Intraoperative Recordings Research Articles

A comparison between real-time intraoperative voice dictation and the operative report in laparoscopic cholecystectomy: a multicenter prospective observational study

PurposeThe current operative report often inadequately reflects events occurring during laparoscopic cholecystectomy (LC). The addition of intraoperative video recording to the operative report has already proven to add important information. It was hypothesized that real-time intraoperative voice dictation (RIVD) can provide an equal or more complete overview of the operative procedure compared to the narrative operative report (NR) produced postoperatively.MethodsSONAR is a multicenter prospective observational trial, conducted at four surgical centers in the Netherlands. Elective LCs of patients aged 18 years and older were included. Participating surgeons were requested to dictate the essential steps of LC during surgery. RIVDs and NRs were reviewed according to the stepwise LC guideline of the Dutch Society for Surgery. The cumulative adequacy rates for RIVDs were compared with those of the postoperatively written NR.Results79 of 90 cases were eligible for inclusion and available for further analysis. RIVD resulted in a significantly higher adequacy rate compared to NR for the circumferential dissection of the cystic duct and artery (NR 32.5% vs. RIVD 61.0%, P = 0.016). NR had higher adequacy rates in reporting the transection of the cystic duct (NR 100% vs. RIVD 77.9%, P = < 0.001) and the removal of the gallbladder from the liver bed (NR 98.7% vs. RIVD 68.8%, P < 0.001). The total adequacy was not significantly different between the two reporting methods (NR 78.0% vs. RIVD 76.4%, P = 1.00).ConclusionOverall, the adequacy of RIVD is comparable to the postoperatively written NR in reporting surgical steps in LC. However, the most essential surgical step, the circumferential dissection of the cystic duct and artery, was reported more adequately in RIVD.

Combination of deep learning and ensemble machine learning using intraoperative video images strongly predicts recovery of urinary continence after robot-assisted radical prostatectomy.

We recently reported the importance of deep learning (DL) of pelvic magnetic resonance imaging in predicting the degree of urinary incontinence (UI) following robot-assisted radical prostatectomy (RARP). However, our results were limited because the prediction accuracy was approximately 70%. To develop a more precise prediction model that can inform patients about UI recovery post-RARP surgery using a DL model based on intraoperative video images. The study cohort comprised of 101 patients with localized prostate cancer undergoing RARP. Three snapshots from intraoperative video recordings showing the pelvic cavity (prior to bladder neck incision, immediately following prostate removal, and after vesicourethral anastomosis) were evaluated, including pre- and intraoperative parameters. We evaluated the DL model plus simple or ensemble machine learning (ML), and the area under the receiver operating characteristic curve (AUC) was analyzed through sensitivity and specificity. Of 101, 64 and 37 patients demonstrated "early continence (using 0 or 1 safety pad at 3 months post-RARP)" and "late continence (others)," respectively, at 3 months postoperatively. The combination of DL and simple ML using intraoperative video snapshots with clinicopathological parameters had a notably high performance (AUC, 0.683-0.749) to predict early recovery from UI after surgery. Furthermore, combining DL with ensemble artificial neural network using intraoperative video snapshots had the highest performance (AUC, 0.882; sensitivity, 92.2%; specificity, 78.4%; overall accuracy, 85.3%) to predict early recovery from post-RARP incontinence, with similar results by internal validation. The addition of clinicopathological parameters showed no additive effects for each analysis using DL, EL and simple ML. Our findings suggest that the DL algorithm with intraoperative video imaging is a reliable method for informing patients about the severity of their recovery from UI after RARP, although it is not clear if our methods are reproducible for predicting long-term UI and pad-free continence.

Functional network dynamics between the anterior thalamus and the cortex in deep brain stimulation for epilepsy.

Due to its unique connectivity profile with cortical brain regions, and its suggested role in the subcortical propagation of seizures, the Anterior Nucleus of the Thalamus (ANT) has been proposed as a key Deep Brain Stimulation (DBS) target in drug-resistant epilepsy (DRE). However, the spatio-temporal interaction dynamics of this brain structure, and the functional mechanisms underlying ANT DBS in epilepsy, remain unknown. Here, we study how the ANT interacts with the neocortex in vivo in humans and provide a detailed neurofunctional characterization of mechanisms underlying the effectiveness of ANT DBS, aiming at defining intraoperative neural biomarkers of responsiveness to therapy, assessed at 6 months post-implantation as the reduction in seizure frequency. A cohort of 15 DRE (N = 6 males, age = ) patients underwent bilateral ANT DBS implantation. Using intraoperative cortical and ANT simultaneous electrophysiological recordings, we found that the ANT is characterized by high amplitude (4-8 Hz) oscillations, mostly in its superior part. The strongest functional connectivity between the ANT and the scalp EEG was also found in the band in ipsilateral centro-frontal regions. Upon intraoperative stimulation in the ANT, we found a decrease in higher EEG frequencies (20-70 Hz) and a generalized increase in scalp-to-scalp connectivity. Crucially, we observed that responders to ANT DBS treatment were characterized by higher EEG oscillations, higher power in the ANT, and stronger ANT-to-scalp θ connectivity, highlighting the crucial role of oscillations in the dynamical network characterization of these structures. Our study provides a comprehensive characterization of the interaction dynamic between the ANT and the cortex, delivering crucial information to optimize and predict clinical DBS response in patients with DRE.

Associations among anesthesia-induced brain biomarkers during surgery, preoperative exposure to cancer therapeutics, and clinical outcomes.

12095 Background: Cognitive impairment represents a key concern in oncology, as issues with memory and concentration can be a debilitating side effect of cancer and its treatment. Prior work demonstrates that the power of the alpha wave, a pattern of electroencephalographic (EEG) signals in the brain in patients under general anesthesia, correlates with cognitive function. In this study, we sought to investigate the associations among anesthesia-induced alpha power, preoperative exposure to cancer therapeutics, and clinical outcomes in a large cohort of patients undergoing surgery. Methods: We analyzed intra-operative EEG recordings of a retrospective cohort of patients with and without cancer who underwent surgery with general anesthesia at a single institution between 4/2016 - 12/2019. We used multivariable regression models (adjusted for age, sex, history of dementia) to determine associations of cancer-related covariates with patients’ alpha power (measured in decibels [dB]), and to determine associations of alpha power with clinical outcomes, such as hospital length of stay, discharge location, hospital readmission, and survival. Results: Among 1,084 total patients included in this study, 377 (35%) had a preoperative diagnosis of cancer. The most common cancer diagnoses were breast (87, 23% of those with cancer), gastrointestinal (85, 23%), genitourinary (73, 19%), and lung (47, 12%). We found that a cancer diagnosis alone was not associated with alpha power (-0.015 dB, p = 0.95). However, among patients with cancer, receiving chemotherapy within 3 months before surgery was associated with a 1.6dB drop in alpha power (p &lt; 0.001). By comparison, having a preoperative diagnosis of dementia was associated with a drop of 2.86dB (p &lt; 0.001). Decreased alpha power was associated with longer hospital stays (1.03 times longer per dB drop, p &lt; 0.001), higher rates of discharge to a rehab facility (odds ratio [OR] = 1.22 per dB drop, p &lt; 0.001), and higher mortality (hazard ratio = 1.085 per dB drop, p &lt; 0.001). We found no association between alpha power and 30-day readmission (OR = 1.04, p = 0.24). Conclusions: In this large cohort of patients undergoing surgery, we found that alpha power correlated with several important clinical outcomes, and that recent receipt of chemotherapy was associated with a decrease in alpha power. Of note, the observed drop of 1.6 dB among those with recent chemotherapy is roughly equivalent to aging 10-15 years, while a diagnosis of dementia was associated with a nearly 3dB drop in alpha power. As evidence suggests that alpha power corresponds with patients’ cognitive function, our findings highlight the need to prospectively monitor and track longitudinal alpha power in patients receiving cancer treatment to determine if early detection of changes in alpha power may predict for future treatment-related cognitive decline.

Proposal of a Full Digital Workflow for a Bite Fork to Assess Mandibular Advancement during Drug-Induced Sleep Endoscopy (DISE) for Obstructive Sleep Apnea

(1) Background. Drug-induced sleep endoscopy (DISE) is currently regarded as the gold standard diagnostic procedure to assess the site(s) of upper airway collapse in subjects affected by Obstructive Sleep Apnea Syndrome (OSAS). During DISE, a jaw thrust maneuver is performed to advance the mandible and to predict the effectiveness of outcomes of treatment with mandibular advancement devices (MADs). However, the maneuver is not predictable and could be influenced by specific patients’ anatomical/functional conditions. The aim of this work is to propose a full-digital workflow for customizing an individual mandibular advancement fork, usable by otorhinolaryngologists during DISE. (2) Materials. Two patients with a diagnosis of mild-to-moderate OSAS (AHI ≥ 5 to ≤30/h of sleep) underwent orthodontic examination to verify the usability of the MAD. Intra-oral scans and registration were performed, including bite registration with 65% of mandibular advancement. The latter measurement was used as a reference to design a 3D-printed fork for DISE, as well as for the future MAD. Both patients underwent DISE in the operating room in the presence of an anesthesiologist, otolaryngologist, orthodontic specialist and neurophysiopathology technician. (3) Results. In the intraoperative polysomnography recording, during sleep, the presence of obstructive apnea was confirmed based on respiratory parameters (PNG1, PNG2, PNG3) with associated desaturation and increased muscle activities on PNG4 (mylohyoid muscle), EMG1 (right masseter muscle) and EMG2 (left masseter muscle). With the advancement fork in place, the immediate improvement effect on all respiratory parameters with normal saturation values and the complete suppression of masseter muscles were observed. Accordingly, both patients were considered potential good-responders to the MAD treatment. (4) Conclusions. The preliminary data shown are encouraging and would suggest that the fork represents a stable reference for the otorhinolaryngologist to evaluate the airway patency within the physiological range of movement. The efficiency of the work-flow from data registration to the DISE procedure and laboratory process represent two significant advantages that justify the integration of a digital system in the management of patients affected by OSAS.

Augmented reality presentation of the extracranial facial nerve: an innovation in parotid surgery

Surgeons used to be unaware of the facial nerve's position during parotid surgery. Now, with special magnetic resonance imaging (MRI) sequences, it can be located and converted into a 3D model displayed on an augmented reality (AR) device for surgeons to study and manipulate. This study explores the accuracy and usefulness of the technique for the treatment of benign and malignant parotid tumours. A total of 20 patients with parotid tumours had 3-Tesla MRI scans, and their anatomical structures were segmented using Slicer software. The structures were imported into a Microsoft HoloLens 2® device, displayed in 3D, and shown to the patient for consent. Intraoperative video recording was used to record the position of the facial nerve in relation to the tumour. The predicted path of the nerve taken from the 3D model was combined with surgical observation and video recording in all cases. The imaging proved to have application in both benign and malignant disease. It also improved the process of informed patient consent. Three-dimensional MRI imaging of the facial nerve within the parotid gland and its display in a 3D model is an innovative technique for parotid surgery. Surgeons can now see the nerve's position and tailor their approach to each patient's tumour, providing personalised care. The technique eliminates the surgeon's blind spot and is a significant advantage in parotid surgery.

Intraoperative electrophysiological monitoring determines the final electrode position for pallidal stimulation in dystonia patients.

Bilateral deep brain stimulation (DBS) of the globus pallidus internus (GPi) is an effective treatment for refractory dystonia. Neuroradiological target and stimulation electrode trajectory planning with intraoperative microelectrode recordings (MER) and stimulation are used. With improving neuroradiological techniques, the need for MER is in dispute mainly because of the suspected risk of hemorrhage and the impact on clinical post DBS outcome. The aim of the study is to compare the preplanned GPi electrode trajectories with final trajectories selected for electrode implantation after electrophysiological monitoring and to discuss the factors potentially responsible for differences between preplanned and final trajectories. Finally, the potential association between the final trajectory selected for electrode implantation and clinical outcome will be analyzed. Forty patients underwent bilateral GPi DBS (right-sided implants first) for refractory dystonia. The relationship between preplanned and final trajectories (MicroDrive system) was correlated with patient (gender, age, dystonia type and duration) and surgery characteristics (anesthesia type, postoperative pneumocephalus) and clinical outcome measured using CGI (Clinical Global Impression parameter). The correlation between the preplanned and final trajectories together with CGI was compared between patients 1-20 and 21-40 for the learning curve effect. The trajectory selected for definitive electrode implantation matched the preplanned trajectory in 72.5% and 70% on the right and left side respectively; 55% had bilateral definitive electrodes implanted along the preplanned trajectories. Statistical analysis did not confirm any of the studied factors as predictor of the difference between the preplanned and final trajectories. Also no association between CGI and final trajectory selected for electrode implantation in the right/left hemisphere has been proven. The percentages of final electrodes implanted along the preplanned trajectory (the correlation between anatomical planning and intraoperative electrophysiology results) did not differ between patients 1-20 and 21-40. Similarly, there were no statistically significant differences in CGI (clinical outcome) between patients 1-20 and 21-40. The final trajectory selected after electrophysiological study differed from the preplanned trajectory in a significant percentage of patients. No predictor of this difference was identified. The anatomo-electrophysiological difference was not predictive of the clinical outcome (as measured using CGI parameter).

Evaluation of intraoperative coronal alignment using a computer-assisted rod bending system (CARBS) without intraoperative radiation exposure in adult spinal deformity surgery: a technical note and preliminary results.

Intraoperative radiographs and fluoroscopy are used in adult spinal deformity (ASD) surgery to prevent postoperative coronal malalignment but with limited accuracy. Therefore, we applied a computer-assisted rod bending system (CARBS: Bendini®) for an intraoperative coronal alignment evaluation. The purpose of this study is to introduce this novel technique and validate its accuracy. Fifteen ASD patients were included in the study. The heads of the bilateral S1 pedicle screws (S1), the S1 spinous process, and the bilateral greater trochanter (GT) and the C7 spinous process were recorded with CARBS for an intraoperative coronal alignment evaluation. The lines which connect the bilateral S1 and GT were used as references. The C7-center sacral vertical line (C7-CSVL) on the CARBS monitor was checked, and the C7-CSVL from the intraoperative CARBS recording and postoperative standing whole spine radiograph were compared. Intraoperative C7-CSVL with CARBS was 35.1 ± 31.6mm when the S1 pedicle screws were used as the reference line and was 16.6 ± 17.8mm when the GTs were used. Postoperative C7-CSVL by radiograph was 15.1 ± 16.5mm. In addition, the intraoperative C7-CSVL with CARBS and the postoperative C7-CSVL showed a strong positive correlation in both GT (R = 0.86, p < 0.01) and in S1(R = 0.79, p < 0.01), with a better correlation found in GT than in S1. Intraoperative C7-CSVL with CARBS was found to be highly accurate in ASD surgery. Our results suggest that this novel technique can be useful as an alternative to intraoperative radiography and fluoroscopy and may reduce radiation exposure.

Flexible, high-resolution cortical arrays with large coverage capture microscale high-frequency oscillations in patients with epilepsy.

Effective surgical treatment of drug-resistant epilepsy depends on accurate localization of the epileptogenic zone (EZ). High-frequency oscillations (HFOs) are potential biomarkers of the EZ. Previous research has shown that HFOs often occur within submillimeter areas of brain tissue and that the coarse spatial sampling of clinical intracranial electrode arrays may limit the accurate capture of HFO activity. In this study, we sought to characterize microscale HFO activity captured on thin, flexible microelectrocorticographic (μECoG) arrays, which provide high spatial resolution over large cortical surface areas. We used novel liquid crystal polymer thin-film μECoG arrays (.76-1.72-mm intercontact spacing) to capture HFOs in eight intraoperative recordings from seven patients with epilepsy. We identified ripple (80-250 Hz) and fast ripple (250-600 Hz) HFOs using a common energy thresholding detection algorithm along with two stages of artifact rejection. We visualized microscale subregions of HFO activity using spatial maps of HFO rate, signal-to-noise ratio, and mean peak frequency. We quantified the spatial extent of HFO events by measuring covariance between detected HFOs and surrounding activity. We also compared HFO detection rates on microcontacts to simulated macrocontacts by spatially averaging data. We found visually delineable subregions of elevated HFO activity within each μECoG recording. Forty-seven percent of HFOs occurred on single 200-μm-diameter recording contacts, with minimal high-frequency activity on surrounding contacts. Other HFO events occurred across multiple contacts simultaneously, with covarying activity most often limited to a .95-mm radius. Through spatial averaging, we estimated that macrocontacts with 2-3-mm diameter would only capture 44% of the HFOs detected in our μECoG recordings. These results demonstrate that thin-film microcontact surface arrays with both highresolution and large coverage accurately capture microscale HFO activity and may improve the utility of HFOs to localize the EZ for treatment of drug-resistant epilepsy.

Choice of anaesthesia in microelectrode recording-guided deep-brain stimulation for Parkinson’s disease (CHAMPION): study protocol for a single-centre, open-label, non-inferiority randomised controlled trial

IntroductionDeep brain stimulation (DBS) implantation under general anaesthesia (GA) has been applied to patients with Parkinson’s disease (PD) with severe comorbidities or disabling off-medication symptoms. However, general anaesthetics may affect...

Human acute microelectrode array recordings with broad cortical access, single-unit resolution, and parallel behavioral monitoring

There are vast gaps in our understanding of the organization and operation of the human nervous system at the level of individual neurons and their networks. Here, we report reliable and robust acute multichannel recordings using planar microelectrode arrays (MEAs) implanted intracortically in awake brain surgery with open craniotomies that grant access to large parts of the cortical hemisphere. We obtained high-quality extracellular neuronal activity at the microcircuit, local field potential level and at the cellular, single-unit level. Recording from the parietal association cortex, a region rarely explored in human single-unit studies, we demonstrate applications on these complementary spatial scales and describe traveling waves of oscillatory activity as well as single-neuron and neuronal population responses during numerical cognition, including operations with uniquely human number symbols. Intraoperative MEA recordings are practicable and can be scaled up to explore cellular and microcircuit mechanisms of a wide range of human brain functions.

Utilization of intraoperative Subthalamic Nucleus local field potential recordings to guide postoperative Deep Brain Stimulation programming in Parkinson’s disease (P5-11.013)

<h3>Objective:</h3> To investigate whether intraoperative recordings of subthalamic nucleus (STN) local field potentials (LFPs) during awake deep brain stimulation (DBS) surgery for Parkinson’s disease can provide valuable information for postoperative DBS programming. <h3>Background:</h3> DBS is a well-established treatment of Parkinson’s disease. Intraoperative LFP recordings during awake DBS surgery are used to confirm accurate targeting. Postoperative DBS programming is usually based on clinical response. It is unclear whether the intraoperative LFP recordings can guide postoperative DBS programming. <h3>Design/Methods:</h3> All patients with Parkinson’s disease who had awake placement of STN DBS electrodes with intraoperative STN LFP recordings (Alpha Omega LeadConfirm®) at the University of Utah since August 2021 were identified. The peak beta band power for each individual electrode contact was identified. For directional electrodes, the LFP beta peaks were averaged across the three directional contacts for each level. Postoperatively the DBS systems were programmed based on symptom response. The activated DBS levels were compared to the levels with the highest and lowest LFP beta band peaks. <h3>Results:</h3> 13 DBS STN electrodes, from 8 patients (all males, mean age=60±10 years, mean UPDRS score=40±14) were analyzed. The grand average peak beta band frequency was 21Hz with power of 2.3. In 2 out of 13 electrodes the level with the highest beta band peak was activated postoperatively. In 8 electrodes the active levels and the levels with the highest peaks were adjacent. In one electrode the contact with the highest peaks provided best benefit but the contact with the lowest beta peak was activated to avoid dyskinesias. <h3>Conclusions:</h3> In the majority of the electrodes (11 out of 13 electrodes) the levels that were post-operatively activated based on best clinical response coincided or were adjacent to the levels with the highest intraoperative STN LFP beta power peaks. The intraoperative LFP recordings can potentially provide valuable information for programming guidance postoperatively. <b>Disclosure:</b> An immediate family member of Dr. Anwer has received personal compensation for serving as an employee of Southwest Airlines. Dr. Anwer has stock in Boeing. Mr. PAXTON has nothing to disclose. Dr. Rahimpour has nothing to disclose. Dr. Alshaikh has nothing to disclose. D. James Ballard has nothing to disclose. Dr. Steffens has nothing to disclose. Ms. Zorn has nothing to disclose. Dr. Kassavetis has nothing to disclose.

Motor Function and Quality of Life Improvement following Asleep versus Awake Deep Brain Stimulation (DBS) Procedures (P4-11.009)

<h3>Objective:</h3> To compare real-world outcomes in patients with Parkinson’s disease (PD) whose Deep Brain Stimulation (DBS) leads were implanted using asleep procedures versus those patients that underwent the procedure using awake conditions. <h3>Background:</h3> DBS procedures are typically conducted with patients being awake to allow for intraoperative clinical testing and/or micro-electrode recording to confirm lead location. However, asleep DBS procedures (i.e., under general anesthesia) are becoming increasingly popular due, at least in part, to technological improvements in imaging allowing alternative lead placement confirmation and shorter procedure duration (Brodsky 2017, Chen 2018, Vinke 2022). <h3>Design/Methods:</h3> A sub-analysis of patients receiving their DBS lead implant under asleep versus awake conditions was conducted in an ongoing, large, multicenter, prospective real-world outcomes study (Vercise, Boston Scientific). Motor function (MDS-UDPRS III), quality of life (PDQ-39) and related outcomes (GIC) were collected at baseline and up to 3-years. Safety events were also collected. <h3>Results:</h3> To date, 157 patients (mean age 61.2±8.3 years; 69% male) were asleep and 433 (mean age 60.1±8.5 years; 66% male) were awake during lead placement. Patients in both groups presented with similar baseline age, duration of disease and disease state. Improvement in quality-of-life was noted in both groups with a 5.3-point improvement (n = 104) in asleep group and a 4.5-point improvement (n = 319) in awake group at 1-year. Similarly, an 18.8- and 20.9-point improvement in motor function was noted in the asleep and awake groups, respectively. <h3>Conclusions:</h3> Outcomes from this large dataset of real-world outcomes examining the outcomes following asleep versus awake DBS demonstrate an alignment with results from previous studies (Holewijn 2021; LaHue 2017). Patient outcomes show little to no difference between awake versus asleep groups. Sleep DBS procedures may offer potential for shortening the total time taken for DBS procedures and offer a viable alternative for patients. <b>Disclosure:</b> Jan Vesper has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Boston Scientific . Jan Vesper has received personal compensation in the range of $5,000-$9,999 for serving as a Consultant for Medtronic . Jan Vesper has received personal compensation in the range of $10,000-$49,999 for serving as a Consultant for Abbott . Jan Vesper has received personal compensation in the range of $10,000-$49,999 for serving on a Speakers Bureau for Abbott . Jan Vesper has received research support from German Research Council. Dr. Deuschl has received personal compensation in the range of $5,000-$9,999 for serving on a Scientific Advisory or Data Safety Monitoring board for Boston Scientific Cavion Functional Neuromodulation. The institution of Dr. Deuschl has received research support from Medtronic. Dr. Deuschl has received publishing royalties from a publication relating to health care. Lilly Chen has received personal compensation for serving as an employee of Boston Scientific . Roshini Jain has received personal compensation for serving as an employee of Boston Scientific. Roshini Jain has received stock or an ownership interest from Boston Scientific.

Ischemic Changes in Carotid Endarterectomies are More Severe in Left-Sided Procedures (P11-5.017)

<h3>Objective:</h3> During carotid endarterectomy (CEA), continuous monitoring with electroencephalography (EEG) is routinely used to monitor for cerebral ischemia. We studied the differences in severity of ischemic changes in the EEG between left and right CEA. <h3>Background:</h3> Prior studies have concluded that ischemic strokes are more common in the left hemisphere than in the right, and carotid atherosclerotic plaques are larger and more likely to bleed on the left side. This asymmetry may be due to anatomical differences, as the left carotid artery originates directly from the aorta, is larger, and experiences higher pressures than the right carotid artery. <h3>Design/Methods:</h3> We obtained intraoperative EEG recordings on 88 patients who underwent CEA from 2009 to 2017 and in whom clinically significant ischemic changes were observed on the EEG by visual analysis. All EEG recordings captured eight channels: F3-P3, P3-O1, F3-T3, T3-O1, F4-P4, P4-O2, F4-T4, and T4-O2. For each patient, a Fast Fourier Transform was applied to obtain the power of the alpha band (8–12 Hz) for a 10-minute post-clamp segment when most ischemic changes are observed. We statistically compared the decrease in alpha power in the ipsilateral channels between left and right CEA. <h3>Results:</h3> In the immediate 10-minute duration after the carotid artery clamping, the mean decrease in power in the alpha band in the ipsilateral channels was statistically significantly higher in left CEA compared to right CEA (t-statistic = 3.657, p-value = 0.0002). <h3>Conclusions:</h3> We speculate that left CEA produces more pronounced cerebral ischemia when the carotid artery is clamped. However, we examined only the alpha band, which is typically the band where ischemic changes are often seen, and other frequency bands should be studied in the future. Further, postsurgical outcomes should be studied to determine if intraoperative differences affect outcomes. <b>Disclosure:</b> Mr. Mina has received intellectual property interests from a discovery or technology relating to health care. Ms. Du has nothing to disclose. Mr. Pedapati has nothing to disclose. Dr. Bradley has nothing to disclose. Dr. Espino has stock in General Biodefense. Dr. Espino has stock in READE.ai. Dr. Espino has received intellectual property interests from a discovery or technology relating to health care. Dr. Batmanghelich has nothing to disclose. The institution of Dr. Thirumala has received research support from University of Pittsburgh. The institution of Dr. Visweswaran has received research support from NIH.

The Effect of Aging on Auditory Nerve Function: Insights from Intraoperative eCAP Recordings in Cochlear Implant Users.

Advanced age is associated with poorer speech perception outcomes in cochlear implant (CI) users. In an effort to improve our understanding of the basis for this decline, this study focused on the contributions from peripheral auditory processing, using the electrically evoked compound action potential (eCAP). To investigate the effect of aging on intraoperative, suprathreshold eCAP responses (amplitude growth function [AGF] slopes, eCAP maximum amplitudes, and N1 latencies) across the electrode array, in a large cohort of recipients of newer generation devices, who met hearing preservation criteria. Participants of this retrospective study consisted of 113 middle-aged and older CI recipients. Intraoperative eCAP measures consisted of AGF slopes, maximum amplitudes, and N1 latencies at the maximum amplitude. eCAP recordings were obtained at several intracochlear electrodes, which were grouped by electrode location (basal, middle, and apical). There was a moderate to strong association between suprathreshold eCAP measures (eCAP AGF slopes and maximum amplitudes) and age, particularly for basal and middle electrodes. For apical electrodes, correlations between both suprathreshold eCAP measures and age were weak (and for eCAP maximum amplitudes, not statistically significant). N1 latencies at the maximum amplitudes were not associated with age at any electrode location. Results of this study add to a growing body of evidence suggesting that aging may negatively affect suprathreshold eCAP responses, especially in basal and middle cochlear regions. Although it is difficult to separate the effects of aging from those of duration of deafness, both would support recommending early implantation in the clinical setting.

154 Comparison of Chronic and Intraoperative LFP and ECoG Recordings in Humans With Parkinson’s Disease

INTRODUCTION: Advances in implantable neurotechnologies have enabled chronic invasive long-term recordings of field potentials from depth leads or paddle-type electrocorticography (ECoG) leads. The relationship between these long-term recordings and those obtained acutely in the operating room has not been studied. METHODS: Human subjects (n=6) with movement disorders (Parkinson’s disease, dystonia) were permanently implanted with quadripolar DBS leads, and quadripolar ECoG leads over primary motor and sensory cortices, attached to a Medtronic Summit RC+S investigational device in the chest. Recordings were acquired intraoperatively using a NeuroOmega (Alpha Omega, Inc) recording system customized for research use. RC+S recordings were acquired between 1 and 345 days post implantation. The same processing pipeline was applied to both data sets, and average power spectra in canonical frequency bands (delta, theta, alpha, beta, gamma) were compared using rank sum tests within each subject. RESULTS: Power spectra show similar power law scaling phenomena between intraoperative and chronic recordings. Disease specific frequency band characteristics such as beta peaks could be seen in both chronic and intraoperative recordings, however, within subjects these were not always consistently seen. CONCLUSIONS: We present within-patient comparisons of signal characteristics (power spectra) of intraoperative recordings from a research grade recording system, with wirelessly streamed data from a chronic implantable device, using the same brain leads. Power spectra have similar characteristics between the intraoperative and long term recordings, however, there are distinct differences between the intraoperative and longer term clinic recordings, reinforcing the utility of tracking neural signals over time after the effects of lead insertion on the motor circuit have diminished.

V05-12 ANTERIOR RETROPERITONEAL APPROACH TO THE SINGLE PORT PARTIAL NEPHRECTOMY

You have accessJournal of UrologyCME1 Apr 2023V05-12 ANTERIOR RETROPERITONEAL APPROACH TO THE SINGLE PORT PARTIAL NEPHRECTOMY Grace Chen and Simone Crivellaro Grace ChenGrace Chen More articles by this author and Simone CrivellaroSimone Crivellaro More articles by this author View All Author Informationhttps://doi.org/10.1097/JU.0000000000003263.12AboutPDF ToolsAdd to favoritesDownload CitationsTrack CitationsPermissionsReprints ShareFacebookLinked InTwitterEmail Abstract INTRODUCTION AND OBJECTIVE: Since the Food and Drug Administration’s (FDA) approval of the da Vinci Single-Port (SP) robotic platform in 2018, a wealth of new surgical techniques have been described that capitalize on the SP platform’s proficiency in small spaces. A rarely described technique even among robotic surgeons is the anterior retroperitoneal approach. To our knowledge, this is the first description of this approach utilizing the SP platform in the literature. Our objective is to describe the technique used at our institution for the anterior retroperitoneal single port partial nephrectomy. METHODS: This video abstract uses intraoperative recordings from one patient who underwent a SP partial nephrectomy at our institution. The clinical techniques are described in detail following detailed discussion with an experience robotic surgeon (SC). No pathologic or short-term outcomes were available. RESULTS: Retroperitoneal access was successfully obtained via an anterior incision for a 3.7 cm interpolar mass. The mass was successfully treated without need for conversion to multi-port or open approaches. Total operative time was 192 minutes. Total estimated blood loss (EBL) was 20 cc. The total hospital length of stay (LOS) was 8 hours. The patient was successfully discharged home with a non-narcotic pain control plan. CONCLUSIONS: The anterior retroperitoneal approach to SP robotic partial nephrectomy is safe and feasible. Theoretical advantages of this approach include increased efficiency and decreased positional injuries due to the ability to perform surgery in the supine position, less bowel manipulation, and potentially decreased opioid requirements. Further outcomes data is anticipated. Source of Funding: None © 2023 by American Urological Association Education and Research, Inc.FiguresReferencesRelatedDetails Volume 209Issue Supplement 4April 2023Page: e428 Advertisement Copyright & Permissions© 2023 by American Urological Association Education and Research, Inc.MetricsAuthor Information Grace Chen More articles by this author Simone Crivellaro More articles by this author Expand All Advertisement PDF downloadLoading ...

194 Intraoperative Neurophysiology Clues to Predict Success from Selective Dorsal Rhizotomy for Spastic Diplegic and Hemiplegic Cerebral Palsy

INTRODUCTION: Selective dorsal rhizotomy (SDR) involves differential lesioning of divided sensory rootlets at the L1-S1 spinal levels based on interpretations of intraoperative neurophysiologic recordings. It has been shown to improve spasticity related to Cerebral Palsy, but the relationship of specific intraoperative neurophysiology measurements with clinic findings and improvements from surgery has not been investigated. METHODS: We performed a retrospective chart review of 39 consecutive SDRs on pediatric patients with spastic diplegia and hemiplegia, recording preoperative and postoperative toeing, scissoring, crouching, ability to walk, intraoperative stimulation frequencies, the spread of activated muscles, and whether a rootlet was lesioned. Improvement in clinical findings was analyzed as the correlate of surgical success. RESULTS: There was greater improvement in walking ability with more rootlets having a contralateral spread (p = .009), when more of the lesioned rootlets had contralateral spread (p = .005), and when some rootlets with contralateral spread were spared (p = .001). Among patients with preoperative toeing, there was more muscle activation intraoperatively (p &lt; .001), greater improvement in walking ability (p &lt; .001), and greater improvement of toeing when a lower percentage of rootlets were lesioned intraoperatively (p = .033). Among patients with preoperative crouching, there was greater improvement in crouching with smaller differences in stimulation frequency threshold between the motor and sensory roots (p = .041) and when some rootlets with contralateral spread were spared (p = .028). CONCLUSIONS: There is a correlation between preoperative clinical findings, intraoperative neurophysiology measurements, and postoperative clinical findings. These allow for the prediction of intraoperative recordings based on preoperative presentation. We have shown that success from SDR can be predicted using specific intraoperative measurements.

840 Dorsolateral Prefrontal Cortex Beta Power Dynamics Underlying Verbal Working Memory Encoding in Parkinson’s Disease

INTRODUCTION: Cognitive impairment (CI) is the most frequent nonmotor symptom in Parkinson’s Disease (PD) and is associated with deficits in executive functions such as working memory (Kehagia et al, 2010). Previous studies have demonstrated that caudate and DLPFC beta power underlie learning and working memory (Bick et al, 2019). Decreased dopamine in motor cortico-striato-thalamo-cortical (CSTC) circuits results in increased beta power and PD motor symptoms (Lapidus et al, 2014). Analogous changes in cognitive CSTC circuits, including the dorsolateral prefrontal cortex (DLPFC), may contribute to PD CI and be a target for neuromodulation. Better understanding of anatomic structures and neurophysiologic changes associated with working memory deficits is needed to develop potential neuromodulatory treatment strategies for PD CI. METHODS: Thirteen PD and ten ET patients who underwent deep brain stimulation in 2021 at Vanderbilt University Medical Center were consented and included in this analysis. Intraoperative local field potential recordings were obtained from the DLPFC during a 2-back verbal memory task with performance feedback (Owen et al, 2005). Signals were sampled at 1000Hz, Butterworth band pass filtered, de-meaned and averaged across patients. Average beta power differences 500-1000 msec following image onset were analyzed for correct and incorrect trials for PD and ET patients. RESULTS: PD patients exhibited significantly lower mean beta power compared to ET patients for correct trials (p = 0.0305, Wilcoxon rank-sum test). CONCLUSIONS: Neurophysiologic patterns underlying working memory encoding deficits in PD patients may reflect underlying dopaminergic dysfunction in cognitive CSTC circuits that result in CI. Structures within this circuit may be implicated in PD memory impairment and may serve as potential secondary targets for neuromodulation to improve working memory in patients with comorbid CI.

105 Value of Atlas-Based Data and Intraoperative Testing in Deep Brain Stimulation

INTRODUCTION: Deep brain stimulation (DBS) is commonly performed awake to collect intraoperative microelectrode recordings (MER) and macrostimulation to optimize efficacy and minimize side effects (Bour et al, 2010). With supplementary information from an atlas-based database (CranialVault), efficacy heat maps guide initial targeting, intraoperative final electrode position (FEP) selection and post-operative programming (D’Haese et al, 2012). A better understanding of how this data is integrated to inform all stages of DBS can assist in reducing OR time, optimizing electrode position, expediting programming, and enhancing patient outcomes. METHODS: 451 individual patients who underwent DBS for Parkinson’s Disease, Essential Tremor or Dystonia, treated with 822 individual leads, at Vanderbilt University Medical Center between 2011-2021 were included. Intraoperative testing data including MER firing rate, macrostimulation efficacy and coordinates of FEP were retrieved from the CranialVault database. Average coordinates of planned target, midpoint and bottom of FEP, active contact and centroid of heat maps per target in patient space were calculated and visualized. Medical charts were reviewed for 1-year post-operative outcomes. RESULTS: The distribution of FEPs per target include 55.2% of leads placed in center track. Average coordinates in patient space of planned target, centroid of heatmap, midpoint and bottom of FEP and active contact were recorded. MER data demonstrates how multiunit activity changes at different depths relative to target, per target. Patients who achieve 4th quartile efficacy intraoperatively are more likely to achieve maximal benefit at 1-year post-op (p = 0.003, chi-squared). CONCLUSIONS: Atlas-based data and intraoperative testing is valuable, often leads to changes in FEP and can predict post-operative outcomes.