Intraoperative Tool Research Articles

Palatal Position of Patient Tracker for Magnetic Neuronavigation System: Technical Note

Recently, the neuronavigation system (NS) has become an essential intraoperative tool for many neurosurgical procedures, allowing for precise lesion localization. It is particularly important to avoid errors during the navigation process. Here we report a novel technique using palatal positioning of the patient tracker to ensure optimal accuracy during magnetic navigation in various neurosurgical procedures. This retrospective study included a total of 34 patients treated in our institution between June 2017 and January 2018. The patients were split into 2 groups who underwent surgery under general anesthesia: a microscopic transcranial group and an endoscopic endonasal group. Preoperative and postoperative navigation accuracy was assessed by 2 neurosurgeons. After our surgical planning navigation protocol was applied, both transcranial and endonasal procedures were successfully performed under navigation guidance in all but 1 patient. There were no intraoperative or postoperative complications related to the tracker mounted under the hard palate. In 33 cases a maximal tracking view and optimal navigation accuracy was achieved, for a success rate of 97%. The positioning of the patient tracker under the hard palate proved safe, accurate, and feasible in 97% of our patients. In our case series, it met the main goal of avoiding device displacement without a sense of invasiveness and postoperative patient discomfort.

One-Step Nucleic Acid Amplification (OSNA): A fast molecular test based on CK19 mRNA concentration for assessment of lymph-nodes metastases in early stage endometrial cancer.

IntroductionThe aim of the current study is to evaluate the detection rate of micro- and macro-metastases of the One-Step Nucleic Acid Amplification (OSNA) compared to frozen section examination and subsequent ultra-staging examination in early stage endometrial cancer (EC).Material and methodsFrom March 2016 to June 2016, data of 40 consecutive FIGO stage I EC patients were prospectively collected in an electronic database. The sentinel lymph node mapping was performed in all patients. All mapped nodes were removed and processed. Sentinel lymph nodes were sectioned and alternate sections were respectively examined by OSNA and by frozen section analysis. After frozen section, the residual tissue from each block was processed with step-level sections (each step at 200 micron) including H&E and IHC slides.ResultsSentinel lymph nodes mapping was successful in 29 patients (72.5%). In the remaining 11 patients (27.5%), a systematic pelvic lymphadenectomy was performed. OSNA assay sensitivity and specificity were 87.5% and 100% respectively. Positive and negative predictive values were 100% and 99% respectively, with a diagnostic accuracy of 99%. As far as frozen section examination and subsequent ultra-staging analysis was concerned, we reported sensitivity and specificity of 50% and 94.4% respectively; positive and negative predictive values were 14.3% and 99%, respectively, with an accuracy of 93.6%. In one patient, despite negative OSNA and frozen section analysis of the sentinel node, a macro-metastasis in 1 non-sentinel node was found.ConclusionsThe combination of OSNA procedure with the sentinel lymph node mapping could represent an efficient intra-operative tool for the selection of early-stage EC patients to be submitted to systematic lymphadenectomy.

An evidence-based intraoperative communication tool for emergency general surgery: a pilot study

BackgroundEmergency general surgery (EGS) is characterized by high rates of morbidity and mortality. Though checklists and associated communication-based huddle strategies have improved outcomes, these tools have never been specifically examined in EGS. We hypothesized that use of an evidence-based communication tool aimed to trigger intraoperative discussion could improve communication in the EGS operating room (OR). Materials and methodsWe designed a set of discussion prompts based on modifiable factors identified from previously published studies aimed to encourage all team members to speak up and to centralize awareness of patient disposition and intraoperative transfusion practices. This tool was pilot-tested using OR human patient simulators and was then rolled out to EGS ORs at an academic medical center. The perceived effect of our tool's implementation was evaluated through mixed-methodologic presurvey and postsurvey analysis. ResultsPreimplementation and postimplementation survey-based data revealed that providers reported the EGS-focused discussion prompts as improving team communication in EGS. A trend toward shared awareness of intraoperative events was observed; however, nurses described cultural impedance of discussion initiation. Providers described a need for further reinforcement of the tool and its indications during implementation. ConclusionsUse of a discussion-based communication tool is perceived as supporting team communication in the EGS OR and led to a trend toward improving a shared understanding of intraoperative events. Analyses suggest the need for enhanced reinforcement of use during implementation and improvement of team-based education regarding EGS. Furthermore work is needed to understand the full impact of this evidence-based tool on OR team dynamics and EGS patient outcomes.

OpTrust: Validity of a Tool Assessing Intraoperative Entrustment Behaviors.

The aim of this study is to establish evidence to support the validity of a novel faculty-resident intraoperative assessment tool for entrustment known as OpTrust. Recently, the landscape of surgical training has been altered, in part, because of resident work-hour changes and increased supervision requirements. To address these concerns, a new model for assessment of teaching and learning in surgical residencies must be anchored on progression through milestones and entrustment. OpTrust was designed to assess the faculty-resident dyad in the operating room and measure the entrustment exhibited during intraoperative interactions across 5 domains: (i) types of questions asked, (ii) operative plan, (iii) instruction, (iv) problem solving, and (v) leadership by the surgical resident. After initial pilot testing and refinement of OpTrust, 5 individual raters underwent rater training sessions; 49 individual operating room observations were completed based on 28 cases. OpTrust, as a tool for assessing intraoperative entrustment, is supported by strong validity evidence. In part, it demonstrates strong interrater reliability across all faculty domains as measured by intraclass correlation 1 (ICC1) (0.81-0.93). For resident domains the results were similar with ICC1 (0.84-0.94). Cronbach alpha was 0.89 and 0.87 for faculty and resident entrustment respectively, signifying the 5 domains could be combined into a single construct of entrustment. A high correlation existed between faculty and resident scores (Pearson r = 0.94, P < 0.001) indicating a strong positive linear relationship between faculty and resident mean entrustment scores across all scale domains. OpTrust successfully assesses behaviors associated with entrustment during intraoperative faculty-resident interactions, and has the potential to be adopted across other procedural-based specialties to promote autonomous training progression.

Is cricothyroid muscle twitch predictive of the integrity of the EBSLN in Thyroid Surgery?

Cricothyroid (CT) muscle twitch inspection with neurostimulation is a widely accepted method to identify the external branch of the superior laryngeal nerve (EBSLN) and its integrity in thyroid surgery. However, there has been no large-scale research to evaluate the diagnostic values of CT muscle twitch inspection based on postoperative electromyography (EMG) results, which are considered the gold standard. In this study, we aimed to demonstrate the diagnostic value of CT muscle twitch inspection based on postoperative EMG. Prospective cohort study. A total of 454 patients underwent primary thyroid surgery. Among them, 55 patients were excluded because of preoperative vocal fold palsy, problems with the stimulator, or refusal to participate in the EMG study. Finally, 399 patients were prospectively enrolled in this study. Intraoperatively, CT muscle twitch was inspected with neurostimulation. Bilateral EMG examination of the CT muscle was performed 2 to 3 months postoperatively in all patients. A total of 712 EBSLNs at risk were analyzed in this study. Of these, 21 (2.9%) nerves were visually identified, and positive CT muscle twitch by neurostimulation was observed in 694 (97.5%). Normal results on postoperative EMG of the CT muscle were reported in 657 (92.3%). Sensitivity, specificity, positive predictive value (PPV), and negative predictive value (NPV) were 97.7%, 5.5%, 92.5%, and 16.7%, respectively. CT muscle twitch inspection could be a useful intraoperative tool to determine EBSLN integrity considering its high sensitivity and PPV. However, the test may not completely replace EMG for evaluating EBSLN integrity due to its low specificity and NPV. 2b. Laryngoscope, 2654-2661, 2018.

High-throughput ultraviolet photoacoustic microscopy with multifocal excitation.

Ultraviolet photoacoustic microscopy (UV-PAM) is a promising intraoperative tool for surgical margin assessment (SMA), one that can provide label-free histology-like images with high resolution. In this study, using a microlens array and a one-dimensional (1-D) array ultrasonic transducer, we developed a high-throughput multifocal UV-PAM (MF-UV-PAM). Our new system achieved a 1.6 ± 0.2 μm lateral resolution and produced images 40 times faster than the previously developed point-by-point scanning UV-PAM. MF-UV-PAM provided a readily comprehensible photoacoustic image of a mouse brain slice with specific absorption contrast in ∼16 min, highlighting cell nuclei. Individual cell nuclei could be clearly resolved, showing its practical potential for intraoperative SMA.

Noninvasive Multimodal Imaging of Osteosarcoma and Lymph Nodes Using a 99mTc-Labeled Biomineralization Nanoprobe.

The accurate imaging of the lymph nodes represents a critical indicator for tumor staging and surgical planning (e.g., osteosarcoma). Clinically, nodal tracing using a radio-nanocolloid is often limited by the inaccessibility of real-time images and inadequate anatomical information. Herein, we present a 99mTc-labeled biomineralization nanoprobe for the advanced detection of osteosarcoma and lymph nodes with multimodal imaging. Through the exploitation of the complementary strengths of MRI/SPECT/NIR fluorescence, the fabricated nanoprobe exhibited suitable stability and biocompatibility characteristics and was shown to be able to be located in osteosarcoma. The lymphatic drainage and network in healthy mice were imaged in real-time using NIR fluorescence and SPECT/CT. Furthermore, we demonstrated that our 99mTc-biomineralization nanoprobe could be used for the high-resolution and high-sensitivity imaging analysis of lymphatic drainage in an orthotopic osteosarcoma model. Overall, the 99mTc-labeled biomineralization nanoprobe features promising characteristics to be used as an intraoperative visualization tool to aid in precise tumor imaging and nodal resection.

Transcranial Doppler for Eagle Syndrome: Rare Presentation of Unilateral Internal Carotid Artery Compression by the Stylohyoid Ligament With Provocative Maneuvers

Eagle syndrome is a rare condition caused by compression of the internal carotid artery (ICA) or cranial nerves by an elongated styloid process or calcified stylohyoid ligament. This patient is a 56 year-old woman who presented with episodes of positional syncope for 8 years. Transcranial Doppler (TCD) demonstrated abnormally decreased flow in the left middle cerebral artery (MCA) during the syncopal episodes. The patient was evaluated by TCD, transcranial imaging (TCI), and carotid duplex (CD). First, a baseline CD and TCI were performed with the patient in a neutral position. TCD was then used during symptomatic provocative maneuvers to monitor the bilateral MCAs. Intraoperative TCD monitoring was also done during bilateral stylohyoid ligament resection, and postoperatively during the same provocative maneuvers. The baseline CD examination revealed normal extracranial carotid anatomy; TCD and TCI showed normal mean velocities and a normal anatomic variant of fetal origin of the left posterior cerebral artery. During provocative maneuvers, TCD showed abnormally dampened to absent flow in the left MCA, consistent with compression of the left extracranial ICA. CT scan confirmed elongated stylohyoid ligaments bilaterally. The MCA mean velocities were monitored intraoperatively and postoperatively by TCD and showed no changes with head positioning immediately following resection of the stylohyoid ligaments. The patient reported no syncopal episodes at follow-up 6 days after surgery. Although rare, Eagle syndrome should be considered as a cause of positional syncope. TCD can serve as a diagnostic test, an intraoperative monitoring tool, and a method for documenting the surgical outcome.

Intraoperative optische Kohärenztomographie bei explorativer Vitrektomie an Patienten mit Glaskörperblutung – eine Fallserie

High-resolution spectral domain optical coherence tomography (SD-OCT) is agold standard technique for diagnosis, management and monitoring of patients with vitreoretinal diseases. Preoperative diagnostics for evaluation of intraocular and retinal status in patients with vitreous haemorrhage are limited, thus final therapeutic decisions can only be made during explorative vitrectomy. We evaluated the use of intraoperative SD-OCT (iSD-OCT) as areal-time additional diagnostic tool during explorative vitrectomy in patients with vitreous haemorrhage. We report on 9patients (11eyes) with vitreous haemorrhage. Preoperative ultrasound was performed to evaluate intraocular status. Subsequently, an explorative 23G pars plana vitrectomy was performed under visualisation with the OPMI Lumera700 surgical microscope (Carl Zeiss Meditec, Jena, Germany) equipped with afully integrated iSD-OCT device (Rescan 700, Carl Zeiss Meditec, Jena, Germany) as areal-time diagnostic tool. In all patients, intraoperative iSD-OCT allowed real-time evaluation of the preretinal, intraretinal and subretinal structures in addition to the intraoperative en face image. The further surgical strategy, i. e. necessity for peeling of epiretinal membranes (ERM) or of the inner limiting membrane (ILM), application of intravitreal medication and selection of the appropriate tamponade, was based on and optimised according to the iSD-OCT images. Intraoperative iSD-OCT is highly useful as an additional intraoperative diagnostic tool in patients with vitreous haemorrhage. In addition to the en face microscope image, it facilitates intraoperative real-time diagnosis and aids therapeutic decision-making during surgery.

Abstract P6-03-10: Using high-frequency ultrasound (20-80 MHz) to differentiate malignant vs benign breast tissue in surgical margins

Abstract The use of high-frequency (HF) ultrasound (20-80 MHz) to determine tissue pathology is an inexpensive and real-time tool for differentiation of surgical margin specimens from breast conservation surgery (BCS). The development of this method as an intraoperative tool for BCS would greatly reduce the rate of re-excisions due to positive breast tissue margins. HF ultrasound was previously used in a 17-patient study to determine differences in breast tissue pathology of 34 surgical margins. Results from this pilot study demonstrated high accuracy, specificity, and sensitivity in the HF ultrasound data, and showed the immense potential of this method as a breast cancer detection tool. A large-scale validation study of this method was subsequently conducted using 349 margin specimens taken from 73 patients during BCS. Specimens ranged from 1-5 cm in length and width, 0.2-1.6 cm in thickness, and did not require any additional procedures or resection that affected the patient or surgical outcome. Each specimen was tested with HF ultrasound immediately following resection and then forwarded to pathology. Through-transmission data were collected from the specimens using two broadband, single-element transducers with a 50-MHz peak frequency (Olympus NDT, V358-SU), a HF square-wave pulser/receiver (UTEX, UT340), and a 1-GHz digital oscilloscope (Agilent, DSOX3104A). Peak density (the number of peaks and valleys in the 20-80 MHz frequency spectra range) and attenuation data were calculated from the ultrasonic spectra and waveforms, respectively. Peak density and attenuation correlate directly to tissue malignancy, and thresholds for these two parameters for differentiating benign vs. malignant tissue were determined using Fisher's Exact Test applied to the previously collected pilot study data. The peak density and attenuation results were then combined using a multivariate analysis. Since the ultrasonic measurements were collected on a per position basis (1-5 positions per margin), but the histopathology results were reported on a per specimen basis, the statistical measures for the ultrasonic results were calculated using two methods. First, the statistical measures were calculated based on a per position basis, where the pathology of each position was determined by the pathology results for the entire specimen. Second, the statistical measures were calculated based on a per specimen basis, where only one measurement position on each margin was selected (based on the highest peak density value) to correlate to the specimen pathology. The results of the first approach (per position basis) showed a sensitivity of 82.6%, a specificity of 72.3%, and an accuracy of 72.7%. The results of the second approach (per specimen basis) showed a sensitivity of 82.6%, a specificity of 61.7%, and an accuracy of 63.0%. The results of this study show potential for a rapid and inexpensive method of determining pathology of breast tissue surgical margins during BCS. This work was supported by funds from the Elsa U. Pardee Foundation, the Eppley Foundation for Research, the Western Alliance for Expanding Student Opportunities, theGovernor's Office of Economic Development of the State of Utah, the University of Utah, and Utah Valley University. Citation Format: Carter C, Neumayer LA, Factor RE, Doyle TE. Using high-frequency ultrasound (20-80 MHz) to differentiate malignant vs benign breast tissue in surgical margins [abstract]. In: Proceedings of the 2017 San Antonio Breast Cancer Symposium; 2017 Dec 5-9; San Antonio, TX. Philadelphia (PA): AACR; Cancer Res 2018;78(4 Suppl):Abstract nr P6-03-10.

StimVision Software: Examples and Applications in Subcallosal Cingulate Deep Brain Stimulation for Depression

Create a software tool to facilitate tractography-based deep brain stimulation (DBS) electrode targeting within the patient-specific stereotactic coordinate system used in the operating room. StimVision was developed with Visualization Toolkit libraries and integrates four major components: 1) medical image visualization, 2) tractography visualization, 3) DBS electrode positioning, and 4) DBS activation volume calculation with tractography intersection. Initial applications of StimVision are focused on the study of subcallosal cingulate (SCC) DBS for the treatment of depression. Retrospective modeling results on SCC DBS have suggested that direct stimulation of a specific collection of tractographic pathways are necessary for therapeutic benefit; thereby creating a tractography-based DBS surgical targeting hypotheses. StimVision is the tool we created to facilitate prospective clinical evaluation of that hypothesis. Retrospective tractography-based analyses are common in DBS research; however, intraoperative software tools for interactive selection of a tractography-based DBS target are not readily available. StimVision provides an academic research tool to assist clinical implementation of new DBS targeting strategies and postoperative evaluation of targeting outcome.

Assessment of the praxis circuit in glioma surgery to reduce the incidence of postoperative and long-term apraxia: a new intraoperative test.

OBJECTIVEApraxia is a cognitive-motor deficit affecting the execution of skilled movements, termed praxis gestures, in the absence of primary sensory or motor disorders. In patients affected by stroke, apraxia is associated with lesions of the lateral parietofrontal stream, connecting the posterior parietal areas with the ventrolateral premotor area and subserving sensory-motor integration for the hand movements. In the neurosurgical literature to date, there are few reports regarding the incidence of apraxia after glioma surgery. A retrospective analysis of patients who harbored a glioma around the central sulcus and close to the parietofrontal circuits in depth showed a high incidence of long-term postoperative hand apraxia, impairing the patients' quality of life. To avoid the occurrence of postoperative apraxia, the authors sought to develop an innovative intraoperative hand manipulation task (HMt) that can be used in association with the brain mapping technique to identify and preserve the cortical and subcortical structures belonging to the praxis network.METHODSThe intraoperative efficacy of the HMt was investigated by comparing the incidence of postoperative ideomotor apraxia between patients undergoing mapping with (n = 79) and without (n = 41) the HMt. Patient groups were balanced for all demographic and clinical features.RESULTSIn patients with lesions in the dominant hemisphere, the HMt dramatically reduced the incidence of apraxia, with a higher sensitivity for the ideomotor than for the constructional abilities; patients with lesions in the nondominant hemisphere benefitted from the HMt for both ideomotor and constructional abilities. The administration of the test did not reduce the extent of resection.CONCLUSIONSThe HMt is a safe and feasible intraoperative tool that allowed surgeons to prevent the occurrence of long-term hand apraxia while attaining resection goals for the surgical treatment of glioma.

Restoration of Blood Flow to the Proximal Femoral Epiphysis in Unstable Slipped Capital Femoral Epiphysis by Modified Dunn Procedure: A Preliminary Angiographic and Intracranial Pressure Monitoring Study.

The major complication of unstable slipped capital femoral epiphysis (SCFE) is avascular necrosis (AVN) of the femoral head. The purpose of this study was to document by angiography the preoperative and postoperative perfusion to the proximal femoral epiphysis following an unstable SCFE. A specific aim was to determine whether blood flow could be restored. A secondary aim was to determine the efficacy of an intracranial pressure (ICP) monitor to assess blood flow within the femoral head intraoperatively. Nine patients with an unstable SCFE underwent superselective angiogram of the medial circumflex femoral artery preoperatively, followed by operative fixation with an open reduction using a modified Dunn approach. Femoral head blood flow was evaluated with an ICP monitor. Angiography was repeated postoperatively. Patients were followed radiographically to assess for AVN. Follow-up averaged 22 months. Six patients did not have arterial flow to the femoral head on the preoperative angiogram. Flow was restored postoperatively on angiogram in 4 of the 6 patients. Two patients developed AVN. One had no flow to the femoral head preoperatively or postoperatively on angiogram and complete tearing of the periosteum was noted. In 1 patient, there was no ICP waveform after the initial reduction. After removing more callous and repeating reduction, the waveform returned. Of the 2 patients with AVN, 1 had an ICP waveform after reduction. This study documents that some patients with unstable SCFE present with reduced femoral head blood supply due to SCFE. It also demonstrates blood flow restoration in 4 patients by angiogram and 5 by ICP monitor after surgical treatment. No patient immediately lost blood flow due to surgery. ICP monitor is a safe intraoperative tool for real-time assessment of femoral head blood flow during open reduction of unstable SCFE. Presence of flow by ICP is not a guarantee that AVN will not develop, but absence of flow was predictive of AVN. Therapeutic level I-prognostic. See Instructions for Authors for a complete description of levels of evidence.

Intraoperative epicardial focal pulmonary venous electrocardiography in patients with atrial fibrillation.

In patients referred to off-pump coronary artery bypass grafting, pulmonary vein isolation (PVI) may be used for those with persistent atrial fibrillation (AF), an alternative to the Maze procedure. However, the success rate of PVI in persistent AF is limited. The study assesses the prognostic value of focal epicardial electrocardiography of the pulmonary veins (PVs) for surgical ablation results. We mapped 140 PV in 35 cases undergoing off-pump coronary artery bypass grafting. Data obtained using a sensing-pacing probe before ablation were analysed. The composite study end-point consisted of the need for electrical cardioversion for in-hospital recurrence of AF and the presence of AF at hospital discharge and after 6 months follow-up confirmed by 24-h Holter electrocardiographic monitoring. In patients with epicardial far-field (FF) signals recorded over at least 1 PV, the composite end-point occurred in 61% (14) vs 25% (3) of patients with no FF signal recorded over any PV (P = 0.04). The presence of FF signals in at least 1 PV significantly increased the risk of composite end-point occurrence (odds ratio 3; P = 0.04). The composite end-point occurred in 86% (6) of patients with FF signals recorded over all PVs and in 39% (11) in the remainder of the study population (P = 0.03). Intraoperative epicardial focal electrocardiography of PVs revealed more than 40% of PVs had only FF atrial signals. The presence of FF signals in PVs is related to a lower early effectiveness of PVI on ablating AF. Epicardial focal electrocardiography of PVs may be a clinically effective intraoperative tool in the decision-making process between less invasive PVI and the standard Maze procedure.

Fluorescein videoangiography during extracranial-to-intracranial bypass surgery: preliminary results.

Over the last years, intraoperative use of fluorescein is gaining ground in the field of neurosurgery, due to development of a microscope-integrated YELLOW 560 module, with reported experiences in brain malignancies, aneurysms, and arteriovenous malformation surgery. The aim of this study is to determine the feasibility and value of fluorescein videoangiography during bypass procedures. The authors enrolled 11 patients who underwent extracranial-to-intracranial bypass for moyamoya disease, atherosclerotic steno-occlusive cerebrovascular disease, and flow replacement during a giant middle cerebral artery (MCA) aneurysm treatment. Patients underwent fluorescein videoangiography using microscope-integrated fluorescence module. In all 11 cases, good bypass patency was intraoperatively demonstrated through fluorescein videoangiography and confirmed by post-operative digital subtraction angiography or computed tomographic angiography. The technique seems to be less sensible than standard indocyanine green videoangiography in terms of flow velocity assessment during first pass and does not benefit from a dedicated software to perform hemodynamic parameter analysis (i.e., FLOW 800). Fluorescein videoangiography was able to show a higher number of vesselsthanindocyanine green videoangiography, providing an extremely well-defined view of cortical vascular network, also in deeper cortical areas. In case of deep-seated anastomosis, it allowed real-time manipulation of neurovascular structures, making it possible a safe analysis of vessels in deep surgical field during videoangiography observation. Fluorescein videoangiography is a cost-effective, easy-to-use, fast and safe intraoperative tool and is useful to assess graft patency and extent of cortical vascular network also in deeper cortical areas. In case of deep-seated anastomosis, it provides the great advantage of performing real-time manipulation of neurovascular structures during videoangiography observation. It could represent a valuable complementary or alternative technique to assess intraoperative bypass function.

One-step nucleic acid amplification: the possible value in assessing sentinel lymph node metastasis during mastectomy.

Breast cancer is the most common cancer in women, worldwide, and 1,400 deaths per day are attributed to it. The success of national screening programs has seen breast cancers being diagnosed at an earlier stage. With conservative surgery to the breast demonstrating equivalent long-term outcomes, the last 10 years have seen a growing interest in the safety of less invasive management for the axilla in breast cancer patients. One-step nucleic acid amplification (OSNA) is a validated, reliable, and efficient tool in identifying micro- and macro-metastases intraoperatively. It is the most widely used intraoperative analysis tool within the United Kingdom, and is employed by over 320 units across Europe and Asia. Recent evidence from the AMAROS, IBCSG 23-01, and ACOSOG Z0011 trials has changed surgical practice in managing the axilla of patients with breast cancer. We propose a clinical algorithm demonstrating the role of OSNA as an intraoperative analysis tool in today’s management of breast cancer as well as prospects for the future use of OSNA.

18F]fluoroethyltyrosine-induced Cerenkov Luminescence Improves Image-Guided Surgical Resection of Glioma.

The extent of surgical resection is significantly correlated with outcome in glioma; however, current intraoperative navigational tools are useful only in a subset of patients. We show here that a new optical intraoperative technique, Cerenkov luminescence imaging (CLI) following intravenous injection of O‑(2-[18F]fluoroethyl)-L-tyrosine (FET), can be used to accurately delineate glioma margins, performing better than the current standard of fluorescence imaging with 5-aminolevulinic acid (5-ALA).Methods: Rats implanted orthotopically with U87, F98 and C6 glioblastoma cells were injected with FET and 5-aminolevulinic acid (5-ALA). Positive and negative tumor regions on histopathology were compared with CL and fluorescence images. The capability of FET CLI and 5-ALA fluorescence imaging to detect tumor was assessed using receptor operator characteristic curves and optimal thresholds (CLIOptROC and 5-ALAOptROC) separating tumor from healthy brain tissue were determined. These thresholds were used to guide prospective tumor resections, where the presence of tumor cells in the resected material and in the remaining brain were assessed by Ki-67 staining.Results: FET CLI signal was correlated with signal in preoperative PET images (y = 1.06x - 0.01; p < 0.0001) and with expression of the amino acid transporter SLC7A5 (LAT1). FET CLI (AUC = 97%) discriminated between glioblastoma and normal brain in human and rat orthografts more accurately than 5-ALA fluorescence (AUC = 91%), with a sensitivity >92% and specificity >91%, and resulted in a more complete tumor resection.Conclusion: FET CLI can be used to accurately delineate glioblastoma tumor margins, performing better than the current standard of fluorescence imaging following 5-ALA administration, and is therefore a promising technique for clinical translation.

Role of Squash Cytology in Intraoperative Diagnosis of Spinal Lesions.

Background:Squash cytology for intra operative diagnosis of central nervous system (CNS) tumors is an immensely important modality. Though its role in brain lesions is unquestionable and has been proven in a number of studies, its utility for spinal lesions is still a grey zone.Aims:To assess the diagnostic accuracy of squash preparation in spinal lesions and its statistical significance (sensitivity, specificity, positive predictive value, negative predictive value) following histological confirmation.Materials and Methods:A total of 57 cases of spinal tumors were taken. May-Grunewald-Giemsa staining (MGG) and Hematoxylin-Eosin (H&E) were done in each one of them. Rest of the tissue was processed for histological diagnosis and results were compared.Results:In our study, histology was taken as the gold standard. By comparing the results, squash preparation had sensitivity of 95.75%, specificity 80.0%, positive predictive value (PPV)95.74%, and negative predictive value (NPV) 80.80%. Schwannoma was found to be the most prevalent tumor in the spine (17/57) in our study, followed by meningioma (13/57). Diagnostic accuracy for schwannoma was fairly high i.e. 92.3%, followed by meningioma (82.35%). Highest diagnostic accuracy was documented in intradural, extramedullary compartment.Conclusion:Inspite of having pitfalls and various limitations in case of spinal lesions, squash preparation is a rapid and easy method with fairly high diagnostic accuracy. So it can be reliably used as an intraoperative diagnostic tool in spinal lesions.

Intraoperative Parathyroid Hormone Monitoring in Guiding Adequate Parathyroidectomy.

Background:Parathyroidectomy has been traditionally performed through bilateral neck exploration (BNE). However, with the use of intraoperative parathyroid hormone (IOPTH) assay along with preoperative localization studies, focused parathyroidectomy can be performed with good surgical success rate, multiglandular disease can be predicted, and hence recurrence and surgical failure can be prevented. Furthermore, it predicts eucalcemia in the postoperative period. The aim of this study was to evaluate the usefulness of IOPTH assay in guiding adequate parathyroidectomy in patients of primary hyperparathyroidism.Materials and Methods:Between year 2015 and 2017, 45 patients of primary hyperparathyroidism underwent parathyroidectomy with IOPTH assay employed as an intraoperative tool to guide the surgical procedure. Blood samples were collected: (1) at preincision time, (2) preexcision of gland, (3) 5-min postexcision of gland, and (4) 10-min postexcision of gland. On the basis of the Irvin criterion, an intraoperative PTH drop >50% from the highest either preincision or preexcision level after parathyroid excision was considered a surgical success. Otherwise, BNE was performed and search for other parathyroid glands done.Results:Ten-min postexcision PTH levels dropped >50% in 34 (75.6%) patients. True positive among them were 31 (68.8%), true negative 8 (17.7%), false positive 3 (6.6%), and false negative 3 (6.6%). We performed focused exploration at the outset in 40 (88.9%) patients and bilateral exploration for five patients as guided by preoperative localizing studies. Hence, IOPTH was helpful in guiding further exploration in 8 (17.7%) patients and prevented further exploration in 32 (71.1%) patients and also was able to predict eucalcemia in 97.7% patients at 6 months. Thus, IOPTH was able to obviate or to ask for additional procedure in 88.8% of patients. However, in three (6.6%) patients, IOPTH would guide unnecessary exploration and in equally, that is, three (6.6%) patients may require reoperation for unidentified parathyroids.Conclusion:IOPTH in adjunct with other localizing studies is very helpful for carrying out successful parathyroidectomy in uniglandular disease and predicting postoperative eucalcemia. However, more importantly, its role is valuable in equivocal imaging, in such cases, it prevents unnecessary exploration or helps in adequate parathyroidectomy.

Open-cell stent and use of cone-beam CT enables a safe and effective coil embolization of true ophthalmic artery and anterior choroidal artery aneurysms with preservation of parent vessel: Clinical and angiographic results.

Background Treatment of true ophthalmic artery (OA) or anterior choroidal artery (AChA) aneurysms with preservation of the parent vessel may be challenging. Flow diverters have limitations when dealing with branch vessels arising from the aneurysm sac. Visual loss or AChA territory infarcts have been reported both for surgical and endovascular treatment. Methods We evaluated the safety and efficacy of an open-cell design, laser-cut, self-expanding Nitinol stent, and use of cone-beam computed tomography (CBCT) for stent-assisted coil embolization. Results A total of seven patients with unruptured OA or AChA aneurysms were enrolled in this prospective small case study and the data were analyzed retrospectively. A complete obliteration was achieved in all aneurysms immediately post-intervention or at six-month follow-up without any evidence for recanalization at up to three-year follow-up. All patients tolerated the procedure well and there was no change in baseline modified Rankin Scale. Conclusions Our study suggests that specific features of an open-cell stent allow a safe and effective treatment of OA or AChA aneurysms with a high technical success rate and excellent mid-term angiographic and clinical outcome. CBCT is a useful intraoperative imaging tool.