Pancreatic ductal adenocarcinomas concomitant with intraductal papillary mucinous neoplasms of the pancreas: A investigation of those clinicopathological features by analyzing 48 patients who underwent surgery for those lesions.

BACKGROUND: Differences between pancreatic ductal adenocarcinomas (PDACs) concomitant with intraductal papillary mucinous neoplasm (IPMN) (C-PDACs), those without IPMN (NC-PDACs) and invasive cancers derived from IPMN (IC-Ds) have not been fully clarified. METHODS: Forty-eight patients with C-PDAC were included to investigate the differences in 1) clinicopathological features and 2) post-operative courses among the three invasive cancer groups. RESULTS: 1) Characteristics of C-PDACs were mostly similar to those of NC-PDACs; whereas, between C-PDACs and IC-Ds, the rate of mucinous carcinoma (2%/25%, p = 0.003) and pathological stage (IA, 15%/36%, p = 0.033; III, 31%/4%, p = 0.015) significantly differed. Most C-PDACs coexisted with small, multifocal IPMNs without mural nodules. 2) Cumulative 5-year recurrence-free survival (RFS) rate related to extra-pancreatic recurrence was significantly worse in C-PDACs than in IC-Ds (35%/69%, p = 0.008) and was not significantly different between C-PDACs and NC-PDACs (35%/18%). This related to intra-pancreatic recurrence tended to be poor in the order of IC-Ds, C-PDACs, and NC-PDACs (69%/82%/93%). CONCLUSIONS: Because characteristics of IPMNs remarkably differed between C-PDACs and IC-Ds, another algorithm specific to the early detection of C-PDACs is necessary. Appropriate post-operative managements according to the two types of recurrences may contribute to the improvement in the prognoses of C-PDACs/IC-Ds.

Early and long-term clinical outcomes of endoscopic interventions for benign pancreatic duct stricture/obstruction-the possibility of additional clinical effects of endoscopic ultrasonography-guided pancreatic drainage.

OBJECTIVES: For benign pancreatic duct strictures/obstructions (BPDS/O), endoscopic ultrasonography-guided pancreatic drainage (EUS-PD) is performed when endoscopic transpapillary pancreatic drainage (ETPD) fails. We clarified the clinical outcomes for patients with BPDS/O who underwent endoscopic interventions through the era where EUS-PD was available. METHODS: Forty-five patients with BPDS/O who underwent ETPD/EUS-PD were included. We retrospectively investigated overall technical and clinical success rates for endoscopic interventions, adverse events, and clinical outcomes after successful endoscopic interventions. RESULTS: The technical success rates for ETPD and EUS-PD were 77% (35/45) and 80% (8/10), respectively, and the overall technical success rate using two drainage procedures was 91% (41/45). Among the 41 patients who underwent successful endoscopic procedures, the clinical success rates were 97% for the symptomatic patients (35/36). The rates of procedure-related pancreatitis after ETPD and EUS-PD were 13% and 30%, respectively. After successful endoscopic interventions, the cumulative 3-year rate of developing recurrent symptoms/pancreatitis was calculated to be 27%, and only two patients finally needed surgery. Continuous smoking after endoscopic interventions was shown to be a risk factor for developing recurrent symptoms/pancreatitis. CONCLUSIONS: By adding EUS-PD to ETPD, the technical success rate for endoscopic interventions for BPDS/O was more than 90%, and the clinical success rate was nearly 100%. Due to the low rate of surgery after endoscopic interventions, including EUS-PD, for patients with BPDS/O, EUS-PD may contribute to their good clinical courses as a salvage treatment for refractory BPDS/O.

Accurate endoscopic identification of the afferent limb at the Y anastomosis using the fold disruption sign after gastric resection with Roux-en-Y reconstruction.

In patients with Roux-en-Y (RY) reconstruction for gastric resection, the newly defined "fold disruption" (FD) sign can be useful to distinguish the afferent limb from the efferent limb at the Y anastomosis when balloon endoscopy-assisted endoscopic retrograde cholangiopancreatography (BE-ERCP) is performed. The FD sign was defined as endoscopic findings of the internal folds disrupted toward the afferent limb and continued toward the efferent limb at the Y anastomosis. In this prospective observational study, the accuracy of the FD sign was evaluated for those who underwent BE-ERCP after gastric resection with RY reconstruction. Of 28 patients for whom the accuracy could be evaluated among 30 enrolled patients, the afferent limb was identified using the FD sign with 100% accuracy. For the other two patients, the scope could not reach the target lumen due to severe intestinal adhesion in one and reached the target lumen without recognition of the Y anastomosis in the other. There was no patient for whom the FD sign could not be judged for any reason, such as a blurred anastomosis line, unclear folds, sticky discharge and blood coating the surface, when the Y anastomosis was recognized. The FD sign was a highly accurate tool for distinguishing the afferent limb from the efferent limb in patients after gastric resection with RY reconstruction. This study was registered in UMIN (issued ID, UMIN000038326).

Cholangioscopy- versus fluoroscopy-guided transpapillary mapping biopsy for preoperative evaluation of extrahepatic cholangiocarcinoma: a prospective randomized crossover study.

BACKGROUND: To evaluate the lateral extent of extrahepatic cholangiocarcinoma, the value of cholangioscopy-guided mapping biopsy (CMB) compared with that of fluoroscopy-guided mapping biopsy (FMB) remains unknown. The aim of this study was to compare these two techniques. METHODS: In this prospective, randomized, crossover study, both CMB and FMB techniques were performed for all patients in a randomized order. Target sites for the mapping biopsy were determined based on resection lines of possible surgical procedures. At least two biopsy strokes were attempted at each target site. The primary outcome was the rate of site-based successful biopsies, which was defined as acquisition of epithelium-containing material appropriate for diagnosing benignancy/malignancy from each site, regardless of amount of materials obtained from the same site. RESULTS: Between September 2016 and October 2018, 28 patients (16 distal bile duct cancer and 12 perihilar bile duct cancer) were enrolled and divided into two groups of 14 patients: CMB first and FMB first. Although all 118 target sites could be approached using CMB, FMB forceps reached only 71% of them with significantly poor accessibility to the B2/3 confluence. Since several materials were too small and did not contain epithelium, the overall rates of site-based successful biopsies were 78% (92/118) using CMB and 64% (76/118) using FMB (P = 0.031). CONCLUSIONS: The rate of site-based successful biopsies using CMB was significantly higher than that using FMB when evaluated using specimens obtained from several biopsy strokes.

Value of repeated cytology for intraductal papillary mucinous neoplasms of the pancreas with high risk potential of malignancy: Is it a promising method for monitoring a malignant transformation?

OBJECTIVES: The efficacy of and indications for cytological reexamination to detect malignant changes in branch duct type intraductal papillary mucinous neoplasms (BD-IPMNs) have not been studied in detail. We conducted a retrospective study to evaluate the efficacy and indications of cytological reexamination by using pancreatic juice (repeated cytology) for BD-IPMNs. METHODS: Forty-five patients who underwent repeated cytology after a diagnosis of benignancy by using initial cytology were recruited for this study. RESULTS: Thirty-eight patients, excluding 7 patients with lack of surveillance period after the final cytology, were classified into Malignancy (n = 13) and Benignancy groups (n = 25) on the bases of the findings from resected specimens or changes in BD-IPMNs after repeated cytology. The sensitivity and specificity to detect malignant changes in BD-IPMNs by using repeated cytology were 62% and 100%, respectively. For the 12 patients with mural nodules (MNs) ≥ 5 mm (67% of them were malignant), the sensitivity was 50%, whereas, for the 26 patients without MNs ≥ 5 mm (19% of them were malignant), it was 80%. In addition, malignant changes in BD-IPMNs after initial cytology occurred in 62% of the patients with changes in the MNs and 27% of the patients with an increase in the cyst size. CONCLUSION: Repeated cytology can play a role in the determination for surgery even after a diagnosis of benignancy by using initial cytology, especially for BD-IPMNs without MNs ≥5 mm. In addition, changes in the MNs or cyst size may be appropriate indications for repeated cytology.

Delta-toxin from Clostridium perfringens perturbs intestinal epithelial barrier function in Caco-2 cell monolayers.

Clostridium perfringens delta-toxin is a ß-barrel-pore-forming toxin (ß-PFT) and a presumptive virulence factor of type B and C strains, which are causative organisms of fatal intestinal diseases in animals. We showed previously that delta-toxin causes cytotoxicity via necrosis in sensitive cells. Here, we examined the effect of delta-toxin on intestinal membrane integrity. Delta-toxin led to a reduction in transepithelial electrical resistance (TEER) and increased the permeability of fluorescence isothiocyanate-conjugated dextran in human intestinal epithelial Caco-2 cells without changing the tight junction proteins, such as zonula occludens-1 (ZO-1), occludin, and claudin-1. On the other hand, delta-toxin reduced the cellular levels of adherence junction protein E-cadherin before cell injury. A disintegrin and metalloprotease (ADAM) 10 facilitates E-cadherin cleavage and was identified as the cellular receptor for alpha-toxin, a ß-PFT produced by Staphylococcus aureus. ADAM10 inhibitor (GI254023X) blocked the toxin-induced decrease in TEER and cleavage of E-cadherin. Delta-toxin enhanced ADAM10 activity in a dose- and time-dependent manner. Furthermore, delta-toxin colocalized with ADAM10. These results indicated that ADAM10 plays a key role in delta-toxin-induced intestinal injury.

Cellular Uptake of Clostridium botulinum C2 Toxin Requires Acid Sphingomyelinase Activity.

Clostridium botulinum C2 toxin consists of an enzyme component (C2I) and a binding component (C2II). Activated C2II (C2IIa) binds to a cell receptor, giving rise to lipid raft-dependent oligomerization, and it then assembles with C2I. The whole toxin complex is then endocytosed into the cytosol, resulting in the destruction of the actin cytoskeleton and cell rounding. Here, we showed that C2 toxin requires acid sphingomyelinase (ASMase) activity during internalization. In this study, inhibitors of ASMase and lysosomal exocytosis blocked C2 toxin-induced cell rounding. C2IIa induced Ca2+ influx from the extracellular medium to cells. C2 toxin-induced cell rounding was enhanced in the presence of Ca2+ ASMase was released extracellularly when cells were incubated with C2IIa in the presence of Ca2+ Small interfering RNA (siRNA) knockdown of ASMase reduced C2 toxin-induced cell rounding. ASMase hydrolyzes sphingomyelin to ceramide on the outer leaflet of the membrane at acidic pH. Ceramide was detected in cytoplasmic vesicles containing C2IIa. These results indicated that ASMase activity is necessary for the efficient internalization of C2 toxin into cells. Inhibitors of ASMase may confer protection against infection.

Structural and Functional Analyses in Nonarteritic Anterior Ischemic Optic Neuropathy: Optical Coherence Tomography Angiography Study.

BACKGROUND: Retinal and optic disc perfusion in nonarteritic anterior ischemic optic neuropathy (NAION) is incompletely understood. Our aim was to investigate the characteristics of the microvascular structures at the peripapillary area and optic disc, and their associations with retinal structure and function in patients with NAION. METHODS: We conducted a prospective, observational case series study. Thirty-four eyes, consisting of 15 NAION eyes and 19 normal eyes, were included. Optical coherence tomography (OCT) angiography was used to measure the vessel densities in the peripapillary superficial retina and whole-depth mode inside the optic disc. Measurement of circumpapillary retinal nerve fiber layer (cpRNFL) thickness was performed using OCT. Sectorial division analysis of cpRNFL was performed by eliminating the influences of the difference in disc rotation between OCT images and OCT angiography images. RESULTS: The vessel densities of peripapillary retina and inside the optic disc were significantly reduced in the NAION compared to the normal (both P < 0.001). Both the severity of visual field defect and cpRNFL thinning were significantly associated with the peripapillary vessel density (P = 0.006, P = 0.046), but not with the optic disc vessel density (P = 0.981, P = 0.856). cpRNFL and peripapillary vessel density showed reduction predominantly in the superior sectors, corresponding to the visual field defect. However, the correlations showed discrepancy of the sectors. CONCLUSIONS: The microvascular structures in the peripapillary retina and optic disc were reduced, but the cpRNFL thinning was associated with vessel density only in the peripapillary retina, indicating that the vessel densities in the peripapillary retina and optic disc may be differently affected in the pathological process of NAION.

Causes and Prognosis of Unilateral and Bilateral Optic Disc Swelling.

The authors reviewed 93 consecutive cases with optic disc swelling (ODS) to compare clinical manifestations and prognosis among the causes. Among unilateral ODS patients ≥50 years old and without pain, anterior ischaemic optic neuropathy accounted for 87.5%. Furthermore, papilloedema (PE) presented unilateral ODS with an atrophic or hypoplastic disc in the opposite eye. Despite no differences for age and initial visual acuity between PE and pseudopapilloedema, the two main causes of bilateral ODS, some PE patients showed poor visual prognosis. Understanding differences in frequencies and clinical features of ODS related to cause and age group can help to accurately determine cause and predict outcome.

Clostridium perfringens α-Toxin Impairs Lipid Raft Integrity in Neutrophils.

Clostridium perfringens type A, a Gram-positive, anaerobic bacterium, causes gas gangrene. Recently, we reported that C. perfringens α-toxin blocked neutrophil differentiation in an enzyme activity-dependent manner to impair host innate immunity, which should be crucial for the pathogenesis of C. perfringens. However, the detailed mechanism remains unclear. Lipid rafts have been reported to be platforms for signaling molecules involved in the regulation of cell differentiation in many different cell types. In this study, we found that cell surface expression of a lipid raft marker, GM1 ganglioside, decreased in association with neutrophil differentiation by flow cytometry analysis and morphological observation. In vitro treatment of isolated mouse bone marrow cells with α-toxin or an α-toxin variant lacking phospholipase C and sphingomyelinase activities revealed that α-toxin increased the cell surface expression of GM1 ganglioside in an enzyme activity-dependent manner. C. perfringens infection also increased GM1 ganglioside levels in bone marrow myeloid cells. Moreover, treatment of bone marrow cells with methyl-ß-cyclodextrin, a lipid raft-disrupting agent, impaired neutrophil differentiation. Together, our results suggest that the integrity of lipid rafts should be properly maintained during granulopoiesis, and α-toxin might perturb lipid raft integrity leading to the impairment of neutrophil differentiation.

Quantitative comparison of disc rim color in optic nerve atrophy of compressive optic neuropathy and glaucomatous optic neuropathy.

PURPOSE: The purpose was to investigate an objective and quantitative method to estimate the redness of the optic disc neuroretinal rim, and to determine the usefulness of this method to differentiate compressive optic neuropathy (CON) from glaucomatous optic neuropathy (GON). METHODS: In our study there were 126 eyes: 40 with CON, 40 with normal tension glaucoma (NTG), and 46 normal eyes (NOR). Digital color fundus photographs were assessed for the redness of disc rim color using ImageJ software. We separately measured the intensity of red, green, and blue pixels from RGB images. Three disc color indices (DCIs), which indicate the redness intensity, were calculated through existing formulas. RESULTS: All three DCIs of CON were significantly smaller than those of NOR (P < 0.001). In addition, when compared with NTG, DCIs were also significantly smaller in CON (P < 0.05). A comparison of mild CON and mild NTG (mean deviation (MD) > -6 dB), in which the extent of retinal nerve fiber layer thinning is comparable, the DCIs of mild CON were significantly smaller than those of mild NTG (P < 0.05). In contrast, DCIs did not differ between moderate-to-severe stages of CON and NTG (MD ≤ -6 dB), though the retinal nerve fibers of CON were more severely damaged than those of NTG. To differentiate between mild CON and mild NTG, all AUROCs for the three DCIs were above 0.700. CONCLUSIONS: A quantitative and objective assessment of optic disc color was useful in differentiating early-stage CON from GON and NOR.

Identification of the replication region in pBCNF5603, a bacteriocin-encoding plasmid, in the enterotoxigenic Clostridium perfringens strain F5603.

BACKGROUND: Most recent studies of Clostridium perfringens plasmids have focused on toxin-encoding or antibiotic resistance plasmids. To cause intestinal disease, a toxigenic strain must grow in the intestines to levels allowing for sufficient toxin production and this in vivo growth often involves overcoming the normal intestinal microbial population. For this purpose, bacteriocin production might be important. RESULTS: In this study, as the first step in the genetic analysis of a co-existing plasmid with an enterotoxin gene (cpe)-encoding plasmid, the bacteriocin gene-encoding plasmid, pBCNF5603, was completely sequenced. This plasmid has some homology with two previously sequenced C. perfringens plasmids, namely, pCP13 carrying a cpb2 gene and pIP404 carrying a bcn gene. Using recombinant plasmids, the rep gene homologous to the PCP63 gene on pCP13 appeared to be functional. Comparative genomics indicated that the identified rep gene homologs were found on two additional toxin plasmids, pCP-OS1 and pCP-TS1. While functional analysis using recombinant plasmids indicated that pBCNF5603 and pCP13 are likely to be incompatible, the plasmid replication and partitioning region of pBCNF5603 alone was insufficient for stable maintenance of this plasmid. CONCLUSIONS: These findings suggest that pBCNF5603 evolved from recombination events between C. perfringens plasmids and inter-species mobile genetic element(s). In addition, the bcn-encoding plasmid, pBCNF5603, is likely to be included in the Inc family, which includes pCP13 and two variant iota-encoding plasmids. Furthermore, the bcn gene on pBCNF5603 could contribute to gastrointestinal disease induced by enterotoxigenic C. perfringens.

Clostridium perfringens TpeL Induces Formation of Stress Fibers via Activation of RhoA-ROCK Signaling Pathway.

Clostridium perfringens TpeL belongs to a family of large clostridial glucosylating cytotoxins. TpeL modifies Rac1 and Ras subfamily proteins. Herein we report TpeL-induced formation of stress fibers via RhoA-Rho kinase (ROCK) signaling. A recombinant protein (TpeL1-525) derived from the TpeL N-terminal catalytic domain in the presence of streptolysin O (SLO) induced the formation of actin stress fibers in Madin-Darby canine kidney (MDCK) cells in a dose-dependent manner. The RhoA/ROCK pathway is known to control the formation of stress fibers. We examined the role of the RhoA/ROCK pathway in TpeL-induced formation of stress fibers. TpeL1-525-induced formation of stress fibers was inhibited by the ROCK inhibitor, Y27632 and Rho protein inhibitor, C3 transferase. TpeL1-525 activated RhoA and ROCK in a dose-dependent manner. C3 transferase blocked TpeL1-525-induced activation of RhoA and ROCK whereas Y27632 inhibited TpeL-induced activation of ROCK. These results demonstrate for the first time that TpeL induces the formation of stress fibers by activating the RhoA/ROCK signaling pathway.

Plain computed tomography for differentiating neoplastic and non-neoplastic pedunculated gallbladder polyps.

AIMS: Surgery is recommended for large pedunculated gallbladder polyps (PGPs), which measure 10 mm or more in size, because they tend to be neoplastic polyps (NPs), such as adenomas and adenocarcinomas. However, after resection, they are often found to be non-neoplastic polyps (non-NPs). This study aimed to evaluate the usefulness of plain CT in distinguishing NPs from non-NPs. METHODS: Of the 80 patients who underwent cholecystectomy for PGPs ( 10 mm between January 2008 and February 2021, 46 who underwent plain and contrast-enhanced CT (CE-CT) before resection were included in this study. We retrospectively assessed the polyp detection rate (PDR) using CT and calculated the difference in the CT values between PGPs and the surrounding bile. RESULTS: Twenty-one patients had NPs (12 adenomas, 5 carcinomas in adenoma, and 4 adenocarcinomas). The others were non-NPs (24 cholesterol polyps and one hyperplastic polyp). The PDR using plain CT was significantly higher in the NP group than in the non-NP group (38% (8/21) vs. 0% (0/25), p <0.01). The sensitivity, specificity, positive predictive value, negative predictive value, and diagnostic accuracy of NPs were 38%, 100%, 100%, 66%, and 72%, respectively. The difference in the CT values between PGPs and the surrounding bile was significantly larger in the NP group than in the non-NP group (14.12 ± 11.38 HU, 5.04 ± 6.15 HU, p <0.01). CONCLUSIONS: PGPs detected using plain CT had a high probability of being NPs. Plain CT is therefore considered to be useful for differentiating NPs from non-NPs.

Prophylactic endoscopic transpapillary gallbladder stenting to prevent acute cholecystitis induced after metallic stent placement for malignant biliary strictures: a retrospective study, Japan.

Background/Aims: Endoscopic biliary drainage using self-expandable metallic stents (SEMSs) for malignant biliary strictures occasionally induces acute cholecystitis (AC). This study evaluated the efficacy of prophylactic gallbladder stents (GBS) during SEMS placement. Methods: Among 158 patients who underwent SEMS placement for malignant biliary strictures between January 2018 and March 2023, 30 patients who attempted to undergo prophylactic GBS placement before SEMS placement were included. Results: Technical success was achieved in 21 cases (70.0%). The mean diameter of the cystic duct was more significant in the successful cases (6.5 mm vs. 3.7 mm, p<0.05). Adverse events occurred for 7 patients (23.3%: acute pancreatitis in 7; non-obstructive cholangitis in 1; perforation of the cystic duct in 1 with an overlap), all of which improved with conservative treatment. No patients developed AC when the GBS placement was successful, whereas 25 of the 128 patients (19.5%) without a prophylactic GBS developed AC during the median follow-up period of 357 days (p=0.043). In the multivariable analysis, GBS placement was a significant factor in preventing AC (hazard ratio, 0.61; 95% confidence interval, 0.37-0.99; p=0.045). Conclusions: GBS may contribute to the prevention of AC after SEMS placement for malignant biliary strictures.

Methylation of breast cancer susceptibility gene 1 (BRCA1) predicts recurrence in patients with curatively resected stage I non-small cell lung cancer.

BACKGROUND: Even after early detection and curative resection of early stage non-small cell lung cancer (NSCLC), a significant fraction of patients develop recurrent disease. Molecular biomarkers that can predict the risk of recurrence thus need to be identified to improve clinical outcomes. METHODS: Using the methylation-specific polymerase chain reaction assay, promoter methylation of the breast cancer susceptibility gene 1 (BRCA1) was assessed in cancer tissues from 70 patients with curatively resected stage I NSCLC. The clinical relevance of BRCA1 methylation status was evaluated in terms of outcome of the disease. RESULTS: Methylation of the BRCA1 promoter was detected in 13 of 70 patients (18.6%). Multiple logistic regression analysis revealed that BRCA1 methylation was an independent risk factor for recurrence (P = .0197) and that patients with BRCA1 methylation demonstrated significantly poorer recurrence-free survival compared to those without (P = .0139). Cox's proportional hazard regression analysis revealed that BRCA1 methylation was an independent risk factor for recurrence-free survival (P = .0155). CONCLUSIONS: Methylated BRCA1 can be a potential biomarker that predicts the prognosis after curative resection of stage I NSCLC. Considering that BRCA1 plays a role in chemotherapy-induced apoptosis, it is plausible that identification of methylated BRCA1 could provide information that is clinically relevant to tailored adjuvant therapy.

Bacillus cereus sphingomyelinase recognizes ganglioside GM3.

Sphingomyelinase (SMase) from Bacillus cereus (Bc-SMase) hydrolyzes sphingomyelin (SM) to phosphocholine and ceramide in a divalent metal ion-dependent manner, and is a virulence factor for septicemia. Bc-SMase has three characteristic sites, viz., the central site (catalytic site), side-edge site (membrane binding site), and ß-hairpin region (membrane binding site). Here, we show that the ß-hairpin directly binds to gangliosides, especially NeuAcα2-3Galß1-4Glcß1-1ceramide (GM3) through a carbohydrate moiety. Neuraminidase inhibited the binding of Bc-SMase to mouse peritoneal macrophages in a dose-dependent manner. SPR analysis revealed that the binding response of Bc-SMase to liposomes containing GM3 was about 15-fold higher than that to liposomes lacking GM3. Moreover, experiments with site-directed mutants indicated that Trp-284 and Phe-285 in the ß-hairpin play an important role in the interaction with GM3. The binding of W284A and F285A mutant enzymes to mouse macrophages decreased markedly in comparison to the binding by wild-type enzymes. Therefore, we conclude that GM3 is the primary cellular receptor for Bc-SMase, and that the ß-hairpin region is the tethering region for gangliosides.

Morphologic and functional changes in retinal vessels associated with branch retinal vein occlusion.

OBJECTIVE: To study the morphologic and functional changes in retinal veins of eyes affected with branch retinal vein occlusion (BRVO) by thin sectioning with optical coherence tomography (OCT). DESIGN: Prospective, observational, cross-sectional study. PARTICIPANTS: Twenty-five consecutive patients (25 eyes) with acute BRVO. METHODS: Major retinal veins, arteries, and arteriovenous (A/V) crossing were examined by sequential thin sectioning by Spectralis HRA+OCT (Heidelberg Engineering, Heidelberg, Germany). The retinal blood flow was mimicked in vitro and scanned with Spectralis HRA+OCT. MAIN OUTCOME MEASURES: Morphologic characteristics of normal and BRVO-affected retinal vessels seen in OCT sections. RESULTS: Cross-sectional OCT images revealed physiologic retinal vessels as oval configurations with 4 distinctive hyperreflectivities in a line. The vessel walls showed the innermost and outermost hyperreflectivity, and the blood flow showed internal paired hyperreflectivities with an hourglass shape. No eye with disturbed blood flow due to BRVO showed this internal hyperreflectivity pattern. In vitro, OCT sections of the blood within the glass tube without flow showed homogeneous reflectivities. Increased blood flow velocity resulted in the development of heterogeneous internal reflectivity and hourglass-shaped hyperreflectivities. In all eyes with acute BRVO, sequential sectioning with OCT visualized 3-dimensional vascular architecture and the intravascular conditions at the A/V crossing. At the affected A/V crossing, arterial overcrossing was seen in 17 eyes and venous overcrossing was seen in 8 eyes. In eyes with arterial overcrossing, the retinal vein seemed to run deep under the artery at the A/V crossing, and the venous lumen often appeared to be preserved even at the A/V crossing. In all eyes with venous overcrossing, the retinal vein appeared to be compressed and choked between the internal limiting membrane and the arterial wall at the A/V crossing. Optical coherence tomography sectioning showed intravenous thrombi in 21 eyes, and the thrombi were detected downstream of the A/V crossing in all the cases. The detection of thrombus was significantly associated with ischemic pattern in BRVO (P=0.036). CONCLUSIONS: In eyes with BRVO, sequential thin sections with OCT visualized 3-dimensional retinal vasculature. The present OCT findings suggest that BRVO may occur by 2 different mechanisms, depending on the relative anatomic positions of the crossing vessels. FINANCIAL DISCLOSURE(S): The author(s) have no proprietary or commercial interest in any materials discussed in this article.

Prospective feasibility study on the efficacy and safety of a novel spiral dilator for endoscopic ultrasound-guided drainage.

Objectives: A difficult step in endoscopic ultrasound (EUS)-guided drainage procedures is dilation of the puncture tract before stent deployment. The efficacy and safety of a novel spiral dilator, Tornus ES, for EUS-guided drainage were investigated in this study. Methods: This study was conducted as a prospective, single-arm, observational study at Sendai City Medical center. Dilation of the puncture tract using a spiral dilator was attempted for all EUS-guided drainage cases. The primary outcome was the technical success rate which was defined as successful stent placement in the puncture tract. Secondary outcomes were the success rate of dilation using a spiral dilator, procedure time, and adverse events related to the procedures. Results: A total of 10 patients were enrolled between January and March 2022. Seven patients underwent EUS-guided biliary drainage (hepaticogastrostomy for six and hepaticojejunostomy for one), and the remaining three patients underwent EUS-guided gallbladder drainage. The technical success rate and the success rate of dilation using a spiral dilator were both 100%. The mean procedure time was 27 min. No adverse events related to the procedure occurred in all cases. Conclusions: Dilation of the puncture tract using a spiral dilator was effective and safe and might make it easier to perform EUS-guided drainage.

Treatment Strategy for Acute Cholecystitis Induced by a Metallic Stent Placed in Malignant Biliary Strictures: Role of Percutaneous Transhepatic Gallbladder Aspiration.

Objective The present study evaluated the strategic role of percutaneous transhepatic gallbladder aspiration (PTGBA) for acute cholecystitis (AC) induced by a metallic stent (MS) placed in a malignant biliary stricture in comparison with percutaneous transhepatic gallbladder drainage (PTGBD). Methods The treatment outcomes for 31 patients who underwent PTGBA as the initial intervention for MS-induced AC were evaluated and compared with those for 12 who underwent PTGBD. Results The technical success rate was 100% for both groups. PTGBA was ineffective for 11 patients, all of whom recovered with additional intervention, whereas PTGBD was effective for all patients except for 1 who died of sepsis (clinical success rate, 65% vs. 90%, p=0.16). Adverse events (AEs) were observed in only 1 case (3%) in the PTGBA group (mild bile peritonitis). Among the clinically effective cases, AC recurred in 20% of the PTGBA group and 33% of the PTGBD group (p=0.72). In the PTGBA group, the clinical success rate was significantly higher for patients without cancer invasion to a feeding artery of the gallbladder than in those with invasion (75% without invasion vs. 29% with invasion; p=0.036). According to the multivariate analysis, this factor was an independent factor for clinical success of PTGBA (odds ratio, 9.27; p=0.040). Conclusion Although the clinical success rate of PTGBA for MS-induced AC was lower than that of PTGBD, PTGBA remains a viable option because of its safety and procedural simplicity, especially for cases without tumor invasion to a feeding artery.