- Email: [email protected]
Integration of image guidance and rapid prototyping technology in craniofacial surgery
Int. J. Oral Maxillofac. Surg. 2013; 42: 970–973 http://dx.doi.org/10.1016/j.ijom.2013.04.019, available online at http://www.sciencedirect.com
Case Report Reconstructive Surgery
Integration of image guidance and rapid prototyping technology in craniofacial surgery
P. Bullock1, D. Dunaway2, L. McGurk3,*, R. Richards4 1 Department of Neurosurgery, Kings College Hospital, London, UK; 2Department of Craniofacial Surgery, Great Ormond Street Children’s Hospital, London, UK; 3Newcastle Medical School, Newcastle, UK; 4Cavendish Imaging, London, UK
P. Bullock, D. Dunaway, L. McGurk, R. Richards: Integration of image guidance and rapid prototyping technology in craniofacial surgery. Int. J. Oral Maxillofac. Surg. 2013; 42: 970–973. # 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. This technical note demonstrates the benefits of preoperative planning, involving the use of rapid prototype models and rehearsal of the surgical procedure, using image-guided navigational surgery. Optimum reconstruction of large defects can be achieved with this technique.
The advent of computer technology has permeated all aspects of medical care and is revolutionizing aspects of modern surgery. The advances made in modern imaging1 have all but eliminated the unexpected event, and consequently the opportunity has arisen to move towards more minimally invasive procedures. Primary intraosseous meningiomas are rare tumours that arise in the skull. They are often benign, and the fronto-parietal and orbital regions are the most common locations. In adults, they usually present with a painless firm swelling. There are often no associated neurological symptoms or signs. The optimum treatment is a wide excision and this is usually curative. However a detailed and complex reconstruction is often needed for intraosseous tumours that involve the orbit, to ensure an excellent functional and cosmetic outcome. The tumours are typically slow-growing and as such there is time to 0901-5027/080970 + 04 $36.00/0
carefully plan the radical excision of the tumour and reconstruction of the cranial defect. The borders of an intraosseous meningioma are often easier to identify from the preoperative magnetic resonance (MR) and high-resolution head computed tomography (CT) imaging than at the time of surgery. This underlines the importance of the preoperative planning to ensure a radical excision of the tumour with careful reconstruction of the wide cranial defect and also an optimum functional and cosmetic outcome. These advances have been facilitated by the introduction of navigational surgical systems,2–4 where detailed CT/MRI/ angiographic images can be superimposed on the computer image of the patient in real time. The ability to take the digital data from CT scans and form an exact replica of the skull and facial bone in plastic using rapid prototyping technology introduces a new
Key words: meningioma; rapid prototyping; surgical navigation; preoperative planning. Accepted for publication 29 April 2013 Available online 31 May 2013
dimension to all disciplines in modern surgery.5 There is the opportunity in complex cases to use the navigation system to rehearse the proposed operation in the laboratory. This allows the operative procedure to be refined and reveals the full extent of the subsequent defect. Consequently the reconstructive phase of the procedure can be planned in advance. Specially prepared templates can be constructed that allow accurate reconstruction of complex shapes rather than trust to experience and fortune on the day.6,7 The present case illustrates the successful amalgam of these two technologies to facilitate the surgery and repair of a significant craniofacial defect. Case
In July 2009 a 56-year-old female was diagnosed with an intraosseous meningioma originating in the region of the left
# 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Image guidance and rapid prototyping in surgery
971
Fig. 1. (a) An image of the skull showing the tumour is made from the CT scan data in nylon. (b) Surgery rehearsed in the laboratory exposes the full extent of the resection.
pterion. Symptoms were minimal; the patient reported occasional sensation of pulsation in the left ear over a period of about 3 years. There was no relevant medical history. The problems that faced the surgical team were first to establish the full extent of the lesion within the bone and the challenge of repairing the resulting defect. The tumour involved the temporal bone together with both the greater and lesser wings of the sphenoid bone. Consequently the function of the left eye was threatened, as the roof, posterior and lateral walls of the orbit had to be sacrificed in the operation. The extent of the tumour was mapped by overlaying CT/MRI and angiography images within the Neurosign tracking system (Brainlab, UK). In addition, the diseased skull was reproduced (Fig. 1) in both plaster (easy to cut) and nylon (autoclavable but not easy to cut) by rapid prototyping technology (Cavendish Imaging, London, UK). The CT images were obtained with the patient wearing a dental plastic bite splint containing four localizing titanium screws. The rapid prototyping models could then be co-localized with the CT images in the Neurosign system, which in turn permitted the operation to be rehearsed in the laboratory. The advantage of this option was that the full extent of the excision could not be determined by virtual images alone and that the tumour margin was more easily determined when the operation was rehearsed. The model
was produced in plaster of Paris that had architectural features that accurately represented the diseased bone. Therefore excision margins could be determined more accurately (Fig. 1b). The advantage was that the reconstruction could be planned in detail. The orbital rim, roof and lateral wall was to be reconstructed in bone and the larger temporal defect restored by a custom-made titanium plate (Fig. 2).
In the present case, any postoperative visual dysfunction was a threat to the patient’s professional career (dentist). A virtual image of the diseased bone in the orbit was produced. A rapid prototyping model of this bone was made. This was then divided into three segments that acted as a template to harvest bone. Using computer software, a donor site was selected on the contralateral cranium where the curvature of the inner table matched that
Fig. 2. An exploded image of the donor bone from the left side of the skull with the inner table removed. The donor site was chosen because the curve of the inner table exactly matched the shape of the orbit so as to minimize volume discrepancies and the risk of diplopia or enophthalmos.
972
Bullock et al.
Fig. 3. The defect in the orbit was replaced with bone fashioned from the inner plate of the contralateral cranium. Screws used to hold the bone segments were positioned so they faced outward and could be removed at a later date if required.
of the orbital walls, and a rapid prototyping model reproduced the harvested bone from the donor site. A second craniotomy was designed with bone harvested from the inner table. An exact replica of the harvested bone was produced again by rapid prototyping technology (Fig. 3). Surgery was uneventful; the tumour was fed from an enlarged middle meningeal
artery which was embolized 48 h prior to surgery. Minor complications included a traction injury to the temporal branch of the facial nerve and a cerebrospinal fluid effusion that persisted (approximately 4 weeks) until the dural defect sealed spontaneously. The patient returned to work at 3 months postsurgery. Orbital appearance and function were normal at the 18-month review (Fig. 4).
Fig. 4. (a) Picture of the patient at 18 months postsurgery. There is no evidence of enophthalmos or diplopia. There is slight wasting of the temporalis muscle and modest weakness of the temporal branch of the facial nerve. (b) Postoperative CT scan taken 2 years after the operation demonstrating near perfect restoration of symmetry.
Discussion
This computer-planned reconstruction of the orbit reduced the element of chance in the reconstruction and the risk of enophthalmos and diplopia. It replaced the traditional and artistic approach to reconstruction with a more reproducible scientific method. The application of modern imaging technology reduces the risk of unexpected events at surgery and also facilitates a more conservative approach to many operative procedures. In the present case, the combination of navigation technology and rapid prototype modelling allowed the operative procedure to be completely rehearsed in the laboratory setting. The advantage was that the full extent of the defect was readily visible and the time was available to plan the subsequent reconstruction in detail so as to minimize any risk of residual facial deformity or orbital dysfunction. Subtle refinement could be made to the surgical plan, such as placement of self-tapping titanium screws in such a position that they could be easily removed at a later date if necessary. Titanium plates were not utilized in the orbital reconstruction in case of late complication (infection or exposure). This degree of detail was a factor of the time available for planning the repair. The extent to which the technology was utilized is illustrated by the use of computer graphics to identify an area on the inner plate of the contralateral temporal bone that matched the curvature required to reform the missing walls of the orbit. Then a rapid prototyping model of the donor site was reconstituted in plastic from the CT scan. Simple plastic templates were designed to optimize the use of the curvature on the inner table of the graft in order to return the orbit to its original shape. These templates exactly
Image guidance and rapid prototyping in surgery mirrored the shape of the roof, rim and lateral wall of the orbit. This took time and experiment. It could not have been achieved reliably if attempted de novo at the time of surgery. Postoperatively there was no evidence of enophthalmos and visual acuity was normal. Orbital and facial contour are symmetrical (Fig. 4b). The application of navigation technology together with rapid prototyping modelling has wide application in facial reconstruction,8 particularly head and neck cancer surgery.9 The ability to carefully model the surgical defect and produce custom-made grafts transforms reconstruction from an art into a science.
2.
3.
4.
Funding
None. Competing interests
None declared.
5.
Ethical approval
Not required. References 1. Tepper OM, Sorice S, Hershman GN, Saadeh P, Levine JP, Hirsch D. Use of virtual
6.
3-dimensional surgery in post-traumatic craniomaxillofacial reconstruction. J Oral Maxillofac Surg 2011;69:733–41. http:// dx.doi.org/10.1016/j.joms.2010.11.028. Schramm A, Suarez-Cunqueiro MM, Barth EL, Essig H, Bormann KH, Kokemueller H, et al. Computer-assisted navigation in craniomaxillofacial tumors. J Craniofac Surg 2008;19:1067–74. http://dx.doi.org/10.1097/ SCS.0b013e3181760fc0. Lu¨bbers HT, Jacobsen C, Matthews F, Gra¨tz KW, Kruse A, Obwegeser JA. Surgical navigation in craniomaxillofacial surgery: expensive toy or useful tool? A classification of different indications. J Oral Maxillofac Surg http://dx.doi.org/10.1016/ 2011;69:300–8. j.joms.2010.07.016. Gregoire C, Adler D, Madey S, Bell RB. Basosquamous carcinoma involving the anterior skull base: a neglected tumor treated using intraoperative navigation as a guide to achieve safe resection margins. J Oral Maxillofac Surg 2011;69:230–6. http://dx.doi.org/ 10.1016/j.joms.2010.06.206. Yu HC, Lee HJ, Jin ZW, Hwang SE, Yang JD, Lim HS, et al. Computer-assisted threedimensional reconstruction of the fetal pancreas including the supplying arteries according to immunohistochemistry of pancreatic polypeptide. Surg Radiol Anat 2012;34:229–33. http://dx.doi.org/10.1007/ s00276-011-0844-4. Hanasono MM, Jacob RF, Bidaut L, Robb GL, Skoracki RJ. Midfacial reconstruction using
973
virtual planning, rapid prototype modeling, and stereotactic navigation. Plast Reconstr Surg 2010;126:2002–6. http://dx.doi.org/ 10.1097/PRS.0b013e3181f447e1. 7. Bell RB, Markiewicz MR. Computer-assisted planning, stereolithographic modeling, and intraoperative navigation for complex orbital reconstruction: a descriptive study in a preliminary cohort. J Oral Maxillofac Surg 2009;67:2559–70. http://dx.doi.org/10.1016/ j.joms.2009.07.098. 8. Levian M, Zandifar H, Osborne RF, Hamilton JS. Three-dimensional CT-guided custom implant for the repair of facial defects. Ear Nose Throat J 2010;89:350–2. 9. Feichtinger M, Pau M, Zemann W, Aigner RM, Ka¨rcher H. Intraoperative control of resection margins in advanced head and neck cancer using a 3D-navigation system based on PET/CT image fusion. J Craniomaxillofac Surg 2010;38:589–94. http://dx.doi.org/10. 1016/j.jcms.2010.02.004.
Address: Lauren McGurk Newcastle Medical School Newcastle NE1 7RU UK Tel: +44 7919417360; Fax: +44 07919417360 E-mails: [email protected], [email protected]
Case Report Reconstructive Surgery
Integration of image guidance and rapid prototyping technology in craniofacial surgery
P. Bullock1, D. Dunaway2, L. McGurk3,*, R. Richards4 1 Department of Neurosurgery, Kings College Hospital, London, UK; 2Department of Craniofacial Surgery, Great Ormond Street Children’s Hospital, London, UK; 3Newcastle Medical School, Newcastle, UK; 4Cavendish Imaging, London, UK
P. Bullock, D. Dunaway, L. McGurk, R. Richards: Integration of image guidance and rapid prototyping technology in craniofacial surgery. Int. J. Oral Maxillofac. Surg. 2013; 42: 970–973. # 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved. Abstract. This technical note demonstrates the benefits of preoperative planning, involving the use of rapid prototype models and rehearsal of the surgical procedure, using image-guided navigational surgery. Optimum reconstruction of large defects can be achieved with this technique.
The advent of computer technology has permeated all aspects of medical care and is revolutionizing aspects of modern surgery. The advances made in modern imaging1 have all but eliminated the unexpected event, and consequently the opportunity has arisen to move towards more minimally invasive procedures. Primary intraosseous meningiomas are rare tumours that arise in the skull. They are often benign, and the fronto-parietal and orbital regions are the most common locations. In adults, they usually present with a painless firm swelling. There are often no associated neurological symptoms or signs. The optimum treatment is a wide excision and this is usually curative. However a detailed and complex reconstruction is often needed for intraosseous tumours that involve the orbit, to ensure an excellent functional and cosmetic outcome. The tumours are typically slow-growing and as such there is time to 0901-5027/080970 + 04 $36.00/0
carefully plan the radical excision of the tumour and reconstruction of the cranial defect. The borders of an intraosseous meningioma are often easier to identify from the preoperative magnetic resonance (MR) and high-resolution head computed tomography (CT) imaging than at the time of surgery. This underlines the importance of the preoperative planning to ensure a radical excision of the tumour with careful reconstruction of the wide cranial defect and also an optimum functional and cosmetic outcome. These advances have been facilitated by the introduction of navigational surgical systems,2–4 where detailed CT/MRI/ angiographic images can be superimposed on the computer image of the patient in real time. The ability to take the digital data from CT scans and form an exact replica of the skull and facial bone in plastic using rapid prototyping technology introduces a new
Key words: meningioma; rapid prototyping; surgical navigation; preoperative planning. Accepted for publication 29 April 2013 Available online 31 May 2013
dimension to all disciplines in modern surgery.5 There is the opportunity in complex cases to use the navigation system to rehearse the proposed operation in the laboratory. This allows the operative procedure to be refined and reveals the full extent of the subsequent defect. Consequently the reconstructive phase of the procedure can be planned in advance. Specially prepared templates can be constructed that allow accurate reconstruction of complex shapes rather than trust to experience and fortune on the day.6,7 The present case illustrates the successful amalgam of these two technologies to facilitate the surgery and repair of a significant craniofacial defect. Case
In July 2009 a 56-year-old female was diagnosed with an intraosseous meningioma originating in the region of the left
# 2013 International Association of Oral and Maxillofacial Surgeons. Published by Elsevier Ltd. All rights reserved.
Image guidance and rapid prototyping in surgery
971
Fig. 1. (a) An image of the skull showing the tumour is made from the CT scan data in nylon. (b) Surgery rehearsed in the laboratory exposes the full extent of the resection.
pterion. Symptoms were minimal; the patient reported occasional sensation of pulsation in the left ear over a period of about 3 years. There was no relevant medical history. The problems that faced the surgical team were first to establish the full extent of the lesion within the bone and the challenge of repairing the resulting defect. The tumour involved the temporal bone together with both the greater and lesser wings of the sphenoid bone. Consequently the function of the left eye was threatened, as the roof, posterior and lateral walls of the orbit had to be sacrificed in the operation. The extent of the tumour was mapped by overlaying CT/MRI and angiography images within the Neurosign tracking system (Brainlab, UK). In addition, the diseased skull was reproduced (Fig. 1) in both plaster (easy to cut) and nylon (autoclavable but not easy to cut) by rapid prototyping technology (Cavendish Imaging, London, UK). The CT images were obtained with the patient wearing a dental plastic bite splint containing four localizing titanium screws. The rapid prototyping models could then be co-localized with the CT images in the Neurosign system, which in turn permitted the operation to be rehearsed in the laboratory. The advantage of this option was that the full extent of the excision could not be determined by virtual images alone and that the tumour margin was more easily determined when the operation was rehearsed. The model
was produced in plaster of Paris that had architectural features that accurately represented the diseased bone. Therefore excision margins could be determined more accurately (Fig. 1b). The advantage was that the reconstruction could be planned in detail. The orbital rim, roof and lateral wall was to be reconstructed in bone and the larger temporal defect restored by a custom-made titanium plate (Fig. 2).
In the present case, any postoperative visual dysfunction was a threat to the patient’s professional career (dentist). A virtual image of the diseased bone in the orbit was produced. A rapid prototyping model of this bone was made. This was then divided into three segments that acted as a template to harvest bone. Using computer software, a donor site was selected on the contralateral cranium where the curvature of the inner table matched that
Fig. 2. An exploded image of the donor bone from the left side of the skull with the inner table removed. The donor site was chosen because the curve of the inner table exactly matched the shape of the orbit so as to minimize volume discrepancies and the risk of diplopia or enophthalmos.
972
Bullock et al.
Fig. 3. The defect in the orbit was replaced with bone fashioned from the inner plate of the contralateral cranium. Screws used to hold the bone segments were positioned so they faced outward and could be removed at a later date if required.
of the orbital walls, and a rapid prototyping model reproduced the harvested bone from the donor site. A second craniotomy was designed with bone harvested from the inner table. An exact replica of the harvested bone was produced again by rapid prototyping technology (Fig. 3). Surgery was uneventful; the tumour was fed from an enlarged middle meningeal
artery which was embolized 48 h prior to surgery. Minor complications included a traction injury to the temporal branch of the facial nerve and a cerebrospinal fluid effusion that persisted (approximately 4 weeks) until the dural defect sealed spontaneously. The patient returned to work at 3 months postsurgery. Orbital appearance and function were normal at the 18-month review (Fig. 4).
Fig. 4. (a) Picture of the patient at 18 months postsurgery. There is no evidence of enophthalmos or diplopia. There is slight wasting of the temporalis muscle and modest weakness of the temporal branch of the facial nerve. (b) Postoperative CT scan taken 2 years after the operation demonstrating near perfect restoration of symmetry.
Discussion
This computer-planned reconstruction of the orbit reduced the element of chance in the reconstruction and the risk of enophthalmos and diplopia. It replaced the traditional and artistic approach to reconstruction with a more reproducible scientific method. The application of modern imaging technology reduces the risk of unexpected events at surgery and also facilitates a more conservative approach to many operative procedures. In the present case, the combination of navigation technology and rapid prototype modelling allowed the operative procedure to be completely rehearsed in the laboratory setting. The advantage was that the full extent of the defect was readily visible and the time was available to plan the subsequent reconstruction in detail so as to minimize any risk of residual facial deformity or orbital dysfunction. Subtle refinement could be made to the surgical plan, such as placement of self-tapping titanium screws in such a position that they could be easily removed at a later date if necessary. Titanium plates were not utilized in the orbital reconstruction in case of late complication (infection or exposure). This degree of detail was a factor of the time available for planning the repair. The extent to which the technology was utilized is illustrated by the use of computer graphics to identify an area on the inner plate of the contralateral temporal bone that matched the curvature required to reform the missing walls of the orbit. Then a rapid prototyping model of the donor site was reconstituted in plastic from the CT scan. Simple plastic templates were designed to optimize the use of the curvature on the inner table of the graft in order to return the orbit to its original shape. These templates exactly
Image guidance and rapid prototyping in surgery mirrored the shape of the roof, rim and lateral wall of the orbit. This took time and experiment. It could not have been achieved reliably if attempted de novo at the time of surgery. Postoperatively there was no evidence of enophthalmos and visual acuity was normal. Orbital and facial contour are symmetrical (Fig. 4b). The application of navigation technology together with rapid prototyping modelling has wide application in facial reconstruction,8 particularly head and neck cancer surgery.9 The ability to carefully model the surgical defect and produce custom-made grafts transforms reconstruction from an art into a science.
2.
3.
4.
Funding
None. Competing interests
None declared.
5.
Ethical approval
Not required. References 1. Tepper OM, Sorice S, Hershman GN, Saadeh P, Levine JP, Hirsch D. Use of virtual
6.
3-dimensional surgery in post-traumatic craniomaxillofacial reconstruction. J Oral Maxillofac Surg 2011;69:733–41. http:// dx.doi.org/10.1016/j.joms.2010.11.028. Schramm A, Suarez-Cunqueiro MM, Barth EL, Essig H, Bormann KH, Kokemueller H, et al. Computer-assisted navigation in craniomaxillofacial tumors. J Craniofac Surg 2008;19:1067–74. http://dx.doi.org/10.1097/ SCS.0b013e3181760fc0. Lu¨bbers HT, Jacobsen C, Matthews F, Gra¨tz KW, Kruse A, Obwegeser JA. Surgical navigation in craniomaxillofacial surgery: expensive toy or useful tool? A classification of different indications. J Oral Maxillofac Surg http://dx.doi.org/10.1016/ 2011;69:300–8. j.joms.2010.07.016. Gregoire C, Adler D, Madey S, Bell RB. Basosquamous carcinoma involving the anterior skull base: a neglected tumor treated using intraoperative navigation as a guide to achieve safe resection margins. J Oral Maxillofac Surg 2011;69:230–6. http://dx.doi.org/ 10.1016/j.joms.2010.06.206. Yu HC, Lee HJ, Jin ZW, Hwang SE, Yang JD, Lim HS, et al. Computer-assisted threedimensional reconstruction of the fetal pancreas including the supplying arteries according to immunohistochemistry of pancreatic polypeptide. Surg Radiol Anat 2012;34:229–33. http://dx.doi.org/10.1007/ s00276-011-0844-4. Hanasono MM, Jacob RF, Bidaut L, Robb GL, Skoracki RJ. Midfacial reconstruction using
973
virtual planning, rapid prototype modeling, and stereotactic navigation. Plast Reconstr Surg 2010;126:2002–6. http://dx.doi.org/ 10.1097/PRS.0b013e3181f447e1. 7. Bell RB, Markiewicz MR. Computer-assisted planning, stereolithographic modeling, and intraoperative navigation for complex orbital reconstruction: a descriptive study in a preliminary cohort. J Oral Maxillofac Surg 2009;67:2559–70. http://dx.doi.org/10.1016/ j.joms.2009.07.098. 8. Levian M, Zandifar H, Osborne RF, Hamilton JS. Three-dimensional CT-guided custom implant for the repair of facial defects. Ear Nose Throat J 2010;89:350–2. 9. Feichtinger M, Pau M, Zemann W, Aigner RM, Ka¨rcher H. Intraoperative control of resection margins in advanced head and neck cancer using a 3D-navigation system based on PET/CT image fusion. J Craniomaxillofac Surg 2010;38:589–94. http://dx.doi.org/10. 1016/j.jcms.2010.02.004.
Address: Lauren McGurk Newcastle Medical School Newcastle NE1 7RU UK Tel: +44 7919417360; Fax: +44 07919417360 E-mails: [email protected], [email protected]