Endoscopy 2016; 48(07): 689
DOI: 10.1055/s-0042-106724
Letters to the editor
© Georg Thieme Verlag KG Stuttgart · New York

# Reply to Saritas and Ustundag

Further Information

### Publication History

Publication Date:
28 June 2016 (online)

We thank Drs. Saritas and Ustundag for their interest and valuable comments [1] on our recent article comparing the yield of endoscopic ultrasound-guided choledochoduodenostomy (EUS-CDS) and endoscopic transpapillary stenting (ETS) in patients with malignant distal biliary obstruction [2].

As pointed out, the learning curve effect for EUS-CDS is an important issue. The specific expertise of each endoscopist for EUS-CDS and ETS was not shown in our study, and this lack of information was regarded as a limitation of the study [2]. Success in the EUS-CDS technique depends mainly on the expertise and skills of the operator (endoscopist). Another important component of technical success is the expertise of assistants for guidewire manipulation, fixation of the endoscope, and selection of devices. Despite lack of evidence, we currently suggest that 20 cases of EUS-CDS are sufficient for training and experience.

Some of the core technical training skills for EUS-CDS are: (i) visualizing the extrahepatic bile duct in the long axis from the duodenal bulb (operator), (ii) adjusting the direction of puncture toward the hepatic hilum (operator), (iii) fixing and keeping the endoscope in the duodenal bulb during visualization of the extrahepatic bile duct (second assistant), (iv) manipulation of the guidewire (0.025- or 0.035-inch hard type) and keeping it in the intrahepatic bile duct (first assistant), (v) use of a 6-Fr diathermic dilator (Cysto-Gastro-Set; Endo-Flex, GmbH, Voerde, Germany) for fistula creation between the duodenal bulb and the bile duct, and (vi) placement of a covered self-expandable metallic stent to prevent and minimize the possibility of bile leak and bleeding from the puncture site. A 6-Fr diathermic dilator is recommended because both the 8.5-Fr Cysto-Gastro-Set and the 10-Fr cystotome (Cook Medical, Bloomington, Indiana, USA) have larger diameters, resulting in a lower electric current density and a reduced diathermic effect, which are not sufficient for efficient fistula creation in terms of fistula size and procedure time.

As noted, various complications related to EUS-CDS have also been reported, such as bile leak [3] [4], stent dislocation [4] [5] [6], bleeding [3] [4], and perforation [3] [4]. However, procedure-related acute pancreatitis was not seen in our study [2]. At present, we should always be aware that there is no endoscopic retrograde cholangiopancreatography (ERCP) technique that can prevent post-ERCP pancreatitis completely [7] [8].

Regarding cost analysis, both ERCP and EUS-CDS are covered by insurance in Japan. The medical fee for EUS-CDS, excluding material cost, is JP ¥ 213 200 (about US $1887) and that for ETS is JP ¥ 115 400 (about US$ 1021). Therefore, at present, the cost of EUS-CDS is higher than that of ETS in Japan. However, the actual medical costs of EUS-CDS and ETS with regard to the management of complications were not analyzed [2]. In the near future, safety, feasibility, effectiveness, and all costs of EUS-CDS and ETS should be compared in a multicenter, randomized, controlled trial with a well-defined patient population and the expertise of multiple endoscopists.

Finally, in addition to the expertise of endoscopists, there is an urgent need for the development of dedicated devices (including stents) for safe, feasible, and effective EUS-CDS.