Yellow Arrow Research Articles

In-vivo mapping of human polymorphic ventricular tachycardia in Brugada syndrome

Abstract Background/introduction Brugada syndrome (BrS) is associated with ventricular fibrillation (VF) and polymorphic ventricular tachycardia (PMVT). Different mechanisms have been described for human PMVT, including epicardial drifting of rotational activity before stabilization on the apex. Purpose The aim of this study is mapping human PMVT mechanisms in BrS with ECG imaging (ECGI) in-vivo. Methods All BrS patients, were prospectively enrolled between 1992 and 2022. Inclusion criteria for the study were: 1) BrS diagnosis; 2) PMVT mapped with ECGI during thoracoscopic epicardial right ventricle outflow tract ablation. PMVT was adjudicated if a changing QRS pattern was present. Phase mapping was performed for each PMVT. All maps were imported on a dedicated software and analyzed offline. Left anterior descending coronary artery was added, based on CT scan reconstruction as a reference for the interventricular septum (in grey in Figure 1). Phase maps were performed using the Hilbert transform on detrended signals and the phases of wavefront propagation were color-coded. Rotational activity was defined as a continuous progression of phase from -π to +π around a phase singularity point. Focal activity was defined as a wavefront that appears de novo, without arising from another wavefront and spreading from its origin. Results A total of 21 BrS patients with VF were analyzed and 2 patients (9.5%) were found with PMVT. A total of 2 episodes of PMVT were mapped (one for each BrS patient) with a duration of 2.9 s and 1.3 s, respectively. Both PMVT had spontaneous initiation and termination. The mean number of rotational activities was 2.45 ± 0.07, with a mean of 2.9 ± 0.71 rotations on the apex and 0.8 ± 1.13 rotations on the septum. No other rotational activity was observed. There were 2 and 1 focal activities on the septum, respectively. No other focal activity was observed. The phase mapping of both PMVT episodes was consistent with the mechanism shown in Figure 1. In the first phase of PMVT (negative QRS) a stable rotor (white arrow) is found over ventricular apex (Figure 1, Panels A-D). In Figure 1, Panel E a septal activity appears (yellow arrow). The reduction of QRS voltage is secondary to a fusion between septal (yellow arrow) and apical (white arrow) rotational activities (Figure 1, Panels F-G). In the second phase of PMVT (positive QRS) a stable focal activity (yellow arrow) is found over the ventricular septum (Figure 1, Panels H-J). Conclusion In patients with BrS, change in the QRS pattern during PMVT is secondary to a fusion between rotational septal and apical activities.Figure 1

Using attentional guidance methods in virtual reality laboratories reduces students’ cognitive load and improves their academic performance

Learning in virtual reality laboratories (VR labs) has become an important method in experimental teaching but can increase individuals’ cognitive load compared with traditional laboratories. This study analysed the effect of introducing an attentional guidance mechanism into a VR lab on students’ cognitive load and academic performance. We designed and developed two VR labs, one with and one without this attentional guidance stimulus (a 3D yellow arrow). A quasi-experimental design was adopted, and the data obtained were analysed using one-way ANOVA and linear regression. The experiment was conducted with 80 students majoring in digital media art at two universities. The results indicated that the students in the VR lab with the attentional guidance mechanism included exhibited lower cognitive load and higher academic performance than the control group. The regression analyses revealed that cognitive load negatively predicted learning outcomes; that is, academic performance improved as cognitive load decreased. In conclusion, as VR labs are increasingly used in education, supplementing them with attentional guidance stimuli can improve students’ academic performance by reducing their cognitive load.

Complete Laparoscopic Type C2 Radical Surgery for Cervical Stump Cancer: No-Look and No-Touch Techniques.

Due to previous surgical history and subsequent adhesions between pelvic organs, surgery for cervical stump cancer (CSC) is technically more challenging than surgery for cervical cancer with an intact uterus.1 We aimed to illustrate the related anatomy, surgical steps and techniques of complete laparoscopic type C2 radical surgery (CLRS) for early-stage CSC. CLRS for six patients with CSC was performed from January 2021 to January 2022. We demonstrated the detailed skills of parametrial management during CLRS for CSC in case 5 by means of a video. A 58-year-old woman diagnosed with International Federation of Gynecology and Obstetrics (FIGO) 2018 stage IIA1 CSC received CLRS through five operative ports (Fig.1). The magnetic resonance imaging (MRI) scans and gross appearance of the specimen are shown in Fig.2. The median age and body mass index (BMI) of the six patients were 53 years and 23.8, respectively. The median blood loss was 275mL; the median time of operation was 218min; the median length of hospitalization was 15 days; and the median time to recover urinary function was 12 days. One patient underwent postoperative radiation for pathologically proven adenocarcinoma with deep stromal invasion,2 while the other five did not. After a median follow-up of 24 months, no patients experienced complications, recurrence, or death (Table 1). This study details the skills of CLRS for CSC, especially space development and the 'no-look, no-touch' tumor-free principle. It is helpful for clinicians to perform safe and standardized surgery on patients with early-stage CSC. Fig.1 Trocar placement of complete laparoscopic type C2 radical surgery for early-stage CSC. CSC cervical stump cancer, S superior, I inferior, R right, L left, U umbilicus Fig.2 MRI scans and gross appearance of the specimen for case 5 with CSC at FIGO 2018 stage IIA1. The tumor lesion on the cervical stump is indicated by yellow arrows. a Axial T2-weighted image; b DKI image; c ADC map; d sagittal T2-weighted image; e sagittal T1-weighted image; f gross appearance of the surgical specimen. MRI magnetic resonance imaging, CSC cervical stump cancer, FIGO International Federation of Gynecology and Obstetrics, DKI diffusional kurtosis imaging, ADC apparent diffusion coefficient Table 1 Clinicopathological characteristics, operative details, and outcomes of patients with cervical stump cancer Patient no. Age at diagnosis (years) BMI Reasons for subtotal hysterectomy FIGO 2018 stage Histology Operation Operation time (mins) Blood loss (mL) Urinary catheter (days) Hospital stay (days) Complications Depth of invasion LVSI LNs dissected TNM stage Tumor size (mm) Postoperative radiotherapy Follow-up (months) Recurrence Death 1 50 25.9 Uterine myoma IIA1 ASC CLRS+PLND 221 360 10 12 No Middle one-third N 13 T2a1N0M0 16 No 30 No No 2 55 17.3 Uterine myoma IB1 AC CLRS+PLND 191 270 20 12 No Deep one-third N 24 T1b1N0M0 10 Yes 20 No No 3 50 24.8 Uterine myoma IB1 SC CLRS+PLND 295 310 13 15 No Superficial one-third N 21 T1b1N0M0 15 No 25 No No 4 63 30.1 Uterine myoma IB1 SC CLRS+PLND 213 180 6 16 No Superficial one-third N 25 T1b1N0M0 15 No 19 No No 5 58 20.2 Postpartum hemorrhage IIA1 SC CLRS+PLND 220 100 11 14 No Middle one-third N 21 T2a1N0M0 15 No 24 No No 6 46 22.7 Uterine myoma IB1 SC CLRS+PLND 215 120 14 17 No Superficial one-third N 26 T1b1N0M0 12 No 23 No No BMI body mass index, FIGO International Federation of Gynecology and Obstetrics, ASC cervical adenosquamous carcinoma, AC cervical adenocarcinoma, SC cervical squamous carcinoma, CLRS+PLND complete laparoscopic radical surgery and pelvic node dissections, LVSI lymphovascular space invasion, N negative, LNs lymph nodes, TNM tumor node metastasis.

Field Evaluation of Yellow Change and Red Clearance Intervals with Subsequent Permissive Left-Turn Flashing Yellow Arrow Indication

The flashing yellow arrow (FYA) indication has become commonly used for communicating permissive left-turn operations to road users. A conventional signal phasing communicated to left-turning drivers consists of a leading protected phase followed by a permissive phase using a FYA indication, often referred to as protected-permissive. To transition from the protected to the permissive phase, change (steady yellow arrow) and clearance (steady red arrow, all-red) intervals, or only a change interval, may be used. There is no specific guidance on the use of clearance intervals for left turns with protected-permissive phase and FYA indication. In this study, field data were collected from different geographical regions in the United States to evaluate change and clearance intervals with the objective of developing guidance. Video data were recorded at 37 intersections during peak hours, for approximately 142 h, across eight states. Overall, 4,001 observations of vehicles turning left during the change or clearance interval were analyzed. Field observations were evaluated at the approach level to assess left-turn violation rate and violations per cycle as a function of change and clearance interval configuration. At the individual vehicle level, logistic regression was implemented to evaluate the effect of change interval and clearance interval duration, delayed onset of FYA, and regional variation. The results of the analysis at the approach and individual vehicle level were consistent and indicate that: (i) a clearance interval should be included, (ii) delaying the onset of FYA indication with an extension beyond the all-red clearance interval would reduce left-turn signal violations, and (iii) duration of change intervals has a marginal impact on left-turn signal violations.

Field Assessment of Variable Left-Turn Mode by Time-of-Day for Intersections Being Upgraded With Flashing Yellow Arrow Signal Heads and Offset Left-Turn Lanes

The present study conducted a field assessment of variable left-turn (VLT) mode by time-of-day (TOD) plan for signalized intersections being upgraded with offset left-turn lanes and four-section vertical flashing yellow arrow (FYA) signal heads in Alabama. The VLT-TOD plan involved changing left-turn phasing from protected-permissive left-turn to permissive by TOD, based on left-turn and corresponding opposing traffic volume criteria at selected intersections. Consequently, the field assessment involved comparing surrogate safety and traffic operational measures for permissive left-turn and through traffic movements before and after the VLT-TOD implementation. Video and signal event data were collected in before and after conditions of the VLT-TOD implementation for the field assessment. The before–after comparison of safety and operational measures revealed that the VLT-TOD plan coupled with the FYA signal heads facilitated improved operational efficiency for the through traffic without compromising the safety and traffic operations of left-turning drivers at the study sites during the TOD hours. The results showed that surrogate measures, such as critical gap, postencroachment time, and follow-up time for permissive left-turns, remained unchanged before and after implementing the VLT-TOD plan, whereas a significant increase in the percent of green arrivals for through traffic was observed. The results are promising as they indicate that at signalized intersections with significant traffic volume fluctuation, the VLT by TOD plan utilizing the four-section FYA signal heads has the potential to significantly enhance overall traffic operations, particularly in situations in which drivers do not encounter sight-distance issues during the permissive left-turn phases.

Quasi-in-Situ Analysis of Electropolished Additively Manufactured Stainless Steel Surfaces

Progress in additive manufacturing is leading to the emergence of new areas of application. Laser Powder Bed Fusion (L-PBF) is increasingly used for the development of metallic medical implants, but for high-risk implants like vascular support structures (stents), surface quality is critical to ensure successful implantation without harming the surrounding tissue and ensure the patients’ health. Therefore, enhancing the surface quality is crucial. Electropolishing is a method for removing surface roughness by smoothing out micro-peaks and valleys. However, L-PBF structures have a high surface roughness due to metal particles adhering on the surface. To achieve a smooth surface for additively manufactured implants like stents using electropolishing, the removal of these particles needs to be studied in more detail.The objective of this study is to examine the electropolishing mechanism of 316L stainless steel samples additively manufactured through Laser Powder Bed Fusion (L-PBF). The main objective is to investigate the removal properties and surface characteristics during electropolishing. To achieve this, various surfaces were characterized for morphology and roughness during Hull cell experiments. Markings are utilized on the Hull cell sample surfaces to identify points of interest during quasi-in-situ measurements. The surfaces are then analyzed after multiple time steps, applying different currents to investigate particle dissolution. The surface characteristics are analyzed through scanning electron microscopy, and surface roughness is analyzed using laser scanning microscopy.The results show that the electropolishing process preferentially removes the adhering particles present on the surface of the samples. Increasing the current density results in faster particle dissolution and a smoother surface (see Figure 1a and b). The mechanism of material removal of various surface features, as shown in Figure 1 (red circle, yellow arrow and red square), was assessed based on the experimental results of the surface structures seen on the SEM images. It was found that different surface features were removed during the experiment at different polishing times and current densities. The amount of charge flowed was found to correlate with surface morphology.Based on the obtained results, various surface features (such as large adherent particles, agglomerates of smaller particles, and valleys) and their changes with increasing test duration and current density were observed by quasi-in situ analyses. A reduction in the diameter of round particles adhering to the surface was observed at both low and higher current densities (see Figure 1a red circle a). Increasing the polishing time resulted in leveling of both large particles and valleys (see Figure 1b red square). Also, dissolution of agglomerates of smaller particles occurred at different polishing times as a function of current density and polishing time (see Figure 1a yellow arrow) are observed.Smoothed surface structures can be observed in regions with equivalent surface charge density (see Figure 2). As a result, comparable surface morphologies may appear at the same area charge density, irrespective of a specific current density. So, it may be adequate to only consider the amount of charge flowed to describe the electropolishing of additive materials.In conclusion, comprehending the dissolution characteristics of particles on L-PBF surfaces is essential for attaining satisfactory surface finish in electropolishing. The results of this study offer valuable perspectives into the electropolishing mechanism of additively manufactured 316L stainless steel and can guide future investigations on surface finishing and polishing of additive manufactured implants like stents. Figure 1

Synchrotron-based X-ray phase contrast imaging of transmural cardiac tissue in patients treated for advanced heart failure

Abstract Background Cardiac imaging is essential for identifying structural changes in advanced heart failure (HF) and understanding underlying pathophysiology. Synchrotron radiation-based X-ray phase contrast imaging (X-PCI) is a non-destructive imaging modality that can provide high resolution three-dimensional (3D) visualisation of cardiac tissue on the microstructural level. Thus far, such analyses including the quantification of myocyte aggregates ranging from the epicardium to the endocardium, have been confined to animal models and human fetal tissue. We aimed to explore the feasibility of using X-PCI to quantify and compare structural organisation and orientation of myocyte aggregates in the myocardium across different advanced HF aetiologies. Methods and design Four adult patients were included - two receiving a left ventricular assist device (LVAD), and two undergoing heart transplantation (HTx). Aetiology of advanced HF in both the LVAD and HTx group was ischaemic heart disease and dilated cardiomyopathy (DCM), respectively. Transmural tissue samples were obtained by left ventricular apical coring (LVAD) and from the explanted hearts (HTx). The tissue specimens were imaged by X-PCI at the TOMCAT beamline using an effective pixel size of 5.8 µm. Orientation of aggregates of cardiomyocytes was assessed using a structure tensor-based method and morphological parameters were derived - the helical angle (HA), or the angle between the circumferential left ventricular plane and myocyte aggregates, and fractional anisotropy (FA), the degree of anisotropy or disorganisation of the local myocardium. Results The general patient characteristics are shown in Table 1. X-PCI enabled 3D visualisation of transmural myocardial tissue samples showing differences in organisation of myocardial structure in different HF aetiologies (Figure 1). The epicardial adipose layer was thicker in DCM, paired with a thinner epicardial myocyte layer (yellow arrows). Furthermore, the epi-to-endocardial HA transition was clearly visualized in ICM (double arrows), whereas there was clear disruption of the HA gradient in DCM samples – a finding further quantified via FA (green arrows). Conclusion X-PCI allows non-destructive advanced imaging of ex-vivo tissue. By harnessing the power of digital 3D imaging on a cellular level, it provides a novel insight to differential information on tissue organisation in different aetiologies of advanced heart failure.Table 1Figure 1

Abstract 111: Woven Endo Bridge‐Coil Embolization of a Middle Cerebral Artery Bifurcation Aneurysm with Secondary Lobule

Introduction 18‐36% of all intracranial aneurysms are middle cerebral artery(MCA) bifurcation aneurysms. While some are much higher risk than others, they have an overall low estimated annual rupture rate of 0.36%.(1) MCA bifurcation aneurysms have been historically challenging to treat endovascularly given they often have complex morphology and wide necks. The Woven EndoBridge (WEB) is an ellipsoid embolization device designed to provide intrasaccular flow disruption along the aneurysm neck, which has been proven to be an effective method in treating a wide spectrum of wide‐necked bifurcation aneurysms. Thromboembolism and recanalization are the main concerns in treatment with the WEB device, like any aneurysm treatment approach .(2),(3) Occasionally, irregularities and secondary lobules at the base of the primary aneurysm can have persistent filling despite treatment. Methods We present a case of a right MCA bifurcation aneurysm treated by a WEB device and coil embolization. Results 48‐year‐old female with a medical history significant only for active smoking who presented with sudden onset of the worst headache of her life followed by brief loss of consciousness. No neurological evaluation was sought initially, until 2 weeks later as she continued to experience a moderate‐intensity headache associated with nausea and vomiting with frequent falls. On exam, she was alert and oriented, moving all extremities with full strength. CT head revealed an evolving acute to subacute right MCA infarction with adjacent small volume subarachnoid hemorrhage. CTA head revealed a right MCA bifurcation aneurysm measuring 6 x 6 x 7 mm with irregularity of the wall. Multifocal severe stenosis was noted in the right distal right M1 and right M2 divisions. She underwent a diagnostic subtraction angiography which confirmed an irregular right MCA bifurcation aneurysm measuring 4.3 x 4.5 x 5.7 mm (Figure 1 ‐A,B). While it was believed that the subarachnoid hemorrhage was more likely related to the recent infarct, a decision was made to treat the aneurysm given its relatively large size and irregular shape. Embolization was performed with a WEB SL 6 x 4 mm device (Figure 1: C,D ‐blue arrow). Post‐deployment angiograph showed occlusion of the aneurysm dome but persistent filling of the secondary lobule near the base of the aneurysm. Given this residual lobule filling, a decision was made to continue additional embolization with a hyper soft 3D 2 mm X 2 cm coil(Figure 1: C,D ‐ yellow arrow). Final angiography revealed complete occlusion of the aneurysm. Vasospasm of the distal M2 divisions and multiple M3 branches in the right MCA vascular territory was also noted. Therefore, she was treated with 20 mg of intra‐arterial Verapamil with improvement. She was started on Aspirin 325 mg daily. Daily transcranial dopplers were negative for vasospasm. She remained neurologically stable and was discharged home 5 days after admission ambulating independently. Conclusion With modern advances in endovascular devices, many MCA bifurcation aneurysms can be treated minimally invasively. However, there are some limitations to the WEB since every aneurysm is different and there are a finite number of sizes and shapes available for WEB. This case illustrates that adjunctive coil embolization can successfully occlude a residual secondary base lobule after WEB embolization.

Issue Information

Our study investigated the three‐dimensional morphology of the human spleen during the early fetal period. The 3D models of the spleen (yellow arrows) and the surrounding organs were created using fetal MRI (A, B). Spleen morphology was classified into six types based on the number and features of splenic surfaces, indicating that the number of surfaces increased as crown‐rump length (CRL) enlarged (C). Further details can be seen in the article by Utsunomiya et al. in this issue. image

Keratic precipitates morphology in vitreoretinal lymphoma evaluated with in-vivo confocal microscopy

A 51-year-old female patient presented to our department with a one-year history of bilateral blurred vision with floaters. Ocular examination showed bilateral vitritis with a moderate haze which was more accentuated and prominent at the periphery in the right eye (OD) (figure 1 A, asterisks). Spectral-domain optical coherence tomography (SD-OCT) showed numerous pigment epithelial detachment (figure B, white arrows), with a lumpy-bumpy choroid. The diagnosis of vitreoretinal lymphoma (VRL) was suspected and confirmed histologically by the presence of atypical lymphocytes in the vitreous samples and an elevated Interleukin (IL)-10 to IL-6 ratio. In addition to those posterior segment manifestations, slit-lamp examination of the OD showed central stellate granulomatous keratic precipitates (KPs) (figure C). On in-vivo confocal microscopy (IVCM), those infiltrating KPs appeared as a hyperreflective deposit at the level of the corneal endothelium with a dendritic shape, and were interconnected by multiple thin and fibrillar pseudopodia in a comet-like appearance (figure D, yellow arrows), which is a highly suggestive pattern of KPs of VRL associated anterior uveitis when the latter is unusually granulomatous.

Evaluating Right-Turn Flashing Yellow Arrow for Vehicle–Pedestrian Interactions Using a Non-Probabilistic Regression Approach

Using video, interactions between right-turning vehicles and pedestrians were documented for sites with a permissive circular green or a flashing yellow arrow (FYA) permissive right-turn indication. Timestamps associated with key vehicle and pedestrian positions were documented and used to calculate three metrics: time for driver to complete right turn (with and without a pedestrian presence) and the time for the pedestrian to arrive at the theoretical conflict point of vehicle–pedestrian interactions. Using timestamp data, multiple non-probabilistic linear regression models were created to describe the relationship between the position of the pedestrian within the crosswalk and the time for a right-turning vehicle maneuver to be completed. Model results implicitly describe the attitude of drivers toward pedestrian presence on the crosswalk. Larger right-turning maneuver completion times are arguably an indicator of greater respect toward pedestrian presence. Given the nature of the model’s output, a pedestrian respect indicator (PRI) based on the value of model parameters is introduced as a potential indicator of the safety of vehicle–pedestrian interactions. PRI values can be computed for individual sites thus allowing its use as a safety indicator. The higher the PRI, the more “respect” toward pedestrians. Proof-of-concept modeling results based on available timestamp data suggest that interactions controlled by a right-turn FYA indication have a higher PRI than interactions controlled by a circular green. An argument is made that PRI values can be potentially used to proactively evaluate the effectiveness of traffic control devices and other safety countermeasures without the need for crash data.

CARD10: Transapical Left Ventricular Assist Device Implantation Using a Novel Accessory in Swine

Background: Conventional left ventricular assist devices (LVADs) require an anastomosis of the outflow graft to the ascending aorta. We developed and tested a LVAD accessory, which combines pump in- and transaortic outflow in a dual lumen adapter, thus, allowing LVAD implantation solely via the left ventricular apex. Methods: The LVAD accessory (Fig. A) consisted of a 3D printed titanium inflow and a 12 mm outflow stent graft. The accessory in combination with a centrifugal LVAD (HeartMate 3, HM3, Abbott, USA) was implanted in 10 adult female Landrace pigs (104 ± 13 kg). A balloon catheter (14 mm Atlas Gold PTA Dilatation Catheter, BD, USA) was introduced via the left femoral artery and placed in the left ventricle. After lower partial sternotomy, pericardiotomy and fixation ring attachment, apical coring was performed in a standard fashion on the beating heart using cardiopulmonary bypass. The balloon was exteriorized, inflated in the outflow graft and both, the accessory with the attached outflow graft, were pulled into the left ventricle and the aorta. The accessory was attached to the fixation ring. The LVAD was connected and deaired, and the balloon catheter was removed. Results: After successful LVAD implantation in all animals, echocardiography revealed no signs of aortic or mitral regurgitation. In eight animals ramp testing was performed. The HM3 flow estimate increased from 3.7 ± 1.2 L/min at 4’500 rpm to 5.4 ± 1.2 L/min at 7’200 rpm (Fig. B). Post-mortem examination (Fig. C) revealed correct placement of the LVAD accessory with the inflow in the left ventricle (blue arrow) and the outflow graft across the aortic valve (yellow arrow). There were neither signs of damage of the aortic (*) or mitral valve (+) nor signs of thrombosis. Conclusion: The novel accessory in combination with a centrifugal LVAD allowed safe and less-invasive LVAD implantation. Ramp testing revealed effective left ventricular support in the acute swine model. Further testing in a chronic heart failure model will be performed to validate these results.

Transuterine Ultrasound-Guided Fetal Embolization of Vein of Galen Malformation, Eliminating Postnatal Pathophysiology.

Transuterine Ultrasound-Guided Fetal Embolization of Vein of Galen Malformation, Eliminating Postnatal Pathophysiology.

PO-04-015 BIVENTRICULAR ARRHYTHMOGENIC CARDIOMYOPATHY ASSOCIATED WITH A NOVEL HETEROZYGOUS PLAKOPHILIN-2 EARLY TRUNCATING VARIANT

N/A N/A N/A A 31-year-old male patient suffered from palpitations, which occurred particularly during and shortly after physical activity. The patient was very athletic and took part in marathons. His family history was unremarkable. The electrocardiogram showed T wave inversions in V1-V3 (Figure 1A). During bicycle ergometry monomorphic premature ventricular complexes (PVC) and non-sustained ventricular tachycardia episodes (left-bundle branch block morphology, inferior axis) evolved (Figure 1B, black arrow). Of note, under maximal physical stress a second PVC with a right-bundle branch block morphology occurred (Figure 1B, red arrow) suggesting left ventricular (LV) involvement. Echocardiographic evaluation showed a dilated right ventricle (RV) with reduced systolic function, a subtricuspid aneurysm and multiple sacculations of the RV free wall (Figure 1C-D, white markers). Cardiac magnetic resonance imaging (MRI) confirmed the right ventricular findings (Figure 1E, red arrows). In addition, late gadolinium enhancement and fatty deposits were visible in the LV lateral wall (Figure 1F-G, yellow arrows and blue asterix). Genetic testing was performed using a panel covering 173 genes (Agilent, SureSelectQXTTarget Enrichment) and next generation sequencing (NGS) (Illumina MiSeq). It revealed a novel heterozygous nonsense variant in the plakophilin-2 (PKP2) gene (808C>T p. (Gln270Ter) in exon 3) that causes an early truncation, which was confirmed by Sanger sequencing. It was classified as pathogenic (class V). Cascade screening of the asymptomatic patient’s mother (64-y-old), father (70-y-old) and sister (33-y-old) showed that the patient's father and sister harbored the same PKP-2 variant. Both did not report a history of participating in competitive sports, and thorough cardiac evaluation of these two genotype positive family members showed normal findings. Previous studies have indicated that early truncation of the PKP2 C-terminus likely causes arrhythmogenic right ventricular cardiomyopathy (ARVC) irrespective of transcript position. Although desmosomal and non-desmosomal variants create certain genetic potential for the development of ARVC, exercise has an important role in determining the development, severity, and pattern of phenotypic expression. The fact that the only index patient, as a marathon runner, developed ARVC, suggests that the novel PKP2 variant poses a genetic risk, but is not sufficient for inducing an ARVC phenotype by itself.

頸髄損傷に合併した経鼻胃管症候群の1例(A case of nasogastric tube syndrome with cervical spinal injury)

経鼻胃管症候群とは，経鼻胃管留置後に咽頭痛，両側声帯の外転麻痺，喉頭浮腫を発症する症候群である。両側声帯麻痺を認めれば気道緊急を要し，しばしば致命的となる。症例は46歳の男性。墜落外傷により当院搬送となった。精査の結果，外傷性くも膜下出血，第6・7頸椎・第6–10胸椎骨折，第6・7頸髄・第6–8胸髄損傷と診断し，入院加療を開始した。第2病日麻痺性イレウスを発症し，経鼻胃管を留置し，減圧加療を開始した。第11病日吸気性喘鳴を聴取し，酸素8L/分投与下でSpO2（経皮的酸素分圧）88%まで低下を認めた。喉頭ファイバースコピー検査で両側声帯麻痺を認め，気道緊急として経口気管挿管を施行し，人工呼吸管理を開始した。第14病日気管切開術を施行した。第39病日声帯麻痺の治癒を確認した。第45病日リハビリテーション目的に転院した。 Nasogastric tube syndrome presents as throat pain, bilateral abductor paralysis of the vocal cords and pharyngeal edema after nasogastric tube placement. This syndrome often requires emergency airway management due to bilateral abductor paralysis and thus can be fatal. A 46–year–old man was transported to the emergency room due to trauma from a fall. We diagnosed traumatic subarachnoid hemorrhage, cervical and thoracic spine fractures, and cervical and thoracic spinal cord injury, and admitted him. On hospital day 2, a nasogastric tube was inserted due to paralytic ileus. On day 11, wheezing was heard on exhalation, and his SpO2 decreased to 88% on oxygen at 8L/min. Laryngeal fiberscopy revealed bilateral vocal cord paralysis, so he was intubated orally. A tracheotomy was performed on day 14. The vocal cord paralysis had healed by day 39, and on day 45, he was transferred to another hospital for rehabilitation. 経鼻胃管症候群とは，経鼻胃管留置後に咽頭痛，両側声帯の外転麻痺，喉頭浮腫を発症する症候群である。両側声帯麻痺を認めれば緊急気道確保を要し，しばしば致命的となる。今回，頸髄損傷を背景として経鼻胃管留置中に両側声帯麻痺を発症した1例を経験したので報告する。 当論文は当院倫理委員会の承諾を受け，個人情報保護法に基づいて匿名化を行っている。また，患者およびその家族から論文の出版に関する同意を得ている。 患 者：49歳の男性。身長180cm，体重91.6kg，BMI 28.3 既往歴：統合失調症 内服薬：アリピプラゾール，フルニトラゼパム，ゾルピデム酒石塩酸，クエチアピンフマル酸塩，アムロジピンベシル酸塩 現病歴：自宅3階からの飛び降りによる転落外傷で受傷した。目撃者が救急要請し，当院救急搬送となった。 来院時現症：気道は開通，呼吸音 清，呼吸様式 正常，呼吸数16/分，SpO2 97%（酸素10L/分 投与下），血圧85/45mmHg，脈拍72/分，Glasgow coma scale E3V5M6，瞳孔径2mm/2mm，対光反射は両側迅速，体温36.2度（腋窩温）であった。 身体所見：後頭部に約20cmの裂創を認めるが活動性出血は認めなかった。右膝・両踵に擦過傷を認めた。徒手筋力テストは両上下肢いずれもMMT 3以上であるが，意思疎通がとれず，詳細な評価は困難であった。持続勃起や肛門括約筋の弛緩は認めなかった。 血液検査：WBC 17,300/µL（Neut 89.4%），Hb 16.4g/dL，Plt 34.9×104/mm3，PT–INR 1.17，Fibrinogen 180mg/dL，APTT 22.2秒，D–dimer 41.21µg/mL 動脈血液ガス分析（酸素マスク10L/分投与下）：pH 7.359，PaCO2 38.0mmHg，PaO2 148.1mmHg，HCO3− 20.9mmol/L，B.E. −4.0mmol/L，lactate 29.2mg/dL 全身CT画像検査：外傷性くも膜下出血，第6・7頸椎棘突起骨折，左第4・5肋骨骨折，第6–8・10胸椎椎体骨折を認めた。 来院時ショックの状態であり，神経原性ショックの可能性を念頭に置いて診療したが，輸液負荷のみで血圧は安定し，入院加療を開始した。血液検査でのWBCおよびD–dimerの上昇は外傷に起因するものと判断した。第2病日，腸蠕動音減弱および腹部レントゲン検査で小腸の拡張を認め，麻痺性イレウスと診断し，減圧目的に20Frの経鼻胃管を留置した。第3病日下肢の筋力低下の訴えがあり，頭部・頸椎・胸椎MRI撮像したところ，T2強調像で第6椎体前面および第6–7頸髄内，第6–8胸髄内の高信号を認め，第6–7頸髄損傷，第6–8胸髄損傷と診断した（Fig. 1）。頸椎カラー装着継続で保存加療の方針とした。リハビリテーション目的の転院調整を開始しようとしたが，第11病日突然の吸気性喘鳴を認め，ボスミン筋肉注射を行うも改善を認めなかった。喉頭ファイバースコピー検査で両側声帯麻痺と診断した（Fig. 2A）。次第にSpO2は低下し，酸素8L/分 投与下にSpO2 88%前後まで酸素化低下を認めた。その時点での動脈血液ガス分析では，pH 7.501，PaCO2 48.8mmHg，PaO2 67.9mmHg，HCO3− 37.3mmol/L，B.E. 12.5mmol/L，lactate 11.8mg/dLと低酸素血症，高二酸化炭素血症を呈していた。経口気管挿管による気道確保を行い，人工呼吸管理を開始した。その後は原因検索を行ったが器質的疾患はいずれも否定的で，経鼻胃管症候群と診断した。麻痺性イレウスは遷延しており，経鼻胃管の抜去は困難であったため，第13病日経鼻胃管を18Frに入れ替えた。長期の気管挿管となることが予想され，第14病日気管切開術を施行した。腸蠕動音正常，腹部レントゲン検査で小腸の拡張の改善を認め，麻痺性イレウスの治癒と判断し，第16病日栄養投与目的に経鼻胃管を10Frに入れ替えた。第39病日喉頭ファイバースコピー検査で声帯麻痺の治癒を確認した（Fig. 2B）。精神状態悪化による昏迷状態となっており，気管切開チューブはスピーチカニューレへの入れ替えにとどめた。第45病日頸椎カラーは装着を継続しリハビリテーション目的に転院した（injury severity score: 17，probability of survival: 0.97972であった）。 Magnetic resonance imaging of the cervical and thoracic vertebrae. MRI（T2）revealed spinal cord injury at the sixth and seventh cervical vertebrae and from the sixth to eighth thoracic vertebrae (red arrow), and 5–mm retropharyngeal hematoma (yellow arrow). Laryngeal fiberscopy. A: Laryngeal fiberscopy showed abnormal abducton of the vocal cords. (during the phase of expiration (left) / inspiration (right)) B: Laryngeal fiberscopy showed recovery of the vocal cords from abductor disorder. (during the phase of expiration (left) / inspiration (right)) Cervical computed tomography (CT). Computed tomography revealed a 6–mm retropharyngeal hematoma (red arrow). 経鼻胃管による咽頭への影響は1939年Wangensteen 1により初めて報告され，その後しばしば症例報告が散見される程度であった。1981年Sofferman 2は，経鼻胃管留置中に咽頭痛，片側あるいは両側の声帯の外転機能不全を来す症候群を経鼻胃管症候群と定義した。診断は，喉頭ファイバースコピー検査で声帯麻痺と診断し，かつ原因となりうる疾患を除外したうえで，臨床的に診断することが多い。発症のタイミングは経鼻胃管を留置して12時間後から抜去2週間後まで多様である 3。 病態は完全には解明されておらず，機序として，①咳嗽や嚥下の際に固定された経鼻胃管と咽頭が垂直方向へ摩擦が起きること，②仰臥位で輪状後部が頸椎側から経鼻胃管により圧迫される，③輪状咽頭筋の収縮が経鼻胃管を脆弱で薄い輪状軟骨後板へ持続的に引き上げる，といったことが推測されている 2。その結果，経鼻胃管による輪状後部への持続的圧迫から結果的に潰瘍形成や感染，虚血が生じ，後輪状披裂筋の機能不全が生じると考えられている 2, 4。糖尿病や低免疫状態，低栄養，加齢に伴う粘膜弾性の低下，パーキンソン症候群，脳血管障害に伴う生理的な嚥下運動の減少による除圧頻度の減少，輪状軟骨レベルでの骨棘突出がリスク因子と言われている 2, 5, 6。経鼻胃管の太さがリスク因子とする報告はない。桜井ら 7による10Frの経鼻胃管を留置していた4例の報告があり，決して細いチューブがリスクを軽減するわけではないと考えられる。またチューブの径が太い方が輪状後部への影響を与える可能性は高く，リスクとなりうると考えるが，今後検討すべき事項である。Friedmanらは，経鼻胃管が声帯部を正中で走行するのは約6%と少ないものの，動物モデルで側方を走行するより正中を走行する方が炎症を生じやすい可能性があると報告している 8。 本症例において，初療時のCT画像や第3病日のMRI画像では声帯自体や輪状軟骨後部を含め声門周囲の直接的な外傷性変化は指摘できなかった。咽頭後間隙の血腫は第1病日のCTで6mm，第3病日のMRIで5mmであった（Fig. 1, 3）。リスク因子は入院後に発症した麻痺性イレウスの影響による低栄養のみであった。経鼻胃管はCT画像で確認する限り，声門部では側方を通過していた。喉頭ファイバースコピー検査の際も側方を通過しているのを確認できた。入院後は頸髄損傷のため，仰臥位での安静時間がほとんどであった。しかし，頸髄損傷で経鼻胃管の留置が必要であった患者はこれまで多く経験しているが，当院で経鼻胃管症候群と診断したのは初めてであり，頸髄損傷などで輪状軟骨レベルでの損傷がある外傷症例での経鼻胃管症候群の報告は，我々が渉猟する限り見られなかった。以上から，本症例では低栄養状態や長期臥床の影響だけでなく，リスク因子として知られている輪状軟骨レベルの骨棘突出と同様の機序で，頸部外傷による咽頭後間隙の血腫・炎症性変化が経鼻胃管による輪状後部への刺激を増強し，炎症や虚血を起こしたのではないかと考えられた。頸髄損傷に偶発的に合併した可能性は否定できないが，椎体前面の外傷性変化が一因となり，経鼻胃管症候群を発症しうることが示唆された。椎体前面に血腫を形成する頸髄損傷の症例には重症度の差がある。軽症例では，通常経口摂取が可能で経鼻胃管が留置される可能性は高くない。一方，重症例では，腹式呼吸や喀痰喀出困難を原因とした呼吸不全に対する気管挿管のタイミングで経鼻胃管が留置されることが多い。その後十分な声帯の評価が行われずに気道確保や気管切開が行われていることが多く，経過中に経鼻胃管症候群を発症していても認知されていない可能性がある。本症例は腹式呼吸を呈するような重症例ではなかったものの，イレウスを発症したことで経鼻胃管が留置され，頸椎前面の外傷性炎症と相まって，経鼻胃管症候群の発症に至った。それに加え，咳嗽減弱や喀痰喀出困難をそれまで認めていなかったという経過から，本症に気づくことができたのではないかと考えた。 治療は経鼻胃管の抜去が必須とされている 9。その他，抗菌薬やPPI，副腎皮質ステロイドなどが投与された報告はあるが，確立した治療法はない。声帯外転障害が改善せず気管カニューレが抜去できないこともある 3。本症例では，治療上経鼻胃管を抜去することは困難であり，まずは経鼻胃管を減圧の治療の障害にならない範囲で細いものに入れ替えたのちに，経鼻胃管を留置している限り短期間での治癒は見込めないと判断し，気管切開術を行った。発症から29日後に声帯麻痺の治癒を確認できた。検索する限り今まで経鼻胃管を抜去せずに経鼻胃管症候群が治癒したという報告は見られなかった。治癒までの期間は長くなるかもしれないが，本症例のように治療上必要であれば経鼻胃管を抜去せずとも治癒する可能性があることが示唆された。 本症例は外傷症例の亜急性期に発生した吸気性喘鳴を契機に，各疾患を除外してから経鼻胃管症候群と診断できた。経鼻胃管症候群は比較的近年に定義された症候群であり，とくに2010年以降の症例報告が増加している 7, 9。これに関しては，経鼻胃管の留置数が著明に増加しているわけではないと考えられることから，発症する頻度が増加したわけではなく，この疾患の概念が認識され始めたことに影響しているものと推測された。対応が遅れると致命的となりうるだけでなく，本疾患を鑑別に入れておかないと経鼻胃管を抜去するなどの対応が遅れ，治癒までの期間が延長しうる。とくに救命・集中治療部門において経鼻胃管は留置されていることの多いデバイスであり，経鼻胃管を留置する際は本合併症に留意して管理を行う必要がある。 椎体前面の外傷性変化が一因になったと考えられた経鼻胃管症候群の1例を経験した。経鼻胃管はよく留置されるデバイスであり，両側声帯麻痺を発症した場合，緊急気道確保を行うとともに，経鼻胃管症候群を鑑別に挙げて治療を行う必要がある。 本論文の要旨は第122回近畿救急医学研究会（2021年，大阪）で発表した。 本稿のすべての著者に規定された利益相反はない。

MitraClip single-leaflet detachment and consequent migration in atrial functional mitral regurgitation.

An 84-year-old woman with symptomatic severe functional mitral regurgitation (MR) due to long standing atrial fibrillation underwent percutaneous edge-to-edge repair using the MitraClip system (Abbott Vascular, Santa Clara, CA, USA) (see Supplementary data online, Video S1). Following deployment of an XTR clip in the A2-P2 segment, a second MitraClip XT device was deployed laterally to prevent recurrence of MR caused by stretching of left atrium and mitral leaflets. However, single leaflet detachment of the anterior leaflet occurred immediately (Panel A, Supplementary data online, Video S2). Since only mild MR was observed after the procedure, additional clipping was not performed, and her symptoms were relieved. However, at 2 weeks after discharge, she presented with right inguinal pain and aggravated dyspnea. The lateral clip was not observed on chest x-ray (Panels B and C). Computed tomography revealed the migrated MitraClip at the right common iliac artery bifurcation (yellow arrows in Panel D). Transesophageal echocardiogram showed recurrence of severe MR with newly developed small chordae rupture (Panel E, Supplementary data online, Video S3). The embolized MitraClip was successfully retrieved using 10- and 15-mm Amplatz GooseNeck® snares (Ev3, Plymouth, MN, USA) through a 16-French Check-Flo® Introducer sheath (Cook Medical, Bloomington, IN, USA) (Panels F, G, and H, Supplementary data online, Video S4), and another NTW clip was deployed. Post-procedure transesophageal echocardiogram confirmed residual mild to moderate MR (Panel I, Supplementary data online, Video S5). Images from this case show the complications of MitraClip single leaflet detachment and distal migration, and how this problem was solved.

Misplacement in myocardial contrast echo during alcohol septal ablation in hypertrophic obstructive cardiomyopathy indicates intraseptal collateralization.

A 42-year-old patient with HOCM was submitted for percutaneous transluminal septal myocardial ablation (PTSMA). Coronary angiography (Panel A) identified the first septal branch (SB) (yellow arrow) as estimated target vessel and a second SB (white arrow). Compared with intraprocedural baseline transthoracic echocardiography (TTE) (Panel B), myocardial contrast echocardiography (MCE) with injection of 1.5 mL cold gelafundin 4% through an inflated over the wire balloon catheter (OTW-BC) in the first SB (Panel C) identified a correct septal depot (orange arrow), but also opacification at the left ventricle apex (dotted orange arrow). Contrast dye injection through the OTW-BC (dotted yellow arrow) showed collateralization from the first (yellow arrow) into the second SB (yellow arrow) and drainage into the left anterior descending (LAD) (red arrow) as reason for the misplacement (Panel D). We placed a second OTW-BC in the collateralized second SB (dotted white arrow; Panel E). Contrast injection through both inflated OTW-BC showed only distal first (yellow arrow) and second SB (white arrow) without further collaterals and without drainage into the—in the meantime wired—LAD (red arrow). MCE (Panel E) showed only opacification of the targeted septal area (orange arrow) as TTE (Panel F) does after injection 1.5 cc of alcohol through each balloon. After deflation and retraction of the BCs, 10 min after alcohol injection, haemodynamic measurements ensured elimination of resting and provocable gradients. Final coronary angiography (Panel G) showed occluded SBs (arrows) and unchanged LAD.

Developing a Tracking-Based Dynamic Flash Yellow Arrow Strategy for Permissive Left-Turn Vehicles to Improve Pedestrian Safety at Intersections

Developing a Tracking-Based Dynamic Flash Yellow Arrow Strategy for Permissive Left-Turn Vehicles to Improve Pedestrian Safety at Intersections

A stalk with no polyp-A muco-submucosal elongated polyp in the duodenum.

A 62-year-old Caucasian man was referred for upper GI endoscopy with a 6-month history of intermittent abdominal pain, nausea and bloating. Endoscopy revealed a 5-cm elongated lesion arising in D2. A pedunculated polyp (0-Ip) was suspected; however, deeper intubation revealed no polyp at the end of the stalk (Figure 1). Narrow band imaging did not reveal any adenomatous or suspicious features (Figure 2). The base of the polyp was injected with EMR solution (gelofusin, methylene blue and adrenaline 1:100,000), resected by snare cautery (Figure 3) and the defect was closed with two endoclips. Histopathology confirmed a 42 mm × 15 mm cylindrical lesion of hyperplastic duodenal mucosa with submucosal expansion by fibroconnective tissue. Histological analysis demonstrated features of a prominent submucosal vascular component with dilated lymphovascular structures, the absence of inflammatory infiltrate and the absence of significant architectural disturbance (Figure 4). These findings were consistent with a diagnosis of a muco-submucosal elongated polyp.1, 2 Muco-submucosal elongated polyp of the GIT under white light. Muco-submucosal elongated polyp of the GIT under narrow band imaging (NBI). Muco-submucosal elongated polyp of the GIT following resection. Histology section (2X) through the polyp shows architecturally normal small intestinal mucosa (yellow arrow) overlying a core of submucosa containing abundant adipose tissue (blue arrow) with submucosal vessels (green arrows). No significant inflammation is seen. Enteric muco-submucosal elongated polyps are rare, benign gastrointestinal polyps with an elongated, cylindrical ‘worm-like’ endoscopic appearance that is a hallmark of the disease.2, 3 Initially identified in the colon,1 few cases have been reported in the small bowel.3 It is hypothesised that peristaltic movements serve as mechanical traction for redundant mucosa, creating a nidus for polyp growth in these mucosal areas. They can mimic a number of other enteric lesions, in particular prolapsing mucosal folds (associated with diverticular disease) and filiform polyps (associated with inflammatory bowel disease). Immunohistochemistry demonstrates positivity for endothelial vascular markers (CD31) and endothelial lymphatic vessels (D2-40/podoplanin). Endoscopic ultrasound (EUS) can demonstrate the mucosal and submucosal layers of the polyp, with characteristic microcystic components aiding the diagnosis. Symptomatic patients can be treated by endoscopic resection, although treatment may be considered in asymptomatic cases given case reports suggesting an associated risk of intussusception,4 diverticulitis5 and non-polypoid neoplasia.6, 7 Surveillance gastroscopy 3 and 12 months post resection did not reveal any residual polyps. The authors wish to acknowledge the patients who attend, and staff who work in the Endoscopy Unit and the contribution they make to clinical research. There was no funding source for this research. The authors have no conflicts of interest to declare. Data sharing not applicable to this article as no datasets were generated or analysed during the current study.

Evaluation of Dynamic Flashing Yellow Arrow Decision Support System in the Field Using Before and After Real-Time Data

A permissive left turn is one of the most dangerous movements a driver can make because the driver travels across opposing traffic lanes. In recent years, flashing yellow arrow (FYA) signals have been proven to help drivers make safer left turns. The four-section signal display with FYA permissive left-turn indication creates an opportunity to enhance the left-turn phase with a variable mode that can change on demand. A challenge to using this system is knowing the best times of day to apply the FYA indication. The authors developed an exclusive hardware platform: first, to provide a generic device compatible with the different controller types used by different jurisdictions and, second, to automate selection of the FYA left-turn modes based on available gaps in the opposing traffic at intersections acquired in real time from existing sensors in the field. Phase IV provided conclusive field testing and evaluation of the decision support system (DSS), by switching between red and FYA modes in a rational manner consistent with driver expectations and left-turning gap acceptance thresholds. It was also concluded that coordinated signals with long cycle lengths, 3 min and longer, help provide adequate gaps even in heavy traffic patterns since most of the vehicle arrivals are in platoons and at the beginning of the cycle. The analysis showed that the utilization factor for the DSS recommendations for all the intersections ranged between 65% and 75% during peak conditions on weekdays and between 90% and 95% during off-peak conditions and weekends. The total delay in the before study for all the intersections amounted to 737 vehicle-hours and in the after-study was 440 vehicle-hours of delay. An overall reduction of about 40% in delay which confirms the operational benefit of the dynamic FYA DSS. The developed platform is applicable at any four-section head configuration to maximize safety and efficiency of the intersections.