Titanium mesh cranioplasty for patients with large cranial defects ...

456 Bogris Elephterios et al Titanium mesh cranioplasty for patients with cranial defectsTitanium mesh cranioplasty for patients with large cranialdefects – technical notesBogris Elephterios 1 , N. Dobrin 2 , A. Chiriac 21 “Gr.T. Popa” University of Medicine and Pharmacy, Iasi2 Emergency Clinical Hospital “Prof. Dr. N. Oblu”, Neurosurgery Department, IasiAbstractWe propose to describe some personalpoints of view concerning the repair oflarge cranial defects using titanium mesh,and in this sense we present few cases. Alsowe expose the presurgical planning by 3Dimaging acquisition with the radiologicdigital system which allow a computeraided design for a precise measurement ofthe shape and the curvature of cranialdefect.Keywords: cranioplasty, titanium,computer-aided design, skull defectsIntroductionThere are a lot of pathological processeswith involve the cranium including calvarialand skull base anatomical regions, traumaticdefects, congenital, iatrogenic injuries,septic and all this processes leave thecranial defects exposing in this manner thebrain with the soft covers, dura mater andthe skin layers and also the imperfection ofthe skull shape induce important variationsin intracranial pressure especially inpositional movements orto-clinostatism.We insist on the aesthetic aspect becausethese large defects have also an importantcosmetic impact. Titanium (Ti22) wasdiscovered in 1791 by William Gregor inEngland and is a soft metal, very resistant tocorrosion, used in various alloys of iron,vanadium, aluminum, etc. Titanium is usedespecially in aerospace, military andincreasingly more in medical prosthetics.Characteristic of this metal is the ratiostrength / weight, pure titanium (unalloyed)has greater resistance to the same strengthas steel and 45% less mass, so it is a softmetal, very resistant to mechanical forcesand fully biocompatible and corrosionresistant. These properties make thematerial of choice today in cranial andspinal prosthesis.Clinical casesWe simply want to show some casesadmitted in our hospital with diversecranial pathology who had bone defects ofvarying sizes and lack of bone that wassolved by implantation of titanium meshprosthesis .Case 1. M. 25 yrs. Admitted after a headtrauma with parieto occipital bilateral brainlaceration with multiple comminutingfractures. In the first time the acute traumasurgery was needed and in the second timethe cranial defects were corrected bytitanium implants. We must emphasize thatwe have developed a preimplantationrotational 3D CT to assess the lack of bonesize and curvature radius of the head andthen, post implantation we realize a 3Dverification to appreciate the correctposition of prosthesis and its connection to

Romanian Neurosurgery (2010) XVII 4: 456 – 460 457the plate bone by titanium screws. Thistechnique was performed with SIEMENSAXIOM ARTIS system in a acquisition 3Drotational protocol with 60frames /sec on 20seconds that means about 1000 frameswhich need reconstruction in specialsoftware . Figure 1, Figure 2Case 2. F 38 yrs. Admitted after multipleintervention for septic problems, subduralempiema and osteitis with frontosinusalorigin, presented three large cranialpostoperative defects.The correction intervention was madeafter 4 years from the septic episode aftercontrolling the septic problems, imagingrevealed that the risk is practically null.Underwent anterior eradication of septicfoci, 3D exploration highlights accuratelywhether or not there are septic risk. Figures3, 4, 5, 6, 7.Figure 1, 2 3D aspects pre and post implants

458 Bogris Elephterios et al Titanium mesh cranioplasty for patients with cranial defectsFigures 3, 4, 5, 6, 7 first image present thepreoperative aspect the others reveals the correctinsertion of titanium prosthesis mesh and screws andalso is the inside view to appreciate the endocraniumDiscussionsThe titanium is considerate the mostcompatible metal and can be easy integratedin the human body. Its biocompatibilitymake it the election material in jointreplacement, dental and craniofacialimplants. Usual the titanium is alloyed withaluminium or vanadium.An interesting property of titanium isthe possibility to osseointegrate in this waythere are prosthesis from titanium migratedwith osteogenic substances (polyvinyl lacticacid) in PLASMA spray.Another property of titanium is thespecial radiolucency so the nonferromagnetic capacity permit the safeexamination in MRI high field, useful forlong term follow-up of the patients.It should be added that very importantthat the properties titanium is compatiblewith MRI exploration (not ferromagnetic)and does not induce any major artifactsexploring the CT or MRI, by providingsuch accurate postoperative imaging(radiolucent). Osseous defects of varioussizes and forms can be solved by attachingautologous bone fragments fixed withtitanium plates and screws. It also showsthat titanium plate are also elastic and hasresistance well calculated to allow easyintraoperative modeling, establishappropriate curvature of the head.

Romanian Neurosurgery (2010) XVII 4: 456 – 460 459Figures 9, 10 Titanium dynamic meshprosthesis covers the whole area and isperfectly connected between bone and thebasal region of bifrontal convexity.Figure 8 Some aspects of the devices used duringsurgery sites. The fitting skull comes with specialdrills for every type of screw sizes and can controlthe insertion depth of boneFigure 9 intraoperative aspectConclusionsIn the neurosurgical pathology there aremany processes that interested the brainand bone shell, for various reasons(postsurgical, traumatic, post-replacementprocess), require resection with restorationper primam or a subsequent time forremaining defect.There are several principles: the implantmust be stable, resistant to daily activitiesand possibly minor injuries, to effectivelyprotect the brain, not skid spontaneous, tobe perfectly biocompatible, does notinterfere with voucher skin vasculature andnot least to make a adequate cosmeticcorrection.Now there are a variety of biomaterialsthat meet these goals. Of all the titaniumsite is best suited for cranioplasty . Surgicalprocedure is relatively simple but requires awell set up infrastructure and obviously adegree of skill. Basically so far I have notreported immediate or delayedcomplications. Is it true that high prices areoften prohibitive, but the cost-effectiveness,ease of implantation process, significantlyreducing operator time and duration ofhospital stay makes it preferable.Figure 10 intraoperative aspectResearch NewsAfter Fraunhofer Institute forManufacturing and Advanced MaterialsIFAM, September 2010, a new titaniumbased material a foam like structure wascreated to replace injured bones. This newform of titanium presentation in medicalpractice will open a lot of possibility, in

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