Comparison of novel large-bore and conventional-bore covered self-expandable metal stents for malignant gastric outlet obstruction: Multicenter, retrospective study.

OBJECTIVES: Covered self-expandable metal stent (cSEMS) for gastric outlet obstruction (GOO) has been developed to overcome tumor ingrowth but is prone to be associated with an increased risk of migration. Clinical impact of the novel large-bore cSEMS for malignant GOO remains unclear. METHODS: A total of 117 patients undergoing endoscopic cSEMS placement for malignant GOO were enrolled in this multicenter retrospective study. Technical and clinical success, adverse events, recurrent GOO, and survival after stent placement were compared between 24 mm-cSEMS (n = 49) and 20 mm-cSEMS (n = 68). RESULTS: Patient characteristics were well-balanced and thus similar survival was observed between the two groups (136 days vs. 89 days, P = 0.60). Technical success rate of 100% and clinical success rate of 96% were achieved both in 24 mm-cSEMS and 20 mm-cSEMS, respectively. The median cumulative time to recurrent GOO was significantly longer in 24 mm-cSEMS than in 20 mm-cSEMS (380 days vs. 138 days, P = 0.01). The incidence of adverse events and recurrent GOO was comparable: 12% vs. 15% (P = 0.91), and 16% vs. 31% (P = 0.11); however, no stent migration was observed in 24 mm-cSEMS. In a subgroup analysis, the superiority of 24 mm-cSEMS to 20 mm-cSEMS was demonstrated in extrinsic cancers (380 days vs. 121 days, P = 0.01) but not in intrinsic cancers (151 days vs. not reached, P = 0.47). CONCLUSIONS: The 24 mm-cSEMS may improve time to recurrent GOO with ensuring acceptable safety in patients with malignant GOO.

Multicenter randomized trial of endoscopic papillary large balloon dilation without sphincterotomy versus endoscopic sphincterotomy for removal of bile duct stones: MARVELOUS trial.

BACKGROUND : Endoscopic papillary large balloon dilation (EPLBD) has been increasingly used for the management of large common bile duct (CBD) stones. Although EPLBD is often preceded by endoscopic sphincterotomy (EST), EPLBD alone without EST has been increasingly reported as an alternative to EST for large CBD stones. METHODS : This multicenter randomized trial was conducted at 19 Japanese institutions to compare the efficacy and safety of EPLBD alone versus EST for the removal of large (≥ 10 mm) CBD stones. The primary end point was complete stone removal in a single session. The secondary end points included: overall complete stone removal, lithotripsy use, procedure time, adverse events, and cost. RESULTS: 171 patients with large CBD stones were included in the analysis. The rate of single-session complete stone removal was significantly higher in the EPLBD-alone group than in the EST group (90.7 % vs. 78.8 %; P = 0.04). Lithotripsy use was significantly less frequent in the EPLBD group than in the EST group (30.2 % vs. 48.2 %; P = 0.02). The rates of early adverse events were comparable between the two groups: rates of overall adverse events were 9.3 % vs. 9.4 % and of pancreatitis were 4.7 % vs. 5.9 % in the EPLBD and EST groups, respectively. The procedure costs were $1442 vs. $1661 in the EPLBD and EST groups, respectively (P = 0.12). CONCLUSION : EPLBD without EST for the endoscopic treatment of large CBD stones achieved a significantly higher rate of complete stone removal in a single session compared with EST, without increasing adverse events.

Retrospective Comparative Study of Side-by-Side and Stent-in-Stent Metal Stent Placement for Hilar Malignant Biliary Obstruction.

BACKGROUND: In patients with unresectable hilar malignant biliary obstruction (MBO), bilateral metal stent placement is recommended. However, treatment selection between partially stent-in-stent (SIS) and side-by-side (SBS) methods is still controversial. STUDY: Clinical outcomes of bilateral metal stent placement by SBS and SIS methods for hilar MBO were retrospectively studied in four Japanese centers. While large-cell-type uncovered metal stents were placed above the papilla in SIS, braided-type uncovered metal stents were placed across the papilla in SBS. RESULTS: A total of 64 patients with hilar MBO (40 SIS and 24 SBS) were included in the analysis. Technical success rate was 100% in SIS and 96% in SBS. Functional success rate was 93% in SIS and 96% in SBS. Early adverse event rates were higher in SBS (46%) than in SIS (23%), though not statistically significant (P = 0.09). Post-procedure pancreatitis was exclusively observed in SBS group (29%). Recurrent biliary obstruction rates were 48% and 43%, and the median time to recurrent biliary obstruction was 169 and 205 days in SIS and SBS, respectively. CONCLUSIONS: Other than a trend to higher adverse event rates including post-procedure pancreatitis in SBS, clinical outcomes of SIS and SBS methods were comparable in patients with unresectable hilar MBO.

Antireflux covered metal stent for nonresectable distal malignant biliary obstruction: Multicenter randomized controlled trial.

BACKGROUND AND AIM: An antireflux metal stent (ARMS) for nonresectable distal malignant biliary obstruction (MBO) may prevent recurrent biliary obstruction (RBO) as a result of duodenobiliary reflux and prolong time to RBO (TRBO). Superiority of ARMS over conventional covered self-expandable metal stents (SEMS) has not been fully examined. METHODS: We conducted a multicenter randomized controlled trial to examine whether TRBO of an ARMS with a funnel-shaped valve was longer than that of a covered SEMS in SEMS-naïve patients. We enrolled 104 patients (52 patients per arm) at 11 hospitals in Japan. Secondary outcomes included causes of RBO, adverse events, and patient survival. RESULTS: TRBO did not differ significantly between the ARMS and covered SEMS groups (median, 251 vs 351 days, respectively; P = 0.11). RBO as a result of biliary sludge or food impaction was observed in 13% and 9.8% of patients who received an ARMS and covered SEMS, respectively (P = 0.83). ARMS was associated with a higher rate of stent migration compared with the covered SEMS (31% vs 12%, P = 0.038). Overall rates of adverse events were 20% and 18% in the ARMS and covered SEMS groups, respectively (P = 0.97). No significant between-group difference in patient survival was observed (P = 0.26). CONCLUSIONS: The current ARMS was not associated with longer TRBO compared with the covered SEMS. Modifications including addition of an anti-migration system are required to use the current ARMS as first-line palliative treatment of distal MBO (UMIN-CTR clinical trial registration number: UMIN000014784).

Early pancreatic stent placement in wire-guided biliary cannulation: A multicenter retrospective study.

BACKGROUND AND AIM: Guidewire insertion to a pancreatic duct under wire-guided cannulation (WGC) during endoscopic retrograde cholangiopancreatography (ERCP) is associated with a high incidence of post-ERCP pancreatitis (PEP). Pancreatic stent placement followed by WGC (PS-WGC) is considered for these cases to reduce PEP. This study was aimed to examine the effectiveness of PS-WGC compared with repeated WGC. METHODS: The consecutive data of patients without history of ERCP who underwent ERCP for biliary intervention were retrospectively collected from five centers. Patients without guidewire insertion to the pancreatic duct were excluded. Pancreatic stent was immediately placed after guidewire insertion to the pancreatic duct in the PS-WGC group. The association between the method of biliary cannulation (PS-WGC or repeated WGC) and PEP was analyzed using multivariable logistic regression model. RESULTS: A total of 590 patients (183 in the PS-WGC and 407 in the repeated WGC group) were included. PS-WGC decreased PEP (8.7% vs 19%, P = 0.001) and improved its severity (moderate and severe PEP; 2.2% vs 6.4%, P = 0.04) compared with repeated WGC. PS-WGC was associated with reduction of PEP in the multivariable model (Odds ratio 0.31, P < 0.001). The rates of difficult cannulation and overall successful biliary cannulation were not different between the two groups (66% vs 70%, P = 0.39 and 98% vs 96%, P = 0.21 in the PS-WGC and repeated WGC group, respectively). CONCLUSIONS: Pancreatic stent placement followed by WGC reduced PEP in patients with guidewire insertion to the pancreatic duct during WGC for native papilla compared with repeated WGC.

Endoscopic papillary large balloon dilation without sphincterotomy for users of antithrombotic agents: A multicenter retrospective study.

BACKGROUND AND AIM: With an aging population, an increasing number of individuals on antithrombotic agents are diagnosed with large bile duct stones. Studies have shown the effectiveness of endoscopic papillary large balloon dilation (EPLBD) for removal of large bile duct stones. EPLBD without endoscopic sphincterotomy (EST) may reduce the risk of procedure-related bleeding, but the safety of this procedure for users of antithrombotic agents remains unclear. METHODS: In this multicenter retrospective study, we included patients who underwent EPLBD without EST for bile duct stones between March 2008 and December 2017. We compared adverse events and other clinical outcomes between users and non-users of antithrombotic agents (antiplatelet agents and anticoagulants). RESULTS: We analyzed a total of 144 patients (47 users and 97 non-users of antithrombotic agents). Among the users, the agents were continued in 13% and were replaced with heparin in 62% during the periprocedural period. We did not observe clinically significant bleeding and thrombotic events irrespective of the use of antithrombotic agents. Overall rate of early adverse events did not differ between users and non-users (6.4% and 7.2%, P = 0.99). Procedural outcomes did not differ between the groups (necessity for lithotripsy, 28% vs. 29%; and complete stone removal in a single session, 72% vs. 71%, for users and non-users, respectively). CONCLUSIONS: Endoscopic papillary large balloon dilation without EST may be done without a substantial increase in procedure-related bleeding for users of antithrombotic agents. A larger study is required to refine the management strategy for those agents during the periprocedural period.

A Multicenter Open-Label Randomized Controlled Trial of Pancreatic Enzyme Replacement Therapy in Unresectable Pancreatic Cancer.

OBJECTIVE: Exocrine pancreatic insufficiency may impair the nutritional status in pancreatic cancer (PC), but the role of pancreatic enzyme replacement therapy (PERT) is not fully evaluated. Therefore, we conducted this multicenter open-label randomized controlled trial to evaluate the role of PERT in PC patients. METHODS: Patients with unresectable PC receiving chemotherapy were randomly assigned to pancrelipase and nonpancrelipase groups. Patients in the pancrelipase group took oral pancrelipase of 48,000 lipase units per meal. N-benzoyl-tryrosyl para-aminobenzoic acid (NBT-PABA) test was performed at baseline. Our primary endpoint was change in body mass index (BMI) at 8 weeks. Secondary endpoints were change in other nutritional status at 8 weeks and overall survival. RESULTS: A total of 88 patients were enrolled between May 2014 and May 2016. The NBT-PABA test was lower than the normal range in 90%. There were no significant differences in change in BMI at 8 weeks: 0.975 and 0.980 in the pancrelipase and the nonpancrelipase groups, respectively (P = 0.780). The other nutritional markers were also comparable. The median overall survival was 19.0 and 12.0 months (P = 0.070). CONCLUSIONS: In this randomized controlled trial, pancrelipase failed to improve the change in BMI at 8 weeks in PC patients receiving chemotherapy.

International study of endoscopic management of distal malignant biliary obstruction combined with duodenal obstruction.

OBJECTIVE: Endoscopic transpapillary or endoscopic ultrasound (EUS)-guided stent placement is used for nonresectable distal malignant biliary obstruction. We conducted a retrospective study to evaluate endoscopic biliary drainage in patients with duodenal obstruction. METHODS: We included consecutive patients who underwent endoscopic biliary drainage combined with a duodenal stent at 16 referral centers in four Asian countries. The primary outcome was time to recurrent biliary obstruction (TRBO). We assessed TRBO according to the sequence of biliary and duodenal obstruction (group 1/2/3, biliary obstruction first/concurrent/duodenal obstruction first, respectively) or the location of duodenal obstruction (type I/II/III, proximal to/affecting/distal to the ampulla, respectively). We also evaluated functional success and adverse events. RESULTS: We included 110 patients (group1/2/3, 67/29/14 patients; type I/II/III, 45/46/19 patients; endoscopic retrograde cholangiopancreatography [ERCP]/EUS-guided choledocoduodenostomy/EUS-guided hepaticogastrostomy, 90/10/10 patients, respectively). The median TRBO of all cases was 450 days (interquartile range, 212-666 days) and functional success was achieved in 105 cases (95%). The TRBO did not differ significantly by the timing or location of duodenal obstruction (p = .30 and .79, respectively). The TRBO of metal stents (n = 96) tended to be longer compared with plastic stents (n = 14, p = .083). Compared with ERCP, EUS-guided biliary drainage was associated with a higher rate of adverse events. CONCLUSION: Transpapillary or transmural endoscopic biliary drainage with a duodenal stent was effective, irrespective of the timing or location of duodenal obstruction. A prospective study is required considering the tradeoff of technical success rate, stent patency, and adverse events (ClinicalTrials.gov number, NCT02376907).

Multicenter study of endoscopic preoperative biliary drainage for malignant hilar biliary obstruction: E-POD hilar study.

BACKGROUND AND AIM: Endoscopic nasobiliary drainage (ENBD) is often recommended in preoperative biliary drainage (PBD) for hilar malignant biliary obstruction (MBO), but endoscopic biliary stent (EBS) is also used in the clinical practice. We conducted this large-scale multicenter study to compare ENBD and EBS in this setting. METHODS: A total of 374 cases undergoing PBD including 281 ENBD and 76 EBS for hilar MBO in 29 centers were retrospectively studied. RESULTS: Extrahepatic cholangiocarcinoma (ECC) accounted for 69.8% and Bismuth-Corlette classification was III or more in 58.8% of the study population. Endoscopic PBD was technically successful in 94.6%, and adverse event rate was 21.9%. The rate of post-endoscopic retrograde cholangiopancreatography pancreatitis was 16.0%, and non-endoscopic sphincterotomy was the only risk factor (odds ratio [OR] 2.51). Preoperative re-intervention was performed in 61.5%: planned re-interventions in 48.4% and unplanned re-interventions in 31.0%. Percutaneous transhepatic biliary drainage was placed in 6.4% at the time of surgery. The risk factors for unplanned procedures were ECC (OR 2.64) and total bilirubin ≥ 10 mg/dL (OR 2.18). In surgically resected cases, prognostic factors were ECC (hazard ratio [HR] 0.57), predraiange magnetic resonance cholangiopancreatography (HR 1.62) and unplanned re-interventions (HR 1.81). EBS was not associated with increased adverse events, unplanned re-interventions, or a poor prognosis. CONCLUSIONS: Our retrospective analysis did not demonstrate the advantage of ENBD over EBS as the initial PBD for resectable hilar MBO. Although the technical success rate of endoscopic PBD was high, its re-intervention rate was not negligible, and unplanned re-intervention was associated with a poor prognosis in resected hilar MBO.

Multicenter retrospective and comparative study of 5-minute versus 15-second endoscopic papillary balloon dilation for removal of bile duct stones.

BACKGROUND AND STUDY AIMS: Endoscopic papillary balloon dilation (EPBD) is a method of bile duct stone removal that has a better long-term outcome but a high risk of post-ERCP pancreatitis (PEP). Recent studies have suggested that 5-minute EPBD can reduce the incidence of PEP. This study aimed to examine the safety and effectiveness of longer duration EPBD compared with shorter duration EPBD (5 minutes vs. 15 seconds after disappearance of the waist of a dilation catheter). PATIENTS AND METHODS: Patients without a history of endoscopic sphincterotomy or EPBD who underwent EPBD to remove bile duct stones were selected retrospectively from five centers. The incidence of PEP, other early adverse events, and outcomes of EPBD were compared between the groups. A multivariable analysis of risk factors for PEP was performed. RESULTS: A total of 607 patients (157 and 450 in the 5-minute and 15-second EPBD groups, respectively) were included. There were no statistically significant differences between the groups in terms of the incidence of PEP (8.3 % and 8.9 % in the 5-minute and 15-second EPBD groups, respectively; P  = 0.871) and the incidence of overall early adverse events ( P  = 0.999). Although 5-minute EPBD elongated the procedure time (45 vs. 37 minutes, P  < 0.001), it increased the rate of complete stone removal during a single session ( P  < 0.001) and decreased the use of lithotripsy ( P  < 0.001). CONCLUSIONS: Compared with 15-second EPBD, 5-minute EPBD did not reduce the incidence of PEP.

A Novel Partially Covered Self-Expandable Metallic Stent with Proximal Flare in Patients with Malignant Gastric Outlet Obstruction.

BACKGROUND/AIMS: Endoscopic placement of self-expandable metal stents (SEMSs) has emerged as a palliative treatment for malignant gastric outlet obstruction (GOO). Although covered SEMSs can prevent tumor ingrowth, frequent migration of covered SEMSs may offset their advantages in preventing tumor ingrowth. METHODS: We conducted this multicenter, single-arm, retrospective study at six tertiary referral centers to evaluate the safety and efficacy of a partially covered SEMS with an uncovered large-bore flare at the proximal end as an antimigration system in 41 patients with symptomatic malignant GOO. The primary outcome was clinical success, and the secondary outcomes were technical success, stent dysfunction, adverse events, and survival after stent placement. RESULTS: The technical and clinical success rates were 100% and 95%, respectively. Stent dysfunctions occurred in 17 patients (41%), including stent migration in nine (23%), tumor ingrowth in one (2%), and tumor overgrowth in four (10%). Two patients (5%) developed adverse events: one pancreatitis and one perforation. No procedure-related death was observed. CONCLUSIONS: A novel partially covered SEMS with a large-bore flare proximal end was safe and effective for malignant GOO but failed to prevent stent migration. Further research is warranted to develop a covered SEMS with an optimal antimigration system.

Gemcitabine and S-1 versus gemcitabine and cisplatin treatment in patients with advanced biliary tract cancer: a multicenter retrospective study.

Objective This study aimed to compare the safety and efficacy of the combination therapy of gemcitabine and S-1 (GS) versus gemcitabine and cisplatin (GC) in patients with advanced biliary tract cancer (BTC). Methods In this multicenter retrospective cohort study, a total of 212 patients with advanced BTC receiving GS (n = 125) or GC (n = 87) between July 2006 and August 2015 were analyzed. The primary endpoint was overall survival (OS). The secondary endpoints were progression-free survival (PFS), objective tumor response, and safety. Results Patient characteristics were well balanced between the two groups, except for tumor size (the baseline sum of the largest diameter of the tumor: 6.3 cm in the GS group vs. 8.6 cm in the GC group, p = 0.01). Although the response rate was higher in the GS group than in the GC group (28.8% vs. 10.3%, p = 0.01), the median PFS and OS were comparable between the two groups (PFS of 5.6 vs. 7.6 months, p = 0.74; OS of 12.4 vs. 9.2 months, p = 0.20, respectively). Stomatitis and skin rash were more frequently observed in the GS group, whereas anemia, thrombocytopenia, nausea, and renal toxicity were more commonly observed in the GC group. Conclusion This study demonstrates that GS and GC are similar with regard to their safety and efficacy in patients with advanced BTC. GS could serve as an alternative treatment for advanced BTC as a first-line chemotherapy.

Antireflux Metal Stent as a First-Line Metal Stent for Distal Malignant Biliary Obstruction: A Pilot Study.

BACKGROUND/AIMS: In distal malignant biliary obstruction, an antireflux metal stent (ARMS) with a funnel-shaped valve is effective as a reintervention for metal stent occlusion caused by reflux. This study sought to evaluate the feasibility of this ARMS as a first-line metal stent. METHODS: Patients with nonresectable distal malignant biliary obstruction were identified between April and December 2014 at three Japanese tertiary centers. We retrospectively evaluated recurrent biliary obstruction and adverse events after ARMS placement. RESULTS: In total, 20 consecutive patients were included. The most common cause of biliary obstruction was pancreatic cancer (75%). Overall, recurrent biliary obstruction was observed in seven patients (35%), with a median time to recurrent biliary obstruction of 246 days (range, 11 to 246 days). Stent occlusion occurred in five patients (25%), the causes of which were sludge and food impaction in three and two patients, respectively. Stent migration occurred in two patients (10%). The rate of adverse events associated with ARMS was 25%: pancreatitis occurred in three patients, cholecystitis in one and liver abscess in one. No patients experienced nonocclusion cholangitis. CONCLUSIONS: The ARMS as a first-line biliary drainage procedure was feasible. Because the ARMS did not fully prevent stent dysfunction due to reflux, further investigation is warranted.

[Complete Response in a Patient with HER2-Positive Gastric Cancer and Multiple Lung Metastases with Trastuzumab-Containing Chemotherapy].

We report the case ofa 79-year-old Japanese woman diagnosed with human epidermal growth factor receptor 2 (HER2)-positive gastric cancer of the cardia with multiple lung metastases that showed complete response to trastuzumab-containing chemotherapy. First, we administered tegafur/gimeracil/oteracil (S-1) and cisplatin (CDDP) concurrently to the patient. Next, we switched to trastuzumab in combination with capecitabine and CDDP because gastric cancer tissue indicated HER2-positivity. Considering the patient's age and renal function, the dose of CDDP was decreased to 50% after starting the medication. Before the 2nd course of trastuzumab-containing chemotherapy, oral mucositis (Grade 3) and hand-foot syndrome (Grade 1) were observed. Therefore, a one-step dose reduction of capecitabine was necessary. After the 4th course, the primary gastric tumor was no longer visible endoscopically. After the 7th course, computed tomography (CT) showed the disappearance of all lung metastases. Accordingly, the patient was considered to be completely responsive to the medication. After the 12th course, recurrence of the tumor was not identified and at the request of the patient, the trastuzumab-containing chemotherapy was discontinued. Regular follow-up showed no evidence of recurrence 8 months after discontinuing treatment and the patient was in good condition 21 months after her initial diagnosis.

Early use of double-guidewire technique to facilitate selective bile duct cannulation: the multicenter randomized controlled EDUCATION trial.

BACKGROUND AND STUDY AIMS: There are no guidelines for the timing of conversion from a single-guidewire to a double-guidewire technique to facilitate selective bile duct cannulation and reduce post-endoscopic retrograde cholangiopancreatography pancreatitis (PEP), when using wire-guided cannulation. We investigated whether early conversion to the double-guidewire method, at first unintentional insertion of a guidewire into the pancreatic duct, facilitated selective bile duct cannulation and reduced PEP compared with repeated single-guidewire attempts. PATIENTS AND METHODS: A multicenter prospective randomized controlled trial included 274 patients with a naive papilla, undergoing endoscopic retrograde cholangiography (ERC) using wire-guided cannulation in whom there was unintentional insertion of the guidewire into the pancreatic duct. With the guidewire still in the duct, patients were randomly assigned to undergo the double-guidewire technique or repeated single-wire cannulation. Main outcomes were success rates for selective bile duct cannulation and PEP frequency. RESULTS: Success rates for selective bile duct cannulation within 10 attempts and 10 minutes were 75 % and 70 %, respectively, for the early double-guidewire (EDG) and repeated single-guidewire (RSG) cannulation groups (relative rate 1.07, 95 % confidence interval [95 %CI] 0.93 - 1.24, P = 0.42). Corresponding final selective bile duct cannulation rates were 98 % and 97 % (relative rate 1.01, 95 %CI 0.97 - 1.05, P = 1.00). PEP rates were 20 % and 17 %, respectively, for the EDG and RSG cannulation groups (relative risk 1.17, 95 %CI 0.71 - 1.94, P = 0.53). Double-guidewire cannulation was more effective in patients with malignant biliary stricture (relative rate 1.36, 95 %CI 1.05 - 1.77, P = 0.02). CONCLUSIONS: During therapeutic ERC using wire-guided cannulation, converting to a double-guidewire technique neither facilitated selective bile duct cannulation nor decreased PEP incidence compared with repeated use of a single-wire technique.

Clinical outcomes of secondary gastroduodenal self-expandable metallic stent placement by stent-in-stent technique for malignant gastric outlet obstruction.

BACKGROUND AND AIM: To evaluate the efficacy and safety of secondary gastroduodenal stent placement after first stent dysfunction for malignant gastric outlet obstruction. METHODS: We conducted a retrospective analysis to investigate the efficacy and safety of secondary stent-in-stent gastroduodenal stent placement. RESULTS: Among 260 patients who had been treated with first gastroduodenal stent placement for malignant gastric outlet obstruction, 29 patients (11.2%) were treated with secondary gastroduodenal stent placement because of first stent dysfunction. Pancreatic cancer was the major primary cancer (55.2%). A WallFlex duodenal stent was the most frequently inserted stent both as a first stent (75.9%) and as a secondary stent (62.1%). There were 22 patients (75.9%) that received gastroduodenal stents at the bending site (supraduodenal angle or infraduodenal angle). Technical and clinical success rates were 100% and 86.2%, respectively. Median eating period was 3.0 months, and median survival time was 3.5 months. As for related complications, gastrointestinal perforation, insufficient stent expansion, tumor ingrowth, tumor overgrowth, and cholangitis were experienced in 13.8% (four cases), 6.9% (two cases), 6.9% (two cases), 3.4% (one case), and 3.4% (one case), respectively. CONCLUSION: Secondary gastroduodenal stent placement might be effective for managing first stent dysfunction in malignant gastric outlet obstruction. However, gastrointestinal perforation was the major complication.

Risk factors for covered metallic stent migration in patients with distal malignant biliary obstruction due to pancreatic cancer.

BACKGROUND AND AIM: Covered metallic stents (CMSs) were developed to overcome tumor ingrowth in uncovered metallic stents (UMSs) for malignant biliary obstruction, but superiority of CMSs over UMSs is still controversial due to the high migration rate in CMS. Therefore, we conducted this retrospective analysis to clarify risk factors for stent migration, including mechanical properties of CMSs. METHODS: Patients with unresectable pancreatic cancer, receiving CMS for distal malignant biliary obstruction in five tertiary care centers, were retrospectively studied. Univariate and multivariate analyses to identify prognostic factors for early (< 6 months) stent migration were performed using a proportional hazards model with death or stent occlusion without stent migration as a competing risk. Two mechanical properties were included in the analysis: axial force, the recovery force that leads to a CMS straightening, and radial force (RF), the expansion force against the stricture. RESULTS: Among 290 patients who received CMS placement for distal malignant biliary obstruction, stent migration rate was 15.2%. CMS migrated early (< 6 months) in 10.0% and distally in 11.7%, respectively. In the multivariate analysis, significant risk factors for early stent migration were chemotherapy (subdistribution hazard ratios [SHR] 4.46, P = 0.01), CMS with low RF (SHR 2.23, P = 0.03), and duodenal invasion (SHR 2.25, P = 0.02). CONCLUSION: CMS with low RF, chemotherapy, and duodenal invasion were associated with CMS migration from our study.

Metallic stent with high axial force as a risk factor for cholecystitis in distal malignant biliary obstruction.

BACKGROUND AND AIM: Tumor involvement to the orifice of cystic duct (OCD) is a risk factor for cholecystitis after self-expandable metallic stent (SEMS) placement, but its prevention is still difficult. We conducted this multicenter analysis to clarify a type of SEMS or a method to place SEMS which would decrease the incidence of cholecystitis after SEMS placement. METHODS: The incidence of cholecystitis was studied in consecutive patients receiving SEMS for distal malignant biliary obstruction in five tertiary care centers. Multiple logistic regression analysis was performed to evaluate risk factors for cholecystitis. RESULTS: A total of 376 patients who received SEMS placement for distal malignant biliary obstruction were analyzed. Tumor involvement to OCD was diagnosed in 25.3%. Overall incidence of cholecystitis was 6.9%. Cholecystitis was observed in 8.0% of 300 patients with covered SEMS, 16.8% of 95 patients with tumor involvement to OCD, 10.8% of 234 patients with SEMS of high axial force (AF), and 12.0% of 158 patients with SEMS length ≤ 60 mm. In the multivariate analysis, tumor involvement to OCD (odds ratio [OR] 5.40, P < 0.001), SEMSs with high AF (OR 5.33, P = 0.002), and SEMS length ≤ 60 mm (OR 3.19, P = 0.010) are risk factors. Among patients with tumor involvement to OCD, the incidence of cholecystitis in SEMS with high and low AF was 25.0% and 5.0%, respectively. CONCLUSION: This study with an expanded cohort reconfirmed tumor involvement to OCD as a risk factor for cholecystitis after SEMS placement. SEMS with low AF might decrease cholecystitis.

Detection of painless pancreatitis by computed tomography in patients with post-endoscopic retrograde cholangiopancreatography hyperamylasemia.

OBJECTIVES: Post-endoscopic retrograde cholangiopancreatography (ERCP) pancreatitis is diagnosed on the basis of pancreatic pain and hyperamylasemia. However, because the diagnosis of abdominal pain is not objective, there may be some cases of painless pancreatitis among patients with post-ERCP hyperamylasemia (PEH). We reviewed the computed tomography (CT) findings of PEH cases to determine the incidence of painless pancreatitis. METHODS: Between July, 2005 and December, 2011, CT was performed in 91 patients with hyperamylasemia 18 h after ERCP. We reviewed the CT findings and graded the severity of pancreatitis according to the Balthazar grading system. Grades C, D, and E were defined as pancreatitis. RESULTS: Thirty-four patients (37%) had pancreatitis according to the CT findings. There was a significant difference in the serum amylase levels between the positive- and negative-CT finding groups (1306 ± 833 vs. 786 ± 315 IU/L, respectively; p = 0.0012). Receiver operating characteristic curve analysis showed that the amylase cut-off value for discriminating between the 2 groups was 795 IU/L (6.36 times the upper normal limit). CONCLUSIONS: Thirty-seven percent of PEH patients had painless pancreatitis. CT is useful to determine pancreatitis in patients taking analgesics, steroids, or anti-immunological drugs and those with diabetes mellitus and 18-h serum amylase levels of >6 times the normal upper limit.

Incidence of malignancies in patients with IgG4-related disease.

OBJECTIVE: It has been discussed whether IgG4-related disease (IgG4-RD), including autoimmune pancreatitis (AIP), is associated with malignancy; however, the issue has not been clarified. METHODS: We analyzed 113 patients with IgG4-RD in whom malignancy was not diagnosed at the time of IgG4-RD onset and the follow-up period was longer than six months. A total of 95 patients had AIP. The mean follow-up period was 73 months. The incidence of the observed malignancies was compared with the expected incidence in an age- and sex-matched general Japanese population based on the Vital Statistics of Japan. RESULTS: There were 15 malignancies (lung cancer in five patients, pancreatic cancer in two patients, gastric cancer in two patients, bile duct cancer in one patient, renal cancer in one patient, breast cancer in one patient, tongue cancer in one patient, malignant melanoma in one patient and acute myeloid leukemia in one patient) in 14 patients during the follow-up period. The calculated standardized incidence rate of the total malignancies was not significant, that is, 1.04 (95% CI 0.57-1.75). CONCLUSION: The incidence of total malignancies in IgG4-RD patients is similar to that observed in the general population. At present, it is reasonable to conclude that IgG4-RD is not associated with an increased incidence of total malignancies.