Efficacy of self-expandable metal stents compared with multiple plastic stents in benign biliary strictures
29 May 2018 (online)
In an Editorial published in the same issue as the paper from Khan et al. on “Efficacy of self-expandable metal stents in management of benign biliary strictures and comparison with multiple plastic stents: a meta-analysis” , meta-analyses were defined as “the scientific epidemic of our times” . I am not an expert in meta-analyses, and I will probably not become one in the future; however, I can still see the difference between apples and oranges. I definitely do not agree with the conclusion of Khan et al.  that covered self-expandable metal stents (CSEMSs) have excellent efficacy in benign biliary strictures (BBSs). The right conclusion should be that CSEMSs have an excellent short-term efficacy in some types of BBS.
BBSs include a heterogeneous group of diseases, with different etiology, pathogenesis, morphology, pathology, and clinical expression. For instance, there is an obvious and substantial difference between a tapered stricture involving the entire lower third of the common bile duct (CBD) due to fibrotic compression from the pancreatic parenchyma in the setting of chronic pancreatitis and a short, angulated stricture due to bile duct injury during cholecystectomy, which often occurs close to the main hepatic confluence and sometimes even involves the right and the left hepatic ducts. While in the first scenario, CSEMSs seem a potentially logical solution (a multicenter randomized controlled trial comparing SEMSs to multiple plastic stents in the setting of chronic pancreatitis is currently recruiting – NCT01543256), there are no data suggesting that the use of SEMSs should currently be advocated for post-cholecystectomy CBD strictures.
Actually, the authors state that among the 1298 patients included in the analysis, 470 (36 %) had CBD strictures due to chronic pancreatitis, 264 (20 %) following orthotopic liver transplant, and 173 (13.5 %) had strictures related to choledocholithiasis, a very ill-defined condition. What about the remaining 391 patients (30 %)? Did these patients present with post-cholecystectomy strictures? Even if all these patients were post-cholecystectomy, 30 % does not correspond to the usual epidemiology: during the last 12 months, patients referred to our Unit with BBS amenable to stent therapy had post-cholecystectomy strictures in the majority of cases.
Meta-analyses should aim to provide the best available evidence on a specific matter; however, as in this case, when the data do not reflect daily clinical practice, they should be taken with cautious criticism.
- 1 Khan MA, Baron TH, Kamal F. et al. Efficacy of self-expandable metal stents in management of benign biliary strictures and comparison with multiple plastic stents: a meta-analysis. Endoscopy 2017; 49: 682-694
- 2 Rösch T, Repici A, Boeckxstaens G. Will reflux kill POEM?. Endoscopy 2017; 49: 625-628