Post-ERCP pancreatitis and its prevention

Rectal administration of tacrolimus protects against post-ERCP pancreatitis in mice

OBJECTIVE

There is an unmet clinical need for effective, targeted interventions to prevent post-ERCP pancreatitis (PEP). We previously demonstrated that the serine-threonine phosphatase, calcineurin (Cn) is a critical mediator of PEP and that the FDA-approved calcineurin inhibitors, tacrolimus (Tac) or cyclosporine A, prevented PEP. Our recent observations in preclinical PEP models demonstrating that Cn deletion in both pancreatic and hematopoietic compartments is required for maximal pancreas protection, highlighted the need to target both systemic and pancreas-specific Cn signaling. We hypothesized that rectal administration of Tac would effectively mitigate PEP by ensuring systemic and pancreatic bioavailability of Tac. We have tested the efficacy of rectal Tac in a preclinical PEP model and in cerulein-induced experimental pancreatitis.

METHODS

C57BL/6 mice underwent ductal cannulation with saline infusion to simulate pressure-induced PEP or were given seven, hourly, cerulein injections to induce pancreatitis. To test the efficacy of rectal Tac in pancreatitis prevention, a rectal Tac suppository (1 mg/kg) was administered 10 min prior to cannulation or first cerulein injection. Histological and biochemical indicators of pancreatitis were evaluated post-treatment. Pharmacokinetic parameters of Tac in the blood after rectal delivery compared to intravenous and intragastric administration was evaluated.

RESULTS

Rectal Tac was effective in reducing pancreatic injury and inflammation in both PEP and cerulein models. Pharmacokinetic studies revealed that the rectal administration of Tac helped achieve optimal blood levels of Tac over an extended time compared to intravenous or intragastric delivery.

CONCLUSION

Our results underscore the effectiveness and clinical utility of rectal Tac for PEP prophylaxis.

Preclinical safety evaluation of calcineurin inhibitors delivered through an intraductal route to prevent post-ERCP pancreatitis demonstrates endocrine and systemic safety

OBJECTIVE

There is an urgent need for safe and targeted interventions to mitigate post-ERCP pancreatitis (PEP). Calcineurin inhibitors (CnIs) offer therapeutic promise as calcineurin signaling within acinar cells is a key initiating event in PEP. In previous proof-of-concept studies using experimental models, we showed that concurrent intra-pancreatic ductal administration of the CnIs, tacrolimus (Tac) or cyclosporine A (CsA) with the ERCP radiocontrast agent (RC) prevented PEP. To translate this finding clinically, we investigated potential toxic effects of intraductal delivery of a single-dose RC-CnI formulation on endocrine pancreas function and systemic toxicities in a preclinical PEP model.

METHODS

C57BL/6J mice underwent ductal cannulation and received a single, intra-pancreatic ductal infusion of RC or RC with Tac or CsA (treatment groups) or underwent ductal cannulation without infusion ('sham' group). To assess endocrine function, intraperitoneal glucose tolerance test (IPGTT) was performed at two days before infusion and on day 2 and 14 post-surgery. To evaluate off-target tissue toxicities, renal and hepatic function-related parameters including blood urea nitrogen, plasma creatinine, potassium, aspartate aminotransferase, alanine aminotransferase, and total bilirubin were measured at the same time-points as IPGTT. Histological and biochemical indicators of pancreas injury and inflammation were also evaluated.

RESULTS

No abnormalities in glucose metabolism, hepatic or renal function were observed on day 2 or 14 in mice administered with intraductal RC or RC with Tac or CsA.

CONCLUSION

Intraductal delivery of RC-CnI formulation was safe and well-tolerated with no significant acute or subacute endocrine or systemic toxicities, underscoring its clinical utility to prevent PEP.

Endoscopic or percutaneous biliary drainage in hilar cholangiocarcinoma: When and how?

Hilar cholangiocarcinoma (hCCA) is a primary liver tumor associated with a dim prognosis. The role of preoperative and palliative biliary drainage has long been debated. The most common techniques are endoscopic retrograde cholangiopancreatography (ERCP) and percutaneous transhepatic biliary drainage (PTBD); however, recently developed endoscopic ultrasound-assisted methods are gaining more atention. Selecting the best available method in any specific scenario is crucial, yet sometimes challenging. Thus, this review aimed to discuss the available techniques, indications, perks, pitfalls, and timing-related issues in the management of hCCA. In a preoperative setting, PTBD appears to have some advantages: low risk of postprocedural complications (namely cholangitis) and better priming for surgery. For palliative purposes, we propose ERCP/PTBD depending on the experience of the operators, but also on other factors: the level of bilirubin (if very high, rather PTBD), length of the stenosis and the presence of cholangitis (PTBD), ERCP failure, or altered biliary anatomy.

IV Ibuprofen for Prevention of Post-ERCP Pancreatitis in Children: A Randomized Placebo-controlled Feasibility Study

BACKGROUND

Post-endoscopic retrograde cholangiopancreatography (post-ERCP) pancreatitis (PEP) is reported to occur in up to 11% of pediatric patients. To date, no study has prospectively evaluated an intervention to prevent PEP in children. It is unclear if such a study is even feasible.

OBJECTIVE

The aim of the study was to evaluate the feasibility of studying IV ibuprofen for PEP prevention in the pediatric population.

METHODS

This was a prospective randomized double-blind placebo-controlled feasibility study. Patients younger than 19 years of age undergoing ERCP were randomized to receive 10 mg/kg IV ibuprofen (max of 800 mg) or placebo (saline) at the time of ERCP. The primary outcome was PEP. Secondary outcomes included post-ERCP-related bleeding, rates of other procedural and medication-related adverse events.

RESULTS

Fifty-eight patients were randomized and received either IV ibuprofen or placebo. Preprocedure- and procedure-related factors were not significantly different between the groups except that patients in the placebo group tended to weigh less (48.7 vs 63.7 kg, P = 0.03). There were 7 episodes of PEP (12%). PEP was less frequently identified in the Ibuprofen group than in the control group (7% vs 17%), but this was not statistically significant (P = 0.42). Mean postprocedural abdominal pain scores were significantly lower in the IV Ibuprofen group than in the control group (1.1 vs 3.1, P = 0.01) and the number of patients who had increased abdominal pain after the procedure was significantly lower in ibuprofen group than in the control group (3% vs 38%, P = 0.002). There were no significant differences in procedure-related or drug-related adverse events.

CONCLUSIONS

Postprocedural pain scores and the number of patients who had increased abdominal pain after the procedure were significantly lower in the IV ibuprofen group. The current study provides encouraging, but only very weak evidence that IV ibuprofen decreases PEP in children. Power analysis suggests that a small handful of high-volume pediatric centers would be able to perform an adequate clinical trial in a reasonable time frame. Focusing on all cause postprocedural pain (PEP and non-PEP) may allow for a more efficiency study design and be just as clinically relevant.

Pancreatic Stenting Reduces Post-ERCP Pancreatitis and Biliary Sepsis in High-Risk Patients: A Randomized, Controlled Study

Background. Endoscopic retrograde cholangiopancreatography (ERCP) is an established treatment modality for bile duct disorders, but patients have a risk of post-ERCP pancreatitis (PEP) and biliary sepsis. Aim. To evaluate the effectiveness and safety of pancreatic stent for prophylaxis of PEP and biliary sepsis in high-risk patients with complicating common bile duct (CBD) disorders. Methods. Two hundred and six patients with complicating confirmed or suspected CBD disorders were randomly assigned to receive ERCP with pancreatic stenting (experimental group) or without stenting (control group). Primary outcome measure was frequency of PEP, and secondary outcome measures included operative time, blood loss, postoperative recovery times, and other ERCP-associated morbidities. Results. Baseline age, sex, CBD etiology, concomitant medical/surgical conditions, cannulation difficulty, and ERCP success were comparable between the two groups (all P > 0.05). Compared to the control group, the experimental group had a significantly lower frequency of PEP (7.7% versus 17.7%, P < 0.05) and positive bile microbial culture (40.4% versus 62.7%, P < 0.05). However, the two groups were similar in operative time, blood loss, postoperative recovery times, and other ERCP-associated morbidities (all P > 0.05). Conclusions. Pancreatic stenting can reduce the occurrence of PEP and biliary sepsis in high-risk patients with complicating CBD disorders but does not increase other ERCP-associated morbidities. This trial is registered with the Chinese Clinical Trial Registry (registration identifier ChiCTR-OCH-14005134).

Exposure to Radiocontrast Agents Induces Pancreatic Inflammation by Activation of Nuclear Factor-κB, Calcium Signaling, and Calcineurin

BACKGROUND & AIMS

Radiocontrast agents are required for radiographic procedures, but these agents can injure tissues by unknown mechanisms. We investigated whether exposure of pancreatic tissues to radiocontrast agents during endoscopic retrograde cholangiopancreatography (ERCP) causes pancreatic inflammation, and studied the effects of these agents on human cell lines and in mice.

METHODS

We exposed mouse and human acinar cells to the radiocontrast agent iohexol (Omnipaque; GE Healthcare, Princeton, NJ) and measured intracellular release of Ca(2+), calcineurin activation (using a luciferase reporter), activation of nuclear factor-κB (NF-κB, using a luciferase reporter), and cell necrosis (via propidium iodide uptake). We infused the radiocontrast agent into the pancreatic ducts of wild-type mice (C57BL/6) to create a mouse model of post-ERCP pancreatitis; some mice were given intraperitoneal injections of the calcineurin inhibitor FK506 before and after infusion of the radiocontrast agent. CnAβ(-/-) mice also were used. This experiment also was performed in mice given infusions of adeno-associated virus 6-NF-κB-luciferase, to assess activation of this transcription factor in vivo.

RESULTS

Incubation of mouse and human acinar cells, but not HEK293 or COS7 cells, with iohexol led to a peak and then plateau in Ca(2+) signaling, along with activation of the transcription factors NF-κB and nuclear factor of activated T cells. Suppressing Ca(2+) signaling or calcineurin with BAPTA, cyclosporine A, or FK506 prevented activation of NF-κB and acinar cell injury. Calcineurin Aβ-deficient mice were protected against induction of pancreatic inflammation by iohexol. The calcineurin inhibitor FK506 prevented contrast-induced activation of NF-κB in pancreata of mice, this was observed by live imaging of mice given infusions of adeno-associated virus 6-NF-κB-luciferase.

CONCLUSIONS

Radiocontrast agents cause pancreatic inflammation in mice, via activation of NF-κB, Ca(2+) signaling, and calcineurin. Calcineurin inhibitors might be developed to prevent post-ERCP pancreatitis in patients.

Dynamic imaging of pancreatic nuclear factor κB (NF-κB) activation in live mice using adeno-associated virus (AAV) infusion and bioluminescence

Nuclear factor κB (NF-κB) is an important signaling molecule that plays a critical role in the development of acute pancreatitis. Current methods for examining NF-κB activation involve infection of an adenoviral NF-κB-luciferase reporter into cell lines or electrophoretic mobility shift assay of lysate. The use of adeno-associated viruses (AAVs) has proven to be an effective method of transfecting whole organs in live animals. We examined whether intrapancreatic duct infusion of AAV containing an NF-κB-luciferase reporter (AAV-NF-κB-luciferase) can reliably measure pancreatic NF-κB activation. We confirmed the infectivity of the AAV-NF-κB-luciferase reporter in HEK293 cells using a traditional luciferase readout. Mice were infused with AAV-NF-κB-luciferase 5 weeks before induction of pancreatitis (caerulein, 50 μg/kg). Unlike transgenic mice that globally express NF-κB-luciferase, AAV-infused mice showed a 15-fold increase in pancreas-specific NF-κB bioluminescence following 12 h of caerulein compared with baseline luminescence (p < 0.05). The specificity of the NF-κB-luciferase signal to the pancreas was confirmed by isolating the pancreas and adjacent organs and observing a predominant bioluminescent signal in the pancreas compared with liver, spleen, and stomach. A complementary mouse model of post-ERCP-pancreatitis also induced pancreatic NF-κB signals. Taken together these data provide the first demonstration that NF-κB activation can be examined in a live, dynamic fashion during pancreatic inflammation. We believe this technique offers a valuable tool to study real-time activation of NF-κB in vivo.

Indomethacin for preventing post-endoscopic retrograde cholangiopancreatography pancreatitis: A meta-analysis

AIM: To assess the effectiveness and safety of indomethacin in preventing post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP).

METHODS: Electronic searches were conducted to retrieve randomized controlled trials (RCTs) comparing indomethacin to placebo in the prevention of PEP from the PubMed, Embase, CBM, CNKI, WANFANG and VIP databases. Data collection and literature evaluation were performed by two reviewers independently. Review Manager 5.0 was used for statistical analysis.

RESULTS: A total of 11 RCTs involving 2718 patients were included. The meta-analysis showed that indomethacin could reduce the incidence of PEP (OR = 0.39, 95%CI: 0.30-0.52, P < 0.00001) and hyperamylasemia (OR = 0.50, 95%CI: 0.37-0.67, P < 0.00001).

CONCLUSION: Indomethacin is safe and effective in reducing the incidence of PEP and hyperamylasemia.

Bile acids induce pancreatic acinar cell injury and pancreatitis by activating calcineurin

Biliary pancreatitis is the leading cause of acute pancreatitis in both children and adults. A proposed mechanism is the reflux of bile into the pancreatic duct. Bile acid exposure causes pancreatic acinar cell injury through a sustained rise in cytosolic Ca(2+). Thus, it would be clinically relevant to know the targets of this aberrant Ca(2+) signal. We hypothesized that the Ca(2+)-activated phosphatase calcineurin is such a Ca(2+) target. To examine calcineurin activation, we infected primary acinar cells from mice with an adenovirus expressing the promoter for a downstream calcineurin effector, nuclear factor of activated T-cells (NFAT). The bile acid taurolithocholic acid-3-sulfate (TLCS) was primarily used to examine bile acid responses. TLCS caused calcineurin activation only at concentrations that cause acinar cell injury. The activation of calcineurin by TLCS was abolished by chelating intracellular Ca(2+). Pretreatment with 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid (acetoxymethyl ester) (BAPTA-AM) or the three specific calcineurin inhibitors FK506, cyclosporine A, or calcineurin inhibitory peptide prevented bile acid-induced acinar cell injury as measured by lactate dehydrogenase leakage and propidium iodide uptake. The calcineurin inhibitors reduced the intra-acinar activation of chymotrypsinogen within 30 min of TLCS administration, and they also prevented NF-κB activation. In vivo, mice that received FK506 or were deficient in the calcineurin isoform Aβ (CnAβ) subunit had reduced pancreatitis severity after infusion of TLCS or taurocholic acid into the pancreatic duct. In summary, we demonstrate that acinar cell calcineurin is activated in response to Ca(2+) generated by bile acid exposure, bile acid-induced pancreatic injury is dependent on calcineurin activation, and calcineurin inhibitors may provide an adjunctive therapy for biliary pancreatitis.

Advances in understanding the role of cytokines in the pathogenesis of acute pancreatitis after endoscopic retrograde cholangiopancreatography

Endoscopic retrograde cholangiopancreatography (ERCP) is an important tool for the diagnosis and treatment of pancreatobiliary disease. Acute pancreatitis (AP) is the most common complication of ERCP. The pathogenesis of post-ERCP AP has not been completely elucidated. Recent studies suggest that inflammatory cytokines play an important role in the evolution of AP from mild to severe form. Identification of specific proinflammatory markers that can rapidly and reliably predict the progression of post-ERCP pancreatitis has been a major focus of research. Attempts to block the inflammatory cascade have been carried out by using an anti-inflammatory cytokine in some clinical trials. In this article, we will review the recent advances in understanding the role of cytokines in the pathogenesis of post-ERCP AP.

Recent advances in the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis with NSAIDs

Acute pancreatitis is one of the most common complications of endoscopic retrograde cholangiopancreatography (ERCP) and often results in prolonged hospitalization and further intervention. Trials of many pharmacological therapies for post-ERCP pancreatitis (PEP) have yielded disappointing results. Non-steroidal anti-inflammatory drugs (NSAIDs) are potent inhibitors of prostaglandin synthesis, phospholipase A2 and neutrophil-endothelial interaction. Recently, prospective clinical trials evaluating NSAIDs in the prevention of PEP have yielded positive results, indicating their promising future in clinical use.

The prophylactic effect of somatostatin on post-therapeutic endoscopic retrograde cholangiopancreatography pancreatitis: a randomized, multicenter controlled trial

OBJECTIVES

Patients undergoing therapeutic endoscopic retrograde cholangiopancreatography (ERCP) are at a higher risk of developing post-ERCP pancreatitis than patients undergoing diagnostic ERCP. The aim of this study was to evaluate the effectiveness of somatostatin in preventing post-therapeutic ERCP pancreatitis.

METHODS

This placebo-controlled, double-blind, randomized study involved 391 patients in 3 hospitals who required therapeutic ERCP. Patients were assigned to receive either somatostatin or placebo. The incidence of pancreatitis and hyperamylasemia after performing ERCP was compared between the somatostatin and placebo groups.

RESULTS

Pancreatitis occurred in statistically significantly fewer ERCP patients who received somatostatin (7/193: 3.6%) than placebo (19/198: 9.6%; P = 0.02). With regard to the individual ERCP procedures, statistically significant reductions in post-ERCP pancreatitis were seen in patients treated with somatostatin who had stoneremoval (P = 0.04) and endoscopic papillary balloon dilation (P= 0.03). The incidence of hyperamylasemia was lower in the somatostatin group (7.8%) than in the placebo group (12.6%), although this difference was not statistically significant (P > 0.05).

CONCLUSIONS

A significantly lower incidence of post-ERCP pancreatitis occurred in patients who received somatostatin prophylaxis. This finding suggests that the administration of somatostatin is useful in preventing pancreatitis in patients undergoing therapeutic ERCP.

Assessment of 'nucleation time' as a predictor of cholelithiasis

INTRODUCTION

In the formation of gallstones, crystal nucleation is a key step, which is followed by precipitation and gradual growth of cholesterol crystals.

MATERIALS AND METHODS

A case-control study was carried out among 60 patients (30 patients, 14 males and 16 females, median age of 36 years, range 33-71 years, body mass index (BMI)=25.1+/-0.33 kg/m, who underwent laparoscopic cholecystectomy; 30 control individuals, 15 males and 15 females, median age of 38 years, range 33-70 years, BMI=24.5+/-0.23 kg/m, who underwent laparotomy and who had normal ultrasound scans of the gallbladder and no demonstrable stones). Bile aspirated from the common bile duct was ultrafiltered and anaerobically incubated at 37 degrees C. Incubated bile was examined daily by polarized light microscopy, for appearance of cholesterol crystals. Nucleation time (NT) of bile was assessed as the time taken for the first crystals to appear under polarized light microscopy.

RESULTS

Age and BMI of control individuals were not different to those of cases studied. The overall mean NT was significantly shorter in patients versus controls (mean NT+/-SEM: patients, 1.76+/-0.2 days; vs. controls, 12.74+/-0.4 days, P=0.001). Of control individuals, females demonstrated a shorter NT compared with males (mean NT+/-SEM: females, 11.4+/-0.36 days; vs. males, 14.1+/-0.46 days, P=0.006). In contrast, there was no sex difference in NT in patients (mean NT+/-SEM: females, 1.7+/-0.24 days; vs. males, 1.8+/-0.2 days, P=0.7).

CONCLUSION

NT in control individuals without gallstones was significantly prolonged compared with the NT in patients with established gallstone disease. Among the control individuals, females had a significantly shorter NT than males. Hence, the assessment of NT is predictor of cholelithiasis.

Review of idiopathic pancreatitis

Recent advances in understanding of pancreatitis and advances in technology have uncovered the veils of idiopathic pancreatitis to a point where a thorough history and judicious use of diagnostic techniques elucidate the cause in over 80% of cases. This review examines the multitude of etiologies of what were once labeled idiopathic pancreatitis and provides the current evidence on each. This review begins with a background review of the current epidemiology of idiopathic pancreatitis prior to discussion of various etiologies. Etiologies of medications, infections, toxins, autoimmune disorders, vascular causes, and anatomic and functional causes are explored in detail. We conclude with management of true idiopathic pancreatitis and a summary of the various etiologic agents. Throughout this review, areas of controversies are highlighted.

New precut sphincterotomy for endoscopic retrograde cholangiopancreatography in difficult biliary duct cannulation

AIM: To retrospectively investigate the effect and safety of various new type precut sphincterotomy techniques (VNTPST) in endoscopic retrograde cholangiopancreato-graphy (ERCP) due to difficult biliary duct cannulation (DBC).

METHODS: A plough-like pull-type sphincterotome (PLPTS) or improved short nose sphincterotome or improved needle knife was applied. VNTPST was carried out in 30 of 280 patients, whose biliary tract could not be exposed well or deep cannulation was difficult to perform during ERCP with traditional methods. Patients were followed up for short-term complications and the therapeutic effect of VNTPS was observed and compared with that of traditional endoscopic sphincterotomy (EST).

RESULTS: A total 280 patients underwent ERCP, of which 3 failed in operation because of pathological features in stomch or duodenum, 247 successfully underwent traditional ERCP (89.1%, 247/277), 30 failed (10.8%, 30/277). VNTPS technique succeeded in 24 (80%, 24/30) of 30 cases. The successful rate of deep biliary duct cannulation increased 8.6% (24/277), the total cannulation successful rate following precut was 97.7%. There was a significant difference between the two groups (97.7% vs 89.1%, χ² = 17.1, P < 0.01). The incidence of complications was 9.3% (26/277) for traditional ERCP group and 13.3% (4/30) for VNTPS technique group. Guideline tip was broken in pancreatic duct (KPDGP) of one patient, and there was no pancreatitis, slight or moderate bleeding postoperatively occurred in 2 patients, 1 patient had bleeding during operation (PDWN). There were no differences between VNTPS technique group and traditional ERCP (TRERCP) group (13.3% vs 9.3%, χ² = 0.478, P > 0.05).

CONCLUSION: VNTPS procedure and Deng’s precut are highly effective methods to get biliary access during ERCP with DBC. With skillful techniques, it can increase the successful rate for deep cannulation of biliary duct and decrease complications. VNTPS technique, especially Deng’s precut is as effective and safe as EST. This technique can be well performed in hospitals without particular equipments.