Intraoperative Imaging Techniques Research Articles

Microelectrode Recording During Deep Brain Stimulation Does Not Consistently Represent Lead Trajectory.

Long-term outcomes in deep brain stimulation (DBS) depend on accuracy of lead placement. Microelectrode recording (MER) is a long-used adjunct to leverage neurophysiological information to confirm satisfactory trajectory of implanted electrodes. The goal of this study was to evaluate the consistency in which electrodes are placed in sampled microelectrode trajectories. This is a retrospective study using intraoperative computed tomography to measure final electrode deviation from MER probe placement during the DBS insertion targeting subthalamic nucleus. Fifteen patients had 29 DBS leads placed using MER assistance. Radial distance between the probe and the lead were measured for each patient using intraoperative imaging. In addition, the preoperative target to final lead error was measured in 14 patients undergoing subthalamic nucleus implants without the use of MER and compared with the 15 patients in which MER was used as an adjunct. There was no significant difference in the mean radial target error (1.2 vs 1.0 mm, P = .156) when comparing the leads placed with or without MER assistance, respectively. The mean difference in final position of microelectrode compared with DBS lead was 0.9 ± 0.1 (range 0.4-2.0 mm). Of all MER-assisted electrodes placed, 44.8% (13) of electrode final positions radially deviated 1.0 mm or more from the MER probe. Electrode placement may deviate significantly from MER trajectories. Given the concern that physiological data may not be representative of the final electrode trajectory, surgeons should consider using intraoperative imaging or other adjunctive techniques during DBS to confirm accuracy and satisfactory trajectory of DBS leads.

Sacral dysmorphism and its influence on hardware choice in sacral fractures: A scoping review

Purpose In the setting of sacral fractures, percutaneous screw fixation is a reliable, safe, and minimally invasive method for managing most stable and unstable fractures. However, significant variations in sacral anatomy due to sacral dysmorphism (SDM) could prevent safe implementation. This scoping review aimed to highlight such a detrimental yet under-reported variable in managing sacral fractures. Methods A scoping review was conducted following the Arksey and O’Malley framework for scoping studies. A comprehensive literature search of four electronic databases was conducted to identify relevant peer-reviewed studies. Data were extracted from eligible articles to summarize, collate, and create a narrative account of the findings. Results Twenty-one articles were included in our review (18 level III, two level II, and one level I). Studies were categorized into three main groups based on the investigated outcomes: prevalence and determinants of SDM, effect of SDM on the surgical corridor, and efficacy of different intra-operative imaging modalities. The prevalence of SDM ranged from 10 to 85%. The presence of SDM decreased the available surgical corridor at S1, with a compensated increase at S2 and S3. Mixed results regarding accuracy and revision rate were identified between different intra-operative imaging techniques. Conclusion SDM represents consistent yet atypical “safe zone,” sizes, and angles that require careful analysis and technique alterations when placing upper and second sacral segment screws. Considering their limited availability, high cost, and mixed results, navigated imaging systems represent a promising technique that requires more rigorous examination of its efficacy before widespread adoption.

Do Hounsfield Units From Intraoperative CT Scans Correlate With Preoperative Values?

There is increasing interest in forecasting postoperative complications using bone density metrics. Vertebral Hounsfield unit measurements obtained from CT scans performed for surgical planning or other purposes, known as opportunistic CTs, have shown promise for their ease of measurement and the ability to target density measurement to a particular region of interest. Concomitant with the rising interest in prognostic bone density measurement use has been the increasing adoption of intraoperative advanced imaging techniques. Despite the interest in both outcome prognostication and intraoperative advanced imaging, there is little information regarding the use of CT-based intraoperative imaging as a means to measure bone density. (1) Can vertebral Hounsfield units be reliably measured by physician reviewers from CT scans obtained intraoperatively? (2) Do Hounsfield units measured from intraoperative studies correlate with values measured from preoperative CT scans? To be eligible for this retrospective study, patients had to have been treated with the use of an intraoperative CT scan for instrumented spinal fusion for either degenerative conditions or traumatic injuries between January 2015 and December 2022. Importantly, patients without a preoperative CT scan of the fused levels within 180 days before surgery or who were indicated for surgery because of infection, metastatic disease, or who were having revision surgery after prior instrumentation were excluded from the query. Of the 285 patients meeting these inclusion criteria, 53% (151) were initially excluded for the following reasons: 36% (102) had intraoperative CT scans obtained after placement of instrumentation, 16% (47) had undergone intraoperative CT scans but the studies were not accessible for Hounsfield unit measurement, and 0.7% (2) had prior kyphoplasty wherein the cement prevented Hounsfield unit measurement. Finally, an additional 19% (53) of patients were excluded because the preoperative CT and intraoperative CT were obtained at different peak voltages, which can influence Hounsfield unit measurement. This yielded a final population of 81 patients from whom 276 preoperative and 276 intraoperative vertebral Hounsfield unit measurements were taken. Hounsfield unit data were abstracted from the same vertebra(e) from both preoperative and intraoperative studies by two physician reviewers (one PGY3 and one PGY5 orthopaedic surgery resident, both pursuing spine surgery fellowships). For a small, representative subset of patients, measurements were taken by both reviewers. The feasibility and reliability of Hounsfield unit measurement were then assessed with interrater reliability of values measured from the same vertebra by the two different reviewers. To compare Hounsfield unit values from intraoperative CT scans with preoperative CT studies, an intraclass correlation using a two-way random effects, absolute agreement testing technique was employed. Because the data were formatted as multiple measurements from the same vertebra at different times, a repeated measures correlation was used to assess the relationship between preoperative and intraoperative Hounsfield unit values. Finally, a linear mixed model with patients handled as a random effect was used to control for different patient and clinical factors (age, BMI, use of bone density modifying agents, American Society of Anesthesiologists [ASA] classification, smoking status, and total Charlson comorbidity index [CCI] score). We found that Hounsfield units can be reliably measured from intraoperative CT scans by human raters with good concordance. Hounsfield unit measurements of 31 vertebrae from a representative sample of 10 patients, measured by both reviewers, demonstrated a correlation value of 0.82 (95% CI 0.66 to 0.91), indicating good correlation. With regard to the relationship between preoperative and intraoperative measurements of the same vertebra, repeated measures correlation testing demonstrated no correlation between preoperative and intraoperative measurements (r = 0.01 [95% CI -0.13 to 0.15]; p = 0.84). When controlling for patient and clinical factors, we continued to observe no relationship between preoperative and intraoperative Hounsfield unit measurements. As intraoperative CT and measurement of vertebral Hounsfield units both become increasingly popular, it would be a natural extension for spine surgeons to try to extract Hounsfield unit data from intraoperative CTs. However, we found that although it is feasible to measure Hounsfield data from intraoperative CT scans, the obtained values do not have any predictable relationship with values obtained from preoperative studies, and thus, these values should not be used interchangeably. With this knowledge, future studies should explore the prognostic value of intraoperative Hounsfield unit measurements as a distinct entity from preoperative measurements. Level III, diagnostic study.

Detection and Real-Time Surgical Assessment of Colorectal Liver Metastases Using Near-Infrared Fluorescence Imaging during Laparoscopic and Robotic-Assisted Resections.

The European Association of Endoscopic Surgery (EAES) recommends, with strong evidence, the use of indocyanine green (ICG) fluorescence imaging combined with intraoperative ultrasound (IOUS) to improve identification of superficial liver tumors. This study reports the use of ICG for the detection of colorectal liver metastases (CRLMs) during minimally invasive liver resection. A single-center consecutive series of minimally invasive (laparoscopic and robotic) hepatic resections for CRLMs was prospectively evaluated (April 2019 and October 2023). A total of 25 patients were enrolled-11 undergoing laparoscopic and 14 undergoing robotic procedures. The median age was 65 (range 50-85) years. Fifty CRLMs were detected: twenty superficial, eight exophytic, seven shallow (<8 mm from the hepatic surface), and fifteen deep (>10 mm from the hepatic surface) lesions. The detection rates of CRLMs through preoperative imaging, laparoscopic ultrasound (LUS), ICG fluorescence, and combined modalities (ICG and LUS) were 88%, 90%, 68%, and 100%, respectively. ICG fluorescence staining allowed us to detect five small additional superficial lesions (not identified with other preoperative/intraoperative techniques). However, two lesions were false positive fluorescence accumulations. All rim fluorescence pattern lesions were CRLMs. ICG fluorescence was used as a real-time guide to assess surgical margins during parenchymal-sparing liver resections. All patients with integrity of the fluorescent rim around the CRLM displayed a radical resection during histopathological analysis. Four patients (8%) with a protruding rim or residual rim patterns had positive resection margins. ICG fluorescence imaging can be integrated with other conventional intraoperative imaging techniques to optimize intraoperative staging. Rim fluorescence proved to be a valid indicator of the resection margins: by removing the entire fluorescent area, a tumor-negative resection (R0) is achieved.

Intraoperative imaging techniques for robotic-assisted partial nephrectomy: where do we stand?

Robot-assisted partial nephrectomy is currently the gold standard treatment for localized selected cT1 and cT2 renal tumors. This narrative review aims to analyze the technologies employed in this procedure to increase the precision and accuracy of the surgeon, in order to obtain adequate oncological radicality, negative surgical margins, and good preservation of renal function. In this scenario, new technologies are developing, from three-dimensional reconstructions to artificial intelligence up to the new concept of metaverse.

Fluroscopy-assisted transiliac antegrade lag screw placement technique in both columns of acetabulum: A novel procedure

The use of pelvic osseous fixation corridors and lag screw fixation in acetabular and pelvic surgery has gained popularity, especially with the recent development of intraoperative imaging and navigation techniques. However, advanced intraoperative imaging and navigation techniques require technical equipment and are costly. Therefore, traditional fluoroscopic techniques still maintain their importance. In this article, we describe a novel pelvic osseous fixation corridor that traverses both columns of the acetabulum, along with the detailed methodology of its fluoroscopic imaging and the techniques for fluoroscopy-assisted screw placement. The technique of placing screws in this current fixation corridor is only under fluoroscopy assistance, without using any specially produced guide or navigation device. Level of proofIV.

Usefulness of Intraoperative Infrared Thermography in Intracranial Surgeries: Past, Present, and Future

AbstractWith the advancement of technology in Neurosurgery, imaging guidance for surgical planning and intraoperative assessment has become relevant. Currently, two major methods of imaging guidance are generally explored in the literature, namely based on imaging and fluorescence. These techniques, however, are not without limitations. Thermal imaging has potentially broad applications in clinical practice, especially for intracranial diseases. Infrared thermography (IT) has been an underestimated tool with few reports on its usefulness during intracranial surgeries. In this article, we aim to provide a brief discussion on the limitations of current intraoperative imaging techniques for intracranial surgeries and to provide an in-depth state-of-the-art review on intraoperative IT (IIT) for intracranial lesions. High-resolution IIT is a non-invasive alternative imaging method that provides real-time estimation of regional cerebral blood flow. For brain tumors, the studies were mostly directed to diagnostic purposes and occasionally for lesion-localization. The use of IIT to address the extent of resection is a potential new application. Clinical data in this issue suggests that IIT might detect residual tumors, occasionally not assessed by other imaging technologies. Thermographic measurements during vascular and epilepsy surgeries comprise an interesting field for future research with potential clinical implications. Further experimental and clinical studies should be addressed to provide technical refinements and verify the usefulness of this noninvasive technology in neurosurgery.

Self-Disassembling and Oxygen-Generating Porphyrin-Lipoprotein Nanoparticle for Targeted Glioblastoma Resection and Enhanced Photodynamic Therapy.

The dismal prognosis for glioblastoma multiform (GBM) patients is primarily attributed to the highly invasive tumor residual that remained after surgical intervention. The development of precise intraoperative imaging and postoperative residual removal techniques will facilitate the gross total elimination of GBM. Here, a self-disassembling porphyrin lipoprotein-coated calcium peroxide nanoparticles (PLCNP) is developed to target GBM via macropinocytosis, allowing for fluorescence-guided surgery of GBM and improving photodynamic treatment (PDT) of GBM residual by alleviating hypoxia. By reducing self-quenching and enhancing lysosome escape efficiency, the incorporation of calcium peroxide (CaO2) cores in PLCNP amplifies the fluorescence intensity of porphyrin-lipid. Furthermore, the CaO2 core has diminished tumor hypoxia and improves the PDT efficacy of PLCNP, enabling low-dose PDT and reversing tumor progression induced by hypoxia aggravation following PDT. Taken together, this self-disassembling and oxygen-generating porphyrin-lipoprotein nanoparticle may serve as a promising all-in-one nanotheranostic platform for guiding precise GBM excision and empowering post-operative PDT, providing a clinically applicable strategy to combat GBM in a safe and effective manner.

Cardiac dimensions and hemodynamics in healthy juvenile Landrace swine

BackgroundSwine are frequently used as animal model for cardiovascular research, especially in terms of representativity of human anatomy and physiology. Reference values for the most common species used in research are important for planning and execution of animal testing. Transesophageal echocardiography is the gold standard for intraoperative imaging, but can be technically challenging in swine. Its predecessor, epicardial echocardiography (EE), is a simple and fast intraoperative imaging technique, which allows comprehensive and goal-directed assessment. However, there are few echocardiographic studies describing echocardiographic parameters in juvenile swine, none of them using EE. Therefore, in this study, we provide a comprehensive dataset on multiple geometric and functional echocardiographic parameters, as well as basic hemodynamic parameters in swine using EE.MethodsThe data collection was performed during animal testing in ten female swine (German Landrace, 104.4 ± 13.0 kg) before left ventricular assist device implantation. Hemodynamic data was recorded continuously, before and during EE. The herein described echocardiographic measurements were acquired according to a standardized protocol, encompassing apical, left ventricular short axis and long axis as well as epiaortic windows. In total, 50 echocardiographic parameters and 10 hemodynamic parameters were assessed.ResultsEpicardial echocardiography was successfully performed in all animals, with a median screening time of 14 min (interquartile range 11–18 min). Referring to left ventricular function, ejection fraction was 51.6 ± 5.9% and 51.2 ± 6.2% using the Teichholz and Simpson methods, respectively. Calculated ventricular mass was 301.1 ± 64.0 g, as the left ventricular end-systolic and end-diastolic diameters were 35.3 ± 2.5 mm and 48.2 ± 3.5 mm, respectively. The mean heart rate was 103 ± 28 bpm, mean arterial pressure was 101 ± 20 mmHg and mean flow at the common carotid artery was 627 ± 203 mL/min.ConclusionEpicardial echocardiography allows comprehensive assessment of most common echocardiographic parameters. Compared to humans, there are important differences in swine with respect to ventricular mass, size and wall thickness, especially in the right heart. Most hemodynamic parameters were comparable between swine and humans. This data supports study planning, animal and device selection, reinforcing the three R principles in animal research.Graphical

Intraoperative Imaging Techniques in Oncology

Imaging-based procedures have become well integrated into the diagnosis and management of oncological patients and play a significant role in reducing morbidity and mortality rates. Here we describe the established and upcoming surgical oncological imaging techniques and their impact on cancer management.

Efficient Deformable Tissue Reconstruction via Orthogonal Neural Plane.

Intraoperative imaging techniques for reconstructing deformable tissues in vivo are pivotal for advanced surgical systems. Existing methods either compromise on rendering quality or are excessively computationally intensive, often demanding dozens of hours to perform, which significantly hinders their practical application. In this paper, we introduce Fast Orthogonal Plane (Forplane), a novel, efficient framework based on neural radiance fields (NeRF) for the reconstruction of deformable tissues. We conceptualize surgical procedures as 4D volumes, and break them down into static and dynamic fields comprised of orthogonal neural planes. This factorization discretizes the four-dimensional space, leading to a decreased memory usage and faster optimization. A spatiotemporal importance sampling scheme is introduced to improve performance in regions with tool occlusion as well as large motions and accelerate training. An efficient ray marching method is applied to skip sampling among empty regions, significantly improving inference speed. Forplane accommodates both binocular and monocular endoscopy videos, demonstrating its extensive applicability and flexibility. Our experiments, carried out on two in vivo datasets, the EndoNeRF and Hamlyn datasets, demonstrate the effectiveness of our framework. In all cases, Forplane substantially accelerates both the optimization process (by over 100 times) and the inference process (by over 15 times) while maintaining or even improving the quality across a variety of non-rigid deformations. This significant performance improvement promises to be a valuable asset for future intraoperative surgical applications. The code of our project is now available at https://github.com/Loping151/ForPlane.

Advances in Intraoperative Glioma Tissue Sampling and Infiltration Assessment.

Gliomas are infiltrative brain tumors that often involve functional tissue. While maximal safe resection is critical for maximizing survival, this is challenged by the difficult intraoperative discrimination between tumor-infiltrated and normal structures. Surgical expertise is essential for identifying safe margins, and while the intraoperative pathological review of frozen tissue is possible, this is a time-consuming task. Advances in intraoperative stimulation mapping have aided surgeons in identifying functional structures and, as such, has become the gold standard for this purpose. However, intraoperative margin assessment lacks a similar consensus. Nonetheless, recent advances in intraoperative imaging techniques and tissue examination methods have demonstrated promise for the accurate and efficient assessment of tumor infiltration and margin delineation within the operating room, respectively. In this review, we describe these innovative technologies that neurosurgeons should be aware of.

Possibilities of the merge technique for intraoperative imaging in a lead implantation into the cardiac conduction system for permanent cardiac pacing: interim results of the study

Introduction. A lead implantation into the cardiac conduction system (CCS) is currently the most physiological method of pacing. However, despite the availability of specialized lead and delivery systems, the proportion of non-targeted implantations is very significant. There is a need for an intraoperative visualization technique. The lead position is monitored by electrophysiological and fluoroscopic methods, which, obviously, are not enough.Aim: To optimize the implantation of leads in the conduction system of the heart through the use of intraoperative merge visualization technique (IVT).Material and methods. Two study groups are formed as part of the protocol of a prospective study. In the patients of the study group leads were implanted into the CCS using the IVT; in the control group - by traditional method. After implantation, in all patients the position of the lead using a transthoracic echocardiography (TTE), ECG was assessed. Computed tomography (CT) was performed in patients of study group before and after implantation. In patients of control group CT was performed after implantation.Results. The full study protocol was completed in 10 patients of the study group and in 10 patients of the control group. All patients of the study group confirmed the lead implantation into the interventricular septum (IVS) using TTE and CT; into the CCS using ECG. The duration of the surgery was 87.5 [70; 120] min, fluoroscopy time – 225 [125; 421] sec. Complications, non-target implantations were not registered. In the control group, the duration of the surgery was 100 [100;110] min, the time of fluoroscopy was 775 [500;1230] sec.; stimulation of the CCS was confirmed in 4 (40%) patients; recorded 2 (20%) cases of perforation of the IVS, 1 (10%) case of implantation in the area of the apical part of the right ventricle, 1 (10%) intraoperative dislocation of the right ventricular lead, 1 (10%) case of hemopericardium in the early postoperative period. The average measurement error according to the intraoperative imaging technique compared with MSCT: the distance from the LV endocardium to the lead was 0.98 ± 0.51 mm, the distance from the lead to the tricuspid valve ring was 3.1 ± 0.92 mm. According to trans-thoracic echocardiography, there weren’t structural and functional changes in the tricuspid valve, newly emerged local areas of the myocardium with impaired contractility were detected in patients of the two groups. There weren’t significant changes in sensitivity thresholds, stimulation, and postoperative dislocations of the leads.Conclusions. The use of IVT allows to reduce the number of “off-target” implantations, the time of fluoroscopy, the radiation exposure of the operator and the duration of the surgery.

Intraoperative Imaging and Optical Visualization Techniques for Brain Tumor Resection: A Narrative Review.

Advancements in intraoperative visualization and imaging techniques are increasingly central to the success and safety of brain tumor surgery, leading to transformative improvements in patient outcomes. This comprehensive review intricately describes the evolution of conventional and emerging technologies for intraoperative imaging, encompassing the surgical microscope, exoscope, Raman spectroscopy, confocal microscopy, fluorescence-guided surgery, intraoperative ultrasound, magnetic resonance imaging, and computed tomography. We detail how each of these imaging modalities contributes uniquely to the precision, safety, and efficacy of neurosurgical procedures. Despite their substantial benefits, these technologies share common challenges, including difficulties in image interpretation and steep learning curves. Looking forward, innovations in this field are poised to incorporate artificial intelligence, integrated multimodal imaging approaches, and augmented and virtual reality technologies. This rapidly evolving landscape represents fertile ground for future research and technological development, aiming to further elevate surgical precision, safety, and, most critically, patient outcomes in the management of brain tumors.

Technical nuances for the resection of cervical dumbbell schwannomas.

The majority of spinal nerve sheath tumors are within the intradural/extramedullary compartment. A subset of these tumors develop extraforaminal components that gradually expand into potential spaces. Herein, the authors provide a 2D video demonstrating the technical nuances concerning resection of cervical dumbbell schwannomas with extraspinal extension. Although nerve sheath tumors with large extraforaminal extension are often associated with complications and pose unique challenges to surgeons, circumferential exposure with intradural exploration allows for gross-total resection and nerve root preservation, without need for adjuvant treatments. The use of intraoperative ultrasound, neurophysiological monitoring, Doppler imaging, and meticulous surgical techniques aided to circumvent complications.

Care Pathway Analysis to Inform the Earliest Stages of Technology Development: Scoping Oncological Indications in Need of Innovation

ObjectivesIdentifying unmet needs for innovative solutions across disease contexts is challenging but important for directing funding and research efforts and informing early-stage decisions during the innovation process. Our aim was to study the merits of care pathway analysis to scope disease contexts and guide the development of innovative devices. We used oncologic surgery as a case study, for which many intraoperative imaging techniques are under development. MethodsCare pathway analysis is a mapping process, which produces graphical maps of clinical pathways using important outcomes and subsequent consequences. We performed care pathway analyses for glioblastoma, breast, bladder, prostate, renal, pancreatic, and oral cavity cancer. Differences between a “perfect” care pathway and the current care pathway in terms of percentage of inadequate margins, associated recurrences, quality of life, and 5-year overall survival were calculated to determine unmet needs. Data from The Netherlands Cancer Registry and literature were used. ResultsCare pathway analysis showed that highest percentages of inadequate margins were found in oral cavity cancer (72.5%), glioblastoma (48.7%), and pancreatic cancer (43.9%). Inadequate margins showed the strongest increase in recurrences in cancer of oral cavity, and bladder (absolute increases of 43.5% and 41.2%, respectively). Impact on survival was largest for bladder and oral cavity cancer with positive margins. ConclusionsCare pathway analysis provides overviews of current clinical paths in multiple indications. Disease contexts can be compared via effectiveness gaps that show the potential need for innovative solutions. This information can be used as basis for stakeholder involvement processes to prioritize care pathways in need of innovation.

P15.07.B FUNCTIONAL BRAIN MAPPING DURING AWAKE TUMOR RESECTIONS USING ESM-FMRI CO-REGISTERED FUNCTIONAL ULTRASOUND (FUS)-IMAGING

Abstract BACKGROUND Neurosurgical resection of brain tumors resembles a balancing act between maximing extent of tumor resection (efficacy) and minimizing the risk of post-operative neurological deficits (safety). Given the difficulty of this trade-off, it is surprising how limited the neurosurgeon’s intra-operative tools are. To this day, neurosurgeons still resect brain tumors without any form of real-time volumetric functional imaging. Functional Ultrasound (fUS) shows great potential as a next-generation intra-operative functional imaging technique, combining submillimeter-subsecond spatiotemporal resolution, high-depth penetration and large fields of view. In previous work we have successfully shown fUS’ ability to map out hemodynamics-based functional brain activity during language and motor tasks during awake tumor resections. However, there has been no study comparing fUS-acquired functional maps and its gold standard counterpart of BOLD-fMRI imaging or Electrocortical Stimulation Mapping (ESM). Here we present our first results of concomitant ESM-, fMRI- and fUS-imaging in the same human subjects. MATERIAL AND METHODS In N = 3 patients undergoing awake surgery for tumor removal, we performed paired functional testing with pre-operative fMRI and intra-operative fUS and ESM. Using conventional linear ultrasound arrays (GE L8-18I-D (7.8 MHz) and GE 9L-D Logiq 9 (5.3 MHz)) interfaced with our experimental system (Vantage-256, Verasonics), we could acquire fUS-images up to 8 cm in depth with a PRF up to 800 Hz. Building on clinically available neuro-navigation software with optical tracking (Brainlab), we co-registered our intra-operative fUS-maps and ESM-hotspots to pre-operative MRI/CT-data in real-time to study spatiotemporal overlap. RESULTS In motor, language and visual tasks, we were able to demonstrate consistent spatial overlap between the fUS-based and ESM- and fMRI-based functional regions. Our fUS functional maps presented with unprecedented mesoscopic-scale precision (400 µm), even at depths of over &amp;gt; 5 cm. In contrast to fMRI and ESM, fUS was also able to concomitantly visualize the in-vivo microvascular morphology underlying the functional hemodynamics. The current results were only obtainable after we developed a powerful study pipeline including pre-operative fMRI-imaging and ROI-planning, intra-operative integration of experimental Doppler-data and co-registered functional analyses. CONCLUSION The work presented here is the first-ever, in-human comparison between ESM-, fMRI- and fUS-based functional data, serving as a significant milestone towards further clinical maturity of fUS as a new intra-operative tool to improve the safety and efficacy of neurosurgical brain tumor resections. Disclosure: This work was supported by the NWO-Groot grant of The Dutch Organization for Scientific Research (NWO) (Grant no. 108845).

Use of Near-Infrared Fluorescence Techniques in Minimally Invasive Surgery for Colorectal Liver Metastases.

Colorectal liver metastases (CRLM) afflict a significant proportion of patients with colorectal cancer (CRC), ranging from 25% to 30% of patients throughout the course of the disease. In recent years, there has been a surge of interest in the application of near-infrared fluorescence (NIRF) imaging as an intraoperative imaging technique for liver surgery. The utilisation of NIRF-guided liver surgery, facilitated by the administration of fluorescent dye indocyanine green (ICG), has gained traction in numerous medical institutions worldwide. This innovative approach aims to enhance lesion differentiation and provide valuable guidance for surgical margins. The use of ICG, particularly in minimally invasive surgery, has the potential to improve lesion detection rates, increase the likelihood of achieving R0 resection, and enable anatomically guided resections. However, it is important to acknowledge the limitations of ICG, such as its low specificity. Consequently, there has been a growing demand for the development of tumour-specific fluorescent probes and the advancement of camera systems, which are expected to address these concerns and further refine the accuracy and reliability of intraoperative fluorescence imaging in liver surgery. While NIRF imaging has been extensively studied in patients with CRLM, it is worth noting that a significant proportion of published research has predominantly focused on the detection of hepatocellular carcinoma (HCC). In this study, we present a comprehensive literature review of the existing literature pertaining to intraoperative fluorescence imaging in minimally invasive surgery for CRLM. Moreover, our analysis places specific emphasis on the techniques employed in liver resection using ICG, with a focus on tumour detection in minimal invasive surgery (MIS). Additionally, we delve into recent developments in this field and offer insights into future perspectives for further advancements.

Renal perfusion improvement in the perioperative period after unilateral endovascular revascularization in patients with atherosclerotic renal artery stenosis.

The clinical benefits of endovascular treatment in renal artery stenosis (RAS) remain controversial. This study used an intraoperative renal perfusion imaging technique, called flat-panel detector parenchymal blood volume imaging (FD-PBV), to observe the change in renal perfusion after endovascular treatment in RAS. In a prospective, single-center study, we assigned 30 patients with atherosclerotic RAS who underwent endovascular treatment between March 2016 and March 2021. The preoperative and postoperative results of renal perfusion, blood pressure, and renal function, were compared. Both median kidney volume (p < 0.001) and median preoperative mean density of contrast medium (MDCM) (p = 0.028) increased significantly after endovascular treatment. The ratio of postoperative and preoperative MDCM differed greatly among the patients. For patients with preoperative MDCM <304.0 HU (Subgroup A, 15 cases), MDCM significantly increased after treatment (p = 0.001) and 12 (80.0%) patients had more than 10% increase in renal perfusion. For patients who had relatively high preoperative renal perfusion (MDCM ≥304.0 HU, Subgroup B, 15 cases), preoperative and postoperative MDCM were similar (p = 0.776). On the other hand, the serum creatinine levels significantly decreased in Subgroup A (p = 0.033) and fewer antihypertensive drugs were used after endovascular revascularization (p = 0.041). The preoperative and postoperative creatinine levels and number of antihypertensive drugs were similar in Subgroup B. During the perioperative period, RAS patients with relatively low preoperative renal perfusion levels had greater improvement in renal perfusion, renal function, and blood pressure control after endovascular treatment. The improvement of renal function needs to be confirmed by long-term follow-up.

Endoscopic Transoral Odontoidectomy of Craniovertebral Junction Rheumatoid Arthritis With the Help of Real-Time Fluoroscopy and Intraoperative Computed Tomography.

Rheumatoid arthritis (RA) involvement in the craniovertebral junction (CVJ) is a rare condition after antirheumatoid medications, nevertheless still exists. Neurological deterioration of the patient makes surgery inevitable. Seventy-seven years old man without antirheumatoid treatment presented with progressive neurological deterioration and CVJ involvement of RA with severe cord compression with myelomalacia. The patient underwent endoscopic transoral odontoidectomy with real-time fluoroscopy and intraoperative computed tomography. Even though radiological improvement has been achieved the patient died because of pulmonary complications. Rheumatoid arthritis of CVJ is a life-threatening medical condition. Surgical procedures will be safer by using endoscopy and intraoperative radiological imaging techniques.