Hiroaki Yamato

Hakodate Municipal Hospital, Hokodate, Hokkaidō, Japan

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Publications (30)96.13 Total impact

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    ABSTRACT: Background and Objective: Antispasmodic drugs (ADs) have been used to reduce examination time or improve the quality of gastrointestinal endoscopy, although the practice is controversial. No evidence about the effi cacy of AD for endoscopic ultrasonography/EUS-guided fi ne-needle aspiration (EUS/EUS-FNA) is available. This study was aimed to evaluate the effi cacy of AD in EUS/EUS-FNA. Patients and Methods: A total of 400 patients with pancreaticobiliary, peripancreatic, or peribiliary disease or disorder undergoing EUS/EUS-FNA were prospectively and evenly randomized to undergo EUS/EUS-FNA with AD (w-AD) or without AD (w/o-AD). The primary endpoint was total EUS/EUS-FNA examination time. The secondary endpoints were visual analogue scale (VAS) scores of endoscopists (patient body motion, gastrointestinal peristalsis, and accomplishment of the purpose) and patients (pain, discomfort, and willingness to undergo re-examination), vital sign changes, adverse events, and sedative dose. Results: Two hundred patients in the w-AD group and 197 patients in the w/o-AD group were ultimately analyzed. The total examination time was similar between the groups (2299 ± 937 vs. 2259 ± 1019 s). The difference in total examination time from w/o-AD group to w-AD group was −40 s (95% confi dence interval, −234-153 s), which was within the noninferiority margin. No statistical differences were observed in endoscopist and patient VAS scores, changes in vital signs, adverse events, or total sedative dose other than fentanyl between the groups. Conclusion: EUS/EUS-FNA can be effectively and safely performed w/o-AD. Further, randomized controlled trials on EUS/EUS-FNA in various disease entities may be required to confi rm the results of this study (UMIN000008047).
    ENDOSCOPIC ULTRASOUND. 07/2014; 3(3):2014.
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    ABSTRACT: The prognosis for patients diagnosed with advanced colorectal cancer with liver metastases is poor. Chemotherapy should be administered with caution in such patients because of complications due to severe liver dysfunction. We report here the successful management of a case of advanced sigmoid colon cancer, with icterus due to severe liver metastases, treated with cetuximab as first-line therapy. A 72-year-old man presented at our institution with complaints of severe general fatigue, tarry stools, and abdominal distention. He was diagnosed with advanced sigmoid colon cancer with multiple liver metastases. Clinical examination revealed the presence of ascites. The patient had an Eastern Cooperative Oncology Group(ECOG) performance status(PS)score of 3. A biopsy specimen of the primary tumor showed well-moderately differentiated adenocarcinoma without KRAS mutation. He was diagnosed with advanced sigmoid colon cancer with multiple hepatic metastases. Cetuximab monotherapy was initiated as first-line treatment. After 4 courses of cetuximab monotherapy, results of laboratory tests showed an improvement, and a computed tomography(CT)scan revealed a regression in the size of the liver metastases. Because the results of liver function tests and the ECOG PS scores improved, we initiated combination chemotherapy with 5-fluorouracil, Leucovorin, oxaliplatin(FOLFOX), and cetuximab. This regimen was well tolerated up to 14 courses, during which the only adverse reaction reported was a rash of grade 2 toxicity. Thereafter, disease progression in the form of liver metastases resulted in a change in the combination therapy to irinotecan and S-1(IRIS)as second-line chemotherapy. Thereafter, irinotecan and panitumumab were administered as third-line therapy. The patient continued chemotherapy on an outpatient basis; however, he died due to disease progression 18 months after his first visit.
    Gan to kagaku ryoho. Cancer & chemotherapy 07/2014; 41(7):897-900.
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    ABSTRACT: Endoscopic ultrasound (EUS) and endoscopic retrograde cholangiopancreatography (ERCP) are essential for diagnosing and treating pancreatobiliary diseases. Single-session EUS and ERCP are considered to be essential in reducing the duration of hospital stays; however, complications are a primary concern. The aim of this study was to evaluate the safety and efficacy of single-session EUS and ERCP. Sixty-eight patients underwent single-session EUS and ERCP at a tertiary referral center between June 2008 and December 2012. We retrospectively reviewed patient data from a prospectively maintained EUS-ERCP database and evaluated the procedural characteristics and complications. Thirty-eight patients (56%) underwent diagnostic EUS, and 30 patients (44%) underwent EUS fine-needle aspiration, which had an overall accuracy of 100%. Sixty patients (89%) underwent therapeutic ERCP, whereas the remaining eight procedures were diagnostic. Thirteen patients underwent biliary stone extraction, and 48 underwent biliary drainage. The median total procedural time was 75 minutes. Complications were observed in seven patients (10%). Six complications were post-ERCP pancreatitis, which were resolved using conservative management. One patient developed Mallory-Weiss syndrome, which required endoscopic hemostasis. No sedation-related cardiopulmonary complications were observed. Single-session EUS and ERCP provided accurate diagnosis and effective management with a minimal complication rate.
    Gut and Liver 05/2014; 8(3):329-32.
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    ABSTRACT: To evaluate the safety and diagnostic accuracy of endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA) in a cohort of pancreatic cancer patients. Of 213 patients with pancreatic cancer evaluated between April 2007 and August 2011, 82 were thought to have resectable pancreatic cancer on the basis of cross-sectional imaging findings. Of these, 54 underwent EUS-FNA before surgery (FNA+ group) and 28 underwent surgery without preoperative EUS-FNA (FNA- group). All 54 lesions were visible on EUS, and all 54 attempts at FNA were technically successful. The diagnostic accuracy according to cytology and histology findings was 98.1% (53/54) and 77.8% (42/54), respectively, and the total accuracy was 98.1% (53/54). One patient developed mild pancreatitis after EUS-FNA but was successfully treated by conservative therapy. No severe complications occurred after EUS-FNA. In the FNA+ and FNA- groups, the median relapse-free survival (RFS) was 742 and 265 d, respectively (P = 0.0099), and the median overall survival (OS) was 1042 and 557 d, respectively (P = 0.0071). RFS and OS were therefore not inferior in the FNA+ group. These data indicate that the use of EUS-FNA did not influence RFS or OS, nor did it increase the risk of peritoneal recurrence. In patients with resectable pancreatic cancer, preoperative EUS-FNA is a safe and accurate diagnostic method.
    World Journal of Gastroenterology 04/2014; 20(13):3620-7. · 2.55 Impact Factor
  • Gastrointestinal endoscopy 01/2014; · 6.71 Impact Factor
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    ABSTRACT: Schwannomas are peripheral nerve tumors that are typically solitary and benign. Their diagnosis is largely based on surgically resected specimens. Recently, a number of case reports have indicated that retroperitoneal schwannomas could be diagnosed with endoscopic ultrasound-guided fine-needle aspiration (EUS-FNA). We report the diagnosis of three cases of schwannoma using EUS-FNA. Subjects were two males and one female, ages 22, 40, and 46 years, respectively, all of whom were symptom-free. Imaging findings showed well-circumscribed round tumors. However, as the tumors could not be diagnosed using these findings alone, EUS-FNA was performed. Hematoxylin-eosin staining of the resulting tissue fragments revealed bland spindle cells with nuclear palisading. There was no disparity in nuclear sizes. Immunostaining revealed S-100 protein positivity and all cases were diagnosed as schwannomas. Ki-67 indexes were 3%-15%, 2%-3%, and 3%, respectively. No case showed any signs of malignancy. As most schwannomas are benign tumors and seldom become malignant, we observed these patients without therapy. All tumors demonstrated no enlargement and no change in characteristics. Schwannomas are almost always benign and can be observed following diagnosis by EUS-FNA.
    World Journal of Gastroenterology 08/2011; 17(29):3459-64. · 2.55 Impact Factor
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    ABSTRACT: The controversy over whether and how to perform preoperative biliary drainage (PBD) in patients with hilar cholangiocarcinoma (HCA) remains unsettled. Arguments against PBD before pancreatoduodenectomy have recently been gaining momentum. However, the complication-related mortality rate is as high as 10% for patients with HCA who have undergone major liver resection, and liver failure is a major cause of postoperative death. This suggests the need for PBD to treat jaundice in HCA patients scheduled for major surgical resection of the liver and that major surgery should be performed only after the recovery of hepatic function. No definite criteria or guidelines outlining indications for PBD are currently available. In patients with HCA, PBD may be performed by either percutaneous transhepatic biliary drainage (PTBD) or endoscopic biliary drainage (EBD). No consensus, however, has been reached regarding which drainage method is more appropriate. No reported study has compared the effectiveness of PTBD, endoscopic biliary stenting (EBS), and endoscopic nasobiliary drainage (ENBD) in patients with HCA. This review summarizes the results of our study comparing the three methods and outlines the preoperative endoscopic management of segmental cholangitis (SC) in HCA patients undergoing PBD.
    Journal of hepato-biliary-pancreatic sciences. 06/2011; 18(5):630-5.
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    ABSTRACT: Endoscopic retrograde cholangiopancreatography (ERCP) and related procedures can cause abdominal pain and discomfort. Two clinical trials have indicated, using the visual analogue scale (VAS) score, that CO(2) insufflation during ERCP ameliorates the suffering of patients without complications, compared with air insufflation. However, differences in patient suffering between CO(2) and air insufflation after ERCP under deep conscious sedation have not been reported. We focused on the gas volume score (GVS) as an objective indicator of gas volume, and designed a multicenter, prospective, double-blind, randomized, controlled study with CO(2) and air insufflation during ERCP. Between March 2010 and August 2010, 80 patients who required ERCP were enrolled and evenly randomized to receive CO(2) insufflation (CO(2) group) or air insufflation (air group). ERCP and related procedures were performed under deep conscious sedation with fentanyl citrate or pethidine and midazolam or diazepam. The GVS was evaluated as the primary endpoint in addition to the VAS score as the secondary endpoint. The GVS after ERCP and related procedures in the CO(2) group was significantly lower than that in the air group (0.14 ± 0.06 vs. 0.31 ± 0.11, P < 0.01), as well as the rate of increase in GVS ([GVS after - GVS before]/[GVS before ERCP and related procedures] × 100) (3.8 ± 5.9 vs. 21 ± 11.1%, P < 0.01). VAS scores 3 and 24 h after ERCP and related procedures were comparable between the CO(2) and air groups for abdominal pain, abdominal distension, and nausea. Additionally, VAS scores were not correlated with the GVS. CO(2) insufflation during ERCP reduces GVS (bowel gas volume) but not the VAS score of suffering compared with air insufflation. Deep and sufficient sedation during ERCP and related procedures is important for the palliation of patients' pain and discomfort.
    Surgical Endoscopy 06/2011; 25(12):3784-90. · 3.43 Impact Factor
  • Endoscopy 03/2011; 43 Suppl 2 UCTN:E98-9. · 5.74 Impact Factor
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    ABSTRACT: Controversy exists over the preferred technique of preoperative biliary drainage (PBD) in patients with hilar cholangiocarcinoma (HCA). The goal of this retrospective study was to identify the preferred technique of PBD for HCA. A total of 128 consecutive patients with HCA diagnosed between September 1999 and December 2009 who underwent PBD were included in this study. The study compared outcomes of endoscopic nasobiliary drainage (ENBD), endoscopic biliary stenting (EBS), and percutaneous transhepatic biliary drainage (PTBD) in patients with HCA. There were no significant differences in preoperative laboratory data, rates of major hepatectomy, or decompression periods among the 3 groups. Complications were significantly more frequent in the EBS group compared with either the ENBD or PTBD group (p < 0.05). Drainage tube occlusion with cholangitis was significantly more common in the EBS group compared with either the ENBD or PTBD group (p < 0.0001). Patients in the PTBD group experienced serious complications including vascular injury (8%) and cancer dissemination (4%). Patients in the ENBD and EBS groups had mild post-endoscopic retrograde cholangiopancreatography pancreatitis (5%). Conversion procedures were significantly more common in the EBS group compared with the ENBD and PTBD groups (p < 0.05). There was no significant difference in postsurgical morbidity or mortality among the 3 groups. Drainage tube occlusion with cholangitis was a frequent complication associated with EBS. PTBD was associated with serious complications such as vascular injury and cancer dissemination. ENBD was found to be the most suitable method for initial PBD management in patients with HCA.
    Journal of Gastroenterology 02/2011; 46(2):242-8. · 3.79 Impact Factor
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    ABSTRACT: The poly(ADP-ribose) polymerases (PARPs) participate in many biological and pathological processes. Here we report that the PARP-13 shorter isoform (ZAPS), rather than the full-length protein (ZAP), was selectively induced by 5'-triphosphate-modified RNA (3pRNA) and functioned as a potent stimulator of interferon responses in human cells mediated by the RNA helicase RIG-I. ZAPS associated with RIG-I to promote the oligomerization and ATPase activity of RIG-I, which led to robust activation of IRF3 and NF-κB transcription factors. Disruption of the gene encoding ZAPS resulted in impaired induction of interferon-α (IFN-α), IFN-β and other cytokines after viral infection. These results indicate that ZAPS is a key regulator of RIG-I signaling during the innate antiviral immune response, which suggests its possible use as a therapeutic target for viral control.
    Nature Immunology 01/2011; 12(1):37-44. · 26.20 Impact Factor
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    ABSTRACT: Autoimmune pancreatitis is commonly associated with immunoglobulin (Ig) G4-related sclerosing cholangitis (IgG4-SC). The discrimination between IgG4-SC and pancreatobiliary malignancies or primary sclerosing cholangitis (PSC) is now an important issue. The present study was carried out to examine the usefulness of endoscopic biopsies from Vater's ampulla and the bile duct to diagnose IgG4-SC. The present study included 29 IgG4-SC patients (26 with both pancreatitis and cholangitis, and 3 with cholangitis only), 6 PSC patients, and 27 pancreatobiliary carcinoma patients. All patients underwent endoscopic biopsies from Vater's ampulla and the common bile duct. Biopsied specimens were histologically examined using immunostaining for IgG4. For the ampullary and bile duct biopsies, the IgG4-SC samples had a significantly greater number of IgG4-positive plasma cells than the PSC or pancreatobiliary carcinoma specimens. In addition, bile duct biopsies from five patients (17%) with IgG4-SC showed diffuse inflammatory cell infiltration with irregular fibrosis corresponding to the histological features of lymphoplasmacytic sclerosing pancreatocholangitis. Based on the threshold of 10 IgG4-positive plasma cells per high power field, the diagnostic rates of the ampullar and bile duct biopsies were both 52% (15/29 cases). Twenty-one patients (72%) had more than 10 IgG4-positive plasma cells in at least one biopsy. The bile duct biopsy was significantly valuable for IgG4-SC patients with swelling of the pancreatic head. The present study suggested that ampullar and bile duct biopsies are useful for diagnosing IgG4-SC.
    Journal of Gastroenterology and Hepatology 10/2010; 25(10):1648-55. · 3.33 Impact Factor
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    ABSTRACT: Background and study aims: Localized-type bile duct carcinoma (LBDC) is often accompanied by extensive intraepithelial tumor spread (ITS) ≥2 cm which makes radical resection more difficult. This retrospective case review compared the diagnostic accuracy of endoscopic retrograde cholangiography (ERC) and peroral cholangioscopy (POCS) to detect ITS beyond the visible LBDCs. Patients and methods: Forty-four consecutive LBDC patients diagnosed between April 2004 to October 2008 who underwent radical resection with histopathological analysis were included in this study. Extensive ITS was found histopathologically in one-third of the cases (32%). The outcome parameters were the presence or absence of extensive ITS and the extent of extensive ITS proximal and distal to the main tumor. Results: It was not possible to pass the cholangioscopic through the tumor sites in 6 cases. ERC correctly identified the presence of extensive ITS in 11/14 cases and did not yield any false-positive results. The three ERC-negative cases were all correctly identified by POCS plus biopsy since the cholangioscope could be passed in all three cases. The extent of extensive ITS was correctly diagnosed by ERC alone, ERC with POCS, and ERC with POCS plus mapping biopsy in 22%, 77%, and 100% of cases, respectively. Conclusions: The presence of extensive ITS could be correctly detected in 80% of cases by ERC alone. POCS with mapping biopsy provided perfect diagnostic accuracy of not only the presence/absence but also the extent of extensive ITS. However, POCS has the limitation that the cholangioscope cannot be passed through the tumor sites in approximately 15% of cases.
    Endoscopy 10/2009; · 5.74 Impact Factor
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    ABSTRACT: Pancreatic carcinoma associated with portal vein tumor thrombus (PVTT) is rare. Here, we report three cases of resected pancreatic carcinoma associated with PVTT. In all three cases, preoperative images obtained using computed tomography and endoscopic ultrasonography revealed a tumor thrombus in the portal vein, which was connected to an irregular mass in the pancreas. All cases underwent surgical resection of the primary lesion and the PVTT. The pathological diagnoses of the tumors were two cases of tubular adenocarcinoma and one case of nonfunctioning endocrine carcinoma. We also retrospectively examined other patients who underwent surgical excision with portal vein resection.
    Internal Medicine 02/2009; 48(3):143-50. · 0.97 Impact Factor
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    ABSTRACT: We had three cases of pancreatic groove carcinoma. All cases developed obstructive jaundice. Duodenoscopy showed stenosis of the second portion of the duodenum in every case. Thus, endoscopic bile duct drainage could not be performed in two cases. CT revealed a mass between the duodenum and head of the pancreas, which was not well-defined by contrast-enhancement. Endoscopic ultrasonography revealed a hypoechoic mass which was adjacent to the common bile duct and duodenum in the pancreas head in all cases. Therefore, we could diagnose pancreatic groove carcinoma.
    Nippon Shokakibyo Gakkai zasshi The Japanese journal of gastro-enterology 08/2008; 105(7):1061-9.
  • Gastrointestinal endoscopy 07/2008; 67(7):1170-1; discussion 1172. · 6.71 Impact Factor
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    ABSTRACT: A 68-year-old woman with a history of renal cell carcinoma (RCC) resected curatively 12 years previously was admitted to our department for scrutiny of pancreatic tumors. Various imaging studies demonstrated heterogeneously well-enhanced masses in the head and tail of the pancreas. The well-enhanced mass in the head of the pancreas was connected with the tumor thrombus in the portal vein. To differentially diagnose the multiple pancreatic lesions, we performed endoscopic ultrasound-guided fine-needle aspiration biopsy (EUS-FNAB). Histopathologic findings of the EUS-FNAB specimens were similar to those of the renal clear cell carcinoma previously resected. The patient underwent a surgical operation with segmental resection of the portal vein with the preoperative diagnosis of RCC metastasis to the pancreas with intraportal growth. Histopathological examination of the resected specimen revealed that the masses in the pancreas were multiple pancreatic metastases with intraportal tumor thrombus of RCC. The pancreas is a rare target for metastasis. This is a rare case of pancreatic metastasis from RCC with intraportal extension, and is the first preoperatively definitely diagnosed case using EUS-FNAB.
    Internal Medicine 02/2008; 47(22):1967-70. · 0.97 Impact Factor
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    ABSTRACT: Autoimmune pancreatitis (AIP) is a new category of pancreatic diseases. AIP associated with pseudocysts is rare; only 8 cases have been reported in the literature. A 63-year-old man was admitted to our department because of upper left abdominal pain and back pain. Various imaging studies demonstrated swelling of the tail of the pancreas with hemorrhagic pseudocysts. The patient underwent a surgical operation. A pancreatogram of the specimen revealed total occlusion of the main pancreatic duct in the tail of the pancreas. Histopathological examination revealed that it was AIP with hemorrhagic pseudocysts.
    Internal Medicine 02/2008; 47(7):603-8. · 0.97 Impact Factor
  • International Journal of Hematology 07/2006; 83(5):464-6. · 1.68 Impact Factor
  • Leukemia and Lymphoma 06/2006; 47(5):943-7. · 2.61 Impact Factor

Publication Stats

186 Citations
96.13 Total Impact Points

Institutions

  • 2004–2014
    • Hakodate Municipal Hospital
      Hokodate, Hokkaidō, Japan
  • 2008–2011
    • Hokkaido University
      • • Department of Gastroenterology and Hepatology
      • • Graduate School of Medicine
      Sapporo-shi, Hokkaido, Japan