Preliminary study of a modified, nonflared, short, fully covered metal stent for refractory benign pancreatic duct strictures (with videos)

Abstract

Background and aims: Fully covered self-expanding metal stents (FCSEMSs) are considered to be more effective than plastic stents for the treatment of main pancreatic duct (MPD) strictures associated with chronic pancreatitis (CP) because of their larger diameter and exertion of a radial expansion force. However, the current FCSEMSs have several limitations. To overcome these, a novel modified nonflared FCSEMS was developed. In this study we conducted a prospective long-term follow-up evaluation of the efficacy of the novel FCSEMS for the treatment of refractory benign PD strictures in patients with CP.

Methods: Consecutive patients with symptomatic CP associated with refractory MPD strictures were enrolled prospectively in this single-arm study. The nonflared FCSEMS was placed intraductally or transpapillary according to the location and length of the stricture. Stent removal was performed at 3 months after placement. The primary outcome was the resolution of the pancreatic ductal stricture.

Results: Endoscopic placement of modified nonflared FCSEMSs was technically successful in all 25 patients. Intraductal FCSEMS placement was performed in 14 patients (56.0%). Stents of diameter 8 mm were used in 17 patients (68.0%). Stents of lengths 3 and 5 cm were inserted in 22 (88.0%) and 3 (12.0%) patients, respectively. In 1 patient (4.0%), stent migration developed. All other stents were removed successfully. After stent removal, resolution of the MPD stricture was confirmed in all patients, and no FCSEMS-related de novo stricture was observed. During the follow-up period (median, 34 months; interquartile range, 25-56) after the stents had been removed from the 25 patients, reintervention for recurrence of MPD stricture with abdominal pain was performed in 2 patients (8.0%).

Conclusions: Endoscopic placement of a novel modified nonflared FCSEMS resulted in long-term stricture resolution with pain relief and reduced the rate of stent-related adverse events, particularly stent migration and stent-induced de novo MPD stricture. (Clinical trial registration number: UMIN000035681.).