Can we now recommend hydrogen peroxide for pancreatic necrosectomy? Time for controlled data

emerged as a first-line intervention for pancreatic walled-off necrosis (WON), either as solo therapy or as part of a minimally invasive step-up approach including percutaneous drainage and video assisted retroperitoneal debridement. In contrast to pancreatic pseudocysts, for which resolution is expected following transmural drainage and stent placement, WON represents a distinct clinical entity often requiring additional method(s) of endoscopic intervention including endoscopic transmural retroperitoneal necrosectomy. Technical aspects of EUS-guided intervention have evolved from off-label use of endoscopic retrograde cholangiopancreatography accessories to dedicated drainage devices, specifically lumen apposing metal stents (LAMS). Some of these devices allow access to WON using an electrocautery-enhanced delivery catheter, followed by deployment of a LAMS with a luminal diameter sufficient to both provide robust drainage and serve as an entry port for endoscopic necrosectomy. Multicenter retrospective data have demonstrated high rates of both technical and clinical success following endoscopic therapy of WON with LAMS, with an acceptable adverse event rate and a low requirement for additional non-endoscopic interventions [1]. Yet even LAMS are not a panacea, as they can be subject to luminal occlusion and requirement for endoscopic re-intervention, and numerous questions still abound regarding optimal technical aspects of endoscopic management of WON. Should endoscopic necrosectomy be performed during the index procedure or deferred to a second-stage procedure following stent placement and tract maturation? Is a single transmural drainage site sufficient or should multiport drainage be considered? When should a nasocystic tube be placed to allow for irrigation of the necrotic cavity? What is the role of either endogenous (gastric acid) or exogenous chemical debridement of the cavity? The last question is the subject of the study presented in this issue of Endoscopy International Open by Bansal et al, who report the results of a prospective open-label study. Study subjects underwent EUS-guided drainage of WON with placement of a fully covered self-expanding metal stent, followed by step-up therapy including endoscopic necrosectomy using hydrogen peroxide [2]. Use of hydrogen peroxide as an adjunct to endoscopic necrosectomy has been previously described. Siddiqui et al reported a case series of 14 patients who underwent EUS-guided drainage and necrosectomy, several of whom required no further debridement following lavage with 100 cc to 500 cc of 3% hydrogen peroxide at 1:5–1:10 dilution [3]. And in the previously referenced multicenter retrospective study of endoscopic therapy of WON using LAMS, 31% (38/124) of patients were treated with hydrogen peroxide [1]. In the current study by Bansal et al, luminal stent occlusion by necrotic debris was relieved using a snare or forceps—otherwise by protocol all further necrosectomy was performed via hydrogen peroxide lavage, and no intracavitary mechanical debridement was permitted. Among 64 patients included in the analysis, technical success was reported in 100% and clinical success was reported in 90.6%. Mean number of necrosectomy sessions was 3.2 (range 1–5). Five patients required perCan we now recommend hydrogen peroxide for pancreatic necrosectomy? Time for controlled data