Facial Nerve Paraganglioma Poster Final · PDF fileThe tumor was excised in its entirety. ......
1
Poster Design & Printing by Genigraphics ® - 800.790.4001 Processed Allograft: Novel Use in Facial Nerve Repair after Resection of a Rare Racial Nerve Paraganglioma Stacey Gunn, BS 1 , Maura Cosetti, MD 1 , J. Thomas Roland, Jr., MD 1,2 , Department of Otolaryngology 1 , Department of Neurosurgery 2 , New York University Langone Medical Center, New York, NY, USA DISCUSSION CASE REPORT Figures 1 & 2. SEM images of the endoneural tube structure of Avance Nerve Graft showing the intact basal laminal tubes inherent to the graft. ABSTRACT Objectives: To present a rare case of facial nerve paraganglioma and novel use of a processed allograft for facial nerve reconstruction. Study Design: Case report and review of the literature. Methods: A 34 year old female presented with progressive onset right sided facial palsy for 5 months. CT and MRI demonstrated an irregular mass in the right facial nerve canal from the intra- tympanic segment to the stylomastoid foramen. Results: Following transmastoid resection, the defect was repaired using processed allograft. Pathologic analysis was consistent with a paraganglioma. Facial nerve paraganglioma is a rare entity that has been reported only 10 times in the literature. Conclusions: Traditional methods of facial nerve reconstruction, including autologous and cadaveric grafting, can lead to significant patient morbidity. Autologous nerve grafts are the "gold standard" for superior regenerative capability, but are limited by the length and potential neuroma formation at the donor site. Allogenic grafts from donors or cadavers have shown some efficacy, but can require immunosuppression. The Avance nerve graft is a cadaveric graft, processed and decellularized to maintain an extracellular matrix with laminin and intact endoneural tubes, thus providing support for the growing axon without generating an immune response. Initial studies of the Avance graft in animals and humans have examined repair of peripheral nerves, but this is the first reported case of human facial nerve reconstruction. A 34-year-old female patient presented with progressive right- sided facial nerve palsy x 5 months. She denied hearing loss, tinnitus and vertigo. Her family history is significant for bilateral carotid body tumors in both her father and her first cousin. PE demonstrated a right sided facial paresis consistent with House Brackman (HB) grade III/ VI. Remaining neurologic exam (including cranial nerves, cerebellar, and vestibular exam) and otoscopy were unremarkable. Tuning fork exam and audiogram demonstrated normal hearing bilaterally. CT of the right temporal bone demonstrated soft tissue expansion of the right facial nerve canal from the tympanic segment to the stylomastoid foramen, most prominent in the mastoid segment (6mm x 4mm). MRI revealed an irregular, homogenously enhancing enlargement of the mastoid portion of the right facial nerve. When the paresis worsened to HB IV/VI and the facial twitching became intolerable, a right transmastoid resection of the facial nerve mass and neural reconstruction with processed allograft was performed. A canal wall up tympanomastoidectomy with facial recess was performed and an irregular, friable, vascular mass was encountered along the length of the descending facial nerve. The mastoid portion of CN VII was circumferentially skeletonized to the stylomastoid foramen and the incus removed to allow full access to the tympanic segment. The tumor was excised in its entirety. Frozen sections from the proximal and distal neural ends to be histologically tumor-free. Distally, a neurorrhaphy was performed with 9-0 Prolene between the distal nerve segment and the processed allogen Axogen nerve graft. The tympanic anastomosis was facilitated by laying the allograft in the facial nerve bony channel approximating native normal nerve. A small piece of fascia was placed around each anastomosis and sealed with tissue glue. On histopathologic exam, the tumor cells were immunoreactive for synaptophysin and chromogranin, consistent with a cells of neuroendocrine origin, including paraganglioma. Neurofilament protein and S100 protein identified nerve fibers, and the luxol-fast blue stain highlighted myelinated nerve fibers. The possibility that the tumor cells were metastatic from a primary epithelial neoplasm which had undergone neuroendocrine differentiation was excluded based on the lack of immunostaining for cytokeratin. The finding of Zellballen, which are nests of small cells in a rich, vascular network, further supports this diagnosis. Resection of facial nerve lesions, including the rare facial nerve paragangliomas, requires thorough consideration of reconstructive options. Primary facial nerve repair can be used for lesions up to 18mm and is the best option for achieving return of function. Tensionless reapproximation is the single most important prognostic factor in facial nerve repair. When a primary repair is not possible, autologous nerve grafts are the "gold standard" of repair. Greater auricular or sural nerve match the caliber of the facial nerve and provide 10 cm or 40 cm of nerve, respectively. Drawbacks to autologous grafting include numbness in the distribution of the donor nerve, preparation of a secondary operative site, an additional incision, and harvest-site scarring or neuroma formation. 5 Success rates of cadaveric allografts are similar to autografts, but require immunosuppressed for up to 18 months. Artificial nerve conduits, hollow tubes made of synthetic or collagen material, provide protection to support nerve regeneration, but are only effective over short distances <3cm. 6 Processed allograft retains the endoneural scaffold of nerve tissue, but is non-immunogenic. Cellular components associated with a risk of tissue rejection are removed, while structural and neurotropic components are maintained to support nerve regeneration. An intact extracellular matrix with laminin and collagen encourages axonal growth. Chondroitin sulfate proteoglycans (CSPGs) inhibit nerve regeneration and are washed from the allograft during processing. The Avance processed nerve graft (Axo-Gen, Inc., Alachua, FL) is cadaveric neural tissue that has been processed with a combination of detergent decellularization, chondroitinase CSPG degradation, and gamma-irradiation sterilization. 7 To date, processed allografts have been studied in repair of peripheral, but not cranial nerves. Comparison of the Avance graft to both isograft repair and conduit repair with respect to the number of myelinated fibers, muscle mass, and functional performance with defects of 14mm and 28mm demonstrated that processed nerves were superior to conduits in both histomorphometric measures and functional recovery, but that neither was superior to the isograft. This is likely related to the retention of Schwann cells in the isograft allowing for faster and more complete nerve regeneration. Schwann cells must be removed from the processed allograft as they are a target for immune rejection of the graft. Although the isograft is superior in regenerative ability, the processed allograft is not associated with the same degree of morbidity as the isograft. 6 Short term studies of sensory nerve repair in human hands has demonstrated good-to-excellent recovery in gaps 0.5 cm to 3c m in length, without evidence of infection or graft rejection. 8 Although data related to long term-functional outcomes in humans has not yet been studied, the early results are promising. Paragangliomas are vascular tumors arising from glomus bodies, chemoreceptor cells derived from developing neural crest tissue. These cells are typically found in the adventitia of the jugular bulb (glomus jugulare), along the inferior tympanic canaliculus and over the cochlear prominence (glomus tympanicum), or along Arnold's nerve, the mastoid branch of the vagus nerve (glomus vagale). Large glomus jugulare or glomus tympanicum tumors may secondarily involve the facial nerve canal by direct extension from the jugular foramen or middle ear cavity, but the rare entity of a glomus faciale tumor, a histologically-confirmed primary paraganglioma of the facial nerve, has been reported in the literature only 10 times since the first reported case in 1986. 1 Reported cases included 2 males and 7 females, with ages ranging from 30 to 74 years old. 2,3,4 Surgical management of these tumors inevitably requires sacrifice or resection of the involved portion of the facial nerve. This case highlights a rare case of facial nerve paraganglioma and a novel use of processed allograft for facial nerve reconstruction. 1. Kania RE, Bouccara D, Colombani JM, Molas G, and Sterkers O. Primary Facial Canal Paraganglioma. Am J Otolaryngol 1999; 20:318-322. 2. Connor SEJ, Gleeson MJ, and Odell E. Extracranial glomus faciale tumour. J Laryngol Otol 2008; 122:986-989. 3. Magliulo G, Parnasi E, Savastano V, D'Amico R, and Romeo S. Multiple familial facial glomus: Case report and review of the literature. Ann Otol Rhinol Laryngol 2003; 112:287-292. 4. Wippold FJ, Neely JG, and Haughey BH. Imaging Case of the Month: Primary Paraganglioma of the Facial Nerve Canal. Otol Neurotol 2004; 25:79-80. 5. Humphrey CD and Kriet JD. Nerve repair and cable grafting for facial paralysis. Facial Plast Surg 2008; 24:170-176. 6. Whitlock EL, Tuffaha SH, Luciano JP, et al. Processed allografts and type I collagen conduits for repair of peripheral nerve gaps. Muscle Nerve 2009; 39: 787–799. 7. Deister C, Aljabari S, Schmidt CE, Chang J, and Walpole MT. Processing of a Nerve Graft with Preserved Extracellular Matrix Structure Available at http://axogeninc.us/docs/Processing%20of%20a%20Predegenerated%20and%20Decellularized%20Human%20Graft.pdf. Accessed June 1, 2009. 8. Karabekmez FE, Duymaz A, and Moran SL. Early Clinical Outcomes with the Use of Decellularized Nerve Allograft for Repair of Sensory Defects Within the Hand. Hand (NY) 2009. May 2. REFERENCES J. Thomas Roland, Jr., MD Department of Otolaryngology New York University School of Medicine 550 First Avenue, Suite 8S New York, NY 10016 Tel: 212.263.5565 Fax: 212.263.2019 Email: [email protected] Contact: Figure 3. Laminin stain of an Avance Nerve Graft sample. INTRODUCTION Figure 4. Axial CT images of the right temporal bone demonstrating enlargement of the facial nerve canal from the tympanic segment to the right stylomastoid foramen. At the most expanded point, the descending facial nerve canal measures 6 mm x 4 mm. There is extension into a few mastoid air cells adjacent to the canal. The findings are suspicious for an underlying nerve sheath tumor. Figure 5. Coronal CT images of the right temporal bone demonstrating enlargement of the facial nerve canal at stylomastoid foramen.
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Transcript of Facial Nerve Paraganglioma Poster Final · PDF fileThe tumor was excised in its entirety. ......
Poster Design & Printing by Genigraphics® - 800.790.4001
Processed Allograft: Novel Use in Facial Nerve Repair after Resection of a Rare Racial Nerve Paraganglioma
Stacey Gunn, BS1, Maura Cosetti, MD1, J. Thomas Roland, Jr., MD1,2,Department of Otolaryngology1, Department of Neurosurgery2,
New York University Langone Medical Center, New York, NY, USA
DISCUSSION
CASE REPORT
Figures 1 & 2. SEM images of the endoneural tube structure of Avance Nerve Graft showing the intact basal laminal
tubes inherent to the graft.
ABSTRACT
Objectives:To present a rare case of facial nerve paraganglioma and novel use of a processed allograft for facial nerve reconstruction.
Study Design:Case report and review of the literature.
Methods: A 34 year old female presented with progressive onset right sided facial palsy for 5 months. CT and MRI demonstrated an irregular mass in the right facial nerve canal from the intra-tympanic segment to the stylomastoid foramen.
Results: Following transmastoid resection, the defect was repaired using processed allograft. Pathologic analysis was consistent with a paraganglioma. Facial nerve paraganglioma is a rare entity that has been reported only 10 times in the literature.
Conclusions: Traditional methods of facial nerve reconstruction, including autologous and cadaveric grafting, can lead to significant patient morbidity. Autologous nerve grafts are the "gold standard" for superior regenerative capability, but are limited by the length and potential neuroma formation at the donor site. Allogenic grafts from donors or cadavers have shown some efficacy, but can require immunosuppression. The Avance nerve graft is a cadaveric graft, processed and decellularized to maintain an extracellular matrix with laminin and intact endoneural tubes, thus providing support for the growing axon without generating an immune response. Initial studies of the Avance graft in animals and humans have examined repair of peripheral nerves, but this is the first reported case of human facial nerve reconstruction.
A 34-year-old female patient presented with progressive right-sided facial nerve palsy x 5 months. She denied hearing loss, tinnitus and vertigo. Her family history is significant for bilateral carotid body tumors in both her father and her first cousin.
PE demonstrated a right sided facial paresis consistent with House Brackman (HB) grade III/ VI. Remaining neurologic exam (including cranial nerves, cerebellar, and vestibular exam) and otoscopy were unremarkable. Tuning fork exam and audiogram demonstrated normal hearing bilaterally.
CT of the right temporal bone demonstrated soft tissue expansion of the right facial nerve canal from the tympanic segment to the stylomastoid foramen, most prominent in the mastoid segment (6mm x 4mm). MRI revealed an irregular, homogenously enhancing enlargement of the mastoid portion of the right facial nerve.
When the paresis worsened to HB IV/VI and the facial twitching became intolerable, a right transmastoid resection of the facialnerve mass and neural reconstruction with processed allograft was performed. A canal wall up tympanomastoidectomy with facial recess was performed and an irregular, friable, vascular mass was encountered along the length of the descending facial nerve. The mastoid portion of CN VII was circumferentially skeletonized to the stylomastoid foramen and the incus removed to allow full access to the tympanic segment. The tumor was excised in its entirety. Frozen sections from the proximal and distal neural ends to be histologically tumor-free. Distally, a neurorrhaphy was performed with 9-0 Prolene between the distal nerve segment and the processed allogen Axogen nerve graft. The tympanic anastomosis was facilitated by laying the allograft in the facial nerve bony channel approximating native normal nerve. A small piece of fascia was placed around each anastomosis and sealed with tissue glue.
On histopathologic exam, the tumor cells were immunoreactive for synaptophysin and chromogranin, consistent with a cells of neuroendocrine origin, including paraganglioma. Neurofilament protein and S100 protein identified nerve fibers, and the luxol-fast blue stain highlighted myelinated nerve fibers. The possibility that the tumor cells were metastatic from a primary epithelial neoplasm which had undergone neuroendocrine differentiation was excluded based on the lack of immunostaining for cytokeratin. The finding of Zellballen, which are nests of small cells in a rich, vascular network, further supports this diagnosis.
Resection of facial nerve lesions, including the rare facial nerve paragangliomas, requires thorough consideration of reconstructive options. Primary facial nerve repair can be used for lesions up to 18mm and is the best option for achieving return of function. Tensionless reapproximation is the single most important prognostic factor in facial nerve repair. When a primary repair is not possible, autologous nerve grafts are the "gold standard" of repair. Greater auricular or sural nerve match the caliber of the facial nerve and provide 10 cm or 40 cm of nerve, respectively. Drawbacks to autologous grafting include numbness in the distribution of the donor nerve, preparation of a secondary operative site, an additional incision, and harvest-site scarring or neuroma formation.5 Success rates of cadaveric allografts are similar to autografts, but require immunosuppressed for up to 18 months. Artificial nerve conduits, hollow tubes made of synthetic or collagen material, provide protection to support nerve regeneration, but are only effective over short distances <3cm.6
Processed allograft retains the endoneural scaffold of nerve tissue, but is non-immunogenic. Cellular components associated with a risk of tissue rejection are removed, while structural and neurotropic components are maintained to support nerve regeneration. An intact extracellular matrix withlaminin and collagen encourages axonal growth. Chondroitin sulfate proteoglycans (CSPGs) inhibit nerve regeneration and are washed from the allograft during processing. The Avance processed nerve graft (Axo-Gen, Inc., Alachua, FL) is cadaveric neural tissue that has been processed with a combination of detergent decellularization, chondroitinase CSPG degradation, and gamma-irradiation sterilization.7
To date, processed allografts have been studied in repair of peripheral, but not cranial nerves. Comparison of the Avance graft to both isograft repair and conduit repair with respect tothe number of myelinated fibers, muscle mass, and functional performance with defects of 14mm and 28mm demonstrated that processed nerves were superior to conduits in both histomorphometric measures and functional recovery, but that neither was superior to the isograft. This is likely related to the retention of Schwann cells in the isograft allowing for faster and more complete nerve regeneration. Schwann cells must be removed from the processed allograft as they are a target for immune rejection of the graft. Although the isograft is superior in regenerative ability, the processed allograft is notassociated with the same degree of morbidity as the isograft.6Short term studies of sensory nerve repair in human hands has demonstrated good-to-excellent recovery in gaps 0.5 cm to 3c m in length, without evidence of infection or graft rejection.8 Although data related to long term-functional outcomes in humans has not yet been studied, the early results are promising.
Paragangliomas are vascular tumors arising from glomus bodies, chemoreceptor cells derived from developing neural crest tissue. These cells are typically found in the adventitia of the jugular bulb (glomus jugulare), along the inferior tympanic canaliculus and over the cochlear prominence (glomus tympanicum), or along Arnold's nerve, the mastoid branch of the vagus nerve (glomus vagale). Large glomus jugulare or glomus tympanicum tumors may secondarily involve the facial nerve canal by direct extension from the jugular foramen or middle ear cavity, but the rare entity of a glomus faciale tumor, a histologically-confirmed primary paraganglioma of the facial nerve, has been reported in the literature only 10 times since the first reported case in 1986.1 Reported cases included 2 males and 7 females, with ages ranging from 30 to 74 years old.2,3,4
Surgical management of these tumors inevitably requires sacrifice or resection of the involved portion of the facial nerve. This case highlights a rare case of facial nerve paraganglioma and a novel use of processed allograft for facial nerve reconstruction.
1. Kania RE, Bouccara D, Colombani JM, Molas G, and Sterkers O. Primary Facial Canal Paraganglioma. Am J Otolaryngol 1999; 20:318-322.
2. Connor SEJ, Gleeson MJ, and Odell E. Extracranial glomus faciale tumour. J Laryngol Otol 2008; 122:986-989.3. Magliulo G, Parnasi E, Savastano V, D'Amico R, and Romeo S. Multiple familial facial glomus: Case report and review of the
literature. Ann Otol Rhinol Laryngol 2003; 112:287-292.4. Wippold FJ, Neely JG, and Haughey BH. Imaging Case of the Month: Primary Paraganglioma of the Facial Nerve Canal. Otol
Neurotol 2004; 25:79-80. 5. Humphrey CD and Kriet JD. Nerve repair and cable grafting for facial paralysis. Facial Plast Surg 2008; 24:170-176. 6. Whitlock EL, Tuffaha SH, Luciano JP, et al. Processed allografts and type I collagen conduits for repair of peripheral nerve gaps.
Muscle Nerve 2009; 39: 787–799.7. Deister C, Aljabari S, Schmidt CE, Chang J, and Walpole MT. Processing of a Nerve Graft with Preserved Extracellular Matrix
Structure Available at http://axogeninc.us/docs/Processing%20of%20a%20Predegenerated%20and%20Decellularized%20Human%20Graft.pdf. Accessed June 1, 2009.
8. Karabekmez FE, Duymaz A, and Moran SL. Early Clinical Outcomes with the Use of Decellularized Nerve Allograft for Repair of Sensory Defects Within the Hand. Hand (NY) 2009. May 2.
REFERENCESJ. Thomas Roland, Jr., MDDepartment of OtolaryngologyNew York University School of Medicine550 First Avenue, Suite 8SNew York, NY 10016Tel: 212.263.5565Fax: 212.263.2019Email: [email protected]
Contact:
Figure 3. Laminin stain of an Avance Nerve Graft sample.
INTRODUCTION
Figure 4. Axial CT images of the right temporal bone demonstrating enlargement of the facial nerve canal from the tympanic segment to the right stylomastoid foramen. At the most expanded point, the descending facial nerve canal measures 6 mm x 4 mm. There is extension into a few mastoid air cells adjacent to the canal. The findings are suspicious for an underlying nerve sheath tumor.
Figure 5. Coronal CT images of the right temporal bone demonstrating enlargement of the facial nerve canal at stylomastoid foramen.
