Refractory late and chronic leaks or fistulas after sleeve gastrectomy (SG) and Roux-en-Y gastric bypass (RYGB) represent one of the most challenging post-bariatric complications. Endoscopic septotomy with argon plasma coagulation (ES-APC) facilitates internal drainage by incising the septum separating the perigastric cavity or fistulous tract from the gastric lumen. This study evaluated its efficacy and safety in a prospective cohort from a tertiary referral center.

Consecutive adults with refractory late or chronic post-bariatric leaks or fistulas treated with ES-APC between September 2019 and August 2025 were included. ES-APC consisted of stepwise ablation of the septum until complete luminal communication was achieved, followed by placement of a through-the-scope metallic clip at the base to promote localized ischemia and reduce bleeding or perforation risk.

A total of 64 patients were treated (76.6% female; mean age 40.8 ± 11.2 years; BMI 32.2 ± 7.7 kg/m²). Most complications occurred after SG (95.3%). At presentation, 48.4% had leaks, 48.4% fistulas, and 46.9% had an associated gastrocutaneous fistula (GCF). According to Rosenthal, 25% were late and 75% chronic. Patients had undergone a median of 4 prior treatments (IQR 3–5), with a median pretreatment duration of 106 days (IQR 79–138). Median number of ES-APC sessions was 1 (IQR 1–2), with a median procedural time of 15 min (IQR 12–22). Technical success was 100%. Clinical success (CS) was achieved in 93.7% (60/64), with only one recurrence (1.7%) during a median follow-up of 44 months (IQR 29–67). CS was significantly lower in patients with GCF (86.7% vs 100%, p=0.04). No major adverse events occurred.

ES-APC is a safe, standardized, and highly effective minimally invasive therapy for refractory late and chronic post-bariatric leaks and fistulas, providing durable closure while significantly reducing the need for surgery.