Intraoperative Flow Research Articles

Flow capacity of a superficial temporal artery as a donor in a consecutive series of 100 patients with superficial temporal artery-middle cerebral artery bypass.

A superficial temporal artery-middle cerebral artery (STA-MCA) bypass is classically considered a low-flow bypass. It is known that the flow in the flow augmentation STA-MCA bypass is influenced by flow demand of the revascularized territory and can reach significantly higher values. The authors report their intraoperative flow measurement data in a consecutive series of 100 STA-MCA bypasses performed at their institution. Moreover, in a subanalysis, they show the postoperative bypass flow measured with quantitative MR angiography (qMRA) noninvasive optimal vessel analysis (NOVA). Between January 2013 and October 2023, 100 patients with acute, subacute, or chronic large-vessel occlusion (LVO) or moyamoya disease underwent a flow augmentation STA-MCA bypass revascularization at the authors' department with intraoperative bypass flow measurement. Patients with atherosclerotic LVO who underwent bypass surgery within a 6-week period following the onset of ischemic stroke symptoms were categorized into the acute bypass group, encompassing both acute and subacute LVO cases. Conversely, those who underwent bypass surgery > 6 weeks after the last occurrence of ischemic stroke were classified as the chronic group. Since May 2019, a consecutive subgroup of 37 patients received a postoperative (before discharge) bypass flow measurement with the qMRA-NOVA imaging tool. The mean ± SD intraoperative bypass flow in this consecutive series of 100 STA-MCA bypasses was 53.5 ± 28.8 ml/min (range 14-145 ml/min). In the subanalysis, there was no difference in the intraoperative flow capacity between the acute and chronic groups and between the moyamoya and acute groups. Patients in the moyamoya group showed a significantly higher flow rate in the STA-MCA bypass compared with the chronic group (63.0 ± 30.2 ml/min vs 48.4 ± 26.5 ml/min, p = 0.03). In a consecutive subanalysis of 37 STA-MCA bypass cases, postoperative flow measurements were also performed using qMRA-NOVA, showing a significant increase in the flow of STA-MCA bypasses after surgery compared with intraoperative flow measurements (mean intraoperative bypass flow rate vs qMRA-NOVA postoperative bypass flow rate: 73.4 ± 29.9 ml/min vs 111.3 ± 51.4 ml/min, p = 0.005). Using intraoperative and postoperative quantitative flow measurements of the STA, the data confirm that the flow in the flow augmentation STA-MCA bypass is influenced by the flow demand of the revascularized territory and can reach high values if needed. Moreover, the significant flow increase in the postoperative flow measurement using qMRA-NOVA demonstrates that the bypass can increase its flow over time.

The evolution and future directions of bypass surgery.

Cerebral bypass surgery is one of the most complex and elegant procedures in neurosurgery. It involves several meticulous steps that test the skills of even the most prepared neurosurgeons. This surgery has transcended its traditional role in arterial stenosis and atherosclerosis, expanding its applications to include flow preservation techniques for complex conditions such as aneurysms, tumors, and vascular malformations. The decreased number of procedures performed across many hospitals reflects the development of newer endovascular therapies but is also due to the results of the extracranial-intracranial bypass study, the Carotid Occlusion Surgery Study, and the Carotid and Middle Cerebral Artery Occlusion Surgery Study, which have raised questions about the efficacy of cerebral bypass surgery for individuals with carotid artery occlusion who are prone to ischemic stroke. Despite this, there is still a potential benefit of bypass surgery for patients with hemodynamic impairment refractory to medical management. Also, revascularization in moyamoya vasculopathy is an effective strategy for preventing ischemic and hemorrhagic events in both children and adults. Additionally, innovations in the technique, such as the flow-regulated bypass and intraoperative flow assessment, aim to minimize perioperative morbidity. Despite bypass surgery being less performed in this current era, the teaching and development of these skills are still encouraged for future neurosurgeons, as a role for bypass will exist for the foreseeable future.

Robotic Splenic Flexure Takedown: Single Docking Crossed-Arm Technique.

Splenic flexure mobilization is typically required in the management of left-sided colon and rectal resections to achieve tension-free anastomosis. Although the da Vinci Xi® surgical system (Intuitive Surgical, Sunnyvale, CA, USA) was designed for multi-quadrant operations, robotic mobilization of the splenic flexure continues to be challenging for some surgeons. Re-docking and patient repositioning may be required, which can be time-consuming, especially in centers without motion-activated operating tables. However, there are some tips and tricks to overcome these challenges. Here, we describe our single docking crossed-arm technique, which facilitates splenic flexure mobilization. We demonstrate our technique in a 61-year-old woman with sigmoid colon cancer, and informed consent was obtained. The operation starts in the medial-to-lateral approach by ligating the inferior mesenteric artery and vein. After the left colon mobilization, robotic arm one (tip-up fenestrated grasper) is positioned on the patient's left, while arms two, three, and four are on the patient's right. A tip-up fenestrated grasper, inserted through port #1, retracts the descending colon medial and inferior towards the cecum. Then, we cross the arms from the lateral aspect of arm one and takedown the flexure without the collision of robotic arms. After the lateral side dissection is completed, we change the position of the instruments to mobilize the transverse colon. This time, the tip-up grasping instrument is used to retract the colon through the left lower quadrant, which enables us to work in the medial aspect of the grasping instrument. Dissection can be performed using bipolar forceps, monopolar scissors, or vessel-sealing devices. We achieved complete mobilization of the splenic flexure. With this technique, dissection can be carried medially and cranially beyond the falciform ligament. After the splenic flexure takedown and freeing up the mesocolon above the pancreatic body, tension-free anastomosis can be performed. In this approach, re-docking is not necessary. During robotic left-sided colorectal surgery, the crossed-arm technique with single docking avoids robotic arms collision and restricted mobility of the left upper quadrant instrument (port#1). This technique facilitates robotic splenic flexure mobilization and eliminates re-docking/repositioning, leading to shorter operative time and improved intraoperative flow. See Video Vignette.

Intraoperative Flow Cytometry for the Rapid Diagnosis and Validation of Surgical Clearance of Non-Melanoma Skin Cancer: A Prospective Clinical Feasibility Study.

Non-melanoma skin cancer (NMSC) is the most prevalent cancer in humans, with a high global incidence. We present a prospective clinical feasibility study on the use of intraoperative flow cytometry (iFC) for the instant diagnosis of NMSC and its complete surgical clearance. Flow cytometry, a laser-based technique, quantifies cell features, which has applications in cancer research. This study aim is to explore the potential applicability of iFC in detecting and characterizing NMSC and its surgical margins. In total, 30 patients who underwent diagnosis for NMSC were recruited. The method demonstrated high sensitivity (95.2%) and specificity (87.1%), with an accuracy of 91.1%, as confirmed with a receiver operating characteristic curve analysis. The results also indicated that most tumors were diploid, with two cases being hypoploid. The average G0/G1 fractions for normal and tumor tissue samples were 96.03 ± 0.30% and 88.03 ± 1.29%, respectively, with the tumor index escalating from 3.89 ± 0.30% to 11.95 ± 1.29% in cancerous cells. These findings underscore iFC's capability for precise intraoperative NMSC characterization and margin evaluation, promising enhanced complete tumor excision rates. Given the technique's successful application in various other malignancies, its implementation in NMSC diagnosis and treatment holds significant promise and warrants further research in clinical trials.

Combination of intraoperative indocyanine green video-angiography FLOW 800 and computed tomography perfusion to assess the risk of cerebral hyperperfusion syndrome in chronic internal carotid artery occlusion patients after revascularization surgery.

To study the changes of corticocerebral hemodynamics in surgical area and postoperative hyperperfusion syndrome in patients with chronic internal carotid artery occlusion (CICAO) by intraoperative indocyanine green videoangiography (ICGA)-FLOW 800 and CT perfusion after superficial temporal artery (STA)-middle cerebral artery (MCA) bypass surgery. From October 2019 to January 2021, 77 patients diagnosed with CICAO underwent direct bypass surgery at Huadong hospital (affiliated with Fudan University) were enrolled. Regions of interest (ROIs) at STA, proximal MCA (PMCA), distal MCA (DMCA), cortical blood capillary (CBC), and cortical vein (CV) were identified after anastomosis by ICGV-FLOW 800 including peak fluorescence intensity (PFI), time to peak (TTP), and area under the time curve (AUC) of fluorescence intensity. All patients underwent perfusion-weighted CT before bypass surgery and those patients with HPS were verified by CTP after bypass. 14 patients with HPS were verified by perfusion-weighted CT after bypass. In HPS group, the AUCTTP of DMCA was significantly larger (T = -3.301, p = 0.004) and TTP of CBC was shorter (T = -2.929, p = 0.005) than patients in non-HPS group. The larger AUCTTP of DMCA (OR = 3.024, 95%CI 1.390-6.578, p = 0.0050) was an independent risk factor by further multivariate logistic regression analysis. The hemodynamic changes of cortical vessels during STA-MCA bypass surgery could be recorded accurately by ICGV-FLOW 800. Furthermore, the increased AUCTTP of DMCA and shorter TTP of CBC may be potential risk factors of HPS.

Intraoperative transit-time flow measurement of caval veins before and after bidirectional cavopulmonary anastomosis.

Haemodynamic changes in caval venous flow distribution occurring during bidirectional cavopulmonary anastomosis operation are still largely unknown. Transit time flow measurements were performed in 15 cavopulmonary anastomosis operations. Superior and inferior caval vein flows were measured before and after the cavopulmonary anastomosis. Ratio of superior caval vein to overall caval veins flow was calculated. Mean superior caval vein flow ratio before cavopulmonary anastomosis was higher than previously reported for healthy children. Superior caval vein flow ratio decreased in 14/15 patients after cavopulmonary anastomosis: mean 0.63 ± 0.12 before versus 0.43 ± 0.14 after. No linear correlation between intraoperative superior caval vein pressure and superior caval vein flow after cavopulmonary anastomosis was found. Neither Nakata index nor pulmonary vascular resistance measured at preoperative cardiac catheterisation correlated with intraoperative flows. None of patients died or required a take down. The higher mean superior caval vein flow ratio before cavopulmonary anastomosis compared to healthy children suggests flow redistribution in univentricular physiology to protect brain and neurodevelopment. The decrease of superior caval vein flow ratio after cavopulmonary anastomosis may reflect the flow redistribution related to trans-pulmonary gradient. The lack of correlation between superior caval vein pressure and superior caval vein flow could be explained by limited sample size and multifactorial determinants of caval veins flow, although pressure remain essential. Larger sample of measurements are needed to find flow range potentially predictive for clinical failure. To authors' knowledge, this is the first intraoperative flow measurement of both caval veins during cavopulmonary operations.

SURG-05. HYPER SMART CYBER OPERATING THEATER TO PERFORM FUTURE PREDICTIVE SURGERY

Abstract Gliomas are invasive tumors in which the extent of tumor resection is believed to correlate with prognosis. However, aggressive extraction risks deterioration due to functional tissue damage. One strategy for resolving this conflict is the technology of new modalities. The basis of this technology is digital transformation (DX), converting analog information called tacit knowledge on experiences into digital information for explicit knowledge. In the future, we will develop an AI system, generated by DX data, and support intraoperative decision-making with highly accurate future predictions. In order to realize this future-prediction surgery, we have developed a smart cyber operating theater (SCOT) with intraoperative MRI. More than 20 medical devices are connected by middleware (OPeLiNK®), and navigation spatial records and time-synchronized data are displayed on the strategy desk. A hyper version of SCOT has currently performed 277 surgeries, including 262 gliomas, 51 awake craniotomies, and 88 photodynamic therapies. For WHO grade 4 glioblastomas, we try to remove contrast-enhanced areas, and for grade 2/3 gliomas, to formulate an extraction strategy for each 3 genotypes, we perform preoperative AI prediction and intraoperative genetic diagnosis for genotype. Intraoperative flow cytometry is useful to predict the genotype (oligodendroglioma) and determine the extent of resection in some cases. Time-synchronized data showed points of surgical maneuvers causing speech arrest in awake surgery and decreases in MEP, and provided feedback during and after surgery. AI technology is also used for preoperative surgical simulation (GRID®), artifact reduction in iMRI, and brain shift prediction. The hyper SCOT supports the optimal removal of gliomas through intraoperative future prognosis prediction through device data and AI analysis. Furthermore, we are developing an AI robot (AIREC) that performs surgery through deep predictive learning, with the aim of commercialization after 2040. This work was partially supported by JST [Moonshot R&D] [Grant Number JPMJMS2031].

Intraoperative Flow Cytometry Upon and Beyond the Cell Cycle: A Case Study of the Characterization of a Bone Metastasis

The accurate assessment of malignancy and the precise characterization of cancer type are pivotal in guiding clinical decisions and ensuring optimal patient outcomes. The challenging task of identifying the primary site of carcinoma, especially during a surgical procedure, is not always possible and necessitates the exploration of novel, innovative diagnostic techniques. In this report, we detail a unique case of carcinoma of unknown primary origin encountered during an orthopedic surgical procedure. We introduce a novel intraoperative flow cytometry (iFC) methodology, distinctly different from traditional flow cytometry, which is tailored for real-time assessment during surgeries. This iFC technique, applied in a bone metastasis case of unknown primary origin, enabled DNA content analysis and the quantification of cytokeratin for rapid malignancy characterization, presenting an avenue for immediate surgical guidance and decision making. The case was distinctively characterized using iFC, shedding light on the potential of this emerging technique. iFC has been gaining traction because of its ability to facilitate cancer cell assessment and margin evaluation. It has been successfully applied across a wide spectrum of neoplastic conditions. Our innovative, two-step approach using iFC encompasses (1) DNA content analysis, which serves as a reliable indicator for the detection of cancer cells, and (2) the quantification of cytokeratin, a pivotal marker, which aids in the characterization and classification of a malignancy. In this case, the malignancy was classified as a carcinoma. The findings obtained from iFC were subsequently validated through pathology assessment, confirming the accuracy and reliability of our approach. This noteworthy case strengthens the potential of iFC as a novel tool in malignancy assessment, which is not just limited to cell cycle analysis but instead extends beyond this application. The promising results obtained from this case study serve as a testament to the need for more extensive research in clinical studies.

Critical Assessment of Cancer Characterization and Margin Evaluation Techniques in Brain Malignancies: From Fast Biopsy to Intraoperative Flow Cytometry.

Brain malignancies, given their intricate nature and location, present significant challenges in both diagnosis and treatment. This review critically assesses a range of diagnostic and surgical techniques that have emerged as transformative tools in brain malignancy management. Fast biopsy techniques, prioritizing rapid and minimally invasive tissue sampling, have revolutionized initial diagnostic stages. Intraoperative flow cytometry (iFC) offers real-time cellular analysis during surgeries, ensuring optimal tumor resection. The advent of intraoperative MRI (iMRI) has seamlessly integrated imaging into surgical procedures, providing dynamic feedback and preserving critical brain structures. Additionally, 5-aminolevulinic acid (5-ALA) has enhanced surgical precision by inducing fluorescence in tumor cells, aiding in their complete resection. Several other techniques have been developed in recent years, including intraoperative mass spectrometry methodologies. While each technique boasts unique strengths, they also present potential limitations. As technology and research continue to evolve, these methods are set to undergo further refinement. Collaborative global efforts will be pivotal in driving these advancements, promising a future of improved patient outcomes in brain malignancy management.

A response to 'A commentary on "Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry"'.

A response to 'A commentary on "Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry"'.

A commentary on 'Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry'.

A commentary on 'Detection of cancer cells and tumor margins during colorectal cancer surgery by intraoperative flow cytometry'.

Associations of flow disruptions with patient, staff, and process outcomes: a prospective observational study of robotic-assisted radical prostatectomies

BackgroundTechnological advancements in the operating room (OR) have sparked new challenges for surgical workflow, OR professionals, and patient safety. Disruptive events are frequent across all surgical specialties, but little is known about their effects on patient outcomes and the influence of systemic factors. The aim was to explore the associations of intraoperative flow disruptions (FDs) with patient outcomes, staff workload, and surgery duration.MethodsProspective, single-center, and multi-source study comprising direct and standardized OR observations of urologic surgical procedures, clinical patient outcomes, and staff- and patient-reported outcome data (PROMs; 3-month follow-up). All data were recorded between 01/2020 and 10/2021. FDs were assessed using standardized procedure observations. Linear and logistic regression analyses including multiple system factors were used to explore the effects of FDs on surgical outcomes.Results61 robotic-assisted radical prostatectomy procedures were captured (with 61 patients and 243 staff reports). High rates of FDs were observed; however, our analyses did not show significant relationships with patient complication rates. Equipment- and patient-related FDs were associated with increased staff workload. No association was found between higher rates of FDs and procedure duration.ConclusionsFDs were not related to inferior patient outcomes. Our findings may inform future OR investigations that scrutinize the complex interplay of human, team, process, and technological components that mitigate the effects of FDs during surgery.Graphical abstract

Intraoperative Hemodynamics of Parasylvian Cortical Arteries for Predicting Postoperative Symptomatic Cerebral Hyperperfusion after Direct Revascularization in Patients with Moyamoya Disease: A Preliminary Study.

Objective. The search for methods by which to predict the risks of cerebral hyperperfusion syn-drome (CHS) in adults with moyamoya disease (MMD), including those utilizing new biomarkers, still deserves further research. The objective of this study was to investigate the association between the hemodynamics of parasylvian cortical arteries (PSCAs) and postoperative CHS. Methods. A consecutive number of adults with MMD who had undergone direct bypass between September 2020 and December 2022 were recruited. Intraoperative microvascular doppler ultrasonography (MDU) was performed to evaluate the hemodynamics of PSCAs. The intraoperative flow direction, mean value of velocity (MVV) of recipient artery (RA) and bypass graft were recorded. According to flow direction after bypass, RA was divided into entering sylvian (RA.ES) and leaving sylvian (RA.LS) subtypes. Univariate, multivariate, and ROC analyses of the risk factors for postoperative CHS were performed. Results. A total of 16 (15.09%) cases in 106 consecutive hemispheres (101 patients) sat-isfied the postoperative CHS criteria. According to univariate analysis, advanced Suzuki stage, MVV of RA before bypass, and fold increase of MVV in RA.ES after bypass were significantly associated with postoperative CHS (p < 0.05). Multivariate analysis indicated that left-operated hemisphere (OR (95%CI), 4.58 (1.05-19.97), p = 0.043), advanced Suzuki stage (OR (95%CI), 5.47 (1.99-15.05), p = 0.017), and fold increase of MVV in RA.ES (OR (95%CI), 1.17 (1.06-1.30), p = 0.003) were statistically significantly associated with the occurrence of CHS. The cut-off value of fold increase of MVV in RA.ES was 2.7-fold (p < 0.05). Conclusions. Left-operated hemisphere, advanced Suzuki stage, and postoperative fold increase of MVV in RA.ES were potential risk factors for postoperative CHS. Intraoperative MDU was useful for evaluating hemodynamics and predicting CHS.

Assessment of Gliomas' Grade of Malignancy and Extent of Resection Using Intraoperative Flow Cytometry.

Intraoperative Flow Cytometry (iFC) is a novel technique for the assessment of the grade of malignancy and the diagnosis of tumor type and resection margins during solid tumor surgery. Herein, we set out to analyze the role of iFC in the grading of gliomas and the evaluation of resection margins. iFC uses a fast cell cycle analysis protocol (Ioannina Protocol) that permits the analysis of tissue samples within 5-6 min. Cell cycle analysis evaluated the G0/G1 phase, S-phase, mitosis, and tumor index (S + mitosis phase fraction) and ploidy status. In the current study, we evaluated tumor samples and samples from the peripheral borders from patients with gliomas who underwent surgery over an 8-year period. Eighty-one patients were included in the study. There were sixty-eight glioblastoma cases, five anaplastic astrocytomas, two anaplastic oligodendrogliomas, one pilocytic astrocytoma, three oligodendrogliomas and two diffuse astrocytomas. High-grade gliomas had a significantly higher tumor index than low grade gliomas (median value 22 vs. 7.5, respectively, p = 0.002). Using ROC curve analysis, a cut-off value of 17% in the tumor index could differentiate low- from high-grade gliomas with a 61.4% sensitivity and 100% specificity. All low-grade gliomas were diploid. From the high-grade gliomas, 22 tumors were aneuploid. In glioblastomas, aneuploid tumors had a significantly higher tumor index (p = 0.0018). Twenty-three samples from glioma margins were evaluated. iFC verified the presence of malignant tissue in every case, using histology as the gold standard. iFC constitutes a promising intraoperative technique for glioma grading and resection margin assessment. Comparative studies with additional intraoperative adjuncts are necessary.

The Importance of Perioperative Flow Evaluation and Prevention of Steal Syndrome in Arteriovenous Fistula Surgery Using Transit-Time Flow Measurement

Aim: Our aim is to evaluate the relationship between the survival time of arteriovenous (AV) fistula whose flows are measured with flow meter in patients with chronic renal failure who were operated for AV fistula (AVF) and present the results. Materials and Methods: In our clinic, we evaluated the flow meter measurement results with patency rates and usability after 6 months of AVF in 100 patients who underwent AVF operation due to chronic renal failure. Findings: In February 2012, transit-time flow measurement was put into use in our clinic. The last 50 consecutive patients with the same characteristics before this date constituted the control group (Group A) and the first 50 consecutive patients after this date constituted the study group. Radiocephalic fistula was made the most common (Group A, n = 50; Group B, n = 50). Nondominant upper extremity was selected when planning AVF for patients. First radiocephalic, then brachiocephalic AVF was performed. Fistulas flow was measured with an intraoperative flow meter. Those with bad flow were revised during the operation. Embolectomy was performed in one patient at the 2nd month due to fistula thrombosis, but it was not successful in one patient, and an AVF was opened with a graft. Results: While creating AVF, our aim is to use it effectively for a long time. By evaluating the fistula flows with the flow meter and make an intraoperative revision if necessary we ensure to extend the lifespan of a fistula.

Non-Angry Superficial Draining Veins: A New Technique in Identifying the Extent of Nidus Excision during Cerebral Arteriovenous Malformation Surgery

As essential techniques, intraoperative indocyanine green video angiography (ICG-VA) and FLOW 800 have been widely used in microsurgery for arteriovenous malformations (AVMs). In the present report, we introduced a supplementary technical trick for judging the degree of lesion resection when there were superficial drainage veins. FLOW 800 analysis is used to verify our conjecture. A retrospective analysis of a 33 case cohort treated surgically from June 2020 to September 2022 was conducted and their lesions were removed by superficial drainage veins as a supplementary technical trick and analyzed with FLOW800. In our 33 AVMs, the feeding artery was visualized earlier than the draining vein. Intraoperatively, the T1/2 peak and slope of the draining vein were significantly higher than that of the lesion. However, the maximum fluorescence intensity (MFI) of the draining vein decreased as the procedure progressed (p < 0.001). After reducing the blood flow to the nidus by progressive dissection of the feeding artery, the arteriovenous transit time (AVTT) decreased from 0.64 ± 0.47 s, was prolonged to 2.38 ± 0.52 (p < 0.001), and the MFI and slope of the nidus decreased from the pre-resection 435.42 ± 43.90 AI and 139.77 ± 27.55 AI/s, and decreased to 386.70 ± 48.17 AI and 116.12 ± 17.46 AI/s (p < 0.001). After resection of the nidus, the T1/2 peak of the draining vein increased from 21.42 ± 4.70 s, prolonged to after dissection of the blood feeding artery, 23.07 ± 5.29 s (p = 0.424), and after resection of the lesion, 25.13 ± 5.46 s (p = 0.016), with a slope from 135.79 ± 28.17 AI/s increased to 210.86 ± 59.67 AI/s (p < 0.001). ICG-VA integrated with FLOW 800 is an available method for determining the velocity of superficial drainage veins. Whether the color of the superficial drainage veins on the cortical surface returns to normal can determine whether the lesion is completely resected and can reduce the possibility of residual postoperative lesions.

Intraoperative Flow Cytometry for the Evaluation of Meningioma Grade.

Meningiomas are the most frequent central nervous system tumors in adults. The majority of these tumors are benign. Nevertheless, the intraoperative identification of meningioma grade is important for modifying surgical strategy in order to reduce postoperative complications. Here, we set out to investigate the role of intraoperative flow cytometry for the differentiation of low-grade (grade 1) from high-grade (grade 2-3) meningiomas. The study included 59 patients. Intraoperative flow cytometry analysis was performed using the 'Ioannina Protocol' which evaluates the G0/G1 phase, S-phase, mitosis and tumor index (S + mitosis phase fraction) of a tumor sample. The results are available within 5 min of sample receipt. There were 41 grade 1, 15 grade 2 and 3 grade 3 meningiomas. High-grade meningiomas had significantly higher S-phase fraction, mitosis fraction and tumor index compared to low-grade meningiomas. High-grade meningiomas had significantly lower G0/G1 phase fraction compared to low-grade meningiomas. Thirty-eight tumors were diploids and twenty-one were aneuploids. No significant difference was found between ploidy status and meningioma grade. ROC analysis indicated 11.4% of tumor index as the optimal cutoff value thresholding the discrimination between low- and high-grade meningiomas with 90.2% sensitivity and 72.2% specificity. In conclusion, intraoperative flow cytometry permits the detection of high-grade meningiomas within 5 min. Thus, surgeons may modify tumor removal strategy.

Assessment of glioma grade of malignancy and extent of resection using intraoperative flow cytometry

Assessment of glioma grade of malignancy and extent of resection using intraoperative flow cytometry

Importance of Flow Waveform and Flow Volume as Prognostic Indicators for the Patency of Infra-Inguinal Autologous Vein Bypass

To investigate the association of the intraoperative flow waveform and the flow volume with the graft prognosis of infrainguinal vein bypass. Retrospective study. Intraoperative flowmetry was performed for infrainguinal autologous vein bypass between 2011 and 2020. Flow waveforms were classified into type 0-IV according to the Kyushu University (KU) classification. The patients (n=340) were divided into three groups based on the flow waveform predicting the graft patency: type 0/I (long patency), type II (no early occlusion but late occlusion possible) and type III/IV (early occlusion). The graft occlusion rates of popliteal artery bypass (PAB) and infrapopliteal artery bypass (IPAB) within 30 days after surgery were compared between type 0/I+II and type III/IV groups, while the mid-term graft patency rates were compared between type 0/I and type II groups. Additionally, a multivariate analysis was performed to identify independent risk factors for early and late graft occlusion. The early graft occlusion rates of type 0/I+II and type III/IV groups were 3.9 % and 0%, respectively, (p=1.00) for PAB and 5.3 % and 46.2% respectively, (p<.001) for IPAB. The 2 years' primary patency rates of type 0/I and type II groups were 91% and 75%, respectively, (p= .030) for PAB and 58% and 63%, respectively, (p= .72) for IPAB. An independent risk factor for early occlusion was none in PAB and flow waveform (type IV) in IPAB. An independent risk factor in PAB was flow waveform (type II), end-stage renal disease, and dual antiplatelet use and those in IPAB were older age, female sex, lower flow volume, and iterative bypass for primary patency loss. Intraoperative flowmetry is useful for predicting the graft prognosis in infrainguinal vein bypass and its significance depends on the distal target artery.

Accurate Characterization of Bladder Cancer Cells with Intraoperative Flow Cytometry.

Bladder cancer represents a major health issue. Transurethral resection is the first line treatment and an accurate assessment of tumor margins might warrant complete tumor removal. Genomic instability and proliferative potential are common hallmarks of cancer cells. We have previously demonstrated the utility of intraoperative flow cytometry (iFC), a next-generation margin evaluation methodology for assessment of DNA content, in the detection of several types of malignancy. In the current study we investigated the possible value of iFC in the characterization of bladder cancer during surgery. Samples from a population of 52 people with urothelial cancer were included in the study. The total time for iFC evaluation is 3-5 min per sample and included a two-step analysis, including DNA-index and Tumor-index calculation. First, DNA-index calculation revealed 24 hyperploid and one hypoploid tumor. Second, cell cycle analysis and Tumor-index calculation revealed that tumor samples are distinguished from normal cells based on their significantly higher proliferative potential. The standard for iFC evaluation was pathology assessment and revealed that our protocol exhibits an accuracy of 98% in defining the presence of cancer cells in a given sample. Our results support the further assessment of iFC value towards its use as a novel malignancy evaluation tool in transurethral resections.