Hirofumi Kawamoto

Differences between right- and left-sided colon cancer in patient characteristics, cancer morphology and histology.

Background and Aim:  Recently, the clinical and biological differences between right‐ and left‐sided colon cancers have been widely debated. However, close analyses of these clinical differences, based on large‐scale studies, have been scarcely reported.

Multicenter retrospective study of endoscopic ultrasound-guided biliary drainage for malignant biliary obstruction in Japan

Endoscopic ultrasound‐guided biliary drainage (EUS‐BD) is considered to be an effective salvage procedure for failed endoscopic retrograde cholangiopancreatography in patients with unresectable malignant biliary obstruction. The aim of this retrospective study was to evaluate the efficacy and feasibility of EUS‐BD.

COMBINED DUODENAL STENT PLACEMENT AND ENDOSCOPIC ULTRASONOGRAPHY-GUIDED BILIARY DRAINAGE FOR MALIGNANT DUODENAL OBSTRUCTION WITH BILIARY STRICTURE

Patients with malignant pancreatobiliary neoplasm sometimes manifest duodenal obstruction and biliary stricture synchronously or metachronously. In this paper, we reviewed our experience with and technique for combined endoscopic duodenal stent placement and endoscopic ultrasonography (EUS)‐guided biliary drainage. Between May 2007 and September 2009, this combined technique was performed on seven patients with distal biliary strictures and duodenal obstructions. The clinical success rate of the procedure, complications, patency periods of duodenal stents and patency periods of biliary stents were retrospectively evaluated. Clinical success was achieved in all seven cases for both procedures. Complications related to EUS‐biliary drainage, namely localized peritonitis due to bile leakage, occurred in two cases. Both patients recovered without additional interventions. Occlusion of a duodenal stent was observed in one patient, but additional intervention could not be performed due to sepsis. Occlusion of both a duodenal stent and a biliary stent was also observed in one patient, and this was resolved with the insertion of an additional duodenal stent and a biliary stent exchange. In conclusion, combined duodenal stent placement and EUS‐guided biliary drainage is a therapeutic option in case of failed endoscopic retrograde cannulation of malignant strictures with a malignant duodenal obstruction.

Comparison of partially covered nitinol stents with partially covered stainless stents as a historical control in a multicenter study of distal malignant biliary obstruction: the WATCH study

BACKGROUND Covered self-expandable metal stents (CSEMSs) were developed to prevent tumor ingrowth, but stent migration is one of the problems with CSEMSs. OBJECTIVE To evaluate a new, commercially available CSEMS with flared ends and low axial force compared with a commercially available CSEMS without the anti-migration system and high axial force. DESIGN Multicenter, prospective study with a historical cohort. SETTING Twenty Japanese referral centers. PATIENTS This study involved patients with unresectable distal malignant biliary obstruction. INTERVENTION Placement of a new, commercially available, partially covered SEMS. MAIN OUTCOME MEASUREMENTS Recurrent biliary obstruction rate, time to recurrent biliary obstruction, stent-related complications, survival. RESULTS Between April 2009 and March 2010, 141 patients underwent partially covered nitinol stent placement, and between May 2001 and January 2007, 138 patients underwent placement of partially covered stainless stents as a historical control. The silicone cover of the partially covered nitinol stents prevented tumor ingrowth. There were no significant differences in survival (229 vs 219 days; P = .250) or the rate of recurrent biliary obstruction (33% vs 38%; P = .385) between partially covered nitinol stents and partially covered stainless stents. Stent migration was less frequent (8% vs 17%; P = .019), and time to recurrent biliary obstruction was significantly longer (373 vs 285 days; P = .007) with partially covered nitinol stents. Stent removal was successful in 26 of 27 patients (96%). LIMITATIONS Nonrandomized, controlled trial. CONCLUSION Partially covered nitinol stents with an anti-migration system and less axial force demonstrated longer time to recurrent biliary obstruction with no tumor ingrowth and less stent migration.

Long-term outcomes of endoscopic management for biliary strictures after living donor liver transplantation with duct-to-duct reconstruction

Biliary strictures after living donor liver transplantation (LDLT) with duct‐to‐duct (D‐D) reconstruction are associated with postoperative morbidity and mortality. The aims of this study were to evaluate the long‐term outcomes of endoscopic deployment of plastic stents, and to investigate factors associated with the stent deployment failure. Between April 2001 and May 2007, 96 patients received LDLT with D‐D reconstruction at Okayama University Hospital. Among them, 41 patients (43%) had anastomotic biliary strictures, and all were referred first for endoscopic retrograde cholangiography (ERC). When deployment was unsuccessful, a percutaneous transhepatic procedure was employed. Successful stent deployment was achieved in 35 out of total 41 patients (85%) by both procedures. Among the 35 patients, 28 had their stents removed as a result of strictures resolution. Eight patients underwent ERC and repeated stent deployment as a result of recurrence of the strictures. Finally, 21 out of 41 (51%) patients with biliary stricture were completely treated by endoscopic therapy during the observation period (median 873 days: range 77–2060). By multivariate analysis, biliary leakage was associated with stent deployment failure. Endoscopic deployment of plastic stents is a first‐line therapy for patients with biliary stricture after LDLT.

Endoscopic deployment of multiple JOSTENT SelfX is effective and safe in treatment of malignant hilar biliary strictures.

BACKGROUND & AIMS For the treatment of unresectable biliary tract carcinoma with hilar biliary stricture, antitumor therapy and biliary stenting should be addressed in terms of prolonged survival with a good quality of life. However, the endoscopic management of malignant hilar biliary strictures is difficult even for an expert endoscopist. We evaluated the efficacy and safety of the endoscopic deployment of multiple JOSTENT SelfX units in patients with hilar biliary strictures treated with or without chemotherapy. METHODS Between November 2003 and December 2006, endoscopic deployment of multiple JOSTENT SelfX units in hilar biliary strictures by using a partial stent-in-stent procedure was performed on 41 consecutive patients with primary cholangiocarcinoma (n = 34) and gallbladder carcinoma (n = 7) at a gastroenterologic center of Okayama University Hospital. Thirty-three patients were treated with gemcitabine (n = 25) or S-1 (n = 8). RESULTS Metallic stent deployment was successfully accomplished in all cases via only endoscopic procedures. During the follow-up period (mean, 210 days), mean patency time was 150 days, and metallic stent obstruction occurred in 15 cases (37%). Although a repeat intervention was required in all metallic stent obstructed cases, the deployment of the second metallic or plastic stent was completed successfully. The remaining 26 cases (63%) required no interventions. The median overall survival period was only 235 days. However, that of the patients receiving chemotherapy was 392 days. CONCLUSIONS Endoscopic partial stent-in-stent deployment with multiple JOSTENT SelfX prostheses is effective and safe for the treatment of malignant hilar biliary stricture even in patients receiving chemotherapy.

Prevention of biliary complication in radiofrequency ablation for hepatocellular carcinoma—Cooling effect by endoscopic nasobiliary drainage tube

BACKGROUND AND STUDY AIMS Biliary stricture after radiofrequency ablation (RFA) for nodules of hepatocellular carcinoma (HCC) close to major bile ducts sometimes causes septic complications and liver failure. Therefore, it may require interventional drainage for decompression during the follow-up period. The purpose of this study is to clarify the feasibility and safety of bile duct cooling using an endoscopic nasobiliary drainage (ENBD) tube in RFA for HCC close to major bile ducts. PATIENTS AND METHODS Between August 2003 and July 2007, 14 consecutive patients (14 nodules) undergoing RFA with cooling by an ENBD tube for HCCs close to major bile ducts were enrolled in this study. We infused chilled saline solution via the ENBD tube at 1ml/s to prevent heat damage during RFA. As controls, 11 patients (13 nodules) undergoing RFA without cooling close to major bile ducts between April 2001 and August 2003 were reviewed. The major outcomes for evaluation were biliary complications and the secondary outcome was local tumor recurrence. RESULTS There were no significant differences in tumor recurrence between the two groups. However, the rate of biliary complications was significantly lower in the cooling group than in the non-cooling group (0% vs. 39%, P=0.02). CONCLUSIONS Cooling of bile ducts via an ENBD tube can prevent biliary complications induced by RFA of HCC close to major bile ducts without increasing local recurrence. This technique increases indication of RFA in difficult cases.

Vascular patterns in nodules of intraductal papillary mucinous neoplasms depicted under contrast-enhanced ultrasonography are helpful for evaluating malignant potential

OBJECTIVES The purpose of this study is to evaluate the feasibility of contrast-enhanced ultrasonography (CE-US) to differentiate between benign and malignant intraductal papillary mucinous neoplasms (IPMN). PATIENTS AND METHODS Contrast-enhanced ultrasonography with a contrast agent was performed on 22 consecutive patients with IPMN suspected of being malignant. This revealed 10 carcinomas, 1 borderline lesion and 11 adenomas. All patients underwent surgery, and the histological diagnosis was confirmed by examination of resected specimens. CE-US was performed using a contrast agent. The detection rates of mural nodules were compared between CE-US and contrast-enhanced computed tomography (CE-CT), and the imaging of mural nodules depicted under CE-US was analyzed. RESULTS Seventeen of 22 resected specimens (77.3%) had mural nodules. There was no significant difference in the detection rate between CE-US (n=15; 88.2%) and CE-CT (n=12; 70.6%). In 12 (80.0%) of these patients, CE-US revealed small vessels in the mural nodule. The spotty or linear-shaped pattern was detected in 4 patients and the branch-shaped pattern in 8. The branch-shaped pattern lesion was associated with carcinoma. These mural nodules were 10mm or more in height. In the perfusion image phase, cystic walls and mural nodules were also enhanced in all cases. CONCLUSION The vessel shapes of the mural nodules depicted under CE-US were associated with size and pathological findings. These results suggested that CE-US with a contrast agent is a powerful modality with which to evaluate the malignant potential of IPMN.

Clinical significance of B cell-activating factor in autoimmune pancreatitis.

Objectives: Overexpression of B Cell-activating factor (BAFF) is involved in autoimmunity, but little is known about its role in autoimmune pancreatitis (AIP). The aim of this study was to investigate the role of BAFF in the diagnosis and pathogenesis of AIP. Methods: Patients with AIP (n = 19) were compared with 2 disease control groups (chronic pancreatitis [n = 17] and pancreatic cancer [n = 15]) and a healthy subject group (n = 19). Serum BAFF levels were assessed using an enzyme-linked immunosorbent assay. The expressions of BAFF and BAFF receptor in the pancreatic tissue of patients with AIP were estimated using immunohistochemistry. Results: Mean serum BAFF levels were higher in the patients with AIP than in the patients with chronic pancreatitis, the patients with pancreatic cancer, and the healthy subjects (P < 0.0001 for all groups). Using the cutoff value of 1389 pg/mL, the sensitivity and specificity to differentiate AIP from disease and healthy controls were 89.5% and 92.2%, respectively. Glucocorticoid therapy decreased serum BAFF levels below 1389 pg/mL in all patients with AIP (P < 0.0001). B Cell-activating factor and BAFF receptor were expressed on cells infiltrating the pancreas of patients with AIP. Conclusions: B Cell-activating factor could be a novel marker for diagnosis and treatment response in AIP and may contribute to its pathogenesis.

Pachydermoperiostosis associated with juvenile polyps of the stomach and gastric adenocarcinoma

Pachydermoperiostosis (PDP) is a rare syndrome, and the presence of digital clubbing, radiographic periostosis, and coarse facial features are the main diagnostic criteria. Here, we report patient with the primary form of PDP in whom juvenile polyps and gastric cancer developed within 9 years of follow-up. A 27-year-old Japanese man, diagnosed as having the primary form of PDP at 14 years of age, was referred to our department for assessment of chronic anemia. On upper gastrointestinal endoscopic examination, multiple polypoid lesions with a huge polyp were found in the stomach, and biopsy findings indicated juvenile polyps, although no polypoid lesion had been present at the age of 18 years. Bleeding from these polyps was suspected, and endoscopic mucosal resection of the polypoid lesions was performed. Histology of the huge polyp showed hamartoma, adenoma, and adenocarcinoma in part. This is the first case report of the primary form of PDP associated with gastric cancer. In this patient, juvenile polyps and gastric cancer developed within 9 years of follow-up, indicating that the primary form of PDP may be a high risk factor for gastric cancer, and that periodical follow-up with upper gastrointestinal endoscopy is important.