Otology & Neurotology 36:444Y447 Ó 2014, Otology & Neurotology, Inc.
Piezosurgery for the Repair of Middle Cranial Fossa Meningoencephaloceles *Aanand N. Acharya and *†Gunesh P. Rajan *Department of Otolaryngology, Head and Neck Surgery, Fremantle Hospital & Healthcare Service; and ÞSkull base Division, Otolaryngology, Head and Neck Surgery, School of Surgery, Fremantle Hospital Campus, University of Western Australia, Fremantle, Western Australia, Australia
Objectives: To describe the use of a piezosurgery medical device to perform a craniotomy and produce a split calvarial graft for the repair of middle cranial fossa meningoencephaloceles. Study Design: Retrospective case review. Setting: Tertiary referral hospital. Patients: Ten consecutive patients undergoing middle cranial fossa approach for the repair of meningoencephaloceles. Intervention: Therapeutic. Main Outcome Measures: Intraoperative and postoperative complications, success rate as defined by the ability to fashion a split calvarial graft that achieves complete closure of the tegmen defect. As a secondary outcome measure, evidence of integration of the split calvarial bone graft with the adjacent skull base was assessed.
Results: There were no intraoperative or postoperative complications. An appropriately sized calvarial bone graft was produced, and complete closure of the tegmen defect was achieved in all 10 cases. Computed tomography demonstrated evidence of integration of the bone graft in eight cases between 4 and 9 months after surgery. Conclusion: The piezosurgery medical device provides a safe and effective means by which the middle fossa craniotomy and split calvarial bone graft can be produced to repair defects of the middle fossa tegmen, with integration of the bone graft in the majority of cases. Key Words: CraniotomyVEncephaloceleV MeningoceleVMiddle cranial fossaVPiezosurgery.
Surgical access for the purpose of middle fossa encephalocele repair can be achieved by a transmastoid approach, a middle fossa approach, or a combination of these two approaches. The middle fossa approach, which was first reported in this context in 1982 (1), facilitates identification of the encephalocele and the interposition of material to repair dural and tegmen defects. However, a craniotomy is required for this approach, and this procedure can be associated with significant morbidity consequent to injury to adjacent soft tissue structures. These include dural tears, hemorrhage from a dural sinus, late hematoma formation, and meningitis (2). The complication rate is reported to be 7% (3). Fashioning an appropriately proportioned bone graft from the calvarial bone flap to reconstruct tegmen defects can also be challenging and, in cases of large tegmen defects, it may be necessary to use a significant proportion of the bone flap as a graft to support the tegmen repair. This results in a significant reduction in the size of the calvarial bone flap
and a consequent bony defect in the calvarium when the bone flap is replaced during closure. Although the use of ultrasound as a cutting instrument in soft tissue surgery has been well established for two decades (4,5), its use in cutting bone has become recognized more recently. A piezosurgery medical device uses ultrasonic micromovements of 60 to 200 Km/s at a frequency of 29 kHz that are particularly effective at bone removal. This technique for bone removal is associated with a reduced risk of bone necrosis at the cut edge, and bone healing is improved as compared with healing after cuts with a rotating burr or an oscillating saw. This is as a result of preservation of osteocyte function (6), improved control of the inflammatory healing process, and earlier stimulation of bone remodeling (7). The bone marrow cavity is completely restored, and callus formation is minimized (8) by use of piezosurgery technology. The instrument is therefore particularly suitable for the removal of mineralized tissues (bone); however, in contrast to rotating cutting burrs and oscillating saws, it has a minimal effect on soft tissues (9), with no significant trauma to these on contact. Consequently, the piezoelectric ultrasound osteotomy device is ideal for removal of bone at the interface between bone and soft tissues (10)
Otol Neurotol 36:444Y447, 2015.
Address correspondence and reprint requests to Dr. Aanand N. Acharya, F.R.C.S. (ORL-HNS), ENT Department, Fremantle Hospital, P.O. Box 480, Fremantle, WA, 6959, Australia; E-mail: [email protected] The authors disclose no conflicts of interest.
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Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PIEZOSURGERY FOR MENINGOENCEPHALOCELE REPAIR
445
tabula externa (Fig. 2). The precision of the cuts achieved with the piezosurgery osteotome allows for accurate fashioning of these grafts; if required, the entire tabula interna can be removed as a single piece to repair very large bony defects. The edges of the bone graft are smoothed off and the graft is placed into position, with the concave surface facing the middle ear. The vascularized pericranial middle temporal artery flap raised previously is placed over the inferior edge of the craniotomy and into the cranial cavity to cover the bone graft. Any dural defects are addressed using muscle plugs for small defects and temporalis fascia for larger defects. After this, the temporal lobe is allowed to relax back into position over the bony repair. When the tabula externa of the calvarial bone flap is replaced and secured in place, its inferior edge must be positioned with care to avoid compression of the vascularized pericranial flap.
FIG. 1. The piezosurgery device produces a thin osteotomy cut, thereby allowing the craniotomy to be performed with minimal loss of bone and good hemostasis.
such as at the skull base and may allow some of the challenges encountered with the use of the rotating burr or oscillating saw in performing a craniotomy and fashioning the required bone grafts to be overcome. The aim of this article is to present the outcome of a series of patients who underwent a repair of middle cranial fossa encephalocele in whom a piezosurgery medical device was used to perform the craniotomy and fashion a split calvarial bone graft.
RESULTS Ten patients have undergone repair of tympanomastoid encephaloceles by this technique. There were eight women and two men, aged between 18 and 75 years. The demographics and etiology of these cases are presented in Table 1. All patients underwent the standardized surgical approach described above to repair their tegmen defect and associated meningoencephalocele(s). Successful repair was achieved in all 10 cases, with complete closure of the tegmen defect. There were no documented intraoperative or postoperative complications, and all patients were discharged 3 to 5 days postoperatively. Follow-up highresolution CT imaging of the temporal bones confirmed successful repair of the encephaloceles in all cases.
MATERIALS AND METHODS A retrospective case note review was undertaken of all patients who presented with a middle fossa tegmen defect with associated encephalocele and underwent surgical repair via a middle cranial fossa approach using the Piezosurgery Medical (Mectron) device. Patient demographics, the etiology of the encephalocele, details of the operative procedure, postoperative recovery, and subsequent follow-up findings were considered. Preoperative and postoperative computed tomography (CT) imaging was compared to assess for completeness of repair and for integration of the split calvarial bone graft with the adjacent skull base across time.
Surgical Technique The standard middle fossa craniotomy approach (11) was modified and adapted to suit this application. A pedicled deep temporal fascial layer flap is elevated separately to the temporalis muscle and functions as a vascularized pericranial flap during the reconstruction process at the end of the procedure. The craniotomy is centered on the external auditory canal, rather than two-thirds anterior and one-third posterior, to facilitate complete access to the tegmen tympani and tegmen mastoideum. The bone cut achieved with a piezosurgery device is extremely thin (Fig. 1), thus making insertion of a bone flap elevator difficult; consequently, the superior cut is beveled to facilitate insertion of the elevator at an angle suitable for elevation of the bone flap. An appropriately sized calvarial bone graft is acquired by splitting the tabula interna of the calvarial bone flap from the
FIG. 2. An appropriately sized split calvarial bone graft is fashioned. If required, the entire tabula interna can be removed in a single piece. Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
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A. N. ACHARYA AND G. P. RAJAN
TABLE 1. Patient demographics, etiology of the tegmen defect, evidence of bone graft integration, and interval to integration
Patient 1 2 3 4 5 6 7 8 9 10
Sex
Age at surgery (yr)
Etiology
Graft integration?
Female Male Female Female Female Male Female Female Female Female
40 18 35 69 38 28 45 75 70 23
Idiopathic Idiopathic Idiopathic Idiopathic Idiopathic Posttraumatic Iatrogenic Idiopathic Idiopathic Posttraumatic
Yes Yes Yes Yes Yes Yes Yes N/Aa Yes N/Aa
Time to integration (mo) 9 5 6 5 5 4 6 4
a The 6-month postoperative computed tomography scan used to assess for integration is pending for these patients.
Routine serial imaging for monitoring in the postoperative follow-up period demonstrated evidence of integration of the bone graft with the adjacent bone of the skull base in eight of 10 cases (Table 1; Figs. 3 and 4). In the other two cases, the 6-month postoperative CT scan is pending. DISCUSSION Removal of bone in performing a craniotomy or in dissection of the skull base can be complicated by the collateral thermal and mechanical damage associated with the use of rotating burrs or oscillating saws. Potential complications include an excess degree of removal of bone and injury to adjacent soft tissue structures, including neural structures, blood vessels, and dura. These complications have the potential to alter functional outcomes and increase morbidity. Piezosurgery devices use oscillations that are ultrasonic in frequency and microscopic in amplitude, thereby allowing the precise and accurate removal of mineralized structures (bone) while
FIG. 3. Example of a preoperative CT scan demonstrating a tegmen defect and encephalocele impinging on the head of the malleus.
FIG. 4. Postoperative CT demonstrating a reduction of the encephalocele, complete closure of the tegmen defect, and integration of the bone graft with the adjacent skull base. The concave surface of the bone graft faces the middle ear cleft.
sparing soft tissue. It is our experience, and that of other authors in the literature (12), that the use of this technology reduces the risk of morbidity from the osteotomy procedure. The absence of any requirement to apply significant manual pressure eliminates the risk of injury to the surgeon and scrub staff with the active device, facilitates the accurate control of the instrument, and improves the efficiency with which bone is removed by such devices (13). The pattern of bone removal that is required (osteotomy, osteoplasty, drilling, or finishing) is facilitated by surgical tips of appropriate design that, like drill burrs, are interchangeable on the handpiece. The cavitation effect from the device reduces bleeding at the surgical site yet minimizes bone necrosis, thereby optimizing healing at the cut edges (7,8,13,14). Bone healing appears to be improved with the use of piezosurgery, with reduced callus formation in this process (8). The thin cuts achieved with this device and the precision with which the cuts can be made allow the calvarial bone flap to be separated effectively into its tabula externa and tabula interna components. In cases where a large bone graft is required, the entire tabula interna can be split from the tabula externa in a single piece. Thus, a large calvarial bone graft (tabula interna) can be produced for reconstruction of large middle fossa tegmen defects, without compromising closure at the donor site, which is reconstructed very effectively using the preserved tabula externa. It is the authors’ experience that this can be difficult to achieve using rotating burrs or oscillating saws. The benefits associated with the use of piezosurgery have resulted in its increasing application in our unit. The instrument has been used successfully in a variety of skull base approaches and in other surgeries where there has been a requirement to remove bone adjacent to soft tissue structures that need to be preserved. These include approaches to the internal acoustic meatus, infratemporal fossa approaches, facial translocations, and lateral transphenoidal and mandibulotomy procedures.
Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PIEZOSURGERY FOR MENINGOENCEPHALOCELE REPAIR CONCLUSION In the middle cranial fossa approach to the repair of tympanomastoid meningoencephaloceles, a piezosurgery medical device can provide a safe and efficient technique for performing the craniotomy and fashioning a reconstructive bone graft. Morbidity from adjacent soft tissue injury is minimized, large bone grafts can be made available to repair the tegmen defect(s), and effective preservation of the dimensions of the tabula externa of the calvarial bone flap facilitates a robust, quick, and nearcomplete bony repair. REFERENCES 1. Graham MD. Surgical management of dural and temporal lobe herniation into the radical mastoid cavity. Laryngoscope 1982;92: 329Y31. 2. Kellman RM. Bone grafting for defects of the orbital floor. Arch Otolaryngol Head Neck Surg 1998;124:1402. 3. Legnani FG, Saladino A, Casali C, et al. Craniotomy vs. craniectomy for posterior fossa tumours: a prospective study to evaluate complications after surgery. Acta Neurochirurgica 2013;155:2281Y6. 4. Eichfeld U, Tannapfel A, Steinert M, et al. Evaluation of ultracision in lung metastatic surgery. Ann Thor Surg 2000;70:1181Y4.
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5. Farin G. Ultrasonic dissection in combination with high-frequency surgery. Endosc Surg Allied Technol 1994;2:211Y3. 6. Vercelotti T, Crovace A, Palermo A, et al. The piezoelectric osteotomy in orthopedics: clinical and histological evaluations (pilot study in animals). Mediterranean J Surg Med 2001;9:89Y95. 7. Preti G, Martinasso G, Peirone B, et al. Cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs. J Periodontol 2007;78:716Y22. 8. Stubinger S, Goethe JW. Bone healing after Piezosurgery and its influence on clinical applications. J Oral Maxillofac Surg 2007;65: 39.e7Y8. 9. Vercellotti T. Technological characteristics and clinical indications of piezoelectric bone surgery. Minerva Stomatol 2004; 53:207Y14. 10. Gonzalez-Lagunas J, Mareque J. Calvarial bone harvesting with piezoelectric device. J Craniofac Surg 2007;18:1395Y6. 11. House WF. Surgical exposure of the internal auditory canal and its contents through the middle cranial fossa. Laryngoscope 1961; 71:1363. 12. Kotrikova B, Wirtz R, Krempien R, et al. Piezosurgery Y a new safe technique in cranial osteoplasty? Int J Oral Maxillofac Surg 2006; 35:461Y5. 13. Kramer FJ, Ludwig HC, Materna T, et al. Piezoelectric osteotomies in craniofacial procedures: a series of 15 pediatric patients. Technical note. J Neurosurg 2006;104:68Y71. 14. Reside J, Everett E, Padilla R, et al. In vivo assessment of bone healing following Piezotome Ultrasonic Instrumentation. Clin Implant Dent Relat Res 2013 June 13 (published online ahead of print).
Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
Piezosurgery for the Repair of Middle Cranial Fossa Meningoencephaloceles *Aanand N. Acharya and *†Gunesh P. Rajan *Department of Otolaryngology, Head and Neck Surgery, Fremantle Hospital & Healthcare Service; and ÞSkull base Division, Otolaryngology, Head and Neck Surgery, School of Surgery, Fremantle Hospital Campus, University of Western Australia, Fremantle, Western Australia, Australia
Objectives: To describe the use of a piezosurgery medical device to perform a craniotomy and produce a split calvarial graft for the repair of middle cranial fossa meningoencephaloceles. Study Design: Retrospective case review. Setting: Tertiary referral hospital. Patients: Ten consecutive patients undergoing middle cranial fossa approach for the repair of meningoencephaloceles. Intervention: Therapeutic. Main Outcome Measures: Intraoperative and postoperative complications, success rate as defined by the ability to fashion a split calvarial graft that achieves complete closure of the tegmen defect. As a secondary outcome measure, evidence of integration of the split calvarial bone graft with the adjacent skull base was assessed.
Results: There were no intraoperative or postoperative complications. An appropriately sized calvarial bone graft was produced, and complete closure of the tegmen defect was achieved in all 10 cases. Computed tomography demonstrated evidence of integration of the bone graft in eight cases between 4 and 9 months after surgery. Conclusion: The piezosurgery medical device provides a safe and effective means by which the middle fossa craniotomy and split calvarial bone graft can be produced to repair defects of the middle fossa tegmen, with integration of the bone graft in the majority of cases. Key Words: CraniotomyVEncephaloceleV MeningoceleVMiddle cranial fossaVPiezosurgery.
Surgical access for the purpose of middle fossa encephalocele repair can be achieved by a transmastoid approach, a middle fossa approach, or a combination of these two approaches. The middle fossa approach, which was first reported in this context in 1982 (1), facilitates identification of the encephalocele and the interposition of material to repair dural and tegmen defects. However, a craniotomy is required for this approach, and this procedure can be associated with significant morbidity consequent to injury to adjacent soft tissue structures. These include dural tears, hemorrhage from a dural sinus, late hematoma formation, and meningitis (2). The complication rate is reported to be 7% (3). Fashioning an appropriately proportioned bone graft from the calvarial bone flap to reconstruct tegmen defects can also be challenging and, in cases of large tegmen defects, it may be necessary to use a significant proportion of the bone flap as a graft to support the tegmen repair. This results in a significant reduction in the size of the calvarial bone flap
and a consequent bony defect in the calvarium when the bone flap is replaced during closure. Although the use of ultrasound as a cutting instrument in soft tissue surgery has been well established for two decades (4,5), its use in cutting bone has become recognized more recently. A piezosurgery medical device uses ultrasonic micromovements of 60 to 200 Km/s at a frequency of 29 kHz that are particularly effective at bone removal. This technique for bone removal is associated with a reduced risk of bone necrosis at the cut edge, and bone healing is improved as compared with healing after cuts with a rotating burr or an oscillating saw. This is as a result of preservation of osteocyte function (6), improved control of the inflammatory healing process, and earlier stimulation of bone remodeling (7). The bone marrow cavity is completely restored, and callus formation is minimized (8) by use of piezosurgery technology. The instrument is therefore particularly suitable for the removal of mineralized tissues (bone); however, in contrast to rotating cutting burrs and oscillating saws, it has a minimal effect on soft tissues (9), with no significant trauma to these on contact. Consequently, the piezoelectric ultrasound osteotomy device is ideal for removal of bone at the interface between bone and soft tissues (10)
Otol Neurotol 36:444Y447, 2015.
Address correspondence and reprint requests to Dr. Aanand N. Acharya, F.R.C.S. (ORL-HNS), ENT Department, Fremantle Hospital, P.O. Box 480, Fremantle, WA, 6959, Australia; E-mail: [email protected] The authors disclose no conflicts of interest.
444
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PIEZOSURGERY FOR MENINGOENCEPHALOCELE REPAIR
445
tabula externa (Fig. 2). The precision of the cuts achieved with the piezosurgery osteotome allows for accurate fashioning of these grafts; if required, the entire tabula interna can be removed as a single piece to repair very large bony defects. The edges of the bone graft are smoothed off and the graft is placed into position, with the concave surface facing the middle ear. The vascularized pericranial middle temporal artery flap raised previously is placed over the inferior edge of the craniotomy and into the cranial cavity to cover the bone graft. Any dural defects are addressed using muscle plugs for small defects and temporalis fascia for larger defects. After this, the temporal lobe is allowed to relax back into position over the bony repair. When the tabula externa of the calvarial bone flap is replaced and secured in place, its inferior edge must be positioned with care to avoid compression of the vascularized pericranial flap.
FIG. 1. The piezosurgery device produces a thin osteotomy cut, thereby allowing the craniotomy to be performed with minimal loss of bone and good hemostasis.
such as at the skull base and may allow some of the challenges encountered with the use of the rotating burr or oscillating saw in performing a craniotomy and fashioning the required bone grafts to be overcome. The aim of this article is to present the outcome of a series of patients who underwent a repair of middle cranial fossa encephalocele in whom a piezosurgery medical device was used to perform the craniotomy and fashion a split calvarial bone graft.
RESULTS Ten patients have undergone repair of tympanomastoid encephaloceles by this technique. There were eight women and two men, aged between 18 and 75 years. The demographics and etiology of these cases are presented in Table 1. All patients underwent the standardized surgical approach described above to repair their tegmen defect and associated meningoencephalocele(s). Successful repair was achieved in all 10 cases, with complete closure of the tegmen defect. There were no documented intraoperative or postoperative complications, and all patients were discharged 3 to 5 days postoperatively. Follow-up highresolution CT imaging of the temporal bones confirmed successful repair of the encephaloceles in all cases.
MATERIALS AND METHODS A retrospective case note review was undertaken of all patients who presented with a middle fossa tegmen defect with associated encephalocele and underwent surgical repair via a middle cranial fossa approach using the Piezosurgery Medical (Mectron) device. Patient demographics, the etiology of the encephalocele, details of the operative procedure, postoperative recovery, and subsequent follow-up findings were considered. Preoperative and postoperative computed tomography (CT) imaging was compared to assess for completeness of repair and for integration of the split calvarial bone graft with the adjacent skull base across time.
Surgical Technique The standard middle fossa craniotomy approach (11) was modified and adapted to suit this application. A pedicled deep temporal fascial layer flap is elevated separately to the temporalis muscle and functions as a vascularized pericranial flap during the reconstruction process at the end of the procedure. The craniotomy is centered on the external auditory canal, rather than two-thirds anterior and one-third posterior, to facilitate complete access to the tegmen tympani and tegmen mastoideum. The bone cut achieved with a piezosurgery device is extremely thin (Fig. 1), thus making insertion of a bone flap elevator difficult; consequently, the superior cut is beveled to facilitate insertion of the elevator at an angle suitable for elevation of the bone flap. An appropriately sized calvarial bone graft is acquired by splitting the tabula interna of the calvarial bone flap from the
FIG. 2. An appropriately sized split calvarial bone graft is fashioned. If required, the entire tabula interna can be removed in a single piece. Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
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A. N. ACHARYA AND G. P. RAJAN
TABLE 1. Patient demographics, etiology of the tegmen defect, evidence of bone graft integration, and interval to integration
Patient 1 2 3 4 5 6 7 8 9 10
Sex
Age at surgery (yr)
Etiology
Graft integration?
Female Male Female Female Female Male Female Female Female Female
40 18 35 69 38 28 45 75 70 23
Idiopathic Idiopathic Idiopathic Idiopathic Idiopathic Posttraumatic Iatrogenic Idiopathic Idiopathic Posttraumatic
Yes Yes Yes Yes Yes Yes Yes N/Aa Yes N/Aa
Time to integration (mo) 9 5 6 5 5 4 6 4
a The 6-month postoperative computed tomography scan used to assess for integration is pending for these patients.
Routine serial imaging for monitoring in the postoperative follow-up period demonstrated evidence of integration of the bone graft with the adjacent bone of the skull base in eight of 10 cases (Table 1; Figs. 3 and 4). In the other two cases, the 6-month postoperative CT scan is pending. DISCUSSION Removal of bone in performing a craniotomy or in dissection of the skull base can be complicated by the collateral thermal and mechanical damage associated with the use of rotating burrs or oscillating saws. Potential complications include an excess degree of removal of bone and injury to adjacent soft tissue structures, including neural structures, blood vessels, and dura. These complications have the potential to alter functional outcomes and increase morbidity. Piezosurgery devices use oscillations that are ultrasonic in frequency and microscopic in amplitude, thereby allowing the precise and accurate removal of mineralized structures (bone) while
FIG. 3. Example of a preoperative CT scan demonstrating a tegmen defect and encephalocele impinging on the head of the malleus.
FIG. 4. Postoperative CT demonstrating a reduction of the encephalocele, complete closure of the tegmen defect, and integration of the bone graft with the adjacent skull base. The concave surface of the bone graft faces the middle ear cleft.
sparing soft tissue. It is our experience, and that of other authors in the literature (12), that the use of this technology reduces the risk of morbidity from the osteotomy procedure. The absence of any requirement to apply significant manual pressure eliminates the risk of injury to the surgeon and scrub staff with the active device, facilitates the accurate control of the instrument, and improves the efficiency with which bone is removed by such devices (13). The pattern of bone removal that is required (osteotomy, osteoplasty, drilling, or finishing) is facilitated by surgical tips of appropriate design that, like drill burrs, are interchangeable on the handpiece. The cavitation effect from the device reduces bleeding at the surgical site yet minimizes bone necrosis, thereby optimizing healing at the cut edges (7,8,13,14). Bone healing appears to be improved with the use of piezosurgery, with reduced callus formation in this process (8). The thin cuts achieved with this device and the precision with which the cuts can be made allow the calvarial bone flap to be separated effectively into its tabula externa and tabula interna components. In cases where a large bone graft is required, the entire tabula interna can be split from the tabula externa in a single piece. Thus, a large calvarial bone graft (tabula interna) can be produced for reconstruction of large middle fossa tegmen defects, without compromising closure at the donor site, which is reconstructed very effectively using the preserved tabula externa. It is the authors’ experience that this can be difficult to achieve using rotating burrs or oscillating saws. The benefits associated with the use of piezosurgery have resulted in its increasing application in our unit. The instrument has been used successfully in a variety of skull base approaches and in other surgeries where there has been a requirement to remove bone adjacent to soft tissue structures that need to be preserved. These include approaches to the internal acoustic meatus, infratemporal fossa approaches, facial translocations, and lateral transphenoidal and mandibulotomy procedures.
Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
PIEZOSURGERY FOR MENINGOENCEPHALOCELE REPAIR CONCLUSION In the middle cranial fossa approach to the repair of tympanomastoid meningoencephaloceles, a piezosurgery medical device can provide a safe and efficient technique for performing the craniotomy and fashioning a reconstructive bone graft. Morbidity from adjacent soft tissue injury is minimized, large bone grafts can be made available to repair the tegmen defect(s), and effective preservation of the dimensions of the tabula externa of the calvarial bone flap facilitates a robust, quick, and nearcomplete bony repair. REFERENCES 1. Graham MD. Surgical management of dural and temporal lobe herniation into the radical mastoid cavity. Laryngoscope 1982;92: 329Y31. 2. Kellman RM. Bone grafting for defects of the orbital floor. Arch Otolaryngol Head Neck Surg 1998;124:1402. 3. Legnani FG, Saladino A, Casali C, et al. Craniotomy vs. craniectomy for posterior fossa tumours: a prospective study to evaluate complications after surgery. Acta Neurochirurgica 2013;155:2281Y6. 4. Eichfeld U, Tannapfel A, Steinert M, et al. Evaluation of ultracision in lung metastatic surgery. Ann Thor Surg 2000;70:1181Y4.
447
5. Farin G. Ultrasonic dissection in combination with high-frequency surgery. Endosc Surg Allied Technol 1994;2:211Y3. 6. Vercelotti T, Crovace A, Palermo A, et al. The piezoelectric osteotomy in orthopedics: clinical and histological evaluations (pilot study in animals). Mediterranean J Surg Med 2001;9:89Y95. 7. Preti G, Martinasso G, Peirone B, et al. Cytokines and growth factors involved in the osseointegration of oral titanium implants positioned using piezoelectric bone surgery versus a drill technique: a pilot study in minipigs. J Periodontol 2007;78:716Y22. 8. Stubinger S, Goethe JW. Bone healing after Piezosurgery and its influence on clinical applications. J Oral Maxillofac Surg 2007;65: 39.e7Y8. 9. Vercellotti T. Technological characteristics and clinical indications of piezoelectric bone surgery. Minerva Stomatol 2004; 53:207Y14. 10. Gonzalez-Lagunas J, Mareque J. Calvarial bone harvesting with piezoelectric device. J Craniofac Surg 2007;18:1395Y6. 11. House WF. Surgical exposure of the internal auditory canal and its contents through the middle cranial fossa. Laryngoscope 1961; 71:1363. 12. Kotrikova B, Wirtz R, Krempien R, et al. Piezosurgery Y a new safe technique in cranial osteoplasty? Int J Oral Maxillofac Surg 2006; 35:461Y5. 13. Kramer FJ, Ludwig HC, Materna T, et al. Piezoelectric osteotomies in craniofacial procedures: a series of 15 pediatric patients. Technical note. J Neurosurg 2006;104:68Y71. 14. Reside J, Everett E, Padilla R, et al. In vivo assessment of bone healing following Piezotome Ultrasonic Instrumentation. Clin Implant Dent Relat Res 2013 June 13 (published online ahead of print).
Otology & Neurotology, Vol. 36, No. 3, 2015
Copyright © 2015 Otology & Neurotology, Inc. Unauthorized reproduction of this article is prohibited.
