Computer-aided quality assessment of endoscopist competence during colonoscopy: a systematic review.

BACKGROUND AND AIMS: Endoscopists' competence can vary widely, as shown in the variation in the adenoma detection rate (ADR). Computer-aided quality assessment (CAQ) can automatically assess performance during individual procedures. In this review we identified and described different CAQ systems for colonoscopy. METHODS: A systematic review of the literature was done using MEDLINE, EMBASE, and Scopus based on 3 blocks of terms according to the inclusion criteria: colonoscopy, competence assessment, and automatic evaluation. Articles were systematically reviewed by 2 reviewers, first by abstract and then in full text. The methodological quality was assessed using the Medical Education Research Study Quality Instrument (MERSQI). RESULTS: Of 12,575 identified studies, 6831 remained after removal of duplicates and 6806 did not pass the eligibility criteria and were excluded, leaving 25 studies, of which 13 studies were included in the final analysis. Five categories of CAQ systems were identified: withdrawal speedometer (7 studies), endoscope movement analysis (3 studies), effective withdrawal time (1 study), fold examination quality (1 study), and visual gaze pattern (1 study). The withdrawal speedometer was the only CAQ system that tested its feedback by examining changes in ADR. Three studies observed an improvement in ADR, and 2 studies did not. The methodological quality of the studies was high (mean MERSQI, 15.2 points; maximum, 18 points). CONCLUSIONS: Thirteen studies developed or tested CAQ systems, most frequently by correlating it to the ADR. Only 5 studies tested feedback by implementing the CAQ system. A meta-analysis was impossible because of the heterogeneous study designs, and more studies are warranted.

Developing a phantom for simulating robotic-assisted complete mesocolic excision using 3D printing and medical imaging.

BACKGROUND: Robotic-assisted complete mesocolic excision is an advanced procedure mainly because of the great variability in anatomy. Phantoms can be used for simulation-based training and assessment of competency when learning new surgical procedures. However, no phantoms for robotic complete mesocolic excision have previously been described. This study aimed to develop an anatomically true-to-life phantom, which can be used for training with a robotic system situated in the clinical setting and can be used for the assessment of surgical competency. METHODS: Established pathology and surgical assessment tools for complete mesocolic excision and specimens were used for the phantom development. Each assessment item was translated into an engineering development task and evaluated for relevance. Anatomical realism was obtained by extracting relevant organs from preoperative patient scans and 3D printing casting moulds for each organ. Each element of the phantom was evaluated by two experienced complete mesocolic excision surgeons without influencing each other's answers and their feedback was used in an iterative process of prototype development and testing. RESULTS: It was possible to integrate 35 out of 48 procedure-specific items from the surgical assessment tool and all elements from the pathological evaluation tool. By adding fluorophores to the mesocolic tissue, we developed an easy way to assess the integrity of the mesocolon using ultraviolet light. The phantom was built using silicone, is easy to store, and can be used in robotic systems designated for patient procedures as it does not contain animal-derived parts. CONCLUSIONS: The newly developed phantom could be used for training and competency assessment for robotic-assisted complete mesocolic excision surgery in a simulated setting.

Laser Speckle Contrast Imaging-based diagnosis of severe mesenteric traction syndrome: Hemodynamics and prostacyclin - A prospective cohort study.

BRIEF ABSTRACT: Today, the diagnosis and grading of mesenteric traction syndrome relies on a subjective assessment of facial flushing. However, this method has several limitations. In this study, Laser Speckle Contrast Imaging and a predefined cut-off value are assessed and validated for the objective identification of severe mesenteric traction syndrome. BACKGROUND: Severe mesenteric traction syndrome (MTS) is associated with increased postoperative morbidity. The diagnosis is based on an assessment of the developed facial flushing. Today this is performed subjectively, as no objective method exists. One possible objective method is Laser Speckle Contrast Imaging (LSCI), which has been used to show significantly higher facial skin blood flow in patients developing severe MTS. Using these data, a cut-off value has been identified. This study aimed to validate our predefined LSCI cut-off value for identifying severe MTS. METHODS: A prospective cohort study was performed on patients planned for open esophagectomy or pancreatic surgery from March 2021 to April 2022. All patients underwent continuous measurement of forehead skin blood flow using LSCI during the first hour of surgery. Using the predefined cut-off value, the severity of MTS was graded. In addition, blood samples for prostacyclin (PGI2) analysis and hemodynamics were collected at predefined time points to validate the cut-off value. MAIN RESULTS: Sixty patients were included in the study. Using our predefined LSCI cut-off value, 21 (35 %) patients were identified as developing severe MTS. These patients were found to have higher concentrations of 6-Keto-PGFaα (p = 0.002), lower SVR (p < 0.001), lower MAP (p = 0.004), and higher CO (p < 0.001) 15 min into surgery, as compared with patients not developing severe MTS. CONCLUSION: This study validated our LSCI cut-off value for the objective identification of severe MTS patients as this group developed increased concentrations of PGI2 and more pronounced hemodynamic alterations compared with patients not developing severe MTS.

Intraoperative near-infrared lymphography with indocyanine green may aid lymph node dissection during robot-assisted resection of gastroesophageal junction cancer.

BACKGROUND: Adequate lymphadenectomy during gastroesophageal junction (GEJ) cancer resection is essential, because lymph node (LN) metastasis correlates with increased recurrence risk. Fluorescence lymphography with indocyanine green (ICG) has been used for LN mapping in several surgical specialties; however, reports on GEJ cancer are lacking. Therefore, we investigated whether intraoperative ICG lymphography could facilitate LN harvest during robot-assisted resection of GEJ cancer. METHODS: Patients scheduled for robot-assisted resection of GEJ cancer were included, and outcomes were compared with historical controls. After intraoperative endoscopic submucosal ICG injection, standard D1 + LN dissection was performed under white light. Then, near-infrared (NIR) fluorescence imaging was activated, and each LN dissection area was re-examined. Any tissue within the D1 + field exhibiting distinctly increased ICG fluorescence compared with background tissue was dissected and sent for pathology review. RESULTS: We included 70 patients between June 2020 and October 2021. Three cases were aborted due to disseminated disease, and two were converted to open resection and excluded from the analysis. Additional tissue was dissected after NIR review in 34 of 65 (52%) patients. We dissected 43 fluorescent tissue samples, and after pathology review, 30 were confirmed LNs; none were metastatic. The median number of LNs harvested per patient (34, interquartile range [IQR] = 26-44) was not significantly different from that harvested from historical controls (32, IQR = 24-45; p = 0.92), nor were there any differences between these two groups in the duration of surgery, intraoperative blood loss, or comprehensive complication scores (p = 0.12, p = 0.46, and p = 0.41, respectively). CONCLUSIONS: Intraoperative NIR lymphography with ICG may aid LN detection during robot-assisted resection of GEJ cancer without increasing surgical risk. Although NIR lymphography may facilitate LN dissection, none of the LN removed after the NIR review was metastatic. Hence, it remains uncertain whether NIR lymphography will improve oncological outcomes.

Acquisition and usage of robotic surgical data for machine learning analysis.

BACKGROUND: The increasing use of robot-assisted surgery (RAS) has led to the need for new methods of assessing whether new surgeons are qualified to perform RAS, without the resource-demanding process of having expert surgeons do the assessment. Computer-based automation and artificial intelligence (AI) are seen as promising alternatives to expert-based surgical assessment. However, no standard protocols or methods for preparing data and implementing AI are available for clinicians. This may be among the reasons for the impediment to the use of AI in the clinical setting. METHOD: We tested our method on porcine models with both the da Vinci Si and the da Vinci Xi. We sought to capture raw video data from the surgical robots and 3D movement data from the surgeons and prepared the data for the use in AI by a structured guide to acquire and prepare video data using the following steps: 'Capturing image data from the surgical robot', 'Extracting event data', 'Capturing movement data of the surgeon', 'Annotation of image data'. RESULTS: 15 participant (11 novices and 4 experienced) performed 10 different intraabdominal RAS procedures. Using this method we captured 188 videos (94 from the surgical robot, and 94 corresponding movement videos of the surgeons' arms and hands). Event data, movement data, and labels were extracted from the raw material and prepared for use in AI. CONCLUSION: With our described methods, we could collect, prepare, and annotate images, events, and motion data from surgical robotic systems in preparation for its use in AI.

Anastomotic perfusion assessment with indocyanine green in robot-assisted low-anterior resection, a multicenter study of interobserver variation.

BACKGROUND: Securing sufficient blood perfusion to the anastomotic area after low-anterior resection is a crucial factor in preventing anastomotic leakage (AL). Intra-operative indocyanine green fluorescent imaging (ICG-FI) has been suggested as a tool to assess perfusion. However, knowledge of inter-observer variation among surgeons in the interpretation of ICG-FI is sparse. Our primary objective was to evaluate inter-observer variation among surgeons in the interpretation of bowel blood-perfusion assessed visually by ICG-FI. Our secondary objective was to compare the results both from the visual assessment of ICG and from computer-based quantitative analyses of ICG-FI between patients with and without the development of AL. METHOD: A multicenter study, including patients undergoing robot-assisted low anterior resection with stapled anastomosis. ICG-FI was evaluated visually by the surgeon intra-operatively. Postoperatively, recorded videos were anonymized and exchanged between centers for inter-observer evaluation. Time to visibility (TTV), time to maximum visibility (TMV), and time to wash-out (TWO) were visually assessed. In addition, the ICG-FI video-recordings were analyzed using validated pixel analysis software to quantify blood perfusion. RESULTS: Fifty-five patients were included, and five developed clinical AL. Bland-Altman plots (BA plots) demonstrated wide inter-observer variation for visually assessed fluorescence on all parameters (TTV, TMV, and TWO). Comparing leak-group with no-leak group, we found no significant differences for TTV: Hazard Ratio; HR = 0.82 (CI 0.32; 2.08), TMV: HR = 0.62 (CI 0.24; 1.59), or TWO: HR = 1.11 (CI 0.40; 3.11). In the quantitative pixel analysis, a lower slope of the fluorescence time-curve was found in patients with a subsequent leak: median 0.08 (0.07;0.10) compared with non-leak patients: median 0.13 (0.10;0.17) (p = 0.04). CONCLUSION: The surgeon's visual assessment of the ICG-FI demonstrated wide inter-observer variation, there were no differences between patients with and without AL. However, quantitative pixel analysis showed a significant difference between groups. TRIAL REGISTRATION: ClinicalTrials.gov Identifier: NCT04766060.

Preparing for Reality: A Randomized Trial on Immersive Virtual Reality for Bronchoscopy Training.

BACKGROUND: Bronchoscopy is an essential procedure in the diagnosis and treatment of pulmonary diseases. However, the literature suggests that distractions affect the quality of bronchoscopy and affect inexperienced doctors more than experienced. OBJECTIVES: The objective of the study was as follows: does simulation-based bronchoscopy training with immersive virtual reality (iVR) improve the doctors' ability to handle distractions and thereby increase the quality, measured in procedure time, structured progression score, diagnostic completeness (%), and hand motor movements of a diagnostic bronchoscopy in a simulated scenario. Exploratory outcomes were heart rate variability and a cognitive load questionnaire (Surg-TLX). METHODS: Participants were randomized. The intervention group practiced in an iVR environment with a head-mounted display (HMD) while using the bronchoscopy simulator, while the control group trained without the HMD. Both groups were tested in the iVR environment using a scenario with distractions. RESULTS: 34 participants completed the trial. The intervention group scored significantly higher in diagnostic completeness (100 i.q.r. 100-100 vs. 94 i.q.r. 89-100, p value = 0.03) and structured progress (16 i.q.r. 15-18 vs. 12 i.q.r. 11-15, p value 0.03) but not in procedure time (367 s standard deviation [SD] 149 vs. 445 s SD 219, p value = 0.06) or hand motor movements (-1.02 i.q.r. -1.03-[-1.02] versus -0.98 i.q.r. -1.02-[-0.98], p value = 0.27). The control group had a tendency toward a lower heart rate variability (5.76 i.q.r. 3.77-9.06 vs. 4.12 i.q.r. 2.68-6.27, p = 0.25). There was no significant difference in total Surg-TLX points between the two groups. CONCLUSION: iVR simulation training increases the quality of diagnostic bronchoscopy in a simulated scenario with distractions compared with conventional simulation-based training.

Using Virtual Reality Head-Mounted Displays to Assess Skills in Emergency Medicine: Validity Study.

BACKGROUND: Many junior doctors must prepare to manage acutely ill patients in the emergency department. The setting is often stressful, and urgent treatment decisions are needed. Overlooking symptoms and making wrong choices may lead to substantial patient morbidity or death, and it is essential to ensure that junior doctors are competent. Virtual reality (VR) software can provide standardized and unbiased assessment, but solid validity evidence is necessary before implementation. OBJECTIVE: This study aimed to gather validity evidence for using 360-degree VR videos with integrated multiple-choice questions (MCQs) to assess emergency medicine skills. METHODS: Five full-scale emergency medicine scenarios were recorded with a 360-degree video camera, and MCQs were integrated into the scenarios to be played in a head-mounted display. We invited 3 groups of medical students with different experience levels to participate: first- to third-year medical students (novice group), last-year medical students without emergency medicine training (intermediate group), and last-year medical students with completed emergency medicine training (experienced group). Each participant's total test score was calculated based on the number of correct MCQ answers (maximum score of 28), and the groups' mean scores were compared. The participants rated their experienced presence in emergency scenarios using the Igroup Presence Questionnaire (IPQ) and their cognitive workload with the National Aeronautics and Space Administration Task Load Index (NASA-TLX). RESULTS: We included 61 medical students from December 2020 to December 2021. The experienced group had significantly higher mean scores than the intermediate group (23 vs 20; P=.04), and the intermediate group had significantly higher scores than the novice group (20 vs 14; P<.001). The contrasting groups' standard-setting method established a pass-or-fail score of 19 points (68% of the maximum possible score of 28). Interscenario reliability was high, with a Cronbach α of 0.82. The participants experienced the VR scenarios with a high degree of presence with an IPQ score of 5.83 (on a scale from 1-7), and the task was shown to be mentally demanding with a NASA-TLX score of 13.30 (on a scale from 1-21). CONCLUSIONS: This study provides validity evidence to support using 360-degree VR scenarios to assess emergency medicine skills. The students evaluated the VR experience as mentally demanding with a high degree of presence, suggesting that VR is a promising new technology for emergency medicine skills assessment.

The fundamentals of Artificial Intelligence in medical education research: AMEE Guide No. 156.

The use of Artificial Intelligence (AI) in medical education has the potential to facilitate complicated tasks and improve efficiency. For example, AI could help automate assessment of written responses, or provide feedback on medical image interpretations with excellent reliability. While applications of AI in learning, instruction, and assessment are growing, further exploration is still required. There exist few conceptual or methodological guides for medical educators wishing to evaluate or engage in AI research. In this guide, we aim to: 1) describe practical considerations involved in reading and conducting studies in medical education using AI, 2) define basic terminology and 3) identify which medical education problems and data are ideally-suited for using AI.

Physiological effects of temperature on Greenland halibut Reinhardtius hippoglossoides shows high vulnerability of Arctic stenotherms to global warming.

Global warming affects the metabolism of ectothermic aquatic breathers forcing them to migrate and undergo high-latitudinal distribution shifts to circumvent the temperature-induced mismatch between increased metabolic demand and reduced water oxygen availability. Here the authors examined the effects of temperature on oxygen consumption rates in an Arctic stenotherm, the Greenland halibut Reinhardtius hippoglossoides, and calculated the optimal temperature for maximum aerobic scope, AS(Topt,AS ), which was found to be 2.44°C. They also investigated cardiac performance as limiting the oxygen transport chain at high temperatures by measuring maximum heart rate (fHmax ) over acute temperature increases and found various metrics related to fHmax to be at least 3.2°C higher than Topt,AS . The authors' measured Topt,AS closely reflected in situ temperature occurrences of Greenland halibut from long-term tagging studies, showing that AS of the species is adapted to its habitat temperature, and is thus a good proxy for the species' sensitivity to environmental warming. The authors did not find a close connection between fHmax and Topt,AS , suggesting that cardiac performance is not limiting for the oxygen transport chain at high temperatures in this particular Arctic stenotherm. The authors' estimate of the thermal envelope for AS of Greenland halibut was from -1.89 to 8.07°C, which is exceptionally narrow compared to most other species of fish. As ocean temperatures increase most rapidly in the Arctic in response to climate change, and species in these areas have limited possibility for further poleward-range shifts, these results suggest potential severe effects of global warming on Arctic stenotherms, such as the Greenland halibut. The considerable economic importance of the species raises concerns for future fisheries and species conservation of Arctic stenotherms in the Northern Hemisphere.

Colonoscope retraction technique and predicting adenoma detection rate: a multicenter study.

BACKGROUND AND AIMS: The success of preventing colorectal cancer relies on the expertise of the colonoscopists. Studies suggest that the retraction technique is a powerful indicator of expertise in distinguishing endoscopists with various adenoma detection rates (ADRs). We aimed to develop a retraction technique score and explore the correlation between endoscopists' retraction technique and their ADRs. METHODS: In a prospective, multicenter study, 8 colonoscopist nurses and physicians with various ADRs were included. Data from patients admitted for a colonoscopy, as part of the Danish nationwide screening program, were gathered directly from the Olympus ScopeGuide system (UPD-3; Olympus Optical, Tokyo, Japan) providing XYZ-coordinates from the coils along the length of the colonoscope. Motor skill measures were developed based on tip retraction, retraction efficiency, and retraction distance. The principal component analysis was used to study the association among the 3 measures and the historical ADR to create a combined score, the colonoscopy retraction score (CoRS). RESULTS: Three hundred thirty-three recordings were analyzed. We demonstrated a significant and strong correlation between CoRS and ADR (.90, P < .01). Conversely, withdrawal time did not correlate significantly with ADR (.33, P = .42). In procedures without polypectomies or biopsy sampling, a significant and strong correlation was found between CoRS and ADR (.88, P < .01) and between withdrawal time and ADR (.75, P = .03). CONCLUSIONS: This study presents a novel, real-time computerized and unbiased assessment tool for colonoscopy withdrawal. CoRS strongly correlated with ADR with and without therapeutic interventions during withdrawal and could be used to ensure quality instead of minimal withdrawal time. (Clinical trial registration number: NCT03587935.).

Genetic variants associated with two major bovine milk fatty acids offer opportunities to breed for altered milk fat composition.

BACKGROUND: Although bovine milk is regarded as healthy and nutritious, its high content of saturated fatty acids (FA) may be harmful to cardiovascular health. Palmitic acid (C16:0) is the predominant saturated FA in milk with adverse health effects that could be countered by substituting it with higher levels of unsaturated FA, such as oleic acid (C18:1cis-9). In this work, we performed genome-wide association analyses for milk fatty acids predicted from FTIR spectroscopy data using 1811 Norwegian Red cattle genotyped and imputed to a high-density 777k single nucleotide polymorphism (SNP)-array. In a follow-up analysis, we used imputed whole-genome sequence data to detect genetic variants that are involved in FTIR-predicted levels of C16:0 and C18:1cis-9 and explore the transcript profile and protein level of candidate genes. RESULTS: Genome-wise significant associations were detected for C16:0 on Bos taurus (BTA) autosomes 11, 16 and 27, and for C18:1cis-9 on BTA5, 13 and 19. Closer examination of a significant locus on BTA11 identified the PAEP gene, which encodes the milk protein ß-lactoglobulin, as a particularly attractive positional candidate gene. At this locus, we discovered a tightly linked cluster of genetic variants in coding and regulatory sequences that have opposing effects on the levels of C16:0 and C18:1cis-9. The favourable haplotype, linked to reduced levels of C16:0 and increased levels of C18:1cis-9 was also associated with a marked reduction in PAEP expression and ß-lactoglobulin protein levels. ß-lactoglobulin is the most abundant whey protein in milk and lower levels are associated with important dairy production parameters such as improved cheese yield. CONCLUSIONS: The genetic variants detected in this study may be used in breeding to produce milk with an improved FA health-profile and enhanced cheese-making properties.

Quantitative fluorescence angiography aids novice and experienced surgeons in performing intestinal resection in well-perfused tissue.

BACKGROUND: Anastomotic leakage (AL) after gastrointestinal resection is a devastating complication with huge consequences for the patient. As AL is associated with poor blood supply, tools for objective assessment of perfusion are in high demand. Indocyanine green angiography (ICG-FA) and quantitative analysis of ICG-FA (q-ICG) seem promising. This study aimed to investigate whether ICG-FA and q-ICG could improve perfusion assessment performed by surgeons of different experience levels. METHODS: Thirteen small bowel segments with a varying degree of devascularization, including two healthy sham segments, were constructed in a porcine model. We recruited students, residents, and surgeons to perform perfusion assessment of the segments in white light (WL), with ICG-FA, and after q-ICG, all blinded to the degree of devascularization. RESULTS: Forty-five participants fulfilled the study (18 novices, 12 intermediates, and 15 experienced). ICG and q-ICG helped the novices correctly detect the healthy bowel segments to experienced surgeons' level. ICG and q-ICG also helped novice surgeons to perform safer resections in healthy tissue compared with normal WL. The relative risk (RR) of leaving ischemic tissue in WL and ICG compared with q-ICG, even for experienced surgeons was substantial, intermediates (RR = 8.9, CI95% [4.0;20] and RR = 6.2, CI95% [2.7;14.1]), and experienced (RR = 4.7, CI95% [2.6;8.7] and RR = 4.0, CI95% [2.1;7.5]). CONCLUSION: Q-ICG seems to guide surgeons, regardless of experience level, to safely perform resection in healthy tissue, compared with standard WL. Future research should focus on this novel tool's clinical impact.

Dynamics of circulating dendritic cells and cytokines after kidney transplantation-No effect of remote ischaemic conditioning.

Inflammation resulting from ischaemia/reperfusion injury can cause kidney graft dysfunction, increase the risk of delayed graft function and possibly reduce long-term graft survival. Remote ischaemic conditioning may protect against ischaemia/reperfusion injury and mitigate the immunological response to the graft. We investigated the immunological effects of remote ischaemic conditioning on kidney transplantation from deceased donors in the randomized CONTEXT study. Three circulating dendritic cell (DC) subtypes identified in peripheral blood from kidney transplant recipients [myeloid DCs, plasmacytoid DCs and immunoglobulin-like transcript (ILT)3+ DCs] were measured at baseline, days 1, 3 and 5 and 1 and 3 months after transplantation. We also quantified 21 cytokines at baseline, days 1 and 5 and 3 months after transplantation. Neither DC counts nor cytokine levels differed between patients receiving remote ischaemic conditioning and controls; however, several parameters exhibited dynamic and parallel alterations in the two groups over time, reflecting the immunological response to the kidney transplantation and immunosuppression.

Quantitative fluorescence angiography detects dynamic changes in gastric perfusion.

INTRODUCTION: The use of Indocyanine green (ICG) fluorescence angiography (ICG-FA) is an applied method to assess visceral perfusion during surgical procedures worldwide. Further development has entailed quantification of the fluorescence signal; however, whether quantified ICG-FA can detect intraoperative changes in perfusion after hemorrhage has not been investigated previously. In this study, we investigated whether a quantification method, developed and validated in our department (q-ICG), could detect changes in gastric perfusion induced by hemorrhage and resuscitation. METHODS: Ten pigs were included in the study. Specific regions of interest of the stomach were chosen, and three q-ICG measurements of gastric perfusion obtained: 20 min after completion of the laparoscopic setup (baseline), after reducing the circulating blood volume by 30%, and after reinfusion of the withdrawn blood volume. Hemodynamic variables were recorded, and blood samples were collected every 10 min during the procedure. RESULTS: The reduction in blood volume generated decreased gastric perfusion (q-ICG) from baseline (p = 0.023), and gastric perfusion subsequently increased (p < 0.001) after the reintroduction of the withdrawn blood volume. Cardiac output (CO) and mean arterial blood pressure (MAP) shifted correspondingly and the gastric perfusion correlated to CO (r = 0.575, p = 0.001) and MAP (r = 0.436, p = 0.018). CONCLUSION: We present a novel study showing that the q-ICG method can detect dynamic changes in local tissue perfusion induced by hemorrhage and resuscitation. As regional gastrointestinal perfusion may be significantly reduced, while hemodynamic variables such as MAP or heart rate remain stable, q-ICG may provide an objective, non-invasive method for detecting regional early ischemia, strengthening surgical decision making.

Automatic and Objective Assessment of Motor Skills Performance in Flexible Bronchoscopy.

BACKGROUND: Motor skills have been identified as a useful measure to evaluate competency in bronchoscopy. However, no automatic assessment system of motor skills with a clear pass/fail criterion in flexible bronchoscopy exists. OBJECTIVES: The objective of the study was to develop an objective and automatic measure of motor skills in bronchoscopy and set a pass/fail criterion. METHODS: Participants conducted 3 bronchoscopies each in a simulated setting. They were equipped with a Myo Armband that measured lower arm movements through an inertial measurement unit, and hand and finger motions through electromyography sensors. These measures were composed into an objective and automatic composite score of motor skills, the motor bronchoscopy skills score (MoBSS). RESULTS: Twelve novices, eleven intermediates, and ten expert bronchoscopy operators participated, resulting in 99 procedures available for assessment. MoBSS was correlated with a higher diagnostic completeness (Pearson's correlation, r = 0.43, p < 0.001) and a lower procedure time (Pearson's correlation, r = -0.90, p < 0.001). MoBSS was able to differentiate operator performance based on the experience level (one-way ANOVA, p < 0.001). Using the contrasting groups' method, a passing score of -0.08 MoBSS was defined that failed 30/36 (83%) novice, 5/33 (15%) intermediate, and 1/30 (3%) expert procedures. CONCLUSIONS: MoBSS can be used as an automatic and unbiased assessment tool for motor skills performance in flexible bronchoscopy. MoBSS has the potential to generate automatic feedback to help guide trainees toward expert performance.

Characterization of Lung Tumors that the Pulmonologist can Biopsy from the Esophagus with Endosonography (EUS-B-FNA).

BACKGROUND: According to guidelines, it is possible to biopsy lung tumors "immediately adjacent to the esophagus" with EUS-B-FNA. However, it is unknown what "immediately adjacent" exactly means. OBJECTIVE: to investigate the possibility of achieving EUS-B-FNA biopsies from a lung tumor depending on the distance from the esophagus and to establish the maximal allowable distance between the tumor and the esophagus. METHODS: In a prospective observational study, we included patients with a lung tumor located maximum 6 cm from the esophagus and indication of EUS-B-FNA from the tumor. The tumors were of different sizes. In a plot presenting the tumor size-distance relationship in cases with (biopsy) versus without (non-biopsy) successful EUS-B-FNA, a separation line representing the threshold between the groups were identified and a biopsy-index equation established. The maximal tumor-size corrected distance (TSCD) was calculated using the residuals to the separation line. RESULTS: In total, 70 patients were included. EUS-B-FNA from the lung tumor was possible in 46 patients. All tumors with a distance from the esophagus below 19 mm could be biopsied. The maximal allowable esophagus-tumor distance depended on tumor size. From the separation line, a biopsy-index equation was established with the sensitivity of 93.5%, a specificity of 100%, and total accuracy of 95.7%. The TSCD was 31 mm (sensitivity: 95.7%, specificity 75.0%, and accuracy: 88.6%). CONCLUSION: We established a biopsy-index equation to predict the achievability of a lung tumor using EUS-B-FNA depending on distance to esophagus and tumor size. A general maximal TSCD was 31 mm.

Quantification of fluorescence angiography: Toward a reliable intraoperative assessment of tissue perfusion - A narrative review.

BACKGROUND: Accurate intraoperative assessments of tissue perfusion are essential in all forms of surgery. As traditional methods of perfusion assessments are not available during minimally invasive surgery, novel methods are required. Here, fluorescence angiography with indocyanine green has shown promising results. However, to secure objective and reproducible assessments, quantification of the fluorescent signal is essential (Q-ICG). This narrative review aims to provide an overview of the current status and applicability of Q-ICG for intraoperative perfusion assessment. RESULTS: Both commercial and custom Q-ICG software solutions are available for intraoperative use; however, most studies on Q-ICG have performed post-operative analyses. Q-ICG can be divided into inflow parameters (ttp, t0, slope, and T1/2max) and intensity parameters (Fmax, PI, and DR). The intensity parameters appear unreliable in clinical settings. In comparison, inflow parameters, mainly slope, and T1/2max have had superior clinical performance. CONCLUSION: Intraoperative Q-ICG is clinically available; however, only feasibility studies have been performed, rendering an excellent usability score. Q-ICG in a post-operative setting could detect changes in perfusion following a range of interventions and reflect clinical endpoints, but only if based on inflow parameters. Thus, future studies should include the methodology outlined in this review, emphasizing the use of inflow parameters (slope or T1/2max), a mass-adjusted ICG dosing, and a fixed camera position.

Time to maximum indocyanine green fluorescence of gastric sentinel lymph nodes and feasibility of combined indocyanine green/sodium fluorescein gastric lymphography.

PURPOSE: Indocyanine green (ICG) and sodium fluorescein (SF) are fluorescent dyes used for sentinel lymph node mapping. In oncological gastric surgery, ICG lymphography has increased the number of resected lymph nodes. However, the optimal time to administer ICG is unclear, and both preoperative and intraoperative injections have been practised. As dye spillage will diminish lymphogram visibility, a second dye with different excitation and emission spectra may present a clinical alternative. We measured the time until maximum ICG fluorescence of gastric sentinel lymph nodes and investigated the feasibility of combined lymphography with two fluorescent dyes: ICG and SF. METHODS: Ten Danish Landrace/Yorkshire pigs were used in this study. After completion of the laparoscopic setup, ICG and then SF were endoscopically injected into the gastric submucosa. Lymphograms for both dyes were recorded, and the time until maximum ICG sentinel lymph node fluorescence was determined. RESULTS: The mean time until maximum ICG fluorescence of gastric sentinel lymph nodes was 50 s (± 12.5), and the fluorescent signal then remained stable until the end of the recorded period (45 min). A lymphogram showing both ICG and SF was acquired for eight of the ten pigs. CONCLUSIONS: Because of the short time until maximum ICG fluorescence of sentinel lymph nodes, intraoperative injections could be a sufficient alternative to preoperative injections for oncological gastric surgery. Combined ICG and SF lymphography was feasible and resulted in clear lymphograms with no interference between the two dyes. The ability to use multiple dyes during a surgical procedure offers the exciting prospect of simultaneously assessing perfusion and performing fluorescence lymphography.

Optimizing quantitative fluorescence angiography for visceral perfusion assessment.

BACKGROUND: Compromised tissue perfusion is a significant risk factor for anastomotic leakage after intestinal resection, leading to prolonged hospitalization, risk of recurrence after oncologic resection, and reduced survival. Thus, a tool reducing the risk of leakage is highly warranted. Quantitative indocyanine green angiography (Q-ICG) is a new method that provides surgeons with an objective evaluation of tissue perfusion. In this systematic review, we aimed to determine the optimal methodology for performing Q-ICG. METHOD: A comprehensive search of the literature was performed following the PRISMA guidelines. The following databases were searched: PubMed, Embase, Scopus, and Cochrane. We included all clinical studies that performed Q-ICG to assess visceral perfusion during gastrointestinal surgery. Bias assessment was performed with the Newcastle Ottawa Scale. RESULTS: A total of 1216 studies were screened, and finally, 13 studies were included. The studies found that intensity parameters (maximum intensity and relative maximum intensity) could not identify patients with anastomotic leakage. In contrast, the inflow parameters (time-to-peak, slope, and t1/2max) were significantly associated with anastomotic leakage. Only two studies performed intraoperative Q-ICG while the rest performed Q-ICG retrospectively based on video recordings. Studies were heterogeneous in design, Q-ICG parameters, and patient populations. No randomized studies were found, and the level of evidence was generally found to be low to moderate. CONCLUSION: The results, while heterogenous, all seem to point in the same direction. Fluorescence intensity parameters are unstable and do not reflect clinical endpoints. Instead, inflow parameters are resilient in a clinical setting and superior at reflecting clinical endpoints.