Two salvage techniques using a large dilation balloon: Endoscopic recovery of a migrated biliary metal stent and endoscope passage through a difficult duodenal stricture in combination with a duodenal stent.

There have been several reports of endoscopic removal of biliary metal stents using forceps or stent-in-stent techniques. Nishikawa and colleagues describe the endoscopic recovery of a proximally migrated biliary metal stent using a large dilation balloon and endoscope passage through a difficult duodenal stricture in combination with a duodenal stent.

Endoscopic selective biliary stenting and reintervention using metal stents with a slim delivery system in a patient with complexly altered digestive anatomy.

Nishikawa and colleagues describe a case of endoscopic multiple stenting for malignant biliary stenosis in a patient with complexly altered digestive anatomy following hepaticojejunostomy with Roux-en-Y anastomosis and gastrojejunostomy with Braun enterostomy. Furthermore, reintervention for malignant stenosis extending from the intrahepatic bile duct to the intestinal tract was successfully completed.

Printed Strain Sensor with High Sensitivity and Wide Working Range Using a Novel Brittle-Stretchable Conductive Network.

There are few reports on resistive strain sensors that exhibit both high sensitivity and a wide working range under stretching. We have newly developed a high-performance strain sensor based on a brittle-stretchable conductive network that consists of both brittle and stretchable conductive layers and is fabricated on a stretchable substrate using the screen-printing method. Adding strain usually generates structural cracks in brittle conductive layers leading to a significant increase in resistance, while a stretchable conductive layer bridges these cracks to maintain the conductive pathways under high-strain conditions. This novel conductive network endows superior electrical-mechanical performance to the strain sensors, which possess high sensitivity (gauge factor > 870) over the entire working range (∼100%). Additionally, the developed sensors showed unique anisotropic bend-sensing characteristics, which could be used to detect the bending directions. This high degree of comprehensive performance results in a strain sensor with the capability for full-range human motion detection and robotic motion sensing.

Fully Printed PEDOT:PSS-based Temperature Sensor with High Humidity Stability for Wireless Healthcare Monitoring.

Facile fabrication and high ambient stability are strongly desired for the practical application of temperautre sensor in real-time wearable healthcare. Herein, a fully printed flexible temperature sensor based on cross-linked poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate) (PEDOT:PSS) was developed. By introducing the crosslinker of (3-glycidyloxypropyl)trimethoxysilane (GOPS) and the fluorinated polymer passivation (CYTOP), significant enhancements in humidity stability and temperature sensitivity of PEDOT:PSS based film were achieved. The prepared sensor exhibited excellent stability in environmental humidity ranged from 30% RH to 80% RH, and high sensitivity of -0.77% °C-1 for temperature sensing between 25 °C and 50 °C. Moreover, a wireless temperature sensing platform was obtained by integrating the printed sensor to a printed flexible hybrid circuit, which performed a stable real-time healthcare monitoring.

Transpancreatic precut papillotomy versus double-guidewire technique in difficult biliary cannulation: prospective randomized study.

BACKGROUND AND STUDY AIMS: Difficult biliary cannulation and unintentional pancreatic duct cannulation are thought to be important contributors to pancreatitis occurring after endoscopic retrograde cholangiopancreatography. Our aim was to compare and evaluate the rates of success and complications of transpancreatic precut papillotomy (TPPP) and the double-guidewire technique (DGT), both with prophylactic pancreatic stenting. PATIENTS AND METHODS: From April 2011 to March 2014, patients with difficult biliary cannulation, in whom we planned to first position a guidewire in the pancreatic duct, were enrolled, and 68 patients were prospectively randomly allocated to two groups (TPPP 34, DGT 34). We evaluated the rates of success and complications for each group. RESULTS: TPPP had a significantly higher success rate (94.1 %) than DGT (58.8 %). The rate of post-ERCP pancreatitis was 2.9 % in both groups. There was no significant difference between the two groups in the overall rate of complications related to cannulation. CONCLUSION : If biliary cannulation cannot be achieved, TPPP should be selected first after unintentional pancreatic duct cannulation.

Difference in gating and doping effects on the band gap in bilayer graphene.

A band gap is opened in bilayer graphene (BLG) by applying an electric field perpendicular to the layer, which offers versatility and controllability in graphene-based electronics. The presence of the band gap has been confirmed using double-gated BLG devices in which positive and negative gate voltages are applied to each side of BLG. An alternative method to induce the electric field is electron and hole doping of each side of BLG using electron-transfer adsorbates. However, the generation of the band gap by carrier doping is still under investigation. Here, we determined whether the electron/hole doping can produce the electric field required to open the band gap by measuring the temperature dependence of conductivity for BLG placed between electron-donor self-assembled monolayers (SAMs) and electron-acceptor molecules. We found that some devices exhibited a band gap and others did not. The potentially irregular and variable structure of SAMs may affect the configuration of the electric field, yielding variable electronic properties. This study demonstrates the essential differences between gating and doping.

Clinical utility of 0.025-inch guidewire VisiGlide2TM in the endoscopic retrograde cholangiopancreatography-related procedures.

AIM: To examine the result of the use of 0.025-inch guidewire (GW) VisiGlide2TM as the first choice in the endoscopic retrograde cholangiopancreatography (ERCP)-related procedures without selecting the patient in a multicenter prospective study. METHODS: ERCP using 0.025-inch GW VisiGlide2TM as the first choice was conducted in patients who have needed ERCP, and its accomplishment rate of procedure, procedural time, incidence of accidental symptoms were compared with those of ERCP using 0.025-inch GW VisiGlideTM. RESULTS: The accomplishment rate of procedure was 97.5% (197/202), and procedural time was 23.930 ± 16.207 min. The accomplishment rate of procedure using 0.025-inch GW VisiGlideTM was 92.3% (183/195), and procedural time was 31.285 ± 19.122 min, thus the accomplishment rate of procedure was significantly improved and procedural time was significantly shortened (P < 0.05). Accidental symptoms by ERCP-related procedures were observed in 3.0% (6/202), and all were conservatively alleviated. CONCLUSION: When 0.025-inch GW VisiGlide2TM was used for ERCP-related procedure as the first choice, it showed high accomplishment rate of procedure and low incidence of accidental symptoms, suggesting it can be used as the universal GW. Clinical Trial Registry (UMIN0000016042).

Endoscopic management of unresectable malignant gastroduodenal obstruction with a nitinol uncovered metal stent: A prospective Japanese multicenter study.

AIM: To determine the safety and efficacy of endoscopic duodenal stent placement in patients with malignant gastric outlet obstruction. METHODS: This prospective, observational, multicenter study included 39 consecutive patients with malignant gastric outlet obstruction. All patients underwent endoscopic placement of a nitinol, uncovered, self-expandable metal stent. The primary outcome was clinical success at 2 wk after stent placement that was defined as improvement in the Gastric Outlet Obstruction Scoring System score relative to the baseline. RESULTS: Technical success was achieved in all duodenal stent procedures. Procedure-related complications occurred in 4 patients (10.3%) in the form of mild pneumonitis. No other morbidities or mortalities were observed. The clinical success rate was 92.3%. The mean survival period after stent placement was 103 d. The mean period of stent patency was 149 d and the patency remained acceptable for the survival period. Stent dysfunction occurred in 3 patients (7.7%) on account of tumor growth. CONCLUSION: Endoscopic management using duodenal stents for patients with incurable malignant gastric outlet obstruction is safe and improved patients' quality of life.

New tapered metallic stent for unresectable malignant hilar bile duct obstruction.

AIM: To examine the usefulness of a new tapered metallic stent (MS) in patients with unresectable malignant hilar bile duct obstruction. METHODS: This new tapered MS was placed in 11 patients with Bismuth II or severer unresectable malignant hilar bile duct obstruction, as a prospective study. The subjects were six patients with bile duct carcinoma, three with gallbladder cancer, and two with metastatic bile duct obstruction. Stenosis morphology was Bismuth II: 7, IIIa: 3, and IV: 1. UMIN Clinical Trial Registry (UMIN000004758). RESULTS: MS placement was 100% (11/11) successful. There were no procedural accidents. The mean patency period was 208.401 d, the median survival period was 142.000 d, and the mean survival period was 193.273 d. Occlusion rate was 36.4% (4/11); the causes of occlusion were ingrowth and overgrowth in 2 patients each, 18.2%, respectively. Patients with occlusion underwent endoscopic treatment one more time and all were treatable. CONCLUSION: The tapered MS proved useful in patients with unresectable malignant hilar bile duct obstruction because it provided a long patency period, enabled re-treatment by re-intervention, and no procedural accidents occurred.

Endoscopic papillary large balloon dilation for bile duct stones in elderly patients.

AIM: To investigate whether endoscopic papillary large balloon dilation (EPLBD) can be safety and effectively performed in patients aged ≥ 80 years. METHODS: Lithotomy by EPLBD was conducted in 106 patients with bile duct stones ≥ 13 mm in size or with three or more bile duct stones ≥ 10 mm. The patients were divided into group A (< 80 years) and group B (≥ 80 years). Procedure success rate, number of endoscopic retrograde cholangiopancreatographies (ERCP), and incidence of complications were examined in both groups. RESULTS: Group B tended to include significantly more patients with peripapillary diverticulum, hypertension, hyperlipemia, cerebrovascular disease/dementia, respiratory disease/cardiac disease, and patients administered an anticoagulant or antiplatelet agent (P < 0.05). The success rate of the initial lithotomy was 88.7 (94/106)%. The final lithotomy rate was 100 (106/106)%. Complications due to treatment procedure occurred in 4.72 (5/106)% of the patients. There was no significant difference in procedure success rate, number of ERCP, or incidence of complications between group A and group B. CONCLUSION: EPLBD can be safely performed in elderly patients, the same as in younger patients.

Efficacy of stone density on noncontrast computed tomography in predicting the outcome of extracorporeal shock wave lithotripsy for patients with pancreatic stones.

OBJECTIVES: Patients with chronic pancreatitis are managed by extracorporeal shock wave lithotripsy (ESWL) for pancreatic stones. Stone density on noncontrast computed tomography (NCCT) is used to predict stone composition and fragility, but no report investigating the pancreatic stone density has been documented. We aimed to assess the usefulness of pancreatic stone density on NCCT in predicting the ESWL outcome. METHODS: We evaluated 128 consecutive patients with pancreatic stones who underwent ESWL. Pancreatic stone density on NCCT was measured in Hounsfield units. Patients with complete stone removal were compared with those with incomplete stone removal. Patient characteristics; imaging findings, including stone density; and interventions were evaluated as potential predictors. The optimal cutoff value of variables to differentiate complete removal from incomplete removal was determined by receiver operating characteristic analysis. RESULTS: Complete stone removal was achieved in 66 patients (51.6%). When the density threshold was set at 820.5 Hounsfield units, complete stone removal was achieved in 52 patients (78.8%) with lower-density stones. In multivariate analysis, single stone (P = 0.007) and lower-density stone (P < 0.001) revealed significant association with complete stone removal. CONCLUSIONS: The measurement of pancreatic stone density before therapy can help predict therapeutic outcomes.

Endoscopic papillary large balloon dilation for removal of bile duct stones.

AIM: To investigate the efficacy and outcomes of endoscopic papillary large balloon dilation (EPLBD) for bile duct stones in a multicenter prospective study. METHODS: Lithotomy by EPLBD was conducted in 124 patients with bile duct stones ≥ 13 mm in size or with three or more bile duct stones ≥ 10 mm. After endoscopic sphincterotomy, the papilla was dilated using balloons 12-20 mm in diameter fitting the bile duct diameter. RESULTS: The success rate of first-time lithotomy was 86.3% (107/124) and the final lithotomy success rate was 100% (124/124). Lithotripsy was needed in 10 of the 124 (13.6%) patients. Adverse events due to the treatment procedure occurred in 6 (4.8%) patients, all of which were mild. Performing large balloon dilation after endoscopic sphincterotomy in patients with large stones or multiple stones in the bile duct is considered to ensure the safety of treatment and to reduce the need for lithotripsy. CONCLUSION: It is suggested that treatment by EPLBD for large bile duct stones may be safe and useful.

Old age is associated with increased severity of complications in endoscopic biliary stone removal.

BACKGROUND AND AIM: Various techniques are required in endoscopic biliary stone removal. Because the presence of biliary stones is a benign disease, it is essential to minimize procedure-related complications. Having a sound knowledge of the risk factors can help reduce the number and severity of complications. We determined the risk factors for complications in patients undergoing endoscopic biliary stone removal. METHODS: This was a retrospective observational cohort study. We analyzed 743 consecutive patients with biliary stones who were treated with endoscopic retrograde cholangiopancreatography and identified the independent risk factors for complications. RESULTS: Complications occurred in 66 patients (8.9%). Pancreatitis occurred in 26 patients (3.5%), cholangitis in 16 (2.2%), bleeding in 12 (1.6%) and other in 12 (1.6%). Independent risk factors for overall complications were multiple biliary stones (P = 0.0480) and anti-thrombotic drugs (P = 0.0186).Independent risk factors for moderate or severe complications were old age (P = 0.0201), multiple biliary stones (P = 0.0300), anti-thrombotic drugs (P = 0.0131), and cirrhosis of the liver (P = 0.0013). The respective risk factors for pancreatitis, cholangitis, and bleeding were precut technique (P = 0.0005), endoscopic mechanical lithotripsy (P = 0.0421), and both anti-thrombotic drugs (P = 0.0228) and cirrhosis of the liver (P = 0.0115). CONCLUSIONS: Old age was associated with a similar complication rate to younger age but increased the severity of complications following endoscopic biliary stone removal. Improved awareness of the severity of complications may be of benefit during periprocedural management. Further studies are warranted.

Ten-year long-term results after non-surgical management of hepatolithiasis, including cases with choledochoenterostomy.

BACKGROUND: Long-term follow-up of non-surgical procedures for the management of hepatolithiasis has been reported, but risk factors for mortality have not been properly evaluated. METHODS: We conducted a retrospective study of the case records of 121 patients with hepatolithiasis who underwent endoscopic retrograde cholangiopancreatography (ERCP), peroral cholangioscopy (POCS), percutaneous transhepatic cholangioscopy (PTCS), or conservative treatment at the Department of Gastroenterology of Chiba University Hospital between January 1980 and July 2011. The primary outcome measure was mortality, defined as death due to hepatolithiasis (concomitant liver failure with cholangitis and cholangiocarcinoma). RESULTS: Complete clearance of intrahepatic stones was achieved in 22 (57.8%) of 38 patients by POCS, in 12 (66.7%) of 18 patients by ERCP, and in 10 (52.6%) of 18 patients by PTCS. The remaining 46 patients were treated conservatively. The mean follow-up period was 11.4 ± 7.1 years (range, 0.6-32.8). There were 14 hepatolithiasis-related deaths (11 with cholangiocarcinoma and three from liver failure with cholangitis) during the follow-up periods. Multivariate Cox proportional hazards analysis revealed liver atrophy (P = 0.015; HR = 3.98; 95% CI, 1.30-12.20) and congenital biliary dilatation after biliary-enteric anastomosis (P = 0.036; HR = 4.57; 95% CI, 1.11-18.87) as significant risk factors for mortality. CONCLUSIONS: Analysis of the 10-year long-term results after non-surgical management of hepatolithiasis identified liver atrophy and congenital biliary dilatation as risk factors for mortality. Patients with hepatic lobe atrophy should undergo a hepatectomy, if operable.