Early chronic pancreatitis: A conceptual understanding

Early chronic pancreatitis: A conceptual understanding

Abstracts / Pancreatology 16 (2016) S1eS192 vasculature occasionally including superior mesenteric artery (SMA), celiac axis (CA) or common hepatic a...

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Abstracts / Pancreatology 16 (2016) S1eS192

vasculature occasionally including superior mesenteric artery (SMA), celiac axis (CA) or common hepatic artery (CHA). For pancreaticoduodenectomy specimen, axial slicing provides an overall assessment of the tumor relative to the ampulla, bile duct, and duodenum, and all of the pancreatic circumferential tissue margins. Especially, comprehensive assessments about margins can be performed accurately by comparing with axial CT images, even if mesenteric vasculature was preserved without concomitant resection. For distal pancreatectomy specimen, perpendicular slicing provides assessment of posterior peripancreatic margin which is contact to surface of adrenal, adventitia of CHA or CA. Oblique CT images of multi-planar reconstruction (MPR) matched to perpendicular slicing allow accurate margin assessment, even if major arteries or retroperitoneal organs was preserved. Histopathological review of resectability based on CT images is essential to refine decision of resectability in PDAC.

IC4-7. A new resectability definition for borderline resectable pancreatic cancer in general rules for the study of pancreatic cancer (Japan pancreas society 7th edition) Masashi Kishiwada, Shuji Isaji Department of Hepatobiliary Pancreatic and Transplant Surgery, Mie University School of Medicine, Japan Background: Resectability of pancreatic ductal adenocarcinoma (PDAC) is commonly defined as having the involvement of superior mesenteric vein (SMV)/portal vein (PV), superior mesenteric artery (SMA), celiac axis (CA) or common hepatic artery (CHA). In Japan, the evaluation of operation has been decided by the institution's criteria, the National Comprehensive Cancer Network (NCCN) guidelines and so on. The standardization of the resectability definition is necessary for PDAC because variations in definition cause confusion and are difficult for clinical use. For managing PDAC, surgical resection is the only potentially curative technique and R0 resection is a strong prognostic indicator for long-term patient survival. The NCCN have developed guidelines to define tumor resectability in PDAC, in order to improve patient selection for surgery and to identify the likelihood of an R0 resection. Using their criteria, PDAC is classified as resectable (R), borderline resectable (BR), locally unresectable (UR-LA), or metastatic (UR-M). BR-PDAC can be defined as one that increases the likelihood of an incomplete resection. A new resectability definition for PDAC on JPS: General rules for the study of pancreatic cancer on Japan pancreas society (JPS) proposed a new resectability definition since November 2015. As a result of having discussed by pancreatic surgeons, physicians, oncologists, endoscopists, radiologists, pathologist and anatomists, anatomical criteria based on pancreatic protocol MDCT has been developed as a new resectability definition without subjective factors such as the surgeons' skill and experience. As for the BR-PDAC, these includes two distinct categories of tumors influencing survival. JPS sub-classified into BR-PV (SMV/PV invasion alone) and BR-A (major arterial invasion). 1) BR-PV: No findings of abutment and invasion of the SMA, CA and CHA. Tumor abutment or invasion of the SMV/ PV of 180 degree or more, or occlusion of the SMV/PV not to exceed the inferior border of the duodenum. 2) BR-A: Tumor abutment or invasion of the SMA and/or CA less than 180 degree without showing stenosis or deformity. Tumor abutment or invasion of the CHA without showing tumor abutment or invasion of the proper hepatic artery and/or CA. Location of main tumor or variant artery anatomy are not considered. Conclusion: Using common definition for BR-PDAC, we hope treatment strategy and randomized control trials such as the neoadjuvant therapy (chemo/chemoradiation therapy) are planned in the near future.

IC5-KL1. Chronic pancreatitis: Call for adopting a mechanistic definition before establishing diagnostic criteria David Clement Whitcomb

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Division of Gastroenterology, Hepatology and Nutrition, Departments of Medicine, University of Pittsburgh, USA Chronic pancreatitis (CP) has been defined as “a continuing inflammatory disease of the pancreas, characterized by irreversible morphological change, and typically causing pain and/or permanent loss of function”. Genetic epidemiology studies demonstrate that CP is a group of complex gene-environment disorders with similar pathology. Thus, morphologic features are inadequate for early diagnosis, mechanistic classification or guiding effective therapies. To address this dilemma, a group of expert physician-scientists from the United States, India, Europe and Japan reviewed medical and scientific literature and clinical experiences. A proposal was made for a mechanistic definition of CP with two parts reflecting the essence of CP and the features of CP: ‘Chronic pancreatitis is a pathologic fibro-inflammatory syndrome of the pancreas in individuals with genetic, environmental and/or other risk factors who develop persistent pathologic responses to parenchymal injury or stress’ and “Common features of established and advanced CP include pancreatic atrophy, fibrosis, pain syndromes, duct distortion and strictures, calcifications, pancreatic exocrine dysfunction, pancreatic endocrine dysfunction, and dysplasia. Furthermore, the progressive stages of CP were defined as “At Risk”, “RP-RAP”, “Early CP”, “Established CP” and “End Stage CP”. Using this framework the pathogenic pathways (essence) and biomarkers (features) needed to distinguish CP from other disorders and define the difference between “Early CP” and “Established CP” should become explicit. Thus, “Early CP” can be defined by the presence of CP risk factors plus evidence of persistent disease activity, but without the features that define “established CP”. Furthermore, the essential features, and supporting features for “Established CP” must be defined to mark the point of transition from one state to another. Inclusion or exclusion of overlapping features such as “pancreatopathy”, “autoimmune pancreatitis”, “atrophy”, fatty pancreas, neoplasia, and effects of diabetes on the exocrine pancreas must also be considered.

IC5-1. Early chronic pancreatitis: A conceptual understanding Pramod Garg Gastroenterology, All India Institute of Medical Sciences, India From a conceptual point of view, any chronic disease must begin with subtle changes and progress over a period of time before manifesting with overt clinical features and a diagnosable state on standard investigations based on which its entity was primarily established. Chronic pancreatitis (CP) is diagnosed when a patient presents with recurrent or chronic abdominal pain and there are demonstrable pancreatic ductal abnormalities in the form of ductal irregularity, dilatation, stricture and/ or calculi. Of course, for the disease to reach that stage i.e. for it to be picked up by currently available investigations, it must have traveled through earlier stages in its evolution over a considerable period of time. In the case of CP, recurrent parenchymal injury with acinar cell loss, chronic inflammation and pathological fibrosis lead to gradually progressive morphological changes and functional loss. Our inability to diagnose CP in its earlier stage of development is largely due to the limitations of the currently available investigative modalities to correctly interpret the morphological and/or biochemical abnormalities in the evolutionary phase of the disease. The question, ‘does early CP exist?’ is irrelevant for CP, as we diagnose it, cannot develop de novo. Rather, how to diagnose early CP and what are the implications of diagnosing early CP are clinically relevant issues. Endoscopic ultrasonography (EUS) by virtue of its ability to visualize subtle parenchymal and ductal changes has proved to be a useful modality but suffers from somewhat limited specificity. Further refinement in diagnostic modalities based on a better understanding of the biochemical, metabolic, and/or structural changes during the early phase of CP might pave the way for accurate diagnosis. The implications for targeting the pathophysiological perturbations at that stage in the hope to halt the progression of the disease are not difficult to imagine.