Adrenocortical carcinoma mimicking hepatocellular carcinoma: A case report

INTRODUCTION AND IMPORTANCE

Adrenocortical carcinoma (ACC) is a relatively rare tumor arising in the adrenal cortex. Its imaging and histopathologic findings are not well known to be similar to those of hepatocellular carcinoma (HCC). We report here a case of ACC with hepatic resection in the preoperative diagnosis of HCC.

CASE PRESENTATION

A 46-year-old woman was noted to have a tumor 45 mm in size in the segment 7 of the liver on CT during a medical checkup. The tumor had consistent imaging findings as HCC on Ultrasound, CT, and MRI examinations, and the result of the liver tumor biopsy was a diagnosis of intermediate differentiated HCC. We considered the tumor to be HCC and performed a posterior segmentectomy with combined resection of the right adrenal gland, which had adhesions suspected to direct invasion. The pathology of the resected specimen confirmed the diagnosis of ACC with direct invasion into the liver.

CLINICAL DISCUSSION

ACC may show a contrast pattern similar to that of HCC on imaging, and histopathology may show atypical cells with eosinophilic sporulation, similar to that of HCC. Our case serves to alert physicians that ACC should be considered a differential diagnosis in patients with suspected HCC in the posterior segment.

CONCLUSION

Tumors suspected of HCC in the dorsal posterior segment of the liver should be considered as possible ACC.

Prognostic Impact of Relative Dose Intensity of Adjuvant Chemotherapy With S-1 on Pancreatic Ductal Adenocarcinoma

BACKGROUND/AIM

Although adjuvant chemotherapy (AC) with S-1 is currently the standard treatment for pancreatic ductal adenocarcinoma (PDAC) in Japan, the associations between its relative dose intensity (RDI) and survival outcomes remain unclear.

PATIENTS AND METHODS

We reviewed 310 patients with PDAC who had undergone pancreatectomy from January 2014 to June 2020 at three institutions. Of these, patients who had received adjuvant S-1 monotherapy were analyzed. Patients who had died or developed recurrences within 6 months, or received neoadjuvant chemotherapy, were excluded from the analyses. Possible predictors of overall survival (OS), including RDI, were analyzed using Cox regression. The cutoff value for RDI was determined by receiver operating characteristic analysis.

RESULTS

Ninety-four patients with a median age of 69 years (range=39-84 years) were analyzed. In the high-RDI group (RDI≥72.3%, n=74), the OS rates were 98.5% and 80.8% at 1 and 3 years, respectively, whereas in the low-RDI group (RDI <72.3%, n=20) they were 88.9% and 51.6%, respectively (p=0.001). By multivariate analysis, lymph node metastasis [hazard ratio (HR)=3.06; p=0.020], low RDI (HR=2.95; p=0.020), and time interval from surgery to initiation of AC > 51 days (HR=2.50; p=0.046) were independently associated with inferior OS. The combination of the latter two factors clearly stratified both OS and recurrence-free survival (p<0.001 and p=0.017, respectively).

CONCLUSION

Early initiation and maintenance of RDI of S-1 monotherapy after pancreatectomy may improve the OS of PDAC patients.

Hepatocellular carcinoma with situs inversus totalis treated by caudate lobectomy: A case report

Introduction

Situs inversus totalis (SIT) is a congenital anatomical variant in which organs and vasculature are positioned in a mirror-image relationship to the normal condition. Therefore, the surgical procedures need to be carefully planned with these factors in mind.

Case presentation

A 57-year-old man with SIT was diagnosed with a hepatocellular carcinoma (HCC) and was planned for caudate lobectomy. As preoperative preparation, 3D reconstructed images were created based on the contrast-enhanced CT images, and careful simulations were performed on the vascular anomalies and location of the tumor. There was a replaced left hepatic artery forming a common trunk with a left gastric artery. In addition, using media player software, a previous caudate lobectomy video was played in right and left inverted mode to simulate the abdominal surgical field image in SIT. The operative time was 285 min, and the blood loss was 440 ml. The preoperative careful simulation allowed us to proceed with the surgery without significant discomfort.

Conclusion

Even in the case of hepatocellular carcinoma with SIT, hepatectomy for hepatocellular carcinoma can be safely performed by careful preoperative simulations.

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This is a case of caudate lobectomy for hepatocellular carcinoma with situs inversus totalis.

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We repeatedly watched a previous caudate lobectomy video played in right and left inverted mode prior to the surgery.

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With careful preoperative simulations, liver resection can be safely performed in patients with SIT.

Application of laparoscopic distal pancreatectomy for normal anatomy after hiatal hernia repair: A case report

We describe a case of pancreatic tumor associated with a giant type IV hiatal hernia that had prolapsed into the posterior mediastinum. Hiatal hernia repair should be performed first because it enables laparoscopic distal pancreatectomy to be performed in the normal anatomical position.

A case of retroperitoneal abscess caused by infection of urachal remnant

Infection of urachal remnant may cause recurrent abscesses. In the current case report, we describe a urachal remnant infection leading to a retroperitoneal abscess, which is an extremely rare condition. In such cases, the recommended treatment is urachal remnant resection.

The urachal remnant infection leading to a retroperitoneal abscess is an extremely rare condition. Urachal remnant resection is the recommended treatment for radical cure.

Carcinosarcoma of the Thoracic Esophagus That Presented as Focal Ulcerative Lesion

Esophageal carcinosarcoma is a rare malignant tumor composed of both carcinomatous and sarcomatous elements. We report a case of esophageal carcinosarcoma in a 56-year-old woman with dysphagia. Esophageal ulcerative tumors were detected by endoscopy and resected by thoracoscopic esophagectomy. Carcinosarcoma was confirmed by the presence of both carcinomatous and sarcomatous tumor components. On immunohistochemistry, the sarcomatous area was positive for keratin staining, while the sarcomatous area was positive for vimentin staining. The tumor reportedly had a better prognosis than SCC of the esophagus, especially in terms of survival rate. The patient's disease was classified as ypT3N0M0, ypStage II. No definitive diagnosis was made preoperatively. We report this case along with a review of the literature.

Integrated GWAS and mRNA Microarray Analysis Identified IFNG and CD40L as the Central Upstream Regulators in Primary Biliary Cholangitis

Genome‐wide association studies (GWASs) in European and East Asian populations have identified more than 40 disease‐susceptibility genes in primary biliary cholangitis (PBC). The aim of this study is to computationally identify disease pathways, upstream regulators, and therapeutic targets in PBC through integrated GWAS and messenger RNA (mRNA) microarray analysis. Disease pathways and upstream regulators were analyzed with ingenuity pathway analysis in data set 1 for GWASs (1,920 patients with PBC and 1,770 controls), which included 261 annotated genes derived from 6,760 single‐nucleotide polymorphisms (P < 0.00001), and data set 2 for mRNA microarray analysis of liver biopsy specimens (36 patients with PBC and 5 normal controls), which included 1,574 genes with fold change >2 versus controls (P < 0.05). Hierarchical cluster analysis and categorization of cell type–specific genes were performed for data set 2. There were 27 genes, 10 pathways, and 149 upstream regulators that overlapped between data sets 1 and 2. All 10 pathways were immune‐related. The most significant common upstream regulators associated with PBC disease susceptibility identified were interferon‐gamma (IFNG) and CD40 ligand (CD40L). Hierarchical cluster analysis of data set 2 revealed two distinct groups of patients with PBC by disease activity. The most significant upstream regulators associated with disease activity were IFNG and CD40L. Several molecules expressed in B cells, T cells, Kupffer cells, and natural killer–like cells were identified as potential therapeutic targets in PBC with reference to a recently reported list of cell type–specific gene expression in the liver. Conclusion: Our integrated analysis using GWAS and mRNA microarray data sets predicted that IFNG and CD40L are the central upstream regulators in both disease susceptibility and activity of PBC and identified potential downstream therapeutic targets.

Predictors of portal and splenic vein thrombosis after laparoscopic splenectomy: a retrospective analysis of a single-center experience

PURPOSE

Laparoscopic splenectomy (LS) has become the standard operative approach for splenectomy. Portal or splenic vein thrombosis (PSVT) is a serious and common complication after LS, and lethal complications of PSVT can occur when the portal vein is completely occluded by portal vein thrombosis (PVT). We aimed to clarify the predictors of PSVT after LS and to determine which of them were also predictors of PVT.

METHODS

A total of 56 consecutive patients who underwent elective LS were enrolled in this study. The patients were divided into two groups based on the presence or absence of PSVT after LS. In addition, patients with PSVT were divided into two groups: a PVT group and a non-PVT group. The preoperative and intraoperative clinical data were compared among the groups.

RESULTS

Thirty (53.6%) patients developed PSVT. The splenic vein diameter was the most useful predictor for the development of PSVT, and 10 mm was an accurate splenic vein diameter cut-off value for use as a predictive factor for PSVT. In addition, the splenic vein diameter was the most useful predictor of the development of PVT from splenic vein thrombosis (SVT), and 14 mm was found to be an accurate cut-off value.

CONCLUSION

PSVT is a common postoperative complication that is identified on enhanced computed tomography. The splenic vein diameter is not only a predictor of PSVT but also of the development of PVT from SVT.

The long-term survival in primary retroperitoneal mucinous cystadenocarcinoma: a case report

Background

Primary retroperitoneal mucinous cystadenocarcinoma (PRMC) is extremely rare, and its biological behavior, pathogenesis, optimum treatments, and prognosis remain to be elucidated. We herein report a case of PRMC with an 80-month follow-up.

Case presentation

A 29-year-old woman was diagnosed with unknown retroperitoneal tumor with benign right ovarian cyst and uterine fibroids, and she underwent laparotomy. The tumor was completely resected with a subsequent histopathological diagnosis of primary retroperitoneal mucinous cystadenocarcinoma (PRMC). Eighty months after surgery, she remains recurrence-free.

Conclusion

PRMC is an extremely rare tumor. Only around 60 cases have so far been published in the literature. The preoperative diagnosis of PRMC is difficult, and a definitive diagnosis can usually only be made based on the findings of histopathological examinations after surgery. Presently, only radical resection is useful for both diagnostic and therapeutic purposes. The optimal long-term management after surgery is still not well established. Further studies on PRMC are therefore needed to elucidate the etiology and establish effective treatments.

A Modified Method for Purifying Gallbladder Epithelial Cells Using Fluorescence-activated Cell Sorting

BACKGROUND

We have previously reported a procedure for isolating and culturing biliary epithelial cells (BECs). The aim of this study was to reconsider the method for obtaining pure BECs using the mouse gallbladder.

MATERIALS AND METHODS

Cells that were obtained from the gallbladder alone were sorted by fluorescence-activated cell sorting (FACS) for purifying based on the expression of the epithelial cell adhesion molecule (EpCAM). The viability rate was measured based on the negative expression of 7-aminoactinomycin D (7-AAD).

RESULTS

More than 75% of cells from the gallbladder were determined to be pure BECs. An analysis of the EpCAM revealed that 73.3% of the cells were 7-AAD-negative. Finally, the 0.82×10⁶ pure BECs that survived were obtained and seeded on a collagen gel plate. However, these pure BECs showed almost no proliferation.

CONCLUSION

Pure BECs could be accumulated using FACS. However, the number of BECs was insufficient for the culturing process.

Analysis of early relaparotomy following living donor liver transplantation

We retrospectively analyzed the causes, risk factors, and impact of early relaparotomy after adult-to-adult living donor liver transplantation (LDLT) on the posttransplant outcome. Adult recipients who underwent initial LDLT at our institution between August 1997 and August 2015 (n = 196) were included. Any patients who required early retransplantation were excluded. Early relaparotomy was defined as surgical treatment within 30 days after LDLT. Relaparotomy was performed 66 times in 52 recipients (a maximum of 4 times in 1 patient). The reasons for relaparotomy comprised postoperative bleeding (39.4%), vascular complications (27.3%), suspicion of abdominal sepsis or bile leakage (25.8%), and others (7.6%). A multivariate analysis revealed that previous upper abdominal surgery and prolonged operative time were independent risk factors for early relaparotomy. The overall survival rate in the relaparotomy group was worse than that in the nonrelaparotomy group (6 months, 67.3% versus 90.1%, P < 0.001; 1 year, 67.3% versus 88.6%, P < 0.001; and 5 years, 62.6% versus 70.6%, P = 0.06). The outcome of patients who underwent 2 or more relaparotomies was worse compared with patients who underwent only 1 relaparotomy. In a subgroup analysis according to the cause of initial relaparotomy, the survival rate of the postoperative bleeding group was comparable with the nonrelaparotomy group (P = 0.96). On the other hand, the survival rate of the vascular complication group was significantly worse than that of the nonrelaparotomy group (P = 0.001). Previous upper abdominal surgery is a risk factor for early relaparotomy after LDLT. A favorable longterm outcome is expected in patients who undergo early relaparotomy due to postoperative bleeding. Liver Transplantation 22 1519-1525 2016 AASLD.

Relationship between immune function recovery and infectious complications in patients following living donor liver transplantation

AIM

The ImmuKnow (IK) assay enables the evaluation of peripheral blood CD4(+) adenosine triphosphate activity to facilitate an objective assessment of the cellular immune function in immunosuppressed patients. However, it is unclear whether the IK assay is utilized during the acute postoperative periods following living donor liver transplantation (LDLT).

METHODS

The IK values of 43 LDLT recipients were measured during the month following LDLT to evaluate the relationship between the measured IK values and infectious events.

RESULTS

The IK values after LDLT were significantly increased compared with the IK values before LDLT ( P < 0.01). During the month following transplantation, the rate of bacterial infection in the recipients with IK values of more than 225 ng/mL was significantly lower than that in the recipients with IK values of 225 ng/mL or less ( 42.1% vs 91.7%, respectively; P < 0.01). The rate of severe infections among the recipients who maintained IK values of more than 150 ng/mL was significantly lower than that among the recipients with IK values of 150 ng/mL or less during the month following transplantation ( 3.7% vs 56.3%, respectively; P < 0.01).

CONCLUSION

The immune system of LDLT recipients dramatically improved following transplantation. The IK values of LDLT recipients were associated with the incidence of infectious events during the perioperative period after LDLT. Monitoring IK values was useful during both the acute and long-term postoperative periods.

Triple-drug therapy to prevent pancreatic fistula after pancreatectomy in a rat model

BACKGROUND

Pancreatic fistula (PF) is one of post-operative complications in pancreatic surgery, but there is no consensus about the optimal treatment for PF. Our group has established a rat model of PF, and we conducted the present investigation to determine the efficacy of the triple-drug therapy (somatostatin analogue, gabexate mesilate, and imipenem/cilastatin) against PF using our rat model.

METHODS

In the PF rat model, the triple-drug therapy was administered to the treated (T) group (n = 4), and we compared the results with those of a control (C) group (n = 4). The rats were sacrificed on postoperative day 3 (POD 3) and the levels of amylase and lipase in serum and ascites were measured. The intra-abdominal adhesion was scored. Each pancreas was evaluated pathologically, and inflammation was scored.

RESULTS

The ascitic amylase levels on POD 3 were 1982 (1738-2249) IU/L in the C group and significantly lower at 136 (101-198) IU/L in the T group (p = 0.02). The ascitic lipase levels on POD 3 were 406 (265-478) U/L in the C group and significantly lower at 13 (7-17) U/L in the T group (p = 0.02). The intra-abdominal adhesion score on POD 3 was 2 (1-2) in the C group and significantly lower at 0 (0-1) in the T group (p = 0.02). The histological evaluation showed that the average of pancreatic inflammatory score was 8.5 (8-9) in the C group and significantly milder at 5 (5-7) in the T group (p = 0.01).

CONCLUSION

Our findings suggest that the triple-drug therapy could be useful as a treatment for PF in clinical settings.

Does the development of chronic kidney disease and acute kidney injury affect the prognosis after living donor liver transplantation?

BACKGROUND AND AIMS

Chronic kidney disease (CKD) and acute kidney injury (AKI) have been discussed as complications following living donor liver transplantation (LDLT). The aim of this study was to clarify the relationships among CKD, AKI, and the prognosis after LDLT.

METHODS

This study included 118 patients who underwent LDLT in our department. A low eGFR (<60 mL/min/1.73 m(2) ) was regarded to indicate CKD. AKI 1 and AKI 2 were characterized by an increase in the serum creatinine level of 0.5 and 1.0 mg/dL, respectively, within one wk after LDLT. We investigated the risk factors for and the relevance of CKD and AKI on the prognosis.

RESULTS

AKI 1 was associated with sepsis and intra-operative bleeding (p = 0.0032, p = 0.001). AKI 2 was associated with sepsis and hepatitis C infection (p < 0.001, p = 0.027). A pre-operative eGFR of 60-89 and diabetes were the risk factors for the development of CKD in POY 2 (p = 0.018, p = 0.002). AKI 2, sepsis, and diabetes were the risk factors for the patient death within one yr after LDLT (p = 0.010, p = 0.002, p = 0.022). AKI 2 and sepsis were the risk factors for death within two yr after LDLT (p = 0.005, p = 0.018).

CONCLUSIONS

Recognizing the risk factors and careful management for preventing both AKI and CKD may improve the prognosis of patients following LDLT.

Duodenal tubular resection using laparoscopic-endoscopic cooperative surgery: A new technique for the treatment of duodenal lesions

INTRODUCTION

Laparoscopic-endoscopic cooperative surgery (LECS) is a minimally invasive surgical technique that combines the advantages of laparoscopic surgery and endoscopic treatment. LECS has been developed for treatment of gastric submucosal tumors and can be applied to superficial non-ampullary duodenal tumors. Here we describe the use of LECS for duodenal mucosal cancer.

MATERIALS AND SURGICAL TECHNIQUE

After the placement of five ports, an endoscopic procedure was performed to confirm the tumor location and to place marks around the tumor. The jejunum was then resected 10 cm from the ligament of Treitz, and the connective tissue between the pancreas and duodenum was dissected to close to Vater's papilla. Duodenal resection was performed with a stapling device 2 cm to the oral side of the tumor, with endoscopic confirmation of the duodenal papilla, and duodenal tubular resection was then accomplished. Duodeno-jejunostomy was carried out using the same stapling device. There were no postoperative complications.

DISCUSSION

This case shows that duodenal tubular resection using LECS enables curability through a minimally invasive procedure that offers the advantages of laparoscopic surgery and endoscopic treatment. This technique is applicable to duodenal lesions such as those due to duodenal mucosal cancers.

Human Fibroblast Sheet Promotes Human Pancreatic Islet Survival and Function In Vitro

In previous work, we engineered functional cell sheets using bone marrow-derived mesenchymal stem cells (BM-MSCs) to promote islet graft survival. In the present study, we hypothesized that a cell sheet using dermal fibroblasts could be an alternative to MSCs, and then we aimed to evaluate the effects of this cell sheet on the functional viability of human islets. Fibroblast sheets were fabricated using temperature-responsive culture dishes. Human islets were seeded onto fibroblast sheets. The efficacy of the fibroblast sheets was evaluated by dividing islets into three groups: the islets-alone group, the coculture with fibroblasts group, and the islet culture on fibroblast sheet group. The ultrastructure of the islets cultured on each fibroblast sheet was examined by electron microscopy. The fibroblast sheet expression of fibronectin (as a component of the extracellular matrix) was quantified by Western blotting. After 3 days of culture, islet viabilities were 70.2 ± 9.8%, 87.4 ± 5.8%, and 88.6 ± 4.5%, and survival rates were 60.3 ± 6.8%, 65.3 ± 3.0%, and 75.8 ± 5.6%, respectively. Insulin secretions in response to high-glucose stimulation were 5.1 ± 1.6, 9.4 ± 3.8, and 23.5 ± 12.4 µIU/islet, and interleukin-6 (IL-6) secretions were 3.0 ± 0.7, 5.1 ± 1.2, and 7.3 ± 1.0 ng/day, respectively. Islets were found to incorporate into the fibroblast sheets while maintaining a three-dimensional structure and well-preserved extracellular matrix. The fibroblast sheets exhibited a higher expression of fibronectin compared to fibroblasts alone. In conclusion, human dermal fibroblast sheets fabricated by tissue-engineering techniques could provide an optimal substrate for human islets, as a source of cytokines and extracellular matrix.

Hybrid procedure in living donor liver transplantation

BACKGROUND

We have previously reported a hybrid procedure that uses a combination of laparoscopic mobilization of the liver and subsequent hepatectomy under direct vision in living donor liver transplantation (LDLT). We present the details of this hybrid procedure and the outcomes of the procedure.

METHODS

Between January 1997 and August 2014, 204 LDLTs were performed at Nagasaki University Hospital. Among them, 67 recent donors underwent hybrid donor hepatectomy. Forty-one donors underwent left hemihepatectomy, 25 underwent right hemihepatectomy, and 1 underwent posterior sectionectomy. First, an 8-cm subxiphoid midline incision was made; laparoscopic mobilization of the liver was then achieved with a hand-assist through the midline incision under the pneumoperitoneum. Thereafter, the incision was extended up to 12 cm for the right lobe and posterior sector graft and 10 cm left lobe graft procurement. Under direct vision, parenchymal transection was performed by means of the liver-hanging maneuver. The hybrid procedure for LDLT recipients was indicated only for selected cases with atrophic liver cirrhosis without a history of upper abdominal surgery, significant retroperitoneal collateral vessels, or hypertrophic change of the liver (n = 29). For total hepatectomy and splenectomy, the midline incision was sufficiently extended.

RESULTS

All of the hybrid donor hepatectomies were completed without an extra subcostal incision. No significant differences were observed in the blood loss or length of the operation compared with conventional open procedures. All of the donors have returned to their preoperative activity level, with fewer wound-related complaints compared with those treated with the use of the conventional open procedure. In recipients treated with the hybrid procedure, no clinically relevant drawbacks were observed compared with the recipients treated with a regular Mercedes-Benz-type incision.

CONCLUSIONS

Our hybrid procedure was safely conducted with the same quality as the conventional open procedure in both LDLT donors and recipients.

Increased expression of PHD3 represses the HIF-1 signaling pathway and contributes to poor neovascularization in pancreatic ductal adenocarcinoma

BACKGROUND

Pancreatic ductal adenocarcinoma (PDAC) is known as one of the most malignant potential diseases with poor neovascularization. By comparing PDAC to hepatocellular carcinoma (HCC), which is well vascularized, we investigated the mechanisms and tumor biological significance of the poor neovascularization in PDAC.

METHODS

Surgical specimens from primary PDAC and HCC patients were immunohistologically stained to detect the expressions of CD105, CD44, HIF-1α, PHD3, and Siah2. We also used two PDAC and two HCC cell lines to compare the expressions of HIF-1α, PHD3, and CD44, as well as the production of VEGF in hypoxic condition. The role of PHD3 in regulating HIF-1α expression was further confirmed by siRNA knockdown in a PDAC cell line that highly expressed PHD3.

RESULTS

There were significantly fewer microvessels but more cancer stem cells in PDAC specimens compared to HCC specimens. The expression of CD105 was reversely related to the expression of CD44 in PDAC and HCC specimens. PDAC specimens also showed higher expressions of PHD3 but lower expressions of HIF-1α. Similarly, the expression of PHD3 was observed clearly in PDAC cell lines, but was almost completely negative in HCC cell lines. Hypoxic stimulation clearly enhanced HIF-1α expression and VEGF secretion in both HCC cell lines, but did not significantly change in PDAC cell lines. The knockdown of PHD3 in PDAC cells restored the hypoxic-induced HIF-1α expression, which accordingly stimulated the cells' VEGF secretion.

CONCLUSIONS

The enhanced expression of PHD3 might likely contribute to the poor neovascularization and affect the biological characterization in PDAC cancer cells.

Prospective study of the safety and efficacy of intermittent inflow occlusion (Pringle maneuver) in living donor left hepatectomy

AIM

The impact of intermittent inflow occlusion (Pringle maneuver) in living donor hepatectomy on the outcome of both the donor and the recipient is unknown. The aim of this study is to elucidate the safety and efficacy of Pringle maneuver in living donor hepatectomy.

METHODS

Twenty consecutive cases of living donors who underwent left hepatectomy were prospectively divided into two groups, with (Group A, n = 10) or without (Group B, n = 10) the Pringle maneuver during hepatectomy. Intraoperative blood loss, postoperative liver functions in the donors and recipient outcome were reviewed.

RESULTS

Median blood loss was significantly less in group A than in group B. Median alanine aminotransferase was significantly higher on postoperative day 1 in group A than in group B, but the difference was not significant at 7 days after surgery. Eight of 10 recipients in each group survived with good graft function with a median follow-up period of 20 months in group A and 19 months in group B.

CONCLUSION

The Pringle maneuver was safely applied in living donor hepatectomy, but the only benefit was the reduction of blood loss during the donor surgery, and no positive impact on the recipient outcome.

A Method for Performing Islet Transplantation Using Tissue-Engineered Sheets of Islets and Mesenchymal Stem Cells

Mesenchymal stem cells (MSCs) are known to have a protective effect on islet cells. Cell sheets developed using tissue engineering help maintain the function of the cells themselves. This study describes a tissue engineering approach using islets with MSC sheets to improve the therapeutic effect of islet transplantation. MSCs were obtained from Fischer 344 rats and engineered into cell sheets using temperature-responsive culture dishes. The islets obtained from Fischer 344 rats were seeded onto MSC sheets, and the islets with MSC sheets were harvested by low-temperature treatment after coculture. The functional activity of the islets with MSC sheets was confirmed by a histological examination, insulin secretion assay, and quantification of the levels of cytokines. The therapeutic effects of the islets with MSC sheets were investigated by transplanting the sheets at subcutaneous sites in severe combined immunodeficiency (SCID) mice with streptozotocin-induced diabetes. Improvement of islet function and viability was shown in situ on the MSC sheet, and the histological examination showed that the MSC sheet maintained adhesion factor on the surface. In the recipient mice, normoglycemia was maintained for at least 84 days after transplantation, and neovascularization was observed. These results demonstrated that islet transplantation in a subcutaneous site would be possible by using the MSC sheet as a scaffold for islets.

The First Case of Deceased Donor Liver Transplantation for a Patient with End-Stage Liver Cirrhosis Due to Human Immunodeficiency Virus and Hepatitis C Virus Coinfection in Japan

We previously reported that progression of liver cirrhosis is quicker and survival is dismal in patients with human immunodeficiency virus (HIV) and hepatitis C virus (HCV) coinfection, especially when acquired in childhood through contaminated blood products. Recently, we performed the first deceased donor liver transplantation (DDLT) for an HIV/HCV-coinfected hemophilic patient in Japan. A 40-year-old man was referred to our hospital for liver transplantation. Regular DDLT was performed using the piggyback technique with a full-sized liver graft. Cold ischemia time was 465 min, and the graft liver weighed 1,590 g. The antiretroviral therapy (ART) was switched from darunavir/ritonavir to raltegravir before the transplant for flexible usage of calcineurin inhibitors postoperatively; tenofovir was used as the baseline treatment. The postoperative course was uneventful, and the patient was discharged home on day 43. He started receiving anti-HCV treatment on day 110 with pegylated interferon, ribavirin, and simeprevir after the DDLT. Herein, we report the first case of DDLT in Japan. Meticulous management of ART and clotting factors could lead to the success of DDLT.

Safety and efficacy of early drain removal and triple-drug therapy to prevent pancreatic fistula after distal pancreatectomy

OBJECTIVE

Prior studies suggested that early drain removal prevented the development of pancreatic fistula (PF) after pancreaticoduodenectomy (PD), but there has been no corresponding prospective trial for distal pancreatectomy (DP). The purpose of this study was to determine the safety and efficacy of early drain removal and triple-drug therapy (TDT) with gabexate mesilate, octreotide and carbapenem antibiotics to prevent PF after DP in patients at high-risk of developing PF.

METHODS

A total 71 patients who underwent a DP were enrolled. We prospectively divided them into two groups: the late-removal group, in which the drain remained in place for at least for 5 days postoperatively (n = 30) and the early-removal group in which the drain was removed on postoperative day 1 (POD1) (n = 41). For the patients with a high drain amylase level (≥10,000 IU/L) and patients with symptomatic intraperitoneal fluid collection, our original TDT was introduced. The primary endpoint was the safety and efficacy of this management, and the secondary endpoint was the incidence of PF.

RESULTS

The incidence of clinical PF was significantly lower in the early-removal group (0% vs. the late removal 16%; p < 0.001). In the early-removal group, TDT was administered to 12 patients (29%) and none of the patients needed additional treatment after TDT.

CONCLUSIONS

Postoperative management after DP with early drain removal and TDT was safe and effective for preventing PF.

E-cadherin expression in hepatocellular carcinoma treated with previous local treatment in patients undergoing living donor liver transplantation

BACKGROUND

The aim of this study was to evaluate the influence of previous local treatment on the E-cadherin (E-cad) expression in cases of hepatocellular carcinoma (HCC) after living donor liver transplantation (LDLT) within the Milan criteria.

METHODS

Seventy-four of 204 patients with HCC underwent LDLT between 1997 and 2014. Previous local treatment for HCC was performed for 121 lesions in 47 patients (47/74, 63.5%). Histological and immunohistochemical E-cad expression analyses were conducted on the basis of the whole-liver histological examination technique.

RESULTS

The interval to LDLT after the initial and last treatments was 24 months (2-206) and 10.5 months (1-58), respectively. Preoperative imaging showed necrosis in 92 (92/121, 76.0%) lesions caused by the effects of local treatment, whereas the histological examinations revealed viable HCC cells in 22 (22/92, 23.9%) lesions, demonstrating well or moderate differentiation without vascular invasion. Immunohistochemically, the expression of E-cad was maintained in 17 viable (17/22, 77.3%) lesions. There were no signs of malignant transformation or sarcomatous changes in the HCCs treated with previous therapy. The recipients who maintained an E-cad expression in the lesion with local treatment showed no recurrence or distant metastasis after LDLT.

CONCLUSIONS

HCC cells remained in approximately 20% of the evaluated lesions, even those exhibiting necrosis on imaging of the explanted cirrhotic liver. However, the expression of E-cad was maintained in most of these lesions. Furthermore, there were no significant differences in the rate of recurrence after LDLT between the patients who did and those did not receive previous local treatment for HCC.

Peritoneal recurrence of initially controlled hepatocellular carcinoma after living donor liver transplantation

It is well known that the presence of end-stage liver disease increases the risk of developing hepatocellular carcinoma (HCC). Liver transplantation (LT) for patients within the Milan criteria has become a standard treatment for HCC in most developed centers worldwide. However, a major cause of death in cirrhotic patients with HCC after transplantation is tumor recurrence, including peritoneal recurrences, which develops rarely but presents a significant problem with regard to their management. Our experience includes two cases with HCC within the Milan criteria of peritoneal recurrences after living donor LT. Both patients had interventions for HCC in their medical history before LT, and we propose that these might have been a possible cause of the HCC peritoneal recurrence.

A correlation between the graft volume evaluation and the prognosis in consideration of hepatic "compliance" in living donor liver transplantation

BACKGROUND/AIMS

The aim is to clarify the correlation between the hepatic compliance and prognosis of the patients who underwent LDLT.

METHODOLOGY

Volumetry was performed using a 3D volume analyzer. The hepatic compliance was evaluated based on the difference between the estimated total liver volume in the arterial phase and venous phase (n=66). The correlations among the hepatic compliance, donor background factors and the recipient's prognosis were evaluated.

RESULTS

Fourteen cases (21%) presented with a more than 5% increase in volume during the venous phase than in the arterial phase, and 12 of these recipients were still alive. There was a significant increase in death among recipients from donors age 60 years old and older (5/7, 71.4%, p<0.01). In these cases, the hepatic compliance was significantly different between the deceased cases and the surviving cases; while there was no hepatic compliance in the five deceased cases, favorable hepatic compliance was observed in two of the surviving cases (p<0.01).

CONCLUSIONS

Hepatic compliance appears to exist. The poor prognosis of liver grafts in recipients from elderly donors may be attributable to hepatic compliance, and assessing the hepatic compliance may be useful for preoperative liver graft evaluation.

Laparoscopic spleen-preserving distal pancreatectomy with and without splenic vessel preservation: the role of the Warshaw procedure

BACKGROUND/OBJECTIVES

Laparoscopic spleen-preserving distal pancreatectomy (LSPDP) for low-grade malignant pancreas tumors was recently demonstrated. Although the procedure with splenic vessel preservation (SVP) is optimal for LSPDP, SVP is not always possible in patients with a large tumor or a tumor attached to splenic vessels. This study aimed to analyze the safety of two procedures: LSPDP without SVP, known as the Warshaw technique (lap-WT), and LSPDP with SVP (lap-SVP).

METHODS

Seventeen patients who underwent a lap-WT and seven patients who underwent a lap-SVP were investigated retrospectively.

RESULTS

The median follow-up duration was 45 (range 17-105) months. In the lap-WT and lap-SVP patients, the sizes of the tumors were 5 (1.3-12) and 1.5 (1-4) cm; the operative times were 304 (168-512) and 319 (238-387) min; the blood loss was 210 (5-3250) and 60 (9-210) gr; the length of the postoperative hospital stay was 15 (8-29) and 18 (5-24) days; the peak platelet counts were 37.2 (14.6-65.2) and 26.4 (18.8-41) × 10(4)/μL, and splenomegaly was observed in 10 (59%) and three (43%) patients, respectively. In both procedures, there was no local recurrence. In the lap-WT group, splenic infarctions were seen in four (24%) patients and perigastric varices were seen in two (12%) patients. All of these patients were observed conservatively.

CONCLUSIONS

Both the lap-WT and lap-SVP were found to be safe and effective, and in cases in which the tumor is relatively large or close to the splenic vessels, lap-WT can be used as the more appropriate procedure.

How to explant a diseased liver for living donor liver transplantation after previous gastrectomy with severe adhesion (with video)

We performed living donor liver transplantation (LDLT) in a patient who had undergone distal gastrectomy for gastric ulcer disease with Billroth I reconstruction 30 years before the LDLT. The adhesion was very severe between remnant stomach and hepatic hilum as well as left liver lobe with shortening of hepatoduodenal structures. After dissection of the infrahepatic inferior vena cava, the Spiegel lobe was identified from the dorsal side. The Spiegel lobe was then penetrated with a right angle dissector so that a plastic tape could be placed around the whole adhesion, including important structures in the hepatoduodenal ligament. Next, the right hepatic vein was transected with a vascular stapler using Pringle's maneuver using the plastic tape to fasten the entire adhesional structure. Subsequently, the trunk of the middle and left hepatic vein was transected after clamping. The remaining short hepatic veins in the left side were divided completely from the cranial to the caudal direction to dissect Spiegel's lobe. Finally, the hepatoduodenal ligament was identified from the attached remnant stomach and the duodenum and a vascular clamp was placed on the entire hepatoduaodenal ligament. Finally, the diseased liver was explanted for graft implantation. Thus, retrograde explantation of the liver was effective in decreasing the risk of damaging vital elements in the hepatoduodenal ligament, the remnant stomach, and the duodenum.

Learning Curve for Laparoscopic Pancreaticoduodenectomy: A Single Surgeon's Experience with Consecutive Patients

BACKGROUND/AIMS

Laparoscopic pancreaticoduodenectomy (LPD) is regarded as one of the most complex surgical procedures. The aim of this study was to examine a single surgeon's learning curve for LPD in consecutive cases.

METHODOLOGY

Thirty consecutive patients who underwent an LPD by the same single surgeon were divided into three groups (A, B, and C; 10 cases each). Postoperative complications, operative time, and blood loss for each group were compared.

RESULTS

There were no significant differences in the occurrence of postoperative complications among the groups. There were significant differences in both operative time and blood loss between groupA (mean operative time, 796.8 mm; mean blood loss 546.2 mL) and group B (mean operative time, 563.9 mm; mean blood loss 242.0 mL), and between groups A and C (mean operative time, 515.8 mm; mean blood loss 283.0 mL). Regarding operative time and blood loss, the surgeon reached a learning curve plateau after 10 cases/LPD procedures.

CONCLUSIONS

LPD is a feasible and safe surgical procedure with a steep learning curve when performed by a surgeon who is experience in open PD, and LPD provides the advantages that would be expected from a minimally invasive surgery.

[Acoustic radiation force impulse elastography for liver disease staging in human immunodeficiency virus and hepatitis C virus co-infection]

BACKGROUND

Survival of human immunodeficiency virus (HIV)-infected patients has improved due to the widespread use of anti-retroviral therapy. However, mortality has increased when HIV-infected patients are co-infected with hepatitis C virus (HCV), and the liver disease in such patients is rapidly progressive compared with that in HCV monoinfected patients. Therefore, accurate staging of the liver disease is critical when determining appropriate treatment.

AIM

To clarify the efficacy of acoustic radiation force impulse (ARFI) elastography for the evaluation of liver fibrosis and hepatic functional reserve in HIV/HCV co-infected patients.

METHODS

The correlation of shear wave velocity (Vs), measured by ARFI elastography, with liver fibrosis or hepatic functional reserve was analyzed.

RESULTS

Vs was significantly correlated with platelet count, splenic volume, hyaluronic acid, type IV collagen, and LHL15 (receptor index: uptake ratio of the liver to the liver plus heart at 15min) in 99mTc-GSA (technetium-99m-diethylenetriaminepentaacetic acid-galactosyl human serum albumin) scintigraphy.

CONCLUSION

ARFI elastography was useful for the staging of liver disease in HIV/HCV co-infected patients and it facilitated minimally invasive and accessible evaluation of fibrosis and functional reserve.

Single-incision laparoscopic distal pancreatectomy: our initial experience

BACKGROUND/AIMS

Single-incision laparoscopic surgery (SILS) is gaining popularity as a minimally invasive surgery. However, SILS distal pancreatectomy (SILS-DP) remains a challenging surgical procedure. In this study, we describe our initial experience with five cases of SILS-DP.

METHODOLOGY

We present an initial series of SILS-DP, performed between August 2010 and January 2013.

RESULTS

Five patients successfully underwent SILS-DP. The median operative time was 264 min (range, 232-345 min). The median intraoperative blood loss was 71 cc (range, 5-200 cc). All the patients left the hospital in good condition after SILS-DP.

CONCLUSIONS

Although SILS-DP is a safe, feasible, and esthetic procedure, a randomized controlled study is required to determine the advantages of SILS-DP in comparison with the standard laparoscopic method.

Endoscopic transpapillary pancreatic stenting for internal pancreatic fistula with the disruption of the pancreatic ductal system

BACKGROUND

Internal pancreatic fistula (IPF) is a well-recognized complication of pancreatic diseases. Although there have been many reports concerning IPF, the therapy for IPF still remains controversial. We herein report our experiences with endoscopic transpapillary pancreatic stent therapy for IPF and evaluate its validity.

METHOD

Six patients with IPF who presented at our department and received endoscopic transpapillary pancreatic stent therapy were investigated, focusing on the clinical and imaging features as well as treatment strategies, the response to therapy and the outcome.

RESULTS

All patients were complicated with stenosis or obstruction of the main pancreatic duct, and in these cases the pancreatic ductal disruption developed distal to the areas of pancreatic stricture. The sites of pancreatic ductal disruption were the pancreatic body in five patients and the pancreatic tail in one patient. All patients received endoscopic stent placement over the stenosis site of the pancreatic duct. Three patients improved completely and one patient improved temporarily. Finally, three patients underwent surgical treatment for IPF. All patients have maintained a good course without a recurrence of IPF.

CONCLUSION

Endoscopic transpapillary pancreatic stent therapy may be an appropriate first-line treatment to be considered before surgical treatment. The point of stenting for IPF is to place a stent over the stenosis site of the pancreatic duct to reduce the pancreatic ductal pressure and the pseudocyst's pressure.

Decreased expression of SOX9 in intraductal papillary mucinous neoplasms of the bile duct

BACKGROUND/AIMS

SOX9 is an important transcription factor required for development and has been implicated in several types of malignant tumor. Our recent study showed that SOX9 played an important role in multi-step carcinogenesis in cases of intraductal papillary mucinous tumor of the pancreas (IPMN-P). This study aimed to investigate the expression of SOX9 in cases of intraductal papillary mucinous tumor of the bile duct (IPMN-B).

METHODOLOGY

SOX9 expression was immunohistochemically evaluated in the tumor and corresponding normal bile-duct epithelium of seven IPMN-B patients.

RESULTS

In all cases, SOX9 expression in the IPMN-B was low compared with the normal biliary epithelium.

CONCLUSIONS

This study demonstrated that SOX9 expression may indicate a link between IPMN-B and IPMN-P. SOX9 may also have potential as a therapeutic target and/or prognostic marker in IPMN-B.

Evaluation of immune function under conversion from Prograf to Advagraf in living donor liver transplantation

BACKGROUND

Although some reports have shown the safety and efficacy of conversion from Prograf to Advagraf in liver transplantation, there have been no reports showing the change of immune function after conversion. The aim of this study is not only to analyze the safety and efficacy of conversion from Prograf to Advagraf, but also to evaluate the immune function using the ImmuKnow assay.

MATERIAL AND METHODS

Of the 168 living donor liver transplantation (LDLT) patients, 21 recipients whose liver function was stable after discharge in outpatient clinic and who agreed to conversion from Prograf to Advagraf were enrolled in this study. Liver, renal, and immune functions were retrospectively reviewed.

RESULTS

There were no significant differences in liver and renal function after conversion from Prograf to Advagraf. The intracellular adenosine triphosphate levels before and after conversion were 263±157 and 256±133 ng/ml, respectively, and there was also no significant difference in immune function. None of the recipients showed adverse effects, rejection, or severe infection during the study. It should be further noted that none of the recipients had to increase the dose of Advagraf, while five of 21 recipients (24%) were able to reduce the dose of Advagraf during this study.

CONCLUSIONS

Conversion from Prograf to Advagraf in LDLT can be performed safely and effectively without affecting liver, renal, and immune function.

Combined resection for multifocal lesions of the pancreas

BACKGROUND/AIMS

Multifocal lesions of the pancreas generally require a total pancreatectomy. However, total pancreatectomy causes severe and permanent pancreatic endocrine and exocrine insufficiency. The aim of this study was to review our experiences of combined resection of the pancreas as an alternative to total pancreatectomy.

METHODOLOGY

From July 2004 to July 2011, 5 patients were indicated to undergo combined resection for multiple lesions of the pancreas at our institution.

RESULTS

The surgical procedures for combined resection of the pancreas in the 5 patients consisted of various limited resections of the pancreas. No patient developed insulin-dependent diabetes mellitus. In addition, no patient developed exocrine insufficiency after pancreatic resection.

CONCLUSIONS

For multifocal lesions of the pancreas, combined resection of the pancreas should be considered the surgical procedure of choice to reduce the risk of both endocrine and exocrine insufficiency.

Laparoscopic middle pancreatectomy under a pancreatic duct-navigation surgery

Recent developments of diagnostic modalities have increased detection of many benign and low malignant pancreatic lesions, and then various minimally invasive surgeries and/or pancreatic function preserving surgeries have been devised for such lesions. Laparoscopic pancreatic surgery has developed rapidly in recent years, and its minimal invasiveness is expected. This report describes a laparoscopic middle pancreatectomy under a pancreatic duct-navigation surgery for a localized main pancreatic duct stenosis, and this method is effective to benign and low malignant pancreatic lesions in the points of minimal invasiveness and function preservation.

Peritoneal and nodal recurrence 7 years after the excision of a ruptured solid pseudopapillary neoplasm of the pancreas: report of a case

A solid pseudopapillary neoplasm (SPN) of the pancreas is generally regarded as a neoplasm of low malignant potential and there is rarely recurrence of the disease. A 12-year-old female underwent a pylorus preserving pancreaticoduodenectomy for a ruptured pancreatic SPN following a blunt abdominal trauma. The tumor showed no pathological features suggesting malignant potential. Follow-up imaging studies depicted small nodules adjacent to the superior mesenteric vein 7 years after surgery. A laparotomy was performed, and exploration revealed 3 nodules adjacent to the superior mesenteric vein and 4 small nodules in the mesointestine. All of these lesions were extirpated, and were histologically confirmed to be nodal and peritoneal recurrence of SPN. This case indicates that SPN of the pancreas has a latent ability to recur, regardless of its benign pathological features, and peritoneal spread may be promoted by trauma. A close postoperative follow-up is thus mandatory in all patients with SPN even after a radical resection.

Surgical strategy for main pancreatic duct-type intraductal papillary mucinous neoplasm of the pancreas

BACKGROUND/AIMS

Although surgical resection is recommended for all main duct-type intraductal papillary mucinous neoplasms (IPMNs), controversies remain over the precise surgical strategy that should be adopted. This study thus aimed to investigate the appropriate surgical strategy for main duct IPMNs.

METHODOLOGY

We retrospectively evaluated 46 patients with main duct-type IPMNs who underwent surgical resection at a single center between 1991 and 2010.

RESULTS

Only 1 patient underwent total pancreatectomy (TP). Three patients underwent repeated pancreatectomy; TP was performed after distal pancreatectomy (DP) in 2 of these patients and after pylorus-preserving pancreaticoduodenectomy (PPPD) in the remaining patient. There current histology indicated minimally invasive carcinoma in all 3 of these patients. Among the 6 patients who died in the present study, no deaths occurred due to local recurrence of the remnant pancreas.

CONCLUSIONS

Total pancreatectomy should be considered very selectively in the presence of a malignant lesion spreading to the whole pancreas.

Gastric rupture with necrosis following acute gastric dilatation: report of a case

Gastric rupture with necrosis following acute gastric dilatation (AGD) is a rare and potentially fatal event; usually seen in patients with eating disorders such as anorexia nervosa or bulimia. A 12-year-old lean boy with no remarkable medical history was brought to our Emergency Department suffering acute abdominal symptoms. Emergency laparotomy revealed massive gastric dilatation and partial necrosis, with rupture of the anterior wall of the fundus of the stomach. We performed partial gastrectomy and the patient recovered uneventfully. We report this case to demonstrate that AGD and subsequent gastric rupture can occur in patients without any underlying disorders and that just a low body mass index is a risk factor for this potentially fatal condition.

Marionette method for transumbilical single-incision, two-trocar laparoscopic cholecystectomy: a new, simple technique

BACKGROUND/AIMS

Single-incision laparoscopic cholecystectomy (SILC) has recently become a topic of interest among types of minimally invasive surgery.

METHODOLOGY

We developed a novel "marionette method"technique for performing SILC. Two 5 mm trocars were placed through a 1.5 cm transumbilical incision. In addition, a nylon suture with a laparoscopic sliding knot was used to tighten the fundus of the gallbladder and was thereafter suspended with this nylon suture. The neck of the gallbladder was tightened by means of a loop type retractor, to enable adequate visualization of the triangle of Calot. Dissection was performed as a conventional laparoscopic cholecystectomy using standard straight laparoscopic instruments.

RESULTS

All 20 patients successfully underwent a single-incision, two-trocar laparoscopic cholecystectomy performed using the marionette method. The mean operative time was 119 min. There were no complications.

CONCLUSIONS

The marionette method can provide good tension and an appropriate laparoscopic view with a suitable surgical field for safely performing a dissection at the triangle of Calot during SILC.

Placement of a plastic biliary stent tube with primary closure of the common bile duct after laparoscopic common bile duct exploration

Laparoscopic common bile duct exploration (LCBDE) is one of the standard surgical procedures for treating choledocholithiasis. Several methods of biliary drainage following LCBDE have been advocated to prevent bile leakage. We report herein a surgical procedure using a plastic biliary stent tube following LCBDE for biliary drainage. Our method is technically simple, feasible and an ideal procedure for biliary drainage with LCBDE.

Limited pancreatectomy for metastatic pancreatic tumors from renal cell carcinoma

BACKGROUND/AIMS

Metastasis of renal cell carcinoma (RCC) to distant organs occurs commonly, even after radical nephrectomy, but metastatic lesions are rarely detected in the pancreas. The present study aim was to improve the postoperative quality of life of a patient with pancreatic metastasis of RCC through limited resection of the pancreas.

METHODOLOGY

Since therapeutic modalities including chemotherapy or radiation are ineffective for metastatic tumors, surgical intervention is a treatment of choice in selected patients. In patients with multiple pancreatic metastases, however, near-total or total pancreatectomy may result in a lower quality of life postoperatively due to endocrine and exocrine pancreatic insufficiency.

RESULTS

We used limited resection of the pancreas combined with removal of the uncinate process and distal pancreatectomy for a 65-year-old woman with multifocal pancreatic metastases located in the uncinate process, body, and tail of the pancreas, which were detected 6 years after radical nephrectomy for RCC. This surgical procedure allowed preservation of about 40% of the pancreatic parenchyma, with complete excision of metastatic tumors in the pancreas.

CONCLUSIONS

The patient has had an excellent quality of life with well-preserved pancreatic function and no evidence of tumor recurrence for 31 months after pancreatic surgery.

Chemopreventative effect of an inducible nitric oxide synthase inhibitor, ONO-1714, on inflammation-associated biliary carcinogenesis in hamsters

The present study was designed to investigate whether an inducible nitric oxide synthase (iNOS)-specific inhibitor, ONO-1714 [(1S, 5S, 6R, 7R)-7-chloro-3-imino-5-methyl-2-azabicyclo[4.1.0] heptane], could prevent inflammation-associated biliary carcinogenesis in bilioenterostomized hamsters. Syrian golden hamsters underwent choledochojejunostomy and then received subcutaneous injections of the chemical carcinogen N-nitrosobis(2-oxopropyl)amine every 2 weeks at a dose of 10 mg/kg body wt, starting 4 weeks after surgery and continuing for 18 weeks. The hamsters were divided into two groups according to their oral intake of either a standard pelleted diet containing ONO-1714 at 100 p.p.m. for 18 weeks (ONO group, n = 15) or an ordinary diet alone (control group, n = 15). The animals were killed 22 weeks after surgery, and the development of biliary tumors was examined histologically. The presence and degree of cholangitis, cell kinetic status of the biliary epithelium and iNOS expression were evaluated. Intrahepatic biliary adenomas developed in all control animals, whereas they developed in only seven (47%) hamsters treated with ONO-1714 (P < 0.05). Intrahepatic biliary carcinomas were present in 13 (87%) hamsters in the control group and in only 6 (40%) hamsters in the ONO groups (P < 0.05). Histological and immunohistochemical examinations demonstrated a significant decrease in the degree of cholangitis, biliary epithelial cell kinetics and the expression of iNOS in the biliary epithelium in the ONO group in comparison with the control (P < 0.05). These results indicate that ONO-1714 represses N-nitrosobis(2-oxopropyl)amine-induced biliary carcinogenesis in bilioenterostomized hamsters and inhibits iNOS expression in the biliary epithelium. ONO-1714 may therefore be a promising agent for the prevention of biliary carcinoma in various inflammation-associated biliary disorders.