Unraveling the mystery of pain in chronic pancreatitis

Pain in chronic pancreatitis: What can we do today?

The aim of this study is to illustrate the complexity of pain management in chronic pancreatitis (CP). In this context, pain represents the most common and debilitating symptom, and it deeply affects patient's quality of life. Multiple rating scales (unidimensional, bidimensional and multidimensional) have been proposed to quantify CP pain. However, it represents the result of complex mechanisms, involving genetic, neuropathic and neurogenic factors. Considering all these aspects, the treatment should be discussed in a multidisciplinary setting and it should be approached in a stepwise manner. First, a lifestyle change is recommended and nonsteroidal anti-inflammatory drugs represent the gold standard among medical treatments for CP patients. The second step, after medical approach, is endoscopic therapy, especially for complicated CP. In case of failure, tailored surgery represents the third step and decompressive or resection procedures can be chosen. In conclusion, CP pain's management is challenging considering all these complex aspects and the lack of international protocols.

Predictors of persistent pain after extracorporeal shockwave lithotripsy for painful chronic calcific pancreatitis

BACKGROUND

Extracorporeal shockwave lithotripsy (ESWL) and/or endoscopic retrograde cholangiopancreatography (ERCP) are recommended as first-line therapy for painful uncomplicated chronic pancreatitis with obstructed main pancreatic duct (MPD) in the pancreas head/body. However, predictors of pain relief after ESWL are unknown. We evaluated independent predictors of persistent pain in patients who underwent ESWL for chronic pancreatitis.

METHODS

640 consecutive adult patients with chronic pancreatitis, who underwent successful ESWL with ERCP and pancreatic duct (PD) stent placement, were followed for 12 months. The pain was assessed at baseline and at 12 months using the Izbicki Pain Score, with a score decrease of >50% considered pain relief. Independent predictors of pain relief were derived from logistic regression analysis.

RESULTS

Of 640 patients (mean age 36.71 [SD 12.19] years; 60.5% men), 436 (68.1%) had pain relief and 204 (31.9%) had persistent pain. On univariate analysis, older age, male sex, alcohol and tobacco intake, longer duration of symptoms, dilated MPD and MPD stricture were associated with persistent pain at 12 months (P<0.05). Consumption of alcohol (odds ratio [OR] 1.93, 95%CI 1.26-2.97), tobacco (OR 4.09, 95%CI 2.43-6.90), duration of symptoms (OR 1.02, 95%CI 1.01-1.04), MPD size (OR 1.22, 95%CI 1.11-1.33), and MPD stricture (OR 8.50, 95%CI 5.01-14.42) were independent predictors of persistent pain.

CONCLUSIONS

Alcohol, tobacco, duration of symptoms, MPD size and stricture were independent predictors of persistent pain after successful ESWL. A multidisciplinary team approach that includes behavioral therapy and surgical options should be considered for such patients.

Diffuse calcification of pancreas impairs endocrine function and predicts poor outcome in total pancreatectomy with islet autotransplantation

In patients with chronic pancreatitis, pancreatic calcification is a risk factor for diabetes development, poor islet yield, and metabolic outcomes after total pancreatectomy with islet autotransplantation (TPIAT). We investigated whether calcification pattern based on computed tomography is associated with outcomes using our database of 200 consecutive TPIAT procedures. Three groups were compared: noncalcification (NC); focal calcification, limited to the pancreas head, body, or tail; and diffuse calcification (DC), with calcification in >2 sections. Maximum changes in outcomes were seen in the DC vs focal calcification group. In the DC group, preoperative hemoglobin A1c levels were higher (P < .01), and stimulated C-peptide levels were lower (P < .01) than in the NC group. Islet isolation from the DC pancreas resulted in the lowest islet equivalent (IEQ) yield and IEQ/kg among the 3 groups (P < .0001), with no insulin independence 12 months posttransplant (P < .05 vs NC group). Notably, at 12 months, the DC group was 91.7% narcotic-free, significantly higher than the NC group (P < .05). Although DC is a sign of diabetes risk after TPIAT, the DC group showed exceptional pain relief. These findings suggest that TPIAT can be beneficial for patients with chronic pancreatitis with severe calcification.

I Feel! Therefore, I Am from Pain to Consciousness in DOC Patients

Pain assessment and management in patients with disorders of consciousness (DOC) is a challenging and important aspect of care, with implications for detecting consciousness and promoting recovery. This narrative review explores the role of pain in consciousness, the challenges of pain assessment, pharmacological treatment in DOC, and the implications of pain assessment when detecting changes in consciousness. The review discusses the Nociception Coma Scale and its revised version, which are behavioral scales used to assess pain in DOC patients, and the challenges and controversies surrounding the appropriate pharmacological treatment of pain in these patients. Moreover, we highlight recent evidence suggesting that an accurate pain assessment may predict changes in the level of consciousness in unresponsive wakefulness syndrome/vegetative state patients, underscoring the importance of ongoing pain management in these patients.

Efficacy and Predictors of Pain Response to Combined Antioxidants in Children with Chronic Pancreatitis

BACKGROUND

Pain is a major problem in 90% of patients with chronic pancreatitis (CP). Studies evaluating response to antioxidants (AO) are conflicting and no pediatric studies are available.

AIMS

To evaluate markers of oxidative stress (OS), and efficacy and predictors of response to AO in improving pain in children with CP.

METHODS

Antioxidants were given to CP children for 6 months. Subjects were assessed at baseline and post-therapy for pain and markers of OS [serum thiobarbituric acid reactive substances (TBARS), superoxide dismutase (S-SOD)] and antioxidant levels [vitamin C, selenium, total antioxidant capacity-ferric reducing ability of plasma (FRAP)]. Matched healthy controls were assessed for OS and antioxidant levels. Good response was defined as ≥ 50% reduction in number of painful days/month.

RESULTS

48 CP children (25 boys, age 13 years) and 14 controls were enrolled. 38/48 cases completed 6 months of therapy. CP cases had higher OS [TBARS (7.8 vs 5.2 nmol/mL; p < 0.001)] and lower antioxidant levels [FRAP (231 vs. 381.3 µmol/L; p = 0.003), vitamin C (0.646 vs. 0.780 mg/dL; p < 0.001)] than controls. Significant reduction in TBARS and S-SOD and increase in FRAP, vitamin C, and selenium occurred after 6 months. 10.5% cases had minor side effects. 26(68%) cases had a good response, with 9(24%) becoming pain-free. Subjects with severe ductal changes had lower median BMI (- 0.73 vs 0.10; p = 0.04) and responded less often than those with mild changes (17/29 vs 9/9; p = 0.036).

CONCLUSION

CP children have higher OS than healthy controls. Antioxidant therapy is safe. Pain response is seen in 68% cases, less often in patients with severe ductal changes.

Endoscopic Management of Complications in Chronic Pancreatitis

PURPOSE OF REVIEW

Management of complications in patients with chronic pancreatitis is often suboptimal. This review discusses detailed endoscopic approaches for managing complications in CP.

LITERATURE FINDINGS

CP is characterized by progressive and irreversible destruction of pancreatic parenchyma and ductal system resulting in fibrosis, scarring, and loss of glandular function. Abdominal pain remains is the most common symptom of the disease and the main aim of medical, endoscopic, and surgical therapy is to help relieve symptoms, prevent disease progression, and manage complications related to CP. In fact, advances in our understanding of CP have improved medical care and quality of life in these patients. With significant sequela, morbidity and a progressive nature, a thorough understanding of the pathophysiology, natural course, diagnostic approaches, and optimal management strategies for this disease is warranted. The existing modalities and new innovations in this field are safe, effective, and likely to have a positive impact on management of complication in CP whenever used in the right context.

Intra-sphincteric botulinum toxin in the management of functional biliary pain

Background and study aims  The management of functional biliary-type pain remains a clinical challenge. Intra sphincteric botulinum toxin putatively exerts an anti-spasmodic and anti-nociceptive effect. The objective of this study was to examine the clinical response to intra sphincteric botulinum toxin in patients with functional biliary-type pain. Patients and methods  This was a cross-sectional (hypothesis-generating) study of prospectively collected data from patients referred to a tertiary center from 2014 to 2019. The efficacy of ampullary botulinum toxin injection for relief of pain was recorded at post-procedure outpatient review. Opioid analgesia, neuromodulatory medication, and frequency of hospital admissions were recorded. Results  A total of 119 consecutive patients (109 women, 10 men, mean age 45 years; range 17-77) underwent 411 intra-sphincteric botulinum toxin injection procedures (mean 2 procedures; range 1-15). A total of 103 patients (87 %) had a significant improvement in pain on post-procedure review and 77 % and 76 % of patients were opioid and admission free, respectively. Of the patients, 59 % were prescribed tricyclic antidepressants (amitriptyline), 18 % duloxetine, 13 % pregabalin, and 3 % mirtazapine. Loss of response with the initial dose of botulinum toxin occurred in 56 % of patients. Pain control was reestablished in 80 % of patients in this cohort following botulinum toxin injection at a higher dose. Conclusions  These data suggest that botulinum toxin may improve outcomes in patients with functional biliary pain. Further controlled studies are needed to clarify the role of Botox and neuromodulatory agents.

Anterior Cingulate Cortex Mediates Hyperalgesia and Anxiety Induced by Chronic Pancreatitis in Rats

Central sensitization is essential in maintaining chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. Here, we examined the role of the anterior cingulate cortex (ACC) in the pathogenesis of abdominal hyperalgesia in a rat model of CP induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). TNBS treatment resulted in long-term abdominal hyperalgesia and anxiety in rats. Morphological data indicated that painful CP induced a significant increase in FOS-expressing neurons in the nucleus tractus solitarii (NTS) and ACC, and some FOS-expressing neurons in the NTS projected to the ACC. In addition, a larger portion of ascending fibers from the NTS innervated pyramidal neurons, the neural subpopulation primarily expressing FOS under the condition of painful CP, rather than GABAergic neurons within the ACC. CP rats showed increased expression of vesicular glutamate transporter 1, and increased membrane trafficking and phosphorylation of the N-methyl-D-aspartate receptor (NMDAR) subunit NR2B and the α-amino-3-hydroxy-5-methyl-4-isoxazole propionic acid receptor (AMPAR) subunit GluR1 within the ACC. Microinjection of NMDAR and AMPAR antagonists into the ACC to block excitatory synaptic transmission significantly attenuated abdominal hyperalgesia in CP rats, which was similar to the analgesic effect of endomorphins injected into the ACC. Specifically inhibiting the excitability of ACC pyramidal cells via chemogenetics reduced both hyperalgesia and comorbid anxiety, whereas activating these neurons via optogenetics failed to aggravate hyperalgesia and anxiety in CP rats. Taken together, these findings provide neurocircuit, biochemical, and behavioral evidence for involvement of the ACC in hyperalgesia and anxiety in CP rats, as well as novel insights into the cortical modulation of painful CP, and highlights the ACC as a potential target for neuromodulatory interventions in the treatment of painful CP.

Effect of pancreatic endotherapy on quality of life in chronic pancreatitis patients: A systematic review

BACKGROUND

Pancreatic endotherapy provides treatment options for the management of chronic pancreatitis-related structural complications such as pancreatic duct stones, strictures, and pancreatic fluid collections. Most studies detailing endotherapy, however, have focused on technical success outcomes such as stone clearance or stricture resolution.

AIM

To review the effect of pancreatic endotherapy on patient-centered outcomes.

METHODS

Systematic review of studies examining pancreatic endotherapy.

RESULTS

A total of 13 studies including 3 randomized clinical trials were included. The majority of studies found an improvement in quality of life with pancreatic endotherapy.

CONCLUSION

While pancreatic endotherapy does appear to improve quality of life, there are clear gaps in knowledge regarding many pancreatic endotherapy modalities. Furthermore, qualitative analysis is lacking in these studies and further work is needed to elucidate the patient experience with pancreatic endotherapy.

Pancreatic Pain-Knowledge Gaps and Research Opportunities in Children and Adults: Summary of a National Institute of Diabetes and Digestive and Kidney Diseases Workshop

ABSTRACT

A workshop was sponsored by the National Institute of Diabetes and Digestive and Kidney Diseases to focus on research gaps and opportunities in pancreatic pain. The event was held on July 21, 2021, and structured into 4 sessions: (1) pathophysiology; (2) biomarkers, mediators, and pharmacology of pain; (3) pain assessment; and (4) pain treatment challenges and opportunities. The current state of knowledge was reviewed; many knowledge gaps and research needs were identified that require further investigation. Common themes included the need to better understand the underlying mechanisms of pain in pancreatic diseases, the relationship of visceral neural pathways and central pain centers, the role of behavioral factors and disorders on the perception of pain, and differences in pain perception and processes in children when compared with adults. In addition, the role of genetic risk factors for pain and the mechanisms and role of placebos in pain treatment were discussed. Methods of pain assessment including quantitative sensory testing were examined, as well as the process of central sensitization of pain. Finally, newer approaches to pain management including cognitive behavioral therapy, nerve stimulation, experimental (nonopioid) drugs, and cannabinoid compounds were covered.

Mesenchymal stromal cell therapy for pancreatitis: Progress and challenges

Pancreatitis is a common gastrointestinal disease with no effective therapeutic options, particularly for cases of severe acute and chronic pancreatitis (CP). Mesenchymal stromal cells (MSCs) are multipotent cells with diverse biological properties, including directional migration, paracrine, immunosuppressive, and antiinflammatory effects, which are considered an ideal candidate cell type for repairing tissue damage caused by various pathogenies. Several researchers have reported significant therapeutic efficacy of MSCs in animal models of acute and CP. However, the specific underlying mechanisms are yet to be clarified and clinical application of MSCs as pancreatitis therapy has rarely been reported. This review mainly focuses on the potential and challenges in clinical application of MSCs for treatment of acute and CP, along with discussion of the underlying molecular mechanisms.

Severe Pain in Chronic Pancreatitis Patients: Considering Mental Health and Associated Genetic Factors

Pain is the most distressing and disruptive feature of recurrent acute pancreatitis (RAP) and chronic pancreatitis (CP) resulting in low quality of life (QOL) and disabilities. There is no single, characteristic pain pattern in patients with RAP and CP. Abdominal imaging features of CP accurately reflect morphologic features but they do not correlate with pain. Pain is the major driver of poor quality of life (QOL) and it is the constant pain, rather than intermittent pain that drives poor QOL. Furthermore, the most severe constant pain experience in CP is also a complex condition. The ability to target the etiopathogenesis of severe pain requires new methods to detect the exact pain mechanisms in an individual at cellular, tissue, system and psychiatric levels. In patients with complex and severe disease, it is likely that multiple overlapping mechanisms are simultaneously driving pain, anxiety and depression. Quantitative sensory testing (QST) shows promise in detecting alterations in central processing of pain signals and to classify patients for mechanistic and therapeutic studies. New genetic research suggests that genetic loci for severe pain in CP overlap with genetic loci for depression and other psychiatric disorders, providing additional insights and therapeutic targets for individual patients with severe CP pain. Well-designed clinical trials that integrate clinical features, QST, genetics and psychological assessments with targeted treatment and assessment of responses are required for a quantum leap forward. A better understanding of the context and mechanisms contributing to severe pain experiences in individual patients is predicted to lead to better therapies and quality of life.

Adverse Events Associated With Therapeutic Endoscopic Retrograde Pancreatography

OBJECTIVES

Data regarding the safety of endoscopic retrograde pancreatography (ERP) are limited compared with biliary endoscopic retrograde cholangiopancreatography. The aim of this study was to determine adverse events (AEs) associated with therapeutic ERP.

METHODS

This single-center retrospective study examined consecutive therapeutic ERPs with the primary intention of cannulating the pancreatic duct. Multivariate logistic regression was performed to identify risk factors for AEs.

RESULTS

A total of 3023 ERPs were performed in 1288 patients (mean age, 50.3 years; 57.8% female) from January 2000 to January 2017. Overall AE rate was 18.9% with abdominal pain requiring admission (9.8%) and post-ERP pancreatitis (5.7%) being most common. On multivariate analysis, female sex (adjusted odds ratio [aOR], 2.3; 95% confidence interval [CI], 1.9-2.9), acute recurrent pancreatitis (aOR, 5.0; 95% CI, 1.7-15.3), chronic pancreatitis (aOR, 1.8; 95% CI, 1.3-2.6), and pancreatic sphincter of Oddi dysfunction (aOR, 2.1; 95% CI, 1.4-3.3) were associated with an increased risk of overall AEs. Pancreatic sphincterotomy (aOR, 1.9; 95% CI, 1.5-2.4) and therapeutic stenting (aOR, 1.6; 95% CI, 1.2-2.2) also increased the risk of AEs.

CONCLUSIONS

Nearly 1 in 5 patients who undergo therapeutic ERP will experience an AE; however, the rates of major AEs, including post-ERP pancreatitis, bleeding, and perforation, are low.

Optical Imaging of Pancreatic Innervation

At the time of Ivan Pavlov, pancreatic innervation was studied by looking at pancreas secretions in response to electrical stimulation of nerves. Nowadays we have ways to visualize neuronal activity in real time thanks to advances in fluorescent reporters and imaging techniques. We also have very precise optogenetic and pharmacogenetic approaches that allow neuronal manipulations in a very specific manner. These technological advances have been extensively employed for studying the central nervous system and are just beginning to be incorporated for studying visceral innervation. Pancreatic innervation is complex, and the role it plays in physiology and pathophysiology of the organ is still not fully understood. In this review we highlight anatomical aspects of pancreatic innervation, techniques for pancreatic neuronal labeling, and approaches for imaging pancreatic innervation in vitro and in vivo.

Endoscopic intervention in pancreatitis: perspectives from a gastroenterologist

The last decade has seen a dramatic paradigm shift for the treatment of pancreatitis and its related complications away from surgery to minimally invasive endoscopic approaches. In this review, we provide an overview of the indications, techniques and outcomes of endoscopic interventions in the management of acute and chronic pancreatitis. Emphasis is placed on drainage of pancreatic pseudocysts and treatment of pain in chronic pancreatitis.

Combined extracorporeal shock wave lithotripsy and endoscopic treatment for pain in chronic pancreatitis (SCHOKE trial): study protocol for a randomized, sham-controlled trial

Background

Pain is the primary symptom of chronic pancreatitis (CP) and remains a considerable therapeutic challenge. In patients with obstruction of the pancreatic duct, including stones and strictures, endoscopic treatment with or without preceding extracorporeal shock wave lithotripsy (ESWL) has been used for pancreatic duct decompression. The rationale for these procedures is based on the assumption that obstruction of the pancreatic duct leads to ductal hypertension and pain. However, clinical pain symptoms correlate poorly with pancreatic duct morphology, and the evidence for pancreatic duct decompression as an effective treatment for pain is based on case series and comparison between different procedures. No randomized, prospective, sham-controlled trials are currently available. The SCHOKE (Extracorporeal Shock Wave Lithotripsy and Endotherapy for Pain in Chronic Pancreatitis) trial is a randomized, sham-controlled trial designed to determine if pancreatic duct decompression is an effective treatment for pain in patients with CP.

Methods

The SCHOKE trial is a randomized, single-blind, parallel-group, sham-controlled trial designed to evaluate the effect of combined ESWL and endoscopic treatment for pain in patients with CP. In total, 106 adult patients with painful CP and pancreatic duct obstruction will be randomized to combined ESWL and subsequent endoscopic treatment or corresponding sham procedures. The primary outcome is pain relief during the 3-month postrandomization period as documented in a pain diary. Secondary outcomes include quality of life and functional scores, patient global impression of change, change in use of analgesics, frequency of hospitalization, and complications. Standard follow-up is at 3 and 6 months after randomization. In an experimental substudy, quantitative sensory testing obtained before and after intervention will be used to obtain information on central pain processing and to develop models for prediction of treatment outcome.

Discussion

The SCHOKE trial investigates if pancreatic duct decompression, obtained by combined ESWL and endoscopic treatment, is effective for pain treatment in patients with CP.

Trial registration

ClinicalTrials.gov, NCT03966781. Registered on May 25, 2019.

Protocol date and version identifier: March 1, 2020; version 3.0.

Sponsor: Rupjyoti Talukdar, Department of Medical Gastroenterology, Asian Institute of Gastroenterology, Hyderabad, Telangana, India.

30-Day outcomes and predictors of complications after Puestow procedure

BACKGROUND

A lateral pancreaticojejunostomy, or a Puestow procedure, is used in chronic pancreatitis with ductal dilation and pain. The current literature on the Puestow is sparse. This study examines outcomes of Puestow procedures nationwide.

METHODS

Using ACS-NSQIP database, patients who underwent a Puestow procedure from 2010 to 2016 were identified. Univariate analysis and multivariable regression models were used to identify predictors of mortality and morbidities. Covariates included in the regression models were chosen based on clinical significance.

RESULTS

The cohort included 524 patients. The 30-day mortality rate was 1.2%(n = 6). At least one major complication occurred in 19.1% of patients including death (1.2%), major organ dysfunction (8.2%), pulmonary embolism (1.3%), and surgical site infections (13.0%). Diabetes, COPD, and transfusions were the strongest predictors of complications.

CONCLUSIONS

The Puestow procedure is an acceptable treatment modality with low rates of morbidity and mortality. Minimizing transfusions and optimizing pulmonary status may improve 30-day outcomes.

Evolution of nociception and pain: evidence from fish models

In order to survive, animals must avoid injury and be able to detect potentially damaging stimuli via nociceptive mechanisms. If the injury is accompanied by a negative affective component, future behaviour should be altered and one can conclude the animal experienced the discomfort associated with pain. Fishes are the most successful vertebrate group when considering the number of species that have filled a variety of aquatic niches. The empirical evidence for nociception in fishes from the underlying molecular biology, neurobiology and anatomy of nociceptors through to whole animal behavioural responses is reviewed to demonstrate the evolutionary conservation of nociception and pain from invertebrates to vertebrates. Studies in fish have shown that the biology of the nociceptive system is strikingly similar to that found in mammals. Further, potentially painful events result in behavioural and physiological changes such as reduced activity, guarding behaviour, suspension of normal behaviour, increased ventilation rate and abnormal behaviours which are all prevented by the use of pain-relieving drugs. Fish also perform competing tasks less well when treated with a putative painful stimulus. Therefore, there is ample evidence to demonstrate that it is highly likely that fish experience pain and that pain-related behavioural changes are conserved across vertebrates. This article is part of the Theo Murphy meeting issue 'Evolution of mechanisms and behaviour important for pain'.

Nucleus tractus solitarius mediates hyperalgesia induced by chronic pancreatitis in rats

BACKGROUND

Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP). We hypothesized that the nucleus tractus solitarius (NTS), a primary central site that integrates pancreatic afferents apart from the thoracic spinal dorsal horn, plays a key role in the pathogenesis of visceral hypersensitivity in a rat model of CP.

AIM

To investigate the role of the NTS in the visceral hypersensitivity induced by chronic pancreatitis.

METHODS

CP was induced by the intraductal injection of trinitrobenzene sulfonic acid (TNBS) in rats. Pancreatic hyperalgesia was assessed by referred somatic pain via von Frey filament assay. Neural activation of the NTS was indicated by immunohistochemical staining for Fos. Basic synaptic transmission within the NTS was assessed by electrophysiological recordings. Expression of vesicular glutamate transporters (VGluTs), N-methyl-D-aspartate receptor subtype 2B (NR2B), and α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid receptor subtype 1 (GluR1) was analyzed by immunoblotting. Membrane insertion of NR2B and GluR1 was evaluated by electron microscopy. The regulatory role of the NTS in visceral hypersensitivity was detected via pharmacological approach and chemogenetics in CP rats.

RESULTS

TNBS treatment significantly increased the number of Fos-expressing neurons within the caudal NTS. The excitatory synaptic transmission was substantially potentiated within the caudal NTS in CP rats (frequency: 5.87 ± 1.12 Hz in CP rats vs 2.55 ± 0.44 Hz in sham rats, P < 0.01; amplitude: 19.60 ± 1.39 pA in CP rats vs 14.71 ± 1.07 pA in sham rats; P < 0.01). CP rats showed upregulated expression of VGluT2, and increased phosphorylation and postsynaptic trafficking of NR2B and GluR1 within the caudal NTS. Blocking excitatory synaptic transmission via the AMPAR antagonist CNQX and the NMDAR antagonist AP-5 microinjection reversed visceral hypersensitivity in CP rats (abdominal withdraw threshold: 7.00 ± 1.02 g in CNQX group, 8.00 ± 0.81 g in AP-5 group and 1.10 ± 0.27 g in saline group, P < 0.001). Inhibiting the excitability of NTS neurons via chemogenetics also significantly attenuated pancreatic hyperalgesia (abdominal withdraw threshold: 13.67 ± 2.55 g in Gi group, 2.00 ± 1.37 g in Gq group, and 2.36 ± 0.67 g in mCherry group, P < 0.01).

CONCLUSION

Our findings suggest that enhanced excitatory transmission within the caudal NTS contributes to pancreatic pain and emphasize the NTS as a pivotal hub for the processing of pancreatic afferents, which provide novel insights into the central sensitization of painful CP.

Anterior insular cortex mediates hyperalgesia induced by chronic pancreatitis in rats

Central sensitization plays a pivotal role in the maintenance of chronic pain induced by chronic pancreatitis (CP), but cortical modulation of painful CP remains elusive. This study was designed to examine the role of anterior insular cortex (aIC) in the pathogenesis of hyperalgesia in a rat model of CP. CP was induced by intraductal administration of trinitrobenzene sulfonic acid (TNBS). Abdomen hyperalgesia and anxiety were assessed by von Frey filament and open field tests, respectively. Two weeks after surgery, the activation of aIC was indicated by FOS immunohistochemical staining and electrophysiological recordings. Expressions of VGluT1, NMDAR subunit NR2B and AMPAR subunit GluR1 were analyzed by immunoblottings. The regulatory roles of aIC in hyperalgesia and pain-related anxiety were detected via pharmacological approach and chemogenetics in CP rats. Our results showed that TNBS treatment resulted in long-term hyperalgesia and anxiety-like behavior in rats. CP rats exhibited increased FOS expression and potentiated excitatory synaptic transmission within aIC. CP rats also showed up-regulated expression of VGluT1, and increased membrane trafficking and phosphorylation of NR2B and GluR1 within aIC. Blocking excitatory synaptic transmission significantly attenuated abdomen mechanical hyperalgesia. Specifically inhibiting the excitability of insular pyramidal cells reduced both abdomen hyperalgesia and pain-related anxiety. In conclusion, our findings emphasize a key role for aIC in hyperalgesia and anxiety of painful CP, providing a novel insight into cortical modulation of painful CP and shedding light on aIC as a potential target for neuromodulation interventions in the treatment of CP.

The Management of Chronic Pancreatitis

Chronic pancreatitis (CP) may remain undiagnosed for years until patients exhibit manifestations, such as pain and exocrine or endocrine insufficiency. Some patients with CP develop serious complications, such as malignancy or peripancreatic fluid collections. Considering CP in at-risk patients such as those with a long-standing history of alcohol or tobacco use is key to establishing the diagnosis. Management involves reducing and eliminating exposures, dietary modification, treatment of pancreatic insufficiency, assessing for complications, and surveillance for neoplasia. The management of CP is often multidisciplinary involving medical, endoscopic, and surgical options for therapy.

Neuronal Transforming Growth Factor beta Signaling via SMAD3 Contributes to Pain in Animal Models of Chronic Pancreatitis

BACKGROUND & AIMS

Chronic pancreatitis (CP) is characterized by pancreatic inflammation and fibrosis, associated with increased pancreatic expression of transforming growth factor beta (TGFB). It is not clear how these might contribute to pain. We investigated whether TGFB signaling via SMAD induces sensitization of pancreatic sensory neurons to increase nociception.

METHODS

CP was induced in Sprague-Dawley rats by infusion of trinitrobenzene sulfonic acid; some rats were given intrathecal infusions of TGFB1. CP was induced in control mice by administration of cerulein; we also studied β1glo/Ptf1acre-ER mice, which on induction overexpress TGFB1 in pancreatic acinar cells, and TGFBr1^{f/f-CGRPcreER} mice, which have inducible disruption of TGFBr1 in calcitonin gene-related peptide-positive neurons. Dominant negative forms of human TGFBR2 and SMAD3 were overexpressed from viral vectors in rat pancreas. Some rats were given the SMAD3 inhibitors SIS3 or halofuginone. After induction of CP, mice were analyzed for pain in behavior tests or electrophysiologic studies of sensory neurons. Pancreatic nociceptor excitability was examined by patch-clamp techniques and nociception was measured by Von Frey Filament tests for referred somatic hyperalgesia and behavioral responses to pancreatic electrical stimulation. Pancreata were collected from mice and rats and analyzed histologically and by enzyme-linked immunosorbent assay and immunohistochemistry.

RESULTS

Overexpression of TGFB in pancreatic acinar cells of mice and infusion of TGFB1 into rats resulted in sensory neuron hyperexcitability, SMAD3 activation, and increased nociception. This was accompanied by a reduction in the transient A-type current in pancreas-specific sensory neurons in rats, a characteristic of nociceptive sensitization in animal models of CP. Conversely, pancreata from TGFBr1^{f/f-CGRPcreER} mice, rats with pancreatic expression of dominant negative forms of human TGFBR2 or SMAD3, and rats given small molecule inhibitors of SMAD3 had attenuated neuronal sensitization and pain behavior following induction of CP. In contrast to findings from peripheral administration of TGFB1, intrathecal infusion of TGFB1 reduced hyperalgesia in rats with CP.

CONCLUSIONS

In pancreata of mice and rats, TGFB promotes peripheral nociceptive sensitization via a direct effect on primary sensory neurons mediated by intra-neuronal SMAD3. This is distinct from the central nervous system, where TGFB reduces nociception. These results provide an explanation for the link between fibrosis and pain in patients with CP. This signaling pathway might be targeted therapeutically to reduce pain in patients with CP.

A pilot-study of hypnotherapy as complementary treatment for pain in chronic pancreatitis

Background

Chronic pain is the hallmark symptom of chronic pancreatitis (CP). Its treatment is complicated, and often the patients have side-effects notwithstanding that pain is not ameliorated in many cases. Hypnotherapy has been shown to improve symptoms of irritable bowel syndrome including abdominal pain and, as such, may serve as a remedy to relive pain. The aim of this open-label pilot-study was to test the effect of hypnotherapy for pain in patients with CP.

Methods

Four patients with CP and chronic abdominal pain were included and followed for four consecutive weeks. The primary efficacy parameter was pain relief. After 1 week of baseline patients received a 1-h session of hypnotherapy. This was repeated at day 15 and day 23 and supplemented by self-administered hypnotherapy.

Results

Three of four participants completed the trial and experienced short lasting pain reduction during the trial. The reported pain relief was in the range of 20%–39% compared to baseline. Hypnotherapy improved self-reported sleep, vitality, and social life.

Conclusions

The results suggest that hypnotherapy may reduce pain related to CP. Furthermore, no adverse effects were reported and the majority of participants completed the trial. Further prospective controlled trials are warranted to examine the potential of hypnotherapy.

Age and Disease Duration Impact Outcomes of Total Pancreatectomy and Islet Autotransplant for PRSS1 Hereditary Pancreatitis

OBJECTIVES

We investigated the impact of patient age and disease duration on islet isolation results, diabetes outcomes, and pain outcomes after total pancreatectomy with islet autotransplant (TPIAT) performed in 64 patients with hereditary pancreatitis due to PRSS1 gene mutation.

METHODS

We evaluated the association of patient age and disease duration on islet isolation results and opioid use at 1 year using logistic regression and on graft function using 1-way analysis of variance.

RESULTS

Islet mass was negatively associated with increasing age and longer disease duration, with a 13% reduction (95% confidence interval [CI], 3%-22%) and 22% (95% CI, 14%-29%) reduction in islet equivalents per kilogram body weight (IEQ/kg) for each 5 years of age and disease duration, respectively. Full graft function was associated with younger age and shorter duration of disease (P < 0.01). Persistent opioid use (15% of patients at 1 year) increased with age (P = 0.05) and disease duration (P = 0.04).

CONCLUSIONS

The TPIAT outcomes were adversely impacted by older age and prolonged disease. In particular, islet mass is lower and risk of diabetes high in older patients with prolonged disease. This should be considered when counseling this subgroup of TPIAT recipients on expected outcomes.

A multicenter study of total pancreatectomy with islet autotransplantation (TPIAT): POST (Prospective Observational Study of TPIAT)

BACKGROUND/OBJECTIVES

Total pancreatectomy with islet autotransplantation (TPIAT) is considered for managing chronic pancreatitis in selected patients when medical and endoscopic interventions have not provided adequate relief from debilitating pain. Although more centers are performing TPIAT, we lack large, multi-center studies to guide decisions about selecting candidates for and timing of TPIAT.

METHODS

Multiple centers across the United States (9 to date) performing TPIAT are prospectively enrolling patients undergoing TPIAT for chronic pancreatitis into the Prospective Observational Study of TPIAT (POST), a NIDDK funded study with a goal of accruing 450 TPIAT recipients. Baseline data include participant phenotype, pancreatitis history, and medical/psychological comorbidities from medical records, participant interview, and participant self-report (Medical Outcomes Survey Short Form-12, EQ-5D, andPROMIS inventories for pain interference, depression, and anxiety). Outcome measures are collected to at least 1 year after TPIAT, including the same participant questionnaires, visual analog pain scale, pain interference scores, opioid requirements, insulin requirements, islet graft function, and hemoglobin A1c. Health resource utilization data are collected for a cost-effectiveness analysis. Biorepository specimens including urine, serum/plasma, genetic material (saliva and blood), and pancreas tissue are collected for future study.

CONCLUSIONS

This ongoing multicenter research study will enroll and follow TPIAT recipients, aiming to evaluate patient selection and timing for TPIAT to optimize pain relief, quality of life, and diabetes outcomes, and to measure the procedure's cost-effectiveness. A biorepository is also established for future ancillary studies.

Comparative Physiology of Nociception and Pain

The study of diverse animal groups allows us to discern the evolution of the neurobiology of nociception. Nociception functions as an important alarm system alerting the individual to potential and actual tissue damage. All animals possess nociceptors, and, in some animal groups, it has been demonstrated that there are consistent physiological mechanisms underpinning the nociceptive system. This review considers the comparative biology of nociception and pain from an evolutionary perspective.

Towards a neurobiological understanding of pain in chronic pancreatitis: mechanisms and implications for treatment

We summarize the evidence for a neurobiological understanding of pain in patients with chronic pancreatitis and discuss its potential impact on prevention and treatment.

Introduction:

Chronic pancreatitis (CP) is a disease characterized by inflammation of the pancreas resulting in replacement of the normal functioning parenchyma by fibrotic connective tissue. This process leads to progressively impairment of exocrine and endocrine function and many patients develop a chronic pain syndrome.

Objectives:

We aimed to characterize the neurobiological signature of pain associated with CP and to discuss its implications for treatment strategies.

Methods:

Relevant basic and clinical articles were selected for review following an extensive search of the literature.

Results:

Pathophysiological changes in the peripheral (pancreatic gland) and central nervous system characterize the pain syndrome associated with CP; involved mechanisms can be broken down to 3 main branches: (1) peripheral sensitization, (2) pancreatic neuropathy, and (3) neuroplastic changes in the central pain pathways. Disease flares (recurrent pancreatitis) may accelerate the pathophysiological process and further sensitize the pain system, which ultimately results in an autonomous and self-perpetuating pain state that may become independent of the peripheral nociceptive drive. These findings share many similarities with those observed in neuropathic pain disorders and have important implications for treatment; adjuvant analgesics are effective in a subset of patients, and neuromodulation and neuropsychological interventions may prove useful in the future.

Conclusion:

Chronic pancreatitis is associated with abnormal processing of pain at the peripheral and central level of the pain system. This neurobiological understanding of pain has important clinical implications for treatment and prevention of pain chronification.

Serum endocannabinoids in assessing pain in patients with chronic pancreatitis and in those with pancreatic ductal adenocarcinoma

BACKGROUND

The endocannabinoid system plays a substantial role in analgesia.

AIM

To analyze N-arachidonoylethanolamine (AEA), N-oleoylethanolamine (OEA), linoleoyl ethanolamide (LEA), α-linoleoyl ethanolamine (α-LNEA), N-palmitoylethanolamine (PEA) and N-stearoyl ethanolamine (SEA) in two groups of patients having chronic pancreatic diseases.

PATIENTS AND METHODS

Twenty-six patients with chronic pancreatitis, 26 patients with pancreatic ductal adenocarcinoma and 36 healthy subjects were studied. The visual analogic scale (VAS) was used for assessing pain immediately before the venipuncture to obtain blood in all subjects. Six endocannabinoids were measured in serum of the patients enrolled.

RESULTS

Only OEA, LEA and PEA serum levels were significantly higher in patients with pain as compared to those without. Using the cutoff values, the sensitivity and specificity of the various endocannabinoids in evaluating pain in patients with chronic pancreatitis and in those with pancreatic ductal adenocarcinoma were: 44.2% and 95.6% for AEA, 83.7% and 73.3% for LEA, 88.4% and 91.1% for LNEA, 81.4% and 82.2% for OEA, 81.4% and 88.9% for PEA, 86.0% and 88.9% for SEA, respectively.

CONCLUSION

Endocannabinoids are not useful in assessing pain in patients with chronic pancreatic diseases and they cannot replace a simple method such as VAS for assessing the pain and its intensity.

Total Pancreatectomy With Islet Autotransplantation for Acute Recurrent and Chronic Pancreatitis

PURPOSE OF REVIEW

The first total pancreatectomy and islet autotransplantation (TP-IAT) was performed for chronic pancreatitis in 1977 with the goal to ameliorate the pain and simultaneously preserve islet function. We reviewed the recent medical literature regarding indications, patient suitability, current outcomes, and challenges in TP-IAT.

RECENT FINDINGS

Current indications for TP-IAT include intractable pain secondary to chronic pancreatitis (CP) or acute recurrent pancreatitis (ARP) with failed medical and endoscopic/surgical management. Independent studies have shown that TP-IAT is associated with elimination or significant improvement in pain control and partial or full islet graft function in the majority of patients. In single-center cost analyses, TP-IAT has been suggested to be more cost-effective than medical management of chronic pancreatitis. While initially introduced as a surgical option for adults with long-standing chronic pancreatitis, TP-IAT is now often utilized in children with chronic pancreatitis and in children and adults with intractable acute recurrent pancreatitis. The surgical procedure has evolved over time with some centers offering minimally invasive operative options, although the open approach remains the standard. Despite many advances in TP-IAT, there is a need for further research and development in disease diagnosis, patient selection, optimization of surgical technique, islet isolation and quality assessment, postoperative patient management, and establishment of uniform metrics for data collection and multicenter studies. TP-IAT is an option for patients with otherwise intractable acute recurrent or chronic pancreatitis which presents potential for pain relief and improved quality of life, often with partial or complete diabetes remission.

Total pancreatectomy for recurrent acute and chronic pancreatitis: a critical review of patient selection criteria

PURPOSE OF REVIEW

Critical review of the indications for total pancreatectomy and highlight limitations in current diagnostic criteria for chronic pancreatitis.

RECENT FINDINGS

The diagnosis of noncalcific chronic pancreatitis remains controversial because of an overreliance on nonspecific imaging and laboratories findings. Endoscopic ultrasound, s-magnetic resonance cholangiopancreatography, and/or endoscopic pancreatic function testing are often used to diagnose noncalcific chronic pancreatitis despite the fact that there is no gold standard for this condition. Abdominal pain is not specific for chronic pancreatitis and is more likely to be encountered in patients with functional gastrointestinal disorders based on the high incidence of these conditions. The duration of pain and opioid analgesic use results in central sensitization that adversely affects pain outcomes after total pancreatectomy. An alcoholic cause is associated with poorer pain outcomes after total pancreatectomy.

SUMMARY

The lack of a gold standard for noncalcific chronic pancreatitis limits the diagnostic accuracy of imaging and laboratory tests. The pain of chronic pancreatitis is nonspecific and is affected by duration, preoperative opioid use, and cause. These factors will need to be considered in the development of future selection criteria for this morbid surgery.

Chronic pancreatitis

PURPOSE OF REVIEW

Summarize key clinical advances in chronic pancreatitis reported in 2016.

RECENT FINDINGS

Early diagnosis of chronic pancreatitis remains elusive. Recent studies suggest that endoscopic ultrasound may be less accurate than previously thought and new MRI techniques may be helpful. Genetic predisposition may independently affect the clinical course of chronic pancreatitis and the risk for pancreatic cancer. Cigarette smoking may have a greater negative impact on chronic pancreatitis than previously thought and moderate alcohol consumption may be protective. A multidisciplinary approach is necessary for the treatment of type 3 diabetes and nutritional deficiencies in chronic pancreatitis. Although endoscopic therapy remains a reasonable first-line option in treating chronic pancreatitis and its complications, early surgical intervention may be indicated for pain in select patients.

SUMMARY

Newer endoscopic ultrasound and MRI techniques are being evaluated to help with the early diagnosis of chronic pancreatitis. Both genetic predisposition and cigarette smoking are increasingly recognized as having a major impact in the course of the disease and the risk for pancreatic cancer. Endoscopic therapy is well tolerated and effective for the treatment of chronic pancreatitis and its complications although an early surgical approach for pain may be associated with improved clinical outcomes.

Guidelines for the understanding and management of pain in chronic pancreatitis

Abdominal pain is the foremost complication of chronic pancreatitis (CP). Pain can be related to recurrent or chronic inflammation, local complications or neurogenic mechanisms with corresponding changes in the nervous systems. Both pain intensity and the frequency of pain attacks have been shown to reduce quality of life in patients with CP. Assessment of pain follows the guidelines for other types of chronic pain, where the multidimensional nature of symptom presentation is taken into consideration. Quantitative sensory testing may be used to characterize pain, but is currently used in a research setting in advanced laboratories. For pain relief, current guidelines recommend a simple stepwise escalation of analgesic drugs with increasing potency until pain relief is obtained. Abstinence from alcohol and smoking should be strongly advised. Pancreatic enzyme therapy and antioxidants may be helpful as initial treatment. Endoscopic treatment can be used in patients with evidence of ductal obstruction and may be combined with extracorporeal shock wave lithothripsy. The best candidates are those with distal obstruction of the main pancreatic duct and in early stage of disease. Behavioral interventions should be part of the multidisciplinary approach to chronic pain management particularly when psychological impact is experienced. Surgery should be considered early and after a maximum of five endoscopic interventions. The type of surgery depends on morphological changes of the pancreas. Long-term effects are variable, but high success rates have been reported in open studies and when compared with endoscopic treatment. Finally, neurolytical interventions and neuromodulation can be considered in difficult patients.

Medical Management of Pain in Chronic Pancreatitis

The medical management of pain in chronic pancreatitis continues to pose significant challenges for clinicians caring for these patients. There are increasing data, suggesting that pain in chronic pancreatitis is largely due to peripheral and central sensitization that evolves, over time, as a result of nociceptive afferent associated with chronic inflammation and fibrosis of the pancreas. In many instances, patients rapidly progress to requiring opioid analgesics for the adequate treatment of pain despite the unequivocal risks associated with the long-term use of these drugs. Centrally acting drugs, such as gabapentinoids, appear to be effective means of treating pain due to their inhibition of neurotransmitters involved in central sensitization, but side effects limit their use. The present review explores the evidence for various non-pharmacologic and pharmacologic treatments for pain in chronic pancreatitis.

Acute physiological and electrical accentuation of vagal tone has no effect on pain or gastrointestinal motility in chronic pancreatitis

Background

The effective management of pain in chronic pancreatitis (CP) remains a therapeutic challenge. Analgesic drugs, such as opioids, and the underlying pathology can impair gut function. The autonomic nervous system influences hormone secretion and gut motility. In healthy volunteers, electrical (using noninvasive transcutaneous vagal nerve stimulation [t-VNS]) and physiological (using deep slow breathing [DSB]) modulation of parasympathetic tone results in pain attenuation and enhanced gut motility. Thus, the aims were to investigate whether t-VNS and DSB could enhance the parasympathetic tone, decrease pain sensitivity and improve gut motility in CP.

Patients and methods

A total of 20 patients (12 males, mean age=61 years, range: 50–78 years) with CP were randomized to short-term (60 minutes) t-VNS and DSB, or their placebo equivalent, in a crossover design. Cardiometrically derived parameters of autonomic tone, quantitative sensory testing of bone and muscle pain pressure, conditioned pain modulation (CPM) and assessments of gastroduodenal motility with ultrasound were performed.

Results

In comparison to sham, t-VNS and DSB increased cardiac vagal tone (CVT) (P<0.001). However, no changes in pain pressure thresholds for bone (P=0.95) or muscle (P=0.45) were seen. There was diminished CPM (P=0.04), and no changes in gastroduodenal motility were observed (P=0.3).

Conclusion

This explorative study demonstrated that t-VNS and DSB increased CVT in patients with CP. However, this short-lasting increase did not affect pain sensitivity to musculoskeletal pain or gastroduodenal motility. The chronic pain in CP patients is complex, and future trials optimizing neuromodulation for pain relief and improved motility are needed.

Post-cholecystectomy syndrome and sphincter of Oddi dysfunction: past, present and future

Post-cholecystectomy syndrome and the concept of a causal relationship to sphincter of Oddi dysfunction, despite the controversy, has presented a clinically relevant conflict for decades. Historically surgeons, and now gastroenterologists have expended tremendous efforts towards trying to better understand the dilemma that is confounded by unique patient phenotypes. Areas covered: This review encompasses the literature from a century of experience on the topic of post-cholecystectomy syndrome. Relevant historical and anecdotal experiences are examined in the setting of insights from evaluation of recently available controlled data. Expert commentary: Historical observations and recent data suggest that patients with post-cholecystectomy syndrome can be categorized as follows. Patients with sphincter of Oddi stenosis will most often benefit from treatment with sphincterotomy. Patients with classic biliary pain and some objective evidence of biliary obstruction may have a sphincter of Oddi disorder and should be considered for endoscopic evaluation and therapy. Patients with atypical post-cholecystectomy pain, without any evidence consistent with biliary obstruction, and/or with evidence for another diagnosis or dysfunction should not undergo ERCP.

Total Pancreatectomy With Islet Autotransplantation Improves Quality of Life in Patients With Refractory Recurrent Acute Pancreatitis

BACKGROUND & AIMS

Therapeutic options are limited for patients with recurrent acute pancreatitis who have intractable symptoms despite maximal endoscopic and medical treatment, but equivocal or no morphologic or functional evidence of chronic pancreatitis. We performed a prospective observational cohort study to determine the efficacy of total pancreatectomy with islet autotransplantation (TPIAT) for these patients.

METHODS

We collected data from all patients undergoing TPIAT at the University of Minnesota from 2007 through 2013; 49 patients (42 female; mean age, 32.8 ± 7.8 years) had a diagnosis of recurrent acute pancreatitis not provoked by intervention, with negative or equivocal findings from nondiagnostic imaging or pancreatic function tests for chronic pancreatitis, and intractable pain between episodes. Data on insulin use, narcotic requirements, pain scores, and health-related quality of life were collected before TPIAT; 3 months, 6 months, and 1 year afterward; and then yearly.

RESULTS

All 49 patients studied required narcotics before TPIAT (45 daily users and 4 intermittent users); 2 had insulin-treated diabetes. At 1 year after TPIAT, 22 out of 48 patients (46%) reported no use of narcotic pain medications (P < .001 vs baseline). Health-related quality of life score, measured by the physical and mental component summary score, increased by approximately 1 standard deviation from the population mean (P < .001 for the physical component summary; P = .019 for the mental component summary). At 1 year after TPIAT, 21 out of 48 patients (45%) were insulin independent; their mean percent glycosylated hemoglobin A1c at 1 year after TPIAT was 6.0% ± 0.9% (5.2% ± 0.6% pre-TPIAT).

CONCLUSIONS

Patients with recurrent acute pancreatitis but lacking clear chronic pancreatitis benefit from TPIAT, with outcomes similar to those previously described for patients with chronic pancreatitis (improved quality of life and reduced narcotic use). For these patients who have otherwise limited surgical treatment options, TPIAT can be considered when medical and endoscopic therapies have failed.

Interventional Pain Management Approaches for Control of Chronic Pancreatic Pain

OPINION STATEMENT

Treatment of persistent pain from chronic pancreatitis historically was difficult to treat. For years, focus was on opioid and other analgesics and psychological treatments. Recent studies provided evidence for decrease in analgesic intake and pain scores after properly conducted sympathetic blocks (celiac, splanchnic nerve blocks). These therapies should be considered as parts of a multimodal analgesic strategy. Animal studies suggest that spinal cord stimulation suppresses visceral hyperalgesia. Large case series of spinal cord stimulation demonstrated a significant pain relief in patients with chronic pancreatitis. Given the limitations of conservative and surgical treatments for chronic visceral pain, spinal cord stimulation may be a very useful therapeutic option.

Chronic pancreatitis

Chronic pancreatitis describes a wide spectrum of fibro-inflammatory disorders of the exocrine pancreas that includes calcifying, obstructive, and steroid-responsive forms. Use of the term chronic pancreatitis without qualification generally refers to calcifying chronic pancreatitis. Epidemiology is poorly defined, but incidence worldwide seems to be on the rise. Smoking, drinking alcohol, and genetic predisposition are the major risk factors for chronic calcifying pancreatitis. In this Seminar, we discuss the clinical features, diagnosis, and management of chronic calcifying pancreatitis, focusing on pain management, the role of endoscopic and surgical intervention, and the use of pancreatic enzyme-replacement therapy. Management of patients is often challenging and necessitates a multidisciplinary approach.

Rome IV. Gallbladder and Sphincter of Oddi Disorders

The concept that motor disorders of the gallbladder, cystic duct and sphincter of Oddi can cause painful syndromes is attractive and popular, at least in the USA. However, the results of commonly performed ablative treatments (cholecystectomy and sphincterotomy) are not uniformly good. The predictive value of tests that are often used to diagnose dysfunction (dynamic gallbladder scintigraphy and sphincter manometry) is controversial. Evaluation and management of these patients is made difficult by the fluctuating symptoms and the placebo effect of invasive interventions. A recent stringent study has shown that sphincterotomy is no better than sham treatment in patients with post-cholecystectomy pain and little or no objective abnormalities on investigation, so that the old concept of sphincter of Oddi dysfunction (SOD) type III is discarded. ERCP approaches are no longer appropriate in that context. There is a pressing need for similar prospective studies to provide better guidance for clinicians dealing with these patients. We need to clarify the indications for cholecystectomy in patients with Functional Gallbladder Disorder (FGBD) and the relevance of sphincter dysfunction in patients with some evidence for biliary obstruction (previously SOD type II, now called "Functional Biliary Sphincter Disorder - FBSD") and with idiopathic acute recurrent pancreatitis.

Mechanism, assessment and management of pain in chronic pancreatitis: Recommendations of a multidisciplinary study group

DESCRIPTION

Pain in patients with chronic pancreatitis (CP) remains the primary clinical complaint and source of poor quality of life. However, clear guidance on evaluation and treatment is lacking.

METHODS

Pancreatic Pain working groups reviewed information on pain mechanisms, clinical pain assessment and pain treatment in CP. Levels of evidence were assigned using the Oxford system, and consensus was based on GRADE. A consensus meeting was held during PancreasFest 2012 with substantial post-meeting discussion, debate, and manuscript refinement.

RESULTS

Twelve discussion questions and proposed guidance statements were presented. Conference participates concluded: Disease Mechanism: Pain etiology is multifactorial, but data are lacking to effectively link symptoms with pathologic feature and molecular subtypes. Assessment of Pain: Pain should be assessed at each clinical visit, but evidence to support an optimal approach to assessing pain character, frequency and severity is lacking.

MANAGEMENT

There was general agreement on the roles for endoscopic and surgical therapies, but less agreement on optimal patient selection for medical, psychological, endoscopic, surgical and other therapies.

CONCLUSIONS

Progress is occurring in pain biology and treatment options, but pain in patients with CP remains a major problem that is inadequately understood, measured and managed. The growing body of information needs to be translated into more effective clinical care.

Alcohol and high fat induced chronic pancreatitis: TRPV4 antagonist reduces hypersensitivity

The pathogenesis of pain in chronic pancreatitis is poorly understood, and its treatment can be a major clinical challenge. Surgical and other invasive methods have variable outcomes that can be unsatisfactory. Therefore, there is a great need for further discovery of the pathogenesis of pancreatitis pain and new therapeutic targets. Human and animal studies indicate a critical role for oxidative stress and activation of transient receptor potential (TRP) cation channel subfamily members TRPV1 and TRPA1 on pancreatic nociceptors in sensitization mechanisms that result in pain. However, the in vivo role of transient receptor potential cation channel subfamily V member 4 (TRPV4) in chronic pancreatitis needs further evaluation. The present study characterized a rat alcohol/high fat diet (AHF)-induced chronic pancreatitis model with hypersensitivity, fibrotic pathology, and fat vacuolization consistent with the clinical syndrome. The rats with AHF-induced pancreatitis develop referred visceral pain-like behaviors, i.e. decreased hindpaw mechanical thresholds and shortened abdominal and hindpaw withdrawal latency to heat. In this study, oxidative stress was characterized as well as the role of TRPV4 in chronic visceral hypersensitivity. Lipid peroxidase and oxidative stress were indicated by increased plasma thiobarbituric acid reactive substances (TBARS) and diminished pancreatic manganese superoxide dismutase (MnSOD). The secondary sensitization associated with AHF-induced pancreatitis was effectively alleviated by the TRPV4 antagonist, HC 067047. Similarity of the results to those with the peripherally restricted μ-opiate receptor agonist, loperamide, suggested TRPV4 channel activated peripheral sensitization. This study using a reliable model that provides pre-clinical correlates of human chronic pancreatitis provides further evidence that TRPV4 channel is a potential therapeutic target for treatment of pancreatitis pain.

Current understanding of the neuropathophysiology of pain in chronic pancreatitis

Chronic pancreatitis (CP) is a chronic inflammatory disease of the pancreas. The main symptom of patients with CP is chronic and severe abdominal pain. However, the pathophysiology of pain in CP remains obscure. Traditionally, researchers believed that the pain was caused by anatomical changes in pancreatic structure. However, treatment outcomes based on such beliefs are considered unsatisfactory. The emerging explanations of pain in CP are trending toward neurobiological theories. This article aims to review current evidence regarding the neuropathophysiology of pain in CP and its potential implications for the development of new treatments for pain in CP.