Magnetic resonance elastography increases usefulness and safety of non-invasive screening for esophageal varices.

BACKGROUND AND AIMS: The Baveno VI criteria enable non-invasive screening for esophageal varices. However, these criteria were established based on studies examining a large proportion of patients with viral hepatitis and relatively few patients with non-alcoholic fatty liver disease (NAFLD). Furthermore, because vibration-controlled transient elastography (VCTE) has a high incidence of measurement error, improved criteria are needed. We aimed to develop criteria based on magnetic resonance elastography (MRE) even among patients with NAFLD. METHODS: We performed a cross-sectional analysis of patients who had undergone MRE and/or VCTE as well as an esophagogastroduodenoscopy. The patients were classified as having either a low risk or a high risk of varices. The optimal cut-offs for ruling out esophageal varices were calculated for the MRE and VCTE liver stiffness measurement (LSM), the platelet count in an estimation cohort, and the cut-offs were then evaluated using validation cohorts composed of patients who had undergone only MRE or VCTE. RESULTS: The study included 627 patients (39% with NAFLD). The optimal cut-off values for the MRE-LSM and the platelet count were 4.2 kPa and 18.0 × 104 /µL, respectively. An MRE-LSM of 4.2 kPa plus a platelet count of 18.0 × 104 /µL had a negative predictive value of 1.00 for both low-risk plus high-risk varices as well as for high-risk varices in a validation cohort, enabling the presence of varices to be ruled out. CONCLUSIONS: Magnetic resonance elastography might enable a safer avoidance of screening endoscopy, with a smaller measurement error, among patient populations with a high prevalence of NAFLD.

Pulmonary edema after laparoscopic hepatectomy in a patient with Budd-Chiari syndrome-associated hepatocellular carcinoma.

An 84-year-old man diagnosed with Budd-Chiari syndrome (BCS) developed a 20-mm hepatocellular carcinoma. We performed laparoscopic hepatectomy without complications, but the patient's percutaneous oxygen saturation gradually worsened and pulmonary edema was detected 50 minutes after extubation. He was subsequently re-intubated and received diuretic therapy. He was discharged on postoperative day 32. Patients with severe BCS have been reported to have an expanded plasma volume. In addition, pneumoperitoneum during laparoscopic surgery has been reported to decrease the venous flow in the portal vein and/or renal vein, the collateral pathways in BCS. The cause of pulmonary edema in the present case may have involved increased venous return following decompression of pneumoperitoneum pressure under the state of an expanded plasma volume. This case suggests that clinicians should pay special attention to achieving volume control in patients with BCS, particularly during laparoscopic surgery and minimizing the duration of pneumoperitoneum.

Autoimmune pancreatitis associated with pancreatic cyst: how can we manage it?

BACKGROUND: Autoimmune pancreatitis (AIP) with cyst formation (ACF) is often refractory to corticosteroid treatment (CST). AIM: To determine the characteristic features for the development of ACF. METHODS: We studied characteristics in AIP patients (n = 116) whether any factors might be related to ACF. Additionally, an individual database of 24 patients was compiled to investigate factors included CST effectiveness. RESULT: The results of univariate analysis for type 1 AIP patients revealed significant association of ACF with the elevation of pancreatic enzymes, peripancreas vascular involvement (PVI) and varix formation at disease onset (P < 0.05), while multivariate analysis revealed only the absence of varix formation (odds ratio = 0.033, P = 0.0015) as a significant independent predictor of the development of ACF. The comparison of the characteristic features in ACF grouped by the diameter of the cysts revealed that only the effectiveness of the CST was significantly recognized in ACF measuring less than 55 mm in diameter than that with patients in the group with smaller cysts (P < 0.05). CONCLUSION: The varix formation is an independent predictor of the development of ACF. A pooled analysis indicated that the disease process might be irreversible in AIP patients with large cystic lesions exceeding 55 mm in diameter and those patients tended to show a refractory course even if CST were conducted.

Visceral obesity as a risk factor for left-sided diverticulitis in Japan: a multicenter retrospective study.

BACKGROUND/AIMS: Left-sided diverticulitis is increasing in Japan, and many studies report that left-sided diverticulitis is more likely to be severe. Therefore, it is important to identify the features and risk factors for left-sided diverticulitis. We hypothesized that left-sided diverticulitis in Japan is related to obesity and conducted a study of the features and risk factors for this disorder in Japan. METHODS: Right-sided diverticulitis and left-sided diverticulitis patients (total of 215) were compared with respect to background, particularly obesity-related factors to identify risk factors for diverticulitis. RESULTS: There were 166 (77.2%) right-sided diverticulitis patients and 49 (22.8%) left-sided diverticulitis patients. The proportions of obese patients (body mass index ≥25 kg/m(2), p=0.0349), viscerally obese patients (visceral fat area ≥100 cm(2), p=0.0019), patients of mean age (p=0.0003), and elderly patients (age ≥65 years, p=0.0177) were significantly higher in the left-sided-diverticulitis group than in the right-sided-diverticulitis group. The proportion of viscerally obese patients was significantly higher in the left-sided-diverticulitis group than in the left-sided-diverticulosis group (p=0.0390). CONCLUSIONS: This study showed that obesity, particularly visceral obesity, was a risk factor for left-sided diverticulitis in Japan.

Metformin efficacy and safety for colorectal polyps: a double-blind randomized controlled trial.

BACKGROUND: Colorectal cancer is one of the major neoplasms and a leading cause of cancer death worldwide, and new preventive strategies are needed to lower the burden of this disease. Metformin, a biguanide, which is widely used for treating diabetes mellitus, has recently been suggestive to have a suppressive effect on tumorigenesis and cancer cell growth. In a previous study conducted in non-diabetic subjects, we showed that oral short-term low-dose metformin suppressed the development of colorectal aberrant crypt foci (ACF). ACF have been considered as a useful surrogate biomarker of CRC, although the biological significance of these lesions remains controversial. We devised a prospective randomized controlled trial to evaluate the chemopreventive effect of metformin against metachronous colorectal polyps and the safety of this drug in non-diabetic post-polypectomy patients. METHODS/DESIGN: This study is a multi-center, double-blind, placebo-controlled, randomized controlled trial to be conducted in non-diabetic patients with a recent history of undergoing colorectal polypectomy. All adult patients visiting the Yokohama City University hospital or affiliated hospitals for polypectomy shall be recruited for the study. Eligible patients will then be allocated randomly into either one of two groups: the metformin group and the placebo group. Patients in the metformin group shall receive oral metformin at 250 mg per day, and those in the placebo group shall receive an oral placebo tablet. At the end of 1 year of administration of metformin/placebo, colonoscopy will be performed to evaluate the polyp formation. DISCUSSION: This is the first study proposed to explore the effect of metformin against colorectal polyp formation. Metformin activates AMPK, which inhibits the mammalian target of rapamycin (mTOR) pathway. The mTOR pathway plays an important role in the cellular protein translational machinery and cell proliferation. Patients with type 2 diabetes taking under treatment with metformin have been reported to be at a lower risk of cancer development than those not taking under treatment with metformin. We showed in a previous study that metformin suppressed the formation of human colorectal ACF. We therefore decided to conduct a study to determine whether metformin might suppress the formation of human colorectal polyps. TRIAL REGISTRATION: This trial has been registered in the University hospital Medical Information Network (UMIN) Clinical Trials Registry as UMIN000006254.

Risk factors for mortality in patients with Mallory-Weiss syndrome.

BACKGROUND/AIMS: Although the majority of patients with Mallory-Weiss syndrome (MWS) have a benign course, in some patients MWS results in a fatal outcome. Therefore, this study was carried out to analyze the risk factors for mortality in patients with MWS. METHODOLOGY: The medical records of patients with MWS seen between March 1994 and July 2007 were reviewed retrospectively. The demographic characteristics, clinical and laboratory parameters, and endoscopic findings of the patients were analyzed and the risk factors for mortality were evaluated. RESULTS: A total of ninety-three patients (13 female and 80 male patients; median age, 53 years) were treated. The mortality rate was 9.7% (9/93). The patients with a fatal outcome were of advanced age and had a higher frequency of shock on arrival, lower hemoglobin level, more prolonged prothrombin time, higher AST and ALT levels, higher frequency of detection of exposed vessels on endoscopy, higher frequency of rebleeding, longer hospital stay, and required a larger volume of blood transfusion than those who did not have a fatal outcome. According to the results of a multivariate analysis, the significant risk factors for mortality in the MWS patients were advanced age (OR 1.222, 95% CI 1.015-1.028), very low hemoglobin level (OR 2.137, 95% CI 1.063-4.295), elevated AST level (OR 1.007, 95% CI 1.001-1.013), and presence of the clinical symptom of tarry stool (OR 45.45, 95% CI 1.080-1000). CONCLUSIONS: Intensive care with close monitoring is required for patients of advanced age with a low hemoglobin level, an elevated AST level, and the clinical symptom of tarry stool, since these are of prognostic importance in terms of the mortality in MWS patients.

Solitary Peutz-Jeghers type hamartomatous polyps in the duodenum are not always associated with a low risk of cancer: two case reports.

INTRODUCTION: A hamartomatous polyp without associated mucocutaneous pigmentation or a family history of Peutz-Jeghers Syndrome is diagnosed as a solitary Peutz-Jeghers type hamartomatous polyp. As compared with Peutz-Jeghers Syndrome, Peutz-Jeghers type hamartomatous polyps are diagnosed with a lower risk of cancer and are regarded as a different disorder. CASE PRESENTATION: In case one, we describe an 84-year-old Japanese man with a 14 mm duodenal polyp. Endoscopic mucosal resection was performed and histological examination showed findings suggestive of a hamartomatous polyp with a focus of well-differentiated adenocarcinoma. In case two, we describe a 76-year-old Japanese man who had been treated for prostate, rectal and lung cancer. Upper gastrointestinal endoscopy revealed a duodenal polyp measuring 15 mm in diameter. Endoscopic mucosal resection was performed, and histological examination showed findings suggestive of a hamartomatous polyp. Liver and thyroid cancers were found after the endoscopic treatment. CONCLUSION: Although duodenal solitary hamartomatous polyps are associated with a lower risk of cancer, four patients, including our cases, have been diagnosed with cancerous polyps. Patients with duodenal solitary hamartomatous polyps should be treated by endoscopic or surgical resection and need whole-body screening.

Incidence of and risk factors for upper gastrointestinal complications in patients taking low-dose aspirin in Japan.

BACKGROUND/AIMS: Low-dose aspirin is widely used for the prevention of cardiovascular and cerebrovascular diseases. However, administration of low-dose aspirin is associated with an increased risk of upper gastrointestinal complications, such as upper gastrointestinal erosions, ulcers and bleeding. The aim of this study was to clarify the prevalence and various clinical factors of upper gastrointestinal complications associated with low-dose aspirin treatment. METHODOLOGY: A total of 1213 patients taking low-dose aspirin were evaluated with upper endoscopic examinations. We studied retrospectively the incidence of and risk factors for upper gastrointestinal complications associated with low-dose aspirin use. RESULTS: Of the 1213 patients taking low-dose aspirin, 598 patients and 72 patients were found to have gastroduodenal erosions (57.3%) and peptic ulcers (5.9%), respectively. Of these 72 peptic ulcers, 27 were diagnosed as hemorrhagic ulcers. Previous ulcer history was identified as a risk factor for peptic ulcer and upper gastrointestinal bleeding during low-dose aspirin therapy. Upper gastrointestinal symptoms and no use of gastroprotective agents were also identified as risk factors for peptic ulcers. In this study, the use of a histamine-2 receptor antagonist was indicated as a protective factor for peptic ulcers. CONCLUSIONS: Low-dose aspirin therapy is associated with an increased risk of developing upper gastrointestinal complications. Administration of a histamine-2 receptor antagonist was effective for the prevention of low-dose aspirin induced peptic ulcers.

Factors predictive of relapse and spontaneous remission of autoimmune pancreatitis patients treated/not treated with corticosteroids.

BACKGROUND: Relapse and spontaneous remission (SR) are characteristic features of autoimmune pancreatitis (AIP). AIM AND METHODS: We conducted a study to determine if the predictive factors might be potentially related to the relapse in 70 consecutive AIP patients. Regarding SR, we studied the data of patients without corticosteroid treatment (CST). RESULTS: CST was administered to 60% (42/70) of the patients; however, relapse was noted in 45.2% (19/42) of these patients. In 95% (18/19) of the AIP patients developing relapse, the relapse occurred within 3 years. The relapse rate was 80% (12/15) in the AIP patients administered CST for less than 12 months and 25.9% (7/27) in those administered CST for over 12 months (p < 0.01). The results of univariate analysis revealed significant association of relapse with the presence of jaundice, IgG4 seropositivity, presence of diffuse pancreas swelling, duodenal papillitis (DP), history of initial CST, and history of supportive treatment (p < 0.05), whereas multivariate analysis revealed that IgG4 seropositivity (OR 10.506, p = 0.0422) and the presence of jaundice (OR 6.945, p = 0.0174) are significant independent factors predictive of relapse in AIP patients. SR was recognized in 65.0% (13/20) of AIP patients without CST. The results of univariate analysis revealed that SR was associated with IgG4 seropositivity (p < 0.05), and multivariate analysis identified IgG4 seropositivity (OR 0.032, p = 0.0092) as a significant independent factor predictive of SR in these cases. CONCLUSION: AIP patients with IgG4 seropositivity and jaundice are at a higher risk of relapse and they could therefore be candidates for over 3 years of maintenance CST. AIP patients with IgG4 seronegativity have a high likelihood of SR.

Management of acute lower intestinal bleeding: what bowel preparation should be required for urgent colonoscopy?

BACKGROUND/AIMS: The management of acute intestinal bleeding is not standardized. The aim of this study was to determine the most suitable method of bowel preparation for urgent colonoscopy. METHODOLOGY: One hundred and forty patients admitted with acute lower intestinal bleeding (ALIB) to our Hospital (April 1998 to March 2004) were studied. The preparation for colonoscopy consisted, usually, of oral administration of polyethylene glycol (PEG)-salt solution. For elderly patients or for those suspected of bleeding from a sigmoid colon lesion, colonoscopy was performed following glycerin enemas or water enemas. For patients with a suspected rectal lesion or soon after undergoing a polypectomy, colonoscopy was performed without any of the above procedures. RESULTS: Ischemic colitis was the most common cause of bleeding. The overall cecal completion ratio was 41%, compared with 74% in the PEG group. The percentage of those in whom colonoscopy was impossible (poor preparation) was 16% overall, compared with 5% in the PEG group. Endoscopic hematemesis were performed successfully for 26 patients who were mainly postpolypectomy cases or had rectal ulcers. CONCLUSIONS: In urgent colonoscopy, the preparation with PEG-salt solution may improve the patient's outcome. In postpolypectomy patients and those with rectal ulcers preparation was not always needed.

Effects of body positions on gastric emptying with enteral nutrition: a crossover study using a continuous real time 13C breath test (BreathID system).

BACKGROUND/AIMS: The aim of this study was to determine whether there was a correlation between body positions and gastric emptying, using a novel non-invasive technique for measuring gastric emptying with a continuous real time 13C breath test (BreathID system). METHODOLOGY: Ten healthy male volunteers participated in this randomized, two-way crossover study. On both occasions, the 13C breath test was performed for 4 hours using the BreathID system with a liquid meal (200 kcal per 200 mL) containing 100 mg 13C-acetic acid. Subjects were randomly assigned to sit comfortable (the sitting position) or to lie supine (the lying position). RESULTS: In the lying position, T 1/2 and T lag were significantly delayed. The gastric emptying coefficient was also decreased in lying position. CONCLUSIONS: This study showed that gastric emptying following a liquid meal was significantly delayed in the lying position compared to the sitting position, suggesting the potential use of these findings in the clinical setting for patients receiving enteral nutrition via the stomach.

Characterization of K-ras gene mutations in association with mucinous hypersecretion in intraductal papillary-mucinous neoplasms.

BACKGROUND/PURPOSE: Intraductal papillary-mucinous neoplasms (IPMNs) of the pancreas have a favorable prognosis. However, invasive ductal carcinomas of the pancreas show a rapid progression. The aim of this study was to investigate gene mutations in pure pancreatic juice from IPMN patients and to define these genetic mutations in relation to the histopathological and clinical features of IPMNs. METHODS: Twenty-two patients with IPMN, 21 patients with ductal carcinoma, and 20 patients with normal pancreas or chronic pancreatitis were recruited for this study. We measured the main pancreatic duct's largest diameter and the maximum size of a dilated branch was assessed by ultrasonography or endoscopic ultrasonography. Pure pancreatic juice was collected and was investigated for K-ras, p16, and p53 mutations. RESULTS: Mutant K-ras gene was detected in 13 of the 22 patients (59.1%) with IPMNs. Different kinds of mutations were detected in the same patient in 4 cases. In the 13 patients with mutant K-ras gene, the diameter of the most dilated part of the main pancreatic duct was 2-8 mm (average, 4.5 mm) and in 7 patients with wild-type K-ras gene, the diameter was 2-5 mm (average, 2.7 mm). There was a significant difference in the diameter of the main pancreatic duct between patients with and without the mutant K-ras gene (P = 0.0323). CONCLUSIONS: The incidence of K-ras mutation may be associated with the hypersecretion of mucin.

Peroxisome proliferator-activated receptor gamma (PPARgamma) suppresses colonic epithelial cell turnover and colon carcinogenesis through inhibition of the beta-catenin/T cell factor (TCF) pathway.

Peroxisome proliferator-activated receptor gamma (PPARgamma), a nuclear receptor superfamily member, plays a major role in lipid metabolism and insulin sensitivity. We investigated the role of PPARgamma in colonic epithelial cell turnover and carcinogenesis in colon because PPARgamma is strongly expressed in colonic epithelium. Administration of PPARgamma agonists suppressed epithelial cell turnover in mice. Expression level of beta-catenin protein, a key molecule in carcinogenesis, was increased in mouse colon treated with PPARgamma ligands. A direct interaction between beta-catenin and PPARgamma in cultured cell lines and colonic epithelium in mice was observed. Ligand-activated PPARgamma ligand directly interacts with beta-catenin, retaining it in the cytosol and reducing beta-catenin/T cell factor (TCF) transcriptional activity that is functionally important on aberrant crypt foci (ACF) formation. PPARgamma hetero-deficiency promoted the induction of ACF, but had no effect on the incidence of colonic polyps. These results indicate that PPARgamma regulates colonic epithelial cell turnover via direct interactions with beta-catenin, resulting in inhibition of beta-catenin-mediated transcriptional pathways that are involved in promoting cell proliferation. Our findings suggest that PPARgamma plays a role as a physiological regulator of colonic epithelial cell turnover and consequently predisposition to the development of colon cancer in early stage.

Blockade of leukotriene B4 signaling pathway induces apoptosis and suppresses cell proliferation in colon cancer.

We investigated whether leukotriene B(4) (LTB(4)) and its signaling pathway play an important role in the progression of human colon cancer via a direct stimulation of cancer cell proliferation. Remarkable expression of LTB(4) receptor 1 (BLT1) in human colon cancer tissues was detected by immunohistochemistry, and Western blot analysis revealed the BLT1 expression in cultured human colon cancer cell lines, Caco2 and HT29. The 5-lipoxygenase inhibitor AA-861 and LTB(4)-receptor antagonist U75302 showed negative effects on survival and proliferation of both Caco2 and HT-29 cells. The inhibition of cell proliferation is due to the apoptosis because nuclear condensation and increased annexin V expression were observed in the cells treated with AA-861 and U75302. Knockdown of BLT1 by small interfering RNA caused the suppression of BLT1 protein, resulting in the inhibition of cancer cell proliferation. Blockade of BLT1 by the receptor antagonist significantly suppresses the LTB(4)-stimulated extracellular signal-regulated kinase (ERK) activation in colon cancer cells. These results indicate that the blockade of the LTB(4)-signaling pathway induces apoptosis via the inhibition of ERK activation in colon cancer cells. The LTB(4)-signaling pathway might be a new therapeutic target for colon cancer.

Characterization of portal vein thrombus with the use of contrast-enhanced sonography.

OBJECTIVES: To select an appropriate treatment regimen, it is essential to accurately characterize the nature of a thrombus. This study prospectively assessed the ability of contrast-enhanced sonography to differentiate between benign and malignant portal vein thrombosis in a population of high-risk patients. METHODS: Fifty-five patients (43 men and 12 women; mean age, 66 years; range, 55-83 years) with thrombi of the portal venous system were examined by power Doppler sonography and contrast-enhanced sonography with the intravenous contrast agent SH U 508A (Levovist; Schering AG, Berlin, Germany). Of the thrombi, 40 were characterized as malignant and 15 as benign. Pulsatile flow in the thrombus on power Doppler sonography and positive enhancement of the thrombus on contrast-enhanced sonography were judged as indications of a malignant thrombus. The sensitivity and specificity of both methods in differentiating the nature of the thrombus were evaluated. RESULTS: The detection of pulsatile flow in a portal vein thrombus as the criterion for diagnosing malignant portal vein thrombus yielded overall sensitivity of 82.5% and specificity of 100%, whereas positive enhancement of the portal vein thrombus itself as a criterion for diagnosing malignancy yielded overall sensitivity and specificity of 100% for each. CONCLUSIONS: Contrast-enhanced sonography can be helpful in discriminating between benign and malignant portal vein thrombi.

[Clinical features of long time survivors with unresectable pancreatic cancer treated by gemcitabine alone].

The objective of this study was to clarify the clinical features of long-time survivors with unresectable pancreatic cancer treated by gemcitabine (GEM) alone and to predict survival time after the first course of treatment. Eighteen consecutive patients (median age 65.3 years, range 49-77 years; 12 males, 6 females) with unresectable pancreatic cancer and a baseline Karnofsky's performance state = or >60 were treated with GEM in a dose of 1,000 mg/m(2) weekly x 3 followed by 1 week of rest until progression. The overall response rate was 0% (CR 0, PR 0, SD 11 cases, and PD 5 cases), and the median survival time (MST) was 268 days. We observed a statistically significant difference in the patients with or without liver metastasis at the start of treatment (131.6 vs 324.9 days; p=0.0045). We also evaluated the usefulness of serial CA 19-9 measurements as a biochemical response marker and an outcome prognostic parameter in patients with unresectable pancreatic cancer receiving GEM alone. We classified two subgroups into responders (patients with a decrease of = or >10% of the baseline CA 19-9 level after 4 weeks of chemotherapy) and non-responder (patients with a increase of the baseline CA 19-9 level or with a decrease of <10% of the baseline CA 19-9 level after 4 weeks of chemotherapy). Responder had a significantly better median survival than non-responders (416.6 vs 138.3 days; p=0.009). In conclusion, CA 19-9 serum concentration serves as an early indicator of response to chemotherapy with GEM alone in unresectable pancreatic cancer.