Safety and success of precut biliary sphincterotomy： Is it linked to experience or expertise？

AIM： To determine the rates of success and complications of precut biliary sphincterotomy （PBS） based on prior experience and to compare the complication rates between PBS and standard endoscopic sphincterotomy （ES）.
METHODS： A retrospective evaluation of prospectively collected non-randomized data at an academic tertiary referral center, The study included all patients in an eight-year period who underwent PBS and ES by a single endoscopist who had no formal training in PBS. The main outcorne measures of the study were success and complications of PBS with a comparison to complications of ES.
RESULTS： A total of 2939 endoscopic retrograde chola ngiopancreatographies （ERCPs） were performed during the study period, including 818 （28%） ES and 150 （5%） PBS procedures. Selective biliary cannulation via PBS was successful at the first attempt in 75% of the patients. Cannulation was achieved in an additional 13% of the patients at a subsequent attempt （total 87%）. Complication rate from PBS was 45% higher than ES, but did not differ significantly [7% （10/50） vs 5% （38/818）, P = 0.29]. None of the complications from PBS was severe. A significant trend towards increasing success existed with regard to the endoscopist＇s first attempt at precut （P = 0.0393, Cochran-Armitage exact test for trend, Z = -1.7588）.
CONCLUSION： Despite the lack of specific training in this technique, PBS was performed with a high success rate and a complication rate similar to or less than reports from other experienced centers. These results suggest that endoscopic experience and perhaps innate endoscopic skill may play an important role in the outcome of this procedure.     

Cellular mechanisms of plasmalemmal sealing and axonal repair by polyethylene glycol and methylene blue

Mammalian neurons and all other eukaryotic cells endogenously repair traumatic injury within minutes by a Ca²⁺‐induced accumulation of vesicles that interact and fuse with each other and the plasmalemma to seal any openings. We have used uptake or exclusion of extracellular fluorescent dye to measure the ability of rat hippocampal B104 cells or rat sciatic nerves to repair (seal) transected neurites in vitro or transected axons ex vivo. We report that endogenous sealing in both preparations is enhanced by Ca²⁺‐containing solutions and is decreased by Ca²⁺‐free solutions containing antioxidants such as dithiothreitol (DTT), melatonin (MEL), methylene blue (MB), and various toxins that decrease vesicular interactions. In contrast, the fusogen polyethylene glycol (PEG) at 10–50 mM artificially seals the cut ends of B104 cells and rat sciatic axons within seconds and is not affected by Ca²⁺ or any of the substances that affect endogenous sealing. At higher concentrations, PEG decreases sealing of transected axons and disrupts the plasmalemma of intact cells. These PEG‐sealing data are consistent with the hypothesis that lower concentrations of PEG directly seal a damaged plasmalemma. We have considered these and other data to devise a protocol using a well‐specified series of solutions that vary in tonicity, Ca²⁺, MB, and PEG content. These protocols rapidly and consistently repair (PEG‐fuse) rat sciatic axons in completely cut sciatic nerves in vivo rapidly and dramatically to restore long‐lasting morphological continuity, action potential conduction, and behavioral functions. © 2012 Wiley Periodicals, Inc.