Editorial
Copyright ©The Author(s) 2016. Published by Baishideng Publishing Group Inc. All rights reserved.
World J Gastroenterol. Jul 28, 2016; 22(28): 6335-6344
Published online Jul 28, 2016. doi: 10.3748/wjg.v22.i28.6335
Management of acute pancreatitis in Japan: Analysis of nationwide epidemiological survey
Shin Hamada, Atsushi Masamune, Tooru Shimosegawa
Shin Hamada, Atsushi Masamune, Tooru Shimosegawa, Division of Gastroenterology, Tohoku University Graduate School of Medicine, Sendai 980-8574, Japan
Author contributions: Hamada S and Masamune A contributed equally to this work; Hamada S and Masamune A designed the study and conducted the analysis; Masamune A and Shimosegawa T obtained the funding and directed the survey; Hamada S and Masamune A wrote the paper; and Shimosegawa T critically revised the manuscript for important intellectual content.
Supported by the Smoking Research Foundation to Masamune A.
Conflict-of-interest statement: The authors declare no conflict of interest.
Open-Access: This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
Correspondence to: Atsushi Masamune, MD, PhD, Associate Professor, Division of Gastroenterology, Tohoku University Graduate School of Medicine, 1-1 Seiryo-machi, Aoba-ku, Sendai 980-8574, Japan. amasamune@med.tohoku.ac.jp
Telephone: +81-22-7177172 Fax: +81-22-7177177
Received: April 14, 2016
Peer-review started: April 18, 2016
First decision: May 12, 2016
Revised: May 22, 2016
Accepted: June 13, 2016
Article in press: June 13, 2016
Published online: July 28, 2016
Abstract

Acute pancreatitis (AP) is an acute inflammatory disease of the exocrine pancreas. In Japan, nationwide epidemiological surveys have been conducted every 4 to 5 years by the Research Committee of Intractable Pancreatic Diseases, under the support of the Ministry of Health, Labour, and Welfare of Japan. We reviewed the results of the nationwide surveys focusing on the severity assessment and changes in the therapeutic strategy for walled-off necrosis. The severity assessment system currently used in Japan consists of 9 prognostic factors and the imaging grade on contrast-enhanced computed tomography. By univariate analysis, all of the 9 prognostic factors were associated with AP-related death. A multivariate analysis identified 4 out of the 9 prognostic factors (base excess or shock, renal failure, systemic inflammatory response syndrome criteria, and age) that were associated with AP-related death. Receiver-operating characteristics curve analysis showed that the area under the curve was 0.82 for these 4 prognostic factors and 0.84 for the 9 prognostic factors, suggesting the comparable utility of these 4 factors in the severity assessment. We also examined the temporal changes in treatment strategy for walled-off necrosis in Japan according to the 2003, 2007, and 2011 surveys. Step-up approaches and less-invasive endoscopic therapies were uncommon in 2003 and 2007, but became popular in 2011. Mortality has been decreasing in patients who require intervention for walled-off necrosis. In conclusion, the nationwide survey revealed the comparable utility of 4 prognostic factors in the severity assessment and the increased use of less-invasive, step-up approaches with improved clinical outcomes in the management of walled-off necrosis.

Keywords: Endoscopic necrosectomy, Diagnostic criteria, Epidemiology, Pancreatic pseudocyst, Systemic inflammatory response syndrome, Step-up approach, Walled-off necrosis

Core tip: We analyzed the results of nationwide epidemiological surveys of acute pancreatitis in Japan to clarify the utility of the prognostic factor scores in the severity assessment and the trend in the treatment of walled-off necrosis. Among the 9 prognostic factors, 4 factors including base excess or shock, renal failure, systemic inflammatory response syndrome criteria, and age were associated with mortality by multivariate analysis. Receiver operating characteristics curve analysis demonstrated the comparable utility of these 4 factors to the 9 factors in the severity assessment. Less-invasive, step-up approaches with improved clinical outcomes have become popular in the management of walled-off necrosis.