Surgeons Combine Tumor Removal and 3D-Planned Skull Reconstruction in One Operation for Rare Orbital Meningiomas

Spheno-orbital meningiomas are among the most stubborn challenges in skull base surgery. These slow-growing tumors of the meninges, the protective membranes surrounding the brain, creep into the sphenoid wing of the skull and the bony walls of the orbit, the eye socket. As they infiltrate and thicken the bone, a process known as hyperostosis, they gradually push the eyeball forward, disfigure the face and threaten vision. Removing them has always demanded a delicate balancing act: the surgeon must strip out tumor and abnormal bone, relieve pressure inside the orbit, and then rebuild the skull and orbital framework so the patient’s face and eyesight survive the operation. A new study now reports that this entire sequence can be safely compressed into a single operation, with the help of computer-designed, patient-specific implants.

The research, published in the Journal of Neuro-Oncology, comes from a team led by Panagiotis Fistouris and senior author Uta Schick at the Department of Neurosurgery of Clemenshospital Muenster, an academic hospital of Muenster University in Germany, with collaborators from the University of Freiburg and Aristotle University of Thessaloniki. In a retrospective analysis of 34 patients treated for spheno-orbital meningiomas, the authors describe a standardized institutional protocol that merges two traditionally separate phases of care: microsurgical tumor resection and immediate cranio-orbital reconstruction using implants planned preoperatively with computer-aided design and computer-aided manufacturing, commonly abbreviated CAD/CAM.

The clinical problem these tumors pose is distinctive. Unlike many brain tumors whose danger lies in what they compress within the cranium, spheno-orbital meningiomas announce themselves largely through the eye. In this series, exophthalmos, the abnormal protrusion of the eyeball, was the predominant presenting symptom. The tumor’s bony overgrowth narrows the orbit from behind, shoving the eye forward and outward, and can also crowd the optic canal, the narrow bony tunnel through which the optic nerve travels from the eye to the brain. Left unchecked, the combination of proptosis, restricted eye movement and optic nerve compromise can produce progressive visual loss and profound cosmetic deformity, which is why surgical treatment typically requires not only tumor removal but also drilling away hyperostotic bone, decompressing the orbit and reconstructing the skull base.

Historically, that reconstruction has been the weak link. Surgeons have either shaped reconstructive materials free hand during the operation or deferred the cranio-orbital rebuild to a delayed second-stage procedure weeks or months later. Both strategies carry drawbacks. Free-hand reconstruction depends heavily on the operator’s judgment in the middle of a long operation, and results can fall short of ideal skull and facial symmetry. Staged procedures, meanwhile, expose patients to a second anesthesia, a second hospitalization and a longer overall recovery, while scar tissue and postoperative swelling from the first operation can make the delayed reconstruction harder to plan and execute accurately. The Muenster group’s protocol was designed to eliminate both problems by planning the entire operation, resection and reconstruction alike, on the computer before the patient ever enters the operating room.

The workflow hinges on preoperative imaging and digital modeling. Using the patient’s computed tomography data, the surgical team maps the extent of tumor infiltration and hyperostosis across the sphenoid wing and orbital walls, simulates the bony defects that will remain after resection and drilling, and then designs a patient-specific implant that will restore the contours of the orbit and cranial vault. The CAD/CAM process produces an implant whose geometry matches the anticipated defect, so that once the tumor is out and the abnormal bone is drilled away, the prosthesis can be seated immediately, restoring orbital volume and facial symmetry in the same anesthetic session. This approach builds on a growing body of work in which three-dimensional printing and computer-assisted design have been applied to customized bone reconstruction in spheno-orbital meningiomas and to single-step cranio-orbital reconstruction with patient-specific polyetheretherketone implants after resection of benign spheno-orbital tumors.

The results of applying this standardized protocol to 34 consecutive patients are striking in several respects. Gross-total resection, the complete removal of visible tumor, was achieved in 73.5 percent of cases, a respectable figure for lesions that infiltrate bone and wrap around critical structures at the skull base. More importantly for patients’ daily lives, the surgery delivered on its functional promises: exophthalmos was reduced in 85 percent of patients, and visual acuity improved in approximately 70 percent. For a disease whose most feared consequences are a bulging, disfigured eye and creeping blindness, those numbers represent a meaningful shift in what patients can expect from surgery.

The outcome data also lay bare the risks that remain inherent to operating in this crowded anatomical corridor. Postoperative amaurosis, blindness of the affected eye, occurred in 8.8 percent of patients, a sobering reminder of how vulnerable the optic nerve is during dissection around the optic canal and orbital apex. Transient diplopia, double vision, was far more common, affecting 55.9 percent of patients, presumably reflecting disturbance of the extraocular muscles and orbital mechanics during decompression and reconstruction. The double vision was temporary, but its frequency underscores that even a meticulously planned single-stage operation cannot fully insulate patients from the functional toll of major orbital surgery. Balancing aggressive bone and tumor removal against preservation of the delicate neurovascular structures threading through the orbit remains the central technical tension of this disease.

On the reconstruction side, however, the report is notably reassuring. The CAD/CAM implants demonstrated appropriate intraoperative fit, meaning the digitally designed prostheses matched the surgical defects as planned and could be positioned without improvisation. There were no major implant-related complications, and the authors report preservation of orbital and facial symmetry, the aesthetic goal that free-hand and delayed reconstruction approaches have historically struggled to guarantee consistently. The absence of implant-related problems in this cohort is particularly significant because cranial implants sit close to the brain, the eye and the paranasal sinuses, regions where malposition, infection or exposure can force revision surgery and undo the benefits of a single-stage strategy.

The authors conclude that single-stage resection with immediate CAD/CAM-assisted skull reconstruction for spheno-orbital meningiomas is feasible, safe and reproducible. The word reproducible matters as much as the others. Case reports of one-step tumor resection and cranio-orbital reconstruction with custom-made polymethylmethacrylate implants, and of image-guided meningioma resection with simultaneous computer-assisted cranio-orbital reconstruction, have appeared in the literature for nearly two decades, but scattered individual successes do not establish a standard of care. By codifying a standardized preoperative planning pathway and applying it uniformly across a series of patients, then auditing clinical, functional and radiological outcomes, the Muenster team has converted an ambitious concept into a protocol that other skull base centers can evaluate, adopt and refine. The authors suggest that combining tumor resection and patient-specific reconstruction within a single-stage procedure may offer practical advantages in the overall surgical pathway, sparing patients a second operation and its attendant risks, costs and delays.

Several caveats temper the enthusiasm. The study is retrospective, based on clinical data collected during routine patient care, and carries the limitations of that design, including the absence of randomization against alternative strategies and the possibility of selection effects in which patients were offered the combined procedure. The sample of 34 patients, while substantial for a rare tumor entity, is modest, and longer follow-up will be needed to confirm implant durability, tumor recurrence patterns and the stability of cosmetic and visual outcomes over years rather than months. The rates of transient diplopia and postoperative amaurosis also make clear that the single-stage approach does not by itself solve the fundamental surgical difficulty of spheno-orbital meningiomas; it reorganizes the treatment pathway around a technique that makes reconstruction more predictable. Even so, the study adds to a converging body of evidence, including systematic reviews of three-dimensional printing for customized bone reconstruction in these tumors and reports of augmented reality-assisted craniofacial reconstruction in skull base lesions, that digital planning and patient-specific implants are reshaping what is possible at the interface of neurosurgery, ophthalmology and reconstructive surgery. For patients facing a tumor that distorts both the skull and the face, the prospect of leaving the operating room with the disease removed and their anatomy restored in a single sitting is no longer a theoretical ambition but an increasingly documented clinical reality.

Subject of Research: Single-stage surgical resection and immediate CAD/CAM-assisted cranio-orbital reconstruction for spheno-orbital meningiomas

Article Title: Single-stage tumor resection and immediate CAD/CAM-assisted cranio-orbital reconstruction for spheno-orbital meningiomas: a standardized surgical workflow and outcome analysis

Article References: Fistouris, P., Ventura, E., Altayyar, A. A., Alanesi, A., Overstijns, M., Roelz, R., Brokinkel, B., & Schick, U. (2026). Single-stage tumor resection and immediate CAD/CAM-assisted cranio-orbital reconstruction for spheno-orbital meningiomas: a standardized surgical workflow and outcome analysis. Journal of Neuro-Oncology, 179(3), Article 91. https://doi.org/10.1007/s11060-026-05811-0

Image Credits: AI Generated

DOI: 10.1007/s11060-026-05811-0

Keywords: spheno-orbital meningioma, skull base surgery, CAD/CAM reconstruction, patient-specific implants, orbital decompression, exophthalmos, gross-total resection, visual acuity, 3D printing, neuro-oncology, cranioplasty, hyperostosis