Thin Delivery Stents Can Obviate the Need for Additional Fistula Dilatation of Large Diameter in Endoscopic Ultrasound-Guided Hepaticogastrostomy

<b>Background/Objectives:</b> Endoscopic ultrasound-guided hepaticogastrostomy (EUS-HGS) often requires fistula dilation owing to the placement of a large diameter of the delivery stent. The recently developed delivery devices, which are as thin as 5.9/6.0 Fr, may save the need for fistula dilation. Therefore, we investigated whether large fistula dilation would be required or not in the case of this newly developed thin-diameter delivery stents. <b>Methods:</b> We conducted a retrospective study involving 33 patients implemented with a self-expandable metal stent (SEMS) during EUS-HGS. The patients were categorized based on the delivery device diameter into thin (n = 13; delivery device diameter: 5.9/6.0 Fr) and thick (n = 20; delivery device diameter: 8.5 Fr) groups. We compared the initial rate of success, technical success, and clinical success between the thin and thick groups. The initial rate of success was defined as successful stent placement without a balloon or large diameter mechanical dilation. <b>Results:</b> The rate of the initial stenting success was significantly higher in the thin group (100% [13/13]) compared with that in the thick group (65.0% [13/20]) (<i>p</i> = 0.027). In the thick group, seven cases with technical difficulty in terms of stent placement could be successfully completed with additional fistula dilation with a 9 Fr bougie dilator or 4 mm balloon dilator; this resulted in a technical success of 100% in both groups ultimately. The rate of clinical success was 100% and 95.0% in the thin and thick groups, respectively (<i>p</i> = 1.00). <b>Conclusions:</b> Thin delivery stents may facilitate stent placement without the need for a balloon fistula or large-diameter mechanical dilation.