Unilateral drainage and chemotherapy prolong the patency of a plastic stent placed above the sphincter of Oddi in patients with malignant hilar biliary obstruction.

Objectives: To evaluate the results of inside stent therapy for unresectable malignant hilar biliary obstruction and identify factors related to stent patency duration. Methods: Of 44 patients who underwent initial inside-stent placement above the sphincter of Oddi from April 2017 to December 2022, 42 with the resolution of jaundice (clinical success rate, 95.5%) were retrospectively analyzed. Univariate and multivariate logistic regression analysis identified factors associated with stent patency duration. Results: Univariate analysis revealed significant differences in the drainage method (406 days for unilateral drainage vs. 305 days for bilateral drainage of the right and left liver lobes, p = 0.022) with or without chemotherapy (406 days with vs. 154 days without, p = 0.038). Multivariate analysis (Cox proportional hazards analysis) revealed similar results, with unilateral drainage (p = 0.031) and chemotherapy (p = 0.048) identified as independent factors associated with prolonged stent patency. Early adverse events were observed in two patients (4.8%; one cholangitis, one pancreatitis). Conclusions: Inside-stent therapy was safely performed in patients with malignant hilar biliary obstruction. Simple unilateral drainage and chemotherapy may prolong stent patency.

[A case of metronidazole-induced encephalopathy that is difficult to differentiate from Wernicke encephalopathy].

Herein, we present the case of a 76-year-old man diagnosed with an iliopsoas abscess 3 months prior and consequently administered metronidazole. The patient visited our facility complaining of difficulty in speaking and feeling unsteady when walking. Neurological findings showed dysarthria, nystagmus, and bilateral cerebellar ataxia. Head MRI-FLAIR demonstrated symmetrical hyperintensities in the bilateral cerebellar dentate nuclei, red nucleus, periaqueductal of the midbrain, periventricular third ventricle, and the corpus callosum. Although Wernicke's encephalopathy was among the differential diagnoses based on the imaging findings, the thiamine level was normal and improvement in symptoms and hyperintensity on FLAIR within 5 days of discontinuing metronidazole led to the diagnosis of metronidazole-induced encephalopathy. Although there were many similarities in the imaging findings of metronidazole-induced encephalopathy and Wernicke's encephalopathy, Metronidazole-induced encephalopathy should be initially considered when midbrain red nucleus lesions are observed.

Extracellular vesicle-mediated secretion of chlorophyll biosynthetic intermediates in the cyanobacterium Leptolyngbya boryana.

Extracellular vesicles (EVs) are derived from the outer membrane (OM) in Gram-negative bacteria and have diverse physiological functions. EV-mediated secretion of monovinyl protochlorophyllide (MV-Pchlide), the chlorophyll a (Chl) biosynthetic intermediate, was previously reported in a mutant lacking dark-operative Pchlide reductase in the cyanobacterium Leptolyngbya boryana. This study showed a detailed characterization of EVs from the wild-type (WT) of L. boryana grown under photoautotrophic and dark heterotrophic conditions, focusing on the accumulation of Chl intermediates. WT L. boryana cells produce two types of EVs, low-density EVs (L-EVs) and high-density EVs (H-EVs), both under light and dark conditions. L-EVs and H-EVs showed distinct morphological features and protein compositions. L-EVs from cells grown under both light and dark conditions commonly contained carotenoids, ketomyxol glycoside, and zeaxanthin, as major pigments. Based on the protein compositions of EVs and other cellular membrane fractions, L-EVs and H-EVs are probably derived from low-density OM and high-density OM interacting with cell walls, respectively. Fluorescence detection of pigments was applied to EVs, and the two Chl intermediates, protoporphyrin IX and protoporphyrin IX monomethyl ester, were commonly detected in both L-EVs from light- and dark-grown cells, whereas L-EVs from dark-grown cells contained additional MV-Pchlide, MV-protopheophorbide, and pheophorbide. The pigment ratios of L-EVs to the total culture medium of the Chl intermediates were much higher than those of carotenoids, suggesting an active transport of the Chl intermediates from the thylakoid membrane to L-EVs. Cyanobacterial EVs may play a novel role in alleviating the accumulation of Chl intermediates in cells. (248 words).

Extracorporeal membrane oxygenation-facilitated palliative radiotherapy for severe airway obstruction due to lung cancer: A case report.

Background: The use of venovenous extracorporeal membrane oxygenation (VV-ECMO), particularly during radiotherapy, for severe malignant central airway obstruction has rarely been reported. Case Presentation: A 47-year-old female presented to our emergency department with severe respiratory distress. Given her medical history, she was initially diagnosed with asthma. Despite initial treatment, which included intubation, her condition deteriorated, necessitating VV-ECMO. Computed tomography performed following the initiation of VV-ECMO revealed extensive lung cancer involving both bronchial types. Radiotherapy while on VV-ECMO led to a significant reduction in tumor size, allowing for the weaning of ECMO support and successful extubation. Conclusion: Malignant central airway obstruction is life-threatening. Our case demonstrates the efficacy of combining VV-ECMO with radiotherapy when conventional therapies fail. Further research is necessary to validate and explore this novel approach's implications.

Risk of stricture after endoscopic submucosal dissection in the cervical esophagus and efficacy of local steroid injection for stricture prevention.

BACKGROUND AND AIMS: There is a high incidence of stricture after endoscopic submucosal dissection (ESD) for cervical esophageal cancer. We aimed to elucidate the risk factors for stricture and evaluate the efficacy of steroid injection for stricture prevention in the cervical esophagus. METHODS: We retrospectively analyzed 100 patients who underwent ESD for cervical esophageal cancer to: (1) identify the factors associated with stricture among patients who did not receive steroid injection; (2) compare the incidence of stricture between patients with and without steroid injection. RESULTS: Among 48 patients who did not receive steroid injection, there were significant differences in tumor size (P = .026), resection time (P = .028), and circumferential extent of the mucosal defect (P = .005) between patients with stricture (n = 5) and without stricture (n = 43). Compared with patients without steroid injection, patients with steroid injection had a significantly lower incidence of stricture when the post-ESD mucosal defect was < 3/4 and ≥ 1/2 (40% versus 8%, P = .039). As for the patients with a post-ESD mucosal defect of ≥ 3/4 (n = 13), local steroid injection was performed for all the patients, and 6 patients (46%) developed stricture. CONCLUSIONS: Patients who underwent ≥ 1/2 circumferential resection were at high risk of cervical esophageal stricture. Steroid injection had a stricture-prevention effect in patients with < 3/4 and ≥ 1/2 circumferential resection, but seemed to be insufficient in preventing stricture in patients with ≥ 3/4 circumferential resection.

Recurrent episodes of atrioventricular nodal reentrant tachycardia: Sites of ablation success, ablation endpoint, and primary culprits for recurrence.

Background: Atrioventricular nodal reentrant tachycardia (AVNRT) sometimes recurs even after anatomical slow pathway (SP) ablation targeting the rightward inferior extension (RIE). This multicenter study aimed to determine the reasons for AVNRT recurrence. Methods and Results: Forty-six patients were treated successfully for recurrent AVNRT. Initial treatment was for 38 slow-fast AVNRTs, 3 fast-slow AVNRTs, 2 slow-slow AVNRTs, 2 slow-fast and fast-slow AVNRTs, and 1 noninducible AVNRT. All initial treatments were of RF application to the RIE; SP elimination was achieved in 11, dual AVN physiology was seen in 29, and AVNRT remained inducible in 5. The recurrent AVNRTs included 34 slow-fast AVNRTs, 6 fast-slow AVNRTs, 3 slow-slow AVNRTs, 2 slow-fast and fast-slow AVNRTs, and 1 slow-fast and slow-slow AVNRTs. Successful ablation site was within the RIE in 39 and left inferior extension in 7. In 30 of 39, the successful RIE site was in the same area or higher than that of the initial procedure. Conclusion: For a high majority (around 85%) of patients in whom AVNRT recurs after initial ablation success, the site of a second successful procedure will be within the RIE even though the RIE was originally targeted. Furthermore, a high majority (around 86%) of sites of successful ablation will be higher than those originally targeted.

Four-Stage Rocket technique: A novel strategy for lead extractions using laser sheaths from the femoral vein.

INTRODUCTION: Transvenous lead extractions (TLEs) for cardiac implantable electronic device complications often encounter difficulties with strong adhesions to the myocardium or vessels. In this report, we introduce a novel "Four-Stage Rocket" technique for effective TLE in cases where conventional methods fail. METHODS AND RESULTS: Two challenging cases where conventional TLE methods failed were treated using a combination of four devices: Needle's Eye Snare, Agilis NxT Steerable Introducer, GlideLight Laser sheath, and GORE® DrySeal Flex Introducer sheath, employed via the inferior vena cava. The "Four-Stage Rocket" technique successfully detached firmly adhered leads near the tricuspid valve annulus, where the traditional superior vena cava approach was inadequate. CONCLUSION: The "Four-Stage Rocket" technique offers a potential alternative in complex TLE cases, aligning the laser direction with the adhesion detachment and reducing the tissue damage risk.

"Honey pot"-like lesion formation: Impact of catheter contact angle on lesion formation by novel diamond-embedded temperature-controlled ablation catheter in a porcine experimental model.

BACKGROUND: Novel diamond-embedded catheter enables precise temperature-controlled ablation. However, the effects of contact angle on lesion formation of this catheter are poorly understood. OBJECTIVE: The purpose of this study was to evaluate lesion formation using the temperature-controlled ablation catheter embedded with diamond at different angles in a porcine experimental model. METHODS: Freshly sacrificed porcine hearts were used. Radiofrequency catheter ablation was performed at 50 W for 15 seconds at an upper temperature setting of 60°C. The contact force (5g, 10g, 30g) and catheter contact angles (30°, 45°, 90°) were changed in each set (n = 13 each). Surface width, maximum lesion width, lesion depth, surface area, distance from the distal edge to the widest area, and impedance drop were evaluated. RESULTS: Surface width and maximum lesion width were longer at 30° than at 90° (P <.05). There were no significant differences in the lesion depth by catheter angle except at 30g. Surface area was larger at 30° than at 90° (P <.05). Distance from the distal edge to the widest area was longer at 30° than at 90° (P <.05). There were no significant differences in impedance drop according to catheter angle. CONCLUSION: With diamond-embedded temperature-controlled ablation catheters, lesion width increased at a shallower contact angle, whereas lesion depth did not. Surface area also increased at a shallower contact angle. This catheter created a large ablation lesion on the proximal side of the catheter, which looked like a "honey pot."

Postoperative intravenous patient-controlled analgesia improves pain management after subcutaneous implantable defibrillator implantation.

Objective: Postoperative pain is a major issue with subcutaneous implantable cardioverter defibrillators (S-ICD). In 2020, we introduced intravenous patient-controlled analgesia (IV-PCA) in addition to the conventional, request-based analgesia for postoperative pain control in S-ICD. To determine the effect and safety, we quantitatively assessed the effect of IV-PCA after S-ICD surgery over conventional methods. Methods: During the study period, a total of 113 consecutive patients (age, 50.1 ± 15.5 years: males, 101) underwent a de novo S-ICD implantation under general anesthesia. While the postoperative pain was addressed with either request-based analgesia (by nonsteroid anti-inflammatory drugs, N = 68, dubbed as "PCA absent") or fentanyl-based IV-PCA in addition to the standard care (N = 45, dubbed as "PCA present"). The degree of postoperative pain from immediately after surgery to 1 week were retrospectively investigated by the numerical rating scale (NRS) divided into four groups at rest and during activity (0: no pain, 1-3: mild pain, 4-6: moderate pain, 7-10: severe pain). Results: Although IV-PCA was removed on Day 1, it was associated with continued better pain control compared to PCA absent group. At rest, the proportion of patients expressing pain (mild or more) was significantly lower in the PCA present group from Day 0 to Day 4. In contrast to at rest, a better pain control continued through the entire study period of 7 days. No serious adverse events were observed. A few patients experienced nausea in both groups and the inter-group difference was not found significant. Conclusion: IV-PCA suppresses postoperative pain in S-ICD without major safety concerns.

Comparison of the electrophysiological properties of the pulmonary veins between paroxysmal and persistent atrial fibrillation.

Background: The role of the pulmonary veins (PVs) as triggers in atrial fibrillation (AF) is well-known; however, their detailed electrophysiological properties have not been thoroughly examined. Objective: This study aimed to investigate the electrophysiological properties of the PVs between paroxysmal AF (pAF) and persistent AF (perAF). Methods: Prior to catheter ablation in patients with pAF (n = 51) and perAF (n = 41), a voltage map of the left atrium and PVs was created under sinus rhythm, and the area of the myocardial sleeves in the PVs and their electrophysiological characteristics, including the pacing threshold and effective refractory period (ERP), were compared between the two groups. Results: Compared with perAF, the myocardial sleeves of PVs for pAF were significantly larger for all PVs. The ERP for perAF was significantly shorter than that for pAF for all PVs. The pacing threshold for perAF was significantly higher than that for pAF for the right and left superior PVs. Conclusion: In patients with perAF, a decrease in the normal myocardial sleeves and a shortening of the ERP were observed for all PVs. Those changes in the electrophysiological properties of the PVs might be related to the persistence of AF.

Systematic observation-based diagnosis of atrioventricular nodal reentrant tachycardia with a bystander concealed nodoventricular pathway.

Background: This study aimed to establish a systematic method for diagnosing atrioventricular nodal reentrant tachycardia (AVNRT) with a bystander concealed nodoventricular pathway (cNVP). Methods: We analyzed 13 cases of AVNRT with a bystander cNVP, 11 connected to the slow pathway (cNVP-SP) and two to the fast pathway (cNVP-FP), along with two cases of cNVP-related orthodromic reciprocating tachycardia (ORT). Results: The diagnostic process was summarized in three steps. Step 1 was identification of the presence of an accessory pathway by resetting the tachycardia with delay (n = 9) and termination without atrial capture (n = 4) immediately after delivery of a His-refractory premature ventricular contraction (PVC). Step 2 was exclusion of ORT by atrio-His block during the tachycardia (n = 4), disappearance of the reset phenomenon after the early PVC (n = 7), or dissociation of His from the tachycardia during ventricular overdrive pacing (n = 1). Moreover, tachycardia reset/termination without the atrial capture (n = 2/2) 1 cycle after the His-refractory PVC was specifically diagnostic. Exceptionally, the disappearance of the reset phenomenon was also observed in the two cNVP-ORTs. Step 3 was verification of the AVN as the cNVP insertion site, evidenced by an atrial reset/block preceding the His reset/block in fast-slow AVNRT with a cNVP-SP and slow-fast AVNRT with a cNVP-FP or His reset preceding the atrial reset in slow-fast AVNRT with a cNVP-SP. Conclusion: AVNRT with a bystander cNVP can be diagnosed in the three steps with few exceptions. Notably, tachycardia reset/termination without atrial capture one cycle after delivery of a His-refractory PVC is specifically diagnostic.

Influence of the irrigation flow pattern and catheter tip design on the lesion formation: an ex vivo experimental model.

BACKGROUND: Lesion formation during catheter ablation is influenced by the power, contact force (CF), time, and catheter stability. However, the influence of the irrigation effects on lesion formation remains unknown. METHODS: An ex vivo experiment using conductive gel was performed. Using three different catheter designs (TactiFlex ™ SE [TF], IntellaNav MiFi ™ OI [MiFi], QDOT MICRO™ [QDOT]), a cross-sectional analysis of the lesion size and surface lesion type of 10g/40W lesions with a combination of various ablation times was performed in protocol 1. A longitudinal analysis (combination of various powers [30, 40, and 50W] and various ablation times with a 10g setting) was performed to investigate the influence of the auto-regulated irrigation system (QDOT) on lesion formation in protocol 2. RESULTS: The lesion formation with the QDOT catheter tended to create larger ablation lesions, while that with the TF catheter created smaller lesions than the other catheters. The lesion surface characteristics were divided into two patterns: ring (MiFi catheter and QDOT) and crescent (TF) patterns. The auto-regulated irrigation system did not influence the lesion formation, and the relationship between the lesion formation and RF energy exhibited similar changes regardless of the ablation power setting. CONCLUSION: The lesion formation and lesion surface characteristics differed among the different irrigation tip designs. An auto-regulated irrigation system did not affect the lesion creation or surface lesion characteristics. Care should be given to the inter-product differences in the lesion characteristics during RF catheter ablation, partly due to the irrigation flow control and tip design.

Does the same lesion index mean the same efficacy and safety profile: influence of the differential power, time, and contact force on the lesion size and steam pops under the same lesion index.

BACKGROUND: The lesion index (LSI) helps predict the lesion size and is widely used in ablation of various types of arrhythmias. However, the influence of the ablation settings on the lesion formation and incidence of steam pops under the same LSI value remains unclear. METHODS: Using a contact force (CF) sensing catheter (TactiCath™) in an ex vivo swine left ventricle model, RF lesions were created with a combination of various power steps (30 W, 40 W, 50 W) and CFs (10 g, 20 g, 30 g, 40 g, 50 g) under the same LSI values (5.2 and 7.0). The correlation between the lesion formation and ablation parameters was evaluated. RESULTS: Ninety RF lesions were created under a target LSI value of 5.2, and eighty-four were developed under a target LSI value of 7.0. In the LSI 5.2 group, the resultant lesion size widely varied according to the ablation power, and a multiple regression analysis indicated that the ablation energy delivered was the best predictor of the lesion formation. To create a lesion depth > 4 mm, an ablation energy of 393 J is the best cutoff value, suggesting a possibility that ablation energy may be used as a supplemental marker that better monitors the progress of the lesion formation in an LSI 5.2 ablation. In contrast, such inconsistency was not obvious in the LSI 7.0 group. Compared with 30 W, the 50-W ablation exhibited a higher incidence of steam pops in both the LSI 5.2 and 7.0 groups. CONCLUSIONS: The LSI-lesion size relationship was not necessarily consistent, especially for an LSI of 5.2. To avoid any unintentional, weak ablation, the ablation energy may be a useful supportive parameter (393 J as a cutoff value for a 4-mm depth) during ablation with an LSI around 5.2. Thanks to a prolonged ablation time, the LSI-lesion size relationship is consistent for an LSI of 7.0. However, it is accompanied by a high incidence of steam pops. Care should be given to the ablation settings even when the same LSI value is used.

Age-dependent contribution of intrinsic mechanisms to sinoatrial node function in humans.

Average beat interval (BI) and beat interval variability (BIV) are primarily determined by mutual entrainment between the autonomic-nervous system (ANS) and intrinsic mechanisms that govern sinoatrial node (SAN) cell function. While basal heart rate is not affected by age in humans, age-dependent reductions in intrinsic heart rate have been documented even in so-called healthy individuals. The relative contributions of the ANS and intrinsic mechanisms to age-dependent deterioration of SAN function in humans are not clear. We recorded ECG on patients (n = 16 < 21 years and n = 23 41-78 years) in the basal state and after ANS blockade (propranolol and atropine) in the presence of propofol and dexmedetomidine anesthesia. Average BI and BIV were analyzed. A set of BIV features were tested to designated the "signatures" of the ANS and intrinsic mechanisms and also the anesthesia "signature". In young patients, the intrinsic mechanisms and ANS mainly contributed to long- and short-term BIV, respectively. In adults, both ANS and intrinsic mechanisms contributed to short-term BIV, while the latter also contributed to long-term BIV. Furthermore, anesthesia affected ANS function in young patients and both mechanisms in adult. The work also showed that intrinsic mechanism features can be calculated from BIs, without intervention.

Venous thoracic outlet syndrome, as a pitfall for cardiac implantable electronic device implantations.

The subclavian vein is typically used in cardiovascular implantable electronic device (CIED) implantations. External stress on the subclavian vein can lead to lead-related complications. There are several causes of this stress, such as frequent upper extremity movements or external injury. Venous thoracic outlet syndrome (TOS) can also become the cause of external lead stress. However, the diagnosis of venous TOS can be challenging because subclavian venography can appear normal at first glance. We present a unique case of a device infection in a patient with venous TOS. A careful observation of the imaging studies is vital for diagnosing venous TOS and a leadless pacemaker implantation could be an alternative therapeutic option.

Brain activity in response to food images in patients with irritable bowel syndrome and functional dyspepsia.

BACKGROUND: Functional dyspepsia (FD) and irritable bowel syndrome (IBS) are caused and exacerbated by consumption of fatty foods. However, no study has evaluated brain activity in response to food images in patients with disorders of gut-brain interaction (DGBI). This study aimed to compare food preference and brain activity when viewing food images between patients with DGBI and healthy controls. METHODS: FD and IBS were diagnosed using the ROME IV criteria. Food preference was assessed using a visual analog scale (VAS). Brain activity in the prefrontal cortex (PFC) in response to food images was investigated using functional near-infrared spectroscopy (fNIRS). RESULTS: Forty-one patients were enrolled, including 25 with DGBI. The mean VAS scores for all foods (controls vs. FD vs. IBS: 69.1 ± 3.3 vs. 54.8 ± 3.8 vs. 62.8 ± 3.7, p = 0.02), including fatty foods (78.1 ± 5.4 vs. 43.4 ± 6.3 vs. 64.7 ± 6.1, p < 0.01), were the lowest in patients with FD among all groups. Patients with FD had significantly higher brain activity in the left PFC than those with IBS and healthy controls (mean z-scores in controls vs. FD vs. IBS: - 0.077 ± 0.03 vs. 0.125 ± 0.04 vs. - 0.002 ± 0.03, p < 0.001). CONCLUSIONS: Patients with DGBI, particularly those with FD, disliked fatty foods. The brain activity in patients with DGBI differed from that in healthy controls. Increased activity in the PFC of patients with FD was confirmed.