Chandrasekhara, Vinay

Background: The optimal self-expandable metallic stent (SEMS) choice for endoscopic drainage of unresectable extrahepatic malignant biliary obstruction (MBO) with endoscopic retrograde cholangiopancreatography (ERCP) remains unclear due to limited randomized controlled trial (RCT) evidence. Prior meta-analyses have relied on observational data, introducing heterogeneity and bias. To overcome these limitations, an RCT-only network meta-analysis (NMA) was performed to evaluate the efficacy and safety of SEMS types. Methods: A literature search was conducted to identify RCTs assessing fully covered SEMS (FCSEMS), partially covered SEMS (PCSEMS), and/or uncovered SEMS (UCSEMS) for ERCP drainage of unresectable extrahepatic MBO. Study outcomes included recurrent biliary obstruction (RBO), specific causes of RBO, overall survival (OS), and adverse events (AEs). A frequentist NMA was performed to estimate hazard ratios (HRs) and incidence rate ratios (IRRs) with their 95% confidence intervals and overall P-scores. Results: Ten RCTs (1,659 patients) were included. There were no significant differences in time to RBO, incidence of any RBO, or OS between stent types. UCSEMS had the lowest rates of stent migration, tumor overgrowth, and sludge occlusion, whereas FCSEMS most effectively prevented tumor ingrowth. AE rates were similar across groups; however, only FCSEMS, but not PCSEMS, had significantly higher rates of acute cholecystitis than UCSEMS in patients with an intact gallbladder. Conclusion: There were no differences in RBO, OS, or AE excluding acute cholecystitis between each SEMS type, although each type has its advantages and disadvantages. FCSEMS was associated with a higher risk of acute cholecystitis, emphasizing careful patient selection, particularly regarding gallbladder status.

Photodynamic priming (PDP), a fallout of photodynamic therapy, transiently modulates the tumor microenvironment (TME), enhances therapeutic susceptibility, and promotes immunogenic cell death through the release of damage-associated molecular patterns (DAMPs). Pancreatic ductal adenocarcinoma (PDAC) remains non-responsive to current therapies with a desmoplastic and immunosuppressive TME that limits drug delivery and blunts responses to immune checkpoint blockade. We investigated whether PDP could enhance anti-PD1 therapy responses in PDAC using patient-derived organoids (PDOs). PDOs were treated with Visudyne and red light (25, 75, and 100 J/cm²), followed by assessment of cytotoxicity, DAMP expression (HSP60, calreticulin, HMGB1), and transcriptomic changes. Monocyte-derived dendritic cells (mDCs) from healthy donors were cocultured with PDP-treated (25 J/cm 2 ) PDOs, then with matched naïve T cells. mDC and T cell activation markers were analyzed. Pembrolizumab (anti-PD1) was added to PDO-mDC-T cell cocultures to evaluate combined effects on PDO viability and T cell activation. PDP induced dose-dependent cytotoxicity and upregulated DAMPs. Gene profiling in PDOs showed increased IFN-γ , TNF-α , and CXCL12 , with reduced PD-L1 , TGF-β1 , and FOXP1 expression. mDCs exposed to PDP-treated PDOs upregulated CD40, CD86, and MHC-II, driving activation of CD4 + and CD8 + T cells, evidenced by elevated PD1 expression. Addition of pembrolizumab further decreased PDO viability and amplified effector cytokines ( IFN-γ , TNF-α , FASLG , granzyme B, IL-2 , IL-21 ). PDP was associated with modulation of the PDAC TME toward a more immunogenic phenotype by enhancing tumor immunogenicity, activating dendritic cells and T cells, and potentiating PD1 blockade. These findings provide mechanistic support for further preclinical and clinical evaluation of PDP combined with checkpoint inhibition in PDAC.

Abstract Background and Aims EUS-guided gastroenterostomy (EUS-GE) is an effective option to palliate symptoms of gastric outlet obstruction (GOO). While the jejunum is conventionally targeted (EUS-GJ), targeting the duodenum (EUS-GD) may offer clinical advantages. Outcomes were compared for EUS-GJ and EUS-GD. Methods Adult patients who underwent EUS-GE for GOO between 2020 and 2024 were included and categorized as an EUS-GD if the stent entered the transverse or ascending duodenum or an EUS-GJ if the stent entered more distally. The primary outcome was clinical success (soft diet tolerance at 7 days). Secondary outcomes included adverse events (AEs), stent misdeployment, and unplanned endoscopic reintervention. Baseline demographic variables and outcomes were compared with statistical significance at p < 0.05. Results Of the 139 included patients (median age 67 years (IQR 61–74); 41% female), 105 underwent EUS-GJ and 34 underwent EUS-GD. Clinical success was 98% for EUS-GJ and 94% for EUS-GD (p = 0.25). The misdeployment rate was 7% for EUS-GJ and 0% for EUS-GD (p = 0.19). The AE rate was 22% for EUS-GJ and 12% for EUS-GD (p = 0.23). There were no significant differences for stent obstruction (EUS-GJ 12% vs. EUS-GD 6%), bleeding (2% vs. 6%), perforation (4% vs. 0%), stent migration (1% vs. 0%), infection (3% vs. 0%), and unplanned reintervention (14% vs. 9%). Conclusion Both EUS-GJ and EUS-GD demonstrate high clinical success with no significant differences in adverse event rates. These data can support intraprocedural decision-making for endoscopists performing EUS-GE.

Background: Self-expanding metal stents (SEMS) are recommended for the endoscopic palliation of distal malignant biliary obstruction (DMBO). Placement of SEMS during endoscopic retrograde cholangiopancreatography (ERCP) has been associated with an increased risk of post-ERCP pancreatitis (PEP). Objectives: The aim of this study is to evaluate rates of PEP in patients who underwent SEMS placement for pancreatic versus non-pancreatic malignancy. Design: Retrospective Cohort Study. Methods: Patients who underwent SEMS placement for DMBO between June 2017 and May 2021 were identified retrospectively from a procedural billing database. PEP incidence was compared between pancreatic and non-pancreatic DMBO groups and multivariate logistic regression was performed to identify risk factors for PEP. Results: A total of 488 individuals were identified, with 395 (80.9%) cases of DMBO due to pancreatic and 93 (19.1%) due to non-pancreatic malignancy. Stent types included 124 (25.4%) fully covered (FCSEMS) and 364 (74.6%) uncovered metal stents (UCSEMS). The overall rate of PEP in the cohort was 6.3% with no significant difference between pancreatic and non-pancreatic etiologies (6.1% vs 7.5%, p = 0.606). When adjusted for age <50 years old, female sex, and pancreatic stent placement, a non-pancreatic malignancy was not associated with an increased risk of PEP (OR 0.83, 95% CI 0.36–2.15). Conclusion: No statistically significant difference in PEP rates was seen after biliary sphincterotomy and SEMS placement for palliation of DMBO in patients with pancreatic versus non-pancreatic malignancies.

Abstract Endoscopic retrograde cholangiopancreatography (ERCP)-based tissue acquisition is the cornerstone for assessment of suspected malignant biliary strictures. Conventional techniques, including biliary brush cytology and transpapillary forceps biopsy, are highly specific but are limited by modest sensitivity for detection of malignancy, often leaving a substantial proportion of individuals without a definitive diagnosis. To improve diagnostic sensitivity for cancer, several adjunctive approaches have been integrated into ERCP-based sampling. Peroral cholangioscopy (POC)-guided biopsies have become a reliable ERCP-based adjunctive modality, allowing direct visualization and targeted sampling, particularly in individuals with prior nondiagnostic procedures. Fluorescence in situ hybridization (FISH) is a technique used to improve diagnostic yield with biliary brushings by detecting chromosomal abnormalities, but is limited to specialized centers due to the need for specialized processing and training. Next-generation sequencing provides high sensitivity and can enable identification of actionable genomic alterations, while methylated DNA markers represent a promising, scalable molecular approach with strong diagnostic performance. Additional techniques include artificial intelligence–augmented direct visualization by POC and bile-based liquid biopsy. Current guidelines recommend multimodal ERCP-based sampling, combining at least two modalities where feasible, to optimize diagnostic accuracy. This review highlights the clinical performance, strengths, and limitations of established and emerging ERCP-guided techniques, emphasizing their evolving role in improving the diagnosis and management of malignant biliary strictures.

Malignant hilar biliary obstruction (MHBO) is most commonly caused by cholangiocarcinoma or gallbladder cancer and frequently presents with obstructive jaundice, pruritus, and/or cholangitis. These symptoms impair performance status and delay the initiation of chemotherapy, making biliary drainage essential for both palliation and oncologic treatment. Endoscopic transpapillary biliary stenting via endoscopic retrograde cholangiopancreatography is the standard approach for biliary decompression. In patients with unresectable disease, either plastic or self-expandable metal stents may be used. Optimal outcomes are achieved when drainage encompasses more than 50% of functional liver volume, while atrophic segments should be avoided. When transpapillary access is not feasible or unsuccessful, alternative approaches such as percutaneous transhepatic biliary drainage or endoscopic ultrasound-guided biliary drainage may be considered. Adjunctive therapies, including photodynamic therapy and radiofrequency ablation, are being investigated to enhance local tumor control and prolong stent patency. With continued advances in stent technology, imaging modalities, and endoscopic techniques, the management of MHBO is expected to become increasingly individualized and effective.

Abstract Pancreatic ductal adenocarcinoma (PDAC) is unresponsive to immune checkpoint therapies largely due to immunosuppression mediated by myeloid and lymphoid cells. Effective treatment strategies require, in addition to immune stimulation, the depletion of these immunosuppressive cells and their interactions. Here, we demonstrate for the first time, that a single verteporfin-based photodynamic therapy (PDT) treatment triples median survival in a KPC-PDAC model when combined with anti-PD1 therapy. Mechanistically, apart from reducing CK19 + tumor cells, PDT depletes immunosuppressive myeloid (CD11c+) and lymphoid (FOXP3+) cell populations, by ~ 4- and ~ 18.4-folds, respectively. PDT further disrupts interactions between these immunosuppressive cells, attenuating a key immune-tolerance axis. At the systemic level, PDT reduces splenic immunosuppression through modulation of tumor-derived cytokines. Within this reprogrammed immune-landscape, anti–PD-1 therapy elicits robust CD8 + T-cell responses, reflected by an ~ 6.7-fold increase in the intratumoral CD8+/Treg ratio. Collectively, these findings establish verteporfin-PDT as an immune-priming strategy that complements anti–PD-1 therapy by alleviating immunosuppression in PDAC.