Planning Of Resection Research Articles

Customizable and Cost-effective Template for Fibular Osteotomies in Mandibular Reconstruction.

The free fibula flap is the gold standard for mandibular reconstruction in head and neck tumors. Traditionally, a titanium reconstruction plate is shaped to measure and align with the mandibular defect after ensuring proper occlusion. These prebent plates are matched against the fibula to estimate osteotomy sites and angles. This technique often requires repeated adjustments for optimal in-setting and heavily depends on the surgeon's experience. Advanced technology now allows virtual surgical planning with 3-dimensional simulation, enabling precise planning of resections and reconstructions. Computer-aided design/computer-aided manufacturing produces customized cutting guides and reconstruction plates. Although these technologies improve functional and aesthetic outcomes, they increase costs and preoperative preparation time. In resource-limited settings such as Pakistan, patients often present with advanced-stage cancers, making delays in guide manufacturing impractical. Alternative templates, such as tongue depressors and rulers, have been introduced but have limitations. We propose using folded x-ray films as templates for fibular osteotomies, offering a cost-effective, readily available alternative that yields satisfactory results.

A study on the morphometry and classification of variations of the suprascapular notch using computed tomography.

The suprascapular notch is one of the anatomical sites most commonly exposed to compressive and traction injuries of the suprascapular nerve. In this preliminary study, we aimed to evaluate the morphological and morphometric features of the notch to enhance the diagnostic accuracy and therapeutic outcomes of nerve compression. This retrospective study was conducted using computed tomography images of the scapula obtained between January 1, 2022, and August 30, 2024. A total of 852 scapulae were evaluated, of which 448 belonged to males and 404 to females. Morphometric measurements included superior transverse diameter, middle transverse diameter, and maximal depth of the notch. In addition, the notch was classified using both the Polguj and Rengachary classification systems. When the measurement parameters were compared between genders, the values were higher in males; however, only the maximal depth showed a statistically significant difference (p < 0.05). According to the Polguj classification, Type 3 was the most common (63.38%). Based on the Rengachary classification, the U-shaped form was the most frequently observed (65.02%), while the J-shaped form was the rarest (3.41%). The foramen shape was detected in 5.75% of cases. The J-shaped variant was found to be approximately four times more common in males than in females. Knowledge of the anatomical variations of the notch is likely to be beneficial for both endoscopic and open surgical interventions in the suprascapular region. In particular, three-dimensional computed tomography imaging may be useful in preoperative planning for arthroscopic resection of ossified ligament.

Brachial Plexus Lipoma Causing Neurological Impairment: A Case Series and Systematic Review.

Lipomas are benign adipocyte tumors that typically present as painless, firm nodules. In rare cases, lipomas may grow near the brachial plexus (BP) and compress various peripheral nerves. This can manifest as upper extremity motor and/or sensory deficits, numbness, tingling, or burning sensations. Surgical intervention of a brachial plexus lipoma (BPL) may be challenging because of variability in location and size. This study reviews previously reported cases of BPL causing neurological impairment and presents 5 additional cases, focusing on operative details and patient outcomes. A systematic review of PubMed, Scopus, and World of Science was performed to identify all previously reported cases of BP lipomas resulting in neurological deficit. A retrospective review of a neurosurgeon's prospectively collected database was conducted to identify all patients operated on for BPL. Patient demographics, tumor characteristics, presentation, surgical notes, and outcomes were collected for both reviews. Our literature review yielded 13 articles presenting at least one case meeting the eligibility criteria, resulting in 22 eligible patients. The surgeon's database provided an additional 5 patients meeting the criteria. Of the 27 total cases, 15 were men and 12 were women. The average age was 46.5 with a range of 25 to 70. All patients had upper extremity motor and/or sensory dysfunction preoperatively. Tumors were found in various regions, with the involvement of the supraclavicular fossa reported in 52% of cases. Gross tumor resection was achieved in all but 2 of the 27 operations. Four patients had a nonconventional lipoma type on histology. Sixteen patients experienced complete resolution of neurological symptoms. BP lipomas are rare but can cause a wide range of neurological symptoms depending on their size and location. A thorough patient examination and imaging studies are essential for creating a successful surgical plan for tumor resection.

White matter characterization in regions of edema surrounding meningioma brain tumor using diffusion MRI: A comparative study of DTI and NODDI.

White matter (WM) tract detection is critical in presurgical planning of tumor resection; however, standard-of-care diffusion tensor imaging (DTI) often fails to characterize white matter tracts through regions of edema. This is because the presence of edema has the effect of increasing the isotropic volume fraction within a voxel and thus marginalizing the anisotropic volume fraction associated with white matter presence and directionality. More recent biophysical models of diffusion, such as neurite orientation dispersion and density imaging (NODDI), account for isotropic and anisotropic volume fractions within voxels by compartmentalizing the diffusion signal based on an assumed tissue microenvironment, e.g., "free water" (cerebrospinal fluid (CSF), interstitial fluid (ISF), edema), "intra-neurite", and "extra-neurite" tissue, as a sphere, stick, and tensor, respectively. We hypothesize that a low fractional anisotropy (FA), low orientation dispersion index (ODI) value and high fractional isotropic volume (FISO) would be observed in white matter regions containing edema but a high FA, low ODI value and low FISO would be observed in healthy-appearing contralateral white matter. In our study, we test this hypothesis using multi-shell diffusion MRI data collected from patients bearing meningioma brains tumors. Brains bearing meningioma tumors are selected in this study as meningiomas rarely invade the brain parenchyma and we can thus assume that our analyses of edematous regions are not confounded by infiltrating tumor cells. Here, we show that NODDI-based characterization of white matter is more sensitive than that of standard-of-care DTI through regions of edema. Future studies will focus on implementation of biophysical model-based tractography in cases of glioma and translation of biophysical model-based tractography to the operating room.

Clinical practice of minimally invasive daytime hepatectomy based on enhanced recovery after surgery whole-process management scheme

Objective: To explore the clinical effect of the whole-process management scheme of daytime minimally invasive liver resection surgery based on the enhanced recovery after surgery (ERAS) concept. Methods: This is a retrospective case series study. The data of 55 patients who underwent minimally invasive daytime liver resection surgery under the ERAS concept at the Department of General Surgery,Sir Run Run Shaw Hospital, Zhejiang University School of Medicine from January 2023 to August 2024. There were 22 males and 33 females;aged (48.2±15.1) years (range: 16 to 77 years). All patients were classified as Grade 2 according to the American Society of Anesthesiologists physical status classification. Among them, 7 cases were complicated with liver cirrhosis and 10 cases had fatty liver. A multidisciplinary team was formed, consisting of surgeons, anesthesiologists, rehabilitation physicians, psychologists, pharmacists, acute pain management team, operating room nurses, day surgery ward nurses, and ERAS specialized nurses. After strict evaluation by surgeons and anesthesiologists, patients suitable for daytime liver resection surgery were implemented with the ERAS whole-process management plan for liver resection on the basis of routine nursing care. Results: Among the 55 patients, 50 were discharged smoothly within 48 hours, while 5 were transferred to specialized departments for further treatment due to not meeting the discharge criteria, with a smooth daytime discharge rate of 90.9%. Among the 50 patients, 30 underwent laparoscopic surgery and 20 underwent robotic-assisted surgery. The surgery time was (91.6±28.2)minutes(range:45 to 165 minutes), with the intraoperative blood loss of only (30.5±25.5)ml(range:5 to 100 ml). Pathological examination results showed that among the 50 patients, 13 cases had hepatocellular carcinoma, 21 cases had hepatic hemangioma, 4 cases had hepatic cyst, 8 cases had focal nodular hyperplasia, 1 case had low-grade dysplastic nodule, 1 case had hepatolithiasis, 1 case had lymphoma, and 1 case had vascular, fibrous and lymphoid tissue proliferation. There were 44.0% patients who were able to get out of bed on the day of surgery. The hospital stay was (1.8±0.4)days(range:1 to 2 days), and the hospitalization cost was (34 499±20 330)yuan(range:11 724 to 73 488 yuan). No complications requiring special treatment outside the conventional pathway were observed during the hospital stay and follow-up period. At the 2-week outpatient follow-up, no significant abnormalities were found in all patients, and the wound healing was good. Conclusions: The daytime liver resection surgery based on the ERAS whole-process management plan has shown good feasibility in clinical practice. It helps to simplify medical process, shorten hospital stay, and reduce medical costs.

Augmented reality in cranial surgery: Surgical planning and maximal safety in resection of brain tumors via head-mounted fiber tractography.

Augmented reality in cranial surgery: Surgical planning and maximal safety in resection of brain tumors via head-mounted fiber tractography.

Unsupervised detection of high-frequency oscillations in intracranial electroencephalogram: promoting a valuable automated diagnostic tool for epilepsy.

This study aims to develop an unsupervised automated method for detecting high-frequency oscillations (HFOs) in intracranial electroencephalogram (iEEG) signals, addressing the limitations of manual detection processes. The proposed method utilizes an unsupervised convolutional variational autoencoder (CVAE) model in conjunction with the short-term energy method (STE) to analyze two-dimensional time-frequency representations of iEEG signals. Candidate HFOs are identified using STE and transformed into time-frequency maps using the continuous wavelet transform (CWT). The CVAE model is trained for dimensionality reduction and feature reconstruction, followed by clustering of the reconstructed maps using the K-means algorithm for automated HFOs detection. Evaluation of the proposed unsupervised method on clinical iEEG data demonstrates its superior performance compared to traditional supervised models. The automated approach achieves an accuracy of 93.02%, sensitivity of 94.48%, and specificity of 92.06%, highlighting its efficacy in detecting HFOs with high accuracy. The unsupervised automated method developed in this study offers a reliable and efficient solution for detecting HFOs in iEEG signals, overcoming the limitations of manual detection processes of traditional supervised models. By providing clinicians with a clinically useful diagnostic tool, this approach holds promise for enhancing surgical resection planning in epilepsy patients and improving patient outcomes.

Localized soft tissue sarcomas

Soft tissue sarcomas are rare malignant tumors originating from mesenchymal tissue. They are mostly located in the extremities, followed by the trunk and retroperitoneal regions. The group of soft tissue sarcomas comprises over 80distinct histological subtypes, each with unique biological characteristics, with liposarcomas and leiomyosarcomas being the most frequent subtypes. In the clinical practice the algorithm from image, biopsy and (sarcoma) board has become established for the diagnostics of any soft tissue space-occupying lesion exceeding 3 cm in size. This enables the planning of awide R0 resection, which can be defined as the standard for sarcoma surgery. For locally advanced and/or frequently metastasizing tumors, (neo)adjuvant radiotherapy and/or chemotherapy are usually indicated. Patients benefit from asarcoma board to determine the treatment strategy. After treatment, clinical and radiological follow-ups should be conducted every 3-6months, depending on the grade of the primary tumor.

Fully Digital Workflow for an Immediate Implant-Retained Prosthesis Following Maxillectomy Resection Surgery.

This case report aimed to describe a digital workflow from 3D virtual surgical planning for tumor resection, maxillary implant placement, and an implant-retained prosthesis to fit the planned defect for immediate loading. A 68-year-old male was diagnosed with squamous cell carcinoma of the anterior maxilla. Intraoral scans and computed tomographs were taken preoperatively to digitally design and print a surgical resection guide, an implant placement guide, and a prosthetic bridge for immediate placement. The preoperative designed and manufactured prosthesis accurately matched the virtual surgical plan resection and implant positioning. The prosthesis could be placed and fixated for immediate loading. A 3-year follow-up found no locoregional recurrence, stability of the maxillary framework, and implants and prosthesis with a satisfactory aesthetic outcome. This case documents the importance of careful preoperative surgical planning and the opportunities for a fully digital workflow for oral cancer rehabilitation.

ILAE neuroimaging task force highlight: The utility of multimodal neuroimaging in diagnostic and presurgical workup of drug-resistant focal epilepsy.

The ILAE Neuroimaging Task Force publishes educational case reports that highlight basic aspects of neuroimaging in epilepsy, consistent with ILAE's educational mission. In patients with drug-resistant focal epilepsy who are candidates for surgical intervention, the identification of structural abnormalities is a strong predictor of favorable postoperative seizure outcomes. When conventional imaging is insufficient, the integration of multimodal neuroimaging data with structural, metabolic, and functional imaging modalities is often helpful. The following two illustrative cases from two different centers highlight the challenges and needs to integrate the information from multiple imaging modalities for a more accurate diagnosis and resection planning of drug-resistant focal epilepsies. This approach can increase the number of patients eligible for surgery while minimizing the risk of postoperative deficits.

Analysis of postoperative weight loss associated with prognosis after sublobar resections for lung cancer.

Sublobar resections for lung cancer are increasing worldwide. However, the prognostic significance of weight loss after sublobar resection remains unclear. We aimed to investigate the prognostic significance of weight loss after sublobar resection for lung cancer. Patients who underwent sublobar resection for non-small cell lung cancer between January 2016 and June 2021 were analysed. The percentage weight change at 3, 6, and 12months postoperatively was determined based on the preoperative weight. Patients were divided into two groups: those with or without weight loss ≥ 5%, referring to the diagnostic criteria for frailty, to assess prognosis. Subsequently, the prognosis-related timing of weight loss ≥ 5% and its risk factors were analyzed. We reviewed 147 patients; 39 (26.5%) showed weight loss ≥ 5% within 1-year post-surgery. A total of 32 patients (21.8%) died, 13 from primary lung cancer and 19 from non-lung cancer causes. Cancer recurrence occurred in 22 patients (15.0%). Weight loss ≥ 5% within 1-year post-surgery was a poor prognostic factor for overall and recurrence-free survival (log-rank; p = 0.014 and 0.018, respectively). Additionally, weight loss ≥ 5% at 6-12months postoperatively was associated with poor overall and recurrence-free survival (p < 0.05, both). In the multivariable analysis, an age-adjusted Charlson comorbidity index ≥ 4 was a predictive factor for weight loss ≥ 5% at 6-12months postoperatively (odds ratio, 3.920; p = 0.023). Weight loss ≥ 5% at 6-12months postoperatively was associated with poor prognosis. Long-term nutritional management is important in the treatment plan of sublobar resection in high-risk patients.

Characteristics of ResectionParameters in Robot-Assisted Total Knee Arthroplasty With the Ligament Balancing Workflow.

Robotic-assisted total knee arthroplasty (TKA) is a novel orthopedic technique. The workflow of robotic-assisted TKA is quite different from that of traditional manual TKA and may result incompletely different resection parameters. Understanding these parameters may help surgeons better perform robotic-assisted TKA. This study aims to analyze the specific resection parameters of robotic-assisted TKA. We retrospectively reviewed 85 MAKO-assisted TKA surgeries performed by three surgeons at our institution between May 2021 and November 2023. All patients had unilateral primary knee arthritis, and a Triathlon PS (Stryker) knee prosthesis was used. Intraoperative resection plan, radiological outcomes, and clinical outcomes were collected among them. The angle between the transepicondylar axis (TEA) and the femoral prosthesis axis was defined as rTEA, the angle between the posterior condylar axis (PCA) and the femoral prosthesis axis was defined as rPCA. The t-test and the Chi-square test (or Fisher's exact probability test) were used to determine differences in categorical variables. rTEA averaged 2.7° (range, 0°-6.7°), and rPCA averaged 4.9° (range, 0.2°-9.6°). The mean resection of the medial distal femur was 7.7 mm (range, 3.0-12.5), that of the lateral tibial plateau was 6.4 mm (range, 1.5-13.0), and that of the medial posterior condyle of the femur was 10.6 mm (range, 6.5-17.5), whereas that of the lateral posterior condyle of the femur was 6.7 mm (range, 2.0-13.0). Robotic-assisted TKA using the ligament balancing workflow generally resulted in greater external rotation than reported reference values for conventional manual TKA within the existing literature, with reference to both the TEA and PCA. In addition, tibial resection was generally less, and the joint line was generally shifted upwards.

Automatic future remnant segmentation in liver resection planning.

Liver resection is a complex procedure requiring precise removal of tumors while preserving viable tissue. This study proposes a novel approach for automated liver resection planning, using segmentations of the liver, vessels, and tumors from CT scans to predict the future liver remnant (FLR), aiming to improve pre-operative planning accuracy and patient outcomes. This study evaluates deep convolutional and Transformer-based networks under various computational setups. Using different combinations of anatomical and pathological delineation masks, we assess the contribution of each structure. The method is initially tested with ground-truth masks for feasibility and later validated with predicted masks from a deep learning model. The experimental results highlight the crucial importance of incorporating anatomical and pathological masks for accurate FLR delineation. Among the tested configurations, the best performing model achieves an average Dice score of approximately 0.86, aligning closely with the inter-observer variability reported in the literature. Additionally, the model achieves an average symmetric surface distance of 0.95 mm, demonstrating its precision in capturing fine-grained structural details critical for pre-operative planning. This study highlights the potential for fully-automated FLR segmentation pipelines in liver pre-operative planning. Our approach holds promise for developing a solution to reduce the time and variability associated with manual delineation. Such method can provide better decision-making in liver resection planning by providing accurate and consistent segmentation results. Future studies should explore its seamless integration into clinical workflows.

Patient-Specific Solutions for Cranial, Midface, and Mandible Reconstruction Following Ablative Surgery: Expert Opinion and a Consensus on the Guidelines and Workflow.

Reconstruction of cranio-maxillofacial defects following ablative surgeries requires a comprehensive approach that balances functional restoration with aesthetic outcomes. Advances in computer-aided design and manufacturing (CAD/CAM) technology have revolutionized this field, enabling precise preoperative planning, including 3D modeling, segmentation, and virtual resection planning. These methods allow for the production of patient-specific implants and surgical templates while facilitating the evaluation of treatment outcomes. CAD/CAM technology offers numerous benefits, such as enhanced surgical accuracy, improved aesthetic results, reduced operative times, and the possibility of single-stage resection and reconstruction. However, limitations exist, including high costs, the need for specialized expertise, and dependency on accurate imaging data. This paper provides a surgeon-centric evaluation of the advantages and limitations of CAD/CAM in cranio-maxillofacial reconstruction. The discussion encompasses the technological workflow, clinical applications, and recommendations for optimizing outcomes. Future perspectives highlight ongoing developments, such as integrating non-ionizing imaging techniques and expanding the applicability of virtual and augmented reality. By synthesizing technical advancements and clinical expertise, this review aims to establish practical guidelines for implementing CAD/CAM technology in routine surgical practice.

A111 EVALUATION OF REFERRAL COMPLETENESS FOR LARGE NON-PEDUNCULATED POLYPS IN LIGHT OF RECENT INTERNATIONAL CONSENSUS: A SINGLE-CENTER STUDY

Abstract Background Endoscopic mucosal resection (EMR) is standard-of-care for treating large non-pedunculated colorectal polyps yet often requires referral to expert centers. Hence, inclusion of important information to the therapeutic endoscopist is essential for pre-procedure planning. A recent international consensus statement, comprised of 19 components, aims to improve triage and planning of endoscopic resection for large non-pedunculated colorectal polyps. We sought to determine the current status of inclusion of these reporting elements in referrals to our tertiary center. Aims 1- Report the rate of complete referrals in light of the international expert consensus statement 2- Investigate the degree of correlation of polyp adjudication between referring endoscopist and local advance therapeutic endoscopiest assessment 3- Explore factors predicting comprehensive reporting Methods Single-center review of prospectively collected colorectal polyp referrals for large non-pedunculated polyps from March 2021 to March 2023. Results 411 referrals for large polyps were received; median size 3 cm; 58% located in ascending colon. 89 % of referrals included the initial assessment date, and only 38% incorporated video or photo documentation, of which 44% were deemed sufficient to demonstrate polyp features. Anatomical location was reported in 96% of referrals, while polyp size was mentioned in only half of the referrals (50%). Polyp morphology was described in 91% as either sessile (n=360) or pedunculated (n=35). Paris classification was reported in 53% of referrals, and LST classification in 90%. 12% of referrals reported four elements of less, while 18% of referrals reported all elements. Correlations with our own endoscopic assessments were diverse, ranging from a robust correlation for anatomical location (r=0.82, 95%CI 0.78-0.86, p &amp;lt; 0.001) to a more modest correlation for Paris classification (r=0.44, 95%CI 0.35-0.52 p &amp;lt; 0.001). Conclusions Our study reveals deficiencies in current referral practices and emphasizes the consensus statement’s role in improving the process. Consequences of low-quality referrals may include compromised patient care, leading to delayed diagnoses, inappropriate treatments, and potentially compromised patient outcomes. Thus, we have identified a likely knowledge gap in polyp characterization among referring physicians that will be a focus of a subsequent QI initiative. Funding Agencies None

Virtual Planning and Computer-Guided Surgery for Resection and Reconstruction of Craniomaxillofacial and Skull Base Tumors

Virtual Planning and Computer-Guided Surgery for Resection and Reconstruction of Craniomaxillofacial and Skull Base Tumors

Accuracy of virtual surgical planning for segmental mandibular resections: A comparison of connected resection guides versus separate resection guides in a cadaver study.

Accuracy of virtual surgical planning for segmental mandibular resections: A comparison of connected resection guides versus separate resection guides in a cadaver study.

Determination of adequate bony resection margins in inflammatory jaw pathologies using SPECT-CT in primary mandibular reconstruction with virtually planned vascularized bone flaps

ObjectivesIn advanced stages of osteoradionecrosis, medication-related osteonecrosis of the jaw, and osteomyelitis, a resection of sections of the mandible may be unavoidable. The determination of adequate bony resection margins is a fundamental problem because bony resection margins cannot be secured intraoperatively. Single-photon emission computed tomography (SPECT-CT) is more accurate than conventional imaging techniques in detecting inflammatory jaw pathologies. The clinical benefit for virtual planning of mandibular resection and primary reconstruction with vascularized bone flaps has not yet been investigated. This study aimed to evaluate the determination of adequate bony resection margins using SPECT computed tomography (SPECT-CT) for primary microvascular reconstruction of the mandible in inflammatory jaw pathologies.Materials and methodsThe cases of 20 patients with inflammatory jaw pathologies who underwent primary microvascular mandibular reconstruction after the bony resection margins were determined with SPECT-CT were retrospectively analyzed. The bony resection margins determined by SPECT-CT were histologically validated. The sensitivity was calculated as the detection rate and the positive predictive value as the diagnostic precision. Radiological ossification of the vascularized bone flaps with the mandibular stumps was assessed at least 6 months after reconstruction. The clinical course was followed for 12 months.ResultsThe determination of adequate bony resection margins with SPECT-CT yielded a sensitivity of 100% and a positive predictive value of 94.7%. Of all the bony resection margins, 97.4% were radiologically sufficiently ossified with the vascularized bone flap and showed no complications in the clinical course.ConclusionsSPECT-CT could increase the probability of determining adequate bony resection margins.Clinical relevanceSPECT-CT could have a beneficial clinical impact in the context of primary microvascular bony reconstruction in inflammatory jaw pathologies.

Enhancing Mandibular Reconstruction with Surgeon–Bioengineer Collaboration: A Protocol for Virtual Surgical Planning

Background/Objectives: Computer-assisted mandibular reconstruction requires sophisticated technical expertise alongside surgical knowledge. This study aims to establish and validate an efficient collaborative protocol between oral and maxillofacial surgeons and bioengineers for virtual surgical planning in mandibular reconstruction. Methods: We developed a structured protocol with four sequential phases: (1) generation of 3D models from CT data, (2) virtual resection planning, (3) reconstruction design, and (4) surgical guide fabrication. Protocol efficiency was assessed through seven simulation trials measuring planning duration and required revisions. Clinical validation was performed in four mandibular reconstruction cases. Accuracy was evaluated by comparing virtual surgical plans to postoperative outcomes using 3-matic 13.0 software analysis. Results: Protocol implementation showed consistent efficiency across simulations with a mean planning duration of 2.86 working days (SD = 1.35). Only two of seven simulations required design revisions. Clinical application in four cases (three ameloblastomas, one odontogenic myxoma) demonstrated high precision with a mean virtual-to-actual discrepancy of 0.90 mm (SD = 0.34). Successful reconstructions were achieved across varying defect spans (29–53 mm) using both bicortical deep circumflex iliac artery (DCIA) flaps and monocortical iliac block bone grafts. The collaborative workflow resulted in optimized surgical guide design, reduced planning iterations, and improved surgical precision. Conclusions: The established surgeon–bioengineer collaborative protocol enhances the efficiency and accuracy of computer-assisted mandibular reconstruction while making advanced surgical planning techniques more accessible. While initial results are promising, future studies with larger patient cohorts and extended follow-up periods are needed to fully validate the protocol’s long-term benefits and broader applicability.

Measuring Bound Attention During Complex Liver Surgery Planning: Feasibility Study.

The integration of advanced technologies such as augmented reality (AR) and virtual reality (VR) into surgical procedures has garnered significant attention. However, the introduction of these innovations requires thorough evaluation in the context of human-machine interaction. Despite their potential benefits, new technologies can complicate surgical tasks and increase the cognitive load on surgeons, potentially offsetting their intended advantages. It is crucial to evaluate these technologies not only for their functional improvements but also for their impact on the surgeon's workload in clinical settings. A surgical team today must increasingly navigate advanced technologies such as AR and VR, aiming to reduce surgical trauma and enhance patient safety. However, each innovation needs to be evaluated in terms of human-machine interaction. Even if an innovation appears to bring advancements to the field it is applied in, it may complicate the work and increase the surgeon's workload rather than benefiting the surgeon. This study aims to establish a method for objectively determining the additional workload generated using AR or VR glasses in a clinical context for the first time. Electroencephalography (EEG) signals were recorded using a passive auditory oddball paradigm while 9 participants performed surgical planning for liver resection across 3 different conditions: (1) using AR glasses, (2) VR glasses, and (3) the conventional planning software on a computer. The electrophysiological results, that is, the potentials evoked by the auditory stimulus, were compared with the subjectively perceived stress of the participants, as determined by the National Aeronautics and Space Administration-Task Load Index (NASA-TLX) questionnaire. The AR condition had the highest scores for mental demand (median 75, IQR 70-85), effort (median 55, IQR 30-65), and frustration (median 40, IQR 15-75) compared with the VR and PC conditions. The analysis of the EEG revealed a trend toward a lower amplitude of the N1 component as well as for the P3 component at the central electrodes in the AR condition, suggesting a higher workload for participants when using AR glasses. In addition, EEG components in the VR condition did not reveal any noticeable differences compared with the EEG components in the conventional planning condition. For the P1 component, the VR condition elicited significantly earlier latencies at the Fz electrode (mean 75.3 ms, SD 25.8 ms) compared with the PC condition (mean 99.4 ms, SD 28.6 ms). The results suggest a lower stress level when using VR glasses compared with AR glasses, likely due to the 3D visualization of the liver model. Additionally, the alignment between subjectively determined results and objectively determined results confirms the validity of the study design applied in this research.