Endoscopic ultrasound-guided choledochoduodenostomy as a primary treatment for malignant distal biliary obstruction: is it time for a randomized controlled study?

We read with great interest the article by Kawakubo et al. [1] reporting a retrospective comparative experience in performing endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) vs. standard endoscopic transpapillary stenting (ETS) as a primary treatment for malignant distal biliary obstruction. Clinical success rates were comparable between the two groups, with a significantly shorter procedure duration and a significantly lower rate of pancreatitis in patients who underwent EUS-CDS compared with those undergoing ETS. The need for reintervention at 1 year was similar in the two groups. All these results prompted the authors to conclude that EUS-CDS could be considered as a first-line treatment for patients with malignant distal biliary obstruction.

Although there has been great interest in this procedure over the past decade, with a growing number of publications, mostly reporting patients in whom ETS failed or was impossible, we believe that the data presented by Kawakubo et al. [1] are not sufficient to sustain their conclusions. Placement of the stent way above the malignant stricture in EUS-CDS could theoretically avoid stent occlusion caused by tissue ingrowth and result in a longer stent patency and a reduced need for reintervention compared with standard ETS. These inferences, however, need to be proven in a multicenter, randomized, controlled study with a well-defined patient population (i. e. patients with unresectable malignant distal biliary obstruction).

Another important question to be answered is which stent should be used to perform EUS-CDS? Up to now, standard self-expanding metal stents (SEMSs) designed to achieve biliary drainage with an ETS procedure have been used. However, these stents may have several limitations and may not be the most appropriate stents for the EUS-CDS procedure: i) they require fistulous tract formation to allow for stent penetration, which increase the risk of complications; ii) they do not give optimal lumen-to-lumen anchorage, which may result in bile leakage; iii) they may migrate, because there is no stricture to hold them in place; iv) the exposed ends of the stent may cause tissue trauma, resulting in bleeding or perforation. In view of these limitations, a lumen-apposing, fully covered, metal stent incorporated into a delivery system with an electrocautery device mounted on the tip (Hot Axios, Boston Scientific Corp., Marlborough, Massachusetts, USA) has recently been developed [2]. This device allows for a one-step procedure, without the need to exchange accessories [3] [4]. Moreover, it is highly visible by ultrasound, and the procedure can be performed mostly, if not completely, under endoscopic ultrasound guidance, with fluoroscopy kept as a backup [3] [4]. Data on the use of this stent for EUS-CDS remain scanty and limited to patients in whom standard ETS has failed, but they do seem promising [5]. In our opinion, it is this device that should be tested in future, adequately powered, randomized controlled trials.

Finally, another important question is how the next generation of endoscopists should be trained in performing EUS-guided biliary drainage. Recognition and proper visualization of a dilated bile duct from the duodenal bulb can be easily accomplished, but whether biliary drainage can be more easily learned and achieved under EUS guidance compared with the standard ETS procedure remains to be determined.

• References

• 1 Kawakubo K, Kawakami H, Kuwatani M et al. Endoscopic ultrasound-guided choledochoduodenostomy vs. transpapillary stenting for distal biliary obstruction. Endoscopy 2016; 48: 164-169
• 2 Rinninella E, Kunda R, Dollhopf M et al. EUS-guided drainage of pancreatic fluid collections using a novel lumen-apposing metal stent on an electrocautery enhanced delivery system: a large retrospective study. Gastrointest Endosc 2015; 82: 1039-1046
• 3 Attili F, Rimbaș M, Galasso D et al. Fluoroless endoscopic ultrasound-guided biliary drainage after failed ERCP with a novel lumen-apposing metal stent mounted on a cautery-tipped delivery system. Endoscopy 2015; 47: E619-E620
• 4 Tarantino I, Barresi L, Granata A et al. Single-step EUS-guided choledocoduodenostomy and stenting. Gastrointest Endosc 2015; 81: 1016-1017
• 5 Kunda R, Perez-Miranda M, Will U et al. EUS-guided choledochoduodenostomy for malignant distal biliary obstruction using a lumen-apposing fully covered metal stent after failed ERCP. Surg Endosc 2016; 2016 Mar 11. [Epub ahead of print] PubMed PMID: 26969661