Nasobiliary Drainage

Placement of nasobiliary tubes has now become a widely accepted method for therapeutic drainage and instillation of solvents into the biliary tree. The author routinely uses a 300 cm long, 7 or 10 French, specially performed Teflon catheter, which adapts to the anatomy of the duodenum and bile ducts, for the following indications: decompression of obstructed bile duct in acute suppurative cholangitis; prevention of stone impaction after endoscopic sphincterotomy; sequential cholangiography; biliary fistula; instillation of solvents for common bile duct scones; local radiotherapy of biliary malignancies; aspiration of bile for chemical and bacteriological studies; and drainage of pancreatic pseudocysts. Pancreatic or biliary drains should supplement traditional diagnostic and therapeutic modalities in patients with surgical or medical lesions of the pancreas and biliary tree

Treatment of post-cholecystectomy biliary strictures with fully-covered self-expanding metal stents - results after 5 years of follow-up

BACKGROUND: Endoscopic treatment of post-cholecystectomy biliary strictures (PCBS) with multiple plastic biliary stents placed sequentially is a minimally invasive alternative to surgery but requires multiple interventions. Temporary placement of a single fully-covered self-expanding metal stent (FCSEMS) may offer safe and effective treatment with fewer re-interventions. Long-term effectiveness of treatment with FCSEMS to obtain PCBS resolution has not yet been studied. METHODS: In this prospective multi-national study in patients with symptomatic benign biliary strictures (N = 187) due to various etiologies received a FCSEMS with scheduled removal at 6-12 months and were followed for 5 years. We report here long-term outcomes of the subgroup of patients with PCBS (N = 18). Kaplan Meier analyses assessed long-term freedom from re-stenting. Adverse events were documented. RESULTS: Endoscopic removal of the FCSEMS was achieved in 83.3% (15/18) of patients after median indwell of 10.9 (range 0.9-13.8) months. In the remaining 3 patients (16.7%), the FCSEMS spontaneously migrated and passed without complications. At the end of FCSEMS indwell, 72% (13/18) of patients had stricture resolution. At 5 years after FCSEMS removal, 84.6% (95% CI 65.0-100.0%) of patients who had stricture resolution at FCSEMS removal remained stent-free. In addition, at 75 months after FCSEMS placement, the probability of remaining stent-free was 61.1% (95% CI 38.6-83.6%) for all patients. Stent or removal related serious adverse events occurred in 38.9% (7/18) all resolved without sequalae. CONCLUSIONS: In patients with symptomatic PCBS, temporary placement of a single FCSEMS intended for 10-12 months indwell is associated with long-term stricture resolution up to 5 years. Temporary placement of a single FCSEMS may be considered for patients with PCBS not involving the main hepatic confluence. TRIAL REGISTRATION NUMBERS: NCT01014390; CTRI/2012/12/003166; Registered 17 November 2009

Nasobiliary Drainage

Placement of nasobiliary tubes has now become a widely accepted method for therapeutic drainage and instillation of solvents into the biliary tree. The author routinely uses a 300 cm long, 7 or 10 French, specially performed Teflon catheter, which adapts to the anatomy of the duodenum and bile ducts, for the following indications: decompression of obstructed bile duct in acute suppurative cholangitis; prevention of stone impaction after endoscopic sphincterotomy; sequential cholangiography; biliary fistula; instillation of solvents for common bile duct scones; local radiotherapy of biliary malignancies; aspiration of bile for chemical and bacteriological studies; and drainage of pancreatic pseudocysts. Pancreatic or biliary drains should supplement traditional diagnostic and therapeutic modalities in patients with surgical or medical lesions of the pancreas and biliary tree

Injection Therapy for Nonvariceal Gastrointestinal Bleeding

Gastrointestinal hemorrhage is a common and serious problem - its average mortality of 10% has changed little over the past 40 years. In 80% of patients the bleeding stops spontaneously. In patients with continuous or recurrent bleeding (20%), mortality and morbidity are high, and emergency surgery is often required, which has a higher mortality than the same operation performed electively. Successful therapeutic endoscopic intervention in this high risk group is necessary to improve outcome. For injection treatment of nonvariceal bleeding lesions, the author has been using the Soehendra method (1:10,000 adrenaline and polidocanol) with success in 90% of actively bleeding patients. Three controlled trials of endoscopic sclerosis in bleeding peptic ulcer disease showed decreased blood transfusions, surgery and hospital stay, but did not find any significant difference in mortality. The ideal solution and the usefulness of additional therapy are questions which must be addressed via prospective controlled trials of a large number of patients

Nonsurgical management of an impacted mechanical lithotriptor with fractured traction wires: Endoscopic intracorporeal electrohydraulic shock wave lithotripsy followed by extra-endoscopic mechanical lithotripsy

In a patient with a mid-common bile duct stone, the traction wires of a mechanical lithotriptor snapped, resulting in lithotriptor basket impaction. Simultaneous occurrence of these two potential complications of endoscopic stone extraction is very rarely reported. Extracorporeal shock wave lithotripsy failed to fragment the stone entrapped within the impacted basket. Endoscopic intracorporeal electrohydraulic shock wave lithotripsy successfully fragmented the stone under direct visualization through a cholangioscope. The entrapped stone within the basket could subsequently be pulled into the supra-ampullary bile duct for the final fragmentation with an extra-endoscopic mechanical lithotriptor cable. The present report is the first to describe a safe and effective use of endoscopic intracorporeal electrohydraulic shock wave lithotripsy followed by extra-endoscopic mechanical lithotripsy in the management of an impacted lithotriptor basket

Wire-guided cannulation versus contrast-guided cannulation in pediatric endoscopic retrograde cholangiopancreatography

Background/Aim: Wire-guided cannulation (WGC) of the common bile duct may be associated with fewer complications and higher success rate compared with contrast-guided cannulation (CGC) in adults. Data in children are lacking. The aim of this study was to compare the successful cannulation and complication rate of WGC and CGC in pediatric endoscopic retrograde cholangiopancreatography (ERCP). Patients and Methods: We report a retrospective cohort study comparing WGC to CGC in a pediatric cohort. We reviewed the medical records of 167 children who underwent ERCP over a 10-year time period (CGC, 1999-2003, WGC, 2003-2009). Indications, findings, and success were analyzed. Results: A total of 93 patients (56%) underwent WGC and 74 (44%) CGC. Children in the WGC group were younger (9.5 ± 4.7 vs. 11.5 ± 4.6 years in CGC; P = 0.006) and underwent more therapeutic ERCP interventions (70% vs. 40% in CGC), whereas diagnostic ERCP was more common in the CGC group (60%; P < 0.005). The overall success (96%) and complication rate (8%) were identical in both groups but a trend toward a reduction in the complication rate over time was noted in the WGC group. Post-ERCP pancreatitis (PEP) was documented in one patient in the WGC group (1.1%) and three patients (4.2%) in the CGC group (P-NS). Conclusion: The success and complication rate in both CGC and WGC are comparable in children but considering the patient and procedure complexity and the trend toward lower PEP in the WGC group, WGC may be the preferable cannulation technique for ERCP in children

Observation of the symmetry of core states of a single Fe impurity in GaAs

\u3cp\u3eWe report the direct observation of two mid-gap core d states of differing symmetry for a single Fe atom embedded in GaAs. These states are distinguished by the strength of their hybridization with the surrounding host electronic structure. The midgap state of Fe that does not hybridize via σ bonding is strongly localized to the Fe atom, whereas the other, which does, is extended and comparable in size to other acceptor states. Tight-binding calculations of these midgap states agree with the spatial structure of the measured wave functions and illustrate that such measurements can determine the degree of hybridization via π bonding of impurity d states. These single-dopant midgap states with strong d character, which are intrinsically spin-orbit-entangled, provide an opportunity for probing and manipulating local magnetism and may be of use for high-speed electrical control of single spins.\u3c/p\u3

Spatially resolved electronic structure of an isovalent nitrogen center in GaAs

Small numbers of nitrogen dopants dramatically modify the electronic properties of GaAs, generating spatially localized resonant states within the conduction band, pair and cluster states in the band gap, and very large shifts in the conduction-band energies with nonlinear concentration dependence. Cross-sectional scanning tunneling microscopy provides the local electronic structure of single nitrogen dopants at the (110) GaAs surface, yielding highly anisotropic spatial shapes when the empty states are imaged. Measurements of the resonant states relative to the GaAs surface states and their spatial extent allow an unambiguous assignment of specific features to nitrogen atoms at different depths below the cleaved (110) surface. Multiband tight-binding calculations around the resonance energy of nitrogen in the conduction band match the imaged features, verifying that the Green's function method can accurately describe the isolated isovalent nitrogen impurity. The spatial anisotropy is attributed to the tetrahedral symmetry of the bulk lattice and will lead to a directional dependence for the interaction of nitrogen atoms. Additionally, the voltage dependence of the electronic contrast for two features in the filled state imaging suggests these features could be related to a locally modified surface state