Efficacy of chymotrypsin irrigation for endoscopically non-accessible walled-off necrosis in necrotizing pancreatitis.

Background and study aims: In necrotizing pancreatitis, incomplete debridement of necrotic tissue can result in persistent infection. This case series describes use of an innovative chymotrypsin irrigation technique for treatment of walled-off necrosis (WON). Patients and methods: Six patients with endoscopically non-accessible WON were treated with percutaneous catheter drainage (PCD) combined with chymotrypsin irrigation. In each session, 50 to 200 mL of a 120 U/mL chymotrypsin solution was instilled via the drainage catheter, retained for 30 minutes, and then gently flushed with 0.9% sodium chloride. The procedure was repeated once daily until radiologic resolution of the necrotic cavity was achieved. Results: WON was located in the pancreatic body/tail (n = 4), involved the entire pancreas (n = 1), or was subphrenic (n = 1). All lesions measured ≥ 6 cm in maximum diameter (largest: 21×10×23 cm). Complete radiologic resolution of the necrotic cavity was achieved in all patients after a median irrigation duration of 7 days (range 4-21 days). In two cases where endoscopic debridement was also performed, the necrotic tissue was notably softened, facilitating the procedure. No severe complications occurred and all patients completed the treatment course. Conclusions: Chymotrypsin irrigation effectively liquefies fibrotic necrotic tissue and promotes WON clearance via PCD, representing a promising adjunctive therapy for managing endoscopically non accessible WON.