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

Abstract

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.

Augmented Reality Integration in Skull Base Neurosurgery: A Systematic Review

“…In the laboratory studies on phantom skull models and cadaver studies, the accuracy of AR in defining normal anatomy of the SB structures or in the surgical approach to the SB was assessed. However, in a study by Steiert et al [22], defects were artificially created on the fronto-orbital area of the phantom skull models with extension to the SB, and a reconstruction of this defect was undertaken with AR. TRE values within the presented studies reveal notable variations in the accuracy of surgical navigation across different methodologies and virtual procedures.…”

Single-Center Experience in Microsurgical Resection of Acoustic Neurinomas and the Benefit of Microscope-Based Augmented Reality

“…Intraoperative checks of the navigation accuracy, especially on the bony landmarks of the petrous bone and internal auditory canal, enable navigation update and thus control over AR accuracy. One further application of AR for skull base surgery is in reconstruction of the cranial vault as a single-step procedure following resection of complex skull base lesions [29]. A study on 3D models with defects involving the anterior skull base, with modeling of AR-assisted and manually shaped implants for the repair of the defect from PMMA (Palacos ® R + G, Heraeus Medical GmbH, Wehrheim, Germany), has shown reduced deviation of the median volume from the profile of the surface of the original model in the case of an AR-assisted procedure compared to a "freehand" technique, with improved cosmetic results [29], which made this technique a viable and cost-effective alternative to patient-specific implants.…”

“…One further application of AR for skull base surgery is in reconstruction of the cranial vault as a single-step procedure following resection of complex skull base lesions [29]. A study on 3D models with defects involving the anterior skull base, with modeling of AR-assisted and manually shaped implants for the repair of the defect from PMMA (Palacos ® R + G, Heraeus Medical GmbH, Wehrheim, Germany), has shown reduced deviation of the median volume from the profile of the surface of the original model in the case of an AR-assisted procedure compared to a "freehand" technique, with improved cosmetic results [29], which made this technique a viable and cost-effective alternative to patient-specific implants. Operative videos which depict the use of AR for resection of skull base meningiomas have been published, depicting its use in intraoperative orientation through estimation of tumor size, estimation of tumor remnant throughout the resection, as well as relations to neurovascular structures, especially in surgery in and around bony structures, such as for estimation of the extent of drilling in extradural clinoidectomy [22,[30][31][32].…”

Mobile Devices or Head-Mounted Displays: A Comparative Review and Analysis of Augmented Reality in Healthcare

“…There are also numerous benefits to adopting either mobile-or HMD-based AR in healthcare. One of the benefits is its capability to offer 3D visualization [4], [35]- [37], [39], [44]- [46], [49], [51]- [53], [55]- [57], [59], [61]- [63], [67], [68], [70]. The ability to visualize an organ or tissue in 3D provides intuitive information to surgeons.…”

“…This setup made users to approach the wall for interaction, hindering the seamless integration of AR technology for patients confined to their beds [33]. In another study exploring the use of Magic Leap 1 for single-step repairs of facial skeleton and skull base defects, the manual alignment of real objects with holographic projections needed readjustment for each attempt [59]. This was not only time-consuming but also a potential source of errors.…”