Endoscopic transluminal drainage and necrosectomy for infected necrotizing pancreatitis: Progress and challenges

Table 1 Characteristics of endoscopic transluminal drainage and stents

	Recommendations and benefits	Areas of concern	Ref.
Recommending EUS guidance	Effective and minimally invasive; lower morbidity; reduced reinterventions; decreased follow-up imaging; shorter hospital stay	-	[18-21,24,25,66]
Indications for drainage	INP-associated symptoms and complications	Patients' general conditions and symptoms; PFC characteristics; endoscopic experience	[27-28]
Timing of intervention
Early intervention (< 2 wk)	Not recommended; no superiority in complications	Increased mortality and invasive interventions	[5,45]
Early intervention (3–4 wk)	Safe and effective when identifying a partial collection	Increased mortality, endoscopic necrosectomy, and rescue surgery	[14,50,51]
Delayed intervention (> 4 wk)	Generally recommended; after INP encapsulation; excellent clinical success; reduced reinterventions and mortality	-	[17,45-49]
Stents
DPPS	Affordable, safe, and easily accessible; recommended for little debris (≤ 10 %) or pure PPC	Stent occlusion; possible leakage; limited endoscopic access to the necrotic cavity	[18,28-30,54,57]
SEMS	Feasible; deployed when LAMS is unavailable	-	[32]
LAMS	Simpler procedure; higher technical and long-term success rates; less AD than DPPS; recommended for significant debris (≥ 30 %)	Higher cost; increased risks of pseudoaneurysm bleeding, delayed bleeding, perforation, and buried stent syndrome	[12,29,33,34,52-55,60-63]
Negative predictors for drainage effect	Male; MOF; extensive necrosis (≥ 150 mm); heterogeneity (necrosis ≥ 50%)	-	[35-37]
Improving drainage	Additional nasocystic drainage; multiple transluminal gateway technique; hybrid techniques	-	[28,31,38,39,42,43]
Technical aspects	Not always requiring fluoroscopy and LAMS dilation; novel techniques for complicated deployments; timely stent removal; endoscopic closure for patients with a poor situation or early needs for transoral feeding	Lack of standardized protocol	[11,12,17,61,62,68,69]

EUS: Endoscopic ultrasound; INP: Infected necrotizing pancreatitis; PPC: Pancreatic pseudocyst; PFC: Pancreatic fluid collection; DPPS: Double-pigtail plastic stents; SEMS: Self-expanding metal stents; LAMS: Lumen-apposing metal stents; AD: Adverse events; MOF: Multiple organ failure.

Table 2 Characteristics of endoscopic transluminal necrosectomy

	Recommendations and benefits	Areas of concern	Ref.
Indications for necrosectomy	Unsolved INP-associated symptoms	Conservative management or endoscopic drainage alone is sufficient in selected patients	[77-80]
Endoscopic transluminal necrosectomy	First-line therapy; recommended endoscopic step-up approach; increased life quality; reduced proinflammatory response, complications, hospitalization time, costs, and new-onset multiple organ failure	One single treatment may not suit all INP patients; no superiority in reducing major complications or mortality when compared with the surgical step-up procedure	[6,8-10,71,83-85]
Improve necrosectomy efficiency	A solid component is better assessed by EUS than by CT scanning	Lack of unified assessment protocol for necrosis proportion	[54]
Irrigation techniques	A three-step structured approach; saline, streptokinase, antibiotics, and hydrogen peroxide; reduced mortality and debridements	Lack of optimal procedure and concentration; prolonged stent retrieval; perforation caused by forced irrigation	[79,86-97]
Dedicated instruments	OTSG; PED; WAND; safe and effective; reduced interventions and hospital duration	Efficacy and indispensable safety; further research and popularization	[98-100]
Predictors for complications	Small size (≤ 7 cm) and delayed stent removal (≥ 4 w); PD disruption, abnormal vessels, and requirements of percutaneous drainage or hybrid techniques; elevated intracavitary amylase; exocrine insufficiency	Lack of prospective multicenter large-scale RCT	[37,106-109]
Managing complications	A novel algorithm for systematically managing hemorrhage events; LAMS with a larger diameter; mouthwash with chlorhexidine; suspension of PPI; timely follow-up and endoscopic management		[60,62,63,74,79,101-104]
MDT strategy	Individualized treatment; reduced mortality; improved clinical outcomes; optimal strategy for patients with high risks of potential complications	Lack of standardized endoscopic protocol; considerable variations among endoscopists	[11,79,110-112]

EUS: Endoscopic ultrasound; INP: Infected necrotizing pancreatitis; OTSG: Over-the-scope grasper; PED: Powered endoscopic debridement system; WAND: Waterjet necrosectomy device; PD: Pancreatic duct; RCT: Randomized controlled trials; LAMS: Lumen-apposing metal stents; MDT: Multi-disciplinary treatment.