally and intradurally on both sides, moving from anterior to posterior. The anterior and posterior ethmoid arteries are cauterized bilaterally. The posterior extent of the resection depends on the extent of the tumor. The skull base may be resected as far as the optic chiasm if necessary. The skull base specimen will include bilateral cribriform plates with the attached dura, the transected crista galli, and the superior part of the nasal septum. Reconstruction of the dural defect is done with either autologous or commercial material. Endoscopic Craniofacial Resection Different variations of this procedure have been described in the literature.13-16 The procedure includes transnasal endoscopic management of the lesion, combined with transcranial approach through either conventional craniotomy or the subfrontal route. With this procedure, unlike the endoscopicassisted craniofacial resection, important components of the resection and tumor removal are performed endoscopically. For non-neoplastic lesions or benign neoplasms, and when the surgeon makes a strategic decision to employ piecemeal removal, tumor removal is actually done endoscopically. For malignant neoplasms, and when the surgeon decides to avoid piecemeal tumor removal, the endoscopic component of the procedure may be used to explore and free the compartments around the tumor. Using the “next compartment” principle, the surgeon will dissect at least one compartment away from the tumor. For example, for an esthesioneuroblastoma occupying both superior meati and the nasal septum,
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Fig 4. Esthesioneuroblastoma. Limited size and inferior extension make this case suitable for endoscopic-assisted ACFR. (A): Preoperative coronal CT. (B): Endoscopic guidance of osteotome placed through the craniotomy. (C): Frontal view 3 years after surgery. (D): Lateral view 3 years after surgery. (E): Well-concealed coronal incision.
the surgeon may use the endoscopic approach to enter the middle meatus on both sides and dissect the ethmoid complex superiorly toward the eth-
moid roof. Depending on the size and extent of the tumor, it may be removed from above or below the skull base.
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Fig 5. Endoscopic ACFR. (A): Blue plastic material is placed under the brain on the anterior skull base. (B): “Blue Sky” seen endoscopically after removal of the lesion.
When performing endoscopic ACFR, we prefer to begin with the intracranial exposure. After craniotomy (conventional or subfrontal), the anterior cranial fossa floor is explored and tumor extent and resectability are defined. If dural involvement that requires resection is identified, it is handled at this time. Then, an appropriately sized sheet of colored plastic material, usually a blue material cut from a Mayo stand cover, is inserted under the dura to sit on top of the bony skull base covering the entire neoplastic process. The brain is now allowed to “sit” on the blue plastic material. The bicoronal scalp flap is temporarily replaced on the cranium, and attention is now directed to the transnasal endoscopic component of the procedure. The blue plastic material provides an excellent visual indication of where the skull base is located. It also prevents accidental dura and brain injury as the surgeon can easily identify it as the superior limit of any surgical manipulation (Fig 5). When the transnasal procedure is completed, and after tumor removal, the blue plastic material is removed. As in any other form of ACFR, a pericranial or galeal/pericranial flap is developed and used to reconstruct the skull base defect. DISCUSSION Patients and caregivers may be tempted to demand and use the procedures described above for management of sinus and skull base tumors because they find that avoiding facial skin inci-
sions is a strongly appealing factor. However, extending the indications for the use of these procedures while compromising our ability to perform complete tumor removal may be hazardous. It has been repeatedly shown that positive surgical margins at the first extirpative procedure have a strong negative impact on outcome and overall survival.7 It is the author’s opinion that a well-placed lateral rhinotomy incision line, with attention to nasal subunits, will result in an excellent cosmetic outcome. Therefore, lateral rhinotomy incision should not be avoided if the use of any other approach may compromise complete tumor removal. The author has found that the use of one of the modifications of ACFR is useful and beneficial in 2 main patient groups: patients with certain malignancies in certain locations and well-defined extent; and patients with benign and non-neoplastic lesions. For malignancies we have always tried to adhere to the “next compartment” rule. It is our goal to perform, when possible, the very first surgical cuts in a space that is at least one compartment away from the tumor. We use this rule because, within the three-dimensional sinus complex and anterior skull base, one cannot use centimeters or millimeters for margin definition as we use in other head and neck locations such as the tongue and skin. Based on preoperative examination and imaging studies, the extent of the tumor and the
Otolaryngology– Head and Neck Surgery Volume 130 Number 6
surgeon’s ability to adhere to the “next compartment” rule are assessed. If such an approach is questionable, and if the use of external facial incisions will solve this problem, then a classic ACFR should be performed. Dedicated to the memory of my neurosurgical colleague, Richard M. Swanson, MD. The cooperation of Jon B. Turk, MD, facial plastic and reconstructive surgeon, and Roxanne Todor, MD, neurosurgeon, is greatly appreciated. REFERENCES
1. Donald PJ. History of skull base surgery. In: Donald PJ, editor. Surgery of the skull base. Philadelphia: Lippincott-Raven; 1998. p. 3-13. 2. Dandy WE. Orbital tumor: results following the transcranial operative attack. New York: Oskar Priest; 1941. 3. Rae BS, McLean JM. Combined intracranial and orbital operation for retinoblastoma. Arch Ophthalmol 1943;30: 437-45. 4. Smith RR, Klopp CT, Williams JM. Surgical treatment of cancer of the frontal sinus and adjacent areas. Cancer 1954;7:991-4. 5. Ketcham AS, Wilkins RH, Van Buren JM, et al. A combined intracranial facial approach to the paranasal sinuses. Am J Surg 1963;106:698-703. 6. Arbit A, Shah JP. Combined craniofacial resection for anterior skull base tumors. Neurosurgical Operative Atlas 1991;1:342-52. 7. Patel SG, Singh B, Polluri A, et al. Craniofacial surgery for malignant skull base tumors: report of an international collaboration study. Skull Base 2003;13(suppl 1):7-8.
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8. Raveh J, Laedrach K, Speiser M, et al. The subcranial approach for fronto-orbital and antero-posterior skull base tumors. Arch Otolaryngol Head Neck Surg 1993; 119:382-93. 9. Har-El G, Lucente FE. Midfacial degloving approach to the nose, sinuses and skull base. Am J Rhinol 1996;10: 17-22. 10. Howard DJ, Lund VJ. The role of midfacial degloving in modern rhinologic practice. J Laryngol Otol 1999;113: 885-7. 11. Fliss DM, Zucker G, Amir A, Gatot A. The combined subcranial and midfacial degloving technique for tumor resection: report of three cases. J Oral Maxillofac Surg 2000;58:106-10. 12. Cocke EW, Robertson JH. Extended unilateral maxillotomy approach. In: Donald PJ, editor. Surgery of the skull base. Philadelphia: Lippincott-Raven; 1998. p. 20737. 13. Har-El G, Todor R. Anterior craniofacial resection without facial skin incisions. Skull Base 2003;13(suppl 1):22. 14. Yuen APW, Fung CT, Hung KN. Endoscopic cranionasal resection of anterior skull base tumor. Am J Otolaryngol 1997;18:431-3. 15. Thaler ER, Kotapka M, Lanza DC, et al. Endoscopically assisted anterior cranial skull base resection of sinonasal tumors. Am J Rhinol 1999;13:303-10. 16. Carrau RL, Snyderman CH, Kassam AB, et al. Endoscopic and endoscopic–assisted surgery for juvenile angiofibroma. Laryngoscope 2001;111:483-7. 17. Casiano RR, Numa WA, Falquez AM. Endoscopic resection of esthesioneuroblastoma. Am J Rhinol 2001;15: 271-9. 18. Casiano RR. Anterior skull base resection. In: Casiano RR, editor. Endoscopic sinus surgery dissection manual. New York: Marcel Dekker; 2002. p. 99-101.