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Featured researches published by Jun Ienaga.


Annals of Surgery | 2010

Predictors of the presence of concomitant invasive ductal carcinoma in intraductal papillary mucinous neoplasm of the pancreas

Thun Ingkakul; Yoshihiko Sadakari; Jun Ienaga; Norihiro Satoh; Shunichi Takahata; Masao Tanaka

Objective:Invasive ductal carcinoma (DC) of the pancreas arising as an independent lesion in association with intraductal papillary mucinous neoplasm (IPMN) has occasionally been reported. However, clinicopathological features related to the presence of DC in patients with IPMN remain largely unknown. The purpose of the present study was to determine the factors predicting the presence of concomitant DC in those with IPMN. Materials and Methods:We retrospectively reviewed the clinicopathological data of a consecutive series of 236 patients with IPMN treated by surgical resection or followed up at our institution between January 1987 and June 2008. In an attempt to identify predictors for the presence of DC, clinicopathological variables were compared between IPMN patients with concomitant DC and those without concomitant DC. Results:Of 236 patients with IPMN, concomitant DC was detected synchronously or metachronously in 22 patients (9.3%). All the 22 IPMNs were of branch duct type and histological grades of 12 resected IPMNs were adenoma(n = 8) and borderline (n = 4). Multivariate analysis revealed 2 significant predictive factors for the presence of DC in IPMN, including worsening diabetes mellitus (P < 0.001) and an abnormal serum CA 19–9 level (P = 0.024). Conclusion:In view of the high prevalence of DC careful inspection of the entire pancreatic gland is necessary for early detection of DC in patients with branch duct IPMNs, especially when worsening diabetes mellitus and an abnormal serum CA 19–9 level are manifested.


Pancreas | 2010

Cyst size indicates malignant transformation in branch duct intraductal papillary mucinous neoplasm of the pancreas without mural nodules.

Yoshihiko Sadakari; Jun Ienaga; Kiichiro Kobayashi; Yoshihiro Miyasaka; Shunichi Takahata; Masafumi Nakamura; Kazuhiro Mizumoto; Masao Tanaka

Objectives: In branch duct intraductal papillary mucinous neoplasm (IPMN) of the pancreas, the importance of the cyst size to predict malignancy is still controversial. Our aim was to elucidate the malignant potential of branch duct IPMN without mural nodules (flat branch duct IPMN). Methods: Seventy-three patients with flat branch duct IPMNs were studied in our institution. Results: There were 6 malignant IPMNs in this series, all of which were 30 mm or more in size, whereas there was no malignancy in IPMNs of less than 30 mm. Statistically significant predictors of malignancy were atypical cytological condition and main pancreatic duct (MPD) diameter of 5 mm or more. The cyst size of 30 mm or more tended to be associated with malignancy. The frequency of malignancy in flat branch duct IPMNs with the size of 30 mm or more and MPD diameter of less than 5 mm was 3.6%, whereas there were 5 malignant cases (26.3%) in flat branch duct IPMNs with the size of 30 mm or more and MPD diameter of 5 mm or more. Conclusions: We conclude that the size criteria (≥30 mm) to predict malignancy proposed in the international consensus guidelines is appropriate and resection or meticulous follow-up using cytological examination and MPD dilatation is needed in patients with flat branch duct IPMNs.


International Journal of Surgery Case Reports | 2016

Asymptomatic adenocarcinoma arising from a gastric duplication cyst: A case report

Akio Yamasaki; Hideya Onishi; Hirofumi Yamamoto; Jun Ienaga; Y. Nakafusa; Reiji Terasaka; Masafumi Nakamura

Highlights • Adenocarcinoma arising from a gastric duplication cyst is extremely rare.• This is the 2nd asymptomatic case in the English literature.• During our close observation of 4 years, malignant transformation had occurred from a gastric duplication cyst.• When morphological change appears, we strongly recommend surgical treatment without delay.


Journal of Hepato-biliary-pancreatic Surgery | 2009

Prevention of iatrogenic bile duct injuries in difficult laparoscopic cholecystectomies: is the naso‐biliary drain the answer?

Chandika A.H. Liyanage; Yoshihiko Sadakari; Hidehisa Kitada; Jun Ienaga; Reiko Tanabe; Shunichi Takahata; Toshinaga Nabae; Masao Tanaka

BACKGROUND Prevention of iatrogenic injuries is of paramount importance in difficult laparoscopic cholecystectomies (LC). The objective of this study was to analyze the effectiveness of cholangiography using a pre-inserted endoscopic naso-biliary drain (ENBD) for navigation during difficult cholecystectomies. METHODS The study design was a retrospective case analysis. In 508 patients who underwent LC in a tertiary referral university hospital from 1996 through 2007, difficult cholecystectomy was anticipated in 26 patients due to possibly aberrant biliary anatomy (four patients), unclear cystic duct anatomy during magnetic resonance cholangiopancreatography (MRCP) and/or endoscopic retrograde cholangiopancreatography (ERCP) (three patients), and acute cholecystitis (19 patients). An ENBD was inserted during ERCP prior to LC for cholangiography (ENBDC) to facilitate safe dissection during LC. Prevalence of biliary complications was assessed as the main outcome measurement. RESULTS The majority (68%) of the patients who underwent ENBDC had complicated cholecystitis. Advanced technical expertise was not required for insertion of an ENBD. In retrospect, ENBDC was useful in prevention of a possible catastrophe in 69% of cases. Open conversion was necessary in five patients and biliary complications occurred in five patients only in the non-ENBD group. There were no procedure-related complications. One limitation of the study was that it was not randomized and there was no comparison with patients without ENBDC. CONCLUSIONS ENBDC is a useful and safe tool in the prevention of iatrogenic bile duct injuries in LC.


Anticancer Research | 2016

A Feasibility Study of Neoadjuvant XELOX Without Radiotherapy for Locally Advanced Lower Rectal Cancer

Takashi Ueki; Tatsuya Manabe; Shigetaka Inoue; Jun Ienaga; Naoki Yamanaka; Takuya Egami; Mikimasa Ishikawa; Hiroyuki Konomi; Akashi Ikubo; Kinuko Nagayoshi; Masafumi Nakamura; Masao Tanaka


Pancreas | 2010

Case Report: Transgastric Pancreaticogastrostomy for Treatment of Chronic Pancreatitis

Kosuke Tsutsumi; Koji Yamaguchi; Norihiro Sato; Takaharu Yasui; Yoshihiko Sadakari; Jun Ienaga; Shunichi Takahata; Masafumi Nakamura; Shuji Shimizu; Masao Tanaka


Pancreas | 2010

Transgastric Pancreaticogastrostomy for the Treatment of Chronic Pancreatitis: A Case Report

Kosuke Tsutsumi; Koji Yamaguchi; Norihiro Sato; Takaharu Yasui; Yoshihiko Sadakari; Jun Ienaga; Shunichi Takahata; Masafumi Nakamura; Shuji Shimizu; Masao Tanaka


Suizo | 2009

Transgastric pancreaticogastrostomy for treatment of chronic pancreatitis

Kosuke Tsutsumi; Koji Yamaguchi; Norihiro Sato; Takaharu Yasui; Yoshihiko Sadakari; Jun Ienaga; Shunichi Takahata; Masafumi Nakamura; Shuji Shimizu; Masao Tanaka


Gastrointestinal Endoscopy | 2009

Preserved Gallbladder Prevents Recurrent Common Bile Duct Stones After Endoscopic Sphincterotomy

Shunichi Takahata; Kosuke Tsutsumi; Takaharu Yasui; Yoshihiko Sadakari; Jun Ienaga; Masao Tanaka


Journal of Surgical Research | 2008

QS28. Timing of Surgery in Patients With IPMN Under Follow Up: Does Changes in Diameter of Cystic Lesions Suggest Malignancy?

Yoshihiko Sadakari; Jun Ienaga; Reiko Tanabe; Norihiro Sato; Shunichi Takahata; Hiroki Toma; Toshinaga Nabae; Masafumi Nakamura; Koji Yamaguchi; Masao Tanaka

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