Analysis of the variation in learning curves for achieving competency in convex EUS training: a prospective cohort study using a standardized assessment tool.

BACKGROUND AND AIMS: The need for mastering standard imaging techniques for convex EUS in the biliopancreatic regions has been increasing; however, large variations in the aptitude for achieving EUS competency hinder expert development. Therefore, we investigated the factors influencing the achievement of expert competency in EUS using a new assessment tool for multiple imaging items. METHODS: Between January 2018 and February 2022, 3277 consecutive EUS procedures conducted by 5 beginners (EUS procedures <250), 7 intermediate trainees (250-749), and 2 experts (≥750) were prospectively evaluated. Immediately after each EUS procedure, the success or failure of imaging for each item was recorded using a newly developed EUS assessment tool that requires 17 items to be photographed. After correcting for missing values using multiple imputation, learning curves of EUS scores were created, and a competency was set based on expert scores. Finally, a comparative analysis between high and low performers was performed to extract factors influencing EUS scores. RESULTS: Although 3 of 7 intermediates (43%; mean, 317 cases) achieved competency, none of the beginners achieved competency. During a comparative analysis, although no significant difference in the number of EUS procedures performed was observed between the high and low performers, the former had significantly higher scores in the written test (theoretical knowledge). CONCLUSIONS: Our results showed that theoretical knowledge, rather than the number of EUS cases, may be a possible influencing factor for distinguishing high and low performers after treating 250 cases. (Clinical trial registration number: UMIN 000043271.).

Potential significance of uncovered self-expandable metal stents for distal malignant biliary obstruction: A propensity score-adjusted competing risk regression analysis.

Objectives: Selection criteria for self-expandable metal stents (SEMSs) with or without cover during palliative treatment of distal malignant biliary obstruction (DMBO) remain unclear. We evaluated factors associated with time to recurrent biliary obstruction (TRBO) in fully covered SEMSs (FCSEMSs) and uncovered SEMSs (UCSEMSs). Methods: We retrospectively analyzed consecutive patients with DMBO who received a SEMS. TRBO was determined using the Kaplan-Meier analysis, and complications were compared between the FCSEMS and UCSEMS groups. After TRBO-associated factors were extracted using multivariate competing-risks regression (CRR), propensity score-adjusted CRRs were performed to verify their robustness. Results: There were 180 patients (66 FCSEMSs and 114 UCSEMSs) enrolled in this study. There was no significant difference between median TRBO in the FCSEMS and UCSEMS groups (275 vs. 255 days, p = 0.67). Complications were more frequent in the FCSEMS than UCSEMS group (21.2% vs. 8.8%; p = 0.023). Multivariate CRR for TRBO-associated factors revealed that "pancreatic ductal carcinoma (PDAC) treated with UCSEMS" was the only independent predictor of TRBO (p = 0.03). Similarly, the propensity score-adjusted CRRs showed no significant difference in TRBO in "FCSEMS" vs "UCSEMS" (p = 0.96); however, there was a significant difference in "PDAC using UCSEMS" vs "other" (p = 0.043). In the palliative care group including any DMBO without chemotherapy, the first quartile of the TRBO of UCSEMS was 100 days. Conclusions: UCSEMSs are a possible option for both patients with DMBO arising from PDAC and for patients with any DMBO receiving palliative care who should avoid SEMS-related complications.

Diagnostic Dilemma of Biliopancreatic Contrast-Enhanced Harmonic Endoscopic Ultrasonography.

Background: The utility of contrast-enhanced harmonic endoscopic ultrasonography (CH-EUS) alone in the biliopancreatic region appears to be limited because it is highly dependent on the experience and skill of the endoscopist. Therefore, the present study aimed to validate the efficacy of CH-EUS in clinical practice. Methods: Between January 2018 and March 2019, 301 consecutive patients who underwent CH-EUS were prospectively enrolled in this study. The diagnostic performance of CH-EUS was compared with that of dynamic computed tomography (CT), magnetic resonance imaging (MRI), and all combinations (i.e., CH-EUS, dynamic CT, and MRI) using a Bonferroni correction. A multiple logistic regression analysis was performed to extract each disease that allowed the CH-EUS diagnosis to be consistent with the final diagnosis. Results: In multiple comparisons of diagnostic performance, no significant differences were observed among dynamic CT, MRI, and CH-EUS (p = 1.00), but the diagnostic performance was significantly higher when all modalities were combined (p < 0.001). Moreover, only intraductal papillary mucinous neoplasm comprising adenoma or carcinoma (IPMN, n = 161) showed significance with respect to the agreement with the final diagnosis (p = 0.006). Conclusions: Our results showed that CH-EUS-based diagnosis of IPMN may be possible in clinical practice. On the contrary, to accurately diagnose biliopancreatic diseases other than IPMN, comprehensive diagnosis using multiple modalities may be necessary, rather than relying on CH-EUS alone.

Tardive peritonitis after the endoscopic ultrasound-guided hepaticogastorostomy: A case report.

Endoscopic ultrasound-guided biliary drainage (EUS-BD) has become popular as a new drainage technique for malignant biliary strictures. Although EUS-BD has been reported to show high technical and clinical success rates, the rate of adverse events is 15%. In particular, peritonitis, which is generally caused by bile leakage from the aspiration side during the procedure and occurs within a few days after EUS-BD, needs to be considered as it can be fatal. In the present case, a jaundiced patient presented with unresectable pancreatic adenocarcinoma. Due to duodenal invasion, we performed EUS-guided hepaticogastrostomy for biliary drainage. After the procedure, jaundice improved, and abdominal computed tomography (CT) showed only a small amount of air in the intrahepatic bile duct. However, 7 days after the procedure, the patient developed fever, and clinical findings indicated peritonitis. Abdominal CT showed food in the stomach accompanied by the appearance of perihepatic free air, with increased air in the intrahepatic bile duct. The duodenal stent insertion settled the peritonitis and improved the perihepatic free air and the air in the intrahepatic bile duct through the discharge of food from the stomach. To date, no case of tardive peritonitis associated with air leakage after EUS-BD has been reported. We noted that even if there was no evidence of bile leakage after EUS-BD, the possibility of tardive peritonitis due to gradual air leakage from the stent implantation side of the stomach should be considered, and careful follow-up is needed.

Endoscopic ultrasound-guided fine-needle biopsy histology with a 22-gauge Franseen needle and fine-needle aspiration liquid-based cytology with a conventional 25-gauge needle provide comparable diagnostic accuracy in solid pancreatic lesions.

BACKGROUND AND AIM: Fine-needle biopsy (FNB) needles obtain more core samples and support the shift from cytologic to histologic evaluation; however, recent studies have proposed a superior diagnostic potential for liquid-based cytology (LBC). This study compared the diagnostic ability of endoscopic ultrasound (EUS)-guided FNB histology with a 22-gauge Franseen needle (22G-FNB-H) and fine-needle aspiration (FNA) LBC with a conventional 25-gauge needle (25G-FNA-LBC). METHODS: We analyzed 46 patients who underwent both 22G-FNB-H and 25G-FNA-LBC in the same lesion during the same endoscopic procedure. This study evaluated the diagnostic ability of each needle, diagnostic concordance between needles, and incremental diagnostic effect of both needles compared to using each needle alone. RESULTS: The agreement rate for malignancy between both techniques was 93.5% (kappa value = 0.82). There was no significant difference in the diagnostic ability of both methods. 22G-FNB-H and 25G-FNA-LBC provided an incremental diagnostic accuracy in two (4.3%) cases and one (2.2%) case, respectively. CONCLUSION: Our study demonstrated that the diagnostic accuracy of 25G-FNA-LBC and 22G-FNA-H for solid pancreatic lesions were comparable. A conventional 25-gauge needle that punctures lesions with ease can be used in difficult cases and according to the skill of the endoscopist.

The milestone for preventing post-ERCP pancreatitis using novel simplified predictive scoring system: a propensity score analysis.

BACKGROUND: Post-ERCP pancreatitis (PEP) with trans-papillary approach remains a major issue, and the multi-factorial etiology can lead to the development of unpredictable PEP. Therefore, the early identification of PEP is highly desirable to assist with the health cost containment, the reduction in unnecessary admissions, earlier appropriate primary care, and intensive care for preventing progression of severe pancreatitis. This study aimed to establish a simplified predictive scoring system for PEP. METHODS: Between January 1, 2012, and December 31, 2019, 3362 consecutive trans-papillary ERCP procedures were retrospectively analyzed. Significant risk factors were extracted by univariate, multivariate, and propensity score analyses, and the probability of PEP in the combinations of each factor were quantified using propensity score analysis. The results were internally validated using bootstrapping resampling. RESULTS: In the scoring system with four stratifications using combinations of only five extracted risk factors, the very high-risk group showed 28.79% (95% confidence interval [CI], 18.30%-41.25%; P < 0.001) in the predicted incidence rate of PEP, and 9.09% (95% CI, 3.41%-18.74%; P < 0.001) in that of severe PEP; although the adjusted prevalence revealed 3.74% in PEP and 0.90% in severe PEP, respectively. The prediction model had an area under the curve of 0.86 (95% CI, 0.82-0.89) and the optimism-corrected model as an internal validation had an area under the curve of 0.81 (95% CI, 0.77-0.86). CONCLUSIONS: We established and validated a simplified predictive scoring system for PEP using five risk factors immediately after ERCP to assist with the early identification of PEP.

Blood group O is a risk factor for delayed post-polypectomy bleeding.

BACKGROUND: Blood group O of ABO blood group system is considered as a risk factor for various bleeding events, but the relationship with endoscopic treatment-associated bleeding has yet to be investigated. This study aimed to evaluate whether blood group O is associated with delayed bleeding after colorectal endoscopic resection. METHODS: This was a retrospective observational study based on medical records at four university hospitals in Japan. We reviewed the records for consecutive patients who underwent colorectal endoscopic resection from January 2014 through December 2017. The primary outcome was the incidence of delayed bleeding, defined as hematochezia or melena, requiring endoscopy, transfusion, or any hemostatic intervention up to 28 days after endoscopic resection. Multivariate logistic regression analysis was performed to adjust the impact of blood group O on the delayed bleeding. RESULTS: Among 10,253 consecutive patients who underwent colorectal endoscopic resection during the study period, 8625 patients met the criteria. In total, delayed bleeding occurred in 255 patients (2.96%). The O group had significantly more bleeding events compared with the non-O group (A, B, and AB) (relative risk, 1.62 [95% confidence interval, 1.24-2.10]; P < 0.001). In multivariate logistic regression analysis, blood group O remained an independent risk factor for the bleeding (adjusted odds ratio, 1.60 [95% confidence interval, 1.18-2.17]; P = 0.002). CONCLUSIONS: Blood group O was associated with an increased risk of delayed bleeding in patients undergoing colorectal endoscopic resection. Preoperative screening for ABO blood group could improve risk assessments.

Best period to replace or change plastic stents with self-expandable metallic stents using multivariate competing risk regression analysis.

In endoscopic biliary drainage (EBD) for various benign and malignant biliary disorders, the appropriate timing to replace or change a plastic stent (PS) with a self-expandable metallic stent (SEMS) remains unclear. This study aimed to define the best period to replace or change a PS with a SEMS. Between January 1, 2012, and December 31, 2018, 1,887 consecutive EBD procedures, including 170 SEMS placements, were retrospectively identified. The period to recurrent biliary obstruction (PRBO) was estimated and compared between the malignant and benign groups and according to each disease using time to event analysis and competing risk analysis. Compared with the benign group, the malignant group had significantly shorter median PRBO with interquartile range (IQR) after PS placement [108 (39 - 270) vs. 613 (191 - 1,329) days, P < 0.001], even on multivariate analysis, with a subdistribution hazard ratio (SHR) of 3.58 (P < 0.001). The shortest PRBO distribution from the first quartile of the non-RBO period was seen in Mirizzi syndrome cases (25 days, P = 0.030, SHR = 3.32) in the benign group and in cases of pancreatic cancer (32 days, P = 0.041, SHR = 2.06); perihilar bile duct cancer (27 days, P = 0.006, SHR = 2.69); and ampullary cancer (22 days, P = 0.001, SHR = 3.78) in the malignant group. Our study supports that stent replacement for the benign group is feasible after 6 months, and the best period to replace or change a PS with a SEMS should be decided on the basis of the underlying disease to prevent RBO.

Antitumor effect of VEGFR2-targeted microbubble destruction with gemcitabine using an endoscopic ultrasound probe: In vivo mouse pancreatic ductal adenocarcinoma model.

BACKGROUND: Ultrasound-targeted microbubble destruction (UTMD) induces cellular inflow of drugs at low intensity, while high intensity eradicates tumor vessels. Since vascular endothelial growth factor receptor 2 (VEGFR2) is highly expressed in pancreatic ductal adenocarcinoma (PDAC), VEGFR2-targeted microbubble (MB) might additionally increase the tissue specificity of drugs and thus improve antitumor effects. In addition, fixing the dual pulse intensity could maximize MB properties. This study evaluated the one-off (experiment 1) and cumulative (experiment 2) treatment effect of UTMD by regulating the dual pulse output applied to PDAC using VEGFR2-targeted MB. METHODS: C57BL/6 mice inoculated with Pan-02 cells were allocated to five groups: VEGFR2-targeted MB+ gemcitabine (GEM), VEGFR2-targeted MB, non-targeted MB+GEM, GEM, and control groups. After injection of GEM or GEM and either VEGFR2-targeted or non-targeted MB, UTMD was applied for several minutes at low intensity followed by high intensity application. In experiment 1, mice were treated by the protocol described above and then euthanized immediately or at the tumor diameter doubling time (TDT). In experiment 2, the same protocol was repeated weekly and mice were euthanized at TDT regardless of protocol completion. Histological analysis by CD31 and VEGFR2 staining provided microvascular density (MVD) and VEGFR2 expression along vessels (VEGFR2v) or intra/peripheral cells (VEGFR2c). RESULTS: In experiment 1, TDT was significantly longer in the VEGFR2-targeted MB+GEM group compared to the non-targeted MB+GEM, GEM, and control groups, while the VEGFR2-targeted MB group showed no statistical significance. MVD and VEGFR2v in the immediate euthanasia was significantly lower in the VEGFR2-targeted MB+GEM and VEGFR2-targeted MB groups than other conditions. In experiment 2, the VEGFR2-targeted MB+GEM group produced significantly longer TDT than the GEM or control groups, whereas the VEGFR2-targeted MB group showed no significant difference. Histology revealed significantly reduced VEGFR2v and VEGFR2c in the VEGFR2-targeted and non-targeted MB+GEM groups, while only VEGFR2v was significantly less in the VEGFR2-targeted MB group. CONCLUSIONS: UTMD-mediated GEM therapy with the dual pulse application using VEGFR2-targeted MB substantially suppresses PDCA growth.

Intra-abdominal pressure during endoscopic full-thickness resection comparing manual and automatic control insufflation: a block-randomized porcine study.

BACKGROUND AND STUDY AIMS: An automatic carbon dioxide (CO2) insufflating system (SPACE) was developed to stabilize intra-lumenal pressure (ILP) during endoscopic interventions. This study investigated whether SPACE could improve the control and monitoring of extra-lumenal intra-abdominal pressure (IAP) after establishing a perforation during endoscopic full-thickness resection (EFTR) of the gastric wall in porcine models. MATERIALS AND METHODS: After first establishing the optimal preset pressure for gastric EFTR in four pigs, we compared IAP dynamics during EFTR between manual insufflation and SPACE using a block-randomized study (n = 10). IAP was percutaneously monitored and plotted on a timeline graph every 5 s. The maximal IAP and the area under the IAP curve exceeding 10 mmHg (AUC≥10 mmHg) were compared between groups, with the agreement between IAP and endolumenally monitored ILP also analyzed for animals in the SPACE group. RESULTS: In the first study, 8 mmHg was identified as the most preferable preset pressure after establishment of the perforation. In the randomized study, the mean maximal IAP in the SPACE group was significantly lower than that in the manual insufflation group (11.0 ± 2.0 mmHg vs. 17.0 ± 3.5 mmHg; P = 0.03). The mean AUC≥10 mmHg was also significantly smaller in the SPACE group. Bland-Altman analysis demonstrated agreement between IAP and ILP within a range of ± 1.0 mmHg. CONCLUSIONS: SPACE could be used to control and safely monitor IAP during gastric EFTR by measuring ILP during perforation of the gastric wall.