Synchronized "One-Step" Resection and Cranio-Orbital Reconstruction for Spheno-Orbital Lesions With Custom Made Implant

3D Printing for Customized Bone Reconstruction in Spheno-Orbital Meningiomas: A Systematic Literature Review and Institutional Experience

Background: The treatment of spheno-orbital meningiomas (SOMs) requires extensive bone resections, creating significant defects in a complex geometrical space. Bone reconstruction represents a fundamental step that optimizes long-term aesthetic and functional outcomes. In recent years, 3D printing technology has also been exploited for complex skull base reconstructions, but reports remain scarce. Methods: We retrospectively analyzed four consecutive patients who underwent SOM resection and one-step 3D PEEK customized reconstruction from 2019 to 2023. A systematic review of 3D printing customized implants for SOM was then performed. Results: All patients underwent a frontotemporal craniotomy, removal of SOM, and reconstruction of the superolateral orbital wall and pterional region. The aesthetic outcome was extremely satisfactory in all cases. No orbital implant malposition or infectious complications were documented. Eleven papers were included in the literature review, describing 27 patients. Most (23) patients underwent a single-stage reconstruction; in three cases, the implant was positioned to correct postoperative delayed enophthalmos. Porous titanium was the most used material (16 patients), while PEEK was used in three cases. Prosthesis malposition was described in two (7.4%) patients. Conclusions: Single-step reconstruction with a personalized 3D PEEK prosthesis represents a valid reconstruction technique for the treatment of SOMs with good aesthetic outcomes.

Endoscopic transorbital and transcranial multiportal resection of a sphenoorbital meningiomas with custom bone 3D printing reconstruction: Case report

BACKGROUND

Sphenoorbital meningiomas (SOM) harbor intrinsic features that render their surgical management and the reconstruction of the resulting bony defect overtly challenging.

METHODS

A 70-year-old woman, harboring a long-standing left frontotemporal bony swelling conservatively managed, presented with progressive left proptosis. Radiological features were consistent with an en plaque SOM. A one-step multiportal transcranial and endoscopic transorbital approach (TOA) with custom bone three-dimensional (3D) printing reconstruction using polymethylmethacrylate (PMMA) was scheduled.

RESULTS

Postoperative functional and aesthetic results were excellent, with proptosis and calvarian deformity resolution. Tumor subtotal resection was achieved. Histopathological diagnosis confirmed a transitional meningioma (WHO grade I).

CONCLUSIONS

The endoscopic TOA, isolated or as part of a multiportal strategy, has entered the surgical armamentarium for the treatment of SOMs. A customized PMMA cranioplasty can be considered a possible option for the reconstruction of large bony defects in a one-step fashion.

Single-step resection and reconstruction of orbito-fronto-temporal pathologies using a PMMA CAD-implant

BACKGROUND

Resection of bone infiltrating meningiomas of the sphenoid plane and the orbital walls is a highly challenging neurosurgical procedure. In this study, the authors present 11 cases of fronto-orbital and sphenoid wing meningioma which were subjected to tumor resection and cranioplasty using a pre-designed CAD PMMA-implant in one single staged procedure.

METHODS

Eleven cases were prospectively analyzed from January 2011 to December 2018. In all cases preoperative CT scans were performed and evaluated, in order to produce a customized PMMA-implant, fitting the osseous defect left after surgical resection of the predefined tumorous mass. Surgery was performed with standard techniques with the addition of availability of preplanned neuronavigational data as well as a matching template of the implant for intraoperative use. After tumor resection, cranioplasty followed using the predesigned PMMA implant.

RESULTS

Gross total resection was achieved in 82% (9 of 11 cases). Mean time of surgery for the combined procedure resulted in 223min±99min, with a mean blood loss of 427±192cc. Mean hospital stay for the combined procedure resulted in 11.5±3 days. In 18% of the cases (2/11), patients suffered from late onset infection of the implant and needed a surgical removal.

CONCLUSIONS

The presented data show that gross total resection and subsequent single staged bone reconstruction in osseous sphenoid wing and orbital rim meningiomas can be achieved using predesigned PMMA CAD implants with preplanned tumor resection borders with neuronavigational guidance.

Augmented reality-assisted craniofacial reconstruction in skull base lesions - an innovative technique for single-step resection and cranioplasty in neurosurgery

Defects of the cranial vault often require cosmetic reconstruction with patient-specific implants, particularly in cases of craniofacial involvement. However, fabrication takes time and is expensive; therefore, efforts must be made to develop more rapidly available and more cost-effective alternatives. The current study investigated the feasibility of an augmented reality (AR)-assisted single-step procedure for repairing bony defects involving the facial skeleton and the skull base. In an experimental setting, nine neurosurgeons fabricated AR-assisted and conventionally shaped ("freehand") implants from polymethylmethacrylate (PMMA) on a skull model with a craniofacial bony defect. Deviations of the surface profile in comparison with the original model were quantified by means of volumetry, and the cosmetic results were evaluated using a multicomponent scoring system, each by two blinded neurosurgeons. Handling the AR equipment proved to be quite comfortable. The median volume deviating from the surface profile of the original model was low in the AR-assisted implants (6.40 cm³) and significantly reduced in comparison with the conventionally shaped implants (13.48 cm³). The cosmetic appearance of the AR-assisted implants was rated as very good (median 25.00 out of 30 points) and significantly improved in comparison with the conventionally shaped implants (median 14.75 out of 30 points). Our experiments showed outstanding results regarding the possibilities of AR-assisted procedures for single-step reconstruction of craniofacial defects. Although patient-specific implants still represent the gold standard in esthetic aspects, AR-assisted procedures hold high potential for an immediately and widely available, cost-effective alternative providing excellent cosmetic outcomes.

State-of-Art of Standard and Innovative Materials Used in Cranioplasty

Cranioplasty is the surgical technology employed to repair a traumatic head injury, cerebrovascular disease, oncology resection and congenital anomalies. Actually, different bone substitutes are used, either derived from biological products such as hydroxyapatite and demineralized bone matrix or synthetic ones such as sulfate or phosphate ceramics and polymer-based substitutes. Considering that the choice of the best material for cranioplasty is controversial, linked to the best operation procedure, the intent of this review was to report the outcome of research conducted on materials used for such applications, comparing the most used materials. The most interesting challenge is to preserve the mechanical properties while improving the bioactivity, porosity, biocompatibility, antibacterial properties, lowering thickness and costs. Among polymer materials, polymethylmethacrylate and polyetheretherketone are the most motivating, due to their biocompatibility, rigidity and toughness. Other biomaterials, with ecofriendly attributes, such as polycaprolactone and polylactic acid have been investigated, due to their microstructure that mimic the trabecular bone, encouraging vascularization and cell-cell communications. Taking into consideration that each material must be selected for specific clinical use, the main limitation remains the defects and the lack of vascularization, consequently porous synthetic substitutes could be an interesting way to support a faster and wider vascularization, with the aim to improve patient prognosis.

Customized polymethylmethacrylate cranioplasty using a low-cost 3-dimensional printed mold

Introduction. Significant cranial defects result from a decompressive craniectomy following head trauma, malignant edema of the brain or intracranial hemorrhage, or resection of tumor affected bone. Unrepaired cranial defects are not just a tremendous esthetical problem. The underlying brain is unprotected, prone to injury, and this state can lead to the so-called ?syndrome of the trephined? with mood instability, headaches, and even a neurological deficit. Currently, there is no widely accepted uniform technique of cranial vault shape restoration. Combining 3D technology with the use of polymethylmethacrylate is a challenging field that can bring good functional and aesthetic results and, in the case of smart design, become efficient, low-cost technology. We offer a possible solution to a problem that would be acceptable in neurosurgical practice. Case outline. We present a 37-year-old male patient with a massive hemicranial defect as a consequence of previous decompressive craniectomy following severe craniocerebral injury. Together with engineers from the appropriate 3D modeling studio, we have designed a two-part mold by laser printing technology using biocompatible advanced polyamide. We made a customized polymethylmethacrylate graft intraoperatively using this mold and achieved good aesthetic results. Conclusion. Reports of 3D printing assisted cranioplasties are growing, describing different techniques and cost- estimation. We hope to introduce a low-cost and simple method for repairing a skull defect.