Reply to Jin et al.

We thank Drs. Jin and Zhang for their interest in our study. We feel it is important to reiterate that endoscopic ultrasound-guided biliary drainage (EUS-BD) in primary biliary drainage for malignant obstruction is in its infancy, and therefore requires further prospective studies in large numbers of patients [1].

Study selection for our meta-analysis was performed using a priori inclusion and exclusion criteria. We then made the additional decision to exclude studies where patients had previous duodenal stenting, as this impacts the success rate of EUS-BD and endoscopic retrograde cholangiopancreatography (ERCP) [2]. Ultimately, this decision reduced the already-high statistical and methodological heterogeneity between included studies. Given this heterogeneity, we performed several sensitivity analyses, including removing each individual study from the analysis. Our overall findings remained unchanged.

Other sources of methodological heterogeneity were comprehensively explored in our discussion, including the use of different stent types. We reiterate that it is unknown what type of stent is optimal for EUS-BD and whether this choice depends on a transduodenal or transgastric approach. Although definitions of clinical success varied slightly between studies, all included studies reported high clinical success rates for both modalities, with no significant differences [1] between them.

Regarding study data from Paik et al. [3], the authors reported stent occlusion rates separately from re-interventions, and these events are thus reported in our forest plot comparing re-intervention rates. Nevertheless, we re-analyzed our data to include these events as stent occlusion and migration outcomes, and this does not change our overall stated results or conclusions.

We recognize the overall limitations of the included study data, and have elaborated on these at length in our discussion. Despite this, it appears that EUS-BD has comparable technical and clinical success rates to ERCP in the primary decompression of distal malignant biliary obstruction. We re-emphasize that future well-designed prospective studies are required to properly elucidate differences between EUS-BD and ERCP approaches in this context in terms of procedure times, adverse events, re-intervention rates, and cost.

• References

• 1 Bishay K, Boyne D, Yaghoobi M. et al. Endoscopic ultrasound-guided transmural approach versus ERCP-guided transpapillary approach for primary decompression of malignant biliary obstruction: a meta-analysis. Endoscopy 2019; DOI: 10.1055/a-0901-7343.
• 2 Hamada T, Isayama H, Nakai Y. et al. Transmural biliary drainage can be an alternative to transpapillary drainage in patients with an indwelling duodenal stent. Digest Dis Sci 2014; 59: 1931-1938
• 3 Paik WH, Lee TH, Park DH. et al. EUS-guided biliary drainage versus ERCP for the primary palliation of malignant biliary obstruction: a multicenter randomized clinical trial. Am J Gastroenterol 2018; 113: 987-997