Whole-Process Digitalization-Assisted Immediate Implant Placement and Immediate Restoration in the Aesthetic Zone: A Prospective Study.

BACKGROUND This study explored the clinical effects of whole-process digitalization (WD)-assisted immediate implant placement (IIP) and immediate restoration (IR) in the aesthetic zone and clarified the clinical procedures. MATERIAL AND METHODS Patients who received maxillary aesthetic region IIP and IR treatment were randomly distributed into WD-assisted and conventional groups. Postoperative assessment included implant accuracy, marginal bone loss, aesthetic evaluation, and patient satisfaction evaluation. The aesthetic evaluation included visual analog score (VAS), pink aesthetic score (PES), and white aesthetic score (WES). Numerical data, measurement data, and grade data were analyzed by χ² test, t test, and Mann-Whitney U test. RESULTS The WD-assisted group exhibited decreased implant accuracy, including coronal deviation, apical deviation, angular deviation, and depth deviation, compared with the conventional group (P<0.05). The marginal bone loss in both the mesiodistal direction and the buccolingual direction were significantly lower in the WD-assisted group than in the conventional group (P<0.05). The VAS, PES, and WES were all significantly higher in the WD-assisted group than in the conventional group at 3, 6, and 12 months after surgery (P<0.05). Patients in the WD-assisted group also reported a higher satisfaction level than those in the conventional group (P<0.05). CONCLUSIONS WD-assisted IIP and IR treatment in the aesthetic zone increased implant accuracy, decreased marginal bone loss, improved aesthetic effect, and increased patient satisfaction compared with conventional treatment. Therefore, WD-assisted IIP and IR treatment constitutes a promising approach in clinical oral implantology.

Chinese expert consensus of image-guided irreversible electroporation for pancreatic cancer.

Pancreatic cancer (PC) is a lethal disease with extremely high mortality. Although surgical resection is the optimal therapeutic approach for PC, about 30%-40% of those patients are not candidates for surgical resection when diagnosed. Chemotherapy and radiotherapy also could not claim a desirable effect on PC. The application of interventional radiology approaches is limited by unavoidable damage to the surrounding vessels or organs. By the superiority of mechanism and technology, IRE could ablate the tumor by creating irreversible pores on the membrane of PC cells with other tissues like vessels and pancreatic ducts untouched. This consensus gathers the theoretical basis and clinical experience from multiple Chinese medical centers, to provide the application principles and experience from Chinese experts in the IRE field.

Individualized ablation strategy to treat persistent atrial fibrillation: Core-to-boundary approach guided by charge-density mapping.

BACKGROUND: Noncontact charge-density mapping allows rapid real-time global mapping of atrial fibrillation (AF), offering the opportunity for a personalized ablation strategy. OBJECTIVE: The purpose of this study was to compare the 2-year outcome of an individualized strategy consisting of pulmonary vein isolation (PVI) plus core-to-boundary ablation (targeting the conduction pattern core with an extension to the nearest nonconducting boundary) guided by charge-density mapping, with an empirical PVI plus posterior wall electrical isolation (PWI) strategy. METHODS: Forty patients (age 62 ± 12 years; 29 male) with persistent AF (10 ± 5 months) prospectively underwent charge-density mapping-guided PVI, followed by core-to-boundary stepwise ablation until termination of AF or depletion of identified cores. Freedom from AF/atrial tachycardia (AT) at 24 months was compared with a propensity score-matched control group of 80 patients with empirical PVI + PWI guided by conventional contact mapping. RESULTS: Acute AF termination occurred in 8 of 40 patients after charge-density mapping-guided PVI alone and in 21 of the remaining 32 patients after core-to-boundary ablation in the study cohort, compared with 8 of 80 (10%) in the control cohort (P <.001). On average, 2.2 ± 0.6 cores were ablated post-PVI before acute AF termination. At 24 months, freedom from AF/AT after a single procedure was 68% in the study group vs 46% in the control group (P = .043). CONCLUSION: An individualized ablation strategy consisting of PVI plus core-to-boundary ablation guided by noncontact charge-density mapping is a feasible and effective strategy for treating persistent AF, with a favorable 24-month outcome.

Intraoperative Magnetic Resonance Imaging for Low-Grade and High-Grade Gliomas: What Is the Evidence? A Meta-Analysis.

BACKGROUND: The benefit of intraoperative magnetic resonance imaging (iMRI) in gliomas remains unclear. We performed a meta-analysis of outcomes with iMRI-guided surgery in high-grade gliomas (HGGs) and low-grade gliomas (LGGs). METHODS: Databases were searched until November 29, 2018 for randomized controlled trials (RCTs) and observational studies (OBS) comparing iMRI use with conventional neurosurgery. Pooled risk ratios (RRs) or hazard ratios were evaluated with the random-effects model. Outcomes included extent of resection (EOR), gross total resection (GTR), progression-free survival (PFS), overall survival (OS), and length of surgery (LOS), stratified by study design and glioma grade. RESULTS: Fifteen articles (3 RCTs and 12 OBS) were included. In RCTs, GTR was higher in iMRI compared with conventional neurosurgery (RR, 1.42; 95% confidence interval [CI], 1.17-1.73; I2, 7%) overall, for LGGs (1.91; 95% CI, 1.19-3.06), but not HGGs (1.24; 95% CI, 0.89-1.73), with no difference in EOR, PFS, OS, and LOS. For OBS, GTR was higher (RR, 1.65; 95% CI, 1.43-1.90; I2, 4%) overall, and for LGGs (1.63; 95% CI, 1.17-2.28; I2, 0%) and HGGs (1.62; 95% CI, 1.36-1.92; I2, 19%). EOR was greater with iMRI (6%; 95% CI, 4%-8%; I2, 44%) overall, in LGGs (5%; 95% CI, 2%-8%; I2, 37%) and HGGs (7%; 95% CI, 4%-10%; I2, 13%). There was no difference in PFS, OS, and LOS with iMRI. CONCLUSIONS: IMRI use improved GTR in gliomas, including LGGs. However, no PFS and OS benefit was shown in the meta-analysis.

Cell-Based Tracers as Trojan Horses for Image-Guided Surgery.

Surgeons rely almost completely on their own vision and palpation to recognize affected tissues during surgery. Consequently, they are often unable to distinguish between different cells and tissue types. This makes accurate and complete resection cumbersome. Targeted image-guided surgery (IGS) provides a solution by enabling real-time tissue recognition. Most current targeting agents (tracers) consist of antibodies or peptides equipped with a radiolabel for Positron Emission Tomography (PET) and Single Photon Emission Computed Tomography (SPECT), magnetic resonance imaging (MRI) labels, or a near-infrared fluorescent (NIRF) dye. These tracers are preoperatively administered to patients, home in on targeted cells or tissues, and are visualized in the operating room via dedicated imaging systems. Instead of using these 'passive' tracers, there are other, more 'active' approaches of probe delivery conceivable by using living cells (macrophages/monocytes, neutrophils, T cells, mesenchymal stromal cells), cell(-derived) fragments (platelets, extracellular vesicles (exosomes)), and microorganisms (bacteria, viruses) or, alternatively, 'humanized' nanoparticles. Compared with current tracers, these active contrast agents might be more efficient for the specific targeting of tumors or other pathological tissues (e.g., atherosclerotic plaques). This review provides an overview of the arsenal of possibilities applicable for the concept of cell-based tracers for IGS.

IVUS-Guided Wiring Improves the Clinical Outcomes of Angioplasty for Long Femoropopliteal CTO Compared with the Conventional Intraluminal Approach.

AIMS: This study aimed to assess the clinical efficacy of intravascular ultrasound (IVUS)-guided intraplaque wiring for femoropopliteal (FP) chronic total occlusion (CTO). METHODS: This single-center, retrospective, observational study was performed at the Japanese Red Cross Kyoto Daini Hospital. From March 2013 to June 2017, a total of 75 consecutive patients (mean age: 75.4±8.5 years; 59 males), who underwent endovascular treatment (EVT), having 82 de novo FP-CTO lesions, were enrolled in this study. Eleven of the lesions that met the exclusion criteria were excluded, and the remaining 71 lesions were divided into the IVUS-guided wiring group (n=34) and non-IVUS-guided wiring group (n=37). Primary patency, defined as a peak systolic velocity ratio of ＜2.4 on duplex ultrasonography, and freedom from clinically driven target lesion revascularization (CD-TLR) at 12 months were the primary outcomes. RESULTS: The mean lesion length was 21.6±8.9 cm. The frequencies of primary patency and freedom from CD-TLR were significantly higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (70.0% vs. 52.2%, p=0.045; 83.9% vs. 62.8%, p=0.036, respectively). The complete clinically true lumen angioplasty rate was also higher in the IVUS-guided wiring group than in the non-IVUS-guided wiring group (91.1% vs. 51.3%, p＜0.001, respectively). The clinically true and false wire passage rates were respectively 97.3% and 2.7% in the IVUS-guided wiring group. CONCLUSION: IVUS-guided wiring improves the clinical outcomes of EVT for FP-CTO by achieving a high clinically true lumen wire passage rate.

Use of Intraoperative CT Improves Accuracy of Spinal Navigation During Screw Fixation in Cervico-thoracic Region.

STUDY DESIGN: A retrospective analysis of a single-center consecutive series of patients. OBJECTIVE: To test the hypothesis that using a mobile intraoperative computed tomography in combination with spinal navigation would result in better accuracy of lateral mass and pedicle screws between C3 and T5 levels, compared to cone-beam computed tomography and traditional 2D fluoroscopy. SUMMARY OF BACKGROUND DATA: Use of spinal navigation associated with 3D imaging has been shown to improve accuracy of screw positioning in the cervico-thoracic region. However, use of iCT imaging compared to a cone-beam CT has not been fully investigated in these types of surgical interventions. METHODS: We retrospectively analyzed a series of patients who underwent posterior cervico-thoracic fixations using different intraoperative imaging systems in a single hospital. We identified three different groups of patients: Group A, operated under 2D-fluoroscopic guidance without navigation; Group B: O-arm guidance with navigation; Group C: iCT AIRO guidance with navigation. Primary outcome was the rate of accurately placed screws, measured on intra or postoperative CT scan with Neo et al. classification for cervical pedicles screws and Gertzbein et al. for thoracic pedicle screws. Screws in cervical lateral masses were evaluated according to a new classification created by the authors. RESULTS: Data on 67 patients and 495 screws were available. Overall screw accuracy was 92.8% (95.6% for lateral mass screws, 81.6% for cervical pedicle screws, and 90% for thoracic pedicle screws). Patients operated with iCT AIRO navigation had significantly fewer misplaced screws (2.4%) compared to 2D-fluoroscopic guidance (9.1%) and O-arm navigation (9.7%) (P = 0.0152). Accuracy rate of iCT navigation versus O-arm navigation was significantly higher (P = 0.0042), and there was no statistically significant difference in surgical time between the three Groups (P = 0.5390). CONCLUSION: Use of high-quality CT associated with spinal navigation significantly improved accuracy of screw positioning in the cervico-thoracic region.Level of Evidence: 3.

Intersurgeon and intrasurgeon variability in preoperative planning of anatomic total shoulder arthroplasty: a quantitative comparison of 49 cases planned by 9 surgeons.

BACKGROUND: Preoperative planning software is widely available for most anatomic total shoulder arthroplasty (ATSA) systems. It can be most useful in determining implant selection and placement with advanced glenoid wear. The purpose of this study was to quantify inter- and intrasurgeon variability in preoperative planning of a series of ATSA cases. METHODS: Forty-nine computed tomography scans were planned for ATSA by 9 fellowship-trained shoulder surgeons using the ExactechGPS platform (Exactech Inc., Gainesville, FL, USA). Each case was planned a second time between 4 and 12 weeks later. Variability within and between surgeons was measured for implant type, size, version and inclination correction, and implant face position. Interclass correlation coefficients, Pearson, and Light's kappa coefficients were used for statistical analysis. RESULTS: There was considerable variation in the frequency of augment use between surgeons and between rounds for the same surgeon. Thresholds for augment use also varied between surgeons. Interclass correlation coefficients for intersurgeon variability were 0.37 for version, 0.80 for inclination, 0.36 for implant type, and 0.36 for implant size. Pearson coefficients for intrasurgeon variability were 0.17 for version and 0.53 for inclination. Light's kappa coefficient for implant type was 0.64. CONCLUSIONS: This study demonstrates substantial inter- and intrasurgeon variability in preoperative planning of ATSA. Although the magnitude of differences in correction was small, surgeons differed significantly in the use of augments to achieve the resultant plan. Surgeons differed from each other on thresholds for augment use and maximum allowable residual retroversion. This suggests that there may a range of acceptable corrections for each shoulder rather than a single optimal plan.

Design and Validation of a Spinal Surgical Navigation System Based on Spatial Augmented Reality.

STUDY DESIGN: Prospective observational study. OBJECTIVE: This article aims to develop a spatial augmented reality-based surgical navigation system to assist in the placement of pedicle screws in minimally invasive spine surgery and to verify the accuracy of this method. SUMMARY OF BACKGROUND DATA: Due to their high accuracy and good visualization ability, augmented reality surgical navigation systems have been used in minimally invasive surgeries. However, augmented reality does not allow information to be shared and restricts doctors. METHODS: A surgical navigation system that implements augmented reality based on a projector can be used to realize the external visualization of virtual organs and surgical information through an improved multiple information fusion method. Using fiducial markers and imaging technology, the patient's spatial position is tracked and registered in real time. All the information is accurately fused with the patient's back skin, and the surgeon can see surgical information such as the preoperative plan and bones. Phantom experiments were used to verify the accuracy and effectiveness of the system. RESULTS: In the phantom experiments, the accuracy of the pedicle screw insertion point on the dummy's skin was 0.441 ±â€Š0.214 mm, the average location error into the dummy's body was 1.645 ±â€Š0.355 mm, and the average axial and sagittal angulation errors were <0.9°. CONCLUSION: This article introduces and verifies the design of a new surgical navigation system based on spatial augmented reality for lumbar pedicle screw implantation. The system passed a series of phantom accuracy experiments. Compared with the traditional augmented reality navigation system, this system avoids the use of glasses and truly realizes the effect of naked-eye 3D, which is more convenient for doctors to use for communication during an operation. LEVEL OF EVIDENCE: N/A.

Incisionless MR-guided focused ultrasound: technical considerations and current therapeutic approaches in psychiatric disorders.

INTRODUCTION: MR-guided focused ultrasound operating at higher intensities have been reported to effectively and precisely ablate deeper brain structures like the basal ganglia or the thalamic nuclei for the treatment of refractory movement disorders, neuropathic pain and most recently neuropsychiatric disorders, while low-intensity focused ultrasound represents an approach promoting mechanical blood-brain-barrier opening and neuromodulation. This narrative review summarizes the technical development and the therapeutic potential of incisionless MRgFUS in order to treat neuropsychiatric disorders. AREAS COVERED: A narrative review of clinical trials assessing the safety and efficacy of MRgFUS. A literature review was performed using the following search terms: MR-guided focused ultrasound, psychiatric disorders, noninvasive and invasive brain modulation/stimulation techniques. EXPERT OPINION: MRgFUS ablation is under clinical investigation (unblinded study design) for obsessive-compulsive disorders (OCDs) [capsulotomy; ALIC] and depression/anxiety disorders [capsulotomy] and has demonstrated an improvement in OCD and depression, although of preliminary character. Low-intensity ultrasound applications have been explored in Alzheimer´s disease (phase 1 study) and healthy subjects. Currently, limited evidence hinders comparison and selection between MRgFUS and noninvasive/invasive brain modulation therapies. However, comparative, sham-controlled trials are needed to reexamine the preliminary findings for the treatment of psychiatric disorders.

Does Augmented Reality Navigation Increase Pedicle Screw Density Compared to Free-Hand Technique in Deformity Surgery? Single Surgeon Case Series of 44 Patients.

STUDY DESIGN: Retrospective comparison between an interventional and a control cohort. OBJECTIVE: The aim of this study was to investigate whether the use of an augmented reality surgical navigation (ARSN) system for pedicle screw (PS) placement in deformity cases could alter the total implant density and PS to hook ratio compared to free-hand (FH) technique. SUMMARY OF BACKGROUND DATA: Surgical navigation in deformity surgery provides the possibility to place PS in small and deformed pedicles were hooks would otherwise have been placed, and thereby achieve a higher screw density in the constructs that may result in better long-term patient outcomes. METHODS: Fifteen deformity cases treated with ARSN were compared to 29 cases treated by FH. All surgeries were performed by the same orthopedic spine surgeon. PS, hook, and combined implant density were primary outcomes. Procedure time, deformity correction, length of hospital stay, and blood loss were secondary outcomes. The surgeries in the ARSN group were performed in a hybrid operating room (OR) with a ceiling-mounted robotic C-arm with integrated video cameras for AR navigation. The FH group was operated with or without fluoroscopy as deemed necessary by the surgeon. RESULTS: Both groups had an overall high-density construct (>80% total implant density). The ARSN group, had a significantly higher PS density, 86.3% ±â€Š14.6% versus 74.7% ±â€Š13.9% in the FH group (P < 0.05), whereas the hook density was 2.2% ±â€Š3.0% versus 9.7% ±â€Š9.6% (P < 0.001). Neither the total procedure time (min) 431 ±â€Š98 versus 417 ±â€Š145 nor the deformity correction 59.3% ±â€Š16.6% versus 60.1% ±â€Š17.8% between the groups were significantly affected. CONCLUSION: This study indicates that ARSN enables the surgeon to increase the PS density and thereby minimize the use of hooks in deformity surgery without prolonging the OR time. This may result in better constructs with possible long-term advantage and less need for revision surgery. LEVEL OF EVIDENCE: 3.

Optimization Model for the Distribution of Fiducial Markers in Liver Intervention.

The distribution of fiducial markers is one of the main factors affected the accuracy of optical navigation system. However, many studies have been focused on improving the fiducial registration accuracy or the target registration accuracy, but few solutions involve optimization model for the distribution of fiducial markers. In this paper, we propose an optimization model for the distribution of fiducial markers to improve the optical navigation accuracy. The strategy of optimization model is reducing the distribution from three dimensional to two dimensional to obtain the 2D optimal distribution by using optimization algorithm in terms of the marker number and the expectation equation of target registration error (TRE), and then extend the 2D optimal distribution in two dimensional to three dimensional to calculate the optimal distribution according to the distance parameter and the expectation equation of TRE. The results of the experiments show that the averaged TRE for the human phantom is approximately 1.00 mm by applying the proposed optimization model, and the averaged TRE for the abdominal phantom is 0.59 mm. The experimental results of liver simulator model and ex-vivo porcine liver model show that the proposed optimization model can be effectively applied in liver intervention.

New perspectives on surgical accuracy analysis of image-guided bone tumour resection surgery.

PURPOSE: Image-guided bone tumour resection surgery has been proved in previous literatures to be more accurate than those conventional freehand ones (p < 0.001). However, in this kind of surgery, there are still many procedures depending on manual operations, which will inevitably introduce surgical errors into the surgery. In particular, the negative surgical errors (i.e., errors toward tumour) would increase the risk of tumor recurrence and metastasis. Thus, the first purpose of this study was to evaluate whether the negative surgical errors of image-guided bone tumour resection surgery were statistically significantly great, the second purpose is to evaluate whether the negative surgical errors of image-guided long-bone tumour resection surgery were statistically equivalent to those of pelvis surgery, and the last purpose is to recommend a solution for suppressing these errors when using a navigation system. METHODS: Negative surgical errors of 24 osteotomies in ten pelvis tumour resection operations and 16 osteotomies in ten long-bone surgeries under the image guidance of a navigation system were statistically evaluated and compared with - 2.0 mm. The equivalence of negative surgical errors of pelvis group and those of long-bone group was statistically tested. To suppress these negative surgical errors when using a navigation system, we recommend, based on the obtained statistics, to increase the margins between cut planes and tumour boundary during pre-operatively planning cut planes, by adding an extra margin with the empirical safe margin according to the absolute lower bound of 95% CI of negative surgical errors. RESULTS: Negative surgical errors of the pelvis group and the long-bone group were both significantly less than - 2.0 mm (p < 0.001), but not statistically equivalent (Rg > 1 mm). 95% CI of negative surgical errors were from - 3.95 to - 3.27 mm for the pelvis group, and from - 2.69 to - 2.34 mm for the long-bone group. So, the extra margin added for image-guided pelvis tumour resection surgery should be set as 3.95 mm, and the extra margin added for image-guided long-bone surgery should be set as 2.69 mm. CONCLUSION: The negative surgical errors of image-guided bone resection surgery were statistically significantly less than - 2.0 mm (p < 0.001), thus these errors cannot be safely ignored. Moreover, the negative surgical errors of the pelvis group were not equivalent to those of the long-bone group (Rg > 1.0 mm), thus the solution for image-guided pelvis tumour resection surgery and that for image-guided long-bone tumour resection surgery should be separately determined. In order to suppress these negative surgical errors when using a navigation system, we recommend to add extra 3.95 mm margin with the empirical safe margin for image-guided pelvis tumour resection surgery and to add extra 2.69 mm margin for image-guided long-bone tumour resection surgery during pre-operatively planning cut planes.

Conventional instruments are more accurate for measuring the depth of the tibial cut than computer-assisted surgery in total knee arthroplasty: a prospective study.

INTRODUCTION: The most commonly used tool for implant positioning are conventional instruments (CI) followed by computer-assisted surgery (CAS). A number of studies have investigated the cutting error of the tibial component when CAS is used, but most of them were focused on the cutting angles. The accuracy of CAS to determine the depth of the cut has not received much attention, even though implications are similar or worse, than with an angle mismatch. MATERIALS AND METHODS: This was an ethics board approved, prospective study of 23 consecutive varus TKAs by a single surgeon. Implant positioning was performed using CAS; however, the depth of the tibial cut was determined with both CAS and CI. Targeted alignment was the mechanical axis and 3° of posterior slope. The planned and the achieved cut, as determined by CAS needed to match. The achieved cut was then measured using a caliper and compared to the depth of the cut as per CAS. Medial and lateral cuts were analyzed separately. Analysis of variance and Bland-Altman plots were used for the comparison. RESULTS: Mean medial navigated cut was 6.3 (± 2.2) mm, mean measured medial cut was 6.6 (± 2.3) mm. Mean lateral navigated cut was 8.9 (± 1.8) mm, mean measured lateral cut was 8.8 (± 1.5) mm. There was a statistical significance for both the medial (p < 0.001) and the lateral (p = 0.004) navigated and measured cuts. CONCLUSIONS: The results of this study suggest that the tibial cut depth, measured by the navigation, does not match the actual bony cuts performed, even if a perfect cut was achieved in both sagittal and coronal plane. Surgeons should be aware of the measurement error in the navigation system and potentially add an additional step for verifying the achieved depth of the cut.

Augmented Reality Forward Damage Control Procedures for Nonsurgeons: A Feasibility Demonstration.

INTRODUCTION: This article presents an emerging capability to project damage control procedures far forward for situations where evacuation to a formal surgical team is delayed. Specifically, we demonstrate the plausibility of using a wearable augmented reality (AR) telestration device to guide a nonsurgeon through a damage control procedure. METHODS: A stand-alone, low-profile, commercial-off-the-shelf wearable AR display was utilized by a remotely located surgeon to synchronously guide a nonsurgeon through proximal control of the distal external iliac artery on a surgical manikin. The manikin wound pattern was selected to simulate a rapidly exsanguinating junctional hemorrhage not controllable by nonsurgical means. RESULTS: This capability demonstration displayed successful use of AR technology, telecommunication, and procedural training and guidance in a single test pilot. The assisted physician assistant was able to rapidly control the simulated external iliac artery injury on this model. The telestration system used was commercially available for use with available civilian cell phone, wireless and satellite networks, without the need for dedicated high-speed networks. CONCLUSIONS: A nonsurgeon, using a wearable commercial on-visual-axis telestration system, successfully performed a damage control procedure, demonstrating the plausibility of this approach.

Computer-assisted planning for minimally invasive anterior two-thirds laser corpus callosotomy: A feasibility study with probabilistic tractography validation.

BACKGROUND: Anterior two-thirds corpus callosotomy is an effective palliative neurosurgical procedure for drug-refractory epilepsy that is most commonly used to treat drop-attacks. Laser interstitial thermal therapy is a novel stereotactic ablative technique that has been utilised as a minimally invasive alternative to resective and disconnective open neurosurgery. Case series have reported success in performing laser anterior two-thirds corpus callosotomy. Computer-assisted planning algorithms may help to automate and optimise multi-trajectory planning for this procedure. OBJECTIVE: To undertake a simulation-based feasibility study of computer-assisted corpus callostomy planning in comparison with expert manual plans in the same patients. METHODS: Ten patients were selected from a prospectively maintained database. Patients had previously undergone diffusion-weighted imaging and digital subtraction angiography as part of routine SEEG care. Computer-assisted planning was performed using the EpiNav™ platform and compared to manually planned trajectories from two independent blinded experts. Estimated ablation cavities were used in conjunction with probabilistic tractography to simulate the expected extent of interhemispheric disconnection. RESULTS: Computer-assisted planning resulted in significantly improved trajectory safety metrics (risk score and minimum distance to vasculature) compared to blinded external expert manual plans. Probabilistic tractography revealed residual interhemispheric connectivity in 1/10 cases following computer-assisted planning compared to 4/10 and 2/10 cases with manual planning. CONCLUSION: Computer-assisted planning successfully generates multi-trajectory plans capable of LITT anterior two-thirds corpus callosotomy. Computer-assisted planning may provide a means of standardising trajectory planning and serves as a potential new tool for optimising trajectories. A prospective validation study is now required to determine if this translates into improved patient outcomes.

Best practices in near-infrared fluorescence imaging with indocyanine green (NIRF/ICG)-guided robotic urologic surgery: a systematic review-based expert consensus.

PURPOSE: The aim of the present study is to investigate the impact of the near-infrared (NIRF) technology with indocyanine green (ICG) in robotic urologic surgery by performing a systematic literature review and to provide evidence-based expert recommendations on best practices in this field. METHODS: All English language publications on NIRF/ICG-guided robotic urologic procedures were evaluated. We followed the PRISMA (Preferred Reporting Items for Systematic Review and Meta-Analyses) statement to evaluate PubMed®, Scopus® and Web of Science™ databases (up to April 2019). Experts in the field provided detailed pictures and intraoperative video-clips of different NIRF/ICG-guided robotic surgeries with recommendations for each procedure. A unique QRcode was generated and linked to each underlying video-clip. This new exclusive feature makes the present the first "dynamic paper" that merges text and figure description with their own video providing readers an innovative, immersive, high-quality and user-friendly experience. RESULTS: Our electronic search identified a total of 576 papers. Of these, 36 studies included in the present systematic review reporting the use of NIRF/ICG in robotic partial nephrectomy (n = 13), robotic radical prostatectomy and lymphadenectomy (n = 7), robotic ureteral re-implantation and reconstruction (n = 5), robotic adrenalectomy (n = 4), robotic radical cystectomy (n = 3), penectomy and robotic inguinal lymphadenectomy (n = 2), robotic simple prostatectomy (n = 1), robotic kidney transplantation (n = 1) and robotic sacrocolpopexy (n = 1). CONCLUSION: NIRF/ICG technology has now emerged as a safe, feasible and useful tool that may facilitate urologic robotic surgery. It has been shown to improve the identification of key anatomical landmarks and pathological structures for oncological and non-oncological procedures. Level of evidence is predominantly low. Larger series with longer follow-up are needed, especially in assessing the quality of the nodal dissection and the feasibility of the identification of sentinel nodes and the impact of these novel technologies on long-term oncological and functional outcomes.

Improved Accuracy of Cervical Spinal Surgery With Robot-Assisted Screw Insertion: A Prospective, Randomized, Controlled Study.

STUDY DESIGN: Prospective, randomized, controlled trial. OBJECTIVE: To compare robot-assisted and conventional implantation techniques by evaluating the accuracy and safety of implanting screws in cervical vertebrae. SUMMARY OF BACKGROUND DATA: Cervical spinal surgery is difficult and dangerous as screw misplacement might lead not only to decreased stability but also neurological, vascular, and visceral injuries. A new robot-assisted surgical procedure has been introduced to improve the accuracy of implant screw positioning. METHODS: We randomly assigned 135 patients with newly diagnosed cervical spinal disease and who required screw fixation using either robot-assisted or conventional fluoroscopy-assisted cervical spinal surgery. The primary outcomes were the discrepancies between the planned trajectories and the actual screw positions. RESULTS: Altogether, 127 patients underwent the assigned intervention (61 robot-assisted and 66 conventional fluoroscopy-assisted). The baseline characteristics including the screw types, were similar in the two groups. Altogether, 390 screws were planed and placed in the cervical vertebrae, and 94.9% were acceptable. The robot-assisted group had a better screw placement accuracy than the conventional fluoroscopy-assisted group with associated P values <0.001 (0.83 [0.44, 1.29] vs. 1.79 [1.41, 2.50] mm). The Gertzbein and Robbins scales also showed a significant difference between the two groups (P < 0.001). Furthermore, the robot-assisted group experienced significantly less blood loss during surgery than the conventional fluoroscopy-assisted group (200 [50, 375] vs. 350 [100, 500] mL; P = 0.002) and shorter length of stay after surgery (P = 0.021). These two groups did not differ significantly regarding the duration of the operation (P = 0.525). Neurological injury occurred in one case in the conventional fluoroscopy-assisted group. CONCLUSION: The accuracy and clinical outcomes of cervical spinal surgery using the robot-assisted technique tended to be superior to those with the conventional fluoroscopy-assisted technique in this prospective, randomized, controlled trial. LEVEL OF EVIDENCE: 2.

Identifying the Sources of Error When Using 3-Dimensional Printed Head Models with Surgical Navigation.

OBJECTIVES: The evaluation of sources of error when preparing, printing, and using 3-dimensional (3D) printed head models for training purposes. METHODS: Two 3D printed models were designed and fabricated using actual patient imaging data with reference marker points embedded artificially within these models that were then registered to a surgical navigation system using 3 different methods. The first method uses a conventional manual registration, using the actual patient's imaging data. The second method is done by directly scanning the created model using intraoperative computed tomography followed by registering the model to a new imaging dataset manually. The third is similar to the second method of scanning the model but eventually uses an automatic registration technique. The errors for each experiment were then calculated based on the distance of the surgical navigation probe from the respective positions of the embedded marker points. RESULTS: Errors were found in the preparation and printing techniques, largely depending on the orientation of the printed segment and postprocessing, but these were relatively small. Larger errors were noted based on a couple of variables: if the models were registered using the original patient imaging data as opposed to using the imaging data from directly scanning the model (1.28 mm vs. 1.082 mm), and the accuracy was best using the automated registration techniques (0.74 mm). CONCLUSION: Spatial accuracy errors occur consistently in every 3D fabricated model. These errors are derived from the fabrication process, the image registration process, and the surgical process of registration.