title: Prophylactic pancreatic stent placement and post-ERCP pancreatitis: a systematic review and meta-analysis.
abstract: OBJECTIVE
  Pancreatitis is one of the most frequent complications of endoscopic retrograde cholangiopancreatography (ERCP). The placement of a prophylactic pancreatic stent after ERCP can help prevent post-ERCP pancreatitis (PEP). We aimed to provide an up-to-date meta-analysis regarding pancreatic stent placement for prevention of PEP and review the immediate adverse events associated with pancreatic stent placement.
  
  
  METHODS
  We conducted a systematic review and meta-analysis of randomized controlled trials (RCTs) considering pancreatic stent placement and the subsequent incidence of PEP. The primary outcome measure was the incidence of PEP. We also did a meta-analysis of RCTs and observational studies that reported on immediate adverse events, in order to estimate their incidence.
  
  
  RESULTS
  Eight studies, involving 680 patients, were included in the meta-analysis; 336 patients had pancreatic stent placement, and 344 patients formed the control group. Pancreatic stent placement was associated with a statistically significant reduction in PEP (relative risk [RR] 0.32, 95 % confidence interval [CI] 0.19 - 0.52; P<0.001). Subgroup analysis with stratification according to PEP severity showed that pancreatic stenting was beneficial in patients with mild to moderate PEP (RR 0.36, 95 %CI 0.22 -0.60; P<0.001) and in patients with severe PEP (RR 0.23, 95 %CI 0.06 - 0.91; P=0.04). Subgroup analysis according to patient selection demonstrated that pancreatic stenting was effective for both high risk and mixed-case groups. Weighted pooled estimates from between one and 17 studies for incidences of immediate adverse events were: overall complications 4.4 %; any infection 3.0 %; bleeding 2.5 %; cholangitis or cholecystitis 3.1 %; necrosis 0.4 %; pancreatic stent migration 4.9 % and occlusion 7.9 %; perforation 0.8 %; pseudocysts 3.0 %; and retroperitoneal perforation 1.2 %.
  
  
  CONCLUSIONS
  The meta-analysis shows that pancreatic stent placement after ERCP reduces the risk of PEP.
authors.affiliation: Division of Digestive Surgery, Department of Surgery, Nihon University School of Medicine, 2-11-1 Hikarigaoka, Nerima-ku, Tokyo, Japan. mazaki@med.nihon-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Mazaki
authors.forename: H
authors.initials: H
authors.lastname: Masuda
authors.forename: T
authors.initials: T
authors.lastname: Takayama
mesh_terms: D000208:Acute Disease; D002760:Cholangiopancreatography, Endoscopic Retrograde / Q000009:adverse effects*; D006801:Humans; D010195:Pancreatitis / Q000517:prevention & control*; D011183:Postoperative Complications / Q000517:prevention & control; D016032:Randomized Controlled Trials as Topic; D015607:Stents