Morphologic abnormalities are poorly predictive of visceral pain in chronic pancreatitis

Chronic pancreatitis: Pain and computed tomography/magnetic resonance imaging findings

Chronic pancreatitis (CP) is a fibroinflammatory disease characterized by irreversible destruction of pancreatic tissue. With the development of the disease, it may lead to exocrine and/or endocrine insufficiency. CP is one of the common diseases that cause abdominal pain, which will not get permanent spontaneous relief as the disease evolves. The American College of Gastroenterology clinical guidelines recommend computed tomography or magnetic resonance imaging as the first-line examination for the diagnosis of CP. CP common imaging findings include pancreatic atrophy, irregular dilatation of the pancreatic duct, calcification of pancreatic parenchyma, pancreatic duct stones, etc. In clinical practice, whether any correlations between CP-induced abdominal pain patterns (no pain/constant/intermittent pain) and corresponding imaging findings present are not well known. Therefore, this review aims to comprehensively sort out and analyze the relevant information by collecting lots of literature on this field, so as to construct a cross-bridge between the clinical manifestations and imaging manifestations of CP patients. Also, it provides an imaging basis and foundation for the classification and diagnosis of abdominal pain types in clinical CP patients.

Structural imaging findings are related to clinical complications in chronic pancreatitis

BACKGROUND/OBJECTIVES

Structural pancreatic changes and complications related to chronic pancreatitis are well described, but little is known about their relationship. We aimed to explore the associations between pancreatic morphology and clinical complications in a large chronic pancreatitis cohort.

METHODS

The Scandinavian Baltic Pancreatic Club database collects registrations on patients with definite or probable chronic pancreatitis according to the M-ANNHEIM diagnostic criteria. In this cross-sectional study, we used multivariate logistic regression analyses to evaluate whether imaging-based structural pancreatic changes were associated with common clinical complications. We adjusted for sex, age, disease duration, current alcohol abuse and current smoking.

RESULTS

We included 742 patients with a mean age of 55 years. Among these, 68% were males, 69% had pancreatic exocrine insufficiency, 35% had diabetes, 12% were underweighted and 68% reported abdominal pain. Main pancreatic duct obstruction, severe (i.e. more than 14) calcifications, pancreatic atrophy and parenchymal changes throughout the entire pancreas (continuous organ involvement) were positively associated with pancreatic exocrine insufficiency. Continuous organ involvement and pseudocysts were positively and negatively associated with diabetes, respectively. Pancreatic atrophy and severe calcifications were positively associated with underweight, and severe calcifications were negatively associated with pain.

CONCLUSIONS

This study shows independent associations between distinct structural changes on pancreatic imaging and clinical complications in chronic pancreatitis. Pancreatic atrophy, severe calcifications and continuous organ involvement may be of particular clinical relevance, and these findings should motivate monitoring of pancreatic function and nutritional status.

Secretin-Enhanced MRCP: How and Why-AJR Expert Panel Narrative Review

Secretin-enhanced MRCP (S-MRCP) has advantages over standard MRCP for imaging of the pancreaticobiliary tree. Through the use of secretin to induce fluid production from the pancreas and leveraging of fluid-sensitive MRCP sequences, S-MRCP facilitates visualization of ductal anatomy, and the findings provide insight into pancreatic function, allowing radiologists to provide additional insight into a range of pancreatic conditions. This narrative review provides detailed information on the practical implementation of S-MRCP, including patient preparation, logistics of secretin administration, and dynamic secretin-enhanced MRCP acquisition. Also discussed are radiologists' interpretation and reporting of S-MRCP examinations, including assessments of dynamic compliance of the main pancreatic duct and of duodenal fluid volume. Established indications for S-MRCP include pancreas divisum, anomalous pancreaticobiliary junction, Santorinicele, Wirsungocele, chronic pancreatitis, main pancreatic duct stenosis, and assessment of complex postoperative anatomy. Equivocal or controversial indications are also described along with an approach to such indications. These indications include acute and recurrent acute pancreatitis, pancreatic exocrine function, sphincter of Oddi dysfunction, and pancreatic neoplasms.

Progression of pancreatic morphology in chronic pancreatitis is not associated with changes in quality of life and pain

OBJECTIVES

In patients with chronic pancreatitis (CP), the aim was to explore the association between pancreatic morphological progression over four years and corresponding changes in disease characteristics, including quality of life (QOL), pain, and exocrine pancreatic function.

METHODS

Twenty-five patients with CP were followed by magnetic resonance imaging (MRI). Data were obtained at baseline and after 4-year follow-up, including clinical information, QOL, and pain as assessed by validated questionnaires. Morphological assessments were derived from the same MRI scanner and included pancreatic gland volume, apparent diffusion coefficient values, fat signal fraction, and main pancreatic duct diameter.

RESULTS

After four years, CP patients showed significant progression in morphological parameters of the pancreas, except for the ductal-related changes (p < .13). Hence, patients developed reduced pancreatic volume by 13.5% (p < .001), an increase of fibrosis by 10.8% (p < .001), and an increase of fat infiltration by 7.6% (p < .001). In contrast, the patient-reported outcomes of QOL and pain did not change significantly over four years (all p > .05). Moreover, the progression of morphological imaging findings was not related to changes in QOL, pain severity, and pain interference (all p > .05). There was, however, an association between the 4-year progression of pancreatic atrophy and the decrease in fecal elastase concentration (r = 0.61; p < .001).

CONCLUSIONS

Progression of gland morphology in CP did not correlate with changes in the quality of life or pain symptoms. Advanced pancreatic imaging techniques may be a highly sensitive tool for monitoring morphological disease progression, but do not directly reflect patients' disease burden.

Idiopathic recurrent acute pancreatitis

Idiopathic recurrent acute pancreatitis is clinically challenging and has substantial socioeconomic consequences. Investigations are expensive and often reveal little about the cause of the disease. Little is known about the interaction between genetic, environmental, anatomical, and other factors that contribute to the disease. Data on the efficacy, safety, and long-term outcomes of endoscopic therapies are scarce. The effect of idiopathic recurrent pancreatitis on quality of life is often underestimated. A more thorough examination of the causes of the disease and the roles of other associated risk factors is needed, as are well designed clinical studies with robust and objectively measurable outcomes. Ideally, evaluation of the causes of disease and therapy should be done only in specialised centres, should follow a protocol, and all outcomes should be formally assessed.

Quantification of parenchymal calcifications in chronic pancreatitis: relation to atrophy, ductal changes, fibrosis and clinical parameters

OBJECTIVES

Parenchymal calcifications are considered a hallmark finding of chronic pancreatitis (CP), but little is known about its relation to the clinical presentation and other morphological features such as atrophy, fibrosis and ductal changes. The aim was to quantify the number and maximal size of parenchymal calcifications assessed on computed tomography (CT) and to explore the association with other CT and magnetic resonance imaging (MRI)-based pancreatic features and clinical parameters.

METHODS

A well-characterised cohort of 54 CP patients was included. CT measurements included number and size of parenchymal calcifications, gland diameter and ductal diameter. MRI measurements included gland volume, ductal diameter, fibrosis (diffusion) and fatty infiltration (Dixon). Clinical parameters included body mass index (BMI), CP duration and aetiology, M-ANNHEIM clinical stage, tobacco use, alcohol consumption, the presence of diabetes, faecal elastase, clinical pain score and quality of life.

RESULTS

There were no correlations between the number and size of parenchymal calcifications and any of the other morphological CT and MRI parameters (all p > .05), except for larger size of calcifications in patients with high number of calcifications (p < .001). The number of parenchymal calcifications was negatively correlated with BMI (r = -0.35, p = .0088). The number and size of parenchymal calcifications did not correlate with any of the other clinical parameters (all p > .2).

CONCLUSION

Our findings could indicate the existence of parenchymal calcifications as an independent pathophysiological process involved in the development of CP. Translational impact: Quantifications of calcifications could, in combination with other imaging biomarkers, be a useful imaging marker relevant for characterising CP.

Diagnosis and treatment in chronic pancreatitis: an international survey and case vignette study

BACKGROUND

The aim of the study was to evaluate the current opinion and clinical decision-making process of international pancreatologists, and to systematically identify key study questions regarding the diagnosis and treatment of chronic pancreatitis (CP) for future research.

METHODS

An online survey, including questions regarding the diagnosis and treatment of CP and several controversial clinical case vignettes, was send by e-mail to members of various international pancreatic associations: IHPBA, APA, EPC, ESGE and DPSG.

RESULTS

A total of 288 pancreatologists, 56% surgeons and 44% gastroenterologists, from at least 47 countries, participated in the survey. About half (48%) of the specialists used a classification tool for the diagnosis of CP, including the Mayo Clinic (28%), Mannheim (25%), or Büchler (25%) tools. Overall, CT was the preferred imaging modality for evaluation of an enlarged pancreatic head (59%), pseudocyst (55%), calcifications (75%), and peripancreatic fat infiltration (68%). MRI was preferred for assessment of main pancreatic duct (MPD) abnormalities (60%). Total pancreatectomy with auto-islet transplantation was the preferred treatment in patients with parenchymal calcifications without MPD abnormalities and in patients with refractory pain despite maximal medical, endoscopic, and surgical treatment. In patients with an enlarged pancreatic head, 58% preferred initial surgery (PPPD) versus 42% initial endoscopy. In patients with a dilated MPD and intraductal stones 56% preferred initial endoscopic ± ESWL treatment and 29% preferred initial surgical treatment.

CONCLUSION

Worldwide, clinical decision-making in CP is largely based on local expertise, beliefs and disbeliefs. Further development of evidence-based guidelines based on well designed (randomized) studies is strongly encouraged.

MRI assessed pancreatic morphology and exocrine function are associated with disease burden in chronic pancreatitis

BACKGROUND AND AIM

The aim of this study was to explore the association between morphological and functional secretin-stimulated MRI parameters with hospitalization, quality of life (QOL), and pain in patients with chronic pancreatitis (CP).

PATIENTS AND METHODS

This prospective cohort study included 82 patients with CP. Data were obtained from clinical information, QOL, and pain as assessed by questionnaires (The European Organization for Research and Treatment of Cancer Quality of Life Questionnaire and modified Brief Pain Inventory short form). Secretin-stimulated MRI morphological parameters included pancreatic gland volume, main pancreatic duct diameter, the modified Cambridge Classification of Duct Abnormality, apparent diffusion coefficient, fat signal fraction, and the pancreatic secretion volume as a functional parameter. The primary outcomes were time to first hospitalization related to the CP, as well as annual hospitalization frequency and duration. The secondary outcomes were pain severity, QOL, and pain interference scores.

RESULTS

A main pancreatic duct diameter below 5 mm was associated with reduced time to first hospitalization (hazard ratio=2.06; 95% confidence interval: 1.02-4.17; P=0.043). Pancreatic secretion volume was correlated with QOL (r=0.31; P=0.0072) and pain interference score (r=-0.27; P=0.032), and fecal elastase was also correlated with QOL (r=0.28; P=0.017). However, functional and morphological findings were not related to pain intensity.

CONCLUSION

Advanced pancreatic imaging techniques may be a highly sensitive tool for prognostication and monitoring of disease activity and its consequences.

Combined circulating tumor DNA and protein biomarker-based liquid biopsy for the earlier detection of pancreatic cancers

The earlier diagnosis of cancer is one of the keys to reducing cancer deaths in the future. Here we describe our efforts to develop a noninvasive blood test for the detection of pancreatic ductal adenocarcinoma. We combined blood tests for KRAS gene mutations with carefully thresholded protein biomarkers to determine whether the combination of these markers was superior to any single marker. The cohort tested included 221 patients with resectable pancreatic ductal adenocarcinomas and 182 control patients without known cancer. KRAS mutations were detected in the plasma of 66 patients (30%), and every mutation found in the plasma was identical to that subsequently found in the patient's primary tumor (100% concordance). The use of KRAS in conjunction with four thresholded protein biomarkers increased the sensitivity to 64%. Only one of the 182 plasma samples from the control cohort was positive for any of the DNA or protein biomarkers (99.5% specificity). This combinatorial approach may prove useful for the earlier detection of many cancer types.

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.

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.

Diagnostic Performance of Contrast-Enhanced MRI With Secretin-Stimulated MRCP for Non-Calcific Chronic Pancreatitis: A Comparison With Histopathology

OBJECTIVES

Diagnosis of non-calcific chronic pancreatitis (NCCP) in patients presenting with chronic abdominal pain is challenging and controversial. Contrast-enhanced magnetic resonance imaging (MRI) with secretin-stimulated MRCP (sMRCP) offers a safe and noninvasive modality to diagnose mild CP, but its findings have not been correlated with histopathology. We aimed to assess the correlation of a spectrum of MRI/sMRCP findings with surgical histopathology in a cohort of NCCP patients undergoing total pancreatectomy with islet autotransplantation (TPIAT).

METHODS

Adult patients undergoing TPIAT for NCCP between 2008 and 2013 were identified from our institution's surgery database and were included if they had MRI/sMRCP within a year before surgery. Histology was obtained from resected pancreas at the time of TPIAT by wedge biopsy of head, body, and tail, and was graded by a gastrointestinal pathologist who was blinded to the imaging features. A fibrosis score (FS) of 2 or more was considered as abnormal, with FS ≥6 as severe fibrosis. A multivariate regression analysis was performed for MRI features predicting fibrosis, after taking age, sex, smoking, alcohol, and body mass index (BMI) into consideration. A quantitative receiver operating characteristic (ROC) curve analysis was performed and Spearman rank correlation coefficient (r) was calculated.

RESULTS

Fifty-seven patients (females=49, males=8) with NCCP and MRI/sMRCP were identified. ROC curve analysis showed that two or more MRI/sMRCP features provided the best balance of sensitivity (65%), specificity (89%), and accuracy (68%) to differentiate abnormal (FS≥2) from normal pancreatic tissue. Two or more features provided the best cutoff (sensitivity 88%, specificity 78%) for predicting severe fibrosis (FS≥6). There was a significant correlation between the number of features and severity of fibrosis (r=0.6, P<0.0001). A linear regression after taking age, smoking, and BMI into consideration showed that main pancreatic duct irregularity, T1-weighted signal intensity ratio between pancreas and paraspinal muscle, and duodenal filling after secretin injection to be significant independent predictors of fibrosis.

CONCLUSIONS

A strong correlation exists between MRI/sMRCP findings and histopathology of NCCP.

Chronic pancreatitis pain pattern and severity are independent of abdominal imaging findings

BACKGROUND & AIMS

Chronic pancreatitis is characterized by inflammation, atrophy, fibrosis with progressive ductal changes, and functional changes that include variable exocrine and endocrine insufficiency and multiple patterns of pain. We investigated whether abdominal imaging features accurately predict patterns of pain.

METHODS

We collected data from participants in the North American Pancreatitis Study 2 Continuation and Validation, a prospective multicenter study of patients with chronic pancreatitis performed at 13 expert centers in the United States from July 2008 through March 2012. Chronic pancreatitis was defined based on the detection of characteristic changes by cross-sectional abdominal imaging, endoscopic retrograde cholangiopancreatography, endoscopic ultrasonography, or histology analyses. Patients were asked by a physician or trained clinical research coordinator if they had any abdominal pain during the year before enrollment, those who responded "yes" were asked to select from a list of 5 pain patterns. By using these patterns, we classified patients' pain based on timing and severity. Abnormal pancreatitis-associated features on abdominal imaging were recorded using standardized case report forms.

RESULTS

Data were collected from 518 patients (mean age, 52 ± 14.6 y; 55% male; and 87.6% white). The most common physician-identified etiologies were alcohol (45.8%) and idiopathic (24.3%); 15.6% of patients reported no abdominal pain in the year before enrollment. The most common individual pain pattern was described as constant mild pain with episodes of severe pain and was reported in 45% of patients. The most common imaging findings included pancreatic ductal dilatation (68%), atrophy (57%), and calcifications (55%). Imaging findings were categorized as obstructive for 20% and as inflammatory for 25% of cases. The distribution of individual imaging findings was similar among patients with different patterns of pain. The distribution of pain patterns did not differ among clinically relevant groups of imaging findings.

CONCLUSIONS

Mechanisms that determine patterns and severity of pain in patients with chronic pancreatitis are largely independent of structural variants observed by abdominal imaging techniques. Pancreas-relevant quantitative and qualitative pain measures should be included in the evaluation of patients with chronic pancreatitis to assess pain severity independently of imaging findings.

Chronic pancreatitis

PURPOSE OF REVIEW

We review selected important clinical observations in chronic pancreatitis reported in 2013.

RECENT FINDINGS

Early diagnosis of chronic pancreatitis remains difficult, although newer techniques utilizing endoscopic ultrasonography-elastography and MRI hold promise. Patients with chronic pancreatitis are at risk of nutritional deficiencies. Osteoporosis, osteopenia, and bone fracture are particularly common in these patients, and require active intervention and treatment. Diabetes caused by chronic pancreatitis, type 3c diabetes, has specific characteristics and requires careful management. Antioxidants and neuromodulators may decrease pain in some patients with chronic pancreatitis. Endoscopic treatment is effective and can be utilized in patients with painful chronic pancreatitis, although randomized trials demonstrate that surgical therapy is somewhat more durable and effective. Although surgery has typically been a last resort, some advocate early surgical intervention but the optimal time remains unknown.

SUMMARY

Early diagnosis of pancreatitis may be improved by newer techniques associated with endoscopic ultrasonography imaging. Treatment of nutritional deficiencies and diabetes is an important aspect of treating chronic pancreatitis. Pain relief with adjunct means of pain modulation should be tried before starting narcotics for pain control. Endoscopic therapy is appropriate for treating chronic pancreatitis and its local complications and surgical intervention can be considered early in carefully selected individuals.

Total pancreatectomy with islet cell auto-transplantation: update and outcomes from major centers

OPINION STATEMENT

Chronic pancreatitis is the result of irreversible damage to pancreatic acinar cells, and can result in debilitating chronic pain for patients. Treatment centers on pain relief, often with chronic narcotic use. Surgical therapy consists of both resection procedures to remove affected pancreatic parenchyma and drainage procedures to facilitate drainage of the main pancreatic duct. Total pancreatectomy historically was utilized in extreme cases due to the brittle glucose control that followed from the total loss of islet cells. Total pancreatectomy with islet cell auto-transplantation (TP-AIT) is gaining in popularity due to the maintenance of beta cell mass and the ability of patients to potentially be insulin independent post-operatively. TP-AIT is very helpful in the treatment of pain for patients with chronic pancreatitis. The overall majority of patients have an improvement in pain and quality-of-life scores. AIT also allows the majority of patients to have minimal insulin requirements post-operatively. With proper patient selection, these outcomes can be achieved.

Fibrosis, atrophy, and ductal pathology in chronic pancreatitis are associated with pancreatic function but independent of symptoms

OBJECTIVES

More knowledge into the pathophysiology underlying pain and other complications in chronic pancreatitis (CP) is needed. The aim was to associate advanced imaging information of the pancreas with etiology and clinical and laboratory parameters of CP.

METHODS

Magnetic resonance cholangiopancreatography including diffusion-weighted imaging was obtained in 23 patients with painful CP and 17 controls. Apparent diffusion coefficients, ductal pathology, and pancreas atrophy were assessed. Etiology of CP and clinical and laboratory parameters including pain scores were correlated with the imaging findings.

RESULTS

The patients had restricted apparent diffusion coefficients, that is, fibrotic changes, compared with the controls (P = 0.0003). The diffusion coefficients were not associated with atrophy- or ductal-related parameters (all P > 0.7). The fibrotic changes as well as atrophy- and ductal-related parameters were not associated with pain or any other symptom parameters (all P > 0.05). Alcoholic etiology was associated with ductal pathology (both P = 0.02). Furthermore, atrophy- and ductal-related parameters were associated with vitamin D, phosphate, hemoglobin, and glycated hemoglobin levels (all P < 0.03).

CONCLUSIONS

Patients with CP have fibrosis, atrophy, and ductal pathology. Although changes in atrophy- and ductal-related parameters were, to some degree, associated with exocrine and endocrine insufficiency, pain and other symptoms seem to have a more complex pathogenesis independent of imaging pathology.

Chronic pancreatitis

PURPOSE OF REVIEW

We review selected important clinical observations reported in 2012.

RECENT FINDINGS

Celiac disease is a risk factor for pancreatitis. Patients with recurrent acute pancreatitis likely have chronic pancreatitis, do not benefit from pancreatic sphincterotomy, and may not benefit from biliary sphincterotomy. Analysis of endoscopic ultrasonography (EUS) images with an artificial neural network (ANN) program may improve chronic pancreatitis diagnosis compared with clinical interpretation of images. In a multicenter, randomized controlled trial of chronic pancreatitis patients, 90 000 USP U of pancreatin with meals decreased fat malabsorption compared with placebo. Detection of visceral pain in chronic pancreatitis predicts pain relief from various treatments, but nonvisceral pain due to altered central pain processing may respond to agents such as pregabalin. Predictors of surgical pain relief include onset of symptoms less than 3 years and preoperatively no opioid use and less than five endoscopic procedures. Total pancreatectomy for presumed painful chronic pancreatitis remains controversial.

SUMMARY

Celiacs are at risk for pancreatitis. The diagnosis of chronic pancreatitis may be enhanced by ANN analysis of EUS imaging. Treatment of fat malabsorption requires 90,000 USP U of lipase with meals. Relief of pain from organ directed treatment of chronic pancreatitis may depend upon timing of interventions and whether pain is visceral or nonvisceral.