Early and long-term clinical outcomes of endoscopic interventions for benign pancreatic duct stricture/obstruction-the possibility of additional clinical effects of endoscopic ultrasonography-guided pancreatic drainage.

OBJECTIVES: For benign pancreatic duct strictures/obstructions (BPDS/O), endoscopic ultrasonography-guided pancreatic drainage (EUS-PD) is performed when endoscopic transpapillary pancreatic drainage (ETPD) fails. We clarified the clinical outcomes for patients with BPDS/O who underwent endoscopic interventions through the era where EUS-PD was available. METHODS: Forty-five patients with BPDS/O who underwent ETPD/EUS-PD were included. We retrospectively investigated overall technical and clinical success rates for endoscopic interventions, adverse events, and clinical outcomes after successful endoscopic interventions. RESULTS: The technical success rates for ETPD and EUS-PD were 77% (35/45) and 80% (8/10), respectively, and the overall technical success rate using two drainage procedures was 91% (41/45). Among the 41 patients who underwent successful endoscopic procedures, the clinical success rates were 97% for the symptomatic patients (35/36). The rates of procedure-related pancreatitis after ETPD and EUS-PD were 13% and 30%, respectively. After successful endoscopic interventions, the cumulative 3-year rate of developing recurrent symptoms/pancreatitis was calculated to be 27%, and only two patients finally needed surgery. Continuous smoking after endoscopic interventions was shown to be a risk factor for developing recurrent symptoms/pancreatitis. CONCLUSIONS: By adding EUS-PD to ETPD, the technical success rate for endoscopic interventions for BPDS/O was more than 90%, and the clinical success rate was nearly 100%. Due to the low rate of surgery after endoscopic interventions, including EUS-PD, for patients with BPDS/O, EUS-PD may contribute to their good clinical courses as a salvage treatment for refractory BPDS/O.

Value of repeated cytology for intraductal papillary mucinous neoplasms of the pancreas with high risk potential of malignancy: Is it a promising method for monitoring a malignant transformation?

OBJECTIVES: The efficacy of and indications for cytological reexamination to detect malignant changes in branch duct type intraductal papillary mucinous neoplasms (BD-IPMNs) have not been studied in detail. We conducted a retrospective study to evaluate the efficacy and indications of cytological reexamination by using pancreatic juice (repeated cytology) for BD-IPMNs. METHODS: Forty-five patients who underwent repeated cytology after a diagnosis of benignancy by using initial cytology were recruited for this study. RESULTS: Thirty-eight patients, excluding 7 patients with lack of surveillance period after the final cytology, were classified into Malignancy (n = 13) and Benignancy groups (n = 25) on the bases of the findings from resected specimens or changes in BD-IPMNs after repeated cytology. The sensitivity and specificity to detect malignant changes in BD-IPMNs by using repeated cytology were 62% and 100%, respectively. For the 12 patients with mural nodules (MNs) ≥ 5 mm (67% of them were malignant), the sensitivity was 50%, whereas, for the 26 patients without MNs ≥ 5 mm (19% of them were malignant), it was 80%. In addition, malignant changes in BD-IPMNs after initial cytology occurred in 62% of the patients with changes in the MNs and 27% of the patients with an increase in the cyst size. CONCLUSION: Repeated cytology can play a role in the determination for surgery even after a diagnosis of benignancy by using initial cytology, especially for BD-IPMNs without MNs ≥5 mm. In addition, changes in the MNs or cyst size may be appropriate indications for repeated cytology.

Japan Gastroenterological Endoscopy Society guidelines for endoscopic sphincterotomy.

The Japan Gastroenterological Endoscopy Society (JGES) has recently compiled guidelines for endoscopic sphincterotomy (EST) using evidence-based methods. Content regarding actual clinical practice, including detailed endoscopic procedures, instruments, device types and usage, has already been published by the JGES postgraduate education committee in May 2015 and, thus, in these guidelines we avoided duplicating such content as much as possible. The guidelines do not address pancreatic sphincterotomy, endoscopic papillary balloon dilation (EPBD), and endoscopic papillary large balloon dilation (EPLBD). The guidelines for EPLBD are planned to be developed separately. The evidence level in this field is often low and, in many instances, strong recommendation has to be determined on the basis of expert consensus. At this point in time, the guidelines are divided into six items including indications, techniques, specific cases, adverse events, outcomes, and postoperative follow up.

Japan Gastroenterological Endoscopy Society guidelines for endoscopic papillary large balloon dilation.

The Japan Gastroenterological Endoscopy Society has developed the 'EPLBD Clinical Practice Guidelines' as fundamental guidelines based on new scientific techniques. EPLBD is a treatment method that has recently become widely used for choledocolithiasis. The evidence level in this field is usually low, and in many instances, the recommendation grading has to be determined on the basis of expert consensus. At this point, the guidelines are divided into the following six sections according to the 'EST Clinical Practice Guidelines': (i) Indications, (ii) procedures, (iii) special cases, (iv) procedure-related adverse events, (v) treatment outcomes, and (vi) postoperative follow up observation.

Pancreatic juice cytology with immunohistochemistry to detect malignancy and histologic subtypes in patients with branch duct type intraductal papillary mucinous neoplasms of the pancreas.

BACKGROUND AND AIMS: The aim of this study was to elucidate the efficacy of pancreatic juice cytology with the cell-block method (CB-PJC) for the determination of surgery in patients with branch duct intraductal papillary mucinous neoplasm (BD-IPMN). METHODS: In 138 patients with BD-IPMN from whom pancreatic juice was collected under ERCP for CB-PJC, we retrospectively evaluated the following: (1) the rate of successfully evaluated CB-PJC; (2) the ability of CB-PJC to diagnose malignancy and to identify pathologic subtypes in resected BD-IPMNs; (3) the rate of development into invasive cancer and progression of BD-IPMNs in patients with BD-IPMNs diagnosed as benignancy by CB-PJC; and (4) post-ERCP adverse events. RESULTS: (1) The success rate of CB-PJC was 89.9%. (2) The sensitivity and specificity of CB-PJC for preoperative diagnosis of malignancy were 50% and 100%, respectively, with only hematoxylin and eosin staining, whereas they were 79% and 100%, respectively, by adding immunohistologic staining. The agreement rate of the preoperative subtypes by CB-PJC with the subtypes of resected specimens was 93%. (3) The onset of invasive cancer was not detected at all on imaging studies, whereas the progression of IPMN was detected in 14 patients. Multivariate analysis revealed the risk factor of progression to be non-gastric type. The cumulative 5-year progression rate in this group was 89%. (4) Post-ERCP pancreatitis developed in 13 patients (7.7%). CONCLUSIONS: The diagnostic efficacy of preoperative CB-PJC for malignant BD-IPMN was excellent. The results may suggest the feasibility of applying preoperative subtyping by CB-PJC for decisions as to whether surgery is indicated.

[Mixed adenoneuroendocrine carcinoma of the gallbladder diagnosed by endoscopic transpapillary catheterization using bile cytology assessed by the cell block method].

A 65-year-old woman was suspected of having advanced gallbladder cancer based on imaging results. This was considered inoperable because it was accompanied by possible liver metastasis. To confirm the diagnosis prior to chemotherapy, endoscopic transpapillary catheterization in the gallbladder (ETCG) was performed. The bile cytology was analyzed by the cell block method, which revealed mixed adenoneuroendocrine carcinoma. Based on the cytological results, extended cholecystectomy and partial hepatectomy were performed for the metastatic lesions. Bile cytology by ETCG with the cell block method was useful for deciding the therapeutic strategy in this patient with metastatic gallbladder cancer.

Clinical usefulness of double-guidewire technique for difficult biliary cannulation in endoscopic retrograde cholangiopancreatography.

BACKGROUND AND AIM: Although biliary cannulation with pancreatic guidewire placement (P-GW) is useful for difficult cases in endoscopic retrograde cholangiopancreatography (ERCP), the clinical significance of wire-guided cannulation with P-GW (double-guidewire technique: DGT) has not been clarified. The aim of the present study was to evaluate the usefulness of DGT for difficult biliary cannulation after unsuccessful biliary cannulation using a cannula/sphincterotome under guidance of injected contrast with P-GW (single-guidewire technique: SGT). METHODS: One-hundred and forty-six patients with difficult biliary cannulation who underwent SGT were included in this retrospective study. DGT was carried out if SGT was unsuccessful. Pancreatic duct (PD) stenting was attempted to prevent post-ERCP pancreatitis (PEP) in all patients. The success rate of cannulation and the risk factors for PEP were investigated. RESULTS: Biliary cannulation with SGT was achieved in 70%. DGT was carried out in 25 patients with unsuccessful SGT, biliary cannulation being successful in 72%. Of the 13 patients who underwent precut sphincterotomy, biliary cannulation was achieved in 46%. The incidence of PEP in patients who had undergone SGT, DGT, and precut sphincterotomy was 8% (12: mild, 8; moderate, 3; severe, 1), 4% (mild, 1), and 0%, respectively. PD stenting was successfully carried out in 86%. Multivariate analysis revealed unsuccessful PD stenting to be the only risk factor for PEP (OR 8.3, 95% CI 2.3-30). CONCLUSIONS: DGT may replace SGT or become the salvage procedure in cases of unsuccessful SGT as a result of its high success rate with an acceptable incidence of PEP. Failed pancreatic duct stenting in these techniques was frequently associated with PEP.

Reintervention for occluded biliary metal stent for patients with malignant distal biliary stricture.

A metal stent has a longer stent patency than a plastic stent in patients with unresectable malignant distal biliary stricture. However, treatment for stent dysfunction of a metal stent remains unresolved. A review of reported articles regarding reintervention for metal stent dysfunction showed that causes of stent dysfunction included tumor ingrowth/overgrowth, stone/sludge/food impaction, and stent migration. Cleaning of the stent is associated with an early relapse of stent dysfunction. Additional placement of a covered metal stent is expected to have a longer stent patency than that of other stents such as uncovered metal stents or plastic stents. It is recommended that occluded covered metal stents be removed if possible. Stent trimming with argon plasma coagulation is sometimes useful for the treatment of stent displacement. No strategy for occluded metal stents has been established yet. Further clinical trials regarding proper treatments are necessary.

Therapeutic endoscopic retrograde cholangiography using a single-balloon enteroscope in patients with Roux-en-Y anastomosis.

BACKGROUND: The aim of the present study was to evaluate the usefulness of a single-balloon enteroscope (SBE) including a newly developed short SBE (SIF-Y0004) for therapeutic endoscopic retrograde cholangiography (ERC) in patients with Roux-en-Y (R-Y) anastomosis. PATIENTS AND METHODS: Therapeutic ERC using a SBE was attempted in 19 cases (41 procedures) with R-Y anastomosis after gastrectomy. A standard SBE (working length of 200 cm, working channel of 2.8 mm) was used in 11 cases (Group L), and a short SBE (working length of 152 cm, working channel of 3.2 mm) was used in eight cases (Group S). RESULTS: Insertion of the scope up to the major papilla was achieved in 79% (15/19) of cases. Average insertion time was 37.0 ± 13.8 min (range, 19-62 min). Bile duct cannulation rate was 79% (11/14) after exclusion of the initial case in which scope exchange was unsuccessful. Average procedure time was78.8 ± 26.9 min (18-119 min). The scheduled therapeutic procedure was completed in 67% (10/15) of the cases (53% [10/19] on an intention-to-treat basis). Cardiorespiratory suppression due to sedative agents resulting in scope withdrawal developed in one procedure (2.4%; 1/41). Although there was no significant difference in therapeutic results between the two groups, the number of procedures was smaller (1.8 ± 1.3 vs 3.6 ± 3.1; P = 0.286) in Group S than in Group L. CONCLUSIONS: Therapeutic ERC using a SBE for patients with R-Y anastomosis is considered to be safe and effective. A short SBE appears to be promising for further improvement in therapeutic results.

Efficacy and safety of a WallFlex enteral stent for malignant gastric obstruction.

AIM: The aim of the present study was to investigate the efficacy and safety of a newly available enteral WallFlex stent for malignant gastric outlet obstruction (GOO). METHODS: Twenty-one consecutive patients with symptomatic (unable to take solids) malignant GOO treated by a WallFlex stent from April 2010 to February 2012 were included and analyzed retrospectively. Main outcome measurements were technical success, early complications, clinical response (elimination of the need for nasogastric tube drainage), clinical success (improvement of oral intake to a GOO score of 2 or 3), and duration of sustaining a GOO score of 2 or 3 after clinical success (median duration until reworsening of GOO score to <2 by the Kaplan-Meier method). A four-point GOO scoring system (0-3) was used for estimation of oral intake. RESULTS: Technical success rate was 100%. Bleeding and perforation after stent placement and stent dislocation/migration in the follow-up period did not occur in any patients, whereas one patient (5%) developed moderate post-procedural pancreatitis. Clinical response and clinical success was achieved in all patients and in 81% (17/21), respectively. In 17 patients whose GOO score had improved to 2 or 3 after stent placement, eight (47%) developed reworsening of the GOO score to <2 with a median time of 148 days (95% confidence interval [CI], 0-328; Kaplan-Meier method). Median survival time after the initial intervention was 61 days (95% CI, 40-82). CONCLUSION: Placement of an enteral WallFlex stent in patients with malignant GOO is safe and effective.

Prospective randomized controlled study comparing cell block method and conventional smear method for bile cytology.

BACKGROUND AND AIM: There is a paucity of data on the cell block (CB) method for bile cytology. We compared the diagnostic efficacy of the CB method with that of conventional smear cytology for bile obtained by endoscopic retrograde cholangiopancreatography (ERCP) in a randomized controlled trial manner. METHODS: A total of 137 patients with biliary tract lesions suspicious of malignancy who had undergone bile collection under ERCP were recruited to this study. After sampling, the bile was randomized to the CB method (n = 69) or to smear cytology (n = 68). CB sections were prepared using the sodium alginate method and subjected to hematoxylin-eosin, Alcian blue-periodic acid-Schiff stain, and immunohistochemical stains. Both Papanicolaou and Giemsa stains were used for smear cytology. RESULTS: The final diagnosis was malignancy in 94 patients: bile duct cancer, 42; pancreatic head cancer, 34; gallbladder cancer, 16; and ampullary cancer, two. The diagnostic accuracy of the CB method and that of smear cytology were 64% and 53%, respectively (P = 0.20). The sensitivity of the CB method (53%) was significantly better than that of smear cytology (28%; P = 0.014). Their respective sensitivities were 80% and 31% (P = 0.002) for bile duct cancer, 20% and 15% (P = 1.0) for pancreatic head cancer, and 30% and 67% (P = 0.30) for gallbladder cancer. CONCLUSION: The CB method for bile cytology showed a higher diagnostic yield than smear cytology. Its diagnostic sensitivity was satisfactory in cases of bile duct cancer.

Visualization of pancreatic juice movement using unenhanced MR imaging with spin labeling: preliminary results in normal and pathophysiologic conditions.

PURPOSE: To visualize the movement of pancreatic juice noninvasively by using an unenhanced magnetic resonance (MR) imaging technique. MATERIALS AND METHODS: Institutional review board approval and informed consent were obtained for this study. A flow-out technique of time-spatial labeling inversion pulse (SLIP) technique was applied using both nonselective and selective inversion pulses to label, or tag, pancreatic juice to move out of the region. Ten normal (eight men, two women; age range, 22-61 years; mean age, 35 years) and two pathologic conditions were examined on a commercially available 1.5 Tesla MR imager with quadrature-detected phased-array coils. All images were evaluated by two radiologists to assess depiction of the pancreatic juice movement or pancreatic juice reflux as compared to the pancreatic duct or the common bile duct on MRCP obtained before time-SLIP examination. RESULTS: The tagged pancreatic juice was satisfactory visualized after applying the pulse labeling. Noninvasive visualization of pancreatic juice movement, including normal pancreatic juice movement and reflux from the main pancreatic duct into the common bile duct, was possible by using the unenhanced time-SLIP technique. CONCLUSION: Noninvasive visualization of pancreatic juice movement is possible by using the unenhanced MR imaging time-SLIP technique.

Endoscopic treatment for biliary stricture secondary to chronic pancreatitis.

The causes of benign biliary stricture include chronic pancreatitis, primary/immunoglobulin G4-related sclerosing cholangitis and complications of surgical procedures. Biliary stricture due to fibrosis as a result of inflammation is sometimes encountered in patients with chronic pancreatitis. Frey's procedure, which can provide pancreatic duct drainage with decompression of biliary stricture, can be an initial treatment for chronic pancreatitis with pancreatic and bile duct strictures with upstream dilation. When patients are high-risk surgical candidates or hesitate to undergo surgery, endoscopic treatment appears to be a potential second-line therapy. Placement of multiple plastic stents is currently considered to be the best choice as endoscopic treatment for biliary stricture due to chronic pancreatitis. Temporary placement with a fully covered metal stent has become an attractive option due to the lesser number of endoscopic retrograde cholangiopancreatography (ERCP) sessions and its large diameter. Further clinical trials comparing multiple placement of plastic stents with placement of a covered metal stent for biliary stricture secondary to chronic pancreatitis are awaited.

Metallic stent deployment in endosonography-guided biliary drainage: long-term follow-up results in patients with bilio-enteric anastomosis.

BACKGROUND AND AIM: Although reports on endosonography-guided biliary drainage (ESBD) have been increasing, only a few reports on deployment of a self-expandable metal stents (SEMS) have been reported. The aim of the present study was to evaluate the safety and efficacy of SEMS deployment in ESBD. METHODS: Of 42 patients who underwent ESBD during the period from January 2007 to August 2011, 21 patients with unresectable malignant biliary obstruction in whom SEMS deployment had been attempted were included. In the first session, a plastic stent or SEMS was placed in a bilio-enteric anastomosis (BEA) method. SEMS was deployed with the one-step technique or with replacement of a plastic stent with a SEMS in the second session. The technical success, early and late complications, and stent patency of SEMS were evaluated. RESULTS: One-step SEMS deployment was attempted in seven patients, and SEMS was deployed with stent exchange in 14. SEMS deployment was successful in all patients without any complications. Finally, SEMS was placed in a BEA method in 16 patients (extrahepatic bile duct, 13; intrahepatic bile duct, three), and with antegrade deployment in five. Late complications occurred in three patients who underwent deployment of SEMS in a BEA method (stent obstruction in two and reflux cholangitis in one). The mean stent patency period was 433 days. CONCLUSIONS: As SEMS deployment in ESBD is safe and provides long stent patency, a SEMS seems to be the stent of choice in ESBD for patients with unresectable malignant biliary obstruction in whom long survival is expected.

Impact of technical modification of endoscopic papillectomy for ampullary neoplasm on the occurrence of complications.

AIM: To evaluate the usefulness of a modified technique of endoscopic papillectomy (EP) for lessening the occurrence of complications. METHODS: Indications for EP were adenoma or well-differentiated adenocarcinoma confined to the papilla of Vater (T1) without tumor spread into the bile/pancreatic duct. Sixteen patients underwent the modified technique, which consists of resection with the Endocut mode, followed by biliary/pancreatic sphincterotomy and stenting (Group A). Twelve patients who had undergone EP, using a cutting current, followed by pancreatic duct stenting were included as control (Group B). The frequency of complications and clinical outcomes were retrospectively compared between the two groups. RESULTS: Sixteen patients had adenoma, and 12 had adenocarcinoma. Early complications occurred in 36% of all patients (hemorrhage, 7; cholangitis, 3; perforation, 2; cholecystitis, 1). The frequency of early complications in Group A was significantly lower than that in Group B (6% vs 75%, odds ratio [OR] 0.022, 95% confidence interval [CI], 0.0020-0.25). Late complications occurred in 18% of the patients (bile duct stone, 3; hemorrhage, 1; pancreatitis, 1). There was no significant difference in the late complication rate between Group A and Group B (19% vs 17%). Local recurrences were found in 14% of the patients, without a significant difference between Group A and Group B (19% vs 8%) during a mean follow-up period. All recurrent tumors were successfully treated with argon plasma coagulation. CONCLUSIONS: The modified technique of EP for ampullary neoplasm contributed to lessening the occurrence of early complications. However, further refinement of this technique is necessary for improving the clinical outcome.

Prospective randomized controlled study comparing cell block method and conventional smear method for pancreatic juice cytology.

AIM: To elucidate the diagnostic efficacy of the cell block (CB) method by comparing it with that of conventional smear cytology for pancreatic juice obtained by endoscopic retrograde cholangiopancreatography (ERCP) in a randomized controlled trial fashion. METHODS: A total of 170 patients with pancreatic lesions suspicious of being malignant who underwent pancreatic juice collection without giving secretin under ERCP were enrolled in this study. After sampling, the pancreatic juice was randomized to the CB method (n = 85) or to smear cytology (n = 85). CB sections were subjected to hematoxylin-eosin, periodic acid Schiff-Alcian blue, and immunohistochemical stains. Both Papanicolaou stain and Giemsa stain were used for smear cytology. RESULTS: The final diagnosis was malignancy in 54 patients: pancreatic cancer, 45; intraductal papillary-mucinous carcinoma, six; and endocrine tumor, three. The number of patients with a cytological borderline malignancy in the CB group (3.5%) was significantly smaller than that in the smear group (27.1%) (P < 0.001). The diagnostic accuracy of the CB method and that of smear cytology were 76.5% (65/85) and 74.1% (63/85), respectively (P = 0.72), and their respective sensitivities were 50% (14/28) and 38.5% (10/26) (P = 0.39). The sensitivity of the CB method (88.9%) was better than that of smear cytology (42.9%) for invasive ductal carcinoma in the pancreas head (P = 0.048). CONCLUSIONS: The CB method using immunostaining for pancreatic juice cytology showed a much lower rate of equivocal borderline malignancy and a tendency for a higher diagnostic yield compared with smear cytology. Its diagnostic sensitivity, however, was not satisfactory except for pancreatic-head cancer.

Intraductal ultrasonography in the diagnosis of bile duct stones: when and whom?

BACKGROUND AND AIM: Biliary intraductal ultrasonography (IDUS) is highly sensitive in visualizing bile duct stones (BDS). Indications for IDUS, however, in cases of suspected BDS have not yet been established. The aim of the present study was to elucidate adequate indications for IDUS in cases that undergo endoscopic retrograde cholangiopancreatography (ERCP) due to suspected BDS. METHODS: A total of 213 patients who were suspected of having BDS were included in this retrospective study. The patients were divided into two groups: Group A in which BDS was visualized by ERCP; and Group B in which BDS was demonstrated only by IDUS. Comparison between the groups was carried out. RESULTS: ERCP successfully visualized BDS in 166 patients. Forty-seven patients underwent IDUS, which revealed BDS and biliary sludge in 12 and eight patients, respectively. The diameter of the largest stone was 13 ± 6 mm in Group A and 5 ± 1 mm in Group B (P < 0.001). The sensitivity, specificity, and accuracy of ERCP in the diagnosis of BDS were 93%, 100%, and 94%, respectively. The sensitivity was influenced by the size of BDS: 100% in cases of stones ≥ 8 mm in size, but 74% in those with stones < 8 mm. In cases with stones < 8 mm, the sensitivity was significantly affected by the bile duct diameter (≥ 12 mm vs < 12 mm, P < 0.05). CONCLUSION: When ERCP fails to visualize stones in patients with suspected BDS, IDUS is recommended, especially in those with a bile duct ≥ 12 mm in diameter.

Lateral spread along the main pancreatic duct in branch-duct intraductal papillary-mucinous neoplasms of the pancreas: usefulness of intraductal ultrasonography for its evaluation.

BACKGROUND: Intraductal papillary mucinous neoplasms (IPMN) of the pancreas tend to spread intraepithelially along the pancreatic duct wall. We evaluated histopathological intraductal lateral spread (LS) along the main pancreatic duct (MPD) from branch-duct IPMN and investigated the usefulness of intraductal ultrasonography (IDUS) for its preoperative diagnosis. PATIENTS AND METHODS: Twenty-four patients with branch-duct IPMN who had undergone preoperative IDUS and surgery were reviewed clinicopathologically. The prevalence and histological length of LS along the MPD from branch-duct IPMN, characteristics of the patients with LS, and efficacy of LS assessment by IDUS were examined. RESULTS: LS along the MPD was observed in 54% of the subjects. In the group of patients with LS, its mean length was 25.2±16.8mm (5-50mm) and the diameter of the MPD was 6mm or greater. Of the patients with LS, those in whom the length of LS along the MPD was longer than the diameter of the cystically dilated branch accounted for 30%. The diameter of the MPD in the group with LS was significantly greater than that in the group without LS (P=0.03). The sensitivity, specificity, and overall accuracy of IDUS in the detection of LS were 92%, 91%, and 92%, respectively. CONCLUSION: LS along the MPD was detected in about half of the resected cases of branch-duct IPMN. Preoperative transpapillary IDUS may be beneficial for the determination of the resection line, especially in those branch-duct IPMN patients in whom the MPD is 6 mm or greater in diameter.

Single-session endoscopic bilateral y-configured placement of metal stents for hilar malignant biliary obstruction.

BACKGROUND: The aim of this study was to evaluate the efficacy and safety of endoscopic bilateral biliary metal stent placement for hilar malignant obstruction. PATIENTS AND METHODS: Twenty patients with unresectable malignant hilar biliary obstruction who had undergone endoscopic bilateral Y-configured biliary drainage with metal stents were enrolled as a study group (YMS group). Thirty-seven patients who had undergone bilateral drainage with plastic stents were selected as a historical control (PS group). Two newly designed metal stents for bilateral Y-configured placement were endoscopically deployed in a partial stent-in-stent manner in one session. Technical success, early complications, and stent patency were evaluated. RESULTS: The technical success rate in the YMS group was 100%. Mild post-endoscopic retrograde cholangiopancreatography pancreatitis occurred in one patient in the YMS group and in two in the PS group. The success rate of biliary decompression was 95% in the YMS group and 89% in the PS group (P=0.65). During a median follow-up period of 7.3months, the incidence of stent occlusion in the YMS group was significantly lower than that in the PS group (30% vs 62%, P=0.028). Mean stent patency in the YMS group was 250days and that in the PS group was 115days (P=0.0061). Risk factors for stent occlusion were bile duct cancer (P=0.035) and the PS group (P=0.07) by multivariate analysis. CONCLUSION: Single-session endoscopic bilateral biliary placement of newly designed metal stents for hilar malignant obstruction is safe and useful with a high technical success rate and a long patency period.

[A case of mucinous cystadenoma of the pancreas resected after a 10-year follow-up].

A 40-year-old woman was hospitalized because of acute pancreatitis. CT showed a monolocular cyst thought to be a pseudocyst. The patient was followed as an outpatient. The size of the cyst decreased 6 years later. Ultrasonography 10 years later demonstrated an enlarged cyst with a cyst-in-cyst formation. A tendency to increase in size and the irregular wall thickening indicated that the cyst was a malignant mucinous cystic neoplasm (MCN) and distal pancreatectomy was performed. The tumor was diagnosed histologically as a mucinous cystadenoma. A case of MCN resected after long-term follow-up is extremely rare. The present case is thought to be important for elucidation of the natural history of MCNs.