Outcome of patients with perihilar cholangiocarcinoma and previous biliary instrumentation: an observational study.

BACKGROUND: To assess the outcome of previously untreated patients with perihilar cholangiocarcinoma who present to a cancer referral center with or without pre-existing trans-papillary biliary drainage. METHODS: Consecutive patients with a diagnosis of perihilar cholangiocarcinoma presenting between January 1, 2013, and December 31, 2017, were identified from a prospective surgical database and by a query of the institutional database. Of 237 patients identified, 106 met inclusion criteria and were reviewed. Clinical information was obtained from the Electronic Medical Record and imaging studies were reviewed in the Picture Archiving and Communication System. RESULTS: 73 of 106 patients (69%) presenting with a new diagnosis of perihilar cholangiocarcinoma underwent trans-papillary biliary drainage (65 endoscopic and 8 percutaneous) prior to presentation at our institution. 8 of the 73 patients with trans-papillary biliary drainage (11%) presented with and 5 developed cholangitis; all 13 (18%) required subsequent intervention; none of the patients without trans-papillary biliary drainage presented with or required drainage for cholangitis (p = 0.008). Requiring drainage for cholangitis was more likely to delay treatment (p = 0.012) and portended a poorer median overall survival (13.6 months, 95%CI [4.08, not reached)] vs. 20.6 months, 95%CI [18.34, 37.51] p = 0.043). CONCLUSION: Trans-papillary biliary drainage for perihilar cholangiocarcinoma carries a risk of cholangitis and should be avoided when possible. Clinical and imaging findings of perihilar cholangiocarcinoma should prompt evaluation at a cancer referral center before any intervention. This would mitigate development of cholangitis necessitating additional drainage procedures, delaying treatment and potentially compromising survival.

Real-life patency of plastic biliary stents in the pandemic era: is stent removal after 6 months safe and effective?

BACKGROUND: The SARS-CoV-2 pandemic conditioned the optimal timing of some endoscopic procedures. ESGE guidelines recommend replacement or removal of the plastic biliary stents within 3-6 months to reduce the risk of complications. Our aim was to analyse the outcomes of patients who had delayed plastic biliary stent removal following endoscopic retrograde cholangiopancreatography (ERCP) in the pandemic era. METHODS: Retrospective study including consecutive ERCPs with plastic biliary stent placement between January 2019 and December 2021. Delayed removal was defined as presence of biliary stent >6 months after ERCP. The evaluated outcomes were stent migration, stent dysfunction, obstructive jaundice, cholangitis, acute pancreatitis, hospitalization, and biliary pathology-related mortality. RESULTS: One-hundred and twenty ERCPs were included, 56.7% male patients, with a mean age of 69.4 ± 15.7 years. Indications for plastic biliary stent insertion were choledocholithiasis (72.5%), benign biliary stricture (20.0%), and post-cholecystectomy fistula (7.5%). Delayed stent removal occurred in 32.5% of the cases. The median time to stent removal was 3.5 ± 1.3 months for early removal and 8.6 ± 3.1 months for delayed removal. Patients who had delayed stent removal did not have a significantly higher frequency of stent migration (20.5 vs 11.1%, p = 0.17), stent dysfunction (17.9 vs 13.6%, p = 0.53), hospitalization (17.9 vs 14.8%, p = 0.66), obstructive jaundice (2.6 vs 0.0%, p = 0.33), cholangitis (10.3 vs 13.6%, p = 0.77), acute pancreatitis (0.0 vs 1.2%, p = 1.0), or biliary pathology-related mortality (2.6 vs 1.2%, p = 0.55). CONCLUSIONS: Delayed plastic biliary stent removal does not seem to have a negative impact on patients' outcomes. In the current pandemic situation, while scheduled endoscopic procedures may have to be postponed, elective removal of plastic biliary stents can be safely deferred.

Sems Sensibility: Biliary Stent Migration into the Oesophagus.

Endoprostheses are commonly used in the treatment of biliary and pancreatic disorders. Fully-covered metal stents are intended for the palliation of malignant strictures in the biliary tree. We report a case of a patient affected by cancer of the pancreas who was treated with a proximal metallic biliary stent. The stent migrated to the oesophagus and was endoscopically removed. Proximal migration, although rare, should be kept in mind as a potential complication of the procedure.

Antimigration versus conventional fully covered metal stents in the endoscopic treatment of anastomotic biliary strictures after deceased-donor liver transplantation.

INTRODUCTION: Migration of fully covered metal stents (FCMS) remains a limitation of the endoscopic treatment of anastomotic biliary strictures (ABS) following orthotopic liver transplantation (OLT). The use of antimigration FCMS (A-FCMS) might enhance endoscopic treatment outcomes for ABS. METHODS: Single center retrospective study. Consecutive patients with ABS following OLT who underwent ERCP with FCMS placement between January 2005 and December 2020 were eligible. Subjects were grouped into conventional-FCMS (C-FCMS) and A-FCMS. The primary outcome was stent migration rates. Secondary outcomes were stricture resolution, adverse event, and recurrence rates. RESULTS: A total of 102 (40 C-FCMS; 62 A-FCMS) patients were included. Stent migration was identified at the first revision in 24 C-FCMS patients (63.2%) and in 21 A-FCMS patients (36.2%) (p = 0.01). The overall migration rate, including the first and subsequent endoscopic revisions, was 65.8% in C-FCMS and 37.3% in A-FCMS (p = 0.006). The stricture resolution rate at the first endoscopic revision was similar in both groups (60.0 vs 61.3%, p = 0.87). Final stricture resolution was achieved in 95 patients (93.1%), with no difference across groups (92.5 vs 93.5%; p = 0.84). Adverse events were identified in 13 patients (12.1%) with no difference across groups. At a median follow-up of 52 (IQR: 19-85.5) months after stricture resolution, 25 patients (24.5%) developed recurrences, with no difference across groups (C-FCMS 30% vs A-FCMS 21%; p = 0.28). CONCLUSIONS: The use of A-FCMS during ERCP for ABS following OLT results in significantly lower stent migration rates compared to C-FCMS. However, the clinical benefit of reduced stent migration is unclear. Larger studies focusing on stricture resolution and recurrence rates are needed.

Comparable Efficacy of Laser-Cut and Braided Self Expanding Metallic Biliary Stent: A Systematic Review and Meta-Analysis.

BACKGROUND AND AIMS: In patients with unresectable malignant biliary obstruction (MBO), endoscopic biliary drainage is the treatment of choice. Self-expanding metallic stents (SEMS) are mainly used for this purpose, and data is limited on the comparative outcomes of laser-cut versus braided SEMS. Herein, we performed the first systematic review and meta-analysis to study the effectiveness and safety of braided and laser-cut SEMS in MBO. METHODS: Multiple databases, including Medline, Scopus, and Embase, were searched (in May 2022) using specific terms for studies evaluating the outcomes of braided and laser-cut SEMS in MBO. Outcomes of interest were technical and clinical success, recurrent biliary obstruction, and adverse events. Standard meta-analysis methods were employed using the random-effects model. I2% heterogeneity was used to assess the heterogeneity. RESULTS: Seven studies were included in the final analysis. (Laser-cut: 271 patients, 46% females, mean age 70 years; and braided: 282 patients, 47% females, mean age 72 years). The pooled rate of technical success and clinical success with laser-cut SEMS was 99% (95% CI [95-99; I2 = 0%]), 86% [60-96; I2 = 74%], and 98% [96-99; I2 = 0%], 89% [74-95; I2 = 78%] with braided. The pooled rate of recurrent biliary obstruction with laser-cut SEMS was 26% [14-43; I2 = 88%] and 12% [5-27; I2 = 56%) with braided. Pooled total adverse events were 11% [5-21; I2 = 77%] in laser-cut and 12% [6-24; I2 = 63%] in braided. CONCLUSION: Our meta-analysis demonstrates similar clinical outcomes with laser-cut and braided SEMS in MBO. Given the comparable performance, a cost-effectiveness analysis might help in choosing one type versus another in patients with MBO.

Cardiac tamponade and septic pericarditis caused by biliary stent migration.

In patients with biliary or pancreatic disease, endoscopic retrograde cholangiopancreatography (ERCP) is a common and important therapeutic and diagnostic procedure. Stent migration is a possible complication occurring in approximately 5-10% of cases. This case presents a 47-year-old male with chest pain and found to have biliary stent migration to the pericardial sac causing septic pericarditis and cardiac tamponade. Highlighting this devastating complication, this case demonstrates an opportunity for emergency physicians (EP) to diagnose and monitor patients for post-operative and post-procedural complications. In the emergency department, EPs are well positioned to use ultrasound as a diagnostic and monitoring tool for cardiac tamponade.

Comparison of MR-soft tissue based versus biliary stent based alignment for image guidance in pancreatic SBRT.

PURPOSE: The role of biliary stents in image-guided localization for pancreatic cancer has been inconclusive. To date, stent accuracy has been largely evaluated against implanted fiducials on cone beam computed tomography. We aim to use magnetic resonance (MR) soft tissue as a direct reference to examine the geometric and dosimetric impacts of stent-based localization on the newly available MR linear accelerator. METHODS: Thirty pancreatic cancer patients (132 fractions) treated on our MR linear accelerator were identified to have a biliary stent. In our standard adaptive workflow, patients were set up to the target using soft tissue for image registration and structures were re-contoured on daily MR images. The original plan was then projected on treatment anatomy and dose predicted, followed by plan re-optimization and treatment delivery. These online predicted plans were soft tissue-based and served as reference plans. Retrospective image registration to the stent was performed offline to simulate stent-based localization and the magnitude of shifts was taken as the geometric accuracy of stent localization. New predicted plans were generated based on stent-alignment for dosimetric comparison. RESULTS: Shifts were within 3 mm for 90% of the cases (mean = 1.5 mm); however, larger shifts up to 7.2 mm were observed. Average PTV coverage dropped by 1.1% with a maximum drop of 26.8%. The mean increase in V35Gy was 0.15, 0.05, 0.02, and 0.02 cc for duodenum, stomach, small bowel and large bowel, respectively. Stent alignment was significantly worse for all metrics except for small bowel (p = 0.07). CONCLUSIONS: Overall discrepancy between stent- and soft tissue-alignment was modest; however, large discrepancies were observed for select cases. While PTV coverage loss may be compensated for by using a larger margin, the increase in dose to gastrointestinal organs at risk may limit the role of biliary stents in image-guided localization.

Bronchobiliary fistula after stenting of biliary duct as the management of iatrogenic bile duct injury during elective cholecystectomy.

BACKGROUND: Bronchobiliary fistula is a rare and complex entity defined by an abnormal communication between the biliary and bronchial systems. The etiopathogenesis is not completely understood, but the most common factors implicated are hepatobiliary tumors, biliary obstruction, iatrogenic damage or trauma. METHODS: Here we present a case of a 69-year-old man that developed a bronchobiliary fistula and a pulmonary abscess after migration of a bile duct stent placed as part of the treatment of an iatrogenic bile duct injury that occurred during elective cholecystectomy. RESULTS: A conservative approach, that included broad-spectrum antibiotic, removal of the stent, and sphincterotomy, was enough for the closure of the fistula and resolution of the symptoms. CONCLUSION: We emphasize the importance of prompt recognition of this entity and a concerted therapeutic strategy to optimize the probability of success, avoiding the destructive consequences of the bile in the pulmonary parenchyma and septic complications.

Prognostic nomogram for acute pancreatitis after percutaneous biliary stent insertion in patients with malignant obstruction.

OBJECTIVE: This study aimed to develop and validate a nomogram to predict the risk of pancreatitis after percutaneous transhepatic biliary stent insertion (PTBS) in patients with malignant biliary obstruction (MBO). MATERIALS AND METHODS: We enrolled 314 patients who underwent PTBS for MBO from March 2016 to July 2021 in this retrospective study. We used univariate analysis to identify potential risk factors, while a multivariate logistic regression model was employed to establish a nomogram for predicting the risk of pancreatitis. The discrimination and calibration of the nomogram were evaluated by estimating the area under the receiver operator characteristic curve (AUC) and by bootstrap resampling and visual inspection of the calibration curve. The clinical utility of the nomogram was assessed using decision curve analysis (DCA). RESULTS: After the procedure, 41 (13.1%) patients developed pancreatitis. Based on multivariate logistic regression analysis, young age (OR = 2.57, 95% CI 1.16 to 5.69), stent insertion across the papilla (OR = 6.47, 95% CI 2.66 to 15.70), and visualization of the pancreatic duct (OR = 15.40, 95% CI 6.07 to 39.03) were associated with an elevated risk of pancreatitis. Importantly, the performance of the nomogram was satisfactory, with an identical AUC (0.807, 95% CI 0.730 to 0.883) and high-level agreement between predicted and observed probabilities as suggested in calibration curves. The DCA curve subsequently confirmed the clinical utility. CONCLUSION: A predictive nomogram for pancreatitis after PTBS in patients with MBO was successfully established in the present study.

Biliary Sphincterotomy Alone versus Biliary Stent with or without Biliary Sphincterotomy for the Management of Post-Cholecystectomy Bile Leak: A Systematic Review and Meta-Analysis.

BACKGROUND: Endoscopic therapy with endoscopic retrograde cholangiopancreatography is considered the first-line treatment in the management of post-cholecystectomy bile leak (PCBL). Currently, there is no consensus on the most effective endoscopic intervention for PCBL. Hence, we performed a systematic review and meta-analysis to compare the effectiveness and safety of the two interventional groups (biliary sphincterotomy [BS] alone vs. biliary stent ± BS) in management of PCBL. METHODS: We conducted a comprehensive search of multiple electronic databases and conference proceedings (from inception through January 2021). The primary outcome was to compare the pooled rate of clinical success between the 2 groups. The secondary outcome was to estimate the pooled rate of adverse events. RESULTS: The pooled rate of clinical success with BS alone (5 studies, 299 patients) was 88% (95% confidence interval (CI): 84-92%, I2: 0%) and for biliary stent ± BS (5 studies, 864 patients) was 97% (CI: 93-100%, I2: 79%). The rate of clinical success in biliary stent ± BS group was significantly higher than BS alone group (OR: 3.91 95% CI: 2.29-6.69, p < 0.001, I2: 13%). The rate of adverse events was numerically lower in biliary stent ± BS group compared to BS alone (3 studies; OR: 0.65 95% CI: 0.41-1.03, p = 0.07) without statistical significance. Low heterogeneity was noted in the analysis. CONCLUSIONS: Biliary stent ± BS is more effective in endoscopic management of PCBL compared to BS alone. This may be related to inter-endoscopist variation in completeness of sphincterotomy and post-sphincterotomy edema, which can influence the preferential trans-papillary flow of bile.

Incidence of complications associated to bile duct stents, in patients with advanced cancer: a single-center experience.

BACKGROUND: Pancreatic cancer (PCa) and biliary tract carcinomas (BTCa) have high morbidity and mortality rates. Bile duct obstruction (BDO) develops in approximately 65-75% of PCa at diagnosis, delaying the administration of optimal treatment. In patients not candidates for surgery, BDO is usually treated through the endoscopy-guided placement of self-expanding stents in the bile duct. METHODS: In this retrospective study, we sought to describe clinical characteristics and outcomes of a cohort of patients with BDO of malignant origin who underwent biliary stent placement (BSP), with a special focus regarding complications developed after the procedure. Patients with PCa, BTCa, colon cancer, lung cancer, gastric cancer, and ovarian cancer who underwent BSP from 2014 to April 2019 at our institution were included in this cohort. Demographic and clinicopathologic characteristics were collected. Statistical analysis stratified according to ECOG performance status. Specific information regarding stent material (metallic vs. plastic), as well as incidence and type of complications derived from BSP, was also recorded. RESULTS: One hundred fifteen patients were included. The median age was 72 years. Sixty-six patients (57%) had PCa. All patients presented hyperbilirubinemia, which decreased after the procedure in 111 (96%) patients. Complications were observed in 44 (38%) patients, most of which 33 (75%) were infections. The median time to the complication was 1 month. The mean overall survival (OS) in our study was 20.3 weeks. CONCLUSION: BSP effectively decreased hyperbilirubinemia in patients with BDO; however, the procedure associated a significant rate of infectious complications, which can further compromise an effective anti-cancer therapy as well as optimal palliative strategies.

Enteral extended biliary stents versus conventional plastic biliary stents for the treatment of extrahepatic malignant biliary obstruction: a single-center prospective randomized controlled study.

BACKGROUND AND AIMS: The main limitation of plastic stents is the relatively short stent patency due to occlusion. We designed enteral extended biliary stents with lengths of 26 cm (EEBS-26 cm) and 30 cm (EEBS-30 cm) to prolong stent patency. This study aimed to compare patency among EEBS-26 cm, EEBS-30 cm, and conventional plastic biliary stent (CPBS). METHODS: A single-center prospective randomized controlled study was conducted. Eligible patients were randomized into the EEBS-26 cm, EEBS-30 cm, and CPBS groups, respectively. All patients were followed up every 3 months until stent occlusion, patient death, or at 12-month follow-up. The primary outcome was stent patency. The secondary outcomes included stent occlusion rate, patient survival, mortality, the rate of technical success, and adverse events. RESULTS: Totally 117 patients were randomized into the three groups. There were no significant differences among the three groups in technical success rate, hospital stay, mortality, patient survival, and adverse events (P = 1.000, 0.553, 0.965, 0.302, and 0.427, respectively). Median stent patency durations in the EEBS-26 cm, EEBS-30 cm, and CPBS groups were 156.0 (95% CI 81.6-230.4) days, 81.0 (95% CI 67.9-94.1) days, and 68.0 (95% CI 20.0-116.0) days, respectively (P = 0.002). The EEBS-26 cm group had longer stent patency compared with the CPBS (P = 0.007) and EEBS-30 cm (P < 0.001) groups. The EEBS-26 cm group had lower stent occlusion rates compared with the other groups at 6 months (48.1% vs. 90.5% vs. 82.8%, P = 0.001) and 9 months (75.0% vs. 100.0% vs. 92.9%, P = 0.022). CONCLUSION: EEBS-26 cm has prolonged stent patency and is safe and effective for the alleviation of unresectable extrahepatic malignant biliary obstruction.

Safety and Efficacy of Gemcitabine Plus Nab-Paclitaxel for Metastatic Pancreatic Cancer Patients Undergoing Biliary Stent Placement.

BACKGROUND: Gemcitabine plus nab-paclitaxel (GnP) is the first-line chemotherapeutic regimen for metastatic pancreatic cancer (MPC); however, there are concerns regarding its safety in patients undergoing biliary stent placement. This study aimed to examine the tolerability and efficacy of GnP in MPC patients who underwent biliary stent placement. METHODS: A total of 105 MPC patients who had received GnP treatment between 2015 and 2020 were included and investigated. The patients were divided into two groups: those undergoing biliary stent placement for symptomatic biliary obstruction (BO) (With-BO group) and those without biliary stent placement (Without-BO group). The best tumor response, overall survival (OS), and adverse events in each group were compared. RESULTS: The partial response, stable disease, and progressive disease rates were 22%, 61%, and 14.6% in the With-BO group, and 26.6%, 46.9%, and 21.9% in the Without-BO group, respectively, with no significant differences. The median OS was 12.2 months and 14.6 months in the With-BO and Without-BO groups, respectively (P = 0.483). Grade 3 or higher biliary tract-related events were significantly more common in the With-BO group (41.5%) than in the Without-BO group (1.6%) (P < 0.001), but all events were managed successfully by urgent intervention. The rates of any treatment-related toxicities, including febrile neutropenia, were not significantly different, and there were no chemotherapy-related deaths in either group. CONCLUSIONS: GnP can be as tolerable and effective in MPC patients with biliary stents as in those without biliary stents. However, careful management and appropriate reintervention to treat biliary tract-related adverse events are required.

Local palliative therapies for unresectable malignant biliary obstruction: radiofrequency ablation combined with stent or biliary stent alone? An updated meta-analysis of nineteen trials.

BACKGROUND: Recently, there has been a burgeoning interest in radiofrequency ablation combined with stent (RFA + Stent) for unresectable malignant biliary obstruction (MBO). This study aimed to perform a meta-analysis to evaluate the efficacy and safety of RFA + Stent compared with biliary stent alone. METHODS: We searched PubMed, Cochrane Library, Embase, and Web of Science databases from their inception dates to June 20, 2021, for studies that compared RFA + Stent and stent alone for unresectable MBO. The main outcomes were survival, patency, and adverse effects. All meta-analyses were calculated using the random-effects model. RESULTS: A total of 19 studies involving 1946 patients were included in this study. Compared with stent alone, RFA + Stent was significantly associated with better overall survival (HR 0.55; 95% CI 0.48, 0.63; P < 0.00001), longer mean survival time (SMD 2.20; 95% CI 1.17, 3.22; P < 0.0001), longer mean stent patency time (SMD 1.37; 95% CI 0.47, 2.26; P = 0.003), higher stent patency at 6 months (OR 2.82; 95% CI 1.54, 5.18; P = 0.0008). The two interventions had similar incidence of postoperative abdominal pain (OR 1.29; 95% CI 0.94, 1.78; P = 0.11), mild bleeding (OR 1.28; 95% CI 0.65, 2.54; P = 0.48), cholangitis (OR 1.09; 95% CI 0.76, 1.55; P = 0.65), pancreatitis (OR 1.39; 95% CI 0.82, 2.38; P = 0.22). Furthermore, the serum bilirubin levels and stricture diameter after operations were significantly alleviated than before operations, but the degree of alleviation between the two groups were not significantly different (all P > 0.05). CONCLUSION: Although the alleviation of serum bilirubin and stricture diameter did not differ between the two interventions, RFA + Stent can significantly improve the survival and stent patency with comparable procedure-related adverse events than stent alone. Thus, RFA + Stent should be recommended as an attractive alternative to biliary stent alone for patients with unresectable MBO.

Heating of metallic biliary stents during magnetic hyperthermia of patients with pancreatic ductal adenocarcinoma: an in silico study.

OBJECTIVE: To investigate the eddy current heating that occurs in metallic biliary stents during magnetic hyperthermia treatments and to assess whether these implants should continue to be an exclusion criterion for potential patients. METHODS: Computer simulations were run on stent heating during the hyperthermia treatment of local pancreatic tumors (5-15 mT fields at 300 kHz for 30 min), considering factors such as wire diameter, type of stent alloy, and field orientation. Maxwell's equations were solved numerically in a bile duct model, including the secondary field produced by the stents. The heat exchange problem was solved through a modified version of the Pennes' bioheat equation assuming a temperature dependency of blood perfusion and metabolic heat. RESULTS: The choice of alloy has a large impact on the stent heating, preferring those having a lower electrical conductivity. Only for low field intensities (5 mT) and for some of the bile duct tissue layers the produced heating can be considered safe. The orientation of the applied field with respect to the stent wires can give rise to the onset of regions with different heating levels depending on the shape that the stent has finally adopted according to the body's posture. Bile helps to partially dissipate the heat that is generated in the lumen of the bile duct, but not at a sufficient rate. CONCLUSION: The safety of patients with pancreatic cancer wearing metallic biliary stents during magnetic hyperthermia treatments cannot be fully assured under the most common treatment parameters.

Early migration of biliary stent leading to free intra-peritoneal duodenal perforation - A case report.

Intestinal perforation from a plastic biliary stent is a known but rare complication of endoscopic biliary stent placement. Intra-peritoneal perforation is less common but carries more morbidity and mortality. Only a few cases of early stent migration and perforation have been reported. We present the case of a duodenal perforation caused by early migration of plastic biliary stent that resulted in intra-peritoneal biliary peritonitis.

Bacterial Pericarditis Caused by Penetration of a Migrated Biliary Stent from the Lateral Segment of the Liver: A Case Report.

Endoscopic biliary stent insertion is a well-established procedure that is indispensable in the management of various benign and malignant biliary disorders, and one that helps prevent mortality related to invasive surgical procedures. We report a rare case of the distal migration of a biliary stent outside the abdomen to the pericardium, inducing constrictive pericarditis and septic shock. This case alerts clinicians to be aware of potential adverse events that can lead to unfavorable patient outcomes. Such adverse events can be effectively avoided through early detection and intervention.

Migration of biliary stent into the gallbladder: A surprising intraoperative finding.

Post-endoscopic retrograde cholangiopancreatography stenting is a well-established treatment for benign as well as malignant biliary obstruction. The most frequently encountered complication is stent clogging. Stent migration (proximal or distal), on the other hand, is not very common. Proximal migration of a choledochal endoprosthesis into the gallbladder has not yet been reported in the literature.

Role of biliary stent and neoadjuvant chemotherapy in the pancreatic tumor microbiome.

BACKGROUND: Intra-tumor microbiota have been implicated in pancreatic ductal adenocarcinoma (PDAC) development, treatment response and post-treatment survivorship. Moreover, therapeutic interventions targeting microbiota may improve the response to chemotherapy and immunotherapy, further emphasizing the critical need to understand the origins of and growth of bacteria within the pancreatic tumor microenvironment. Here, we studied the role of several clinical factors on the bacterial colonization of PDAC. RESULTS: We obtained matched tumor and normal pancreatic tissue specimens from 27 patients who had undergone surgical resection for PDAC between 2011 and 2015 from the University of Minnesota Biological Materials Procurement Network (BioNet). We found that 26 (48%) out of 54 pancreatic tissue samples harbored detectable bacterial communities using real-time PCR targeting the 16S rRNA gene. Bacterial colonization was detected significantly more frequently in samples from patients who had pancreatic head tumors, underwent Whipple procedure, or had preoperative biliary stent placement. There was also a significantly greater relative abundance of microbiota from the family Enterobacteriaceae among samples from patients who underwent biliary stent placement or neoadjuvant treatment with a combination of Gemcitabine and Paclitaxel. CONCLUSIONS: These findings suggest that biliary stent placement and neoadjuvant chemotherapy are associated with specific alterations that promote the infiltration and growth of intra-tumor bacteria in the setting of PDAC. Further studies exploring whether specific bacterial communities could contribute to increased chemoresistance will be essential for optimizing medical therapies in the future.

Fishing line assisted endoscopic placement of multiple plastic biliary stents for unresectable malignant hilar biliary obstruction: a retrospective study.

BACKGROUND AND AIMS: Stent migration is one of the most common complications during the placement of multiple plastic biliary stents (MPBS) under endoscopy. This study aims to evaluate the feasibility and efficiency of the fishing line assisted (FLA) method for preventing the complication. METHODS: Patients with unresectable malignant hilar biliary obstruction (MHBO) who undergone endoscopic placement of MPBS using the FLA or conventional method from May 2018 to April 2021 in our center were enrolled in the study. The endpoints of this study were the stent migration rate, technical success rates, adverse events rates, times of stent migration, and the procedure time. RESULTS: FLA group (N = 19) and conventional group (N = 22) had similar baseline characteristics of the patients. The technical success rates (100% vs. 95.5%; P > 0.05), ERCP-related adverse events rates (5.3% vs. 4.5%; P > 0.05), and the stent-related adverse events rates (0% vs. 4.5%; P > 0.05) were no significant differences between the FLA and conventional groups. MPBS inserted using the conventional method consumed more time (median, 33.9 min vs. 15.6 min; P < 0.05) method and increased the times of stent migration (median, 3 times vs. 0 times; P < 0.05) than using the FLA method. Even if no statistical difference was detected in the stent migration rate between groups, this rate was lower in the FLA group than the conventional group (0% vs. 13.6%; P > 0.05). CONCLUSIONS: FLA method is an effective technique for MPBS implantation to prevent stent migration during endoscopic retrograde cholangiography (ERCP). The method should be applied to patients with unresectable MHBO who need to place MPBS.