What is the appropriate method of pathological specimen collection for cholangiocarcinoma detection in primary sclerosing cholangitis?

BACKGROUND: In primary sclerosing cholangitis (PSC), it is important to understand the cholangiographic findings suggestive of malignancy, but it is difficult to determine whether cholangiocarcinoma is present due to modifications caused by inflammation. This study aimed to clarify the appropriate method of pathological specimen collection during endoscopic retrograde cholangiopancreatography for surveillance of PSC. METHODS: A retrospective observational study was performed on 59 patients with PSC. The endpoints were diagnostic performance for benign or malignant on bile cytology and transpapillary bile duct biopsy, cholangiographic findings of biopsied bile ducts, diameters of the strictures and upstream bile ducts, and their differences. RESULTS: The sensitivity (77.8% vs. 14.3%, P = 0.04), specificity (97.8% vs. 83.0%, P = 0.04), and accuracy (94.5% vs. 74.1%, P = 0.007) were all significantly greater for bile duct biopsy than for bile cytology. All patients with cholangiocarcinoma with bile duct stricture presented with dominant stricture (DS). The diameter of the upstream bile ducts (7.1 (4.2-7.2) mm vs. 2.1 (1.2-4.1) mm, P < 0.001) and the diameter differences (6.6 (3.1-7) mm vs. 1.5 (0.2-3.6) mm, P < 0.001) were significantly greater in the cholangiocarcinoma group than in the noncholangiocarcinoma group with DS. For diameter differences, the optimal cutoff value for the diagnosis of benign or malignant was 5.1 mm (area under the curve = 0.972). CONCLUSION: Transpapillary bile duct biopsy should be performed via localized DS with upstream dilation for the detection of cholangiocarcinoma in patients with PSC. Especially when the diameter differences are greater than 5 mm, the development of cholangiocarcinoma should be strongly suspected.

Monoclonal Antibodies Against Mature Interleukin-18 Ameliorate Colitis and Repair Goblet Cell Function.

BACKGROUND: Numerous biological interventions and small molecules are used to treat Crohn's disease; however, the effectiveness of these treatments varies largely. Non-responsiveness to biological therapies is associated with interleukin (IL)-18 gene polymorphisms and high IL-18 expression has been implicated in the pathogenesis of Crohn's disease. AIMS: The aim of this study was to elucidate the expression of precursor and mature IL-18 in patients with Crohn's disease who exhibited varied responses to cytokine-targeted treatments and determine whether selective inhibition of mature IL-18 offers a novel therapeutic avenue. METHODS: We generated a monoclonal antibody that specifically recognizes the neoepitope of caspase-cleaved mature IL-18. Expression of precursor and mature IL-18 was analyzed in patients with Crohn's disease. Anti-mature IL-18 monoclonal antibodies were intraperitoneally administered in an acute colitis mouse model, and the disease activity index, body weight loss, tissue pathology, proinflammatory cytokine expression, goblet cell function, and microbiota composition were assessed. RESULTS: Precursor and mature IL-18 expression was upregulated and goblet cell function was impaired in patients with Crohn's disease who were unresponsive to biological therapies. Administration of anti-mature IL-18 antibodies ameliorated induced colitis by repairing goblet cell function and restoring the mucus layer. CONCLUSIONS: The newly developed monoclonal antibody holds promise as a therapeutic alternative for Crohn's disease.

A prospective study on the histological evaluation of type 1 autoimmune pancreatitis using endoscopic ultrasound-guided fine needle biopsy with a 19-gauge Franseen needle.

BACKGROUND/PURPOSE: To assess the diagnostic efficacy and safety of endoscopic ultrasound-guided fine needle biopsy (EUS-FNB) using a 19-gauge Franseen needle for autoimmune pancreatitis (AIP). METHODS: Twenty patients suspected of having type 1 AIP were prospectively enrolled and underwent EUS-FNB with a 19-gauge Franseen needle. Their data were compared with those of historical controls: a total of 29 type 1 AIP patients had EUS-FNB with a 22-gauge Franseen needle. RESULTS: Specimens suitable for histological evaluation were obtained from 19 of the 20 patients (95%), and the median total tissue area was 11.9 mm2. The histological diagnosis rate of AIP was 65% (95% CI: 43.2%-82%). Adverse events were observed in three patients (15%), and a switch to 22-gauge needles occurred during transduodenal puncture in two patients. Compared to those punctured with 22-gauge needles, patients punctured with 19-gauge needles had greater prevalence of each characteristic feature of lymphoplasmacytic sclerosing pancreatitis, but the difference was not statistically significant. CONCLUSIONS: EUS-FNB using a 19-gauge Franseen needle demonstrated favorable performance for the histological diagnosis of AIP and allowed for large tissue samples, potentially facilitating pathological diagnosis. However, during transduodenal puncture, maneuverability is reduced; therefore, the needle may need to be selected according to the puncture site.

Identification of Inhibitors of the Disease-Associated Protein Phosphatase Scp1 Using Antibody Mimetic Molecules.

Protein phosphorylation is a prevalent translational modification, and its dysregulation has been implicated in various diseases, including cancer. Despite its significance, there is a lack of specific inhibitors of the FCP/SCP-type Ser/Thr protein phosphatase Scp1, characterized by high specificity and affinity. In this study, we focused on adnectin, an antibody-mimetic protein, aiming to identify Scp1-specific binding molecules with a broad binding surface that target the substrate-recognition site of Scp1. Biopanning of Scp1 was performed using an adnectin-presenting phage library with a randomized FG loop. We succeeded in identifying FG-1Adn, which showed high affinity and specificity for Scp1. Ala scanning analysis of the Scp1-binding sequence in relation to the FG-1 peptide revealed that hydrophobic residues, including aromatic amino acids, play important roles in Scp1 recognition. Furthermore, FG-1Adn was found to co-localize with Scp1 in cells, especially on the plasma membrane. In addition, Western blotting analysis showed that FG-1Adn increased the phosphorylation level of the target protein of Scp1 in cells, indicating that FG-1Adn can inhibit the function of Scp1. These results suggest that FG-1Adn can be used as a specific inhibitor of Scp1.

Extensive Hepatic Infarction due to Polycythemia Vera.

Polycythemia vera (PV) is one of the three BCR-ABL1-negative myeloproliferative neoplasms characterized by activating mutations in JAK2, which clinically presents as erythrocytosis and has an increased risk of both thromboembolic events and progression to myelofibrosis and acute myeloid leukemia. Splanchnic vein thrombosis is a rare manifestation of venous thromboembolism involving one or more abdominal vessels and is strongly associated with PV. We herein report a case in which hepatic infarction due to PV was saved by conservative treatment.

Artificial intelligence-based diagnostic imaging system with virtual enteroscopy and virtual unfolded views to evaluate small bowel lesions in Crohn's disease.

Since even subtle mucosal changes may be depicted using virtual endoscopy created by the three-dimensional reconstruction of MDCT images, we developed a novel diagnostic imaging system that integrates and displays virtual enteroscopy, curved planar reconstruction, and a virtual unfolded view, the width of which changes with increases/decreases in the inner luminal diameter. The system is also equipped with artificial intelligence that superimposes and displays depressed areas, generates an automatic small bowel centerline that connects fragmented small bowel regions, and performs electronic cleansing. We retrospectively evaluated the diagnostic performance of this system for small bowel lesions in Crohn's disease, which were divided into two groups: endoscopically-observable and endoscopically-unobservable. Lesion detection rates for stenoses, longitudinal ulcers with a cobblestone appearance, and scars were excellent in both groups. This system, when used in combination with endoscopy, shows slight mucosal changes in areas in which an endoscope cannot reach due to strictures, thereby extending the range of observation of the small bowel. This system is a useful diagnostic modality that has the capacity to assess mucosal healing and provide extraluminal information.

Gastric ectopic pancreas with a pseudocyst.

Ectopic pancreas (EP) is defined as pancreatic tissue that lacks anatomical or vascular connections to the normal pancreas. EP is generally asymptomatic and is detected incidentally during endoscopy. However, due to pseudocyst formation, inflammation, or malignant transformation, it may cause non-specific gastrointestinal symptoms, such as abdominal pain, abdominal discomfort, nausea, vomiting, and bleeding. Pseudocyst formation in EP may result from the retention of exocrine secretions in the absence of connections between the glandular epithelium and gastric lumen. We herein report a case of EP with a pseudocyst associated with epigastric pain. EP with a pseudocyst, although rare, needs to be considered in a differential diagnosis of cystic lesions of the stomach.

Characteristics of microbiomes of the saliva, duodenal bulb, and descending portion of superficial nonampullary duodenal epithelial tumors.

INTRODUCTION: Nonampullary duodenal epithelial tumors are rare, but their prevalence is increasing. Various gastrointestinal cancers have been associated with microbiomes. We evaluated the characteristics of the salivary and duodenal microbiomes of patients with nonampullary duodenal epithelial tumors. METHODS: Saliva and biopsy samples from the duodenal bulb and descending portion were obtained from 15 patients with nonampullary duodenal epithelial tumors and 10 controls. Next-generation sequencing was performed to identify bacteria for comparison. RESULTS: Saliva samples had higher Amplicon Sequence Variants (ASVs) and more observed species than duodenal samples. Saliva samples from patients with nonampullary duodenal epithelial tumor were dominated by Bacteroidetes and Prevotella, whereas Proteobacteria and Neisseria were dominant in the control samples. The relative abundance of bacteria was higher in patients with nonampullary duodenal epithelial tumors. Most bacteria were classified as bacteria of oral origin. Oribacterium and Stomatobaculum were significantly higher in the saliva, duodenal bulb, and descending portion of patients with nonampullary duodenal epithelial tumors. CONCLUSION: Patients with nonampullary duodenal epithelial tumors had different salivary and duodenal microbiomes than controls. Bacteria types differed between groups at each site, and most bacteria of oral origin were more abundant in patients with nonampullary duodenal epithelial tumors.

Clinical outcomes of the over-the-scope clip closure after duodenal endoscopic submucosal dissection: A multicenter retrospective study.

BACKGROUND AND AIM: Prophylactic closure with the over-the-scope clip (OTSC) after endoscopic submucosal dissection (ESD) of superficial non-ampullary duodenal epithelial tumors (SNADETs) has been reported to reduce postoperative adverse events (AEs). However, there are few evidences regarding AEs-associated factors and long-term outcomes of OTSCs. METHODS: From January 2011 to December 2020, 139 consecutive patients with SNADETs who underwent ESD followed by OTSC closure in five institutions were extracted in this retrospective study. The primary endpoint was the rate of postoperative AEs after prophylactic OTSC closure. The secondary endpoints were the complete closure rate, residual rate, and long-term AEs associated with residual OTSCs. RESULTS: The rate of complete closure of the mucosal defect was 97.3% (142) in 146 SNADETs, which were completely resected by ESD. Postoperative AEs, including delayed bleeding, delayed perforation, and localized peritonitis, occurred in 6.2%, 3.4%, and 2.1% of patients, respectively; however, all of the cases improved without surgical treatment. In the multivariate logistic regression analysis, the use of two or more OTSCs was a significant independent risk factor for postoperative AEs (odds ratio, 2.94; 95% confidence interval, 1.02-8.46; P = 0.046). The residual OTSC rate was 46.4% at 1 year postoperatively, and long-term AEs included duodenal erosions and ulcers associated with residual OTSCs. CONCLUSIONS: Prophylactic closure with OTSCs after duodenal ESD can provide acceptable short-and long-term outcomes for preventing postoperative AEs. However, multiple OTSCs were the independent risk factors of postoperative AEs due to the gaps between and near the OTSCs.

Computational fluid dynamics for predicting the growth of small unruptured cerebral aneurysms.

OBJECTIVE: Larger cerebral aneurysms are more likely to enlarge, but even small aneurysms can grow. The aim of this study was to investigate the hemodynamic characteristics regarding the growth of small aneurysms using computational fluid dynamics (CFD). METHODS: The authors analyzed 185 patients with 215 unruptured cerebral aneurysms with a maximum diameter of 3-5 mm, registered in a multicenter prospective observational study of unruptured aneurysms (Systematic Multicenter Study of Unruptured Cerebral Aneurysms Based on Rheological Technique at Mie) from January 2013 to February 2022. Based on findings on repeated images, aneurysms were divided into a stable group (182 aneurysms) and a growth group (33 aneurysms). The authors developed the high shear concentration ratio (HSCR), in which high wall shear stress (HWSS) was defined as a value of 110% of the time-averaged wall shear stress of the dome. High shear area (HSA) was defined as the area with values above HWSS, and the ratio of the HSA to the surface area of the dome was defined as the HSA ratio (HSAR). They also created the flow concentration ratio (FCR) to measure the concentration of the inflow jet. Multivariate logistic regression analysis was performed to determine morphological variables and hemodynamic parameters that independently characterized the risk of growth. RESULTS: The growth group had a significantly higher projection ratio (0.74 vs 0.67, p = 0.04) and volume-to-ostium area ratio (1.72 vs 1.44, p = 0.02). Regarding the hemodynamic parameters, the growth group had significantly higher HSCR (6.39 vs 4.98, p < 0.001), lower HSAR (0.28 vs 0.33, p < 0.001), and lower FCR (0.61 vs 0.67, p = 0.005). In multivariate analyses, higher HSCR was significantly associated with growth (OR 0.81, 95% CI 7.06 e-1 to 9.36 e-1; p = 0.004). CONCLUSIONS: HSCR may be a useful hemodynamic parameter to predict the growth of small unruptured cerebral aneurysms.

Risk factors for rebleeding in gastroduodenal ulcers.

BACKGROUND: Rebleeding after hemostasis of the gastroduodenal ulcer (GDU) is one of the indicators associated with death among GDU patients. However, there are few studies on risk score that contribute to rebleeding after endoscopic hemostasis of bleeding peptic ulcers. AIMS: The aim of this study was to identify factors associated with rebleeding, including patient factors, after endoscopic hemostasis of bleeding gastroduodenal ulcers and to stratify the risk of rebleeding. METHODS: We retrospectively enrolled 587 consecutive patients who were treated for Forrest Ia to IIa bleeding gastroduodenal ulcers with endoscopic hemostasis at three institutions. Risk factors associated with rebleeding were assessed using univariate and multivariate logistic regression analyses. The Rebleeding Nagoya University (Rebleeding-N) scoring system was developed based on the extracted factors. The Rebleeding-N score was internally validated using bootstrap resampling methods. RESULTS: Sixty-four patients (11%) had rebleeding after hemostasis of gastroduodenal ulcers. Multivariate logistic regression analysis revealed four independent rebleeding risk factors: blood transfusion, albumin <2.5, duodenal ulcer, and diameter of the exposed vessel ≧2 mm. Patients with 4 risk factors in the Rebleeding-N score had a 54% rebleeding rate, and patients with 3 risk factors had 44% and 25% rebleeding rates. In the internal validation, the mean area under the curve of the Rebleeding-N score was 0.830 (95% CI = 0.786-0.870). CONCLUSIONS: Rebleeding after clip hemostasis of bleeding gastroduodenal ulcers was associated with blood transfusion, albumin <2.5, diameter of the exposed vessel ≧2 mm, and duodenal ulcer. The Rebleeding-N score was able to stratify the risk of rebleeding.

Effects of 1-kestose on microbiome changes caused by vonoprazan: a randomized, double-blind, placebo-controlled pilot study.

BACKGROUND AND AIM: Potassium-competitive acid blockers more strongly suppress the gastric acid barrier than proton pump inhibitors and cause dysbiosis. However, preventive measures in this regard have not been established. We aimed to evaluate whether 1-kestose, a known prebiotic, was effective at alleviating dysbiosis caused by potassium-competitive acid blockers. METHODS: Patients scheduled to undergo endoscopic resection for superficial gastroduodenal tumors were enrolled and randomized 1:1 to receive either 1-kestose or placebo. All patients were started on potassium-competitive acid blocker (vonoprazan 20 mg/day) and took 1-kestose 10 g/day or placebo (maltose) 5 g/day for 8 weeks. The primary outcome was the effect of 1-kestose on potassium-competitive acid blocker-induced alterations in the microbiome. The fecal microbiome was analyzed before and after potassium-competitive acid blocker treatment via MiSeq (16S rRNA gene V3-V4 region). RESULTS: Forty patients were enrolled, and 16 in each group were analyzed. In the placebo group, the Simpson index, an alpha diversity, was significantly decreased and relative abundance of Streptococcus was significantly increased by 1.9-fold. In the kestose group, the Simpson index did not change significantly and relative abundance of Streptococcus increased 1.3-fold, but this was not a significant change. In both groups, no adverse events occurred, ulcers were well healed, and pretreatment and posttreatment short-chain fatty acid levels did not differ. CONCLUSIONS: The potassium-competitive acid blocker caused dysbiosis in the placebo group; this effect was prevented by 1-kestose. Thus, 1-kestose may be useful in dysbiosis treatment.

Endoscopic submucosal dissection using a novel thin-therapeutic endoscope for superficial esophageal squamous cell carcinoma with severe stricture at the pharyngoesophageal junction.

When performing endoscopic submucosal dissection (ESD) beyond stenoses, there have only been two choices: balloon dilation until a conventional therapeutic endoscope passes through or the use of an ultrathin endoscope. However, balloon dilation has a risk of perforation and an ultrathin endoscope limits the devices that may be used. The novel thin-therapeutic endoscope has an outer diameter of 7.9 mm and instrument channel diameter of 3.2 mm; therefore, there are no restrictions on the ESD device that may be used, and the procedure may be performed in the same manner as regular ESD. We herein report a case in which the thin-therapeutic endoscope was useful for esophageal ESD beyond a stenosis.

Suturing of a mucosal defect after gastric endoscopic submucosal dissection using a combination of an anchor pronged clip and conventional clips.

Suturing of a mucosal defect after gastric endoscopic submucosal dissection (ESD) reduces the incidence of adverse events and shortens hospitalization. However, post-ESD mucosal defects are circular, large, and with a thick mucosal layer, which are difficult to suture using conventional clips alone. The MANTIS Clip (Boston Scientific Japan, Tokyo, Japan) is a reopenable, rotatable through-the-scope clip designed for large defect closure. It uses anchor prongs to securely grasp wound edges. The initial use of the MANTIS Clip significantly reduces mucosal defects, which then allows for easy suturing with conventional clips. We herein report a case in which the MANTIS Clip was useful for suturing a mucosal defect after gastric ESD.

Monoclonal Antibody Against Mature Interleukin-18 Ameliorates Colitis in Mice and Improves Epithelial Barrier Function.

BACKGROUND: Antitumor necrosis factor (TNF)-α antibodies have improved the outcome of inflammatory bowel disease (IBD); but half of patients remain unresponsive to treatment. Interleukin-18 (IL-18) gene polymorphism is associated with resistance to anti-TNF-α antibodies, but therapies targeting IL-18 have not been clinically applied. Only the mature protein is biologically active, and we aimed to investigate whether specific inhibition of mature IL-18 using a monoclonal antibody (mAb) against a neoepitope of caspase-cleaved mature IL-18 could be an innovative treatment for IBD. METHODS: The expression of precursor and mature IL-18 in patients with UC was examined. Colitis was induced in C57/BL6 mice by administering dextran sulfate sodium (DSS), followed by injection with anti-IL-18 neoepitope mAb. Colon tissues were collected and subjected to histological analysis, immunohistochemistry, immunoblotting, and quantitative polymerase chain reaction. Colon epithelial permeability and microbiota composition were analyzed. RESULTS: Mature IL-18 expression was elevated in colon tissues of patients with active ulcerative colitis. Administration of anti-IL-18 neoepitope mAb ameliorated acute and chronic DSS-induced colitis; reduced interferon-γ, TNF-α, and chemokine (CXC motif) ligand-2 production and epithelial cell permeability; promoted goblet cell function; and altered the intestinal microbiome composition. The suppressive effect of anti-IL-18 neoepitope mAb was superior to that of anti-whole IL-18 mAb. Furthermore, combination therapy with anti-TNF-α Ab suppressed acute and chronic colitis additively by suppressing cytokine expressions and reducing cell permeability by upregulating claudin1 and occludin expression. CONCLUSIONS: Anti-IL-18 neoepitope mAb ameliorates acute and chronic colitis, suggesting that this mAb will be an innovative therapeutic option for IBD.

We investigate a novel monoclonal antibody that specifically recognizes a neoepitope of caspase-cleaved IL-18 and alleviates dextran sulfate sodium-induced colitis by suppressing the secretion of inflammatory cytokines, improving intestinal epithelial permeability, promoting goblet cell function, and regulating intestinal microbiota.

Current status of and future issues related to endoscopic papillectomy.

Endoscopic papillectomy is widely performed to treat duodenal papillary tumors, particularly at high-volume centers. It is indicated for adenomas without intraductal extension of the bile or pancreatic ducts. However, despite numerous reports of carcinomas that expand the indications to include well-differentiated adenocarcinomas that do not invade the sphincter of Oddi, the low agreement between biopsy and final pathological diagnosis, as well as the current inability of imaging modalities to diagnose sphincter of Oddi invasion, makes it difficult to consider expanding indications. Although complications can be prevented by certain methods, such as pancreatic duct stenting, and the frequency of severe complications has decreased, the safety of the procedure remains unconfirmed. In the future, this technology is expected to progress and enable wider applications, including those in tumors with extensive horizontal spread and those with intraductal extension of the bile and pancreatic ducts. Such technology may also improve the safety and accuracy of diagnosis.

Low Expectancy of Conversion Surgery with R0 Resection in Patients with CEA > 5.0 ng/mL at the Initial RECIST Evaluation for Metastatic Gastric Cancer.

This retrospective study examined early the predictive factors for successful conversion surgery (CS) with R0 resection in patients with metastatic gastric cancer (MGC) who underwent systemic chemotherapy. This study included 204 patients diagnosed with metastatic gastric adenocarcinoma, who received chemotherapy between 2009 and 2019. Of these patients, 31 (15%) underwent CS with R0 resection. The incidence of CS with R0 resection was not affected by the volume of metastatic lesions or the presence of peritoneal metastasis. The overall survival time of the CS with R0 resection group was significantly longer than that of the non-CS group (hazard ratio, 0.12; 95% confidence interval, 0.07-0.23; p < 0.0001), with a 5 year overall survival rate of 50.2%. Multivariate analysis of 150 patients, excluding those with disease progression until the initial Response Evaluation Criteria in Solid Tumors (RECIST) evaluation, showed that carcinoembryonic antigen > 5.0 ng/mL at the initial RECIST evaluation was an independent, significant, and unfavorable predictor of CS with R0 resection (odds ratio, 0.21; p = 0.0108), whereas systemic chemotherapy with trastuzumab for HER2-positive cancer was a favorable factor (odds ratio, 4.20; p = 0.0119). Monitoring serum carcinoembryonic antigen levels during chemotherapy may be a useful predictor of the CS implementation in patients with MGC.

Real-World Effectiveness and Risk Factors for Discontinuation of Ustekinumab in Ulcerative Colitis.

Introduction: Ustekinumab (UST) has been approved for the treatment of moderate-to-severe ulcerative colitis (UC). Real-world data showing the effectiveness and safety of UST are necessary to confirm the results of clinical trials for applicability in daily clinical practice. Although some studies have reported real-world evidence of UST, only few studies have confirmed its effectiveness in the real world. The aim of this study was to assess the short- and long-term effectiveness, durability, safety, and risk factors for discontinuation of UST in UC in clinical practice. Methods: This was a retrospective, single-center, observational study. From March 2020 to January 2023, all consecutive patients with active UC who were treated with UST at Nagoya University Hospital were included. The primary outcome was the clinical remission rate at weeks 2-8 and weeks 24-48. The secondary outcomes included clinical response, persistence of UST therapy, endoscopic changes during follow-up, risk factors for UST discontinuation, and occurrence of any adverse events. The clinical effectiveness was evaluated using the Lichtiger score. Results: A total of 31 patients were included in this study. The clinical remission rates were 9.7%, 29.0%, 54.8%, and 64.5% at weeks 2, 8, 24, and 48, respectively. Twelve (38.7%) patients discontinued UST during the follow-up period. The probability of continuing UST was 93.5%, 80.6%, 77%, and 70% at weeks 2, 8, 24, and 48, respectively. The major reason for discontinuation of UST was primary failure (75.0%). A high baseline C-reactive protein (CRP) level was a significant risk factor for the discontinuation of UST. No adverse events were observed in this study. Conclusion: UST is effective for patients with UC. High CRP levels were identified as a risk factor for UST discontinuation. The findings of this study would help clinicians to select appropriate treatment options for patients with UC by identifying the risk factors for treatment discontinuation.

Hemodynamic differences of posterior communicating artery aneurysms between adult and fetal types of posterior cerebral artery.

BACKGROUND: The recanalization of posterior communicating artery (PCoA) aneurysms after endovascular treatment has been analyzed by various factors. However, the differences between adult and fetal types of posterior cerebral artery (PCA) have not been fully investigated. The main aim of this study was to investigate hemodynamic differences of PCoA aneurysms between adult and fetal types using computational fluid dynamics (CFD). METHODS: Fifty-five PCoA aneurysms were evaluated by 3D CT angiography and divided into unruptured aneurysms with adult-type or fetal-type PCAs (19 cases, UA group; 9 cases, UF group) and ruptured aneurysms with adult-type or fetal-type PCAs (17 cases, RA group; 10 cases, RF group). These native aneurysms were analyzed by CFD regarding morphological and hemodynamic characteristics. To evaluate simulated endovascular treatment of aneurysms, CFD was performed using porous media modeling. RESULTS: Morphologically, the RA group had significantly smaller parent artery diameter (2.91 mm vs. 3.49 mm, p=0.005) and higher size ratio (2.54 vs. 1.78, p=0.023) than the RF group. CFD revealed that the UA group had significantly lower oscillatory shear index (OSI) (0.0032 vs. 0.0078, p=0.004) than the UF group and that the RA group had lower WSS (3.09 vs. 11.10, p=0.001) and higher OSI (0.014 vs. 0.006, p=0.031) than the RF group, while the RF group presented significantly higher intra-aneurysmal flow velocity (0.19 m/s vs. 0.061 m/s, p=0.002) than the RA group. Porous media modeling of simulated treatment revealed higher residual flow volume in the fetal-type groups. CONCLUSIONS: These results suggested that PCoA aneurysms with fetal-type PCAs had different morphological features and hemodynamic characteristics compared with those with adult-type PCAs, leading to high risks of recanalization.

Clinical characteristics of Dieulafoy's lesion in the small bowel diagnosed and treated by double-balloon endoscopy.

BACKGROUND: Obscure gastrointestinal bleeding refers to bleeding for which the source cannot be ascertained even through balloon-assisted endoscopy. In certain instances, Dieulafoy's lesion in the small bowel is presumed to be the underlying cause. AIM: This retrospective study aimed to elucidate the clinical characteristics of Dieulafoy's lesion in the small bowel as diagnosed via double-balloon endoscopy while also exploring the feasibility of predicting bleeding from Dieulafoy's lesion prior to endoscopy in cases of obscure gastrointestinal bleeding. METHODS: A comprehensive analysis of our database was conducted, identifying 38 patients who received a diagnosis of Dieulafoy's lesion and subsequently underwent treatment via double-balloon endoscopy. The clinical background, diagnosis, and treatment details of patients with Dieulafoy's lesion were carefully examined. RESULTS: The median age of the 38 patients was 72 years, and 50% of the patients were male. A total of 26 (68%) patients exhibited a high comorbidity index. The upper jejunum and lower ileum were the most frequently reported locations for the occurrence of Dieulafoy's lesion in the small bowel. The detected Dieulafoy's lesions exhibited active bleeding (n = 33) and an exposed vessel with plaque on the surface (n = 5). Rebleeding after endoscopic treatment occurred in 8 patients (21%, median period: 7 days, range: 1-366 days). We conducted an analysis to determine the definitive nature of the initial double-balloon endoscopy diagnosis. Multivariate analysis revealed that hematochezia of ≥ 2 episodes constituted the independent factor associated with ≥ 2 double-balloon endoscopy diagnoses. Additionally, we explored factors associated with rebleeding following endoscopic treatment. Although the number of hemoclips utilized displayed a likely association, multivariate analysis did not identify any independent factor associated with rebleeding. CONCLUSION: If a patient encounters multiple instances of hematochezia, promptly scheduling balloon-assisted endoscopy, equipped with optional instruments without delay is advised, after standard endoscopic evaluation with esophagogastroduodenoscopy and colonoscopy is unrevealing.