Split cranial bone grafting in children younger than 3 years old: debunking a surgical myth

Pediatric Cranial Vault Pathology

A wide variety of diagnoses can be approached with a common framework for diagnosis, extirpation, and reconstruction of pediatric cranial vault pathologies. Durability of reconstruction is critical for the range of pediatric patients from infancy to adolescence. Rigid reconstruction, preferably with autologous tissue when possible, promotes brain protection and satisfactory aesthetic outcome. Careful planning can allow for immediate definitive reconstruction of defects without need for further surgical intervention.

Conceptual Principles in Pediatric Craniomaxillofacial Reconstruction

Pediatric craniomaxillofacial reconstruction must be approached through the lens of growth and durability. A systematic approach of matching defects to donor tissue drives the selection of autologous reconstructive technique. The menu of available methods for reconstruction can be organized in a manner similar to adults, with special considerations for growth and development. Reconstructive surgeons have the opprtunity to promote and maintain young patients' sense of identity during psychosocial development.

Pediatric Craniofacial Tumor Reconstruction

Effective management of pediatric craniofacial tumors requires coordinated input from medical, oncologic, and surgical specialties. Reconstructive algorithms must consider limitations in pediatric donor tissue and account for future growth and development. Immediate reconstruction is often focused on filling dead space, protecting underlying structures, and ensuring skeletal symmetry. Staged reconstruction occurs after the patient has reached skeletal maturity and is focused on restoring permanent dentition. Reconstructive options vary depending on the location, size, and composition of resected tissue. Virtual surgical planning (VSP) reduces the complexity of pediatric craniofacial reconstruction and ensures more predictable outcomes.

Pediatric Panfacial Fractures

Pediatric panfacial trauma is a rare occurrence with poorly understood implications for the growing child. Treatment algorithms largely mirror adult panfacial protocols with notable exceptions including augmented healing and remodeling capacities that favor nonoperative management, limited exposure to avoid disruption of osseous suture and synchondroses growth centers, and creative fracture fixation techniques in the setting of an immature craniomaxillofacial skeleton. The following article provides a review of our institutional philosophy in the management of these challenges injuries with important anatomic, epidemiologic, examination, sequencing, and postoperative considerations.

Reconstruction of a Near-total Scalp Avulsion with NovoSorb Biodegradable Temporizing Matrix: Pediatric Case Report

Traumatic dog bites of the face and head are common among the pediatric population, although injuries resulting in total or subtotal scalp avulsions are rare and life-threatening. Standard treatment in these cases includes attempts at replantation or free tissue transfer; however, these procedures may not always be possible. An alternative treatment option involves the use of dermal substitutes, such as Integra (Integra LifeScience Corporation), with subsequent skin grafting. More recently, an alternative skin substitute called NovoSorb Biodegradable Temporizing Matrix (BTM) (PolyNovo North America LLC) has displayed favorable reconstructive outcomes in recent burn literature. NovoSorb BTM is a novel, fully synthetic bilayer scaffold made of biodegradable polyurethane matrix covered with a sealing membrane. In this report, the authors describe a 3-year-old boy who presented emergently with a severe dog bite avulsion to the subpericranial level of approximately 80% of his scalp, which was not replantable. The surgical plan involved a staged reconstruction using Integra and later skin grafting. Purulent infection ensued and required removal of Integra less than 2 weeks from application. Upon clearing of the infection, the wound was successfully closed with BTM and subsequent skin grafting. With proper wound management and over 6 months of follow-up, the patient experienced excellent healing of the graft with stable calvarial coverage and an acceptable aesthetic outcome. He will undergo tissue expansion of the remaining hair-bearing scalp in the future.

Bone Flap Resorption in Pediatric Patients Following Autologous Cranioplasty

Following a decompressive craniectomy, the autologous bone flap is generally considered the reconstructive material of choice in pediatric patients. Replacement of the original bone flap takes advantage of its natural biocompatibility and the associated low risk of rejection, as well as the potential to reintegrate with the adjacent bone and subsequently grow with the patient. However, despite these advantages and unlike adult patients, the replaced calvarial bone is more likely to undergo delayed bone resorption in pediatric patients, ultimately requiring revision surgery. In this review, we describe the materials that are currently available for pediatric cranioplasty, the advantages and disadvantages of autologous calvarial replacement, the incidence and classification of bone resorption, and the clinical risk factors for bone flap resorption that have been identified to date.

Weighing In on the Controversy: Preoperative Imaging in Unicoronal Craniosynostosis Leads to Strategic Changes in Surgical Care

BACKGROUND

Clinical findings in children with unilateral coronal craniosynostosis are characteristic, and therefore clinicians have questioned the need for confirmatory imaging. Preoperative computed tomographic imaging is a powerful tool for diagnosing associated anomalies that can alter treatment management and surgical planning. The authors' aim was to determine whether and how routine preoperative imaging affected treatment management in unilateral coronal craniosynostosis patients within their institution.

METHODS

A retrospective, single-center review of all patients who underwent cranial vault remodeling for unilateral coronal craniosynostosis between 2006 and 2014 was performed. Patient data included demographics, age at computed tomographic scan, age at surgery, results of the radiographic evaluation, and modification of treatment following radiologic examination.

RESULTS

Of 194 patients diagnosed with single-suture craniosynostosis, 29 were diagnosed with unilateral coronal craniosynostosis. Additional radiographic anomalies were found in 19 unilateral coronal craniosynostosis patients (65.5 percent). These included severe deviation of the anterior superior sagittal sinus [n = 12 (41.4 percent)], Chiari I malformation [n = 1 (3.4 percent)], and benign external hydrocephalus [n = 2 (6.9 percent)]. The radiographic anomalies resulted in a change in management for 48.3 percent of patients. Specifically, alteration in frontal craniotomy design occurred in 12 patients (41.4 percent), and two patients (6.9 percent) required further radiographic studies.

CONCLUSIONS

Although clinical findings in children with unilateral coronal craniosynostosis are prototypical, preoperative computed tomographic imaging is still of great consequence and continues to play an important role in surgical management. Preoperative imaging enabled surgeons to alter surgical management and avoid inadvertent complications such as damage to a deviated superior sagittal sinus. Imaging findings of Chiari malformation and hydrocephalus also permitted judicious follow-up.

CLINICAL QUESTIONS/LEVEL OF EVIDENCE

Therapeutic, IV.

Is reverse frontal cranioplasty eligible for the correction of both the forehead deformities and the intracranial hypertension in craniosynostosis? Comparison of the preoperative and postoperative intracranial volumes

BACKGROUND

This study aimed to describe the surgical technique of reverse frontal cranioplasty (RFC), the aesthetical modification as well as the modification of intracranial volume (ICV) to assess its potential eligibility for the treatment of the intracranial hypertension (IH).

MATERIALS AND METHODS

A retrospective monocentric study included the patients with a history of craniosynostosis with a forehead deformity who underwent RFC. A subjective outcome questionnaire (SOQ) was conducted with each patient or their parent to determine their level of satisfaction after RFC. Pre- and postoperative computed tomography (CT) scans were analyzed and compared to investigate the ICV change and fronto-nasal angle.

RESULTS

Eleven patients were included in the study (6 female and 5 male) with a mean age of 10.9 years old (range 3-23 years) and an average follow-up of 4.5 years (1-11 years). All patients responded to the questionnaire with a high level of overall satisfaction (mean 9.1/10). The mean preoperative FNA was 134° ± 5° while the mean postoperative angle was 126.4° ± 6, corresponding to an average decrease of 7.6° (95% CI, 4.0-11.2°; p < 0.001). One patient with preoperative IH had a clinical recurrence during the follow-up. The ICV was significantly higher after the surgery (p < 0.0001), with an average increase of 3.2% (95% CI, 2.3-4.1%).

CONCLUSION

Reverse (RFC) is a useful technique for the correction of the frontal malformations related to craniosynostosis, such as a sloping forehead and/or a lack of the supraorbital projection. Regarding the limited gain of intracranial volume (ICV), it should not be used alone as primary cranial expansion surgery for craniosynostosis with intracranial hypertension (IH).

Autologous Calvarial Bone Remodeling Technique for Small to Medium-Sized Cranial Defects in Young Children: The "Switch-Cranioplasty" Technique

INTRODUCTION

Reconstruction of cranial defects in children less than 2 years of age, particularly when there is an associated dural defect, is challenging due to the need to accommodate active skull growth, limited options for autologous bone graft and thin calvarial bones. We use a simple remodeling technique that exploits the normal dura's inherent potential for new bone growth while covering the dural defect with adjacent skull.

CASE PRESENTATION

We describe an alternating, two-piece craniotomy or "switch-cranioplasty technique" to repair an occipital meningocele. The two pieces of craniotomy bone flap created around the existing skull and dural defect are switched in the horizontal plane in order to cover the site of the defect and the abnormal dura of the meningocele closure. The area of the original skull defect is transposed laterally over the normal dura. The healing of the lateral skull defects is facilitated with autologous bone chips and dust and covered by periosteal flaps that stimulate spontaneous re-ossification.

DISCUSSION

The advantages of this technique are the use of autologous bone adjacent to the skull defect, incorporation of the autologous bone into the growing skull, an acceptable cosmetic and functional outcome in a simple manner. The indications can be extended to include small to medium-sized calvarial defects secondary to leptomeningeal cyst and trauma.

Effect of Operative Timing and Bone Grafting on Postoperative Cephalometric Indices in Nonsyndromic Sagittal Synostosis

ABSTRACT

Surgical repair of sagittal suture craniosynostosis is highly variable, and optimal timing/use of bone grafts remains a subset of parameters that continue to be studied. We sought to compare cephalometric outcomes of early surgical intervention without bone grafting compared to later intervention with bone grafting. Patients undergoing primary surgical repair of nonsyndromic sagittal suture craniosynostosis between 2015 and 2019 were followed with preoperative measurements of cephalic index along with postoperative measurements at 6 months to 1 year, respectively. Nineteen patients undergoing cranial vault reconstruction were studied in 2 groups, namely those younger than 6 months who did not have bone grafting performed during primary repair (31.6%) and patients 6 months and older who underwent cranial vault reconstruction with bone grafting during primary repair (68.4%). Mean 6-month to 1-year postoperative cranial index was significantly increased in both groups (P < 0.001). The average cephalic index change for both groups (younger than 6 months without bone grafting, CI value change 9; 6 months and older with bone grafting; CI value change 6) was not significantly different with regards to 95% confidence interval (P = 0.30). Patients older than 6 months of age undergoing cranial vault reconstruction with bone grafting have similar cephalometric outcomes as their younger counterparts undergoing cranial vault remodeling without bone grafting. Bone grafting in the appropriate cohort may improve functional and esthetic outcomes without compromising primary surgical goals of improving cranial vault cephalometric indices.

Split Calvarial Bone Graft for Reconstruction of Skull Defect in Langerhans Cell Histiocytosis

Langerhans cell histiocytosis (LCH) is a rare disease in which histiocytes proliferates in several tissues. It mainly occurs in children between 1 and 15 years of age, and affects bone especially the skull being the most common site of invasion. It is desirable to reconstruct the skull defect after surgical removal of the lesion with autologous bone considering the fact that this disease affects children who continuously experience the deformation and growth of the frontal head. We introduce a case report who reconstructs the skull defect using split calvarial bone graft in LCH. A 3-year-old male visited the hospital with a painful, palpable protruding mass in the frontal area lasting 1 month. Craniectomy with skull tumor removal was performed by neurosurgeon, after that we harvested a calvarial bone graft and carefully separated the outer cortex from the inner cortex. Then, we covered the donor site with the inner cortex while covered the bone defect with the outer cortex and fixed with absorbable plates. The patient showed palpable mass at 1-year follow-up but it disappeared. After 5 years, there was no recurrence, the lytic lesion of the skull was resolved, and showed cosmetically good result. We conclude that the palpable lesion was more likely to be the result of postoperative swelling of the plate. We propose split calvarial bone graft as a good treatment option for reconstruction of the skull defect in LCH.

Treating nasoethmoidal encephalocele in a low-resource country: a surgical experience from a Philippine multidisciplinary craniofacial team

PURPOSE

It was described that nasoethmoidal encephalocele repair in the Philippines has been limited by insufficient resources, financial constraints, and a lack of surgical expertise. The purpose of this study was to report initial results and complications of Philippine patients with nasoethmoidal encephalocele surgically managed with an approach adapted to an environment with limited financial resources.

METHODS

All patients (n = 21) with nasoethmoidal encephalocele who underwent intracranial and extracranial repairs (frontal wedge osteotomy to access the encephalocele cyst and cranial base defect, dural defect repair, split frontal grafts fixed with polydioxanone sutures to reconstruct the cranial defect and nasal dorsum, and medial canthopexy) from January 2015 to May 2017 were included. The correlations between sizes of masses and cranial defects with the occurrence of complications were tested. The surgical results were classified based on a previously published outcome grading scales I-IV on the need for additional surgery.

RESULTS

Nineteen patients (90.5%) had unremarkable post-operative course. Two patients (9.5%) presented with complications (cerebrospinal fluid leak and surgical site infection) which were successfully managed with no additional surgery. The sizes of masses and cranial defects were not correlated (p > 0.05) with complications. The overall rate of surgical results ranked according to the need for additional surgery was 2.4 ± 0.5 (between categories II and III).

CONCLUSIONS

We reported successful surgical repair of nasoethmoidal encephaloceles in Philippine patients by a local multidisciplinary craniofacial team.

Bone Transport Distraction Osteogenesis in the Reconstruction of Pediatric Posttraumatic Calvarial Defects

Supplemental Digital Content is available in the text.

Reconstruction of posttraumatic calvarial bone defects in pediatric patients is a challenge due to the growing brain and limited autogenous bone supply. Traditional techniques such as split calvarial and particulate bone grafts are associated with prolonged operative time and significant blood loss, which is a major concern in children under the age of 3 years. Bone transport distraction osteogenesis has proven efficacy and safety in the reconstruction of other craniofacial deformities. This procedure is less invasive and requires shorter operative times and hospital stay. We report our experience with 2 cases of bone transport distraction osteogenesis for the reconstruction of large posttraumatic calvarial defects in pediatric patients.

Debunking a Surgical Myth: Do Not Touch the Temporalis

BACKGROUND

A longstanding dictum exists to avoid surgical manipulation of the temporalis muscle out of concern for an exceedingly high rate of muscle atrophy and recurrent temporal hollowing. The authors challenge this surgical myth, considering such advice to be erroneous. The authors hypothesize that elevation of the temporalis muscle, if performed using standard muscle flap principles, will demonstrate excellent results.

METHODS

To assess temporalis response to surgical manipulation, the authors reviewed patients who underwent calvarial vault remodeling by the senior author for craniosynostosis between 1988 and 2011. Nonsyndromic patients with single-suture synostosis and 5 years of follow-up were eligible for inclusion. The medical record was used to measure rates of reoperation, recurrent temporal hollowing, and persistent temporalis overcorrection.

RESULTS

Of the cohort reviewed, 196 patients met inclusion criteria. Ten patients (5.1%) exhibited recurrent bitemporal constriction. One patient (0.5%) underwent a revision temporalis turnover flap, and 2 patients (1.0%) underwent soft tissue augmentation. The overall reoperation rate was 1.5%. Temporalis overcorrection, in an attempt to prophylactically rectify the expected atrophy after temporalis manipulation, persisted in 11 patients (5.6%). Three of these patients required treatment with steroid injections, Botox injections, or operative muscle debulking. The overall reoperation rate for temporalis overcorrection was 1.5%.

CONCLUSIONS

The authors' low reoperation rates for recurrent deformity, in combination with persistent temporalis overcorrection in 5.6% of patients, should dispel the myth that manipulation of the temporalis invariably results in atrophy. The muscle may be surgically manipulated, as long as plastic surgery principles are followed.

Pediatric Cranioplasty

Historically, the approach to pediatric cranioplasty has been largely extrapolated from the treatment of adults. More recently, however, the intricacies of pediatric cranial reconstruction have become better understood, and the surgical management has been refined contemporaneously. Each patient's cranial defect bears a unique set of challenges and, as such, the choice of cranioplasty technique must be tailored accordingly.

An Outcomes Comparison Between Autologous and Alloplastic Cranioplasty in the Pediatric Population

BACKGROUND

The use of alloplastic material in cranial reconstruction has been well described in the adult population, especially when a paucity of autologous tissue exists. In children it is unknown how long-term growth, however, may be affected by the implantation of nonexpansible alloplastic material. Therefore, the authors sought to compare the outcomes of pediatric patients undergoing alloplastic versus autologous cranial reconstruction.

METHODS

To assess the safety and long-term outcomes of alloplastic cranioplasty in children, an institutional review board-approved, retrospective, single institution review of pediatric patients undergoing cranioplasty was performed from 2000 to 2014. The age at surgery, cause of the cranial defect, defect size, time since initial surgery to reconstruction, implant type, and complications were assessed. Postreconstruction imaging was reviewed if available.

RESULTS

A reconstructive cranioplasty was performed in 41 pediatric patients (ages 1-19 years, average 7.35 years). Thirty patients underwent alloplastic reconstruction (age 4.37 ± 5.57 years), and 11 underwent autologous reconstruction (age 2.00 ± 3.74 years). The size of the cranial defects was 144.01 ± 393.04 cm for autologous and 405.31 ± 572.96 cm for alloplastic reconstructions. Follow-up for all patients was an average of 2.33 ± 2.76 years (0.1-9 years). No patients in either group showed evidence of elevated intracranial pressure after cranioplasty. In long-term follow-up, none of the implants were exposed or lost because of infection. Computed tomography and physical examination demonstrated that there was no skull growth restriction in either group.

CONCLUSIONS

Our data show that alloplastic cranioplasty in the pediatric population is a safe alternative, when autologous cranial bone is not available.

Customized acrylic implants for reconstruction of extensive skull defects: an exception approach for selected patients

ABSTRACT Objective: to present our experience in the surgical treatment of extensive skullcap defects with customized acrylic implants. Methods: we conducted a retrospective analysis of patients with extensive skull defects undergoing acrylic cranioplasties between 2004 and 2013. We carefully selected all patients and classified surgical results based on three scales (craniofacial esthetics, improvement of facial symmetry and need for additional surgery). Results: fifteen patients underwent cranioplasty with intraoperative acrylic implants, whether manually customized (46.67%) or made with prototyped three-dimensional biomodels (53.33%). There were two (13.33%) complications (one infection with implant withdrawal and one seroma). We considered the craniofacial aesthetics excellent (50%), the degree of improvement of craniofacial symmetry satisfactory (57.14%), and the overall mean of surgical results according to the need for new surgeries was 1.5±0.52. Conclusion: cranioplasties of patients with extensive skullcap defects should obey careful and predetermined criteria, both for selection and for the acrylic implant customization method.

Micro-CT Analysis of Bone Healing in Rabbit Calvarial Critical-Sized Defects with Solid Bioactive Glass, Tricalcium Phosphate Granules or Autogenous Bone

Objectives

The purpose of the present study was to evaluate bone healing in rabbit critical-sized calvarial defects using two different synthetic scaffold materials, solid biodegradable bioactive glass and tricalcium phosphate granules alongside solid and particulated autogenous bone grafts.

Material and Methods

Bilateral full thickness critical-sized calvarial defects were created in 15 New Zealand white adult male rabbits. Ten defects were filled with solid scaffolds made of bioactive glass or with porous tricalcium phosphate granules. The healing of the biomaterial-filled defects was compared at the 6 week time point to the healing of autologous bone grafted defects filled with a solid cranial bone block in 5 defects and with particulated bone combined with fibrin glue in 10 defects. In 5 animals one defect was left unfilled as a negative control. Micro-computed tomography (micro-CT) was used to analyze healing of the defects.

Results

Micro-CT analysis revealed that defects filled with tricalcium phosphate granules showed new bone formation in the order of 3.89 (SD 1.17)% whereas defects treated with solid bioactive glass scaffolds showed 0.21 (SD 0.16)%, new bone formation. In the empty negative control defects there was an average new bone formation of 21.8 (SD 23.7)%.

Conclusions

According to findings in this study, tricalcium phosphate granules have osteogenic potential superior to bioactive glass, though both particulated bone with fibrin glue and solid bone block were superior defect filling materials.

A Novel Local Autologous Bone Graft Donor Site After Scalp Tissue Expansion in Aplasia Cutis Congenita

Aplasia cutis congenita (ACC) is a rare condition often presenting as an absent area of cutaneous scalp. The calvarium and dura may also be affected. Scalp reconstruction with tissue expansion is often needed for large defects. Patients involving deficient calvarial bone present a dilemma for the reconstructive surgeon, because bone graft donor sites are limited in young children.A thick, bony rim has been noted to form around the periphery of scalp tissue expanders. The authors present a series of 3 patients with ACC for whom this bony hyperostosis was used as donor particulate bone graft at the time of scalp tissue expansion. There was 85 to 100% graft ossification on postoperative computed tomography scan. There were no bone graft-related complications.In conclusion, the hyperostotic rim that forms after scalp tissue expansion can be successfully used as particulate bone graft, decreasing the number of procedures needed for patient with ACC and obviating the need for other donor sites.

Split Rib Cranioplasty for Frontal Osteoma: A Case Report and Review of the Literature

INTRODUCTION

Osteomas are benign bone tumors. They generally lead to a local thickness on the frontal bone in calvarium. When they occur on the forehead, they often cause a cosmetic disorder without any neurological symptoms. The significant problem is the repair method of the cranium defect.

CASE PRESENTATION

The rib of a 34-year-old female was split and used for a small cranium defect of 3 × 3.5 cm. The preferred method and the obtained results were presented under the guidance of the literature.

CONCLUSIONS

Along with the technological advancement, different materials are employed according to the size of the cranium defect and the age of the case. The application of split costa cranioplasty for the small cranium defects in the region of patient's face is the method with the least possibility of complications, and its cosmetic and functional results are quite promising.

The Recent Revolution in the Design and Manufacture of Cranial Implants: Modern Advancements and Future Directions

Large format (i.e., >25 cm) cranioplasty is a challenging procedure not only from a cosmesis standpoint, but also in terms of ensuring that the patient's brain will be well-protected from direct trauma. Until recently, when a patient's own cranial flap was unavailable, these goals were unattainable. Recent advances in implant computer-aided design and 3-dimensional (3-D) printing are leveraging other advances in regenerative medicine. It is now possible to 3-D-print patient-specific implants from a variety of polymer, ceramic, or metal components. A skull template may be used to design the external shape of an implant that will become well integrated in the skull, while also providing beneficial distribution of mechanical force in the event of trauma. Furthermore, an internal pore geometry can be utilized to facilitate the seeding of banked allograft cells. Implants may be cultured in a bioreactor along with recombinant growth factors to produce implants coated with bone progenitor cells and extracellular matrix that appear to the body as a graft, albeit a tissue-engineered graft. The growth factors would be left behind in the bioreactor and the graft would resorb as new host bone invades the space and is remodeled into strong bone. As we describe in this review, such advancements will lead to optimal replacement of cranial defects that are both patient-specific and regenerative.

Armadillo cranioplasty for expansion and remodeling in craniosynostosis

Craniosynostosis is typically treated in the first year of life, when osteogenic potential is high and residual obligate skull defects heal. Delayed reconstruction can result in persistent skull defects because of diminished osteogenic potential. Adequately expanding the cranium yet minimizing residual skull defects in older patients presents a conundrum. Although secondary cranioplasty can be performed, primary cortical bone coverage is preferred. The authors present a technique of cranial expansion by sliding stairstep osteotomies, thus preventing residual skull defects when treating craniosynostosis at an advanced age.

CLINICAL QUESTION/LEVEL OF EVIDENCE

Therapeutic, IV.

Cranioplasty for large-sized calvarial defects in the pediatric population: a review

Large-sized calvarial defects in pediatric patients pose a reconstructive challenge because of children's unique physiology, developing anatomy, and dynamic growth. We review the current literature and outcomes with autologous and alloplastic cranioplasty in the pediatric population.