Itaru Oi

Tokyo Women's Medical University, Edo, Tōkyō, Japan

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Publications (47)88.18 Total impact

  • [Show abstract] [Hide abstract]
    ABSTRACT: The present study was undertaken to identify the clinicopathological differences between sclerosing cholangitis with autoimmune pancreatitis (SC-AIP) and primary sclerosing cholangitis (PSC). We retrospectively compared the clinical, cholangiographic, and liver biopsy findings between 24 cases of PSC and 24 cases of SC-AIP. Patient age at the time of diagnosis was significantly lower in the PSC group than in the SC-AIP group. The peripheral blood eosinophil count was significantly higher in the PSC group than in the SC-AIP group, but the serum IgG4 level was significantly higher in the SC-AIP group. Cholangiography revealed band-like strictures, beaded appearance, and pruned-tree appearance significantly more frequently in PSC, whereas segmental strictures and strictures of the distal third of the common bile duct were significantly more common in SC-AIP. Liver biopsy revealed fibrous obliterative cholangitis only in the PSC specimens. No advanced fibrous change corresponding to Ludwig's stages 3 and 4 was observed in any of the SC-AIP specimens. IgG4-positive plasma cell infiltration of the liver was significantly more severe in SC-AIP than in PSC. Subsequent cholangiography showed no improvement in any of the PSC cases, but all SC-AIP patients responded to steroid therapy, and improvement in the strictures was observed cholangio-graphically. Based on the differences between the patients' ages and blood chemistry, cholangiographic, and liver biopsy findings, SC-AIP should be differentiated from PSC.
    Journal of Gastroenterology 08/2007; 42(7):550-9. DOI:10.1007/s00535-007-2038-8 · 4.52 Impact Factor
  • Gastrointestinal Endoscopy 04/2007; 65(5). DOI:10.1016/j.gie.2007.03.042 · 5.37 Impact Factor
  • Gastrointestinal Endoscopy 04/2007; 65(5). DOI:10.1016/j.gie.2007.03.565 · 5.37 Impact Factor
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    ABSTRACT: Background: Nodular gastritis (NG) was considered a physiological change with little pathological significance, mostly in young women. In recent years, however, it has been often reported in patients with Helicobacter pylori (H. pylori) infection, or in patients with gastroduodenal ulcer/gastric cancer, suggesting possible clinical significance. Methods: From July 2003 to July 2006, 59 patients were diagnosed with NG among 32 404 patients examined endoscopically. The incidence of NG was evaluated in relation to age, sex, H. pylori infection status, symptoms leading to endoscopy, associated lesions in the upper digestive tract at the time of NG diagnosis, and existence of other systemic conditions. Results: The NG patients consisted of 13 out of 18 152 (0.07%) male patients and 46 out of 14 252 (0.32%) female patients, with a mean age of 45.3 ± 17.7 years. All 28 patients who were examined for H. pylori infection were positive. Endoscopic examination was performed for precordial pain and upper abdominal pain in 24 (40.7%) patients, symptoms of gastroesophageal reflux disease in eight (13.6%) patients, and symptoms of functional dyspepsia in six (10.2%) patients. NG was associated with duodenal ulcer in eight (13.6%) patients, hyperplastic gastric polyps in five (8.5%), gastric ulcer in one (1.7%), and gastric cancer in one (1.7%) patient. Conclusion: NG is a specific gastritis resulting from H. pylori infection that may be strongly associated with H. pylori-related lesions.
    Digestive Endoscopy 02/2007; 19(2):74 - 79. DOI:10.1111/j.1443-1661.2007.00693.x · 2.06 Impact Factor
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    ABSTRACT: Although a number of pathological studies using various names/synonyms for autoimmune pancreatitis (AIP) have been reported, they do not mention the pathological staging related to origin/pathogenesis. Here, we propose a pathological staging for AIP lesions. We histopathologically examined pancreatic tissue specimens of 31 AIP patients (14 pancreatectomized and 17 needle-biopsied materials) provided by 15 hospitals in Japan and studied the relevance of clinical manifestations to the pathological stage of AIP. Based on the presence or absence of acinar cells in AIP lesions, pancreatic tissue specimens were successfully divided into 20 cases in the early stage and 11 cases in the advanced stage, respectively. In the early stage, fibrosis was distributed in the interlobular and intralobular areas, admixed with acinar atrophy. Lymphoplasmacytic infiltration caused the narrowing of the ductal lumen and obliterative phlebitis. The common bile duct wall was also involved. In the advanced stage, the lesion was replaced by massive/extensive interlobular fibrosis with lymphoplasmacytic infiltrates to various degrees. Phlebitis was mild. Comparative analysis of clinical parameters between the early and advanced stages showed a significantly higher prevalence of jaundice and positive antinuclear antibodies in the early stage, and decreased serum lipase levels in the advanced stage. Autoimmune pancreatitis can be divided into early and advanced stages according to the presence or absence of acinar cells. Our pathological staging will facilitate understanding and evaluation of the clinical course in AIP.
    Pancreas 12/2006; 33(4):345-50. DOI:10.1097/01.mpa.0000235305.96486.f1 · 2.96 Impact Factor
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    ABSTRACT: The present study was undertaken to evaluate the prevalence of pancreatic and biliary tract tumors in pancreas divisum (PD). A retrospective single-center study was performed, and a total of 118 cases of complete PD and 7850 cases of fused pancreas were identified among the 8537 consecutive new endoscopic retrograde cholangiopancreatography (ERCP) examinations performed between 1980 and 2002. The prevalence of pancreatic cancer (PCA), intraductal papillary mucinous neoplasms (IPMNs), other pancreatic tumors, and biliary tract cancer in the patients with PD and the patients with a fused pancreas were compared. The prevalence of the pancreatic tumors in the PD patients was: PCA, 10%; IPMN, 5.1%; other pancreatic tumors, 2.5%. The prevalence of pancreatic tumors in the patients with a fused pancreas was: PCA, 4.8%; IPMN, 2.6%; and other pancreatic tumors, 1.1%. The prevalence of PCA was significantly higher in the patients with PD than in those with a fused pancreas (P = 0.008; OR, 2.24). The percentages of PD patients with PCA who had pancreatic-type pain and a serum pancreatic enzyme elevation were significantly higher than among the PD patients without PCA. The prevalence of biliary tract cancer was 0.8% in the PD group and 5.3% in the fused pancreas group, and it was significantly lower in PD than in fused pancreas (P = 0.031). The results of this study showed a significantly higher prevalence of PCA in PD than in fused pancreas. We concluded that patients with PD, especially patients presenting with pancreatic-type pain and pancreatic enzyme elevation, should be carefully followed up because of the risk of developing PCA.
    Journal of Gastroenterology 12/2006; 41(11):1088-93. DOI:10.1007/s00535-006-1893-z · 4.52 Impact Factor
  • Gastrointestinal Endoscopy 04/2006; 63(5). DOI:10.1016/j.gie.2006.03.668 · 5.37 Impact Factor
  • Gastrointestinal Endoscopy 04/2006; 63(5):AB313-AB313. DOI:10.1016/j.gie.2006.03.849 · 5.37 Impact Factor
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    ABSTRACT: Background: Gastric antral vascular ectasia (GAVE) is characterized by diffuse vasodilation mainly affecting the antrum and causes gastrointestinal hemorrhage. Argon plasma coagulation (APC) provides rapid coagulation of a wide region, and thus appears to be more useful than conventional methods for the treatment of extensive lesions with superficial oozing bleeding, such as GAVE. In this study, we evaluated the use of APC for GAVE. Methods: The study subjects were 22 patients with GAVE (10 men and 12 women, mean age 65.8 years, diffuse type (n = 19) and watermelon type (n = 3)) who developed gastrointestinal hemorrhage (melena, fall in hemoglobin (Hb, by ≥ 2.0 g/dL), or endoscopy-confirmed bleeding) and treated with APC. Endoscopic treatment was applied weekly, and considered successful if all detectable GAVE lesions were eradicated and the Hb stabilized without further transfusion. Clinical outcome was assessed. Results: The median total number of treatment sessions was four (range: 2–9 times), and the median observation period was 23.5 months. The cumulative recurrence-free rate was 49.7% after 1 year, 35.5% after 2 years, and 35.5% after 3 years. The survival rates after treatment were 94.4, 75.8 and 64.9% at 1, 2, and 3 years, respectively. No complications of APC were observed. Conclusion: APC appears to be effective for temporary control of hemorrhage and anemia due to GAVE, but is not always effective over the long term. For proper management of GAVE, drug therapy, blood transfusion and control of the underlying disease are necessary in addition to achieving hemostasis temporarily by APC.
    Digestive Endoscopy 02/2006; 18(2):128 - 133. DOI:10.1111/j.1443-1661.2006.00592.x · 2.06 Impact Factor
  • 01/2006; 68(2):104-105. DOI:10.11641/pde.68.2_104
  • 01/2006; 68(2):77-81. DOI:10.11641/pde.68.2_77
  • Pancreas 11/2005; 31(4):459-460. DOI:10.1097/01.mpa.0000193731.19415.72 · 2.96 Impact Factor
  • Pancreas 07/2005; 31(1). DOI:10.1097/01.mpa.0000164450.61641.f6 · 2.96 Impact Factor
  • Gastrointestinal Endoscopy 04/2005; 61(5). DOI:10.1016/S0016-5107(05)01115-6 · 5.37 Impact Factor
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    ABSTRACT: Autoimmune pancreatitis (AIP) is a unique clinical entity that has been recently proposed, and it is frequently associated with bile duct stricture. The aim of this study was to investigate the pathophysiology of the biliary tract involvement in patients with AIP. We evaluated the clinicopathologic findings in 16 patients with AIP. Surgical resection was performed in 7 of the patients because of suspicion of a pancreatic tumor; 8 of the other patients were treated with oral prednisolone (PSL) therapy, and the remaining patient was observed clinically and not treated. The pancreas, bile duct, and gallbladder in the surgical cases were examined histologically and immunohistochemically. We also assessed the clinical manifestations and diagnostic imaging findings before and after oral PSL therapy in the 8 patients treated with PSL. Stricture of the extrahepatic bile duct was detected in 88% (14/16) of the patients. Thickening of the bile duct wall was detected in 94% (15/16), and thickening of the gallbladder wall was observed in 56% (9/16). Histologically, the bile duct and gallbladder wall were characterized by diffuse lymphoplasmacytic infiltration and marked interstitial fibrosis. Immunohistochemically, the diffusely infiltrating cells consisted of predominantly CD8- or CD4-positive T lymphocytes and IgG4-positive plasma cells. These findings were the same as in the inflammatory process that was observed in the pancreas. After oral PSL therapy, the pancreatic enlargement and irregular narrowing of the main pancreatic duct improved to almost their normal size in all 8 patients; however, stricture of the extrahepatic bile duct persisted in 4 of the patients (57%, 4/7) in whom it was detected before PSL therapy. Based on the pathophysiologic and histologic findings and the response to PSL therapy, the biliary involvement in AIP developed by the same mechanism as the pancreatitis. CD8- and CD4-positive lymphocytes and IgG4-positive plasma cells may play an important role in the pathogenesis of AIP.
    Pancreas 02/2005; 30(1):76-82. · 2.96 Impact Factor
  • 01/2005; 67(2):84-85. DOI:10.11641/pde.67.2_84
  • 01/2005; 67(2):108-109. DOI:10.11641/pde.67.2_108
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    ABSTRACT: Objective: The aim of the present study was to assess the usefulness of endoscopic ultrasonography (EUS) for evaluating the efficacy of neoadjuvant therapy for advanced esophageal carcinoma based on the Response Evaluation Criteria in Solid Tumors (RECIST). Patients and Methods: Sixty-two patients with advanced esophageal carcinoma underwent surgical resection after neoadjuvant therapy. The maximal tumor thickness was measured by EUS before and after neoadjuvant therapy, and the percent reduction was compared with the pathological response. Based on the RECIST, PD-SD (progressive disease-stable disease) was defined as < 30% reduction of tumor thickness on EUS, PR (partial response) as ≥ 30% reduction of tumor thickness, and CR (complete response) as no detectable tumor (100%). Results: The percent reduction of the thickness of Grade 0–1, Grade 2 and Grade 3 tumor was 11.5 ± 21.0%, 48.2 ± 17.0% and 74.9 ± 21.1%, respectively. There were significant differences in the extent of reduction among the three groups. Based on the RECIST, 80% of Grade 0–1 cases, 91% of Grade 2 cases and 22% of Grade 3 cases were PD-SD, PR, and CR according to EUS, respectively. EUS correctly identified 80% of non-responders and 94% of responders. Conclusions: The percentage reduction of tumor thickness on EUS closely reflected the pathological evaluation. EUS evaluation based on the RECIST seems to be useful for monitoring neoadjuvant therapy in patients with esophageal carcinoma.
    Digestive Endoscopy 12/2004; 17(1):59 - 63. DOI:10.1111/j.1443-1661.2005.00458.x · 2.06 Impact Factor
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    ABSTRACT: A standard treatment for esophageal squamous cell carcinoma (SCC) with submucosal invasion is considered to be radical resection at present. In this study, we evaluated the efficacy of multimodality treatments with endoscopic mucosal resection (EMR) of esophageal SCC with submucosal invasion. Eighteen cases of SCC with submucosal invasion were treated with EMR. Lymphatic invasion was found in 11 cases (67%), and there were no cases of blood vessel invasion. EMR was performed prior to any other treatment. Chemotherapy and/or radiotherapy were added if indicated by the histopathological features. There were no cases of local recurrence. Lymph-node recurrence was detected in 1 case treated with EMR alone. There were no cases of cancer death. The overall survival rate was 83% in all patients. Multimodality treatments with EMR were effective in treating esophageal SCC with submucosal invasion.
    Surgical Endoscopy 10/2003; 17(9):1429-33. DOI:10.1007/s00464-002-8708-y · 3.26 Impact Factor
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    ABSTRACT: Background:  Esophageal varices are treated by endoscopic variceal ligation or sclerotherapy, but the indications for each procedure are not standardized. The present study was designed to determine the indication of endoscopic variceal ligation based on vascular pattern classified by 3-dimensional endoscopic ultrasonography (3-D-EUS).Methods:  The pattern of variceal blood flow detected on 3-D images was classified into type 1 (cardial-inflow without paraesophageal veins), type 2 (cardial-inflow with paraesophageal veins), type 3 (azygos-perforating pattern) and type 4 (complex pattern). 3-D-EUS was performed in 89 patients with esophageal varices. Subsequently, ligation was performed in 44 patients, while sclerotherapy with 5% ethanolamine oleate was applied in 45 patients in a prospective randomized trial. Clinical outcome was assessed.Results:  Based on the 3-D-EUS data, 41 patients (46.1%) were classified as type 1, 12 (13.5%) as type 2, seven (7.9%) as type 3 and 29 patients (32.6%) as type 4. The cumulative recurrence-free probability at 24 months after treatment was 28.9% for ligation versus 71.1% for sclerotherapy (P < 0.05) in type 1, while the respective probabilities were 72.9% versus 50.0% (NS) for type 2 varices, 100% versus 100% (NS) for type 3 varices and 61.9% versus 64.8% (NS) for type 4 varices.Conclusions:  Classification of the vascular pattern of esophageal varices by 3-D-EUS enabled us to clarify the criteria for selection of endoscopic procedure. Ligation is indicated for patients who have collaterals, such as paraesophageal veins running parallel to the varices, as the blood flow can be diverted to these blood vessels and controlled by localized ligation.
    Digestive Endoscopy 09/2003; 15(4):289 - 297. DOI:10.1046/j.1443-1661.2003.t01-2-00262.x · 2.06 Impact Factor

Publication Stats

299 Citations
88.18 Total Impact Points


  • 2003–2007
    • Tokyo Women's Medical University
      • Institute of Gastroenterology
      Edo, Tōkyō, Japan
  • 1976
    • University of Arkansas at Little Rock
      Little Rock, Arkansas, United States