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Abstract Alterations in KRAS, CDKN2A (p16), TP53, and SMAD4 genes have been major drivers of pancreatic carcinogenesis. The clinical course of patients with pancreatic cancer in relation to these driver alterations has not been fully characterised in large populations. We hypothesised that pancreatic carcinomas with different combinations of KRAS mutation and aberrant expression of CDKN2A, p53, and SMAD4 might show distinctive recurrence patterns and post‐operative survival outcomes. To test this hypothesis, we utilised a multi‐institutional cohort of 1,146 resected pancreatic carcinomas and assessed KRAS mutations by droplet digital polymerase chain reaction and CDKN2A, p53, and SMAD4 expression by immunohistochemistry. Multivariable hazard ratios (HRs) and 95% confidence intervals (CIs) for disease‐free survival (DFS) and overall survival (OS) were computed according to each molecular alteration and the number of altered genes using the Cox regression models. Multivariable competing risks regression analyses were conducted to assess the associations of the number of altered genes with specific patterns of recurrence. Loss of SMAD4 expression was associated with short DFS (multivariable HR, 1.24; 95% CI, 1.09–1.43) and OS times (multivariable HR, 1.27; 95% CI, 1.10–1.46). Compared to cases with 0–2 altered genes, cases with three and four altered genes had multivariable HRs for OS of 1.28 (95% CI, 1.09–1.51) and 1.47 (95% CI, 1.22–1.78), respectively (ptrend

Abstract Objectives Hepaticojejunostomy anastomotic stricture (HJAS) is a serious adverse event of pancreaticoduodenectomy. Preoperative biliary drainage with a self‐expandable metal stent (SEMS) is often performed before pancreaticoduodenectomy. The purpose of this study is to evaluate the risk factors and impact of preoperative SEMS placement on developing benign HJAS after pancreaticoduodenectomy. Methods We retrospectively analyzed consecutive patients who underwent pancreatoduodenectomy at our institution between July 2014 and June 2020. Risk factors for benign HJAS were identified using univariate and multivariate logistic regression analysis. We also compared outcomes of preoperative biliary drainage using SEMS and non‐SEMS. Results Of the 626 included patients, benign HJAS occurred in 36 patients (5.8%). The median follow‐up time was 36.7 months (interquartile range, 25.4–57.4 months). Multivariate logistic regression analysis revealed that lack of preoperative biliary drainage, preoperative bile duct diameter

Abstract Background 10‐mm self‐expandable metal stents (SEMSs) are commonly used for preoperative biliary drainage in pancreatic cancer. However, smaller diameter SEMSs have attracted attention with the attempt to reduce stent‐related adverse events (AEs). Methods We retrospectively analyzed consecutive borderline resectable pancreatic cancer patients who underwent neoadjuvant therapy and fully covered SEMS (FCSEMS) placement from April 2015 to May 2023. The primary outcome was stent‐related non‐event rate (NER), which was defined as the rate of completion of surgery without developing any preoperative events (recurrent biliary obstruction [RBO] or stent‐related AEs). Secondary outcomes included stent‐related AEs, causes of RBO, and cumulative incidence of RBO. Risk factors for pancreatitis, RBO, and stent migration were also examined. Results A total of 76 patients were included (6‐mm group: 23; 10‐mm group: 53). Stent‐related NER (57% vs. 64%, p = 0.610), stent‐related AEs (4% vs. 15%, p = 0.263), overall RBO rates (39% vs. 23%, p = 0.168), cumulative incidence of RBO (hazard ratio, 2.24; 95% confidence interval, 0.95–5.25; p = 0.065) were not significantly different between the two groups. Tumor involvement of the pancreatic duct was identified as a risk‐reducing factor for pancreatitis, while an FCSEMS diameter of 6 mm was not identified as a risk factor for RBO and stent migration. Conclusions Stent‐related NER was not significantly affected by FCSEMS diameter. Further studies are needed to confirm the usefulness of 6‐mm diameter FCSEMS for preoperative biliary drainage in patients with borderline resectable pancreatic cancer.

Abstract We report a case of ruptured cystic artery pseudoaneurysm after self‐expandable metal stent placement for malignant biliary obstruction. A 78‐year‐old woman on palliative care after chemotherapy for unresectable pancreatic head cancer presented with obstructive jaundice. Imaging revealed a dilated common bile duct and an enlarged gallbladder with cystic wall thickening. Endoscopic retrograde cholangiopancreatography was performed and a fully‐covered self‐expandable metal stent was placed in the bile duct, leading to resolution of jaundice. She presented with hematochezia 7 days later. Contrast‐enhanced computed tomography revealed a cystic artery pseudoaneurysm with extravasation of contrast into a blood‐filled gallbladder. Hemostasis was achieved after emergent transcatheter arterial embolization. Rupture of cystic artery pseudoaneurysm should be raised as a differential diagnosis for hemobilia after self‐expandable metal stent placement, particularly in cases accompanied by inflamed gallbladders.

Abstract Objectives Duckbill‐type metal stent (DMS) was the first laser‐cut biliary metal stent with an anti‐reflux valve. Removal of DMS is believed to be difficult and relevant reports are scarce. This study aims to investigate the feasibility of DMS removal. Methods We retrospectively analyzed patients who underwent DMS removal between June 2019 and March 2022 to evaluate success rates and factors affecting outcomes. In addition, six different methods of DMS removal were reproduced in vitro, varying removal devices, angle of applied force, and grasped location. Extraction resistance, the distance of forceps stroke, and stent length after removal were compared. Results Forty patients were enrolled, and DMS removal was successful in 31 cases (78%). No adverse events were observed. Tumor ingrowth was evident in 78% (7/9) of failed cases. Patients receiving biliary metal stents for the first time (naïve cases), long indwelling time, longer stent, and stent tearing during removal were associated with unsuccessful stent removal. In the in vitro study, a larger force was required to remove the stent at an extraction angle of 120° than at 0°. Among cases in which force was applied at 120°, the load tended to be lower when rat‐tooth forceps were applied horizontally across the stent. Conclusions Stent removal was possible in a majority of cases. Deployment of additional stents inside DMS may be preferable to forceful removal in the presence of factors associated with difficult stent removals, such as tumor ingrowth, naïve cases, longer stents, long indwelling time, and stent tearing during removal.

Abstract Background The usefulness of duckbill‐type anti‐reflux metal stent (DMS) in self‐expandable metal stent‐naïve pancreatic cancer (PC) patients has not been well‐studied. This study aimed to evaluate the efficacy and safety of DMS in such patients. Methods We analyzed consecutive patients with unresectable PC who received a covered metal stent (CMS) as the initial self‐expandable metal stent at our institution. Technical success, functional success, causes of recurrent biliary obstruction (RBO), time to RBO (TRBO), adverse events (AEs), and reintervention rates were compared between DMS and conventional CMS (c‐CMS). Results A total of 69 patients were included (DMS: 28, c‐CMS: 41). Technical success, functional success, and AEs were similar between groups. Tumor ingrowth was more common in the DMS group (18% vs. 0%, p = 0.009), while non‐occlusion cholangitis tended to be more common in the c‐CMS group (0% vs. 15%, p = 0.074). Median time to RBO was similar between groups (276 vs. 273 days, p = 0.915). The anti‐reflux valve of DMS was found torn in 56% of patients. Endoscopic reintervention was successful in all cases, despite failed stent removal in 88% of patients in the DMS group. Conclusions DMS was not associated with longer time to RBO compared to c‐CMS in self‐expandable metal stent‐naïve patients.