Injury, Int. J. Care Injured 46 (2015) 80–85
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
3-D titanium mesh reconstruction of defective skull after frontal craniectomy in traumatic brain injury Shuo-Tsung Chen a, Cheng-Jen Chang b, Wei-Chin Su d, Lin-Wan Chang d, I-Hsuan Chu d, Muh-Shi Lin c,d,e,* a
Department of Mathematics, Tunghai University, Taichung, Taiwan Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan Department of Surgery, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan d Department of Neurosurgery, Taipei City Hospital, Zhong Xiao Branch, Taipei, Taiwan e Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan b c
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 25 September 2014
Introduction: Decompressive craniectomy (DC) is a treatment strategy used to reduce intracranial pressure in patients with traumatic brain injuries. However, this procedure has a number of shortcomings, such as excessive sinking of the skin flap, which can lead to cerebral compromise and negatively affect the appearance of the patient. The reconstruction of skull defects has been proposed as a means to overcome these disadvantages. Few previous studies have reported the reconstruction of frontal skull defects using titanium mesh. The aim of this study was to provide a comprehensive review of aesthetic and surgical outcomes associated with this procedure and to list the complications encountered during the repair of frontal skull defects using three-dimensional (3-D) titanium mesh. Methods: A retrospective review was conducted using records from seven adult patients (32–60 years of age) who received titanium mesh implants at a university hospital in Taiwan between January 2011 and June 2012. Aesthetic outcomes, the function of cranial nerves V and VII, and complications (hardware extrusions, meningitis, osteomyelitis, brain abscess, and pneumocephalus) were evaluated. Results: An algorithm capable of accounting for bifrontal skull defects and median bone ridges was developed to improve computer-assisted design/manufacturing (CAD/CAM) of one-piece 3-D titanium mesh implants, thereby making it possible to repair bifrontal skull defects in a single operation. Following this procedure, aesthetic and functional outcomes were excellent and the implants in all patients appeared stable. However, extended healing times in two of the patients resulted in subclinical infections, which were resolved by administering antibiotics over a period of 2 weeks. No patients suffered trigeminal or facial dysfunction. Conclusions: Our findings support the use of 3-D titanium mesh in frontal skull reconstruction. Few complications were encountered, the contours of the forehead were faithfully rendered, and the cosmetic appearance of patients was excellent. For patients with bifrontal skull defects, the use of onepiece implants in a single operation provides numerous advantages over conventional staged surgeries. This application helps to reduce operating time, which is particularly beneficial for elderly patients and those requiring bifrontal cranioplasties. ß 2014 Elsevier Ltd. All rights reserved.
Keywords: Frontal intracranial haemorrhage Head injury Decompressive craniectomy Three-dimensional titanium mesh Reconstruction Cosmesis Quality of life
Introduction Following decompressive craniectomy (DC), some patients with skull bone defects develop a sunken or flattened skin flap
* Corresponding author at: Department of Neurosurgery, Number 87, Tongde Road, Nangang District, Taipei City 115, Taiwan. Tel.: +886 2 27861288; fax: +886 2 27888492. E-mail address: [email protected] (M.-S. Lin). http://dx.doi.org/10.1016/j.injury.2014.09.019 0020–1383/ß 2014 Elsevier Ltd. All rights reserved.
(i.e., trephined syndrome). This complication is particularly prevalent among the elderly [1]. Excessive sinking of the skin flap can result in local compression, which can in turn disturb brain autoregulation and compromise cerebral haemodynamic status [2,3]. However, this dire situation can be avoided by reconstructing skull defects. Cranioplasty plays a critical role in protecting intracranial content from exposure and compression (from atmospheric pressure) and also helps to correct disfigurement [4]. Following cranioplasty, many patients with ‘‘syndrome of the
S.-T. Chen et al. / Injury, Int. J. Care Injured 46 (2015) 80–85
trephined’’ present a deterioration in neurological status [5]. It appears that clinical improvements following cranioplasty may be due to the restoration of normal brain anatomy, cerebral reexpansion, and recovery of normal scalp flap curvature [5]. Various techniques and materials have been used in the repair of skull defects following DC, such as autogenous bone grafts and xenogenetic or alloplastic implants [1,6–10]. Considerable advances have been made in computer-assisted design/manufacturing (CAD/ CAM) to improve the quality of implants. A number of studies have reported the effectiveness of three-dimensional (3-D) CAD/CAM implants in craniofacial skeletal reconstruction with regard to improved cosmesis and fewer complications, compared to conventional autogenous or alloplastic bone, particularly in patients with large skull defects [4,11–13]. Most previous studies on the use of CAD/CAM-fabricated implants have focused on the repair of skull defects following fronto-temporo-parietal (F-T-P) DC (standard trauma craniectomy) [4,11,14]. For example, we previously presented a quantitative analysis of craniofacial symmetry based on the cranial index of symmetry (CIS) following craniofacial skeletal reconstructions using polymethyl methacrylate (PMMA) [1] and titanium cranioplasty [15]. However, little is currently known about the use of CAD/CAM-fabricated implants in the repair of skull defects following frontal DC. This study reviewed the results of seven patients who underwent frontal craniectomy (three unilateral and four bifrontal) using 3-D titanium mesh implants in our institution. Specifically, a one-piece titanium mesh was used to cover bifrontal skull defects and the frontal median bone ridge as an alternative to conventional methods applied bilaterally using multiple implants. Materials and methods Patients Between January 2011 and June 2012, seven consecutive patients aged 32–60 years with severe head injuries and frontal intracranial hematomas were treated in our institution. All patients presented pronounced neurological deficits and
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underwent cranial decompressive surgery. Operative methods included a bicoronal scalp flap and frontal DC to remove a haematoma on one side (n = 3) or both sides (n = 4). In patients with unifrontal DCs, a bicoronal skin flap was implemented and frontal bones on the lesioned side were removed. In cases of bifrontal DC, we bilaterally removed the frontal bones and preserved a frontal median bone ridge (single arrow in Fig. 3E) over the superior sagittal sinus to prevent bleeding [16]. All seven patients appeared physically and neurologically stable at an average of 1.8 months postcraniectomy, whereupon they underwent cranioplasty using seven 3-D titanium mesh implants. Three patients with a unifrontal skull defect underwent unilateral cranioplasty on the lesioned side. Four patients with bifrontal skull defects underwent a bilateral cranioplasty using a one-piece 3-D titanium mesh that provided bilateral coverage over both sides (Fig. 1). 3-D titanium mesh design Brain computed tomographic (CT) scans and CAD/CAM of 3-D titanium mesh for F-T-P skull defects were as described in our previous study [15]. Briefly, each patient received a CT scan on the area of the brain representing a slice (1.25 mm thick) from the base of the skull to convexity (including the region of the skull defect). These high-resolution CT images were then transferred to Medtronic (Golenta, CA, USA) for use in the 3-D CAD design of skull segments. Image-editing software was used to extract digital information from the CT scans, which in turn guided the reconstruction of the contours of area(s) containing skull defects. Contour reconstruction had to account for bilateral frontal skull defects and frontal median bone ridges in patients who had undergone bifrontal DCs (arrow in Fig. 2E and F). The symmetry of the reconstructed contours and their relationship with existing skull bone were simultaneously investigated from axial, coronal, and sagittal views (Fig. 2A, B, E and F). We observed the 3-D CAD reconstruction of artificial flaps and cranial segments using an image-editing software in order to evaluate implants in terms of external appearance and symmetry (Fig. 2C, D, G and H).
Fig. 1. Representative photographs of TBI patients before and after titanium mesh reconstruction. (A–D) Case 1, unifrontal DC; (E–H) Case 2, bifrontal DC. (A) Preoperative CT scan revealing a fracture in which bone fragments separated intraparenchymally at the left frontal lobe. (E) Preoperative CT scan revealing acute bifrontal intracerebral haemorrhage with significant mass effects. (B and F) Depression appearing on the patient’s forehead following DC. The appearance of a patient’s forehead after cranioplasty using 3-D CAD/CAM-fabricated titanium mesh at 30 days (C, G) and 2 years (D, H) postoperatively.
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Fig. 2. Editing 2-D images of brain CT scans and 3-D CAD reconstruction of frontal skull defects. (A–D) Case 1, unilateral skull defect; (E–H) Case 2, bifrontal skull defect. Reconstructed contour of skull defect was generated and simultaneously observed via axial (A, E), and coronal (B, F) views. Image of 3-D reconstruction shows frontal skull defect (C, G) and reconstructed artificial flap (blue colour) (D, H). External appearance and symmetry of 3-D CAD reconstructions can be checked simultaneously. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.)
CAD data were then transferred to a CAM system, in which the final implant (Fig. 3B, F) was stamp-moulded. The 3-D titanium mesh was evaluated and formally approved by the manufacturer. In addition, physicians verified labelled margins, skull defects, and flap contours (triple arrow in Fig. 3F) prior to performing cranioplasty. The titanium mesh used in all of the patients had a standard uniform thickness of 0.6 mm. For patients with bifrontal DCs, this was sufficiently thin to ensure that the titanium mesh overlapped the frontal median bone ridge with no visible deformities. Operating procedures for 3-D titanium mesh cranioplasty to treat frontal skull defects A single dose of 1 g cefazolin was administered intravenously within 60 min prior to cranioplasty [17]. The frontobasal region was exposed through a previous incision, and the scalp was dissected and reflected to expose a region extending beyond the skull defect. The subgaleal space of the scalp was dissected to release any tension that might occur during wound closure. The tissue above the periosteum (epidural space) was also reflected. Approaching the epidural space, leakage of cerebrospinal fluid (CSF) was avoided by taking care to avoid dural tearing. An intact arachnoid membrane (double arrow in Fig. 3E) was also necessary to prevent CSF leakage. The titanium mesh was designed to be anchored epidurally in order to cover all skull defects. Thus, the periosteum and soft tissue around the margins of the skull defects had to be completely removed (arrow in Fig. 3A) in order to enhance implant reduction. Dural tenting sutures with central and circumferential placement were used to eliminate any dead space between the dura and implant (arrow in Fig. 3B and double arrow in Fig. 3F). Following complete hemostasis, the titanium mesh was set in place over the skull defects. (To ensure accurate positioning, the margins of the skull defects had been previously marked on the titanium mesh
(triple arrow in Fig. 3F).) The titanium mesh was anchored in place using 4- or 5-mm screws. Upon stabilising the mesh, the periosteum and soft tissues were tacked in place using suspensory 3/0 Vicryl sutures with the aim of restoring the original anatomy (single arrow in Fig. 3B and F). One or two Jackson–Pratt drains were then emplaced near the frontal base above the titanium mesh to facilitate blood drainage. The galeal layer was closed using multiple interrupted 2/0 Vicryl sutures and the skin was closed using interrupted mattress nylon sutures. Careful alignment of the skin edges was essential to achieve aesthetically pleasing and functional results. Finally, a sterile head dressing was placed over the entire area and held in place until the sutures were removed at 10 days postoperatively. The Jackson–Pratt drains were left in place until drainage was negligible, for a minimum of 2 days after surgery. Outcome measures Cosmesis Aesthetic results were based on postoperative reconstruction radiographs and feedback from the patient and/or the patient’s family. For this feedback, patients or family members evaluated gross external appearance pre- and postcranioplasty using a fourpoint scale, in which 0 indicated no deformity, 1 indicated mild deformity, 2 indicated moderate deformity, and 3 indicated severe deformity [6]. Evaluation of pain Pain was evaluated using a 10-point visual analogue scale (VAS). Patients were required to mark a point on the VAS to indicate the intensity of pain they were experiencing, with 0 indicating no pain and 10 indicating the worst possible pain. Evaluation of cranial nerve Trigeminal nerve function (cranial nerve V) was graded using a three-point semiquantitative scale [6,18], and facial nerve function
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Fig. 3. Representative intraoperative and postoperative computed tomography (CT) images of patients. (A–D) Case 1, unifrontal skull defect; (E–H) Case 2, bifrontal skull defect. Intraoperative exposure of skull defects unilaterally (A) and bilaterally (E) with the preservation of a frontal median bone ridge (single arrow in 3 E). (B and F) CAD/CAM titanium implants for the reconstruction of skull defects. A one-piece titanium mesh was used for the reconstruction of bifrontal skull defects (F). Postoperative axial (C and G) and coronal (D and H) CT scan after reconstruction with titanium mesh showing good symmetry.
(cranial nerve VII) was graded using the six-point House– Brackmann grading system [19]. Complications Data related to complications, such as infection and persistent headache, as well as intracranial complications such as meningitis, brain abscesses, CSF leaks, mucopyocele, and hardware extrusions, were recorded. Complications that occurred within 30 days of cranioplasty were considered postoperative complications. Statistical analysis Descriptive statistics was used to describe the demographic characteristics of the patients. Continuous data are shown as the mean standard deviation (SD), while categorical data are represented by number (n) and percentage (%). Statistical analysis was performed using SPSS 15.0 software (SPSS Inc., Chicago, IL, USA). Results Patient characteristics Between January 2011 and June 2012, seven consecutive patients with major head trauma underwent craniofacial skeletal reconstruction. This group included five males and two females with a mean age of 47.43 10.86 years (range 32–60 years). The cause of traumatic brain injury (TBI) included falls (n = 3), motor vehicle accidents (n = 3), and impacts (n = 1). The average time between cranioplasty and craniectomy was 1.8 months. Three patients required unifrontal cranioplasty and four required bifrontal cranioplasty. The four patients who underwent bifrontal cranioplasty did so during a single operation using a one-piece 3-D titanium mesh, which completely covered the bifrontal skull defects. The mean operating time for skin to skin was 116.1 22.84 min (range of 93– 161 min); the average blood loss was 257.3 mL (range of 50–470 mL); and the mean duration of follow-up was 28.57 4.791 months (range of 19–33 months).
Cosmesis Among the seven patients, five recovered to Glasgow Coma Scale (GCS) score 15 and received Glasgow Outcome Scale (GOS) scores of 4 or 5 (before and after cranioplasties). These five fully conscious patients and the families of the two other patients completed the evaluation of cosmetic outcomes. Grades awarded by patients and families were based on the gross external appearance of the skull before and after cranioplasty. All seven patients received a grade of 0 (no deformity) for the forehead contour after surgery. In addition, we evaluated aesthetic outcomes using postoperative reconstruction radiographs. All postoperative CT images showed good reconstruction of skull defects (Fig. 3D, E, G and H). Extent of pain The five fully conscious patients were also candidates for VAS evaluation. Two of the five patients complained of postoperative pain in the area of the procedure, which necessitated the use of controlled analgesics (patient-controlled analgesia, PCA). The other patients controlled postoperative scalp pain by taking oral analgesics three times per day for 3 days. All five patients had a VAS score of 0; that is, they felt no pain by postoperative day 5 (POD). At follow-up clinic visits, the five patients were asked whether they took analgesics for pain specific to the procedure before obtaining a final VAS score. The final VAS score at a mean follow-up of almost 29 months was 0. Cranial nerve function Compared with preoperative facial sensation, the five fully conscious patients presented no change in the function of cranial nerve V. Furthermore, all seven of the patients had normal symmetrical facial nerve function in all areas (Grade 1). Complications The healing of incisions in two patients with type 1 diabetes was delayed, resulting in subsequent subclinical infection, which
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was resolved following 2 weeks of antibiotic treatment. The two patients received nonsurgical interventions (wound debridement), which resulted in complete healing, showing no sign of deterioration throughout the follow-up period of nearly 29 months. To date, no instances of implant extrusion or intracranial complications, including persistent headaches, meningitis, osteomyelitis, brain abscesses, CSF leaks, pneumocephalus, or mucopyocele, have been reported among any of the seven patients in long-term follow-up. Discussion In this study, we conducted a retrospective review of seven patients with head trauma who underwent DC and the reconstruction of defective frontal skulls using 3-D CAD/CAM-derived titanium mesh implants. Following implantation, the aesthetic, radiological, and functional outcomes of all patients were good. Postoperative complications, such as wound pain and infection, were similar to those previously reported in the F-T-P region [15], and no other serious postoperative complications were encountered. At the present mean follow-up of nearly 29 months (range 19–33 months), no headaches, wound infections, or intracranial/ hardware complications have been noted. These results demonstrate the safety, stability, and practicality of reconstruction techniques for the repair of frontal skull defects. Specifically, the current study evaluated the use of 3-D titanium mesh in bifrontal cranioplasties. The highlights of this study are as follows: (1) The proposed CAD/CAM model includes algorithms and techniques to provide seamless coverage of bifrontal skull defects and the median ridge by reconstructing the original contours of the skull. (2) The extreme thinness of the implant (6 mm) renders it essentially indistinguishable from the original bone. (3) The use of one-piece 3-D titanium mesh devices makes it possible to perform cranioplasties on both sides of the skull in a single operation. Although the sample size was small in this study, we have nonetheless demonstrated the clinical efficacy of the procedure. Frontal intracranial hematomas in TBI patients have raised concerns among neurosurgeons due to the vagueness of clinical presentations. Specifically, frontal lesions do not necessarily present with common lateralising signs in the early stages, which can obscure problems during neurological examinations and lead to abrupt deterioration resulting from craniocaudal herniation in later stages [20]. Moreover, compared to patients with unilateral hematomas, those with bifrontal hematomas face a significantly higher risk of deterioration and poor outcome [20,21]. In the current study, all seven of the patients (three unifrontal and four bifrontal) presented marked neurological deficits and were in critical condition due to an increase in intracranial pressure (ICP). Following DC and the removal of hematomas, five of the patients recovered to GCS score 15 and obtained GOS scores of 4 or 5. Moreover, serious concerns have been raised about unfavourable outcomes that often occur in patients with a skull bone defect following DC [22]. These negative effects include external cerebral herniation, subdural hygroma, posttraumatic hydrocephalus, and trephined syndrome [23]. The authors view DC as a double-edged sword. It is an extreme method capable of saving lives in cases of severe brain injury; however, it can cause sequelae in surviving patients. Nonetheless, the potential benefits DC offers TBI patients should not be discounted. It was previously believed that a multistage approach would be preferable in cases of bilateral cranioplasty. This belief was based on the assumption that the risk of infection would increase if skull injuries were repaired in a single stage [15]. However, recent clinical reports have challenged these assumptions in cases where titanium mesh is used. For example, Marbacher et al. reported on five patients with depressed skull fractures who underwent
primary, single-stage reconstruction with titanium mesh. No infection occurred in any of these patients, which prompted the authors to suggest that the single-stage titanium mesh reconstruction technique is superior to the conventional staged approach [24]. Moreover, our previously published data provided evidence that bilateral titanium cranioplasty following F-T-P DC could be completed in a single operation [15]. Furthermore, results from the current work show that the use of a one-piece implant in a single operation is also applicable to patients with bifrontal skull defects. In cases of large skull defects, titanium mesh reconstruction offers a favourable alternative to PMMA cranioplasty by eliminating the time-consuming task of contour moulding. Moreover, according to Di Silvestre et al. [25], less aggressive surgical procedures should be used when treating the elderly in order to limit blood loss, reduce operating time, and minimise complications. Based on the abovementioned concerns, we recommend the use of titanium mesh reconstruction for elderly patients. This approach offers single-stage repair in bilateral skull defects and employs CAD/CAM-fabricated products, which can reduce intraoperative contour moulding times and limit the likelihood of perioperative complications. We suggest that primary, singlestage repair techniques are superior to conventional methods, particularly among elderly patients and those requiring bilateral reconstruction. Previously, we applied the CIS method to evaluate the aesthetic outcomes of cranioplasty in the F-T-P region using implants made of titanium [15] and reformed PMMA [1]. It is particularly worth mentioning that results of CIS (e.g., aesthetic outcomes in frontal cranioplasty) are not easily quantified. Thus, this study only assessed qualitative aesthetic outcomes. Qualitative analysis prompts the need for further analytical quantification in frontal reconstruction. In conclusion, the advantages of using 3-D CAD titanium mesh implants for frontal cranial reconstruction include representative forehead contours, excellent cosmesis, fully functional trigeminal and facial nerves, complete healing, and few complications. Our results demonstrate the safety, practicality, and stability of this surgical technique, and also show that titanium mesh is a favourable alternative to other graft materials in the repair of frontal skull defects. Conflict of interest The authors confirm that they have no conflict of interest regarding this paper. References [1] Kung WM, Lin MS. A simplified technique for polymethyl methacrylate cranioplasty: combined cotton stacking and finger fracture method. Brain Inj 2012;26(13–14):1737–42. [2] Schaller B, Graf R, Sanada Y, Rosner G, Wienhard K, Heiss WD. Hemodynamic and metabolic effects of decompressive hemicraniectomy in normal brain: an experimental PET-study in cats. Brain Res 2003;982(August (1)):31–7. [3] Segal DH, Oppenheim JS, Murovic JA. Neurological recovery after cranioplasty. Neurosurgery 1994;34(April (4)):729–31. [4] Scholz M, Wehmoller M, Lehmbrock J, Schmieder K, Engelhardt M, Harders A, et al. Reconstruction of the temporal contour for traumatic tissue loss using a CAD/CAM-prefabricated titanium implant-case report. J Craniomaxillofac Surg 2007;35(December (8)):388–92. [5] Joseph V, Reilly P. Syndrome of the trephined. J Neurosurg 2009;111(October (4)):650–2. [6] Lakhani RS, Shibuya TY, Mathog RH, Marks SC, Burgio DL, Yoo GH. Titanium mesh repair of the severely comminuted frontal sinus fracture. Arch Otolaryngol Head Neck Surg 2001;127(June (6)):665–9. [7] Matic DB, Manson PN. Biomechanical analysis of hydroxyapatite cement cranioplasty. J Craniofac Surg 2004;15(May (3)):415–22. [8] Kaiser A, Illi OE, Sailer HF, Stauffer UG. Cranioplasties for congenital and acquired skull defects in children – comparison of new concepts with conventional methods. Eur J Pediatr Surg 1993;3(August (4)):236–40.
S.-T. Chen et al. / Injury, Int. J. Care Injured 46 (2015) 80–85 [9] Staffa G, Nataloni A, Compagnone C, Servadei F. Custom made cranioplasty prostheses in porous hydroxy-apatite using 3D design techniques: 7 years experience in 25 patients. Acta Neurochir (Wien) 2007;149(February (2)):161–70. [10] Grant GA, Jolley M, Ellenbogen RG, Roberts TS, Gruss JR, Loeser JD. Failure of autologous bone-assisted cranioplasty following decompressive craniectomy in children and adolescents. J Neurosurg 2004;100(February (2 Suppl. Pediatrics)):163–8. [11] Cabraja M, Klein M, Lehmann TN. Long-term results following titanium cranioplasty of large skull defects. Neurosurg Focus 2009;26(June (6)):E10. [12] Malis LI. Titanium mesh and acrylic cranioplasty. Neurosurgery 1989;25(September (3)): 351–5. [13] Janecka IP. New reconstructive technologies in skull base surgery: role of titanium mesh and porous polyethylene. Arch Otolaryngol Head Neck Surg 2000;126(March (3)):396–401. [14] Galantucci LM, Percoco G, Angelelli G, Lopez C, Introna F, Liuzzi C, et al. Reverse engineering techniques applied to a human skull, for CAD 3D reconstruction and physical replication by rapid prototyping. J Med Eng Technol 2006;30(March (2)):102–11. [15] Kung WM, Lin FH, Hsiao SH, Chiu WT, Chyau CC, Lu SH, et al. New reconstructive technologies after decompressive craniectomy in traumatic brain injury: the role of three-dimensional titanium mesh. J Neurotrauma 2012;29(July (11)):2030–7. [16] Huang X, Wen L. Technical considerations in decompressive craniectomy in the treatment of traumatic brain injury. Int J Med Sci 2010;7(6):385–90.
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[17] Bratzler DW, Dellinger EP, Olsen KM, Perl TM, Auwaerter PG, Bolon MK, et al. Clinical practice guidelines for antimicrobial prophylaxis in surgery. Am J Health Syst Pharm 2013;70(February (3)):195–283. [18] Ju DT, Lin JW, Lin MS, Lee LM, Tseng HM, Wei CP, et al. Hypofractionated CyberKnife stereotactic radiosurgery for acoustic neuromas with and without association to neurofibromatosis Type 2. Acta Neurochir Suppl (Wien) 2008;101:169–73. [19] House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93(April (2)):146–7. [20] Hung KS, Liang CL, Wang CH, Chang HW, Park N, Juo SH. Outcome after traumatic frontal intracerebral haemorrhage: a comparison of unilateral and bilateral haematomas. J Clin Neurosci 2004;11(November (8)):849–53. [21] Statham PF, Johnston RA, Macpherson P. Delayed deterioration in patients with traumatic frontal contusions. J Neurol Neurosurg Psychiatry 1989;52(March (3)): 351–4. [22] Cooper DJ, Rosenfeld JV, Murray L, Arabi YM, Davies AR, D’Urso P, et al. Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med 2011;364(April (16)):1493–502. [23] Margules A, Jallo J. Complications of decompressive craniectomy. JHN J. 2010;5(16):9–12. [24] Marbacher S, Andres RH, Fathi AR, Fandino J. Primary reconstruction of open depressed skull fractures with titanium mesh. J Craniofac Surg 2008;19(March (2)):490–5. [25] Di SM, Lolli F, Greggi T, Vommaro F, Baioni A. Adult’s degenerative scoliosis: midterm results of dynamic stabilization without fusion in elderly patients – is it effective? Adv Orthop 2013;2013:365059.
Contents lists available at ScienceDirect
Injury journal homepage: www.elsevier.com/locate/injury
3-D titanium mesh reconstruction of defective skull after frontal craniectomy in traumatic brain injury Shuo-Tsung Chen a, Cheng-Jen Chang b, Wei-Chin Su d, Lin-Wan Chang d, I-Hsuan Chu d, Muh-Shi Lin c,d,e,* a
Department of Mathematics, Tunghai University, Taichung, Taiwan Department of Plastic Surgery, Chang Gung Memorial Hospital, Chang Gung University, Taoyuan, Taiwan Department of Surgery, Faculty of Medicine, School of Medicine, National Yang-Ming University, Taipei, Taiwan d Department of Neurosurgery, Taipei City Hospital, Zhong Xiao Branch, Taipei, Taiwan e Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan b c
A R T I C L E I N F O
A B S T R A C T
Article history: Accepted 25 September 2014
Introduction: Decompressive craniectomy (DC) is a treatment strategy used to reduce intracranial pressure in patients with traumatic brain injuries. However, this procedure has a number of shortcomings, such as excessive sinking of the skin flap, which can lead to cerebral compromise and negatively affect the appearance of the patient. The reconstruction of skull defects has been proposed as a means to overcome these disadvantages. Few previous studies have reported the reconstruction of frontal skull defects using titanium mesh. The aim of this study was to provide a comprehensive review of aesthetic and surgical outcomes associated with this procedure and to list the complications encountered during the repair of frontal skull defects using three-dimensional (3-D) titanium mesh. Methods: A retrospective review was conducted using records from seven adult patients (32–60 years of age) who received titanium mesh implants at a university hospital in Taiwan between January 2011 and June 2012. Aesthetic outcomes, the function of cranial nerves V and VII, and complications (hardware extrusions, meningitis, osteomyelitis, brain abscess, and pneumocephalus) were evaluated. Results: An algorithm capable of accounting for bifrontal skull defects and median bone ridges was developed to improve computer-assisted design/manufacturing (CAD/CAM) of one-piece 3-D titanium mesh implants, thereby making it possible to repair bifrontal skull defects in a single operation. Following this procedure, aesthetic and functional outcomes were excellent and the implants in all patients appeared stable. However, extended healing times in two of the patients resulted in subclinical infections, which were resolved by administering antibiotics over a period of 2 weeks. No patients suffered trigeminal or facial dysfunction. Conclusions: Our findings support the use of 3-D titanium mesh in frontal skull reconstruction. Few complications were encountered, the contours of the forehead were faithfully rendered, and the cosmetic appearance of patients was excellent. For patients with bifrontal skull defects, the use of onepiece implants in a single operation provides numerous advantages over conventional staged surgeries. This application helps to reduce operating time, which is particularly beneficial for elderly patients and those requiring bifrontal cranioplasties. ß 2014 Elsevier Ltd. All rights reserved.
Keywords: Frontal intracranial haemorrhage Head injury Decompressive craniectomy Three-dimensional titanium mesh Reconstruction Cosmesis Quality of life
Introduction Following decompressive craniectomy (DC), some patients with skull bone defects develop a sunken or flattened skin flap
* Corresponding author at: Department of Neurosurgery, Number 87, Tongde Road, Nangang District, Taipei City 115, Taiwan. Tel.: +886 2 27861288; fax: +886 2 27888492. E-mail address: [email protected] (M.-S. Lin). http://dx.doi.org/10.1016/j.injury.2014.09.019 0020–1383/ß 2014 Elsevier Ltd. All rights reserved.
(i.e., trephined syndrome). This complication is particularly prevalent among the elderly [1]. Excessive sinking of the skin flap can result in local compression, which can in turn disturb brain autoregulation and compromise cerebral haemodynamic status [2,3]. However, this dire situation can be avoided by reconstructing skull defects. Cranioplasty plays a critical role in protecting intracranial content from exposure and compression (from atmospheric pressure) and also helps to correct disfigurement [4]. Following cranioplasty, many patients with ‘‘syndrome of the
S.-T. Chen et al. / Injury, Int. J. Care Injured 46 (2015) 80–85
trephined’’ present a deterioration in neurological status [5]. It appears that clinical improvements following cranioplasty may be due to the restoration of normal brain anatomy, cerebral reexpansion, and recovery of normal scalp flap curvature [5]. Various techniques and materials have been used in the repair of skull defects following DC, such as autogenous bone grafts and xenogenetic or alloplastic implants [1,6–10]. Considerable advances have been made in computer-assisted design/manufacturing (CAD/ CAM) to improve the quality of implants. A number of studies have reported the effectiveness of three-dimensional (3-D) CAD/CAM implants in craniofacial skeletal reconstruction with regard to improved cosmesis and fewer complications, compared to conventional autogenous or alloplastic bone, particularly in patients with large skull defects [4,11–13]. Most previous studies on the use of CAD/CAM-fabricated implants have focused on the repair of skull defects following fronto-temporo-parietal (F-T-P) DC (standard trauma craniectomy) [4,11,14]. For example, we previously presented a quantitative analysis of craniofacial symmetry based on the cranial index of symmetry (CIS) following craniofacial skeletal reconstructions using polymethyl methacrylate (PMMA) [1] and titanium cranioplasty [15]. However, little is currently known about the use of CAD/CAM-fabricated implants in the repair of skull defects following frontal DC. This study reviewed the results of seven patients who underwent frontal craniectomy (three unilateral and four bifrontal) using 3-D titanium mesh implants in our institution. Specifically, a one-piece titanium mesh was used to cover bifrontal skull defects and the frontal median bone ridge as an alternative to conventional methods applied bilaterally using multiple implants. Materials and methods Patients Between January 2011 and June 2012, seven consecutive patients aged 32–60 years with severe head injuries and frontal intracranial hematomas were treated in our institution. All patients presented pronounced neurological deficits and
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underwent cranial decompressive surgery. Operative methods included a bicoronal scalp flap and frontal DC to remove a haematoma on one side (n = 3) or both sides (n = 4). In patients with unifrontal DCs, a bicoronal skin flap was implemented and frontal bones on the lesioned side were removed. In cases of bifrontal DC, we bilaterally removed the frontal bones and preserved a frontal median bone ridge (single arrow in Fig. 3E) over the superior sagittal sinus to prevent bleeding [16]. All seven patients appeared physically and neurologically stable at an average of 1.8 months postcraniectomy, whereupon they underwent cranioplasty using seven 3-D titanium mesh implants. Three patients with a unifrontal skull defect underwent unilateral cranioplasty on the lesioned side. Four patients with bifrontal skull defects underwent a bilateral cranioplasty using a one-piece 3-D titanium mesh that provided bilateral coverage over both sides (Fig. 1). 3-D titanium mesh design Brain computed tomographic (CT) scans and CAD/CAM of 3-D titanium mesh for F-T-P skull defects were as described in our previous study [15]. Briefly, each patient received a CT scan on the area of the brain representing a slice (1.25 mm thick) from the base of the skull to convexity (including the region of the skull defect). These high-resolution CT images were then transferred to Medtronic (Golenta, CA, USA) for use in the 3-D CAD design of skull segments. Image-editing software was used to extract digital information from the CT scans, which in turn guided the reconstruction of the contours of area(s) containing skull defects. Contour reconstruction had to account for bilateral frontal skull defects and frontal median bone ridges in patients who had undergone bifrontal DCs (arrow in Fig. 2E and F). The symmetry of the reconstructed contours and their relationship with existing skull bone were simultaneously investigated from axial, coronal, and sagittal views (Fig. 2A, B, E and F). We observed the 3-D CAD reconstruction of artificial flaps and cranial segments using an image-editing software in order to evaluate implants in terms of external appearance and symmetry (Fig. 2C, D, G and H).
Fig. 1. Representative photographs of TBI patients before and after titanium mesh reconstruction. (A–D) Case 1, unifrontal DC; (E–H) Case 2, bifrontal DC. (A) Preoperative CT scan revealing a fracture in which bone fragments separated intraparenchymally at the left frontal lobe. (E) Preoperative CT scan revealing acute bifrontal intracerebral haemorrhage with significant mass effects. (B and F) Depression appearing on the patient’s forehead following DC. The appearance of a patient’s forehead after cranioplasty using 3-D CAD/CAM-fabricated titanium mesh at 30 days (C, G) and 2 years (D, H) postoperatively.
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Fig. 2. Editing 2-D images of brain CT scans and 3-D CAD reconstruction of frontal skull defects. (A–D) Case 1, unilateral skull defect; (E–H) Case 2, bifrontal skull defect. Reconstructed contour of skull defect was generated and simultaneously observed via axial (A, E), and coronal (B, F) views. Image of 3-D reconstruction shows frontal skull defect (C, G) and reconstructed artificial flap (blue colour) (D, H). External appearance and symmetry of 3-D CAD reconstructions can be checked simultaneously. (For interpretation of the references to colour in this figure legend, the reader is referred to the web version of the article.)
CAD data were then transferred to a CAM system, in which the final implant (Fig. 3B, F) was stamp-moulded. The 3-D titanium mesh was evaluated and formally approved by the manufacturer. In addition, physicians verified labelled margins, skull defects, and flap contours (triple arrow in Fig. 3F) prior to performing cranioplasty. The titanium mesh used in all of the patients had a standard uniform thickness of 0.6 mm. For patients with bifrontal DCs, this was sufficiently thin to ensure that the titanium mesh overlapped the frontal median bone ridge with no visible deformities. Operating procedures for 3-D titanium mesh cranioplasty to treat frontal skull defects A single dose of 1 g cefazolin was administered intravenously within 60 min prior to cranioplasty [17]. The frontobasal region was exposed through a previous incision, and the scalp was dissected and reflected to expose a region extending beyond the skull defect. The subgaleal space of the scalp was dissected to release any tension that might occur during wound closure. The tissue above the periosteum (epidural space) was also reflected. Approaching the epidural space, leakage of cerebrospinal fluid (CSF) was avoided by taking care to avoid dural tearing. An intact arachnoid membrane (double arrow in Fig. 3E) was also necessary to prevent CSF leakage. The titanium mesh was designed to be anchored epidurally in order to cover all skull defects. Thus, the periosteum and soft tissue around the margins of the skull defects had to be completely removed (arrow in Fig. 3A) in order to enhance implant reduction. Dural tenting sutures with central and circumferential placement were used to eliminate any dead space between the dura and implant (arrow in Fig. 3B and double arrow in Fig. 3F). Following complete hemostasis, the titanium mesh was set in place over the skull defects. (To ensure accurate positioning, the margins of the skull defects had been previously marked on the titanium mesh
(triple arrow in Fig. 3F).) The titanium mesh was anchored in place using 4- or 5-mm screws. Upon stabilising the mesh, the periosteum and soft tissues were tacked in place using suspensory 3/0 Vicryl sutures with the aim of restoring the original anatomy (single arrow in Fig. 3B and F). One or two Jackson–Pratt drains were then emplaced near the frontal base above the titanium mesh to facilitate blood drainage. The galeal layer was closed using multiple interrupted 2/0 Vicryl sutures and the skin was closed using interrupted mattress nylon sutures. Careful alignment of the skin edges was essential to achieve aesthetically pleasing and functional results. Finally, a sterile head dressing was placed over the entire area and held in place until the sutures were removed at 10 days postoperatively. The Jackson–Pratt drains were left in place until drainage was negligible, for a minimum of 2 days after surgery. Outcome measures Cosmesis Aesthetic results were based on postoperative reconstruction radiographs and feedback from the patient and/or the patient’s family. For this feedback, patients or family members evaluated gross external appearance pre- and postcranioplasty using a fourpoint scale, in which 0 indicated no deformity, 1 indicated mild deformity, 2 indicated moderate deformity, and 3 indicated severe deformity [6]. Evaluation of pain Pain was evaluated using a 10-point visual analogue scale (VAS). Patients were required to mark a point on the VAS to indicate the intensity of pain they were experiencing, with 0 indicating no pain and 10 indicating the worst possible pain. Evaluation of cranial nerve Trigeminal nerve function (cranial nerve V) was graded using a three-point semiquantitative scale [6,18], and facial nerve function
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Fig. 3. Representative intraoperative and postoperative computed tomography (CT) images of patients. (A–D) Case 1, unifrontal skull defect; (E–H) Case 2, bifrontal skull defect. Intraoperative exposure of skull defects unilaterally (A) and bilaterally (E) with the preservation of a frontal median bone ridge (single arrow in 3 E). (B and F) CAD/CAM titanium implants for the reconstruction of skull defects. A one-piece titanium mesh was used for the reconstruction of bifrontal skull defects (F). Postoperative axial (C and G) and coronal (D and H) CT scan after reconstruction with titanium mesh showing good symmetry.
(cranial nerve VII) was graded using the six-point House– Brackmann grading system [19]. Complications Data related to complications, such as infection and persistent headache, as well as intracranial complications such as meningitis, brain abscesses, CSF leaks, mucopyocele, and hardware extrusions, were recorded. Complications that occurred within 30 days of cranioplasty were considered postoperative complications. Statistical analysis Descriptive statistics was used to describe the demographic characteristics of the patients. Continuous data are shown as the mean standard deviation (SD), while categorical data are represented by number (n) and percentage (%). Statistical analysis was performed using SPSS 15.0 software (SPSS Inc., Chicago, IL, USA). Results Patient characteristics Between January 2011 and June 2012, seven consecutive patients with major head trauma underwent craniofacial skeletal reconstruction. This group included five males and two females with a mean age of 47.43 10.86 years (range 32–60 years). The cause of traumatic brain injury (TBI) included falls (n = 3), motor vehicle accidents (n = 3), and impacts (n = 1). The average time between cranioplasty and craniectomy was 1.8 months. Three patients required unifrontal cranioplasty and four required bifrontal cranioplasty. The four patients who underwent bifrontal cranioplasty did so during a single operation using a one-piece 3-D titanium mesh, which completely covered the bifrontal skull defects. The mean operating time for skin to skin was 116.1 22.84 min (range of 93– 161 min); the average blood loss was 257.3 mL (range of 50–470 mL); and the mean duration of follow-up was 28.57 4.791 months (range of 19–33 months).
Cosmesis Among the seven patients, five recovered to Glasgow Coma Scale (GCS) score 15 and received Glasgow Outcome Scale (GOS) scores of 4 or 5 (before and after cranioplasties). These five fully conscious patients and the families of the two other patients completed the evaluation of cosmetic outcomes. Grades awarded by patients and families were based on the gross external appearance of the skull before and after cranioplasty. All seven patients received a grade of 0 (no deformity) for the forehead contour after surgery. In addition, we evaluated aesthetic outcomes using postoperative reconstruction radiographs. All postoperative CT images showed good reconstruction of skull defects (Fig. 3D, E, G and H). Extent of pain The five fully conscious patients were also candidates for VAS evaluation. Two of the five patients complained of postoperative pain in the area of the procedure, which necessitated the use of controlled analgesics (patient-controlled analgesia, PCA). The other patients controlled postoperative scalp pain by taking oral analgesics three times per day for 3 days. All five patients had a VAS score of 0; that is, they felt no pain by postoperative day 5 (POD). At follow-up clinic visits, the five patients were asked whether they took analgesics for pain specific to the procedure before obtaining a final VAS score. The final VAS score at a mean follow-up of almost 29 months was 0. Cranial nerve function Compared with preoperative facial sensation, the five fully conscious patients presented no change in the function of cranial nerve V. Furthermore, all seven of the patients had normal symmetrical facial nerve function in all areas (Grade 1). Complications The healing of incisions in two patients with type 1 diabetes was delayed, resulting in subsequent subclinical infection, which
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was resolved following 2 weeks of antibiotic treatment. The two patients received nonsurgical interventions (wound debridement), which resulted in complete healing, showing no sign of deterioration throughout the follow-up period of nearly 29 months. To date, no instances of implant extrusion or intracranial complications, including persistent headaches, meningitis, osteomyelitis, brain abscesses, CSF leaks, pneumocephalus, or mucopyocele, have been reported among any of the seven patients in long-term follow-up. Discussion In this study, we conducted a retrospective review of seven patients with head trauma who underwent DC and the reconstruction of defective frontal skulls using 3-D CAD/CAM-derived titanium mesh implants. Following implantation, the aesthetic, radiological, and functional outcomes of all patients were good. Postoperative complications, such as wound pain and infection, were similar to those previously reported in the F-T-P region [15], and no other serious postoperative complications were encountered. At the present mean follow-up of nearly 29 months (range 19–33 months), no headaches, wound infections, or intracranial/ hardware complications have been noted. These results demonstrate the safety, stability, and practicality of reconstruction techniques for the repair of frontal skull defects. Specifically, the current study evaluated the use of 3-D titanium mesh in bifrontal cranioplasties. The highlights of this study are as follows: (1) The proposed CAD/CAM model includes algorithms and techniques to provide seamless coverage of bifrontal skull defects and the median ridge by reconstructing the original contours of the skull. (2) The extreme thinness of the implant (6 mm) renders it essentially indistinguishable from the original bone. (3) The use of one-piece 3-D titanium mesh devices makes it possible to perform cranioplasties on both sides of the skull in a single operation. Although the sample size was small in this study, we have nonetheless demonstrated the clinical efficacy of the procedure. Frontal intracranial hematomas in TBI patients have raised concerns among neurosurgeons due to the vagueness of clinical presentations. Specifically, frontal lesions do not necessarily present with common lateralising signs in the early stages, which can obscure problems during neurological examinations and lead to abrupt deterioration resulting from craniocaudal herniation in later stages [20]. Moreover, compared to patients with unilateral hematomas, those with bifrontal hematomas face a significantly higher risk of deterioration and poor outcome [20,21]. In the current study, all seven of the patients (three unifrontal and four bifrontal) presented marked neurological deficits and were in critical condition due to an increase in intracranial pressure (ICP). Following DC and the removal of hematomas, five of the patients recovered to GCS score 15 and obtained GOS scores of 4 or 5. Moreover, serious concerns have been raised about unfavourable outcomes that often occur in patients with a skull bone defect following DC [22]. These negative effects include external cerebral herniation, subdural hygroma, posttraumatic hydrocephalus, and trephined syndrome [23]. The authors view DC as a double-edged sword. It is an extreme method capable of saving lives in cases of severe brain injury; however, it can cause sequelae in surviving patients. Nonetheless, the potential benefits DC offers TBI patients should not be discounted. It was previously believed that a multistage approach would be preferable in cases of bilateral cranioplasty. This belief was based on the assumption that the risk of infection would increase if skull injuries were repaired in a single stage [15]. However, recent clinical reports have challenged these assumptions in cases where titanium mesh is used. For example, Marbacher et al. reported on five patients with depressed skull fractures who underwent
primary, single-stage reconstruction with titanium mesh. No infection occurred in any of these patients, which prompted the authors to suggest that the single-stage titanium mesh reconstruction technique is superior to the conventional staged approach [24]. Moreover, our previously published data provided evidence that bilateral titanium cranioplasty following F-T-P DC could be completed in a single operation [15]. Furthermore, results from the current work show that the use of a one-piece implant in a single operation is also applicable to patients with bifrontal skull defects. In cases of large skull defects, titanium mesh reconstruction offers a favourable alternative to PMMA cranioplasty by eliminating the time-consuming task of contour moulding. Moreover, according to Di Silvestre et al. [25], less aggressive surgical procedures should be used when treating the elderly in order to limit blood loss, reduce operating time, and minimise complications. Based on the abovementioned concerns, we recommend the use of titanium mesh reconstruction for elderly patients. This approach offers single-stage repair in bilateral skull defects and employs CAD/CAM-fabricated products, which can reduce intraoperative contour moulding times and limit the likelihood of perioperative complications. We suggest that primary, singlestage repair techniques are superior to conventional methods, particularly among elderly patients and those requiring bilateral reconstruction. Previously, we applied the CIS method to evaluate the aesthetic outcomes of cranioplasty in the F-T-P region using implants made of titanium [15] and reformed PMMA [1]. It is particularly worth mentioning that results of CIS (e.g., aesthetic outcomes in frontal cranioplasty) are not easily quantified. Thus, this study only assessed qualitative aesthetic outcomes. Qualitative analysis prompts the need for further analytical quantification in frontal reconstruction. In conclusion, the advantages of using 3-D CAD titanium mesh implants for frontal cranial reconstruction include representative forehead contours, excellent cosmesis, fully functional trigeminal and facial nerves, complete healing, and few complications. Our results demonstrate the safety, practicality, and stability of this surgical technique, and also show that titanium mesh is a favourable alternative to other graft materials in the repair of frontal skull defects. Conflict of interest The authors confirm that they have no conflict of interest regarding this paper. References [1] Kung WM, Lin MS. A simplified technique for polymethyl methacrylate cranioplasty: combined cotton stacking and finger fracture method. Brain Inj 2012;26(13–14):1737–42. [2] Schaller B, Graf R, Sanada Y, Rosner G, Wienhard K, Heiss WD. Hemodynamic and metabolic effects of decompressive hemicraniectomy in normal brain: an experimental PET-study in cats. Brain Res 2003;982(August (1)):31–7. [3] Segal DH, Oppenheim JS, Murovic JA. Neurological recovery after cranioplasty. Neurosurgery 1994;34(April (4)):729–31. [4] Scholz M, Wehmoller M, Lehmbrock J, Schmieder K, Engelhardt M, Harders A, et al. Reconstruction of the temporal contour for traumatic tissue loss using a CAD/CAM-prefabricated titanium implant-case report. J Craniomaxillofac Surg 2007;35(December (8)):388–92. [5] Joseph V, Reilly P. Syndrome of the trephined. J Neurosurg 2009;111(October (4)):650–2. [6] Lakhani RS, Shibuya TY, Mathog RH, Marks SC, Burgio DL, Yoo GH. Titanium mesh repair of the severely comminuted frontal sinus fracture. Arch Otolaryngol Head Neck Surg 2001;127(June (6)):665–9. [7] Matic DB, Manson PN. Biomechanical analysis of hydroxyapatite cement cranioplasty. J Craniofac Surg 2004;15(May (3)):415–22. [8] Kaiser A, Illi OE, Sailer HF, Stauffer UG. Cranioplasties for congenital and acquired skull defects in children – comparison of new concepts with conventional methods. Eur J Pediatr Surg 1993;3(August (4)):236–40.
S.-T. Chen et al. / Injury, Int. J. Care Injured 46 (2015) 80–85 [9] Staffa G, Nataloni A, Compagnone C, Servadei F. Custom made cranioplasty prostheses in porous hydroxy-apatite using 3D design techniques: 7 years experience in 25 patients. Acta Neurochir (Wien) 2007;149(February (2)):161–70. [10] Grant GA, Jolley M, Ellenbogen RG, Roberts TS, Gruss JR, Loeser JD. Failure of autologous bone-assisted cranioplasty following decompressive craniectomy in children and adolescents. J Neurosurg 2004;100(February (2 Suppl. Pediatrics)):163–8. [11] Cabraja M, Klein M, Lehmann TN. Long-term results following titanium cranioplasty of large skull defects. Neurosurg Focus 2009;26(June (6)):E10. [12] Malis LI. Titanium mesh and acrylic cranioplasty. Neurosurgery 1989;25(September (3)): 351–5. [13] Janecka IP. New reconstructive technologies in skull base surgery: role of titanium mesh and porous polyethylene. Arch Otolaryngol Head Neck Surg 2000;126(March (3)):396–401. [14] Galantucci LM, Percoco G, Angelelli G, Lopez C, Introna F, Liuzzi C, et al. Reverse engineering techniques applied to a human skull, for CAD 3D reconstruction and physical replication by rapid prototyping. J Med Eng Technol 2006;30(March (2)):102–11. [15] Kung WM, Lin FH, Hsiao SH, Chiu WT, Chyau CC, Lu SH, et al. New reconstructive technologies after decompressive craniectomy in traumatic brain injury: the role of three-dimensional titanium mesh. J Neurotrauma 2012;29(July (11)):2030–7. [16] Huang X, Wen L. Technical considerations in decompressive craniectomy in the treatment of traumatic brain injury. Int J Med Sci 2010;7(6):385–90.
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[17] Bratzler DW, Dellinger EP, Olsen KM, Perl TM, Auwaerter PG, Bolon MK, et al. Clinical practice guidelines for antimicrobial prophylaxis in surgery. Am J Health Syst Pharm 2013;70(February (3)):195–283. [18] Ju DT, Lin JW, Lin MS, Lee LM, Tseng HM, Wei CP, et al. Hypofractionated CyberKnife stereotactic radiosurgery for acoustic neuromas with and without association to neurofibromatosis Type 2. Acta Neurochir Suppl (Wien) 2008;101:169–73. [19] House JW, Brackmann DE. Facial nerve grading system. Otolaryngol Head Neck Surg 1985;93(April (2)):146–7. [20] Hung KS, Liang CL, Wang CH, Chang HW, Park N, Juo SH. Outcome after traumatic frontal intracerebral haemorrhage: a comparison of unilateral and bilateral haematomas. J Clin Neurosci 2004;11(November (8)):849–53. [21] Statham PF, Johnston RA, Macpherson P. Delayed deterioration in patients with traumatic frontal contusions. J Neurol Neurosurg Psychiatry 1989;52(March (3)): 351–4. [22] Cooper DJ, Rosenfeld JV, Murray L, Arabi YM, Davies AR, D’Urso P, et al. Decompressive craniectomy in diffuse traumatic brain injury. N Engl J Med 2011;364(April (16)):1493–502. [23] Margules A, Jallo J. Complications of decompressive craniectomy. JHN J. 2010;5(16):9–12. [24] Marbacher S, Andres RH, Fathi AR, Fandino J. Primary reconstruction of open depressed skull fractures with titanium mesh. J Craniofac Surg 2008;19(March (2)):490–5. [25] Di SM, Lolli F, Greggi T, Vommaro F, Baioni A. Adult’s degenerative scoliosis: midterm results of dynamic stabilization without fusion in elderly patients – is it effective? Adv Orthop 2013;2013:365059.
