N-acetylcysteine does not prevent post-endoscopic retrograde cholangiopancreatography hyperamylasemia and acute pancreatitis

Incidence, severity, and mortality of post-ERCP pancreatitis: an updated systematic review and meta-analysis of 145 randomized controlled trials

BACKGROUND AND AIMS

The incidence, severity, and mortality of post-ERCP pancreatitis (PEP) largely remain unknown with changing trends in ERCP use, indication, and techniques. We sought to determine the incidence, severity, and mortality of PEP in consecutive and high-risk patients based on a systemic review and meta-analysis of patients in placebo and no-stent arms of randomized control trials (RCTs).

METHODS

The MEDLINE, Embase, and Cochrane databases were searched from the inception of each database to June 2022 to identify full-text RCTs evaluating PEP prophylaxes. The incidence, severity, and mortality of PEP from the placebo or no-stent arms of RCTs were recorded for consecutive and high-risk patients. A random-effects meta-analysis for a proportions model was used to calculate PEP incidence, severity, and mortality.

RESULTS

One hundred forty-five RCTs were found with 19,038 patients in the placebo or no-stent arms. The overall cumulative incidence of PEP was 10.2% (95% confidence interval [CI], 9.3-11.3), predominantly among the academic centers conducting such RCTs. The cumulative incidences of severe PEP and mortality were .5% (95% CI, .3-.7) and .2% (95% CI, .08-.3), respectively, across 91 RCTs with 14,441 patients. The cumulative incidences of PEP and severe PEP were 14.1% (95% CI, 11.5-17.2) and .8% (95% CI, .4-1.6), respectively, with a mortality rate of .2% (95% CI, 0-.3) across 35 RCTs with 3733 patients at high risk of PEP. The overall trend for the incidence of PEP among patients randomized to placebo or no-stent arms of RCTs has remained unchanged from 1977 to 2022 (P = .48).

CONCLUSIONS

The overall incidence of PEP is 10.2% but is 14.1% among high-risk patients based on this systematic review of placebo or no-stent arms of 145 RCTs; this rate has not changed between 1977 and 2022. Severe PEP and mortality from PEP are relatively uncommon.

ORAL N-ACETYL CYSTEINE VERSUS RECTAL INDOMETHACIN FOR PREVENTION OF POST ERCP PANCREATITIS: A MULTICENTER MULTINATIONAL RANDOMIZED CONTROLLED TRIAL

BACKGROUND

This multicenter multinational RCT designed to compare the efficacy of suppository indomethacin and NAC for prevention of PEP.

METHODS

During a 6-month period, all of the ERCP cases in seven referral centers were randomly assigned to receive either 1200 mg oral NAC, indomethacin suppository 100 mg, 1200 mg oral NAC plus indomethacin suppository 100 mg or placebo 2 hours before ERCP. The primary outcomes were the rate and severity of any PEP.

RESULTS

A total of 432 patients included (41.4% male). They were originally citizens of 6 countries (60.87% Caucasian). They were randomly allocated to receive either NAC (group A, 84 cases), rectal indomethacin (group B, 138 cases), NAC + rectal indomethacin (group C, 115 cases) or placebo (group D, 95 cases). The rate of PEP in groups A, B and C in comparison with placebo were 10.7%, 17.4%, 7.8% vs 20% (P=0.08, 0.614 & 0.01 respectively). The NNT for NAC, indomethacin and NAC + indomethacin was 11, 38 and 8 respectively.

CONCLUSION

Oral NAC is more effective than rectal indomethacin when compared to placebo for prevention of PEP and the combination of NAC and Indomethacin had the lowest incidence of PEP and may have synergistic effect in preventing of PEP (IRCT20201222049798N1; 29/12/2020).

A simple nomogram for early postoperative risk prediction of clinically relevant pancreatic fistula after pancreatoduodenectomy

PURPOSE

Postoperative pancreatic fistulae (POPF) present a serious and life-threatening complication after pancreatic head resections (PD). Therefore, reliable risk stratification to identify those at risk is urgently needed. The aim of this study was to identify postoperative laboratory parameters for the prediction of POPF in the early postoperative period.

METHODS

One hundred eighty-two patients who underwent PD from 2012 until 2017 were retrospectively analyzed. Multivariate logistic regression was performed using the GLM (general linear model) method for model building. Two nomograms were created based on the GLM models of postoperative day one and postoperative day one to five. A cohort of 48 patients operated between 2018 and 2019 served as internal validation.

RESULTS

Clinically relevant pancreatic fistulae (CR-POPF) were present in 16% (n = 29) of patients. Patients with CR-POPF experienced significantly more insufficiencies of gastroenterostomies, delayed gastric emptying, and more extraluminal bleeding than patients without CR-POPF. Multivariate analysis revealed multiple postoperative predictive models, the best one including ASA, main pancreatic duct diameter, operation time, and serum lipase as well as leucocytes on day one. This model was able to predict CR-POPF with an accuracy of 90% and an AUC of 0.903. Two nomograms were created for easier use.

CONCLUSION

Clinically relevant fistula can be predicted using simple laboratory and clinical parameters. Not serum amylase, but serum lipase is an independent predictor of CR-POPF. Our simple nomograms may help in the identification of patients for early postoperative interventions.

Cysteine/Glutathione Deficiency: A Significant and Treatable Corollary of Disease

Glutathione (GSH) deficiency may play a pivotal role in a variety of apparently unrelated clinical conditions and diseases. Orally administered N-acetylcysteine (NAC), which replenishes the cysteine required for GSH synthesis, has been tested in a large number of randomized placebo-controlled trials involving these diseases and conditions. This chapter focused on developing a base of evidence suggesting that NAC administration improves disease by increasing cysteine and/or GSH in a variety of diseases, thereby implying a significant role for GSH deficiency in the clinical basis of many diseases. To develop this base of evidence, we systematically selected studies which considered the hypothesis that the therapeutic efficacy for NAC is an indication that cysteine and/or GSH deficiency is a pathophysiological part of the diseases studied. In this manner we focus this chapter on explaining the biological mechanisms of NAC therapy in a wide variety of disorders and demonstrate its ubiquitous role in improving disease that involves disrupted GSH and/or cysteine metabolism.

Dynamic thiol/disulphide homeostasis in acute pancreatitis

BACKGROUND/AIMS

The dynamic thiol/disulfide homeostasis plays pivotal roles in many physiological mechanisms in an organism. We aimed to investigate whether dynamic thiol/disulfide homeostasis changes among patients with acute pancreatitis.

MATERIALS AND METHODS

This prospective trial contained 45 patients with acute pancreatitis and 45 sex-and age-matched healthy volunteers as control group. Thiol/disulfide homeostasis parameters were measured by a novel and automated assay, and detected results were compared between the two groups.

RESULTS

Disulfide/total thiol percent ratio and disulfide/native thiol percent ratios were significantly higher in acute pancreatitis group; besides the native thiol, total thiol levels and native thiol/total thiol percent ratios were significantly lower (for all p < 0.001).

CONCLUSION

The thiol/disulfide homeostasis is impaired in acute pancreatitis with a shift toward the oxidative status, and this deficiency might be a pathogenic factor in acute pancreatitis. The correction of this thiol/disulfide imbalance may be a new target in the management of acute pancreatitis.

The "Scope" of Post-ERCP Pancreatitis

Pancreatitis is the most common adverse event of endoscopic retrograde cholangiopancreatography, with the potential for clinically significant morbidity and mortality. Several patient and procedural risk factors have been identified that increase the risk of post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP). Considerable research efforts have identified several pharmacologic and procedural interventions that can drastically affect the incidence of PEP. This review article addresses the underlying mechanisms at play for the development of PEP, identifying patient and procedural risk factors and meaningful use of risk-stratification information, and details current interventions aimed at reducing the risk of this complication.

Synthetic Triterpenoid RTA dh404 (CDDO-dhTFEA) Ameliorates Acute Pancreatitis

OBJECTIVES

Nuclear factor-erythroid-2-related factor (Nrf2) is a ubiquitous transcriptional factor that regulates expression of cellular antioxidant and detoxifying molecules. This study was undertaken to test the hypothesis that administration of the Nrf2 activator (dh404) may attenuate acute pancreatitis.

METHODS

Rats were treated with dh404 (1 mg/kg) 24 hours before induction of pancreatitis and for 3 days thereafter. Pancreatitis was induced with L-arginine (600 mg/100 g) or cerulein (40 μg/kg). Pancreases were processed for histology and malondialdehyde, whereas serum was analyzed for amylase. Islet extracted human pancreatic tissue from organ donors were used for in vitro studies. The tissues were incubated with dh404 at 0, 250, and 500 nM for 30 minutes, 60 minutes, 12 hours, and 24 hours. Nuclear factor-erythroid-2-related factor nuclear translocation and expression of Nrf2's target genes and inflammatory mediators were determined.

RESULTS

The dh404-treated rat pancreases demonstrated significantly less infiltration of inflammatory cells, destruction of acinar architecture, perilobar edema, and necrosis. Serum amylase and pancreatic malondialdehyde in the dh404-treated rats were significantly lower. dh404-treated human pancreatic tissue showed a significantly higher expression of antioxidant enzymes, lower expression of inflammatory mediators, and greater viability against oxidative stress.

CONCLUSION

Administration of dh404 attenuates acute pancreatitis by lowering oxidative stress and reducing proinflammatory mediators.

Antioxidant and Anti-Inflammatory Effects of Coenzyme Q10 on L-Arginine-Induced Acute Pancreatitis in Rat

This study was aimed at evaluating the protective effect of coenzyme Q10 on L-arginine-induced acute pancreatitis in rats regarding biomarkers and morphologic changes. Thirty-two male Sprague-Dawley rats were divided into 4 equal groups. Control group received intraperitoneal normal saline, while in sham and experimental groups 1 and 2 pancreatitis was induced with L-arginine. E1 and E2 groups were treated with a single dose of 100 and 200 mg/kg Q10, respectively. Serum lipase and amylase, along with pancreas IL-10, IL-1β, and TNF-α, were measured. For evaluation of oxidative stress, pancreatic superoxide dismutase (SOD), glutathione (GSH), malondialdehyde (MDA), and myeloperoxidase (MPO) were assessed. Histopathological examination for morphologic investigation was conducted. Serum amylase and lipase, as well as TNF-α and IL-1β cytokines, reverted with administration of Q10 in consistence with dosage. In contrast, Q10 assisted in boosting of IL-10 with higher dosage (200 mg/kg). A similar pattern for oxidative stress markers was noticed. Both MDA and MPO levels declined with increased dosage, contrary to elevation of SOD and GSH. Histopathology was in favor of protective effects of Q10. Our findings proved the amelioration of pancreatic injury by Q10, which suggest the anti-inflammatory and antioxidant property of Q10 and its potential therapeutic role.

Antioxidant therapy in acute, chronic and post-endoscopic retrograde cholangiopancreatography pancreatitis: An updated systematic review and meta-analysis

AIM: To investigate the efficacy and adverse effects of antioxidant therapy in acute pancreatitis (AP), chronic pancreatitis (CP) and post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP).

METHODS: PubMed, Scopus, Google Scholar, Cochrane library database, and Evidence-based medicine/clinical trials published before August 2014 were searched. Clinical and laboratory outcomes of randomized trials of antioxidant therapy in patients with AP, CP and PEP were included. The methodological quality of the trials was assessed by the Jadad score based on the description of randomization, blinding, and dropouts (withdrawals). The results of the studies were pooled and meta-analyzed to provide estimates of the efficacy of antioxidant therapy.

RESULTS: Thirty four trials out of 1069 potentially relevant studies with data for 4898 patients were eligible for inclusion. Antioxidant therapy significantly reduced the length of hospital stay in AP patients {mean difference -2.59 d (95%CI: -4.25-(-0.93)], P = 0.002}. Although, antioxidant therapy had no significant effect on serum C reactive protein (CRP) after 5-7 d in AP patients [mean difference -9.57 (95%CI: -40.61-21.48, P = 0.55], it significantly reduced serum CRP after 10 d {mean difference -45.16 [95%CI: -89.99-(-0.33)], P = 0.048}. In addition, antioxidant therapy had no significant effect on CP-induced pain [mean difference -2.13 (95%CI: -5.87-1.6), P = 0.26]. Antioxidant therapy had no significant effects on the incidence of all types of PEP [mean difference 1.05 (95%CI: 0.74-1.5), P = 0.78], severe PEP [mean difference 0.92 (95%CI: 0.43-1.97), P = 0.83], moderate PEP [mean difference 0.82 (95%CI: 0.54-1.23), P = 0.33], and mild PEP [mean difference 1.33 (95%CI: 0.99-1.78), P = 0.06]. Furthermore, while antioxidant therapy had no significant effect on serum amylase after less than 8 h sampling [mean difference -20.61 (95%CI: -143.61-102.39), P = 0.74], it significantly reduced serum amylase close to 24-h sampling {mean difference -16.13 [95%CI: -22.98-(-9.28)], P < 0.0001}.

CONCLUSION: While there is some evidence to support antioxidant therapy in AP, its effect on CP and PEP is still controversial.

Redox signaling in acute pancreatitis

Acute pancreatitis is an inflammatory process of the pancreatic gland that eventually may lead to a severe systemic inflammatory response. A key event in pancreatic damage is the intracellular activation of NF-κB and zymogens, involving also calcium, cathepsins, pH disorders, autophagy, and cell death, particularly necrosis. This review focuses on the new role of redox signaling in acute pancreatitis. Oxidative stress and redox status are involved in the onset of acute pancreatitis and also in the development of the systemic inflammatory response, being glutathione depletion, xanthine oxidase activation, and thiol oxidation in proteins critical features of the disease in the pancreas. On the other hand, the release of extracellular hemoglobin into the circulation from the ascitic fluid in severe necrotizing pancreatitis enhances lipid peroxidation in plasma and the inflammatory infiltrate into the lung and up-regulates the HIF-VEGF pathway, contributing to the systemic inflammatory response. Therefore, redox signaling and oxidative stress contribute to the local and systemic inflammatory response during acute pancreatitis.

Incidence, severity, and mortality of post-ERCP pancreatitis: a systematic review by using randomized, controlled trials

BACKGROUND

Data regarding the incidence and severity of post-ERCP pancreatitis (PEP) are primarily from nonrandomized studies.

OBJECTIVE

To determine the incidence, severity, and mortality of PEP from a systematic review of the placebo or no-stent arms of randomized, controlled trials (RCTs).

DESIGN

MEDLINE, EMBASE, and Cochrane databases were searched to identify RCTs evaluating the efficacy of drugs and/or pancreatic stents to prevent PEP.

SETTING

Systematic review of patients enrolled in RCTs evaluating agents for PEP prophylaxis.

PATIENTS

Patients in the placebo or no-stent arms of the RCTs

INTERVENTION

ERCP.

MAIN OUTCOME MEASUREMENTS

Incidence, severity, and mortality of PEP.

RESULTS

There were 108 RCTs with 13,296 patients in the placebo or no-stent arms. Overall, the PEP incidence was 9.7% and the mortality rate was 0.7%. Severity of PEP was reported for 8857 patients: 5.7%, 2.6%, and 0.5% of cases were mild, moderate, and severe, respectively. The incidence of PEP in 2345 high-risk patients was 14.7% and the severity of PEP was mild, moderate, and severe in 8.6%, 3.9%, and 0.8%, respectively, with a 0.2% mortality rate. The incidence of PEP was 13% in North American RCTs compared with 8.4% in European and 9.9% in Asian RCTs. ERCPs conducted before and after 2000 had a PEP incidence of 7.7% and 10%, respectively.

LIMITATIONS

Difference in PEP risk among patients in the included RCTs.

CONCLUSION

The incidence of PEP and severe PEP is similar in high-risk patients and the overall cohort. Discrepancies in the incidence of PEP across geographic regions require further study.

Free radicals and acute pancreatitis: much ado about … something

There is a convincing body of evidence that oxidative stress is involved in the pathogenesis of acute pancreatitis. The effects of different radical scavengers suggested that reactive oxygen metabolites are generated at very early stage of disease and contribute to amplify the pancreatic damage. Oxidative stress is also involved in the progression of the disease from a local damage to a systemic organ failure. However, therapeutic use of antioxidants failed to clearly show a clinical benefit in different trials. Therefore, although antioxidants alone seem to be not enough for the treatment of severe acute pancreatitis, future combined therapeutic strategies should include antioxidants in its composition.

Antioxidant supplementation for the prevention of post-endoscopic retrograde cholangiopancreatography pancreatitis: a meta-analysis of randomized controlled trials

Background

Acute pancreatitis remains the most common major complication of endoscopic retrograde cholangiopancreatography (ERCP). The pathogenesis of post-ERCP acute pancreatitis may be mediated by oxygen-derived free radicals, which could be ameliorated by antioxidants. Antioxidant supplementation may potentially prevent post-ERCP pancreatitis. We performed a meta-analysis of randomized controlled trials to evaluate the effect of prophylactic antioxidant supplementation compared with control on the prevention of post-ERCP pancreatitis.

Methods

PubMed and Embase databases were searched to identify relevant trials. A standardized Excel file was used to extract data by two independent authors. Results were expressed as risk ratio (RR) with accompanying 95% confidence interval (CI). The meta-analysis was performed with the fixed-effects model or random-effects model according to heterogeneity.

Results

Eleven studies involving 3,010 patients met our inclusion criteria. Antioxidant supplementation did not significantly decrease the incidence of post-ERCP pancreatitis (RR, 0.92; 95% CI, 0.65-1.32; P = 0.665). There was also no statistical difference in the severity grades between the antioxidant group and control group.

Conclusions

Based on current evidence, antioxidant supplementation shows no beneficial effect on the incidence and the severity of post-ERCP pancreatitis; thus, there is currently a lack of evidence to support using antioxidants for the prevention of post-ERCP pancreatitis.

Role of Oxidative Stress in the Pathogenesis of Pancreatitis: Effect of Antioxidant Therapy

Oxidative stress plays an important role in the pathogenesis of acute pancreatitis. The exact pathogenesis of pancreatitis remains unknown but several mechanisms related to oxidative and inflammatory stress are implicated. It is reasonable to surmise that antioxidants would play a protective role in ameliorating the deleterious effects of pancreatitis. We have a wealth of data from animal models that reveal a positive correlation between antioxidant drugs and improved outcomes in experimental pancreatitis. Human clinical trials with antioxidants however, have disclosed conflicting results. We review the existing pathogenesis of pancreatitis related to oxidative stress and provide of a review of current trials with antioxidant therapy.

Evaluation of N-acetyl Cysteine for the Prevention of Post-endoscopic Retrograde Cholangiopancreatography Pancreatitis: A Prospective Double Blind Randomized Pilot Study

BACKGROUND

Acute pancreatitis is the most common serious complication of endoscopic retrograde cholangiopancreatography (ERCP) that can occasionally be fatal. Multiple drugs have been examined for the prevention of this side effect, with generally uncertain results. This study is an effort to prevent this complication by the use of oral N-acetyl cysteine (NAC).

METHODS

A total of 100 patients who were candidates for ERCP were divided randomly into two groups. In the NAC (N) group, patients received 1200 mg NAC with 150 cc water orally 2 h before ERCP. In the placebo (P) group, 150 cc water was prescribed as a placebo. We measured serum amylase and lipase levels before and 24 h after ERCP. The prevalence of pancreatitis and duration of admission in each group were determined and compared.

RESULTS

In group N there were 5 (10%) cases of pancreatitis, whereas in group P there were 14 (28%) cases, which was significant (risk reduction ratio: 2.8; p=0.02).The average admission time was 1.16±0.55 days in group N and 1.18±0.44 days in group P, which was not significant.

CONCLUSION

There were significant differences in the prevalence of acute pancreatitis between the two groups. In addition, the number of need to treat (NNT) consisted of five cases for NAC. With regards to the above results and the safety profile of NAC, it could be used as a therapeutic agent for the prevention of post-ERCP pancreatitis. We recommend that the results of this study be verified by additional clinical trials.

Experimental and clinical evidence of antioxidant therapy in acute pancreatitis

Oxidative stress has been shown to play an important role in the pathogenesis of acute pancreatitis (AP). Antioxidants, alone or in combination with conventional therapy, should improve oxidative-stress-induced organ damage and therefore accelerate the rate of recovery. In recent years, substantial amounts of data about the efficiency of antioxidants against oxidative damage have been obtained from experiments with rodents. Some of these antioxidants have been found beneficial in the treatment of AP in humans; however, at present there is insufficient clinical data to support the benefits of antioxidants, alone or in combination with conventional therapy, in the management of AP in humans. Conflicting results obtained from experimental animals and humans may represent distinct pathophysiological mechanisms mediating tissue injury in different species. Further detailed studies should be done to clarify the exact mechanisms of tissue injury in human AP. Herein I tried to review the existing experimental and clinical studies on AP in order to determine the efficiency of antioxidants. The use of antioxidant enriched nutrition is a potential direction of clinical research in AP given the lack of clues about the efficiency and safety of antioxidant usage in patients with AP.

N-acetylcysteine for sepsis and systemic inflammatory response in adults

BACKGROUND

Death is common in systemic inflammatory response syndrome (SIRS) or sepsis-induced multisystem organ failure and it has been thought that antioxidants such as N-acetylcysteine could be beneficial.

OBJECTIVES

We assessed the clinical effectiveness of intravenous N-acetylcysteine for the treatment of patients with SIRS or sepsis.

SEARCH METHODS

We searched the following databases: Cochrane Central Register of Clinical Trials (CENTRAL) (The Cochrane Library 2011, Issue 12); MEDLINE (January 1950 to January 2012); EMBASE (January 1980 to January 2012); CINAHL (1982 to January 2012); the NHS Trusts Clinical Trials Register and Current Controlled Trials (www.controlled-trials.com); LILACS; KoreaMED; MEDCARIB; INDMED; PANTELEIMON; Ingenta; ISI Web of Knowledge and the National Trials Register to identify all relevant randomized controlled trials available for review.

SELECTION CRITERIA

We included only randomized controlled trials (RCTs) in the meta-analysis.

DATA COLLECTION AND ANALYSIS

We independently performed study selection, quality assessment and data extraction. We estimated risk ratios (RR) for dichotomous outcomes. We measured statistical heterogeneity using the I(2) statistic.

MAIN RESULTS

We included 41 fully published studies (2768 patients). Mortality was similar in the N-acetylcysteine group and the placebo group (RR 1.06, 95% CI 0.79 to 1.42; I(2) = 0%). Neither did N-acetylcysteine show any significant effect on length of stay, duration of mechanical ventilation or incidence of new organ failure. Early application of N-acetylcysteine to prevent the development of an oxidato-inflammatory response did not affect the outcome, nor did late application that is after 24 hours of developing symptoms. Late application was associated with cardiovascular instability.

AUTHORS' CONCLUSIONS

Overall, this meta-analysis puts doubt on the safety and utility of intravenous N-acetylcysteine as an adjuvant therapy in SIRS and sepsis. At best, N-acetylcysteine is ineffective in reducing mortality and complications in this patient population. At worst, it can be harmful, especially when administered later than 24 hours after the onset of symptoms, by causing cardiovascular depression. Unless future RCTs provide evidence of treatment effect, clinicians should not routinely use intravenous N-acetylcysteine in SIRS or sepsis and academics should not promote its use.

Hydrogen-rich saline reduces the oxidative stress and relieves the severity of trauma-induced acute pancreatitis in rats

BACKGROUND

Currently, little evidence exists to support whether the therapeutic approaches for treating ordinary acute pancreatitis (AP) are effective in trauma-induced pancreatitis. Hydrogen-rich (H2) saline is an antioxidant treatment capable of ameliorating the severity of L-arginine-induced AP. In this study, we attempted to validate its protective role against traumatic pancreatitis (TP).

METHODS

A previously established experimental rat model of TP was generated by controlled delivery of high pressure air impact. The protective effects of H2 saline against TP were evaluated in this model system by measuring survival rate and determining changes in histopathology, plasma enzymes, cytokines, and oxidative stress-associated molecules.

RESULTS

Intraperitoneal administration of H2-rich saline produced a pronounced protection against TP in rats. Significant improvements were observed in survival rate and histopathological findings. In addition, plasma cytokines concentrations were reduced in H2 saline-treated TP rats. Although no marked inhibitory effect on plasma amylase and lipase activities was observed, H2 saline caused considerable suppression of pancreatic malondialdehyde level and recruitment of endogenous pancreatic antioxidants, such as glutathione and superoxide dismutase.

CONCLUSIONS

H2-rich saline has beneficial effects on TP, presumably because of its detoxification activities against excessive reactive oxygen species. Our findings highlight the potential of H2-rich saline as a therapeutic agent of trauma-induced AP.

Prevention of Post-ERCP Pancreatitis

Pancreatitis is the most common complication of ERCP. It can be associated with substantial morbidity. Hence, the minimization of both the incidence and severity of post-ERCP pancreatitis is paramount. Considerable efforts have been made to identify factors that may be associated with an increased risk of this complication. In addition, both procedure- and pharmacological-related interventions have been proposed that may prevent this complication. This paper outlines these interventions and presents the evidence to support their use in the prevention of post-ERCP pancreatitis.

Endoscopic retrograde cholangiopancreatography associated pancreatitis: A 15-year review

The aim of this article is to review the literature regarding post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis. We searched for and evaluated all articles describing the diagnosis, epidemiology, pathophysiology, morbidity, mortality and prevention of post-ERCP pancreatitis (PEP) in adult patients using the PubMed database. Search terms included endoscopic retrograde cholangiopancreatography, pancreatitis, ampulla of vater, endoscopic sphincterotomy, balloon dilatation, cholangiography, adverse events, standards and utilization. We limited our review of articles to those published between January 1, 1994 and August 15, 2009 regarding human adults and written in the English language. Publications from the reference sections were reviewed and included if they were salient and fell into the time period of interest. Between the dates queried, seventeen large (> 500 patients) prospective and four large retrospective trials were conducted. PEP occurred in 1%-15% in the prospective trials and in 1%-4% in the retrospective trials. PEP was also reduced with pancreatic duct stent placement and outcomes were improved with endoscopic sphincterotomy compared to balloon sphincter dilation in the setting of choledocholithiasis. Approximately 34 pharmacologic agents have been evaluated for the prevention of PEP over the last fifteen years in 63 trials. Although 22 of 63 trials published during our period of review suggested a reduction in PEP, no pharmacologic therapy has been widely accepted in clinical use in decreasing the development of PEP. In conclusion, PEP is a well-recognized complication of ERCP. Medical treatment for prevention has been disappointing. Proper patient selection and pancreatic duct stenting have been shown to reduce the complication rate in randomized clinical trials.

Post-ERCP pancreatitis

Pancreatitis remains the most common severe complication of endoscopic retrograde cholangiopancreatography (ERCP). Detailed information about the findings of previous studies concerning post-ERCP pancreatitis has not been utilized sufficiently. The purpose of the present article was to present guidelines for the diagnostic criteria of post-ERCP pancreatitis, and its incidence, risk factors, and prophylactic procedures that are supported by evidence. To achieve this purpose, a critical examination was made of the articles on post-ERCP pancreatitis, based on the data obtained by research studies published up to 2009. At present, there are no standardized diagnostic criteria for post-ERCP pancreatitis. It is appropriate that post-ERCP pancreatitis is defined as acute pancreatitis that has developed following ERCP, and its diagnosis and severity assessment should be made according to the diagnostic criteria and severity assessment of the Japanese Ministry of Health, Labour and Welfare. The incidence of acute pancreatitis associated with diagnostic and therapeutic ERCP is 0.4-1.5 and 1.6-5.4%, respectively. Endoscopic papillary balloon dilation is associated with a high risk of acute pancreatitis compared with endoscopic sphincterotomy. It was made clear that important risk factors include dysfunction of the Oddi sphincter, being of the female sex, past history of post-ERCP pancreatitis, and performance of pancreaticography. Temporary prophylactic placement of pancreatic stents in the high-risk group is useful for the prevention of post-ERCP pancreatitis [odds ratio (OR) 3.2, 95% confidence interval (CI) 1.6-6.4, number needed to treat (NNT) 10]. Use of nonsteroidal anti-inflammatory drugs (NSAIDs) is associated with a reduction in the development of post-ERCP pancreatitis (OR 0.46, 95% CI 0.32-0.65). Single rectal administration of NSAIDs is useful for the prevention of post-ERCP pancreatitis [relative risk (RR) 0.36, 95% CI 0.22-0.60, NNT 15] and decreases the development of pancreatitis in both the low-risk group (RR 0.29, 95% CI 0.12-0.71) and the high-risk group (RR 0.40, 95% CI 0.23-0.72) of post-ERCP pancreatitis. As for somatostatin, a bolus injection may be most useful compared with short- or long-term infusion (OR 0.271, 95% CI 0.138-0.536, risk difference 8.2%, 95% CI 4.4-12.0%). The usefulness of gabexate mesilate was not apparent in any of the following conditions: acute pancreatitis (control 5.7 vs. 4.8% for gabexate mesilate), hyperamylasemia (40.6 vs. 36.9%), and abdominal pain (1.7 vs. 8.9%). Formulation of diagnostic criteria for post-ERCP pancreatitis is needed. Temporary prophylactic placement of pancreatic stents in the high-risk group offers the most promise as a means of preventing post-ERCP pancreatitis. As for pharmacological attempts, there are high expectations concerning NSAIDs because they are excellent in terms of cost-effectiveness, ease of use, and safety. There was no evidence of effective prophylaxis with the use of protease inhibitors, especially gabexate mesilate.

Antioxidant therapy in the management of acute, chronic and post-ERCP pancreatitis: A systematic review

We systematically reviewed the clinical trials which recruited antioxidants in the therapy of pancreatitis and evaluated whether antioxidants improve the outcome of patients with pancreatitis. Electronic bibliographic databases were searched for any studies which investigated the use of antioxidants in the management of acute pancreatitis (AP) or chronic pancreatitis (CP) and in the prevention of post-endoscopic retrograde cholangio-pancreatography (post-ERCP) pancreatitis (PEP) up to February 2009. Twenty-two randomized, placebo-controlled, clinical trials met our criteria and were included in the review. Except for a cocktail of antioxidants which showed improvement in outcomes in three different clinical trials, the results of the administration of other antioxidants in both AP and CP clinical trials were incongruent and heterogeneous. Furthermore, antioxidant therapy including allopurinol and N-acetylcysteine failed to prevent the onset of PEP in almost all trials. In conclusion, the present data do not support a benefit of antioxidant therapy alone or in combination with conventional therapy in the management of AP, CP or PEP. Further double blind, randomized, placebo-controlled clinical trials with large sample size need to be conducted.

Role of oxidative stress in pancreatic inflammation

Reactive oxygen and reactive nitrogen species (ROS/RNS) have been implicated in the pathogenesis of acute and chronic pancreatitis. Clinical and basic science studies have indicated that ROS/RNS formation processes are intimately linked to the development of the inflammatory disorders. The detrimental effects of highly reactive ROS/RNS are mediated by their direct actions on biomolecules (lipids, proteins, and nucleic acids) and activation of proinflammatory signal cascades, which subsequently lead to activation of immune responses. The present article summarizes the possible sources of ROS/RNS formation and the detailed signaling cascades implicated in the pathogenesis of pancreatic inflammation, as observed in acute and chronic pancreatitis. A therapeutic ROS/RNS-scavenging strategy has been advocated for decades; however, clinical studies examining such approaches have been inconsistent in their results. Emerging evidence indicates that pancreatitis-inducing ROS/RNS generation may be attenuated by targeting ROS/RNS-generating enzymes and upstream mediators.

Effects in the control of edema of the papilla of Vater by epinephrine saline irrigation after endoscopic retrograde cholangiopancreatography in an endoscopy center in Japan, 2003 to 2007: exploratory retrospective analysis to evaluate the characteristics of eligible patients with a focus on serum amylase levels

OBJECTIVE

To evaluate the effects of localized irrigation with epinephrine saline after endoscopic retrograde cholangiopancreatography (ERCP).

PATIENTS AND METHODS

One hundred and fourteen patients who underwent ERCP in our institute were treated with or without irrigation using epinephrine diluted in saline after ERCP to prevent post-ERCP pancreatitis. The serum amylase levels, white blood cell counts, and urine amylase levels were measured at 24 and 48 hours after ERCP.

RESULTS

The treatment resulted in improvements in all items. A univariate analysis of the explanatory variables between the treatment and untreated groups revealed the treatment to be effective, but not statistically significant. Gender and cannulation of the pancreatic duct were the only variables with significant partial regression coefficients in the multiple regression model with all explanatory variables (p=0.045). When a stratified analysis was conducted using gender as a moderator variable, the treatment became a significant preventive factor (p=0.038), and cannulation of the pancreatic duct was a significant risk factor (p=0.027) in female patients.

CONCLUSION

We suggest that irrigating with epinephrine saline into the papilla may be effective for preventing pancreatitis in female patients who received ERCP with cannulation of their pancreatic duct.

Pharmacological approach to acute pancreatitis

The aim of the present review is to summarize the current knowledge regarding pharmacological prevention and treatment of acute pancreatitis (AP) based on experimental animal models and clinical trials. Somatostatin (SS) and octreotide inhibit the exocrine production of pancreatic enzymes and may be useful as prophylaxis against Post Endoscopic retrograde cholangiopancreatography Pancreatitis (PEP). The protease inhibitor Gabexate mesilate (GM) is used routinely as treatment to AP in some countries, but randomized clinical trials and a meta-analysis do not support this practice. Nitroglycerin (NGL) is a nitrogen oxide (NO) donor, which relaxes the sphincter of Oddi. Studies show conflicting results when applied prior to ERCP and a large multicenter randomized study is warranted. Steroids administered as prophylaxis against PEP has been validated without effect in several randomized trials. The non-steroidal anti-inflammatory drugs (NSAID) indomethacin and diclofenac have in randomized studies showed potential as prophylaxis against PEP. Interleukin 10 (IL-10) is a cytokine with anti-inflammatory properties but two trials testing IL-10 as prophylaxis to PEP have returned conflicting results. Antibodies against tumor necrosis factor-alpha (TNF-α) have a potential as rescue therapy but no clinical trials are currently being conducted. The antibiotics beta-lactams and quinolones reduce mortality when necrosis is present in pancreas and may also reduce incidence of infected necrosis. Evidence based pharmacological treatment of AP is limited and studies on the effect of potent anti-inflammatory drugs are warranted.

Allopurinol to prevent pancreatitis after endoscopic retrograde cholangiopancreatography: a randomized placebo-controlled trial

BACKGROUND & AIMS

Endoscopic retrograde cholangiopancreatography (ERCP) is associated with a risk of pancreatitis (PEP). Animal studies suggest that (single-dose) allopurinol (xanthine oxidase inhibitor with high oral bioavailability and long-lasting active metabolites) may reduce this risk; human study results are conflicting. The aim of this study was to determine if allopurinol decreases the rate of PEP.

METHODS

Patients referred for ERCP to 9 endoscopists at 2 tertiary centers were randomized to receive either allopurinol 300 mg or identical placebo orally 60 minutes before ERCP, stratified according to high-risk ERCP (manometry or pancreatic therapy). The primary outcome (PEP) was adjudicated blindly; pancreatitis was defined according to the Cotton consensus, and evaluated at 48 hours and 30 days. Secondary outcomes included severe PEP, length of stay, and mortality (nil). The trial was terminated after the blinded (midpoint) interim analysis, as recommended by the independent data and safety monitoring committee.

RESULTS

We randomized 586 subjects, 293 to each arm. The crude PEP rates were 5.5% (allopurinol) and 4.1% (placebo), (P = .44; difference = 1.4%; 95% confidence interval, -2.1% to 4.8%). The Mantel-Haenszel combined risk ratio for PEP with allopurinol, considering stratification, was 1.37 (95% confidence interval, 0.65-2.86). Subgroup analyses suggested nonsignificant trends toward possible benefit in the high-risk group, and possible harm for the remaining subjects. Logistic regression found pancreatic therapy, pancreatic injection, and prior PEP to be the only independent predictors of PEP.

CONCLUSIONS

Allopurinol does not appear to reduce the overall risk of PEP; however, its potential benefit in the high-risk group (but potential harm for non-high-risk patients) means further study is required.

New advances in acute pancreatitis

PURPOSE OF REVIEW

We endeavor to review important new advances in acute pancreatitis made in the past year. We focused on clinical aspects of acute pancreatitis, which contained new observations or insights into new or old concepts. For experimental acute pancreatitis we refer readers to a recent comprehensive review.

RECENT FINDINGS

Recently, case fatality rates of acute pancreatitis have stabilized; carbohydrate-deficient transferrin was shown to predict alcoholic acute pancreatitis; idiopathic chronic pancreatitis or occult cholelithiasis have been associated with 'recurrent acute pancreatitis' in most patients; and cystic fibrosis transmembrane conductance regulator genetic mutations were frequently found (10-50%) in patients with recurrent acute pancreatitis. In addition, alcohol was shown to increase the risk of pancreatic necrosis regardless of the cause of acute pancreatitis. Persistent organ failure and multiple organ dysfunction syndrome but not necessarily extent of necrosis were demonstrated to predict increased mortality in acute pancreatitis. Chemoprevention of post-endoscopic retrograde cholangiopancreatography acute pancreatitis remains unproven. Enteral feeding has been strongly recommended in severe acute pancreatitis. Finally, data are lacking for routine, prophylactic antibiotic administration to all patients with pancreatic necrosis.

SUMMARY

We reviewed studies this past year that further characterize the epidemiology, etiology and risk stratification of acute pancreatitis. Evolving areas include chemoprevention of post-endoscopic retrograde cholangiopancreatography acute pancreatitis and enteral feeding and antibiotics in severe acute pancreatitis. We await translation of novel therapies from the bench to bedside.

Pancreatits after endoscopic retrograde cholangio-pancreatography

Pancreatitis is the most common complication after endoscopic retrograde cholangio-pancreatography (ERCP); the reported incidence of this complication varies from less than 1% to 40%, but a rate of 4%-8% is reported in most prospective studies involving non-selected patients. Differences in criteria for defining pancreatitis, methods of data collection, and patient populations (i.e. number of high-risk patients included in the published series) are factors that are likely to affect the varying rates of post-ERCP pancreatitis. The severity of post-ERCP pancreatitis (PEP) can range from a minor inconvenience with one or two days of added hospitalization with full recovery to a devastating illness with pancreatic necrosis, multiorgan failure, permanent disability, and even death. Although, most episodes of PEP are mild (about 90%), a small percentage of patients (about 10%) develop moderate or severe pancreatitis. In the past, PEP was often viewed as an unpredictable and unavoidable complication, with no realistic strategy for its avoidance. New data have aided in stratification of patients into PEP risk categories and new measures have been introduced to decrease the risk of PEP. As most ERCPs are performed on an outpatient basis, the majority of patients will not develop PEP and can be discharged. Alternatively, early detection of those patients who will go on to develop PEP can guide decisions regarding hospital admission and aggressive management. In the last decade, great efforts have been addressed toward prevention of this complication. Points of emphasis have included technical measures, pharmacological prophylaxis, and patient selection. This review provides a comprehensive, evidence-based assessment of published data on PEP and current suggestions for its avoidance.

Updates in biliary endoscopy 2006

PURPOSE OF REVIEW

Endoscopic retrograde cholangiopancreatography is reserved primarily for therapeutic reasons. Recent literature continues to support therapeutic uses of the technique. This review addresses the literature in the field of biliary endoscopy for the year 2006 and is intended to assist gastroenterologists and gastrointestinal surgeons in everyday practice.

RECENT FINDINGS

Endoscopic management of choledocholithiasis in gallstone pancreatitis, a newer approach in the endoscopic management of malignant biliary strictures, the broadening therapeutic indications including the use of gallbladder stenting and the performance of endoscopic retrograde cholangiopancreatography in patients with Roux-en-Y gastric bypass are discussed. Safety of the technique continues to be addressed. The risks of pancreatitis after endoscopic retrograde cholangiopancreatography as well as morbidity in the elderly are addressed.

SUMMARY

Major updates in the management of biliary tract disease using biliary endoscopy are discussed over a broad range of biliary tract diseases. The literature emphasizes the broadening therapeutic role of endoscopic retrograde cholangiopancreatography as well as improvements in our understanding of risk factors for complications and the potential for their prevention.