Innocent as a LAMS: Does Spontaneous Fistula Closure (Secondary Intention), After EUS-Directed Transgastric ERCP (EDGE) via 20-mm Lumen-Apposing Metal Stent, Confer an Increased Risk of Persistent Fistula and Unintentional Weight Gain?

Background and Aims Persistent gastrogastric or jejunogastric fistula is theoretically a concerning sequela of EUS-directed transgastric ERCP/EUS (EDGE), as it may functionally reverse the malabsorptive mechanism of Roux-en-Y gastric bypass (RYGB). Prior EDGE studies, using predominantly 15-mm (diameter) lumen-apposing metal stents (LAMS) and fistula closure by primary intent, collectively report 9% persistent fistula rate, without a clear weight gain association. Our study determines the incidence of persistent fistula, and its association with unintentional weight gain, among recipients of EDGE via 20-mm LAMS followed by spontaneous fistula closure (secondary intent). Methods We conducted a dual-center prospective cohort study of 22 RYGB patients who underwent EDGE using 20-mm between 3/2018 and 10/2019. After LAMS extraction, all GGFs/JGFs were allowed to heal spontaneously. Objective testing for persistent fistula and total body weight (TBW) occurred a minimum of 8 weeks after LAMS extraction. Results Persistent fistula was identified in 9 patients (41%). Longer LAMS dwell time (median 77-days) was observed in the persistent fistula group, compared to those with durable spontaneous fistula closure (median 35-days) (p = 0.03). Weight gain of >= 5% TBW occurred in 56% (n = 5) of patients with persistent fistula, compared to 15% (n = 2) of patients with spontaneous fistula closure (p = 0.128). Four patients with symptomatic persistent fistulas underwent attempted endoscopic fistula closure a median 7.5 months after LAMS extraction. Durable fistula closure occurred in the single patient who received argon plasma coagulation plus endoscopic suturing, whereas fistula dehiscence occurred in 3/3 (100%) patients with endoscopic suturing monotherapy. Conclusions Larger LAMS diameter (20-mm), longer LAMS dwell time, and spontaneous fistula closure may be technical factors that increase the likelihood of post-EDGE persistent fistula. Post-EDGE persistent fistula has not been shown by ours or other studies to be significantly associated with unintentional weight gain; however, this may be due to small sample size. We question the utility of routine fistula closure by primary intent and suggest a personalized approach to post-EDGE fistula management.

Automated summary

This study used 20mm LAMS for EDGE followed by spontaneous fistula closure to determine the incidence of persistent fistula and its association with unintentional weight gain. The study found that longer LAMS dwell time and spontaneous fistula closure may increase the likelihood of post-EDGE persistent fistula, but this condition has not been significantly associated with weight gain in the small sample size. A personalized approach to post-EDGE fistula management is suggested.