title: A systematic review and meta-analysis of pylorus-preserving versus classical pancreaticoduodenectomy for surgical treatment of periampullary and pancreatic carcinoma.
abstract: OBJECTIVE
  Comparison of effectiveness between the pylorus-preserving pancreaticoduodenectomy ("pylorus-preserving Whipple" [PPW]) and the classic Whipple (CW) procedure.
  
  
  METHODS
  A systematic literature search (Medline, Embase, Cochrane Library, Biosis, Science Citation Index, Ovid Journals) was performed to identify all eligible articles. Randomized controlled trials (RCTs) comparing PPW versus CW for periampullary and pancreatic carcinoma were eligible for inclusion. The methodologic quality of included studies was evaluated independently by 2 authors. Quantitative data on perioperative parameters (blood loss, transfusion, operation time, and length of hospital stay), mortality, morbidity, and survival were extracted from included studies for meta-analysis. Pooled estimates of overall treatment effect were calculated using a random effects model.
  
  
  RESULTS
  In total, 1235 abstracts were retrieved and checked for eligibility and 6 RCTs finally included. The critical appraisal revealed vast heterogeneity with respect to methodologic quality and outcome parameters. The comparison of overall in-hospital mortality (odds ratio, 0.49; 95% CI, 0.17 to 1.40; P = 0.18), morbidity (odds ratio 0.89; 95% CI, 0.48 to 1.62; P = 0.69), and survival (hazard ratio, 0.74; 95% CI, 0.52 to 1.07; P = 0.11) showed no significant difference. However, operating time (weighted mean difference, -68.26 minutes; 95% CI, -105.70 to -30.83; P = 0.0004), and intraoperative blood loss (weighted mean difference, -766 mL; 95% CI, -965.26 to -566.74; P = 0.00001) were significantly reduced in the PPW group.
  
  
  CONCLUSIONS
  Hence, in the absence of relevant differences in mortality, morbidity, and survival, the PPW seems to be as effective as the CW. Given obvious clinical and methodological interstudy heterogeneity, efforts should be intensified in the future to perform high quality RCTs of complex surgical interventions on the basis of well defined outcome parameters.
authors.affiliation: University of Heidelberg, Department of General, Visceral and Trauma Surgery, Heidelberg, Germany.
authors.forename: Markus K
authors.initials: MK
authors.lastname: Diener
authors.forename: Hanns-Peter
authors.initials: HP
authors.lastname: Knaebel
authors.forename: Christina
authors.initials: C
authors.lastname: Heukaufer
authors.forename: Gerd
authors.initials: G
authors.lastname: Antes
authors.forename: Markus W
authors.initials: MW
authors.lastname: Büchler
authors.forename: Christoph M
authors.initials: CM
authors.lastname: Seiler
mesh_terms: D014670:Ampulla of Vater; D006801:Humans; D010190:Pancreatic Neoplasms / Q000401:mortality / Q000601:surgery*; D016577:Pancreaticoduodenectomy / Q000379:methods*; D011708:Pylorus / Q000601:surgery*; D016032:Randomized Controlled Trials as Topic; D015996:Survival Rate / Q000639:trends; D016896:Treatment Outcome