Interventional strategies in infected necrotizing pancreatitis: Indications, timing, and outcomes

Figure 1 Mortality rates of acute pancreatitis and pathomechanisms. The mortality rate of all patients with acute pancreatitis (AP) is less than 10%. One-fifth of the patients developed necrotizing AP by ATP depletion, MLKL phosphorylation, acinar cell necroptosis, and/or acinar cell necrosis. One-third of the patients with necrotizing AP developed bacterial or fungal infection. The mortality rate of the infected necrotizing pancreatitis is up to 39%.

Figure 2 Endoscopic transluminal drainage with plastic stenting. A: A typical computed tomography (CT) scan with walled-off necrosis (WON) formed by necrotizing pancreatitis (white arrow shows stomach and yellow dotted line is the demarcation line of the WON); B: Endoscopic ultrasonography (EUS)-guided drainage for WON was performed (orange arrow shows the needle of 22-gauge EUS needle); C: Two plastic stents and nasobiliary drainage tube was placed into the WON; D: The size of the WON was reduced in the CT scan one month after the procedure. WON: Walled-off necrosis.

Figure 3 A case with endoscopic transluminal drainage with lumen-apposing metal stent. A: Computed tomography (CT) scan before performing the endoscopic ultrasonography (EUS)-guided drainage (White arrow shows the stomach and the yellow arrow shows the walled-off necrosis (WON); the yellow dotted line is the demarcation line of the WON); B: EUS (with color doppler) picture shows marked echoic lesion without vessels; C: Lumen-apposing metal stent (LAMS) and nasobiliary drainage tube were placed (white arrow shows LAMS: Hot AXIOS^TM 15 mm × 10 mm, Boston Scientific, Marlborough, MA, United States; Boston Scientific Japan, Tokyo, Japan); D: Esophagogastroduodenoscopy was inserted into necrotic cavity through LAMS; E: Necrosectomy was performed using endoscopic retrieval net; F: Endoscopic findings of the WON one month after the multiple necrosectomy sessions (2-3 times/wk); G: CT scan shows marked reduction of WON cavity one month after multiple necrosectomy sessions. WON: Walled-off necrosis; LAMS: Lumen-apposing metal stent.

Figure 4 Overview of the step-up approaches of infected necrotizing pancreatitis patients. In the acute phase, multidisciplinary treatment for acute pancreatitis is recommended. Endoscopic necrosectomy or surgical step-up should be considered if there no clinical improvement is observed within 72 h. Open necrosectomy should be considered after video-assisted retroperitoneal debridement or minimal access retroperitoneal pancreatic necrosectomy. ETN: Endoscopic transluminal necrosectomy; STE: Sinus tract endoscopy; ETD: Endoscopic transluminal drainage; PCD: Percutaneous catheter drainage; VARD: Video-assisted retroperitoneal debridement; MARPN: Minimal access retroperitoneal pancreatic necrosectomy.