Management of traction wire fracture complicating mechanical basket lithotripsy

BACKGROUND AND STUDY AIMS: The application of basket catheters has become the main method of removing calculi from the biliary and pancreatic duct. However, larger or impacted stones have to be crushed and fragmented by mechanical lithotriptors before removal is possible. Sometimes, fracture of the traction wire occurs as a severe and fraught complication. We describe a precautionary measure which helps to manage this complication. PATIENTS AND METHODS: In a series of 569 consecutive patients suffering from bile or pancreatic duct stones we found 60 (10.5%) who required mechanical lithotripsy for oversized or impacted calculi. Mechanical lithotripsy was always performed initially with a long metal sheath (80 cm) in combination with a standard traction wire. If the traction wire fractured we replaced the long metal sheath stepwise by shorter ones (70cm, 60cm and 50 cm, respectively), allowing immediate continuation of the lithotriptic procedure using the same traction wire. RESULTS: During the lithotriptic procedure three of our patients (5%) were afflicted by traction wire fracture. Two patients could be relieved directly by changing the initial metal sheath to shorter ones. Because of the exceptional hardness of a pancreatic duct stone the third patient needed stone fragmentation by extracorporeal shock wave lithrotripsy (ESWL) before complete mechanical clearance of the duct could be accomplished. CONCLUSION: We advocate the initial use of a long metal sheath (80cm) to perform mechanical lithotripsy. In case of traction wire fracture the use of a shorter metal sheath allows immediate successful continuation of the procedure, thereby frequently avoiding procedures such as ESWL or surgery.     

Study of sialated neoglycoconjugates by surface enhanced Raman scattering spectroscopy

Neoglycoconjugates based on polyacrylamide and sialic acid with N-acetylneuraminic acid or sialooligosaccharides as side chains were studied by surface-enhanced Raman scattering (SERS) spectroscopy. It had previously been found that these polymers can effectively inhibit influenza virus adhesion. This study revealed the possibility to evaluate, based on the intensity of SERS signals, the overall availability for interaction and the conformational freedom of sialic acid residues in glycoconjugates. The dependence of these two factors on the structure and density of sialylated side chains was studied. The uniformity of distribution of sialylated side chains in conjugates was shown. Comparison of the results of the SERS spectroscopic study of the conjugates and the data on their inhibitory effect on the adhesion of specific strains of influenza virus allowed the identification of the conjugates for which the availability and conformational freedom of sialic acid are the main factors determining their inhibitory properties. A conclusion was also reached about the predominance of one of the mechanisms (competitive inhibition or steric stabilization) in the inhibitory properties of the specific conjugates.