Masanao Kurata

Differentiation of autoimmune pancreatitis from pancreatic cancer by diffusion-weighted MRI.

OBJECTIVES:We sought to clarify the clinical utility of diffusion-weighted magnetic resonance imaging (DWI) for differentiating autoimmune pancreatitis (AIP) from pancreatic cancer.METHODS:Thirteen AIP patients underwent DWI before therapy, and six of them underwent DWI after steroid therapy. The extent and shape of high-intensity areas were compared with those of 40 pancreatic cancer patients. Apparent diffusion coefficient (ADC) values were calculated in the AIP area before and after steroid therapy in pancreatic cancer patients and in a normal pancreatic body.RESULTS:On DWI, AIP and pancreatic cancer were detected as high-signal intensity areas. The high-intensity areas were diffuse (n=4), solitary (n=6), and multiple (n=3) in AIP patients, but all pancreatic cancer patients showed solitary areas (P<0.001). A nodular shape was significantly more frequent in pancreatic cancer, and a longitudinal shape was more frequently found in AIP (P=0.005). ADC values were significantly lower in AIP (1.012±0.112 × 10−3 mm2/s) than in pancreatic cancer (1.249±0.113 × 10−3 mm2/s) and normal pancreas (1.491±0.162 × 10−3 mm2/s) (P<0.001). Receiver operating characteristic analysis yielded an optimal ADC cutoff value of 1.075 × 10−3 mm2/s to distinguish AIP from pancreatic cancer. After steroid therapy, high-intensity areas on DWI disappeared or were markedly decreased, and the ADC values of the reduced pancreatic lesions increased almost to the values of normal pancreas.CONCLUSIONS:DWI is useful for detecting AIP and for evaluating the effect of steroid therapy. ADC values were significantly lower in AIP than in pancreatic cancer. An ADC cutoff value may be useful for distinguishing AIP from pancreatic cancer.

Rapid and aggressive recurrence accompanied by portal tumor thrombus after radiofrequency ablation for hepatocellular carcinoma.

Although radiofrequency ablation (RFA) has been reported to be a safe and effective procedure for the treatment of hepatocellular carcinoma (HCC), patterns of recurrence and complications following RFA treatment have not been fully identified. Recently, we have experienced two cases of HCC patients who developed rapid and aggressive recurrence accompanied by portal tumor thrombus after RFA therapy. The first was a 68-year-old woman with hepatitis C virus (HCV)-positive liver cirrhosis, who received percutaneous RFA therapy for a 27-mm-diameter HCC in segment VII. The other was a 64-year-old man with hepatitis B surface antigen (HBsAg)-positive liver cirrhosis and multiple bilobar HCCs, who underwent left hemihepatectomy and intraoperative RFA for the two tumors in the remnant liver. In both patients, though immediate imaging studies suggested complete necrosis of the tumors, recurrences with massive portal tumor thrombus occurred in 4 and 6 months, respectively. At present, it is unclear whether such a recurrence pattern is directly related to the RFA procedure. However, it is implied that RFA therapy may entail a risk of promoting portal venous invasion of HCC tumors.

Serum IgG4 concentrations and IgG4-related sclerosing disease

BACKGROUND Based on histological and immunohistochemical examinations of various organs of patients with autoimmune pancreatitis (AIP), a new clinicopathological entity, IgG4-related systemic disease, was proposed. This study aimed to clarify clinical utility of serum IgG4 levels in differentiating AIP from other pancreatobiliary diseases, clinical utility of serum IgG4 levels in differentiating Mikuliczs disease from other salivary gland disorders, as well as in identifying other IgG4-related diseases. METHODS Serum IgG4 levels were measured in 468 patients. RESULTS The median serum IgG4 level was significantly greater in AIP (301.5mg/dl) than in other pancreatobiliary diseases (p<0.01). Using the cutoff value of 119 mg/dl that was determined on the basis of this studys ROC curve data, the sensitivity and specificity to distinguish AIP from pancreatic cancer were 82.1% and 94.8%, respectively. The median serum IgG4 level was significantly greater in Mikuliczs disease (357.0mg/dl) than in other salivary gland diseases (p<0.01). Of 75 patients with elevated serum IgG4 levels, 15 had diseases other than pancreatobiliary and salivary gland diseases. CONCLUSIONS Serum IgG4 levels were useful for diagnosing AIP and Mikuliczs disease. Some diseases with serum IgG4 level elevations may be lesions of IgG4-related systemic disease without manifestations of AIP and Mikuliczs disease.

Predictors of malignancy and natural history of main-duct intraductal papillary mucinous neoplasms of the pancreas.

Objectives: Because the prevalence of carcinoma is high in main-duct intraductal papillary mucinous neoplasms (IPMNs) of the pancreas, surgical resection is recommended for all main-duct type IPMNs. This study aimed to investigate the clinical predictors of malignancy and natural history of main-duct IPMNs. Methods: Preoperative clinical characteristics reliably correlated with malignancy in 26 surgically resected patients with main-duct IPMN, and long-term outcome in 20 conservatively followed patients with main-duct IPMN was examined. Results: Age at diagnosis was significantly older in conservatively followed IPMN patients than in surgically resected IPMN patients. Main pancreatic duct (MPD) dilatation 10 mm or greater and mural nodules were significantly more frequent in malignant IPMNs. Obvious progression of dilatation of the MPD was detected in all 4 conservatively followed patients who developed invasive pancreatic carcinoma. The histology of IPMN at autopsy of 4 conservatively followed patients who died of other causes 21 to 120 months later was adenoma. Seven conservatively followed without malignant findings did not show obvious progression of MPD dilatation. Conclusions: Although surgical resection is indicated for many main-duct IPMNs, conservative follow-up may be an option for elderly asymptomatic patients with main-duct IPMNs with the MPD less than 10 mm, no obvious mural nodule, and negative cytology.

The critical view of safety in laparoscopic cholecystectomy is optimized by exposing the inner layer of the subserosal layer

During laparoscopic cholecystectomy (LC), misidentification of the cystic duct, which causes major bile duct injuries, can result from wrong or incomplete dissection of Calots triangle. Therefore, the critical view of safety has been accepted as a safe method for gaining a sufficient view of Calots triangle before transecting the cystic duct. However, even in cases without aberrant anatomy of the bile duct, bile duct injury can occur by a wrong approach to a critical view of safety. Additionally, in cases of badly inflamed gallbladders, it is often hard to achieve a critical view of safety, because Calots triangle is often solid and cannot be expanded. In our standardized procedure, which is based on exposing the inner layer of the subserosal layer (the ss-i layer), the critical view of safety can be safely achieved. We have safely performed LC, using our standardized procedure, for many cases with cholecystitis with highly inflamed gallbladders. In this article, focusing especially on prevention of bile duct injuries, we present our standardized procedure to achieve the critical view of safety along with histological findings.

Biliopancreatic reflux-pathophysiology and clinical implications.

The common bile duct and the main pancreatic duct open into the duodenum, where they frequently form a common channel. The sphincter of Oddi is located at the distal end of the pancreatic and bile ducts; it regulates the outflow of bile and pancreatic juice. In patients with a pancreaticobiliary maljunction, the action of the sphincter does not functionally affect the junction. Therefore, in these patients, two-way regurgitation (pancreatobiliary and biliopancreatic reflux) occurs. This results in various pathological conditions of the biliary tract and the pancreas. Biliopancreatic reflux could be confirmed by: operative or postoperative T-tube cholangiography; CT combined with drip infusion cholangiography; histological detection of gallbladder cancer cells in the main pancreatic duct; and reflux of bile on the cut surface of the pancreas. Biliopancreatic reflux occurs frequently in patients with a long common channel. Although the true prevalence, degree, and pathophysiology of biliopancreatic reflux remain unclear, biliopancreatic reflux is related to the occurrence of acute pancreatitis. Obstruction of a long common channel easily causes bile flow into the pancreas. Even if no obstruction is present, biliopancreatic reflux can still result in acute pancreatitis in some cases.

Proposed preoperative risk factors for early recurrence in patients with resectable pancreatic ductal adenocarcinoma after surgical resection: A multi-center retrospective study

BACKGROUND/OBJECTIVE Although surgical resection remains the only chance for cure in patients with pancreatic ductal adenocarcinoma (PDAC), postoperative early recurrence (ER) is frequently encountered. The purpose of this study is to determine the preoperative predictive factors for ER after upfront surgical resection. METHODS Between 2001 and 2012, 968 patients who underwent upfront surgery with R0 or R1 resection for PDAC at seven high-volume centers in Japan were retrospectively reviewed. ER was defined as relapse within 6 months after surgery. Study analysis stratified by resectable (R) and borderline resectable (BR) PDACs was conducted according to the National Comprehensive Cancer Network guidelines. RESULTS ER occurred in 239 patients (25%) with a median survival time (MST) of 8.8 months. Modified Glasgow prognostic score = 2 (odds ratio (OR) 2.06, 95% confidence interval (CI) 1.05-3.95; P = 0.044), preoperative CA19-9 ≥300 U/ml (OR 1.94, 1.29-2.90; P = 0.003), and tumor size ≥30 mm (OR 1.72, 1.16-2.56; P = 0.006), were identified as preoperative independent predictive risk factors for ER in patients with R-PDAC. In the R-PDAC patients, MST was 35.5, 26.3, and 15.9 months in patients with 0, 1 and ≥2 risk factors, respectively. There were significant differences in overall survival between the three groups (P < 0.001). No preoperative risk factors were identified in BR-PDAC patients with a high rate of ER (39%). CONCLUSIONS There is a high-risk subset for ER even in patients with R-PDAC and a simple risk scoring system is useful for prediction of ER.

Pancreaticoduodenectomy in portal annular pancreas: report of a case

Portal annular pancreas (PAP) is a rare anatomical anomaly in which the pancreatic parenchyma surrounds the superior mesenteric vein and portal vein (PV) annularly. This anomaly requires careful consideration in pancreatic resection. A case is presented and the technical issues are discussed. A 61-year-old female was referred to the hospital for suspected papilla Vater adenocarcinoma. Preoperative computed tomography showed that the PV was annularly surrounded by pancreatic parenchyma. Surgery revealed the uncinate process extended extensively behind the PV and fused with the pancreatic body. The pancreas was first divided above the PV, and it was divided again in the body after liberating the PV from pancreatic annulation. The postoperative course was uneventful without pancreatic fistula. It is safer to divide the pancreatic body on the left of the fusion between the uncinate process and the pancreatic body to reduce the risk of pancreatic fistula in pancreaticoduodenectomy for PAP.

Intraductal papillary mucinous neoplasm of the pancreas and IgG4-related disease: A coincidental association

BACKGROUND/AIMS Coexistence of autoimmune pancreatitis (AIP) and pancreatic cancer, elevation of serum IgG4 levels in pancreatic cancer patients, and infiltration of IgG4-positive plasma cells in peritumorous pancreatitis have been described in a few reports. This study examined the relationship between intraductal papillary mucinous neoplasm (IPMN) of the pancreas and peritumorous IgG4-positive lymphoplasmacytic infiltrates. METHODS Serum IgG4 levels were measured in 54 patients with IPMN (median 70 years, 26 males and 28 females; 13 main duct type and 41 branch duct type). Histological findings focusing on dense lymphoplasmacytic infiltration, storiform fibrosis, and obliterative phlebitis were reviewed, and immunostaining with IgG4 and IgG was performed in 23 surgically resected IPMN cases (18 main duct type and 5 branch duct type). The presence of IgG4-positive plasma cells >10/hpf and an IgG4-positive/IgG-positive plasma cell ratio >40% were considered significant. RESULTS Serum IgG4 levels were elevated in 2 (4%) IPMN patients. Significant infiltration of IgG4-positive plasma cells was detected in 4 IPMN cases (17%). The IgG4-positive/IgG-positive plasma cell ratio was >40% in all 4 cases. In one case with a markedly elevated serum IgG4 level (624 mg/dL), typical lymphoplasmacytic sclerosing pancreatitis (AIP type 1) lesions surrounded the whole IPMN. In the 3 other cases, infiltration of IgG4-positive plasma cells with fibrosis was focally detected mainly in the periductal area around the IPMN. CONCLUSIONS In a few patients with IPMNs, IgG4-positive plasma cell infiltration can occur in the peritumorous area. The association of an IPMN with AIP type 1-like changes seems to be exceptional and coincidental.

Useful and convenient procedure for intermittent vascular occlusion in laparoscopic hepatectomy

While the amount of blood loss during laparoscopic hepatectomy tends to be smaller than that during open hepatectomy, intermittent vascular occlusion to control hepatic inflow can diminish blood loss during laparoscopic hepatectomy. Described herein is a useful and convenient method for intermittent vascular occlusion, which was standardized for laparoscopic hepatectomy.