A comparative analysis of plastic biliary stenting on demand or every 3 months for irretrievable bile duct stone disease

We read with interest the article by Di Giorgio et al. titled “Endoscopic plastic stenting for bile duct stones: stent changing on demand or every 3 months. A prospective comparison study” [1]. In this article, the authors studied the rate of stone clearance and cholangitis in 78 patients with irretrievable stones in the common bile duct treated with endoscopic plastic biliary stenting. The primary aim of this study was to compare the rate of cholangitis in patients for whom two different strategies were applied for biliary plastic endoprosthesis implantation. The authors stated that the group of patients with stent changing every 3 months (group A) had a significantly lower cholangitis rate than the patient group with stent changing on demand (group B) (29 % vs. 36 %, P = 0.03). Nevertheless, the authors found similar rates of stone clearance in patients with stent changing on demand as compared with every 3 months (61.5 % vs. 53.8 %, respectively, P > 0.05).

This study compared two different strategies for treatment with plastic biliary stent insertion in patients with irretrievable bile duct stone disease. According to the study design, the plastic stents were changed every 3 months or sooner in the group A patients. In the group B patients, the plastic stents were changed “on demand,” as symptoms occurred or when there was an increase in the cholestasis index. This naturally means that for the patients within group B their plastic stents were changed when they developed either signs or symptoms of cholangitis or cholestasis. Thus, the meaningful difference between the two groups with respect to the rate of cholangitis is an expected one. More importantly, we wonder about the difference between the two groups in mortality rate, noted to be similar by the authors (P > 0.05). In other words, what we may understand from the results of this study is that the strategy of changing the plastic stents on demand did not lead to a higher rate of mortality than the strategy of stent changing every 3 months. This means that acute cholangitis in these patients can be successfully treated if started in time. In addition, there were 13 stent changes in patients in group A even before the scheduled 3 months, and overall, 166 plastic stent changes were done in this group of patients, which was three times greater than the total for the group B patients. Furthermore, this strategy does not remove the risk of developing cholangitis, since 3 of 39 patients developed acute cholangitis between the scheduled repeat stent changes. There are no cost–effectiveness data in this study. In addition, the regular stent-changing strategy can have potential hazards because of the frequent endoscopic retrograde cholangiopancreatography (ERCP) procedures, and its mortality rate is not zero. We also need to emphasize once again that the two groups of patients in this study showed a similar rate of stone clearance. Moreover, the statistical power in this study seems to be very low, since the total number of the patients enrolled was 78 and only 4 deaths associated with acute cholangitis were seen in the period of the treatment protocol.

Therefore, we believe that it is difficult to draw firm conclusions from this study, such as that the first strategy is better than the second according to the results obtained. Indeed, a similar study is needed, with the same design but enrolling a larger number of patients, and including cost–effectiveness data, to provide more conclusive results.

• Reference

• 1 Di Giorgio P, Manes G, Grimaldi E et al. Endoscopic plastic stenting for bile duct stones: stent changing on demand or every 3 months. A prospective comparison study. Endoscopy 2013; 45: 1014-1017