Experimental study on the friction effect of plastic stents for biliary stone fragmentation (with video)

Association of long-term endoscopic biliary stent placement with choledocholithiasis: a literature review

Endoscopic stone removal is currently the first-line procedure for the treatment of common bile duct stones. Advances in equipment and treatment techniques have expanded the scope of application of endoscopic treatment to include stones that have previously been difficult to remove endoscopically, such as stacked stones and large stones. For the treatment of common bile duct stones in elderly patients in particular, long-term placement of a biliary stent is increasingly being selected. Although periodic stent replacement is required, some reports have stated that biliary stenting is useful in terms of treatment-associated invasiveness and the incidence of accidental complications. To date, various opinions have been presented on whether the treatment of bile duct stones should aim for complete removal of stones or adopt the biliary stenting approach. Findings in previous reports suggest that both the approach for complete stone removal and the long-term stenting approach are associated with advantages and disadvantages. In this study, we reviewed previous reports on the significance of placing a stent and implementing careful monitoring rather than stone removal in patients with bile duct stones.

Drug-eluting fully covered self-expanding metal stent for dissolution of bile duct stones in vitro

BACKGROUND

The treatment of difficult common bile duct stones (CBDS) remains a big challenge around the world. Biliary stenting is a widely accepted rescue method in patients with failed stone extraction under endoscopic retrograde cholangiopancreatography. Fully covered self-expanding metal stent (FCSEMS) has gained increasing attention in the management of difficult CBDS.

AIM

To manufacture a drug-eluting FCSEMS, which can achieve controlled release of stone-dissolving agents and speed up the dissolution of CBDS.

METHODS

Customized covered nitinol stents were adopted. Sodium cholate (SC) and disodium ethylene diamine tetraacetic acid (EDTA disodium, EDTA for short) were used as stone-dissolving agents. Three different types of drug-eluting stents were manufactured by dip coating (Stent I), coaxial electrospinning (Stent II), and dip coating combined with electrospinning (Stent III), respectively. The drug-release behavior and stone-dissolving efficacy of these stents were evaluated in vitro to sort out the best manufacturing method. And the selected stone-dissolving stents were further put into porcine CBD to evaluate their biosecurity.

RESULTS

Stent I and Stent II had obvious burst release of drugs in the first 5 d while Stent III presented controlled and sustainable drug release for 30 d. In still buffer, the final stone mass-loss rate of each group was 5.19% ± 0.69% for naked FCSEMS, 20.37% ± 2.13% for Stent I, 24.57% ± 1.45% for Stent II, and 33.72% ± 0.67% for Stent III. In flowing bile, the final stone mass-loss rate of each group was 5.87% ± 0.25% for naked FCSEMS, 6.36% ± 0.48% for Stent I, 6.38% ± 0.37% for Stent II, and 8.15% ± 0.27% for Stent III. Stent III caused the most stone mass-loss no matter in still buffer or in flowing bile, which was significantly higher than those of other groups (P < 0.05). In vivo, Stent III made no difference from naked FCSEMS in serological analysis (P > 0.05) and histopathological examination (P > 0.05).

CONCLUSION

The novel SC and EDTA-eluting FCSEMS is efficient in diminishing CBDS in vitro. When conventional endoscopic techniques fail to remove difficult CBDS, SC and EDTA-eluting FCSEMS implantation may be considered a promising alternative.

Predictors of failure of endoscopic retrograde cholangiography in clearing bile duct stone on the initial procedure

BACKGROUND/AIMS

The aim of this study is to predict cases where the clearance of the biliary system from stones at the initial endoscopic retrograde cholangiopancreatography (ERCP) might be of value for better risk-stratifying patients. We attempted to identify factors that are associated with a higher failure rate of clearing the biliary system on the index ERCP.

PATIENTS AND METHODS

This is a retrospective study from January 2008 to January 2015. All patients with bile duct stones confirmed on ERCP were included in this study. Patients who had prior attempts of bile duct stone extraction were excluded.

RESULTS

A total of 554 ERCPs were performed to extract biliary duct stones from 426 patients. The mean age was 46.3 years and 41.7% were males. The group where the index ERCP did not clear the biliary system tended to be older (50.4 vs. 45.2 years, P = 0.03). On multivariate analysis, the presence of fever (OR 4.64; 95% CI, 1.66-12.79), a larger number of filling defects (OR 1.34; 95% CI, 1.13-1.93), presence of a stricture distal to a stone (OR 4.63; 95% CI, 1.36-15.78), the use of an extraction basket (OR 3.23; 95% CI, 1.56-6.74), and/or mechanical lithotripsy (OR 3.05; 95% CI, 1.10-8.49) were all associated with a lower odds of clearing the biliary system. The use of an extraction balloon was associated with the success of clearing the biliary system (99.7% vs. 77.4%, P < 0.01) and a lower odds of failing (OR 0.01; 95% CI, 0.00-0.08) on multivariate analysis.

CONCLUSION

A few of the characteristics that are found on cholangiography at the index ERCP could be used to identify patients that might require more than one ERCP to clear the biliary system from stones.