Suguru Mizuno

Preliminary report on a new, fully covered, metal stent designed for the treatment of pancreatic fluid collections

BACKGROUND Endoscopic transluminal treatment of pancreatic fluid collections (PFC) has been reported as an effective alternative approach to surgical treatment. A wide, short stent with an anti-migration system has been developed. OBJECTIVE To evaluate a newly developed, fully covered, self-expandable metal stent (FCSEMS) customized for cystogastrostomy. DESIGN Retrospective case series. SETTING Tertiary-care academic medical centers and affiliated hospitals. PATIENTS Nine patients who underwent endoscopic treatment of PFCs (5 with pseudocysts and 4 with walled-off pancreatic necrosis). INTERVENTION Stent deployment after endoscopic US-guided puncture. Irrigation and necrosectomy were performed at the discretion of the endoscopist. MAIN OUTCOME MEASUREMENTS Technical and clinical success rate, complications, and removability. RESULTS The FCSEMS was inserted successfully in all cases (9/9, 100%). Clinical success was achieved in 7 of 9 cases (77.8%). No early complications associated with the procedure were observed. Late complications were observed in 2 cases (bleeding and asymptomatic migration). The FCSEMS was removed without any complications in all 6 cases where it was attempted after the procedure had been completed (100%). LIMITATIONS This was a retrospective evaluation of a small number of cases. The FCSEMS was always inserted via the transgastric route. Follow-up duration was short. CONCLUSION The endoscopic approach that uses this new FCSEMS is feasible for the treatment of PFCs. However, further evaluation is required.

Diagnostic utility of biopsy specimens for autoimmune pancreatitis

Background and aimsInfiltration of IgG4-positive plasma cells in the pancreas and other organs is characteristic of autoimmune pancreatitis (AIP). However, it is undetermined whether needle or forceps biopsy of pancreas or other organs is indeed useful for the diagnosis of AIP. We aimed to clarify this point.MethodsAmong 39 AIP patients, tissue sampling without laparotomy was performed in 27. Biopsy of pancreas, gastric mucosa, liver, bile duct, and duodenal papilla was performed in 15, 17, 11, 5 and 7, respectively. The obtained specimens were examined for IgG4-positive plasma cells. We also examined gastric mucosa of 18 patients with pancreatic cancer as controls. When the number of IgG4-positive plasma cells was more than 10 per high-power field, we regarded it as diagnostic.ResultsDiagnostic sensitivity in pancreas, gastric mucosa, liver, bile duct, and duodenal papilla was 47% (7/15), 47% (8/17), 36% (4/11), 0% (0/5), and 57% (4/7), respectively.ConclusionsSensitivity of IgG4 immunostaining was unsatisfactory when tissue sampling was performed by needle or forceps biopsy. Biopsy of gastric mucosa might be a good subsidiary diagnostic tool.

Endoscopic evaluation of factors contributing to intrapancreatic biliary stricture in autoimmune pancreatitis

BACKGROUND Intrapancreatic bile duct stricture in autoimmune pancreatitis (AIP) is usually diagnosed as sclerosing cholangitis even if the stricture is limited to the intrapancreatic area. However, it is not known whether compression caused by pancreatic edema or biliary wall thickening causes such a biliary stricture. OBJECTIVE Our purpose was to clarify the factor that contributes to intrapancreatic biliary stricture in AIP: pancreatic head lesion or biliary wall thickening. DESIGN Single-center retrospective study. SETTING This study was performed in a tertiary care academic medical center. PATIENTS Fifty-six patients with AIP were included. MAIN OUTCOME MEASUREMENTS The relationship between the presence of a pancreatic head lesion and intrapancreatic biliary stricture was examined. In addition, the relationship between the extent of the intrapancreatic biliary stricture and the wall thickening was evaluated. RESULTS Among 44 patients with a pancreatic head lesion, 41 (93%) had intrapancreatic bile duct stricture. Among 12 patients without a pancreatic head lesion, only 2 had such a stricture (P < .0001). Intraductal US showed average intrapancreatic biliary wall thickening with severe stricture of 2.7 +/- 1.0 mm, significantly thicker than that with mild stricture (1.9 +/- 0.35 mm; P = .0200). LIMITATIONS Intraductal US was not performed in all patients. CONCLUSIONS Both pancreatic edema and biliary wall thickening influenced intrapancreatic biliary stricture in AIP. This type of stricture should be differentiated from extrapancreatic biliary stricture that may be caused by biliary wall thickening only.

Japanese multicenter estimation of wallflex duodenal stent for unresectable malignant gastric outlet obstruction

This retrospective study estimated the efficacy and safety of the WallFlex duodenal stent for malignant gastric outlet obstruction (GOO) in Japan.

Duodenal invasion is a risk factor for the early dysfunction of biliary metal stents in unresectable pancreatic cancer.

BACKGROUND Although the placement of self-expandable metal stents (SEMSs) has been widely accepted as palliation for distal malignant biliary obstruction, the risk factors for their early dysfunction remain unclear. OBJECTIVE To identify risk factors for early (<3 months) SEMS dysfunction in unresectable pancreatic cancer. DESIGN A multicenter retrospective study. SETTING Five tertiary referral centers. PATIENTS Patients were included who underwent first-time SEMS placement for distal malignant biliary obstruction caused by pancreatic cancer between April 1994 and August 2010. MAIN OUTCOME MEASUREMENTS Rates and causes of early dysfunction were evaluated, and risk factors were analyzed. RESULTS In all, 317 eligible patients were identified. Covered SEMSs were placed in 82% of patients. Duodenal invasion was observed endoscopically in 37%. The median time to dysfunction was 170 days. The rates of all and early SEMS dysfunction were 55% and 31%, respectively. The major causes of SEMS dysfunction were food impaction and nonocclusion cholangitis (21% each) in early dysfunction and sludge (29%) in nonearly dysfunction. The rate of early dysfunction was 42% with duodenal invasion and 24% without duodenal invasion (P = .001). Early dysfunction caused by food impaction was more frequent in patients with duodenal invasion (10% and 4%, P = .053). Duodenal invasion was a risk factor (odds ratio 2.35; 95% CI, 1.43-3.90; P = .001) in a multiple logistic regression model. LIMITATIONS A retrospective design. CONCLUSIONS Duodenal invasion is a risk factor for early SEMS dysfunction in patients with pancreatic cancer.

Clinical Outcomes of Chemotherapy for Diabetic and Nondiabetic Patients With Pancreatic Cancer: Better Prognosis With Statin Use in Diabetic Patients.

Objectives The aim of this study was to clarify the impact of diabetes mellitus (DM) as well as antidiabetic, antihypertensive, and antihyperlipidemic medications such as metformin and statins on survival in patients with advanced pancreatic cancer receiving chemotherapy. Methods We retrospectively reviewed the medical records of 250 patients with advanced pancreatic cancer receiving chemotherapy. Multivariate analyses of prognostic factors for survival were performed both in overall population and in subgroups with and without DM. Results Diabetes mellitus was diagnosed in 124 patients (50%) who had less distant metastasis and more hypertension. Thirty patients received statin for hyperlipidemia. Overall survival was 13.3 versus 10.0 months with and without DM (P = 0.084), but hazard ratio of DM was 1.05 (P = 0.758) in the multivariate analysis. Subgroup analysis of diabetic patients, but not in non-diabetic patients, demonstrated use of statins (hazard ratio, 0.40; P = 0.010) as a prognostic factor, as well as distant metastasis, performance status, combination therapy with gemcitabine and S-1, and use of angiotensin-converting enzyme inhibitors or angiotensin receptor blockers. No antidiabetic medications were prognostic factors. Conclusions Neither DM nor antidiabetic treatment had prognostic impact on advanced pancreatic cancer. Statin use was associated with better survival in the diabetic patients.

Predictive factors of solid food intake in patients with malignant gastric outlet obstruction receiving self‐expandable metallic stents for palliation

Aim:  As for self‐expandable metallic stents (SEMS) for malignant gastric outlet obstruction (GOO), some predictive factors of stent patency have been reported, although re‐canalization of GOO by SEMS does not necessarily lead to favorable food intake. Therefore, we analyzed the predictive factors of oral food intake following SEMS placement.

Impact of S-1 on the survival of patients with advanced pancreatic cancer.

Objective: The aim of this study was to investigate the effect of S-1 on the prognosis of advanced pancreatic cancer. Methods: In total, 112 patients with pancreatic cancer who received chemotherapy between April 2001 and April 2007 were divided into 2 groups: PreS-1 (53 patients who started chemotherapy before January 2005) and PostS-1 (59 patients who started chemotherapy after February 2005, the time of S-1 introduction). Patient characteristics and clinical outcomes were compared, and prognostic factors were analyzed. Results: Patient characteristics did not significantly differ between the 2 groups. S-1 was administered as a second-line monotherapy in 5.7% of the PreS-1 group and combined with gemcitabine as a first-line therapy in 27.1% or as second-line monotherapy in 23.7% in the PostS-1 group. Both progression-free survival and overall survival improved after introduction of S-1 (median progression-free survival, 4.4 and 5.3 months; P = 0.043; median overall survival, 9.5 and 13.1 months; P = 0.048 in PreS-1 and PostS-1 groups, respectively). Multivariate analysis revealed that the PostS-1 group (hazards ratio, 0.52; P = 0.003), performance status, and carcinoembryonic antigen were significant prognostic factors for survival. Conclusions: Introduction of S-1 may improve the prognosis of Japanese patients with advanced pancreatic cancer.

Short- and long-term outcomes of endoscopic papillary large balloon dilation with or without sphincterotomy for removal of large bile duct stones.

Abstract Objective. Removal of large bile duct stones by endoscopic papillary large balloon dilation (EPLBD) with endoscopic sphincterotomy (EST) has been proven safe and effective. Little evidence supports the benefits of a preceding EST in reducing complications. Recent studies suggest that large bile duct stone removal by EPLBD alone may be safe and effective. Material and methods. We removed large bile duct stones by EPLBD with EST from March 2008 to February 2010 and without EST from March 2010 to October 2011. Efficacy and safety of EPLBD with or without EST and late biliary complication outcomes were assessed. Results. Forty-two patients (men/women, 27/15; mean age, 76 years) underwent EPLBD: 14 underwent EPLBD with EST and 28 underwent EPLBD without EST. The mean stone size was 14 mm (9–30 mm). Overall complete stone removal rate was 98%, with 83% achieved in 1 session. Complete duct clearance by EPLBD alone was achieved in 79%. Mechanical lithotripsy was required in 4 (10%) patients. Extracorporeal shock wave lithotripsy and electrohydraulic lithotripsy were required in 4 (10%) and 1 (2%) patients, respectively. Pancreatitis and perforation occurred in 2 (5%) and 1 (2%) patients, respectively. Patients treated by EPLBD with EST and by EPLBD alone did not differ in complication outcomes. Six (14%) patients had recurrent bile duct stones, with a significant correlation to dilated common bile duct (p = 0.0351). Conclusions. EPLBD is safe and effective in patients with large bile duct stones. Preceding EST may be unnecessary.

High single-session success rate of endoscopic bilateral stent-in-stent placement with modified large cell Niti-S stents for malignant hilar biliary obstruction

Endoscopic bilateral self‐expandable metallic stent (SEMS) placement in a stent‐in‐stent method for malignant hilar biliary obstruction is technically challenging. Technical difficulties in the initial placement and reinterventions for stent occlusion are disadvantages inherent to this stent‐in‐stent method. We previously reported the feasibility of Niti‐S large cell D‐type biliary stents (LCD). This multicenter prospective consecutive study evaluated the efficacy of bilateral SEMS placement using modified LCD with large and uniform cells, a slimmer delivery system and high radial force.