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TABLE 3. Types of Diplopia According to Symptomatic Orbital Wall Fractures in the Study Population All Directions Floor 62 (79.2%) Medial wall 9 (11.7%) Lateral wall 1 (1.3%) Floor + 6 (7.8%) medial wall Floor + 0 lateral wall Total 78
Elevation and Depression 56 (86.1%) 2 (3.1%) 0 7 (10.8%)
Elevation
Depression Horizontal
53* (93%) 14 (87.6%) 4 (36.4%) 1 (1.7%) 1 (6.2%) 7† (63.6%) 0 0 0 3 (5.3%) 1 (6.2%) 0
0
0
0
0
65
57
16
11
*P G 0.05. †P G 0.000005.
Brief Clinical Studies
Computer-Designed Polyetheretherketone Implants Versus Titanium Mesh (TAcrylic Cement) in Alloplastic Cranioplasty: A Retrospective Single-Surgeon, Single-Center Study Zhi Yang Ng, MBChB,* Wei Jie Jensen Ang, BMedSci(Hons),Þ Irfan Nawaz, MBBS, FRCSþ
between horizontal diplopia and medial wall fractures (P G 0.000005) (Table 3).
CONCLUSIONS Our findings suggest that, in patients under evaluation for orbital trauma, the observation of diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively. As the clinical investigation still remains an important indicator for open surgery, together with the radiologic investigation, posttraumatic orbital clinical signs should be precisely assessed to help in the diagnosis and surgical planning.
REFERENCES 1. Bagheri SC, Dierks EJ, Kademani D, et al. Application of a facial injury severity scale in craniomaxillofacial trauma. J Oral Maxillofac Surg 2006;64:408Y414 2. Folkestad L, Lindgren G, Moller C, et al. Diplopia in orbital fractures: a simple method to evaluate eye motility. Acta Otolaryngol 2007;127:156Y166 3. Gosse EM, Ferguson AW, Lymburn EG, et al. Blow-out fractures: patterns of ocular motility and effect of surgical repair. Br J Oral Maxillofac Surg 2010;48:40Y43 4. Jank S, Schuchter B, Emshoff R, et al. Clinical signs of orbital wall fractures as a function of anatomic location. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;96:149Y153 5. Lee SH, Lew H, Yun YS. Ocular motility disturbances in orbital wall fracture patients. Yonsei Med J 2005;46:359Y367 6. Park MS, Kim YJ, Kim H, et al. Prevalence of diplopia and extraocular movement limitation according to the location of isolated pure blowout fractures. Arch Plast Surg 2012;39:204Y208 7. Roccia F, Boffano P, Guglielmi V, et al. Role of the maxillofacial surgeon in the management of severe ocular injuries after maxillofacial fractures. J Emerg Trauma Shock 2011;4:188Y193 8. Vriens JP, Moos KF. Morbidity of the infraorbital nerve following orbitozygomatic complex fractures. J Craniomaxillofac Surg 1995;23:363Y368 9. Boffano P, Roccia F, Gallesio C, et al. Bicycle-related maxillofacial injuries: a double-center study. Oral Surg Oral Med Oral Pathol Oral Radiol 2013;116:275Y280 10. Roccia F, Boffano P, Bianchi FA, et al. Maxillofacial injuries due to work-related accidents in the North West of Italy. Oral Maxillofac Surg 2013;17:181Y186
Background: Polyetheretherketone (PEEK) has emerged as one of the most promising alloplastic materials for calvarial reconstruction because of a number of desirable qualities including resistance to heat and ionizing radiation, biocompatibility, biomechanically similar to native bone, and being nonferromagnetic for postoperative monitoring. We aimed to evaluate and compare the outcomes of alloplastic cranioplasty performed with PEEK, titanium mesh only (Ti-only), and titanium mesh with acrylic cement (Ti-AC); titanium mesh has previously recorded many successes with low complication rates. Methods: A retrospective, single-surgeon, single-center study for alloplastic cranioplasties was performed between January 2008 and December 2012. Titanium meshes were fashioned intraoperatively, whereas PEEK implants were prefabricated from high-resolution computed tomography scans. Patients were routinely followed up in outpatient settings. Results: Twenty-four patients (75% male) underwent delayed cranioplasty following initial craniectomy. Four Ti-only and 3 Ti-AC patients had postoperative complications including wound breakdown and implant exposure. These assumed a bimodal distribution with time postoperatively and culminated in implant removal in 6 patients, of which 4 required further plastic flap coverage. Subgroup analysis showed no significant differences in predictive factors apart from cranioplasty material with means as follows: age = 42 years, interval to surgery = 10 months, defect size = 12 9 cm, operation duration = 181 minutes, hospital stay = 13 days, follow-up = 11 months. Conclusions: Early results suggest that PEEK may be superior to Ti-only or Ti-AC as an alloplastic cranioplasty choice. Further research should include randomized trials between computer-aided,
From the *Department of Plastic Reconstructive and Aesthetic Surgery, KK Women’s and Children’s Hospital, Singapore; †College of Medicine and Veterinary Medicine, University of Edinburgh, Scotland, United Kingdom; and ‡Division of Neurosurgery, Changi General Hospital, Singapore. Received September 23, 2013. Accepted for publication December 2, 2013. Address correspondence and reprint requests to Zhi Yang Ng, MBChB, Department of Plastic Reconstructive and Aesthetic Surgery, KK Women’s and Children’s Hospital, 100 Bukit Timah Rd, Singapore 229899; E-mail: [email protected] The authors report no conflicts of interest. Copyright * 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000623
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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prefabricated titanium and PEEK cranioplasties with larger sample sizes and longer follow-up. Key Words: cranioplasty, polyetheretherketone, PEEK, titanium mesh, acrylic
& Volume 25, Number 2, March 2014
specific manner preoperatively from high-resolution computed tomography (CT) scans (Figs. 1 and 2). Excess temporalis muscle bulk was excised before the cranioplasty implants were fixed rigidly to the surrounding bone with standard plates and screws. A suction drain was placed in situ, and scalp wound closure was achieved via a layered approach for the galea aponeurotica and skin.
Perioperative Management
D
efects of the calvarium may be attributed to various etiologies including trauma, infection, neoplasms, or even an iatrogenic cause when a craniectomy is performed for evacuation of both intraaxial and extra-axial pathologies such as intracerebral hemorrhage, subdural and extradural hematomas, brain malignancies, and abscesses. The resultant loss of bony tissue and thus protection for the underlying brain can lead to considerable functional, aesthetic, and psychological disabilities.1 Previously, surgeons were less interested in reconstruction of the resultant bony defect after treatment of the underlying problem but increasingly, reestablishment of the contour and shape of the skull has evolved into one of the surgeon’s priorities.2 Moreover, there is increasing interest in cranioplasty as a treatment modality for neurologic recovery.3 Various reconstructive methods are available for restoration of cranial defects. From autologous bone to a multitude of alloplastic materials including gold, silver, titanium, acrylic resins, hydroxyapatite, and, more recently, polyetheretherketone (PEEK), the selection of implant material for cranioplasty depends on a complex interplay of the patient’s age, comorbid factors, defect site and size, and operator preference. Polyetheretherketone has, in recent years, emerged as one of the most promising alloplastic materials for calvarial reconstruction because of a number of desirable qualities including resistance to heat and ionizing radiation, biocompatibility and inertness, biomechanically similar to native bone, and nonmagnetizability for postoperative monitoring.4 Our study aimed to evaluate and compare the outcomes of cranioplasties performed with PEEK against titanium mesh only (one of the most widely used materials for alloplastic cranioplasty) and titanium mesh with acrylic cement (Ti-AC) reinforcement.
MATERIALS AND METHODS A retrospective review of all patients who underwent alloplastic cranioplasty by a single surgeon (I.N.) between January 2008 and December 2012 at Changi General Hospital, Singapore, was performed.
Patient Allocation of Implant Type Alloplastic cranioplasty was the only option for these patients because the storage of autologous bone grafts in the abdomen or freezers is not practiced in Singapore. Titanium mesh was initially used in all cases until PEEK was made available. Reinforcement of titanium mesh with polymethylmethacrylate, that is, acrylic cement, was decided intraoperatively by the operating surgeon. The result is 3 separate groups of patients categorized by implant type.
Antibiotic prophylaxis (1 g intravenous cefazolin) was administered both during anesthesia induction and every 8 hours postoperatively for 3 days. A plain CT scan of the head was also performed for routine, interval assessment of the implant on postoperative day (POD) 3.
Outcome Comparison and Statistics Clinical outcomes (in terms of postoperative wound-related complications, time interval between operation and complication, and deterioration of neurological function) of patients were noted both in the short-term (up to 28 days postoperatively) and long-term settings. Apart from the choice of cranioplasty material, the following parameters were also recorded: patient age and sex, medical history of patients, diagnosis necessitating cranioplasty, time interval between initial craniectomy and cranioplasty, duration of operation, size and location of calvarial defect, intraoperative complications, length of hospital stay, and length of follow-up period until complications were detected. Student t tests were utilized when comparing between 2 groups, whereas 1-way analysis of variance with Bonferroni post hoc tests were applied when more than 2 groups were involved. P G 0.05 was deemed significant.
RESULTS Twenty-four patients (75% were male; mean age, 41 years; range, 16Y67 years) underwent 24 delayed cranioplasties: 7 with Ti-AC, 5 with only a titanium mesh (Ti-only), and 12 with PEEK implants fitted. Titanium meshes were shaped and set intraoperatively. In contrast, no further contouring of PEEK implants was necessary during the procedure. The mean time interval between initial craniectomy and cranioplasty was 10 months (range, 3Y40 months), as summarized in Table 1. Two patients (patients 8 and 22) had a failed, prior primary attempt at calvarial reconstruction with autologous bone due to graft infection; there were no previous cranioplasty attempts in the other patients. None of the patients were diabetic or on long-term steroids or had radiotherapy previously, although 4 were chronic smokers. Subgroup analysis showed no significant difference (P 9 0.05) in terms of patient age, defect sizes, operative times, intraoperative complications, and duration of hospitalization between the 3 treatment groups. The average size of the cranial defect was 12 9 cm (range, 7 6 to 15 10 cm), and all were located unilaterally over the temporoparietal region except for 3 bifrontal reconstructions (2 Ti-AC, 1 Ti-only). Polyetheretherketone cranioplasties took on
Operative Technique The same surgical approach was used for all cranioplasties performed. After exposing the underlying cranial defect via incisions through the old craniectomy scar, dissection was carried out until bone was exposed all around. Care was taken to protect the integrity of the dura, and primary repairs were performed, as necessary, during dissection to obliterate any cerebrospinal fluid (CSF) leaks. Titanium meshes were fashioned intraoperatively over the cranial defect T reinforcement with acrylic cement; PEEK implants were designed in a patient- and defect-
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FIGURE 1. Three-dimensional reconstruction of preoperative CT scan. Left, Frontal view. Right, Side view.
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery
& Volume 25, Number 2, March 2014
Brief Clinical Studies
subsequent vancomycin-induced neutropenia, whereas patient 6 developed persistent urinary tract infections and pneumonia. The mean follow-up period was 11 months (range, 1Y32 months). Seven patients experienced postoperative wound breakdown: 3 (43% of Ti-AC patients) had Ti-AC implants, and 4 (80% of Ti-only patients) had Ti-only implants. Of these 7 patients, 5 had subsequent implant exposure (4 of whom required further plastic flap coverage), and 1 had CSF leakage. Ultimately, 6 of these 7 patients had their implant removed. The time interval between the operation and presentation of complications assumed a bimodal distribution, with the first peak at about 1 month postoperative and the second at approximately 20 months postoperative (Table 2); patients with PEEK cranioplasties performed had an otherwise uneventful postoperative course for a similar follow-up period except for 1 instance of an arguably, neurologically related complication as described previously for patient 24.
FIGURE 2. Computed tomography scans showing (A) focal dehiscent titanium mesh communicating with the overlying scalp at 20 months postoperative and (B) collection of fluid internal and external to titanium mesh cranial implant with rim enhancement and a few enhancing locules in another patient at 1 month postoperative, consistent with signs of clinical infection.
average 174 minutes compared with 207 and 162 for Ti-AC and Tionly, respectively. In 2 Ti-AC patients (patients 2 and 5), 1 Ti-only patient (patient 8), and 3 PEEK patients (patients 15, 17, and 23), primary dural repairs were necessitated because of inadvertent tears following dissection, but the resultant CSF leaks all resolved uneventfully. The scalp was closed primarily in all cases, and the average duration of surgery was 181 minutes (range, 100Y275 minutes). The mean length of hospital stay was 13 days (range, 4Y80 days), and 3 patients had prolonged hospitalization due to various reasons: patient 4 developed seizures on POD 1, and patient 24, while awaiting discharge placement, did so on POD 18. In both cases, however, repeat CT scans were unremarkable, and both patients have been fit-free since after starting antiepileptic medications. Patient 4 also had a prolonged stay due to methicillin-resistant Staphylococcus aureus wound infection and
DISCUSSION Calvarial defects most commonly result after cranial trauma and its attendant sequelae of intracranial bleeding.5 Often, treatment in the form of surgical decompression is the only way to save the patient’s life, but this comes at the expense of large skull bone segments that have to be removed. Cranioplasty for reconstruction of the resultant skull defect is thus carried out for both neurological protection and cosmesis, and a variety of implant materials can be used. In recent
TABLE 1. Details of Patients Undergoing Alloplastic Cranioplasty
Patient
Age, y
Sex
Diagnosis
Premorbid Factors
Material/Time to Cranioplasty, mo
Defect Size, cm
Surgery Time, min
Length of Stay, d
Follow-up, mo
1 2† 3 4 5 6† 7 8‡ 9 10 11 12† 13 14 15 16 17 18 19 20 21 22‡ 23 24 Average Ti-AC Ti-only PEEK Overall
50 40 39 44 59 46 25 21 34 38 64 18 48 36 16 39 57 38 56 67 21 33 52 55
Male Male Female Male Male Male Female Male Male Male Female Male Male Male Male Female Female Male Female Male Male Male Male Male
SDH EDH, SDH BG bleed SDH BG bleed SAH, SDH ICH, SDH EDH EDH, SDH BG bleed ICH SAH, SDH SDH BG bleed SDH BG bleed BG bleed ICH, SAH EDH SDH SDH, SAH EDH SDH BG bleed
No Smoking No No No No No No Smoking No No No No Smoking No No No Smoking No No No No No No
Ti-AC/8 Ti-AC/10 Ti-AC/9 Ti-AC/7 Ti-AC/10 Ti-AC/9 Ti-AC/4 Ti/25 Ti/8 Ti/5 Ti/15 Ti/9 PEEK/10 PEEK/10 PEEK/5 PEEK/40 PEEK/6 PEEK/10 PEEK/3 PEEK/5 PEEK/9 PEEK/9 PEEK/5 PEEK/3
13 9 10 15 11 8 12 10 97 21 7 11 10 98 97 13 9 8 12 20 7 11 10 11 9 14 8 10 8 10 8 11 9 11 8 12 9 10 8 76 11 10 12 8
145 240 155 275 235 220 180 110 175 195 140 190 210 175 195 185 165 150 200 125 185 100 240 160
10 7 11 41 14 80 4 6 4 4 7 10 6 4 6 10 5 10 7 9 6 8 15 29
26* 27 6 1* 1* 32 14 10 20* 1* 20* 14* 2 22 9 12 10 5 7 3 1 1 5 2
207 162 174 181
24 6 10 13
16 13 7 11
43 35 43 42
8 12 10 10
12 12 11 12
9 9 8 9
*Reported follow-up (in months) until complication detected. †Bifrontal reconstruction. ‡Previous autologous bone graft failure. BG indicates basal ganglia; EDH, extra-dural hematoma; ICH, intracerebral hemorrhage; SAH, subarachnoid hemorrhage; SDH, subdural hematoma.
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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TABLE 2. Postoperative Complications and Treatment After Alloplastic Cranioplasty Patient
Implant Type
Postoperative Complication
Date of Onset
Treatment
Ti-AC Ti-AC Ti-AC Ti Ti Ti Ti
Wound breakdown, implant exposure Wound breakdown, implant exposure Wound breakdown, implant exposure Wound breakdown Wound breakdown, CSF leak Wound breakdown, implant exposure Wound breakdown, implant exposure
26 mo Postoperative POD 34 POD 28 20 mo Postoperative POD 44 20 mo Postoperative 14 mo Postoperative
Implant removal, plastic flap cover Implant removal, plastic flap cover Implant removal, plastic flap cover Debridement, primary closure Implant removal, lumbar drain Implant removal, plastic flap cover Implant removal, primary closure
1 4 5 9 10 11 12* *Bifrontal reconstruction.
years, cranioplasty has also been reported to have a potential therapeutic role in neurological recovery via the restoration of cerebral hemodynamics.6 Although Lethaus et al7 recently reported their initial experience in 12 patients with prefabricated titanium and PEEK implants for cranioplasty, in contrast to the current study, there was little information about potentially confounding comorbidities such as smoking, diabetes mellitus, steroid usage, and radiotherapy. Moreover, the original pathology necessitating cranioplasty was also highly varied. Therefore, to the best of our knowledge, this is the largest study in the literature thus far to compare outcomes between titanium mesh and PEEK for delayed, alloplastic cranioplasty after initial craniectomy for cranial trauma.
Materials Titanium mesh has a long history of successful use as an implant material in alloplastic cranioplasty.8 It has been reported to be the implant material of choice for secondary cranioplasty following initial decompressive craniectomy after trauma,9 or where previous autologous bone grafts have failed.7 It has also been reported to have low complication rates (2.6%) of postoperative infection or impaired wound healing at up to 5 years’ follow-up.10 However, complications such as migration of the mesh through the skin even with intact skin coverage11 and postoperative extradural hematoma due to the permeability of the mesh12 have been reported. As such, various cements including hydroxyapatite and acrylic have been used in combination with the titanium mesh in an attempt to obliterate these gaps and thus potential complications. It is believed that the titanium mesh will, in these instances, serve as a stable scaffold to promote improved outcomes in cranioplasty through increased osseous integration (with hydroxyapatite) and better implant fixation (with acrylic).13,14 In contrast, PEEK has, in addition to the favorable characteristics as outlined previously, several properties that can overcome the disadvantages associated with titanium and acrylic. These are, namely, thermal nonconductivity (which prevents thermal damage to tissue and implant breakdown) and chemical inertness (avoiding the release of cytotoxins into brain tissue). However, PEEK does not have any bioactive potential unlike titanium, and its long-term stability is dependent on screw fixation and fibrosis. There is also little information available at present with regard to the long-term sequelae of PEEK implants for calvarial reconstruction.15
Operative Factors While patients who survive after decompressive craniectomy are usually obligated to undergo a cranioplasty procedure, infection rates of up to 11.3%, 10.2%, and 4.5% have been reported for autologous bone grafts,16 acrylic,17 and titanium implants,18 respectively. This may be accounted for by the time interval before cranioplasty and intraoperative factors such as the duration of surgery, defect size, and even choice of material. Depending on the
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cause, such complications may occur early (within 1 month postoperatively) or later. In our series, 3 (43%) of 7 patients with Ti-AC and 4 (80%) of 5 with Ti-only cranioplasties experienced wound breakdown. This complication occurred earlier in Ti-AC compared with Ti-only cranioplasties. Similar time intervals between craniectomy and cranioplasty, operative duration, and defect sizes between groups suggest that these factors are likely not accountable for this difference. We postulate that the most likely explanation for the bimodal distribution of complication occurrence is 2-fold. First, migration of the skin flap through the titanium mesh is most likely to have occurred as a late-onset complication, eventually leading to implant exposure. Second, reinforcement of the Ti-AC might have increased the risk of surrounding tissue necrosis and infection due to the toxic effect of the residual acrylic monomer. On the other hand, patients with PEEK cranioplasties have reported no wound-related complications since their operation. Follow-up periods in our study are not significantly different between titanium mesh and PEEK patient groups and are comparable to those used in other studies.3 This suggests that PEEK is superior to titanium mesh (with or without acrylic cement) as a material for cranioplasty in terms of complication risks.
Critique of Current Study Titanium mesh only and Ti-AC implants were fashioned intraoperatively in our study as opposed to PEEK cranioplasties, which were predesigned using computer-aided modeling. This could have affected the difference in complication risk because polymerization of polymethylmethacrylate is heavily exothermic, reaching temperatures in excess of 100-CVmore than sufficient to necrose surrounding tissue and cause implant failure.19 Preoperative computer-aided fabrication of Ti-AC and Ti-only implants could have removed this methodology bias. Our study did not report a significant difference in operative duration between PEEK (designed preoperatively using computer modeling) and titanium mesh cranioplasties (fashioned intraoperatively) as expected.20 We postulate that the surgical team’s considerably less experience with PEEK (due to its more recent introduction) and small sample sizes could be accountable, leading to underestimation of the true operative duration. Despite these limitations, the current study is important because it highlighted significantly higher complication rates with titanium mesh than with PEEK. In conclusion, our early results suggest that PEEK might eventually supersede titanium and acrylic to become the alloplastic material of choice for cranioplasty because of its lower complication rates. However, the long-term sequelae of PEEK implants as yet remain unknown. Therefore, further comparative studies including randomized trials between titanium mesh and PEEK using computer-aided design for alloplastic cranioplasty with appropriate follow-up periods are important to help determine the cost-benefit analysis associated with each implant material. * 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery
& Volume 25, Number 2, March 2014
REFERENCES 1. Scolozzi P, Martinez A, Jaques B. Complex orbito-fronto-temporal reconstruction using computer-designed PEEK implant. J Craniofac Surg 2007;18:224Y228 2. Habal MB. Bone tissue engineering applications in craniofacial reconstructive surgery. Clin Plast Surg 2004;31:387Y392 3. Suzuki N, Suzuki S, Iwabuchi T. Neurological improvement after cranioplasty. Analysis by dynamic CT scan. Acta Neurochir (Wien) 1993;122:49Y53 4. Hanasono MM, Goel N, DeMonte F. Calvarial reconstruction with polyetheretherketone implants. Ann Plast Surg 2009;62:653Y655 5. Sahoo N, Roy ID, Desai AP, et al. Comparative evaluation of autogenous calvarial bone graft and alloplastic materials for secondary reconstruction of cranial defects. J Craniofac Surg 2010;21:79Y82 6. Richaud J, Boetto S, Guell A, et al. Effects of cranioplasty on neurological function and cerebral blood flow [in French]. Neurochirurgie 1985;31:183Y188 7. Lethaus B, Ter Laak MP, Laeven P, et al. A treatment algorithm for patients with large skull bone defects and first results. J Craniomaxillofac Surg 2011;39:435Y440 8. Janecka IP. New reconstructive technologies in skull base surgery: role of titanium mesh and porous polyethylene. Arch Otolaryngol Head Neck Surg 2000;126:396Y401 9. Cabraja M, Klein M, Lehmann TN. Long-term results following titanium cranioplasty of large skull defects. Neurosurg Focus 2009;26:E10 10. Matsuno A, Tanaka H, Iwamuro H, et al. Analyses of the factors influencing bone graft infection after delayed cranioplasty. Acta Neurochir (Wien) 2006;148:535Y540 11. Maier W. Biomaterials in skull base surgery. GMS Curr Top Otorhinolaryngol Head Neck Surg 2009;8:Doc07 12. Martin MP, Olson S. Post-operative complications with titanium mesh. J Clin Neurosci 2009;16:1080Y1081 13. Ducic Y. Titanium mesh and hydroxyapatite cement cranioplasty: a report of 20 cases. J Oral Maxillofac Surg 2002;60:272Y276 14. Malis LI. Titanium mesh and acrylic cranioplasty. Neurosurgery 1989;25:351Y355 15. Li LH, Kim HW, Lee SH, et al. Biocompatibility of titanium implants modified by microarc oxidation and hydroxyapatite coating. J Biomed Mater Res A 2005;73:48Y54 16. Gooch MR, Gin GE, Kenning TJ, et al. Complications of cranioplasty following decompressive craniectomy: analysis of 62 cases. Neurosurg Focus 2009;26:E9 17. Marchac D, Greensmith A. Long-term experience with methylmethacrylate cranioplasty in craniofacial surgery. J Plast Reconstr Aesthet Surg 2008;61:744Y752 18. Blake GB, MacFarlane MR, Hinton JW. Titanium in reconstructive surgery of the skull and face. Br J Plast Surg 1990;43:528Y535 19. Redfern RM, Pu¨lhorn H. Cranioplasty. Advances Clin Neurosci Rehab 2007;7:32Y34 20. Dean D, Min KJ, Bond A. Computer aided design of large-format prefabricated cranial plates. J Craniofac Surg 2003;14:819Y832
Lipoblastoma of the Hand and Cleft Palate: Is There a Genetic Association? Michael Alperovich, MD, Diego Ayo, MD, David A. Staffenberg, MD, Sheel Sharma, MD Abstract: We report a case of lipoblastoma of the hand in a 19-monthold female patient with a history of cleft palate. The incidence of lipoblastoma and cleft palate individually is extremely rare. To the best of our knowledge, only 1 other case of a patient with both cleft palate
Brief Clinical Studies
and lipoblastoma exists in the literature. Lipoblastoma is a rare benign neoplasm in adipose tissue almost exclusively found in children younger than 3 years. Cytogenetic testing has shown that lipoblastomas characteristically share a clonal chromosomal rearrangement affecting the long arm of chromosome 8. Furthermore, recent research has shown that the 8q chromosome is an important genetic risk factor for cleft palate development. We describe the second case linking cleft palate with this rare tumor and provide evidence for a potential genetic association. Key Words: Lipoblastoma, cleft palate, genetic association
C
left palate is a result of aberrant embryologic development and results in difficulty with speech and feeding. The incidence of cleft palate is 1 in 2000 live births.1 It is estimated that 50% of cleft palateYonly cases are nonsyndromic.2 Multiple chromosomal loci historically have been associated with cleft palate, including chromosomes 1, 2, 4, 6, 11, 14, 17, and 19.1 Cleft lip and palate affects 1 in 700 live births, with higher incidences in certain geographic, racial, and ethnic groups.2 The higher rates in some populations suggest a similar genetic predisposition that can increase susceptibility. Lipoblastoma is a rare pediatric tumor of adipose tissue with approximately 90% of cases occurring in children younger than 3 years.3,4 Lipoblastoma classically presents as a painless rapidly enlarging mass and is most commonly found in the trunk, neck, and extremities.3,4 The term lipoblastoma was first described by Jaffe5 in 1926 to describe recurrent tumors of the groin. The term lipoblastomatosis was coined in 1958 to describe a benign neoplasm of fetal adipose tissue.6 In 1973, Chung and Enzinger4 further classified this entity into a circumscribed form and a diffuse type designated as benign lipoblastoma and benign lipoblastomatosis, respectively. No cases of metastasis have been reported.3,7 The treatment of choice involves complete but conservative local excision.3,4 The recurrence rate is 14% and usually associated with incomplete excision.3,4 Cytogenetic testing has found that lipoblastomas have characteristic clonal chromosomal rearrangements affecting chromosome 8q.3,7,8 An oncogene named PLAG1 resides in the long arm of chromosome 8 and is hypothesized to be related to lipoblastoma development.8 In a genetic study of 16 lipoblastomas, 11 had rearrangements of the 8q12 PLAG1 region, and 3 had polysomy for chromosome 8 in the absence of PLAG1 rearrangement.9 Another study described 14 cases of lipoblastoma with nonrandom rearrangement involving 8q11-q24.10
CLINICAL REPORT The patient is a 19-month-old girl with a history of a Veau class II cleft palate, ventricular septal defect, hypotonia, and recurrent otitis media. From the Department of Plastic Surgery, New York University Medical Center, New York, New York. Received October 5, 2013. Accepted for publication December 2, 2013. Address correspondence and reprint requests to Michael Alperovich, MD, Department of Plastic Surgery, New York University Medical Center, 307 East 33rd St, New York, NY 10016; E-mail: [email protected] The authors report no conflicts of interest. Copyright * 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000628
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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TABLE 3. Types of Diplopia According to Symptomatic Orbital Wall Fractures in the Study Population All Directions Floor 62 (79.2%) Medial wall 9 (11.7%) Lateral wall 1 (1.3%) Floor + 6 (7.8%) medial wall Floor + 0 lateral wall Total 78
Elevation and Depression 56 (86.1%) 2 (3.1%) 0 7 (10.8%)
Elevation
Depression Horizontal
53* (93%) 14 (87.6%) 4 (36.4%) 1 (1.7%) 1 (6.2%) 7† (63.6%) 0 0 0 3 (5.3%) 1 (6.2%) 0
0
0
0
0
65
57
16
11
*P G 0.05. †P G 0.000005.
Brief Clinical Studies
Computer-Designed Polyetheretherketone Implants Versus Titanium Mesh (TAcrylic Cement) in Alloplastic Cranioplasty: A Retrospective Single-Surgeon, Single-Center Study Zhi Yang Ng, MBChB,* Wei Jie Jensen Ang, BMedSci(Hons),Þ Irfan Nawaz, MBBS, FRCSþ
between horizontal diplopia and medial wall fractures (P G 0.000005) (Table 3).
CONCLUSIONS Our findings suggest that, in patients under evaluation for orbital trauma, the observation of diplopia on eye elevation and horizontal diplopia at presentation could be useful clinical indicators orbital floor and medial wall fractures, respectively. As the clinical investigation still remains an important indicator for open surgery, together with the radiologic investigation, posttraumatic orbital clinical signs should be precisely assessed to help in the diagnosis and surgical planning.
REFERENCES 1. Bagheri SC, Dierks EJ, Kademani D, et al. Application of a facial injury severity scale in craniomaxillofacial trauma. J Oral Maxillofac Surg 2006;64:408Y414 2. Folkestad L, Lindgren G, Moller C, et al. Diplopia in orbital fractures: a simple method to evaluate eye motility. Acta Otolaryngol 2007;127:156Y166 3. Gosse EM, Ferguson AW, Lymburn EG, et al. Blow-out fractures: patterns of ocular motility and effect of surgical repair. Br J Oral Maxillofac Surg 2010;48:40Y43 4. Jank S, Schuchter B, Emshoff R, et al. Clinical signs of orbital wall fractures as a function of anatomic location. Oral Surg Oral Med Oral Pathol Oral Radiol Endod 2003;96:149Y153 5. Lee SH, Lew H, Yun YS. Ocular motility disturbances in orbital wall fracture patients. Yonsei Med J 2005;46:359Y367 6. Park MS, Kim YJ, Kim H, et al. Prevalence of diplopia and extraocular movement limitation according to the location of isolated pure blowout fractures. Arch Plast Surg 2012;39:204Y208 7. Roccia F, Boffano P, Guglielmi V, et al. Role of the maxillofacial surgeon in the management of severe ocular injuries after maxillofacial fractures. J Emerg Trauma Shock 2011;4:188Y193 8. Vriens JP, Moos KF. Morbidity of the infraorbital nerve following orbitozygomatic complex fractures. J Craniomaxillofac Surg 1995;23:363Y368 9. Boffano P, Roccia F, Gallesio C, et al. Bicycle-related maxillofacial injuries: a double-center study. Oral Surg Oral Med Oral Pathol Oral Radiol 2013;116:275Y280 10. Roccia F, Boffano P, Bianchi FA, et al. Maxillofacial injuries due to work-related accidents in the North West of Italy. Oral Maxillofac Surg 2013;17:181Y186
Background: Polyetheretherketone (PEEK) has emerged as one of the most promising alloplastic materials for calvarial reconstruction because of a number of desirable qualities including resistance to heat and ionizing radiation, biocompatibility, biomechanically similar to native bone, and being nonferromagnetic for postoperative monitoring. We aimed to evaluate and compare the outcomes of alloplastic cranioplasty performed with PEEK, titanium mesh only (Ti-only), and titanium mesh with acrylic cement (Ti-AC); titanium mesh has previously recorded many successes with low complication rates. Methods: A retrospective, single-surgeon, single-center study for alloplastic cranioplasties was performed between January 2008 and December 2012. Titanium meshes were fashioned intraoperatively, whereas PEEK implants were prefabricated from high-resolution computed tomography scans. Patients were routinely followed up in outpatient settings. Results: Twenty-four patients (75% male) underwent delayed cranioplasty following initial craniectomy. Four Ti-only and 3 Ti-AC patients had postoperative complications including wound breakdown and implant exposure. These assumed a bimodal distribution with time postoperatively and culminated in implant removal in 6 patients, of which 4 required further plastic flap coverage. Subgroup analysis showed no significant differences in predictive factors apart from cranioplasty material with means as follows: age = 42 years, interval to surgery = 10 months, defect size = 12 9 cm, operation duration = 181 minutes, hospital stay = 13 days, follow-up = 11 months. Conclusions: Early results suggest that PEEK may be superior to Ti-only or Ti-AC as an alloplastic cranioplasty choice. Further research should include randomized trials between computer-aided,
From the *Department of Plastic Reconstructive and Aesthetic Surgery, KK Women’s and Children’s Hospital, Singapore; †College of Medicine and Veterinary Medicine, University of Edinburgh, Scotland, United Kingdom; and ‡Division of Neurosurgery, Changi General Hospital, Singapore. Received September 23, 2013. Accepted for publication December 2, 2013. Address correspondence and reprint requests to Zhi Yang Ng, MBChB, Department of Plastic Reconstructive and Aesthetic Surgery, KK Women’s and Children’s Hospital, 100 Bukit Timah Rd, Singapore 229899; E-mail: [email protected] The authors report no conflicts of interest. Copyright * 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000623
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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prefabricated titanium and PEEK cranioplasties with larger sample sizes and longer follow-up. Key Words: cranioplasty, polyetheretherketone, PEEK, titanium mesh, acrylic
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specific manner preoperatively from high-resolution computed tomography (CT) scans (Figs. 1 and 2). Excess temporalis muscle bulk was excised before the cranioplasty implants were fixed rigidly to the surrounding bone with standard plates and screws. A suction drain was placed in situ, and scalp wound closure was achieved via a layered approach for the galea aponeurotica and skin.
Perioperative Management
D
efects of the calvarium may be attributed to various etiologies including trauma, infection, neoplasms, or even an iatrogenic cause when a craniectomy is performed for evacuation of both intraaxial and extra-axial pathologies such as intracerebral hemorrhage, subdural and extradural hematomas, brain malignancies, and abscesses. The resultant loss of bony tissue and thus protection for the underlying brain can lead to considerable functional, aesthetic, and psychological disabilities.1 Previously, surgeons were less interested in reconstruction of the resultant bony defect after treatment of the underlying problem but increasingly, reestablishment of the contour and shape of the skull has evolved into one of the surgeon’s priorities.2 Moreover, there is increasing interest in cranioplasty as a treatment modality for neurologic recovery.3 Various reconstructive methods are available for restoration of cranial defects. From autologous bone to a multitude of alloplastic materials including gold, silver, titanium, acrylic resins, hydroxyapatite, and, more recently, polyetheretherketone (PEEK), the selection of implant material for cranioplasty depends on a complex interplay of the patient’s age, comorbid factors, defect site and size, and operator preference. Polyetheretherketone has, in recent years, emerged as one of the most promising alloplastic materials for calvarial reconstruction because of a number of desirable qualities including resistance to heat and ionizing radiation, biocompatibility and inertness, biomechanically similar to native bone, and nonmagnetizability for postoperative monitoring.4 Our study aimed to evaluate and compare the outcomes of cranioplasties performed with PEEK against titanium mesh only (one of the most widely used materials for alloplastic cranioplasty) and titanium mesh with acrylic cement (Ti-AC) reinforcement.
MATERIALS AND METHODS A retrospective review of all patients who underwent alloplastic cranioplasty by a single surgeon (I.N.) between January 2008 and December 2012 at Changi General Hospital, Singapore, was performed.
Patient Allocation of Implant Type Alloplastic cranioplasty was the only option for these patients because the storage of autologous bone grafts in the abdomen or freezers is not practiced in Singapore. Titanium mesh was initially used in all cases until PEEK was made available. Reinforcement of titanium mesh with polymethylmethacrylate, that is, acrylic cement, was decided intraoperatively by the operating surgeon. The result is 3 separate groups of patients categorized by implant type.
Antibiotic prophylaxis (1 g intravenous cefazolin) was administered both during anesthesia induction and every 8 hours postoperatively for 3 days. A plain CT scan of the head was also performed for routine, interval assessment of the implant on postoperative day (POD) 3.
Outcome Comparison and Statistics Clinical outcomes (in terms of postoperative wound-related complications, time interval between operation and complication, and deterioration of neurological function) of patients were noted both in the short-term (up to 28 days postoperatively) and long-term settings. Apart from the choice of cranioplasty material, the following parameters were also recorded: patient age and sex, medical history of patients, diagnosis necessitating cranioplasty, time interval between initial craniectomy and cranioplasty, duration of operation, size and location of calvarial defect, intraoperative complications, length of hospital stay, and length of follow-up period until complications were detected. Student t tests were utilized when comparing between 2 groups, whereas 1-way analysis of variance with Bonferroni post hoc tests were applied when more than 2 groups were involved. P G 0.05 was deemed significant.
RESULTS Twenty-four patients (75% were male; mean age, 41 years; range, 16Y67 years) underwent 24 delayed cranioplasties: 7 with Ti-AC, 5 with only a titanium mesh (Ti-only), and 12 with PEEK implants fitted. Titanium meshes were shaped and set intraoperatively. In contrast, no further contouring of PEEK implants was necessary during the procedure. The mean time interval between initial craniectomy and cranioplasty was 10 months (range, 3Y40 months), as summarized in Table 1. Two patients (patients 8 and 22) had a failed, prior primary attempt at calvarial reconstruction with autologous bone due to graft infection; there were no previous cranioplasty attempts in the other patients. None of the patients were diabetic or on long-term steroids or had radiotherapy previously, although 4 were chronic smokers. Subgroup analysis showed no significant difference (P 9 0.05) in terms of patient age, defect sizes, operative times, intraoperative complications, and duration of hospitalization between the 3 treatment groups. The average size of the cranial defect was 12 9 cm (range, 7 6 to 15 10 cm), and all were located unilaterally over the temporoparietal region except for 3 bifrontal reconstructions (2 Ti-AC, 1 Ti-only). Polyetheretherketone cranioplasties took on
Operative Technique The same surgical approach was used for all cranioplasties performed. After exposing the underlying cranial defect via incisions through the old craniectomy scar, dissection was carried out until bone was exposed all around. Care was taken to protect the integrity of the dura, and primary repairs were performed, as necessary, during dissection to obliterate any cerebrospinal fluid (CSF) leaks. Titanium meshes were fashioned intraoperatively over the cranial defect T reinforcement with acrylic cement; PEEK implants were designed in a patient- and defect-
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FIGURE 1. Three-dimensional reconstruction of preoperative CT scan. Left, Frontal view. Right, Side view.
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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subsequent vancomycin-induced neutropenia, whereas patient 6 developed persistent urinary tract infections and pneumonia. The mean follow-up period was 11 months (range, 1Y32 months). Seven patients experienced postoperative wound breakdown: 3 (43% of Ti-AC patients) had Ti-AC implants, and 4 (80% of Ti-only patients) had Ti-only implants. Of these 7 patients, 5 had subsequent implant exposure (4 of whom required further plastic flap coverage), and 1 had CSF leakage. Ultimately, 6 of these 7 patients had their implant removed. The time interval between the operation and presentation of complications assumed a bimodal distribution, with the first peak at about 1 month postoperative and the second at approximately 20 months postoperative (Table 2); patients with PEEK cranioplasties performed had an otherwise uneventful postoperative course for a similar follow-up period except for 1 instance of an arguably, neurologically related complication as described previously for patient 24.
FIGURE 2. Computed tomography scans showing (A) focal dehiscent titanium mesh communicating with the overlying scalp at 20 months postoperative and (B) collection of fluid internal and external to titanium mesh cranial implant with rim enhancement and a few enhancing locules in another patient at 1 month postoperative, consistent with signs of clinical infection.
average 174 minutes compared with 207 and 162 for Ti-AC and Tionly, respectively. In 2 Ti-AC patients (patients 2 and 5), 1 Ti-only patient (patient 8), and 3 PEEK patients (patients 15, 17, and 23), primary dural repairs were necessitated because of inadvertent tears following dissection, but the resultant CSF leaks all resolved uneventfully. The scalp was closed primarily in all cases, and the average duration of surgery was 181 minutes (range, 100Y275 minutes). The mean length of hospital stay was 13 days (range, 4Y80 days), and 3 patients had prolonged hospitalization due to various reasons: patient 4 developed seizures on POD 1, and patient 24, while awaiting discharge placement, did so on POD 18. In both cases, however, repeat CT scans were unremarkable, and both patients have been fit-free since after starting antiepileptic medications. Patient 4 also had a prolonged stay due to methicillin-resistant Staphylococcus aureus wound infection and
DISCUSSION Calvarial defects most commonly result after cranial trauma and its attendant sequelae of intracranial bleeding.5 Often, treatment in the form of surgical decompression is the only way to save the patient’s life, but this comes at the expense of large skull bone segments that have to be removed. Cranioplasty for reconstruction of the resultant skull defect is thus carried out for both neurological protection and cosmesis, and a variety of implant materials can be used. In recent
TABLE 1. Details of Patients Undergoing Alloplastic Cranioplasty
Patient
Age, y
Sex
Diagnosis
Premorbid Factors
Material/Time to Cranioplasty, mo
Defect Size, cm
Surgery Time, min
Length of Stay, d
Follow-up, mo
1 2† 3 4 5 6† 7 8‡ 9 10 11 12† 13 14 15 16 17 18 19 20 21 22‡ 23 24 Average Ti-AC Ti-only PEEK Overall
50 40 39 44 59 46 25 21 34 38 64 18 48 36 16 39 57 38 56 67 21 33 52 55
Male Male Female Male Male Male Female Male Male Male Female Male Male Male Male Female Female Male Female Male Male Male Male Male
SDH EDH, SDH BG bleed SDH BG bleed SAH, SDH ICH, SDH EDH EDH, SDH BG bleed ICH SAH, SDH SDH BG bleed SDH BG bleed BG bleed ICH, SAH EDH SDH SDH, SAH EDH SDH BG bleed
No Smoking No No No No No No Smoking No No No No Smoking No No No Smoking No No No No No No
Ti-AC/8 Ti-AC/10 Ti-AC/9 Ti-AC/7 Ti-AC/10 Ti-AC/9 Ti-AC/4 Ti/25 Ti/8 Ti/5 Ti/15 Ti/9 PEEK/10 PEEK/10 PEEK/5 PEEK/40 PEEK/6 PEEK/10 PEEK/3 PEEK/5 PEEK/9 PEEK/9 PEEK/5 PEEK/3
13 9 10 15 11 8 12 10 97 21 7 11 10 98 97 13 9 8 12 20 7 11 10 11 9 14 8 10 8 10 8 11 9 11 8 12 9 10 8 76 11 10 12 8
145 240 155 275 235 220 180 110 175 195 140 190 210 175 195 185 165 150 200 125 185 100 240 160
10 7 11 41 14 80 4 6 4 4 7 10 6 4 6 10 5 10 7 9 6 8 15 29
26* 27 6 1* 1* 32 14 10 20* 1* 20* 14* 2 22 9 12 10 5 7 3 1 1 5 2
207 162 174 181
24 6 10 13
16 13 7 11
43 35 43 42
8 12 10 10
12 12 11 12
9 9 8 9
*Reported follow-up (in months) until complication detected. †Bifrontal reconstruction. ‡Previous autologous bone graft failure. BG indicates basal ganglia; EDH, extra-dural hematoma; ICH, intracerebral hemorrhage; SAH, subarachnoid hemorrhage; SDH, subdural hematoma.
* 2014 Mutaz B. Habal, MD
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TABLE 2. Postoperative Complications and Treatment After Alloplastic Cranioplasty Patient
Implant Type
Postoperative Complication
Date of Onset
Treatment
Ti-AC Ti-AC Ti-AC Ti Ti Ti Ti
Wound breakdown, implant exposure Wound breakdown, implant exposure Wound breakdown, implant exposure Wound breakdown Wound breakdown, CSF leak Wound breakdown, implant exposure Wound breakdown, implant exposure
26 mo Postoperative POD 34 POD 28 20 mo Postoperative POD 44 20 mo Postoperative 14 mo Postoperative
Implant removal, plastic flap cover Implant removal, plastic flap cover Implant removal, plastic flap cover Debridement, primary closure Implant removal, lumbar drain Implant removal, plastic flap cover Implant removal, primary closure
1 4 5 9 10 11 12* *Bifrontal reconstruction.
years, cranioplasty has also been reported to have a potential therapeutic role in neurological recovery via the restoration of cerebral hemodynamics.6 Although Lethaus et al7 recently reported their initial experience in 12 patients with prefabricated titanium and PEEK implants for cranioplasty, in contrast to the current study, there was little information about potentially confounding comorbidities such as smoking, diabetes mellitus, steroid usage, and radiotherapy. Moreover, the original pathology necessitating cranioplasty was also highly varied. Therefore, to the best of our knowledge, this is the largest study in the literature thus far to compare outcomes between titanium mesh and PEEK for delayed, alloplastic cranioplasty after initial craniectomy for cranial trauma.
Materials Titanium mesh has a long history of successful use as an implant material in alloplastic cranioplasty.8 It has been reported to be the implant material of choice for secondary cranioplasty following initial decompressive craniectomy after trauma,9 or where previous autologous bone grafts have failed.7 It has also been reported to have low complication rates (2.6%) of postoperative infection or impaired wound healing at up to 5 years’ follow-up.10 However, complications such as migration of the mesh through the skin even with intact skin coverage11 and postoperative extradural hematoma due to the permeability of the mesh12 have been reported. As such, various cements including hydroxyapatite and acrylic have been used in combination with the titanium mesh in an attempt to obliterate these gaps and thus potential complications. It is believed that the titanium mesh will, in these instances, serve as a stable scaffold to promote improved outcomes in cranioplasty through increased osseous integration (with hydroxyapatite) and better implant fixation (with acrylic).13,14 In contrast, PEEK has, in addition to the favorable characteristics as outlined previously, several properties that can overcome the disadvantages associated with titanium and acrylic. These are, namely, thermal nonconductivity (which prevents thermal damage to tissue and implant breakdown) and chemical inertness (avoiding the release of cytotoxins into brain tissue). However, PEEK does not have any bioactive potential unlike titanium, and its long-term stability is dependent on screw fixation and fibrosis. There is also little information available at present with regard to the long-term sequelae of PEEK implants for calvarial reconstruction.15
Operative Factors While patients who survive after decompressive craniectomy are usually obligated to undergo a cranioplasty procedure, infection rates of up to 11.3%, 10.2%, and 4.5% have been reported for autologous bone grafts,16 acrylic,17 and titanium implants,18 respectively. This may be accounted for by the time interval before cranioplasty and intraoperative factors such as the duration of surgery, defect size, and even choice of material. Depending on the
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cause, such complications may occur early (within 1 month postoperatively) or later. In our series, 3 (43%) of 7 patients with Ti-AC and 4 (80%) of 5 with Ti-only cranioplasties experienced wound breakdown. This complication occurred earlier in Ti-AC compared with Ti-only cranioplasties. Similar time intervals between craniectomy and cranioplasty, operative duration, and defect sizes between groups suggest that these factors are likely not accountable for this difference. We postulate that the most likely explanation for the bimodal distribution of complication occurrence is 2-fold. First, migration of the skin flap through the titanium mesh is most likely to have occurred as a late-onset complication, eventually leading to implant exposure. Second, reinforcement of the Ti-AC might have increased the risk of surrounding tissue necrosis and infection due to the toxic effect of the residual acrylic monomer. On the other hand, patients with PEEK cranioplasties have reported no wound-related complications since their operation. Follow-up periods in our study are not significantly different between titanium mesh and PEEK patient groups and are comparable to those used in other studies.3 This suggests that PEEK is superior to titanium mesh (with or without acrylic cement) as a material for cranioplasty in terms of complication risks.
Critique of Current Study Titanium mesh only and Ti-AC implants were fashioned intraoperatively in our study as opposed to PEEK cranioplasties, which were predesigned using computer-aided modeling. This could have affected the difference in complication risk because polymerization of polymethylmethacrylate is heavily exothermic, reaching temperatures in excess of 100-CVmore than sufficient to necrose surrounding tissue and cause implant failure.19 Preoperative computer-aided fabrication of Ti-AC and Ti-only implants could have removed this methodology bias. Our study did not report a significant difference in operative duration between PEEK (designed preoperatively using computer modeling) and titanium mesh cranioplasties (fashioned intraoperatively) as expected.20 We postulate that the surgical team’s considerably less experience with PEEK (due to its more recent introduction) and small sample sizes could be accountable, leading to underestimation of the true operative duration. Despite these limitations, the current study is important because it highlighted significantly higher complication rates with titanium mesh than with PEEK. In conclusion, our early results suggest that PEEK might eventually supersede titanium and acrylic to become the alloplastic material of choice for cranioplasty because of its lower complication rates. However, the long-term sequelae of PEEK implants as yet remain unknown. Therefore, further comparative studies including randomized trials between titanium mesh and PEEK using computer-aided design for alloplastic cranioplasty with appropriate follow-up periods are important to help determine the cost-benefit analysis associated with each implant material. * 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
The Journal of Craniofacial Surgery
& Volume 25, Number 2, March 2014
REFERENCES 1. Scolozzi P, Martinez A, Jaques B. Complex orbito-fronto-temporal reconstruction using computer-designed PEEK implant. J Craniofac Surg 2007;18:224Y228 2. Habal MB. Bone tissue engineering applications in craniofacial reconstructive surgery. Clin Plast Surg 2004;31:387Y392 3. Suzuki N, Suzuki S, Iwabuchi T. Neurological improvement after cranioplasty. Analysis by dynamic CT scan. Acta Neurochir (Wien) 1993;122:49Y53 4. Hanasono MM, Goel N, DeMonte F. Calvarial reconstruction with polyetheretherketone implants. Ann Plast Surg 2009;62:653Y655 5. Sahoo N, Roy ID, Desai AP, et al. Comparative evaluation of autogenous calvarial bone graft and alloplastic materials for secondary reconstruction of cranial defects. J Craniofac Surg 2010;21:79Y82 6. Richaud J, Boetto S, Guell A, et al. Effects of cranioplasty on neurological function and cerebral blood flow [in French]. Neurochirurgie 1985;31:183Y188 7. Lethaus B, Ter Laak MP, Laeven P, et al. A treatment algorithm for patients with large skull bone defects and first results. J Craniomaxillofac Surg 2011;39:435Y440 8. Janecka IP. New reconstructive technologies in skull base surgery: role of titanium mesh and porous polyethylene. Arch Otolaryngol Head Neck Surg 2000;126:396Y401 9. Cabraja M, Klein M, Lehmann TN. Long-term results following titanium cranioplasty of large skull defects. Neurosurg Focus 2009;26:E10 10. Matsuno A, Tanaka H, Iwamuro H, et al. Analyses of the factors influencing bone graft infection after delayed cranioplasty. Acta Neurochir (Wien) 2006;148:535Y540 11. Maier W. Biomaterials in skull base surgery. GMS Curr Top Otorhinolaryngol Head Neck Surg 2009;8:Doc07 12. Martin MP, Olson S. Post-operative complications with titanium mesh. J Clin Neurosci 2009;16:1080Y1081 13. Ducic Y. Titanium mesh and hydroxyapatite cement cranioplasty: a report of 20 cases. J Oral Maxillofac Surg 2002;60:272Y276 14. Malis LI. Titanium mesh and acrylic cranioplasty. Neurosurgery 1989;25:351Y355 15. Li LH, Kim HW, Lee SH, et al. Biocompatibility of titanium implants modified by microarc oxidation and hydroxyapatite coating. J Biomed Mater Res A 2005;73:48Y54 16. Gooch MR, Gin GE, Kenning TJ, et al. Complications of cranioplasty following decompressive craniectomy: analysis of 62 cases. Neurosurg Focus 2009;26:E9 17. Marchac D, Greensmith A. Long-term experience with methylmethacrylate cranioplasty in craniofacial surgery. J Plast Reconstr Aesthet Surg 2008;61:744Y752 18. Blake GB, MacFarlane MR, Hinton JW. Titanium in reconstructive surgery of the skull and face. Br J Plast Surg 1990;43:528Y535 19. Redfern RM, Pu¨lhorn H. Cranioplasty. Advances Clin Neurosci Rehab 2007;7:32Y34 20. Dean D, Min KJ, Bond A. Computer aided design of large-format prefabricated cranial plates. J Craniofac Surg 2003;14:819Y832
Lipoblastoma of the Hand and Cleft Palate: Is There a Genetic Association? Michael Alperovich, MD, Diego Ayo, MD, David A. Staffenberg, MD, Sheel Sharma, MD Abstract: We report a case of lipoblastoma of the hand in a 19-monthold female patient with a history of cleft palate. The incidence of lipoblastoma and cleft palate individually is extremely rare. To the best of our knowledge, only 1 other case of a patient with both cleft palate
Brief Clinical Studies
and lipoblastoma exists in the literature. Lipoblastoma is a rare benign neoplasm in adipose tissue almost exclusively found in children younger than 3 years. Cytogenetic testing has shown that lipoblastomas characteristically share a clonal chromosomal rearrangement affecting the long arm of chromosome 8. Furthermore, recent research has shown that the 8q chromosome is an important genetic risk factor for cleft palate development. We describe the second case linking cleft palate with this rare tumor and provide evidence for a potential genetic association. Key Words: Lipoblastoma, cleft palate, genetic association
C
left palate is a result of aberrant embryologic development and results in difficulty with speech and feeding. The incidence of cleft palate is 1 in 2000 live births.1 It is estimated that 50% of cleft palateYonly cases are nonsyndromic.2 Multiple chromosomal loci historically have been associated with cleft palate, including chromosomes 1, 2, 4, 6, 11, 14, 17, and 19.1 Cleft lip and palate affects 1 in 700 live births, with higher incidences in certain geographic, racial, and ethnic groups.2 The higher rates in some populations suggest a similar genetic predisposition that can increase susceptibility. Lipoblastoma is a rare pediatric tumor of adipose tissue with approximately 90% of cases occurring in children younger than 3 years.3,4 Lipoblastoma classically presents as a painless rapidly enlarging mass and is most commonly found in the trunk, neck, and extremities.3,4 The term lipoblastoma was first described by Jaffe5 in 1926 to describe recurrent tumors of the groin. The term lipoblastomatosis was coined in 1958 to describe a benign neoplasm of fetal adipose tissue.6 In 1973, Chung and Enzinger4 further classified this entity into a circumscribed form and a diffuse type designated as benign lipoblastoma and benign lipoblastomatosis, respectively. No cases of metastasis have been reported.3,7 The treatment of choice involves complete but conservative local excision.3,4 The recurrence rate is 14% and usually associated with incomplete excision.3,4 Cytogenetic testing has found that lipoblastomas have characteristic clonal chromosomal rearrangements affecting chromosome 8q.3,7,8 An oncogene named PLAG1 resides in the long arm of chromosome 8 and is hypothesized to be related to lipoblastoma development.8 In a genetic study of 16 lipoblastomas, 11 had rearrangements of the 8q12 PLAG1 region, and 3 had polysomy for chromosome 8 in the absence of PLAG1 rearrangement.9 Another study described 14 cases of lipoblastoma with nonrandom rearrangement involving 8q11-q24.10
CLINICAL REPORT The patient is a 19-month-old girl with a history of a Veau class II cleft palate, ventricular septal defect, hypotonia, and recurrent otitis media. From the Department of Plastic Surgery, New York University Medical Center, New York, New York. Received October 5, 2013. Accepted for publication December 2, 2013. Address correspondence and reprint requests to Michael Alperovich, MD, Department of Plastic Surgery, New York University Medical Center, 307 East 33rd St, New York, NY 10016; E-mail: [email protected] The authors report no conflicts of interest. Copyright * 2014 by Mutaz B. Habal, MD ISSN: 1049-2275 DOI: 10.1097/SCS.0000000000000628
* 2014 Mutaz B. Habal, MD
Copyright © 2014 Mutaz B. Habal, MD. Unauthorized reproduction of this article is prohibited.
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