AbstractCoronary artery fistulae (CAF) are rare cardiac anomalies. They frequently arise from the right coronary artery (RCA) with fistulae originating from the left anterior descending artery (LAD) or from multiple arteries being less common. They do not usually cause symptoms and are incidentally diagnosed on routine cardiac imaging. We report a 70years old male patient presenting with chest pain and syncope during physical activity. Diagnostic coronary angiography revealed bilateral multiple CAF originating from both the LAD and RCA. As high blood flow output was recognized in these large vascular anomalies contributing to ‘steal phenomenon’ surgical intervention was planned. This manuscript aimed to present the case and review the current literature for the management and treatment of these coronary anomalies

Bos, Ruud R. M.

Broeckx, Charlotte-Elise

Maal, Thomas J. J.

ter Laan, Mark

Vreeken, Rinaldo D.

University of Groningen Research Database

Single-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction:Technical Note

University of Groningen

   University of GroningenSingle-Step Resection of an Intraosseous Meningioma and Cranial ReconstructionBroeckx, Charlotte-Elise; Maal, Thomas J. J.; Vreeken, Rinaldo D.; Bos, Ruud R. M.; terLaan, MarkPublished in:World neurosurgeryDOI:10.1016/j.wneu.2017.08.177IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2017Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Broeckx, C-E., Maal, T. J. J., Vreeken, R. D., Bos, R. R. M., & ter Laan, M. (2017). Single-Step Resectionof an Intraosseous Meningioma and Cranial Reconstruction: Technical Note. World neurosurgery, 108,225-229. https://doi.org/10.1016/j.wneu.2017.08.177CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 28-04-2023Technical NoteSingle-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction:Technical NoteCharlotte-Elise Broeckx1, Thomas J.J. Maal2,3, Rinaldo D. Vreeken2,3, Ruud R.M. Bos5, Mark ter Laan4-OBJECTIVE: Simultaneous tumor resection and cranialreconstruction can be a challenging task. Surgical navi-gation is an indispensable tool in making this single-stepprocedure possible. In this technical note, we describe anew technique for this procedure to ensure a preciseresection and optimal fit of the implant in a patient with anintraosseous meningioma.-METHODS: We generated a 3-dimensional (3D) model ofthe patient’s skull based on a computed tomography scanand created a digital “resection line” object using 3DStudio Max 2016 software. Based on this object, thepatient-specific implant was generated and printed with a3D printer. Before surgery, the digital object was trans-ferred to the neuronavigation system to enable a navigatedresection of the lesion to ensure maximum precision.During surgery, the craniotomy was performed, and thecustom-made implant was fitted in a single step.-RESULTS: The planned resection was achieved, and theimplant could be fitted without need for further adjustmentsto the resection border.-CONCLUSIONS: We provide a simple technique todigitally define a planned resection site and create acustom-made implant using specialized software and 3Dprinting to enable single-step resection of a skull lesionand cranial reconstruction, thereby reducing surgical timeand costs and ensuring a good cosmetic result.Key words- 3-Dimensional printing- Cranioplasty- Intraosseous meningioma- PMMA- Single-step procedure- Skull lesionAbbreviations and Acronyms3D: 3-DimensionalCT: Computed tomographyPMMA: Polymethyl methacrylateWORLD NEUROSURGERY 108: 225-229, DECEMBER 2017INTRODUCTIONntraosseous meningiomas of the calvarium present as afirm and painless mass on the skull and may be detectedI incidentally, as neurologic signs and symptoms usually areabsent.1 They can, however, become cosmetically disturbing.Wide surgical excision is potentially curative2 but also leavesthe patient with a skull defect for which a reconstruction isrequired. The rapid evolution of imaging techniques,simulation software, computer-aided reconstruction tech-niques, and surgical navigation have made it possible toperform a resection of the tumor and cranioplasty in a singleprocedure. However, precise definition of the resection site toensure an optimal fit of the implant remains a challenge. Wedescribe a new technique using specialized software to facili-tate this process.CASE REPORTHistoryA 68-year-old woman with a history of diabetes, alcoholichepatitis, and Barrett esophagitis was admitted to the neuro-logic department with diplopia. Analysis showed a vitamin B1deficiency, and complaints resolved with substitution. Imagingalso had shown a lesion of the left frontotemporal skull(Figure 1). Further analysis ruled out a primary tumor elsewhereas well as metastases. A biopsy was scheduled in our centerbecause a malignant lesion was suspected. Biopsy showed aWorld Health Organization grade I intraosseous meningioma,and a watchful waiting strategy was chosen because thepatient was without symptoms. Two years later, progressionof the tumor was shown on magnetic resonance scan(Figure 1), and she opted for surgical resection.From the 1Department of Neurosurgery, University Hospital Leuven, Leuven, Belgium;2Radboudumc 3D Lab, 3Department of Oral and Maxillofacial Surgery, and 4Department ofNeurosurgery, Radboud University Medical Center, Nijmegen, The Netherlands; and5Department of Oral and Maxillofacial Surgery, University of Groningen and UniversityMedical Center Groningen, Groningen, The NetherlandsTo whom correspondence should be addressed: Charlotte-Elise Broeckx, M.D.[E-mail: charlotte-elise.broeckx@uzleuven.be]Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.www.WORLDNEUROSURGERY.org 225Figure 1. Magnetic resonance scan at diagnosis (top) and 2 years later at time of progression (bottom).TECHNICAL NOTEPreoperative PlanningA resection and reconstruction in one session was planned.First, a computed tomography (CT) scan (0.5-mm slices) wastaken (Figure 2). Digital Imaging and Communications inMedicine images were exported to Maxilim, version 2.2.2.1(Medicim NV, Mechelen, Belgium) software, and a3-dimensional (3D) model was reconstructed. In 3D StudioMax 2016 (Autodesk Inc., San Rafael, California, USA), thesurgeon drew a digital resection line on the 3D model, whichwas used to generate a “resection line” object. All 3D datawithin the resection line were excluded from the model; themodel was then copied and mirrored. The mirrored and originalmodels were fused (excluding resection), and the 3D data fromthe projection in the previously defined resection area onthe right side of the skull were used to generate a 3D model ofthe implant.Both the model (with the lesion resected) and the implant designwere 3D printed with a FormLabs Form 2 3D Printer (FormlabsInc., Somerville, Massachusetts, USA). The implant was then226 www.SCIENCEDIRECT.com WORLD NEUmade from polymethyl methacrylate (PMMA) by copying the3D-printed implant design in wax. The wax model wasembedded in plaster and burned out after which the space insidethe plaster was filled with hot cured PMMA. The PMMA implantwas polished, cleaned by brushing with soap, and plasmasterilized.The day before surgery, a new magnetic resonance scan wasperformed, which was loaded into iPlan Brainlab software(Brainlab AG, Munich, Germany) and fused with the thin-slice CT.The 3D images of the implant and resection line were importedinto the software as well (Figure 3).Surgical ProcedureDuring surgery, a reference star was fitted on a sterile markerand registered with the Brainlab system. Via the use of thisnavigated sterile marker, the preoperatively defined resectionborder could be drawn onto the patient’s skull during the sur-gery (Figure 4A). The craniotomy was performed following thisROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177Figure 2. Preoperative, thin-slice computed tomography scan with 3-dimensional reconstruction.TECHNICAL NOTEline. Next, the dura around the tumor was resected, and areconstruction was made with periost. Then, the implantcould be put in place and fixed with titanium screws(Figure 4D). The fit of the implant was as planned, so therewas no need to make further adjustments for improvement.Figure 3. Implant model as imported in Brainlab software.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017DISCUSSIONIntraosseous meningiomas are rare lesions that originate in theskull and constitute fewer than 2% of meningiomas overall.Although most are benign, intraosseous meningiomas are morelikely to be malignant than their intradural counterparts. Thetreatment of choice is wide surgical resection, which is poten-tially curative.3 Ideally, cranial reconstruction should occur as partof the same procedure.4Different techniques have been described to perform a single-step procedure: using a preoperatively produced template,5intraoperatively molding an artificial bone flap without atemplate,6,7 or producing a stereolithographic model to helpguide resection and/or design the custom-made implant. Such amodel can be used to create a template to guide resection,8 or itcan be used to manually create the desired resection to producea custom-made implant based on the defect in the model,9sometimes even requiring the model itself to be scanned andthe images to be fused with the original CT images to createthe planned resection line that can be used by theneuronavigation system.10,11 In some cases, adjustments tothe preoperatively produced implants still need to be made.8,9Digitalization of the process of manufacturing a custom-madeimplant has made it possible to produce accurately fitting im-plants with a minimum of intermediate steps, thus avoidingapproximate reconstructions using conventional techniques or 2-step procedures.12 Surgical navigation is an indispensable tool toensure an optimal fit of the implant.We have described a method to perform a single-step tumorresection and cranioplasty in which the preoperatively plannedresection was performed virtually. With the use of specializedsoftware, a digital “resection line” object was created, which waswww.WORLDNEUROSURGERY.org 227Figure 4. (A) Navigation-guided demarcation of theresection margin. (B) The custom-made implant beforeplacement. (C) Situation after navigation-guidedremoval of the bone flap. (D) Perfect fit of the custom-made implant on the site of resection of the bone flap.TECHNICAL NOTEloaded into the navigation system to guide resection duringsurgery. Preoperatively, a custom-made implant was made with a3D-printer, based on the properties of the “resection line” object.Our method has several advantages over other reportedmethods. First, there is no further need to draw a resection lineon a stereolithographic model nor to scan the model since allsteps can be done virtually. This reduces the number ofproduction steps and thus time and costs. Second, navigation-guided resection allows for a fast and precise recreation of thevirtually generated resection line. We did this by using a navi-gated sterile pen; another option would be to connect the228 www.SCIENCEDIRECT.com WORLD NEUoperation microscope to the navigation system and project theimplant or resection line into the microscope. This reducesoperation time, because no adjustments need to be made to theresection margin or the implant itself. Third, the implant wasmanufactured preoperatively, so there was no need to manuallymold an artificial bone flap during surgery.Because the patient-specific model was printed in our 3Dlaboratory, we did not need to collaborate with a commercialmanufacturer. This also greatly reduced the cost of producing theimplant. Momentarily, our workflow is still based on 3D printing astereolithographic model and secondarily creating a PMMAROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177TECHNICAL NOTEimplant, but the methods as presented in this paper wouldperfectly allow immediate printing of implants. We achieved avery satisfying cosmetic result using our method because the fitof the implant was optimal without the need to make furtheradjustments to the implant or the resection margin.The use of 3D printing has become widely available in neuro-surgery,13 specifically in the production of custom-made im-plants.14 However, most case reports and case series presentedin literature describe the use of custom-made implants forreconstructing pre-existing cranial defects, and the use of thistechnique for single-step cranial reconstruction procedures is stillrelatively scarce. Furthermore, there is currently no standard 3Dprinting process for the use in neurosurgical procedures.15 Ourproposed method aims at facilitating this process.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017CONCLUSIONSSingle-step resection and cranioplasty are becoming the stan-dard of care in patients with skull lesions. The use of special-ized software and a navigation system highly facilitate thisprocess. By planning a virtual resection preoperatively andgenerating the resection line as an object that can be loadedinto the navigation system, a precisely navigated resection canbe obtained. Also, based on this object, a custom-made implantis produced before surgery so that the implant fits accuratelyand can be inserted in a single-step procedure. This processensures an optimal fit for the implant while reducingmanufacturing costs and operating time and providing perfectcosmetic results.REFERENCES1. Chen TC. Primary intraosseous meningioma.Neurosurg Clin N Am. 2016;27:189-193.2. Inagaki K, Otsuka F, Matsui T, Ogura T,Makino H. Effect of etidronate on intraosseousmeningioma. Endocr J. 2004;51:389-390.3. Elder JB, Atkinson R, Zee CS, Chen TC. Primaryintraosseous meningioma. Neurosurg Focus. 2007;23:E13.4. Tokgoz N, Oner YA, Kaymaz M, Ucar M,Yilmaz G, Tali TE. Primary intraosseousmeningioma: CT and MRI appearance. AJNR Am JNeuroradiol. 2005;26:2053-2056.5. D’Urso PS, Redmond MJ. A method for theresection of cranial tumours and skull recon-struction. Br J Neurosurg. 2000;14:555-559.6. Bloch O, McDermott MW. In situ cranioplasty forhyperostosing meningiomas of the cranial vault.Can J Neurol Sci. 2011;38:59-64.7. Velnar T, Pregelj R, Limbaeck-Stokin C. Brainmeningioma invading and destructing the skullbone: replacement of the missing bone in vivo.Radiol Oncol. 2011;45:304-309.8. Castle M, Rivero M, Marquez J. Primary Ewing’ssarcoma of the skull: radical resection and im-mediate cranioplasty after chemotherapy. A tech-nical note. Childs Nerv Syst. 2013;29:303-306.9. Saringer W, Nöbauer-Huhmann I, Knosp E.Cranioplasty with individual carbon fibre rein-forced polymere (CFRP) medical grade implantsbased on CAD/CAM technique. Acta Neurochir.2002;144:1193-1203.10. Della Puppa A, Mottaran R, Scienza R. Image-guided cranial osteoma resection and bioceramicporous hydroxyapatite custom-made reconstruc-tion in a one-step surgical procedure. Technicalnotes and illustrative case. Acta Neurochir. 2010;152:155-159.11. Westendorff C, Kaminsky J, Ernemann U, Reinert S,Hoffmann J. Image-guided sphenoid wing menin-gioma resection and simultaneous computer-assisted cranio-orbital reconstruction: technicalcase report. Neurosurgery. 2007;60(2 suppl 1):173-174.12. Jalbert F, Boetto S, Nadon F, Lauwers F,Schmidt E, Lopez R. One-step primary recon-struction for complex craniofacial resection withPEEK custom-made implants. J CraniomaxillofacSurg. 2014;42:141-148.ww13. Tomasello F, Conti A, La Torre D. 3D printing inneurosurgery. World Neurosurg. 2016;91:633-634.14. Bonda DJ, Manjila S, Selman WR, Dean D. Therecent revolution in the design and manufactureof cranial implants: modern advancements andfuture directions. Neurosurgery. 2015;77:814-824.15. Pucci JU, Christophe BR, Sisti JA, Connolly ES Jr.Three-dimensional printing: technologies, appli-cations, and limitations in neurosurgery. BiotechnolAdv. 2017;35:521-529.Conflict of interest statement: The authors declare thatthe article content was composed in the absence of anycommercial or financial relationships that could beconstrued as a potential conflict of interest.Received 27 May 2017; accepted 28 August 2017Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. Allrights reserved.w.WORLDNEUROSURGERY.org 229

English

Maal, T.J.J.

Vreeken, R.D.

Bos, Ruud R.M.

Laan, M. ter

NARCIS 

Single-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction: Technical Note

OBJECTIVE: Simultaneous tumor resection and cranial reconstruction can be a challenging task. Surgical navigation is an indispensable tool in making this single-step procedure possible. In this technical note, we describe a new technique for this procedure to ensure a precise resection and optimal fit of the implant in a patient with an intraosseous meningioma.METHODS: We generated a 3-dimensional (3D) model of the patient's skull based on a computed tomography scan and created a digital "resection line" object using 3D Studio Max 2016 software. Based on this object, the patient-specific implant was generated and printed with a 3D printer. Before surgery, the digital object was transferred to the neuronavigation system to enable a navigated resection of the lesion to ensure maximum precision. During surgery, the craniotomy was performed, and the custom-made implant was fitted in a single step.RESULTS: The planned resection was achieved, and the implant could be fitted without need for further adjustments to the resection border.CONCLUSIONS: We provide a simple technique to digitally define a planned resection site and create a custom-made implant using specialized software and 3D printing to enable single-step resection of a skull lesion and cranial reconstruction, thereby reducing surgical time and costs and ensuring a good cosmetic result.</p

Dissertations of the University of Groningen

   University of GroningenSingle-Step Resection of an Intraosseous Meningioma and Cranial ReconstructionBroeckx, Charlotte-Elise; Maal, Thomas J. J.; Vreeken, Rinaldo D.; Bos, Ruud R. M.; terLaan, MarkPublished in:World neurosurgeryDOI:10.1016/j.wneu.2017.08.177IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2017Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Broeckx, C-E., Maal, T. J. J., Vreeken, R. D., Bos, R. R. M., & ter Laan, M. (2017). Single-Step Resectionof an Intraosseous Meningioma and Cranial Reconstruction: Technical Note. World neurosurgery, 108,225-229. https://doi.org/10.1016/j.wneu.2017.08.177CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 02-11-2023Technical NoteSingle-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction:Technical NoteCharlotte-Elise Broeckx1, Thomas J.J. Maal2,3, Rinaldo D. Vreeken2,3, Ruud R.M. Bos5, Mark ter Laan4-OBJECTIVE: Simultaneous tumor resection and cranialreconstruction can be a challenging task. Surgical navi-gation is an indispensable tool in making this single-stepprocedure possible. In this technical note, we describe anew technique for this procedure to ensure a preciseresection and optimal fit of the implant in a patient with anintraosseous meningioma.-METHODS: We generated a 3-dimensional (3D) model ofthe patient’s skull based on a computed tomography scanand created a digital “resection line” object using 3DStudio Max 2016 software. Based on this object, thepatient-specific implant was generated and printed with a3D printer. Before surgery, the digital object was trans-ferred to the neuronavigation system to enable a navigatedresection of the lesion to ensure maximum precision.During surgery, the craniotomy was performed, and thecustom-made implant was fitted in a single step.-RESULTS: The planned resection was achieved, and theimplant could be fitted without need for further adjustmentsto the resection border.-CONCLUSIONS: We provide a simple technique todigitally define a planned resection site and create acustom-made implant using specialized software and 3Dprinting to enable single-step resection of a skull lesionand cranial reconstruction, thereby reducing surgical timeand costs and ensuring a good cosmetic result.Key words- 3-Dimensional printing- Cranioplasty- Intraosseous meningioma- PMMA- Single-step procedure- Skull lesionAbbreviations and Acronyms3D: 3-DimensionalCT: Computed tomographyPMMA: Polymethyl methacrylateWORLD NEUROSURGERY 108: 225-229, DECEMBER 2017INTRODUCTIONntraosseous meningiomas of the calvarium present as afirm and painless mass on the skull and may be detectedI incidentally, as neurologic signs and symptoms usually areabsent.1 They can, however, become cosmetically disturbing.Wide surgical excision is potentially curative2 but also leavesthe patient with a skull defect for which a reconstruction isrequired. The rapid evolution of imaging techniques,simulation software, computer-aided reconstruction tech-niques, and surgical navigation have made it possible toperform a resection of the tumor and cranioplasty in a singleprocedure. However, precise definition of the resection site toensure an optimal fit of the implant remains a challenge. Wedescribe a new technique using specialized software to facili-tate this process.CASE REPORTHistoryA 68-year-old woman with a history of diabetes, alcoholichepatitis, and Barrett esophagitis was admitted to the neuro-logic department with diplopia. Analysis showed a vitamin B1deficiency, and complaints resolved with substitution. Imagingalso had shown a lesion of the left frontotemporal skull(Figure 1). Further analysis ruled out a primary tumor elsewhereas well as metastases. A biopsy was scheduled in our centerbecause a malignant lesion was suspected. Biopsy showed aWorld Health Organization grade I intraosseous meningioma,and a watchful waiting strategy was chosen because thepatient was without symptoms. Two years later, progressionof the tumor was shown on magnetic resonance scan(Figure 1), and she opted for surgical resection.From the 1Department of Neurosurgery, University Hospital Leuven, Leuven, Belgium;2Radboudumc 3D Lab, 3Department of Oral and Maxillofacial Surgery, and 4Department ofNeurosurgery, Radboud University Medical Center, Nijmegen, The Netherlands; and5Department of Oral and Maxillofacial Surgery, University of Groningen and UniversityMedical Center Groningen, Groningen, The NetherlandsTo whom correspondence should be addressed: Charlotte-Elise Broeckx, M.D.[E-mail: charlotte-elise.broeckx@uzleuven.be]Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.www.WORLDNEUROSURGERY.org 225Figure 1. Magnetic resonance scan at diagnosis (top) and 2 years later at time of progression (bottom).TECHNICAL NOTEPreoperative PlanningA resection and reconstruction in one session was planned.First, a computed tomography (CT) scan (0.5-mm slices) wastaken (Figure 2). Digital Imaging and Communications inMedicine images were exported to Maxilim, version 2.2.2.1(Medicim NV, Mechelen, Belgium) software, and a3-dimensional (3D) model was reconstructed. In 3D StudioMax 2016 (Autodesk Inc., San Rafael, California, USA), thesurgeon drew a digital resection line on the 3D model, whichwas used to generate a “resection line” object. All 3D datawithin the resection line were excluded from the model; themodel was then copied and mirrored. The mirrored and originalmodels were fused (excluding resection), and the 3D data fromthe projection in the previously defined resection area onthe right side of the skull were used to generate a 3D model ofthe implant.Both the model (with the lesion resected) and the implant designwere 3D printed with a FormLabs Form 2 3D Printer (FormlabsInc., Somerville, Massachusetts, USA). The implant was then226 www.SCIENCEDIRECT.com WORLD NEUmade from polymethyl methacrylate (PMMA) by copying the3D-printed implant design in wax. The wax model wasembedded in plaster and burned out after which the space insidethe plaster was filled with hot cured PMMA. The PMMA implantwas polished, cleaned by brushing with soap, and plasmasterilized.The day before surgery, a new magnetic resonance scan wasperformed, which was loaded into iPlan Brainlab software(Brainlab AG, Munich, Germany) and fused with the thin-slice CT.The 3D images of the implant and resection line were importedinto the software as well (Figure 3).Surgical ProcedureDuring surgery, a reference star was fitted on a sterile markerand registered with the Brainlab system. Via the use of thisnavigated sterile marker, the preoperatively defined resectionborder could be drawn onto the patient’s skull during the sur-gery (Figure 4A). The craniotomy was performed following thisROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177Figure 2. Preoperative, thin-slice computed tomography scan with 3-dimensional reconstruction.TECHNICAL NOTEline. Next, the dura around the tumor was resected, and areconstruction was made with periost. Then, the implantcould be put in place and fixed with titanium screws(Figure 4D). The fit of the implant was as planned, so therewas no need to make further adjustments for improvement.Figure 3. Implant model as imported in Brainlab software.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017DISCUSSIONIntraosseous meningiomas are rare lesions that originate in theskull and constitute fewer than 2% of meningiomas overall.Although most are benign, intraosseous meningiomas are morelikely to be malignant than their intradural counterparts. Thetreatment of choice is wide surgical resection, which is poten-tially curative.3 Ideally, cranial reconstruction should occur as partof the same procedure.4Different techniques have been described to perform a single-step procedure: using a preoperatively produced template,5intraoperatively molding an artificial bone flap without atemplate,6,7 or producing a stereolithographic model to helpguide resection and/or design the custom-made implant. Such amodel can be used to create a template to guide resection,8 or itcan be used to manually create the desired resection to producea custom-made implant based on the defect in the model,9sometimes even requiring the model itself to be scanned andthe images to be fused with the original CT images to createthe planned resection line that can be used by theneuronavigation system.10,11 In some cases, adjustments tothe preoperatively produced implants still need to be made.8,9Digitalization of the process of manufacturing a custom-madeimplant has made it possible to produce accurately fitting im-plants with a minimum of intermediate steps, thus avoidingapproximate reconstructions using conventional techniques or 2-step procedures.12 Surgical navigation is an indispensable tool toensure an optimal fit of the implant.We have described a method to perform a single-step tumorresection and cranioplasty in which the preoperatively plannedresection was performed virtually. With the use of specializedsoftware, a digital “resection line” object was created, which waswww.WORLDNEUROSURGERY.org 227Figure 4. (A) Navigation-guided demarcation of theresection margin. (B) The custom-made implant beforeplacement. (C) Situation after navigation-guidedremoval of the bone flap. (D) Perfect fit of the custom-made implant on the site of resection of the bone flap.TECHNICAL NOTEloaded into the navigation system to guide resection duringsurgery. Preoperatively, a custom-made implant was made with a3D-printer, based on the properties of the “resection line” object.Our method has several advantages over other reportedmethods. First, there is no further need to draw a resection lineon a stereolithographic model nor to scan the model since allsteps can be done virtually. This reduces the number ofproduction steps and thus time and costs. Second, navigation-guided resection allows for a fast and precise recreation of thevirtually generated resection line. We did this by using a navi-gated sterile pen; another option would be to connect the228 www.SCIENCEDIRECT.com WORLD NEUoperation microscope to the navigation system and project theimplant or resection line into the microscope. This reducesoperation time, because no adjustments need to be made to theresection margin or the implant itself. Third, the implant wasmanufactured preoperatively, so there was no need to manuallymold an artificial bone flap during surgery.Because the patient-specific model was printed in our 3Dlaboratory, we did not need to collaborate with a commercialmanufacturer. This also greatly reduced the cost of producing theimplant. Momentarily, our workflow is still based on 3D printing astereolithographic model and secondarily creating a PMMAROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177TECHNICAL NOTEimplant, but the methods as presented in this paper wouldperfectly allow immediate printing of implants. We achieved avery satisfying cosmetic result using our method because the fitof the implant was optimal without the need to make furtheradjustments to the implant or the resection margin.The use of 3D printing has become widely available in neuro-surgery,13 specifically in the production of custom-made im-plants.14 However, most case reports and case series presentedin literature describe the use of custom-made implants forreconstructing pre-existing cranial defects, and the use of thistechnique for single-step cranial reconstruction procedures is stillrelatively scarce. Furthermore, there is currently no standard 3Dprinting process for the use in neurosurgical procedures.15 Ourproposed method aims at facilitating this process.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017CONCLUSIONSSingle-step resection and cranioplasty are becoming the stan-dard of care in patients with skull lesions. The use of special-ized software and a navigation system highly facilitate thisprocess. By planning a virtual resection preoperatively andgenerating the resection line as an object that can be loadedinto the navigation system, a precisely navigated resection canbe obtained. Also, based on this object, a custom-made implantis produced before surgery so that the implant fits accuratelyand can be inserted in a single-step procedure. This processensures an optimal fit for the implant while reducingmanufacturing costs and operating time and providing perfectcosmetic results.REFERENCES1. Chen TC. Primary intraosseous meningioma.Neurosurg Clin N Am. 2016;27:189-193.2. Inagaki K, Otsuka F, Matsui T, Ogura T,Makino H. Effect of etidronate on intraosseousmeningioma. Endocr J. 2004;51:389-390.3. Elder JB, Atkinson R, Zee CS, Chen TC. Primaryintraosseous meningioma. Neurosurg Focus. 2007;23:E13.4. Tokgoz N, Oner YA, Kaymaz M, Ucar M,Yilmaz G, Tali TE. Primary intraosseousmeningioma: CT and MRI appearance. AJNR Am JNeuroradiol. 2005;26:2053-2056.5. D’Urso PS, Redmond MJ. A method for theresection of cranial tumours and skull recon-struction. Br J Neurosurg. 2000;14:555-559.6. Bloch O, McDermott MW. In situ cranioplasty forhyperostosing meningiomas of the cranial vault.Can J Neurol Sci. 2011;38:59-64.7. Velnar T, Pregelj R, Limbaeck-Stokin C. Brainmeningioma invading and destructing the skullbone: replacement of the missing bone in vivo.Radiol Oncol. 2011;45:304-309.8. Castle M, Rivero M, Marquez J. Primary Ewing’ssarcoma of the skull: radical resection and im-mediate cranioplasty after chemotherapy. A tech-nical note. Childs Nerv Syst. 2013;29:303-306.9. Saringer W, Nöbauer-Huhmann I, Knosp E.Cranioplasty with individual carbon fibre rein-forced polymere (CFRP) medical grade implantsbased on CAD/CAM technique. Acta Neurochir.2002;144:1193-1203.10. Della Puppa A, Mottaran R, Scienza R. Image-guided cranial osteoma resection and bioceramicporous hydroxyapatite custom-made reconstruc-tion in a one-step surgical procedure. Technicalnotes and illustrative case. Acta Neurochir. 2010;152:155-159.11. Westendorff C, Kaminsky J, Ernemann U, Reinert S,Hoffmann J. Image-guided sphenoid wing menin-gioma resection and simultaneous computer-assisted cranio-orbital reconstruction: technicalcase report. Neurosurgery. 2007;60(2 suppl 1):173-174.12. Jalbert F, Boetto S, Nadon F, Lauwers F,Schmidt E, Lopez R. One-step primary recon-struction for complex craniofacial resection withPEEK custom-made implants. J CraniomaxillofacSurg. 2014;42:141-148.ww13. Tomasello F, Conti A, La Torre D. 3D printing inneurosurgery. World Neurosurg. 2016;91:633-634.14. Bonda DJ, Manjila S, Selman WR, Dean D. Therecent revolution in the design and manufactureof cranial implants: modern advancements andfuture directions. Neurosurgery. 2015;77:814-824.15. Pucci JU, Christophe BR, Sisti JA, Connolly ES Jr.Three-dimensional printing: technologies, appli-cations, and limitations in neurosurgery. BiotechnolAdv. 2017;35:521-529.Conflict of interest statement: The authors declare thatthe article content was composed in the absence of anycommercial or financial relationships that could beconstrued as a potential conflict of interest.Received 27 May 2017; accepted 28 August 2017Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. Allrights reserved.w.WORLDNEUROSURGERY.org 229

Proceedings - University of Groningen

   University of GroningenSingle-Step Resection of an Intraosseous Meningioma and Cranial ReconstructionBroeckx, Charlotte-Elise; Maal, Thomas J. J.; Vreeken, Rinaldo D.; Bos, Ruud R. M.; terLaan, MarkPublished in:World neurosurgeryDOI:10.1016/j.wneu.2017.08.177IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2017Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Broeckx, C-E., Maal, T. J. J., Vreeken, R. D., Bos, R. R. M., & ter Laan, M. (2017). Single-Step Resectionof an Intraosseous Meningioma and Cranial Reconstruction: Technical Note. World neurosurgery, 108,225-229. https://doi.org/10.1016/j.wneu.2017.08.177CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 10-09-2023Technical NoteSingle-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction:Technical NoteCharlotte-Elise Broeckx1, Thomas J.J. Maal2,3, Rinaldo D. Vreeken2,3, Ruud R.M. Bos5, Mark ter Laan4-OBJECTIVE: Simultaneous tumor resection and cranialreconstruction can be a challenging task. Surgical navi-gation is an indispensable tool in making this single-stepprocedure possible. In this technical note, we describe anew technique for this procedure to ensure a preciseresection and optimal fit of the implant in a patient with anintraosseous meningioma.-METHODS: We generated a 3-dimensional (3D) model ofthe patient’s skull based on a computed tomography scanand created a digital “resection line” object using 3DStudio Max 2016 software. Based on this object, thepatient-specific implant was generated and printed with a3D printer. Before surgery, the digital object was trans-ferred to the neuronavigation system to enable a navigatedresection of the lesion to ensure maximum precision.During surgery, the craniotomy was performed, and thecustom-made implant was fitted in a single step.-RESULTS: The planned resection was achieved, and theimplant could be fitted without need for further adjustmentsto the resection border.-CONCLUSIONS: We provide a simple technique todigitally define a planned resection site and create acustom-made implant using specialized software and 3Dprinting to enable single-step resection of a skull lesionand cranial reconstruction, thereby reducing surgical timeand costs and ensuring a good cosmetic result.Key words- 3-Dimensional printing- Cranioplasty- Intraosseous meningioma- PMMA- Single-step procedure- Skull lesionAbbreviations and Acronyms3D: 3-DimensionalCT: Computed tomographyPMMA: Polymethyl methacrylateWORLD NEUROSURGERY 108: 225-229, DECEMBER 2017INTRODUCTIONntraosseous meningiomas of the calvarium present as afirm and painless mass on the skull and may be detectedI incidentally, as neurologic signs and symptoms usually areabsent.1 They can, however, become cosmetically disturbing.Wide surgical excision is potentially curative2 but also leavesthe patient with a skull defect for which a reconstruction isrequired. The rapid evolution of imaging techniques,simulation software, computer-aided reconstruction tech-niques, and surgical navigation have made it possible toperform a resection of the tumor and cranioplasty in a singleprocedure. However, precise definition of the resection site toensure an optimal fit of the implant remains a challenge. Wedescribe a new technique using specialized software to facili-tate this process.CASE REPORTHistoryA 68-year-old woman with a history of diabetes, alcoholichepatitis, and Barrett esophagitis was admitted to the neuro-logic department with diplopia. Analysis showed a vitamin B1deficiency, and complaints resolved with substitution. Imagingalso had shown a lesion of the left frontotemporal skull(Figure 1). Further analysis ruled out a primary tumor elsewhereas well as metastases. A biopsy was scheduled in our centerbecause a malignant lesion was suspected. Biopsy showed aWorld Health Organization grade I intraosseous meningioma,and a watchful waiting strategy was chosen because thepatient was without symptoms. Two years later, progressionof the tumor was shown on magnetic resonance scan(Figure 1), and she opted for surgical resection.From the 1Department of Neurosurgery, University Hospital Leuven, Leuven, Belgium;2Radboudumc 3D Lab, 3Department of Oral and Maxillofacial Surgery, and 4Department ofNeurosurgery, Radboud University Medical Center, Nijmegen, The Netherlands; and5Department of Oral and Maxillofacial Surgery, University of Groningen and UniversityMedical Center Groningen, Groningen, The NetherlandsTo whom correspondence should be addressed: Charlotte-Elise Broeckx, M.D.[E-mail: charlotte-elise.broeckx@uzleuven.be]Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.www.WORLDNEUROSURGERY.org 225Figure 1. Magnetic resonance scan at diagnosis (top) and 2 years later at time of progression (bottom).TECHNICAL NOTEPreoperative PlanningA resection and reconstruction in one session was planned.First, a computed tomography (CT) scan (0.5-mm slices) wastaken (Figure 2). Digital Imaging and Communications inMedicine images were exported to Maxilim, version 2.2.2.1(Medicim NV, Mechelen, Belgium) software, and a3-dimensional (3D) model was reconstructed. In 3D StudioMax 2016 (Autodesk Inc., San Rafael, California, USA), thesurgeon drew a digital resection line on the 3D model, whichwas used to generate a “resection line” object. All 3D datawithin the resection line were excluded from the model; themodel was then copied and mirrored. The mirrored and originalmodels were fused (excluding resection), and the 3D data fromthe projection in the previously defined resection area onthe right side of the skull were used to generate a 3D model ofthe implant.Both the model (with the lesion resected) and the implant designwere 3D printed with a FormLabs Form 2 3D Printer (FormlabsInc., Somerville, Massachusetts, USA). The implant was then226 www.SCIENCEDIRECT.com WORLD NEUmade from polymethyl methacrylate (PMMA) by copying the3D-printed implant design in wax. The wax model wasembedded in plaster and burned out after which the space insidethe plaster was filled with hot cured PMMA. The PMMA implantwas polished, cleaned by brushing with soap, and plasmasterilized.The day before surgery, a new magnetic resonance scan wasperformed, which was loaded into iPlan Brainlab software(Brainlab AG, Munich, Germany) and fused with the thin-slice CT.The 3D images of the implant and resection line were importedinto the software as well (Figure 3).Surgical ProcedureDuring surgery, a reference star was fitted on a sterile markerand registered with the Brainlab system. Via the use of thisnavigated sterile marker, the preoperatively defined resectionborder could be drawn onto the patient’s skull during the sur-gery (Figure 4A). The craniotomy was performed following thisROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177Figure 2. Preoperative, thin-slice computed tomography scan with 3-dimensional reconstruction.TECHNICAL NOTEline. Next, the dura around the tumor was resected, and areconstruction was made with periost. Then, the implantcould be put in place and fixed with titanium screws(Figure 4D). The fit of the implant was as planned, so therewas no need to make further adjustments for improvement.Figure 3. Implant model as imported in Brainlab software.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017DISCUSSIONIntraosseous meningiomas are rare lesions that originate in theskull and constitute fewer than 2% of meningiomas overall.Although most are benign, intraosseous meningiomas are morelikely to be malignant than their intradural counterparts. Thetreatment of choice is wide surgical resection, which is poten-tially curative.3 Ideally, cranial reconstruction should occur as partof the same procedure.4Different techniques have been described to perform a single-step procedure: using a preoperatively produced template,5intraoperatively molding an artificial bone flap without atemplate,6,7 or producing a stereolithographic model to helpguide resection and/or design the custom-made implant. Such amodel can be used to create a template to guide resection,8 or itcan be used to manually create the desired resection to producea custom-made implant based on the defect in the model,9sometimes even requiring the model itself to be scanned andthe images to be fused with the original CT images to createthe planned resection line that can be used by theneuronavigation system.10,11 In some cases, adjustments tothe preoperatively produced implants still need to be made.8,9Digitalization of the process of manufacturing a custom-madeimplant has made it possible to produce accurately fitting im-plants with a minimum of intermediate steps, thus avoidingapproximate reconstructions using conventional techniques or 2-step procedures.12 Surgical navigation is an indispensable tool toensure an optimal fit of the implant.We have described a method to perform a single-step tumorresection and cranioplasty in which the preoperatively plannedresection was performed virtually. With the use of specializedsoftware, a digital “resection line” object was created, which waswww.WORLDNEUROSURGERY.org 227Figure 4. (A) Navigation-guided demarcation of theresection margin. (B) The custom-made implant beforeplacement. (C) Situation after navigation-guidedremoval of the bone flap. (D) Perfect fit of the custom-made implant on the site of resection of the bone flap.TECHNICAL NOTEloaded into the navigation system to guide resection duringsurgery. Preoperatively, a custom-made implant was made with a3D-printer, based on the properties of the “resection line” object.Our method has several advantages over other reportedmethods. First, there is no further need to draw a resection lineon a stereolithographic model nor to scan the model since allsteps can be done virtually. This reduces the number ofproduction steps and thus time and costs. Second, navigation-guided resection allows for a fast and precise recreation of thevirtually generated resection line. We did this by using a navi-gated sterile pen; another option would be to connect the228 www.SCIENCEDIRECT.com WORLD NEUoperation microscope to the navigation system and project theimplant or resection line into the microscope. This reducesoperation time, because no adjustments need to be made to theresection margin or the implant itself. Third, the implant wasmanufactured preoperatively, so there was no need to manuallymold an artificial bone flap during surgery.Because the patient-specific model was printed in our 3Dlaboratory, we did not need to collaborate with a commercialmanufacturer. This also greatly reduced the cost of producing theimplant. Momentarily, our workflow is still based on 3D printing astereolithographic model and secondarily creating a PMMAROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177TECHNICAL NOTEimplant, but the methods as presented in this paper wouldperfectly allow immediate printing of implants. We achieved avery satisfying cosmetic result using our method because the fitof the implant was optimal without the need to make furtheradjustments to the implant or the resection margin.The use of 3D printing has become widely available in neuro-surgery,13 specifically in the production of custom-made im-plants.14 However, most case reports and case series presentedin literature describe the use of custom-made implants forreconstructing pre-existing cranial defects, and the use of thistechnique for single-step cranial reconstruction procedures is stillrelatively scarce. Furthermore, there is currently no standard 3Dprinting process for the use in neurosurgical procedures.15 Ourproposed method aims at facilitating this process.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017CONCLUSIONSSingle-step resection and cranioplasty are becoming the stan-dard of care in patients with skull lesions. The use of special-ized software and a navigation system highly facilitate thisprocess. By planning a virtual resection preoperatively andgenerating the resection line as an object that can be loadedinto the navigation system, a precisely navigated resection canbe obtained. Also, based on this object, a custom-made implantis produced before surgery so that the implant fits accuratelyand can be inserted in a single-step procedure. This processensures an optimal fit for the implant while reducingmanufacturing costs and operating time and providing perfectcosmetic results.REFERENCES1. Chen TC. Primary intraosseous meningioma.Neurosurg Clin N Am. 2016;27:189-193.2. Inagaki K, Otsuka F, Matsui T, Ogura T,Makino H. Effect of etidronate on intraosseousmeningioma. Endocr J. 2004;51:389-390.3. Elder JB, Atkinson R, Zee CS, Chen TC. Primaryintraosseous meningioma. Neurosurg Focus. 2007;23:E13.4. Tokgoz N, Oner YA, Kaymaz M, Ucar M,Yilmaz G, Tali TE. Primary intraosseousmeningioma: CT and MRI appearance. AJNR Am JNeuroradiol. 2005;26:2053-2056.5. D’Urso PS, Redmond MJ. A method for theresection of cranial tumours and skull recon-struction. Br J Neurosurg. 2000;14:555-559.6. Bloch O, McDermott MW. In situ cranioplasty forhyperostosing meningiomas of the cranial vault.Can J Neurol Sci. 2011;38:59-64.7. Velnar T, Pregelj R, Limbaeck-Stokin C. Brainmeningioma invading and destructing the skullbone: replacement of the missing bone in vivo.Radiol Oncol. 2011;45:304-309.8. Castle M, Rivero M, Marquez J. Primary Ewing’ssarcoma of the skull: radical resection and im-mediate cranioplasty after chemotherapy. A tech-nical note. Childs Nerv Syst. 2013;29:303-306.9. Saringer W, Nöbauer-Huhmann I, Knosp E.Cranioplasty with individual carbon fibre rein-forced polymere (CFRP) medical grade implantsbased on CAD/CAM technique. Acta Neurochir.2002;144:1193-1203.10. Della Puppa A, Mottaran R, Scienza R. Image-guided cranial osteoma resection and bioceramicporous hydroxyapatite custom-made reconstruc-tion in a one-step surgical procedure. Technicalnotes and illustrative case. Acta Neurochir. 2010;152:155-159.11. Westendorff C, Kaminsky J, Ernemann U, Reinert S,Hoffmann J. Image-guided sphenoid wing menin-gioma resection and simultaneous computer-assisted cranio-orbital reconstruction: technicalcase report. Neurosurgery. 2007;60(2 suppl 1):173-174.12. Jalbert F, Boetto S, Nadon F, Lauwers F,Schmidt E, Lopez R. One-step primary recon-struction for complex craniofacial resection withPEEK custom-made implants. J CraniomaxillofacSurg. 2014;42:141-148.ww13. Tomasello F, Conti A, La Torre D. 3D printing inneurosurgery. World Neurosurg. 2016;91:633-634.14. Bonda DJ, Manjila S, Selman WR, Dean D. Therecent revolution in the design and manufactureof cranial implants: modern advancements andfuture directions. Neurosurgery. 2015;77:814-824.15. Pucci JU, Christophe BR, Sisti JA, Connolly ES Jr.Three-dimensional printing: technologies, appli-cations, and limitations in neurosurgery. BiotechnolAdv. 2017;35:521-529.Conflict of interest statement: The authors declare thatthe article content was composed in the absence of anycommercial or financial relationships that could beconstrued as a potential conflict of interest.Received 27 May 2017; accepted 28 August 2017Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. Allrights reserved.w.WORLDNEUROSURGERY.org 229

   University of GroningenSingle-Step Resection of an Intraosseous Meningioma and Cranial ReconstructionBroeckx, Charlotte-Elise; Maal, Thomas J. J.; Vreeken, Rinaldo D.; Bos, Ruud R. M.; terLaan, MarkPublished in:World neurosurgeryDOI:10.1016/j.wneu.2017.08.177IMPORTANT NOTE: You are advised to consult the publisher's version (publisher's PDF) if you wish to cite fromit. Please check the document version below.Document VersionPublisher's PDF, also known as Version of recordPublication date:2017Link to publication in University of Groningen/UMCG research databaseCitation for published version (APA):Broeckx, C-E., Maal, T. J. J., Vreeken, R. D., Bos, R. R. M., & ter Laan, M. (2017). Single-Step Resectionof an Intraosseous Meningioma and Cranial Reconstruction: Technical Note. World neurosurgery, 108,225-229. https://doi.org/10.1016/j.wneu.2017.08.177CopyrightOther than for strictly personal use, it is not permitted to download or to forward/distribute the text or part of it without the consent of theauthor(s) and/or copyright holder(s), unless the work is under an open content license (like Creative Commons).The publication may also be distributed here under the terms of Article 25fa of the Dutch Copyright Act, indicated by the “Taverne” license.More information can be found on the University of Groningen website: https://www.rug.nl/library/open-access/self-archiving-pure/taverne-amendment.Take-down policyIf you believe that this document breaches copyright please contact us providing details, and we will remove access to the work immediatelyand investigate your claim.Downloaded from the University of Groningen/UMCG research database (Pure): http://www.rug.nl/research/portal. For technical reasons thenumber of authors shown on this cover page is limited to 10 maximum.Download date: 31-10-2023Technical NoteSingle-Step Resection of an Intraosseous Meningioma and Cranial Reconstruction:Technical NoteCharlotte-Elise Broeckx1, Thomas J.J. Maal2,3, Rinaldo D. Vreeken2,3, Ruud R.M. Bos5, Mark ter Laan4-OBJECTIVE: Simultaneous tumor resection and cranialreconstruction can be a challenging task. Surgical navi-gation is an indispensable tool in making this single-stepprocedure possible. In this technical note, we describe anew technique for this procedure to ensure a preciseresection and optimal fit of the implant in a patient with anintraosseous meningioma.-METHODS: We generated a 3-dimensional (3D) model ofthe patient’s skull based on a computed tomography scanand created a digital “resection line” object using 3DStudio Max 2016 software. Based on this object, thepatient-specific implant was generated and printed with a3D printer. Before surgery, the digital object was trans-ferred to the neuronavigation system to enable a navigatedresection of the lesion to ensure maximum precision.During surgery, the craniotomy was performed, and thecustom-made implant was fitted in a single step.-RESULTS: The planned resection was achieved, and theimplant could be fitted without need for further adjustmentsto the resection border.-CONCLUSIONS: We provide a simple technique todigitally define a planned resection site and create acustom-made implant using specialized software and 3Dprinting to enable single-step resection of a skull lesionand cranial reconstruction, thereby reducing surgical timeand costs and ensuring a good cosmetic result.Key words- 3-Dimensional printing- Cranioplasty- Intraosseous meningioma- PMMA- Single-step procedure- Skull lesionAbbreviations and Acronyms3D: 3-DimensionalCT: Computed tomographyPMMA: Polymethyl methacrylateWORLD NEUROSURGERY 108: 225-229, DECEMBER 2017INTRODUCTIONntraosseous meningiomas of the calvarium present as afirm and painless mass on the skull and may be detectedI incidentally, as neurologic signs and symptoms usually areabsent.1 They can, however, become cosmetically disturbing.Wide surgical excision is potentially curative2 but also leavesthe patient with a skull defect for which a reconstruction isrequired. The rapid evolution of imaging techniques,simulation software, computer-aided reconstruction tech-niques, and surgical navigation have made it possible toperform a resection of the tumor and cranioplasty in a singleprocedure. However, precise definition of the resection site toensure an optimal fit of the implant remains a challenge. Wedescribe a new technique using specialized software to facili-tate this process.CASE REPORTHistoryA 68-year-old woman with a history of diabetes, alcoholichepatitis, and Barrett esophagitis was admitted to the neuro-logic department with diplopia. Analysis showed a vitamin B1deficiency, and complaints resolved with substitution. Imagingalso had shown a lesion of the left frontotemporal skull(Figure 1). Further analysis ruled out a primary tumor elsewhereas well as metastases. A biopsy was scheduled in our centerbecause a malignant lesion was suspected. Biopsy showed aWorld Health Organization grade I intraosseous meningioma,and a watchful waiting strategy was chosen because thepatient was without symptoms. Two years later, progressionof the tumor was shown on magnetic resonance scan(Figure 1), and she opted for surgical resection.From the 1Department of Neurosurgery, University Hospital Leuven, Leuven, Belgium;2Radboudumc 3D Lab, 3Department of Oral and Maxillofacial Surgery, and 4Department ofNeurosurgery, Radboud University Medical Center, Nijmegen, The Netherlands; and5Department of Oral and Maxillofacial Surgery, University of Groningen and UniversityMedical Center Groningen, Groningen, The NetherlandsTo whom correspondence should be addressed: Charlotte-Elise Broeckx, M.D.[E-mail: charlotte-elise.broeckx@uzleuven.be]Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. All rights reserved.www.WORLDNEUROSURGERY.org 225Figure 1. Magnetic resonance scan at diagnosis (top) and 2 years later at time of progression (bottom).TECHNICAL NOTEPreoperative PlanningA resection and reconstruction in one session was planned.First, a computed tomography (CT) scan (0.5-mm slices) wastaken (Figure 2). Digital Imaging and Communications inMedicine images were exported to Maxilim, version 2.2.2.1(Medicim NV, Mechelen, Belgium) software, and a3-dimensional (3D) model was reconstructed. In 3D StudioMax 2016 (Autodesk Inc., San Rafael, California, USA), thesurgeon drew a digital resection line on the 3D model, whichwas used to generate a “resection line” object. All 3D datawithin the resection line were excluded from the model; themodel was then copied and mirrored. The mirrored and originalmodels were fused (excluding resection), and the 3D data fromthe projection in the previously defined resection area onthe right side of the skull were used to generate a 3D model ofthe implant.Both the model (with the lesion resected) and the implant designwere 3D printed with a FormLabs Form 2 3D Printer (FormlabsInc., Somerville, Massachusetts, USA). The implant was then226 www.SCIENCEDIRECT.com WORLD NEUmade from polymethyl methacrylate (PMMA) by copying the3D-printed implant design in wax. The wax model wasembedded in plaster and burned out after which the space insidethe plaster was filled with hot cured PMMA. The PMMA implantwas polished, cleaned by brushing with soap, and plasmasterilized.The day before surgery, a new magnetic resonance scan wasperformed, which was loaded into iPlan Brainlab software(Brainlab AG, Munich, Germany) and fused with the thin-slice CT.The 3D images of the implant and resection line were importedinto the software as well (Figure 3).Surgical ProcedureDuring surgery, a reference star was fitted on a sterile markerand registered with the Brainlab system. Via the use of thisnavigated sterile marker, the preoperatively defined resectionborder could be drawn onto the patient’s skull during the sur-gery (Figure 4A). The craniotomy was performed following thisROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177Figure 2. Preoperative, thin-slice computed tomography scan with 3-dimensional reconstruction.TECHNICAL NOTEline. Next, the dura around the tumor was resected, and areconstruction was made with periost. Then, the implantcould be put in place and fixed with titanium screws(Figure 4D). The fit of the implant was as planned, so therewas no need to make further adjustments for improvement.Figure 3. Implant model as imported in Brainlab software.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017DISCUSSIONIntraosseous meningiomas are rare lesions that originate in theskull and constitute fewer than 2% of meningiomas overall.Although most are benign, intraosseous meningiomas are morelikely to be malignant than their intradural counterparts. Thetreatment of choice is wide surgical resection, which is poten-tially curative.3 Ideally, cranial reconstruction should occur as partof the same procedure.4Different techniques have been described to perform a single-step procedure: using a preoperatively produced template,5intraoperatively molding an artificial bone flap without atemplate,6,7 or producing a stereolithographic model to helpguide resection and/or design the custom-made implant. Such amodel can be used to create a template to guide resection,8 or itcan be used to manually create the desired resection to producea custom-made implant based on the defect in the model,9sometimes even requiring the model itself to be scanned andthe images to be fused with the original CT images to createthe planned resection line that can be used by theneuronavigation system.10,11 In some cases, adjustments tothe preoperatively produced implants still need to be made.8,9Digitalization of the process of manufacturing a custom-madeimplant has made it possible to produce accurately fitting im-plants with a minimum of intermediate steps, thus avoidingapproximate reconstructions using conventional techniques or 2-step procedures.12 Surgical navigation is an indispensable tool toensure an optimal fit of the implant.We have described a method to perform a single-step tumorresection and cranioplasty in which the preoperatively plannedresection was performed virtually. With the use of specializedsoftware, a digital “resection line” object was created, which waswww.WORLDNEUROSURGERY.org 227Figure 4. (A) Navigation-guided demarcation of theresection margin. (B) The custom-made implant beforeplacement. (C) Situation after navigation-guidedremoval of the bone flap. (D) Perfect fit of the custom-made implant on the site of resection of the bone flap.TECHNICAL NOTEloaded into the navigation system to guide resection duringsurgery. Preoperatively, a custom-made implant was made with a3D-printer, based on the properties of the “resection line” object.Our method has several advantages over other reportedmethods. First, there is no further need to draw a resection lineon a stereolithographic model nor to scan the model since allsteps can be done virtually. This reduces the number ofproduction steps and thus time and costs. Second, navigation-guided resection allows for a fast and precise recreation of thevirtually generated resection line. We did this by using a navi-gated sterile pen; another option would be to connect the228 www.SCIENCEDIRECT.com WORLD NEUoperation microscope to the navigation system and project theimplant or resection line into the microscope. This reducesoperation time, because no adjustments need to be made to theresection margin or the implant itself. Third, the implant wasmanufactured preoperatively, so there was no need to manuallymold an artificial bone flap during surgery.Because the patient-specific model was printed in our 3Dlaboratory, we did not need to collaborate with a commercialmanufacturer. This also greatly reduced the cost of producing theimplant. Momentarily, our workflow is still based on 3D printing astereolithographic model and secondarily creating a PMMAROSURGERY, http://dx.doi.org/10.1016/j.wneu.2017.08.177TECHNICAL NOTEimplant, but the methods as presented in this paper wouldperfectly allow immediate printing of implants. We achieved avery satisfying cosmetic result using our method because the fitof the implant was optimal without the need to make furtheradjustments to the implant or the resection margin.The use of 3D printing has become widely available in neuro-surgery,13 specifically in the production of custom-made im-plants.14 However, most case reports and case series presentedin literature describe the use of custom-made implants forreconstructing pre-existing cranial defects, and the use of thistechnique for single-step cranial reconstruction procedures is stillrelatively scarce. Furthermore, there is currently no standard 3Dprinting process for the use in neurosurgical procedures.15 Ourproposed method aims at facilitating this process.WORLD NEUROSURGERY 108: 225-229, DECEMBER 2017CONCLUSIONSSingle-step resection and cranioplasty are becoming the stan-dard of care in patients with skull lesions. The use of special-ized software and a navigation system highly facilitate thisprocess. By planning a virtual resection preoperatively andgenerating the resection line as an object that can be loadedinto the navigation system, a precisely navigated resection canbe obtained. Also, based on this object, a custom-made implantis produced before surgery so that the implant fits accuratelyand can be inserted in a single-step procedure. This processensures an optimal fit for the implant while reducingmanufacturing costs and operating time and providing perfectcosmetic results.REFERENCES1. Chen TC. Primary intraosseous meningioma.Neurosurg Clin N Am. 2016;27:189-193.2. Inagaki K, Otsuka F, Matsui T, Ogura T,Makino H. Effect of etidronate on intraosseousmeningioma. Endocr J. 2004;51:389-390.3. Elder JB, Atkinson R, Zee CS, Chen TC. Primaryintraosseous meningioma. Neurosurg Focus. 2007;23:E13.4. Tokgoz N, Oner YA, Kaymaz M, Ucar M,Yilmaz G, Tali TE. Primary intraosseousmeningioma: CT and MRI appearance. AJNR Am JNeuroradiol. 2005;26:2053-2056.5. D’Urso PS, Redmond MJ. A method for theresection of cranial tumours and skull recon-struction. Br J Neurosurg. 2000;14:555-559.6. Bloch O, McDermott MW. In situ cranioplasty forhyperostosing meningiomas of the cranial vault.Can J Neurol Sci. 2011;38:59-64.7. Velnar T, Pregelj R, Limbaeck-Stokin C. Brainmeningioma invading and destructing the skullbone: replacement of the missing bone in vivo.Radiol Oncol. 2011;45:304-309.8. Castle M, Rivero M, Marquez J. Primary Ewing’ssarcoma of the skull: radical resection and im-mediate cranioplasty after chemotherapy. A tech-nical note. Childs Nerv Syst. 2013;29:303-306.9. Saringer W, Nöbauer-Huhmann I, Knosp E.Cranioplasty with individual carbon fibre rein-forced polymere (CFRP) medical grade implantsbased on CAD/CAM technique. Acta Neurochir.2002;144:1193-1203.10. Della Puppa A, Mottaran R, Scienza R. Image-guided cranial osteoma resection and bioceramicporous hydroxyapatite custom-made reconstruc-tion in a one-step surgical procedure. Technicalnotes and illustrative case. Acta Neurochir. 2010;152:155-159.11. Westendorff C, Kaminsky J, Ernemann U, Reinert S,Hoffmann J. Image-guided sphenoid wing menin-gioma resection and simultaneous computer-assisted cranio-orbital reconstruction: technicalcase report. Neurosurgery. 2007;60(2 suppl 1):173-174.12. Jalbert F, Boetto S, Nadon F, Lauwers F,Schmidt E, Lopez R. One-step primary recon-struction for complex craniofacial resection withPEEK custom-made implants. J CraniomaxillofacSurg. 2014;42:141-148.ww13. Tomasello F, Conti A, La Torre D. 3D printing inneurosurgery. World Neurosurg. 2016;91:633-634.14. Bonda DJ, Manjila S, Selman WR, Dean D. Therecent revolution in the design and manufactureof cranial implants: modern advancements andfuture directions. Neurosurgery. 2015;77:814-824.15. Pucci JU, Christophe BR, Sisti JA, Connolly ES Jr.Three-dimensional printing: technologies, appli-cations, and limitations in neurosurgery. BiotechnolAdv. 2017;35:521-529.Conflict of interest statement: The authors declare thatthe article content was composed in the absence of anycommercial or financial relationships that could beconstrued as a potential conflict of interest.Received 27 May 2017; accepted 28 August 2017Citation: World Neurosurg. (2017) 108:225-229.http://dx.doi.org/10.1016/j.wneu.2017.08.177Journal homepage: www.WORLDNEUROSURGERY.orgAvailable online: www.sciencedirect.com1878-8750/$ - see front matter ª 2017 Elsevier Inc. Allrights reserved.w.WORLDNEUROSURGERY.org 229

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Önsel Türk, Uğur

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