Technical evolution of pediatric neurosurgery: craniosynostosis from 1972 to 2023 and beyond.

Very few clinical entities have undergone so many different treatment approaches over such a short period of time as craniosynostosis. Surgical treatments for this condition have ranged from simple linear craniectomies, accounting for the specific role of cranial sutures in assuring the normal growth of the skull, to more complex cranial vault reconstructions, based on the perceived role of the skull base in affecting the growth of the skull. While a great deal of evolution has occurred, there remains controversy regarding the ideal treatment including the best surgical technique, the optimal age for surgery, and the long-term morphological and neurodevelopmental outcomes. The evolution of the surgical management of craniosynostosis in the last 50 years has been affected by several factors. This includes the awareness of needing to operate on affected children during infancy to achieve the best results, the use of multistage operations, the availability of more sophisticated surgical tools, and improved perioperative care. In some forms of craniosynostosis, the operations can be carried out at a very young age with low morbidity, and with the postoperative use of a molding helmet, springs, or distractors, these operations prove to be as effective as traditional larger cranial reconstructions performed in older children. As a consequence, complex surgical operations have become progressively less utilized. A second relevant advance was the more recent advent of a molecular diagnosis, which allowed us to understand the pathogenesis of some associated malformations and neurodevelopmental issues that were observed in some children despite appropriate surgical treatment. Future research should focus on improving the analysis of longer-term outcomes and understanding the natural history of craniofacial conditions, including what issues persist despite optimal surgical correction. Progress in molecular investigations concerning the normal and pathological development of cranial sutures could be a further significant step in the management of craniosynostosis, possibly favoring a "medical" treatment in the near future. Artificial intelligence will likely have a role in establishing the diagnosis with less reliance on radiographic studies and in assisting with surgical planning. Overall, much progress has been made, but there remains much to do.

In situ bone regeneration of large cranial defects using synthetic ceramic implants with a tailored composition and design.

The repair of large cranial defects with bone is a major clinical challenge that necessitates novel materials and engineering solutions. Three-dimensionally (3D) printed bioceramic (BioCer) implants consisting of additively manufactured titanium frames enveloped with CaP BioCer or titanium control implants with similar designs were implanted in the ovine skull and at s.c. sites and retrieved after 12 and 3 mo, respectively. Samples were collected for morphological, ultrastructural, and compositional analyses using histology, electron microscopy, and Raman spectroscopy. Here, we show that BioCer implants provide osteoinductive and microarchitectural cues that promote in situ bone regeneration at locations distant from existing host bone, whereas bone regeneration with inert titanium implants was confined to ingrowth from the defect boundaries. The BioCer implant promoted bone regeneration at nonosseous sites, and bone bonding to the implant was demonstrated at the ultrastructural level. BioCer transformed to carbonated apatite in vivo, and the regenerated bone displayed a molecular composition indistinguishable from that of native bone. Proof-of-principle that this approach may represent a shift from mere reconstruction to in situ regeneration was provided by a retrieved human specimen, showing that the BioCer was transformed into well-vascularized osteonal bone, with a morphology, ultrastructure, and composition similar to those of native human skull bone.

Prevalence of Postoperative Complications of Autologous and Heterologous Cranioplasty in the Pediatric Population: A Systematic Review of the Literature.

INTRODUCTION: Cranial reconstruction (CR) is a neurosurgical procedure performed to restore the cranial vault after a decompressive craniectomy. There are contrasting reports from the literature about the complications related to the use of heterologous materials for CR in the pediatric population. In this study, the authors try to better define such a rate of adverse events for autologous and heterologous materials. MATERIALS AND METHODS: A systematic review of articles published up to December 2021 was performed. Studies were included if they reported the specific use of cranioplasty materials following craniectomy in patients younger than 18 years of age and had a minimum follow-up of at least 1 year. RESULTS: A total of 20 studies were selected. A total of 544 cases were included, of which 422 (77.6%) were with heterologous materials and 122 (22.4%) with autologous bone. The mean average age was 9.5 years. Polyetheretherketone and polymethylmethacrylate reported 29% and 33.3%, respectively, of complications, but only 3% and 5.6% of surgical revision. PHA reported a rate of 11.9%. Titanium reported 9.2% of complications and 4.1% of surgical revisions. Porous polyethylene had a complication rate of 36.4% and a revision rate of 0%. CONCLUSION: There is still no perfect material for CR. It seems that heterologous materials are superior to autologous bone for CR in children, and we may consider, whenever economic conditions will allow it, to use alloplastic material as first-line in small children.

From Reparative Surgery to Regenerative Surgery: State of the Art of Porous Hydroxyapatite in Cranioplasty.

Decompressive craniectomy is one of the most common neurosurgical procedures, usually performed after neuropathological disorders, such as traumatic brain injury (TBI), but also vascular accidents (strokes), erosive tumours, infections and other congenital abnormalities. This procedure is usually followed by the reconstruction of the cranial vault, which is also known as cranioplasty (CP). The gold-standard material for the reconstruction process is the autologous bone of the patient. However, this is not always a feasible option for all patients. Several heterologous materials have been created in the last decades to overcome such limitation. One of the most prominent materials that started to be used in CP is porous hydroxyapatite. PHA is a bioceramic material from the calcium phosphate family. It is already widely used in other medical specialties and only recently in neurosurgery. In this narrative review of the literature, we summarize the evidence on the use of PHA for cranial reconstruction, highlighting the clinical properties and limitations. We also explain how this material contributed to changing the concept of cranial reconstruction from reparative to regenerative surgery.

From decompressive craniectomy to cranioplasty and beyond-a pediatric neurosurgery perspective.

PURPOSE: Decompressive craniectomy (DC) is an established neurosurgical emergency technique. Patient selection, optimal timing, and technical aspects related to DC and subsequent cranioplasty remain subjects of debate. For children, the overall degree of evidence is low, compared with randomized controlled trials (RCTs) in adults. METHODS: Here, we present a detailed retrospective analysis of pediatric DC, covering the primary procedure and cranioplasty. Results are analyzed and discussed in the light of modern scientific evidence, and conclusions are drawn to stimulate future research. RESULTS: The main indication for DC in children is traumatic brain injury (TBI). Primary and secondary DC is performed with similar frequency. Outcome appears to be better than that in adults, although long-term complications (especially bone flap resorption after autologous cranioplasty) are more common in children. Overt clinical signs of cerebral herniation prior to DC are predictors of poor outcome. CONCLUSIONS: We conclude that DC is an important option in the armamentarium to treat life-threatening intracranial hypertension, but further research is warranted, preferentially in a multicenter prospective registry.

Cranioplasties following craniectomies in children-a multicenter, retrospective cohort study.

OBJECTIVE: Complications following pediatric cranioplasty after craniectomy with either autologous bone flaps or cranial implants are reported to be common, particularly bone flap resorption. However, only sparse data are available regarding cranioplasty strategies, complications, and outcomes. This manuscript describes a Canadian-Dutch multicenter pediatric cohort study with autografts and cranial implant cranioplasties following craniectomies for a variety of indications. METHODS: The study included all children (< 18 years) who underwent craniectomy and subsequent cranioplasty surgeries from 2008 to 2014 (with a minimum of 1-year follow-up) at four academic hospitals with a dedicated pediatric neurosurgical service. Data were collected regarding initial diagnosis, age, time interval between craniectomy and cranioplasty, bone flap storage method, type of cranioplasty for initial procedure (and redo if applicable), and the postoperative outcome including surgical site infection, wound breakdowns, bone flap resorption, and inadequate fit/disfigurement. RESULTS: Sixty-four patients (46 males, average age 9.7 ± 5.5 years) were eligible for inclusion, with mean follow-up of 82.3 ± 31.2 months after craniectomy. Forty cranioplasties (62.5%) used autologous bone re-implant, 23 (57.5%) of which showed resorption. On average, resorption was documented at 434 days (range 62-2796 days) after reimplantation. In 20 cases, a revision cranioplasty was needed. In 24 of the post-craniectomy cases (37.5%), a cranial implant was used with one of ten different implant types. Implant loosening prompted a complete revision cranioplasty in 2 cases (8.3%). Cranial implants were associated with low morbidity and lower reoperation dates compared to the autologous cranioplasties. CONCLUSION: The most prominent finding in this multicenter cohort study was that bone flap resorption in children remains a common and widespread problem following craniectomy. Cranioplasty strategies varied between centers and evolved over time within centers. Cranial implants were associated with low morbidity and low reoperation rates. Still, longer term and prospective multicenter cohort studies are needed to optimize cranioplasty strategies in children after craniectomies.

One-stage frame-guided resection and reconstruction with PEEK custom-made prostheses for predominantly intraosseous meningiomas: technical notes and a case series.

Treatment of intraosseous meningiomas is a two-staged procedure including tumor resection and cranial reconstruction. Several are the potential pitfall of this kind of surgery such as the conspicuous dimensions usually reached by the tumor and the peculiar involvement of irregular and deep bony structures. For these reasons, a surgical accurate virtual planning and a careful removal followed by tailored reconstruction are mandatory to achieve satisfactory results. We analyzed six patients operated on for intraosseous meningiomas between September 2014 and June 2018. Resection strategy was planned beforehand and shared with the manufacturer who provided the PEEK cranioplasty used in the reconstructive phase. Between September 2014 and April 2018, six patients affected by intraosseous meningioma were operated on. Female/male ratio was 5:1 and mean age was 54 ± 10.8 years. Mean FU was 20.3 ± 16.4 months. Mean dimension was 73.9 ± 24.8 mm × 69.2 ± 16.2 mm. Mean surgical time was 5.1 ± 1.1 h. The resection of intraosseous meningiomas requires the earliest and finest reconstructive phase. Custom-made implants should be considered the gold-standard for cranioplasty, especially in large skull and in frontal or hairless areas of the skull. The described technique is simple, accurate, and effective in achieving good results in disease control as well as cosmetic and functional restoration.

A case series of early and late cranioplasty-comparison of surgical outcomes.

BACKGROUND: Cranioplasty is an increasingly common procedure performed in neurosurgical centres following a decompressive craniectomy (DC), however, timing of the procedure varies greatly. OBJECTIVES: The aim of this study is to compare the surgical outcomes of an early compared to a late cranioplasty procedure. METHODS: Ninety adult patients who underwent a prosthetic cranioplasty between 2014 and 2017 were studied retrospectively. Timing of operation, perioperative complications and length of stay were assessed. Early and late cranioplasties were defined as less or more than 3 months since craniectomy respectively. RESULTS: Of the 90 patients, 73% received a late cranioplasty and 27% received an early cranioplasty. The median interval between craniectomy and cranioplasty was 13 months [range 3-84] in late group versus 54 days [range 33-90] in early group. Twenty-two patients in the early group (91%) received a cranioplasty during the original admission while undergoing rehabilitation. Complications were seen in 25 patients (28%). These included wound or cranioplasty infection, hydrocephalus, symptomatic pneumocephalus, post-operative haematoma and cosmetic issues. The complication rate was 21% in the early group and 30% in the late group (P value 0.46). There was no significant difference in the rate of infection or hydrocephalus between the two groups. Length of stay was not significantly increased in patients who received an early cranioplasty during their initial admission (median length of stay 77 days versus 63 days, P value 0.28). CONCLUSION: We have demonstrated the potential for early cranioplasty to be a safe and viable option, when compared to delayed cranioplasty.

Bilateral Transverse Sinus Thrombosis following Craniotomy and Cranial Reconstruction for Sagittal Craniosynostosis.

INTRODUCTION: Craniotomy and cranial reconstruction is the most common procedure for children older than 6 months with craniosynostosis. Dural sinus thrombosis after this surgery has not been well reported in the literature. CASE PRESENTATION: This 2-year-old child underwent a bilateral craniotomy and cranial reconstruction for sagittal craniosynostosis. He had a partial thickness tear of the wall of the right transverse sinus which was uneventfully managed. Postoperative imaging showed evidence of bilateral thrombosis of the transverse sinus with a small occipital hemorrhage. He was started on low-molecular-weight heparin. Follow-up imaging showed nonprogression of the thrombosis. Four days later, he developed pulmonary hemorrhage, had an extended period of low oxygenation and hypotension with acute respiratory distress syndrome, and had to be ventilated for a prolonged period. Follow-up MRI showed evidence of extensive bilateral cortical hypointensities possibly due to hypoxemia. At the last follow-up, he continued to be grossly neurologically impaired. CONCLUSION: Thrombosis of the dural sinuses is a very rare occurrence after an extensive craniotomy and cranial reconstruction. However, it should be considered during the postoperative period and, if diagnosed, it should be treated with anticoagulants. Avoiding a direct sinus injury during reflection of the craniotomy flap and covering the exposed sinus with moist cottonoids during the surgery is advocated to prevent sinus thrombosis.

Technical note: virtual reconstruction of KNM-ER 1813 Homo habilis cranium.

A very limiting factor for paleoanthropological studies is the poor state of preservation of the human fossil record, where fragmentation and deformation are considered normal. Although anatomical information can still be gathered from a distorted fossil, such specimens must typically be excluded from advanced morphological and morphometric analyses, thus reducing the fossil sample size and, ultimately, our knowledge of human evolution. In this contribution we provide the first digital reconstruction of the KNM-ER 1813 Homo habilis cranium. Based on state of-the-art three-dimensional digital modeling and geometric morphometric (GM) methods, the facial portion was aligned to the neurocranium, the overall distortion was removed, and the missing regions were restored. The reconstructed KNM-ER 1813 allows for an adjustment of the anthropometric measurements gathered on the original fossil. It is suitable for further quantitative studies, such as GM analyses focused on skull morphology or for finite element analysis to explore the mechanics of early Homo feeding behavior and diet.

Bone graft absorption complication following cranioplasty: A retrospective institutional study.

The aim of the present retrospective study was to confer the factors that are related to bone graft absorption and affect the outcomes of patients following cranioplasty (CPL). The present retrospective study includes cases of patients that underwent CPL between February, 2013 and December, 2022. All participants had a follow-up period of 1 to 10 years from the day of discharge from the hospital. In total, 116 (62.3%) of the 186 patients that underwent decompressive craniectomy (DC) were enrolled in the present study for CPL. A total of 109 (93.9%) patients were included in group A, and 7 (6.0%) patients were included in group B. On the whole, the results of the present study suggest that a CPL after 2.5-7.7 months of DC increases the possibility of bone absorption.

Flap Design for Cranial Reconstruction: An Analysis of Craniectomy and Cranioplasty Incisions.

Background: The surgical approach for cranial reconstruction is influenced by the presence of pre-existing scar tissue. Scars that lie within the vicinity of cranial defect require modification. Purpose: The present study was conducted to analyse co-relation between craniectomy scar and cranioplasty incision. Materials and Methods: A retrospective evaluation of 70 patients who were divided into three groups based on location of cranioplasty incision line was done. In group I, incision was located parallel and outside the scar; group II, incision was located over the scar; and group III, mixed and criss-cross incision was present. The primary outcome variable of interest was to analyse co-relation between craniectomy and cranioplasty incisions. Results: There were 45 cases of group I, 15 cases of group II and 10 cases of group III. Thirty-three patients had defect on left side, 26 had on right side, and 10 had bifrontal defect. No significant association was noted between the site and cranioplasty incision (Chi2 = 9.155, p = 0.433 and likelihood ratio = 9.487, p = 0.394). Conclusion: Well-vascularized broad-based scalp flap that provides adequate exposure and located on healthy bone irrespective of pre-existing craniectomy scar forms the mainstay of successful cranial reconstruction.

Revolutionizing Neurosurgery: The Cutting-Edge Era of Digitally Fabricated Cranial Stents.

Cranial defects are broadly classified as either congenital or acquired. The prevalence of cranial injuries has notably increased, propelled by a heightened emphasis on aesthetics and the demand for skull reconstruction in contemporary society. Consequently, rehabilitation for these defects has also surged. Surgical correction or repair, known as cranioplasty, not only aims at aesthetic rehabilitation but also addresses psychological issues, improving social acceptance and overall performance. Amid evolving trends, the availability of advanced biomedical tools, technologies, and materials empowers surgeons and prosthodontists, leading to improved outcomes in aesthetics and functionality. One noteworthy technique highlighted in this case report involves using bone cement in conjunction with polymethyl methacrylate, adding novelty to the approach. The interdisciplinary management team, consisting of prosthodontists and neurosurgeons, played a pivotal role in improving neurological status and cosmetic outcomes for the patients.

Postmortem or Perimortem Injury? Presentation of an incredible court case in which flames are the protagonists of a murder.

Background: Establishing the cause of death when analysing burnt human remains is limiting due to thermal degradation. The heat generated by high combustion degrades the bone structure, definitively hiding the perimortem trauma in most cases, which is crucial for solving a court case. Case report: In November 2019, a completely burnt corpse was found inside a car set on fire near a location in Reggio Calabria, Italy. The corpse was subsequently subjected to an initial radiodiagnostic examination and an anthropological/medico-legal investigation, in order to confirm the biological profile of the unidentified subject, define the cause of death and assess the presence of perimortal lesions through macroscopic analysis of skull fragments subjected to fleshing. Conclusions: The soft tissue fleshing of the burnt skull fragments allowed the reconstruction of a partial calotte. Macroscopic analysis of the consolidated shell identified in the left fronto-parietal region a clear linear fracture, perimortal in nature, compatible with blunt trauma. Autopsy examination revealed the presence of carbonaceous residues within the larynx and especially the trachea, confirming ante-mortem combustion.The results of the autopsy examination and the anthropological analysis allowed us to state that the net linear fracture, perimortal in nature, caused the subject a complex encephalic trauma, resulting in loss of consciousness and subsequent death due to carbon monoxide inhalation. This result not only confirms the malicious hypothesis, but reveals a deliberate burning of the victim in order to conceal the evidence necessary to solve the forensic case.

A Novel Method of Frontal Bone Reconstruction Using Patient-Specific Implants and Costochondral Grafts: A Case Report.

The frontal bone is the vital component of the human skull and forms a part of the anterior skull vault, base, and roof of the orbits. Frontal bone defects may arise secondary to various causes like trauma, congenital defects including craniofacial clefts, tumors in the frontal bone requiring surgical intervention, and infections, like osteomyelitis, that cause osteonecrosis of the frontal bone. Reconstruction of frontal bone has been explored in the literature, and various materials are available for rehabilitation, like auto/allografts, and alloplastic materials, including bone cement, titanium meshes, and patient-specific implant (PSI). All the available materials have their own advantages and disadvantages; hence, depending on the anatomy and physiology of the frontal bone and the involvement of the naso-orbito-ethmoidal (NOE) complex, patient selection and treatment plan become very crucial. This report presents a case of the frontal bone with a NOE defect, secondary to trauma, reconstructed using a PSI and costochondral graft.

Outcomes of Cranioplasty Reconstructions: Review of Cranioplasty Implants and Free Flap Coverage Variables that Affect Implant Exposure.

BACKGROUND: Complex scalp wounds with cranial/dural involvement are challenging to reconstruct. Successful reconstruction can be achieved with cranial implants/hardware and free flap coverage. Wounds can breakdown and require revision procedures. We addressed reconstructive outcomes of different implants requiring free flaps. OBJECTIVE: To determine the factors associated with implant exposure. DESIGN: Multi-institutional retrospective review of 82 patients, 2000-2020, repaired with cranial implants and free flap coverage. RESULTS: Implant exposure occurred in 13/82 (16%) reconstructions. Flap atrophy or thinning leading to implant exposure occurred in 11/82 (13%) reconstructions, including partial flap atrophy OR 0.05 (95% CI 0.0-0.35) and total flap atrophy OR 0.34 (95% CI 0.02-19.66). Revision surgeries that occurred subsequent to flap reconstruction were also associated with implant exposure (OR 0.02 (95% CI 0.0-0.19)). Implant exposure was not associated with radiation therapy, patient health history, implant type, flap type, or postoperative complications. CONCLUSIONS: Implant exposure is associated with free flap atrophy, leading to inadequate implant coverage and the need for revision surgeries. Completing reconstruction with adequate soft tissue bulk and coverage and avoiding revision surgery may decrease the risk for implant exposure over time. LEVEL OF EVIDENCE: 4 Laryngoscope, 133:2954-2958, 2023.

Cranioplasty With a Customized Polymethylmethacrylate Implant Using a 3D Printer.

The occurrence of cranial injuries has increased dramatically, and due to greater awareness among the people concerned with aesthetics needing skull reconstruction, rehabilitation of these defects has also increased in our modern age. Rehabilitation of these deficiencies with prostheses not only works as a protective shell but also improves the patient's neurological state. These cranial deformities necessitate surgical correction or repair, known as cranioplasty. Its goal is not only to rehabilitate the imperfection aesthetically, but also to alleviate psychological issues and improve the patient's social acceptance and performance. New biomedical tools, technologies, and materials are available to surgeons and prosthodontists to improve aesthetics and functions. The purpose is to develop a novel method involving affordable 3D printing technology for creating individualized polymethylmethacrylate (PMMA) implants, aiming to democratize technology in prosthodontics.

A unique presentation of Crouzon-like syndrome: Complex craniosynostosis in the absence of genetic mutations or familial predisposition - A case report.

Background: Crouzon syndrome is a rare genetic disorder characterized by premature fusion of skull sutures during skull development, resulting in various craniofacial abnormalities and complex craniosynostosis is a condition in which more than one such sutures of the skull fuse prematurely. Case Description: Herein, we present a case of a 5-year-old male diagnosed with Crouzon-like syndrome and complex craniosynostosis involving multiple cranial sutures, including metopic, sagittal, coronal (right and left), and lambdoid sutures, and without any identifiable mutations on karyotyping. The patient underwent successful surgical intervention with a satisfactory outcome, highlighting the importance of early diagnosis and intervention to prevent or minimize associated neurological manifestations and craniofacial abnormalities. Conclusion: Our case report underscores the involvement of multiple cranial sutures in complex craniosynostosis and the absence of identifiable mutations or family history of similar craniofacial abnormalities, providing important insights into the diagnosis and management of this condition.

Design of customized implants and 3D printing of symmetric and asymmetric cranial cavities.

A methodology has been developed in this work to design customized cranial implants from computed tomography (CT) scan images for symmetric as well as asymmetric defects. The two-dimensional CT scan images were converted into three-dimensional geometric models using software packages. Two cases of cranial cavities at different locations were considered for implant design using two different approaches. Case 1 is having a symmetric cranial cavity while Case 2 has an asymmetric frontal cranial cavity. The craniums with defects were 3D reconstructed. Customized cranial implants were made for the two cases. In Case 1, symmetry was used to design the cranial implant. Symmetry cannot be used in Case 2. In Case 2, the implant was designed by blending from the surface available adjacent to the missing portion of the cranium. 3D reconstructed bone models and customized implants were 3D printed in poly-lactic acid (PLA) using a fused deposition modeling process for form and fit evaluation. Finite element analysis was performed to compare the mechanical behavior of bone, and the two biomaterials - polyether ether ketone (PEEK), and Ti6Al4V. Static structural finite element analysis was performed to simulate the impact of falling off a bicycle with an impact on the cranial implants in the two cases. The load was modeled as a normal force acting on the surface of the implant. It was found that the stresses in the titanium alloy are comparable to those of PEEK for both the cases. However, the strains and deformation were found to be much smaller compared to those in PEEK. Therefore, the titanium alloy is the material of choice for both the cases among the materials under consideration. The designed implants are solid hence may face the challenge in bone ingrowth. In future studies, the implant can be made porous by incorporating a lattice structure to enhance osseointegration and promote bone ingrowth. Implants for both symmetric and asymmetric defect cases in cranium were successfully designed.

Digital Reconstructions Using Linear Regression: How Well Can It Estimate Missing Shape Data from Small Damaged Areas?

Skeletal remains analyzed by anthropologists, paleontologists and forensic scientists are usually found fragmented or incomplete. Accurate estimations of the original morphologies are a challenge for which several digital reconstruction methods have been proposed. In this study, the accuracy of reconstructing bones based on multiple linear regression (RM) was tested. A total of 150 digital models from complete zygomatics from recent past populations (European and African American) were studied using high-density geometric morphometrics. Some landmarks (i.e., 2, 3 and 6) were coded as missing to simulate incomplete zygomatics and the missing landmarks were estimated with RM. In the zygomatics, this simulated damage affects a few square centimeters or less. Finally, the predicted and original shape data were compared. The results indicate that the predicted landmark coordinates were significantly different from the original ones, although this difference was less than the difference between the original zygomatic and the mean zygomatic in the sample. The performance of the method was affected by the location and the number of missing landmarks, with decreasing accuracy with increasing damaged area. We conclude that RM can accurately estimate the original appearance of the zygomatics when the damage is small.